Environmental challenges to operationalisation of South African rainfall enhancement

Most of the atmospheric moisture in systems moving across South Africa leaves the sub-continent as the weather systems move out over the ocean, only a tenth of it falls on the landmass as rain. An increase in the efficiency of the atmospheric moisture delivery system by means of rainfall enhancement is therefore an attractive concept. Rainfall enhancement functions by either providing additional Cloud Condensation Nuclei or Ice forming Nuclei that will beneficially influence the precipitation formation process, improving the efficiency of moisture to rainfall conversion. Systematic South African research into rainfall enhancement started in the 1970s. The South African Rainfall Enhancement Programme (SAREP), initiated in the late 1990\'s, is the most recent in a series of studies and was the first semi-operational rainfall enhancement project to occur in South Africa as a response to drought conditions. In a recent study (DWAF, 2004 in prep) to finalise SAREP and provide guidance on operationalising rainfall enhancement, it was recommended that environmental impact assessment must be undertaken before this technology is implemented further. Rainfall enhancement falls specifically within the jurisdiction of the National Water Act (NWA) and the National Environmental Management Act (NEMA). A licence to undertake rainfall enhancement activities is required from the Minister of Water Affairs and Forestry after an appropriate environmental impact assessment has been undertaken to inform his decision. This paper proposes an approach to fulfil the legal requirements for operationalising future rainfall enhancement. The interaction between the science of rainfall enhancement and the ability of scientific disciplines to determine relevant environmental impacts, to appropriately inform the decision-making process, is specifically highlighted. The data requirements identified by scientists during the study varies in duration and resource needs and does not differentiate between ongoing scientific research and the requisite information required for informed decision making. This paper contemplates an approach which provides for holistic and co-ordinated investigation of South African rainfall enhancement into the future. Water SA Vol. 30 (5) 2005: pp.88-9

Measurement invariance of cognitive and affective job insecurity: A cross-national study

Empirical evidence of established measurement invariance of job insecurity measures may enhance the practical utility of job insecurity as a valid predictor when utilised over different cross-national samples. This study investigated the measurement invariance of the nine-item versions of the Job Security Index (a measure of cognitive job insecurity) and the Job Security Satisfaction Scale (a measure of affective job insecurity), across four countries (i.e. the United States, N = 486; China, N = 629; Italy, N = 482 and South Africa, N = 345). Based on a novel bifactor-(S-1) model approach we found evidence for partial metric, partial scalar and partial strict invariance of our substantive bifactor-(S-1) structure. The results extend measurement invariance research on job insecurity with obvious pragmatic implications (e.g. scaling units, measurement bias over cross-national interpretations). Contribution: This research provides evidence to support the applied use of cross-national comparisons of job insecurity scores across the nationalities included in this study. Theoretically, this research advances the debate about the nature of the relationship between cognitive and affective job insecurity, suggesting that in this cross-national dataset, a model where cognitive job insecurity is specified as the reference domain outperforms a model where affective job insecurity is assigned this status. Practically, it demonstrates that it is sensible and necessary to differentiate between cognitive and affective job insecurity and include measures of both constructs in future research on the construct

Indicators for monitoring reduced impact logging in the Brazilian amazon derived from airborne laser scanning technology.

Monitoring reduced impact logging (RIL) activities in sustainably managed forest areas in the Amazon is a costly and complex, yet crucial endeavor. One viable monitoring option is the use of airborne laser scanning (LiDAR), which enables estimating forest structure parameters over large areas in a reduced timeframe with high accuracy. In this study, we propose and assess the applicability of five monitoring indicators for RIL based on Light Detection and Ranging (LiDAR) data acquisition in areas under forest concession

Neutrophils in cancer: neutral no more

Neutrophils are indispensable antagonists of microbial infection and facilitators of wound healing. In the cancer setting, a newfound appreciation for neutrophils has come into view. The traditionally held belief that neutrophils are inert bystanders is being challenged by the recent literature. Emerging evidence indicates that tumours manipulate neutrophils, sometimes early in their differentiation process, to create diverse phenotypic and functional polarization states able to alter tumour behaviour. In this Review, we discuss the involvement of neutrophils in cancer initiation and progression, and their potential as clinical biomarkers and therapeutic targets

Influence of short term storage conditions, concentration methods and excipients on extracellular vesicle recovery and function

Extracellular vesicles (EVs) are phospholipid bilayer enclosed vesicles which play an important role in intercellular communication. To date, many studies have focused on therapeutic application of EVs. However, to progress EV applications faster towards the clinic, more information about the physical stability and scalable production of EVs is needed. The goal of this study was to evaluate EV recovery and function after varying several conditions in the isolation process or during storage. Physical stability and recovery rates of EVs were evaluated by measuring EV size, particle and protein yields using nanoparticle tracking analysis, microBCA protein quantification assay and transmission electron microscopy. Western blot analyses of specific EV markers were performed to determine EV yields and purity. EV functionality was tested in an endothelial cell wound healing assay. Higher EV recovery rates were found when using HEPES buffered saline (HBS) as buffer compared to phosphate buffered saline (PBS) during EV isolation. When concentrating EVs, 15 ml spinfilters with a 10 kDa membrane cutoff gave the highest EV recovery. Next, EV storage in polypropylene tubes was shown to be superior compared to glass tubes. The use of protective excipients during EV storage, i.e. bovine serum albumin (BSA) and Tween 20, improved EV preservation without influencing their functionality. Finally, it was shown that both 4 °C and −80 °C are suitable for short term storage of EVs. Together, our results indicate that optimizing buffer compositions, concentrating steps, protective excipients and storage properties may collectively increase EV recovery rates significantly while preserving their functional properties, which accelerates translation of EV-based therapeutics towards clinical application

Positive Psychology in Sales: Integrating Psychological Capital

As positive psychology moves into the workplace, researchers have been able to demonstrate the desirable impact of positive organizational behavior. Specifically, psychological capital (PsyCap) improves employee attitudes, behaviors, and performance. Advancing PsyCap in sales research is important given the need for a comprehensive positive approach to drive sales performance, offset the high cost of salesperson turnover, improve cross-functional sales interfaces, and enrich customer relationships. The authors provide an integrative review of PsyCap, discuss its application in sales, and advance an agenda for future research. Research prescriptions are organized according to individual-level, intra-organizational, and extra-organizational outcomes pertinent to the sales field

Polymorphisms of genes coding for ghrelin and its receptor in relation to colorectal cancer risk: a two-step gene-wide case-control study

<p>Abstract</p> <p>Background</p> <p>Ghrelin, an endogenous ligand for the growth hormone secretagogue receptor (GHSR), has two major functions: the stimulation of the growth hormone production and the stimulation of food intake. Accumulating evidence also indicates a role of ghrelin in cancer development.</p> <p>Methods</p> <p>We conducted a case-control study to examine the association of common genetic variants in the genes coding for ghrelin (GHRL) and its receptor (GHSR) with colorectal cancer risk. Pairwise tagging was used to select the 11 polymorphisms included in the study. The selected polymorphisms were genotyped in 680 cases and 593 controls from the Czech Republic.</p> <p>Results</p> <p>We found two SNPs associated with lower risk of colorectal cancer, namely SNPs rs27647 and rs35683. We replicated the two hits, in additional 569 cases and 726 controls from Germany.</p> <p>Conclusion</p> <p>A joint analysis of the two populations indicated that the T allele of rs27647 SNP exerted a protective borderline effect (P_trend= 0.004).</p

Assessing biomass based on canopy height profiles using airborne laser scanning data in eucalypt plantations

This study aimed to map the stem biomass of an even-aged eucalyptus plantation in southeastern Brazil based on canopy height profile (CHPs) statistics using wall-to-wall discrete return airborne laser scanning (ALS), and compare the results with alternative maps generated by ordinary kriging interpolation from field-derived measurements. The assessment of stem biomass with ALS data was carried out using regression analysis methods. Initially, CHPs were determined to express the distribution of laser point heights in the ALS cloud for each sample plot. The probability density function (pdf) used was the Weibull distribution, with two parameters that in a secondary task, were used as explanatory variables to model stem biomass. ALS metrics such as height percentiles, dispersion of heights, and proportion of points were also investigated. A simple linear regression model of stem biomass as a function of the Weibull scale parameter showed high correlation (adj.R2 = 0.89). The alternative model considering the 30th percentile and the Weibull shape parameter slightly improved the quality of the estimation (adj.R2 = 0.93). Stem biomass maps based on the Weibull scale parameter doubled the accuracy of the ordinary kriging approach (relative root mean square error = 6 % and 13 %, respectively)

Developing core competencies for monitoring and evaluation tracks in South Asian MPH programs

Background: Monitoring and evaluation (M&E) provides vital information for decision-making and its structures, systems and processes are expected to be integrated throughout the life-cycle of public health programs. The acquisition of these skills should be developed in a structured manner and needs educational systems to identify core competencies in M&E teaching. This article presents our work on harmonizing M&E competencies for Masters level programs in the South Asian context and undertaking the global review of M&E track/ concentration offered in various Masters of Public Health (MPH) programs. Methods: Through an online search and snow-balling, we mapped institutions offering M&E tracks/ concentrations in Masters of Public Health (MPH) programs globally. We obtained detailed information about their M&E curriculum from university websites and brochures. The data on curricular contents was extracted and compiled. We analyzed the curricular contents using the framework for core competencies developed by the Association of Schools of Public Health (ASPH); and the Miller’s triangle. This data was then used to inform a consultative exercise aimed at identifying core competencies for an M&E track/ concentration in MPH programs in the South Asian context. Results: Our curricular review of M&E content within MPH programs globally showed that different domains or broad topic areas relating to M&E are covered differently across the programs. The quantitative sciences (Biostatistics and Epidemiology) and Health Policy and Management are covered in much greater depth than the other two domains (Social & Behavioral Sciences and Environmental Health Sciences). The identification of core competencies for an M&E track/ concentration in the South Asian context was undertaken through a consultative group exercise involving representation from 11 institutions across Bangladesh, India, Nepal and Sri Lanka. During the consultation, the group engaged in a focused discussion to reach consensus on a set of 15 core competencies for an M&E track in South Asian MPH programs. Conclusion: This work presents an opportunity for institutions to identify and re-examine their M&E competencies as a part of their specialized tracks within MPH programs. Our curricular analysis approach has the potential for adaptation and further use in curriculum analysis across different academic specialties

Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome

Differentiation of hematopoietic stem cells is regulated by a concert of different transcription factors. Disturbed transcription factor function can be the basis of (pre)malignancies such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Growth factor independence 1b (Gfi1b) is a repressing transcription factor regulating quiescence of hematopoietic stem cells and differentiation of erythrocytes and platelets. Here, we show that low expression of Gfi1b in blast cells is associated with an inferior prognosis of MDS and AML patients. Using different models of human MDS or AML, we demonstrate that AML development was accelerated with heterozygous loss of Gfi1b, and latency was further decreased when Gfi1b was conditionally deleted. Loss of Gfi1b significantly increased the number of leukemic stem cells with upregulation of genes involved in leukemia development. On a molecular level, we found that loss of Gfi1b led to epigenetic changes, increased levels of reactive oxygen species, as well as alteration in the p38/Akt/FoXO pathways. These results demonstrate that Gfi1b functions as an oncosuppressor in MDS and AML development