Modeling the Marginal Revenue of Water in Selected Agricultural Commodities: A Panel Date Approach

South Africa is a water-stressed country where water availability is an important constraint to economic and social development, and will become even more so in the future if this scarce resource is not managed effectively. In order to manage this scarce supply of water, we need to value it. This study focuses on the value of water in the agricultural sector, in particular the marginal revenue of water for six irrigation commodities namely avocados, bananas, grapefruit, mangoes, oranges and sugarcane. A quadratic production function was fitted with an SUR model specification in a panel data study from 1975 to 2002 to obtain marginal revenue functions for each of the six commodities. We found that mangoes are the most efficient commodity in its water use relative to revenue generated (marginal revenue of water equals R25.43/m3 in 2002) and sugarcane the least efficient (marginal revenue of water equals R1.67/m3 in 2002). The marginal revenue of water is not an indication of the true “market” price. Neither is it an indication what the administered price should be. The marginal revenue of water is rather a guideline for policy makers to determine which industries or commodities within an industry can generate the largest revenue per unit water applied.Marginal revenue, water efficiency, panel data

The combined honours student experience survey data and the perceptions of staff and students

Data analysis from the University Student Survey (2016) at Canterbury Christ Church University revealed that combined honours students (n=780) were less satisfied than single honours students. The qualitative comments of the students referred to concerns about identifying with and belonging to the programme; and self confidence. In addition, on one programme (n=89), combined honours student were less satisfied than their single honours classmates on 18 of the 22 USS satisfaction measure statements. Three focus group with staff on this programme (n=18) and interviews with students (n=8) were undertaken to investigate the issues of lack of satisfaction further. This paper will report on the ongoing investigation and the potential development of learning and teaching interventions

Sclerosing epithelioid fibrosarcoma as a rare cause of ascites in a young man: a case report

<p>Abstract</p> <p>Introduction</p> <p>Sclerosing epithelioid fibrosarcoma is a rare but distinct variant of fibrosarcoma that not only presents as a deep-seated mass on the limbs and neck but can also occur adjacent to the fascia or peritoneum, as well as the trunk and spine. We report the case of an intra-abdominal sclerosing epithelioid fibrosarcoma, which to best of the authors' knowledge has not been described previously. The patient discussed here developed lung metastases but is still alive 1-year post-diagnosis.</p> <p>Case presentation</p> <p>A 29-year-old man presented with a 2-week history of progressive abdominal distension and pain and was found to have marked ascites. A full liver screen was unremarkable with abdominal and chest computed tomography scans only confirming ascites. After a diagnostic laparotomy, biopsies were taken from the greater omentum and peritoneal nodules. Histopathology revealed a malignant tumour composed of sheets and cords of small round cells set in collagenized stroma. After further molecular investigation at the Mayo Clinic, USA, the diagnosis of a high-grade sclerosing epithelioid fibrosarcoma was confirmed.</p> <p>Conclusion</p> <p>Sclerosing epithelioid fibrosarcoma is an extremely rare tumour, which is often difficult to diagnose and which few pathologists have encountered. This case is particularly unusual because of the intra-abdominal origin of the tumour. Owing to the rarity of sclerosing epithelioid fibrosarcoma, there is no clear evidence regarding the prognosis of such a tumour, although sclerosing epithelioid fibrosarcoma is able to metastasize many years post-presentation. It is important that physicians and pathologists are aware of this unusual tumour.</p

A systematic review of the neurobiological underpinnings of borderline personality disorder (BPD) in childhood and adolescence

Contemporary theories for the aetiology of borderline personality disorder (BPD) take a lifespan approach asserting that inborn biological predisposition is potentiated across development by environmental risk factors. In this review, we present and critically evaluate evidence on the neurobiology of BPD in childhood and adolescence, compare this evidence to the adult literature, and contextualise within a neurodevelopmental framework. A systematic review was conducted to identify studies examining the neurobiological (i.e. genetic, structural neuroimaging, neurophysiological, and neuropsychological) correlates of BPD symptoms in children and adolescents aged 19 years or under. We identified, quality assessed, and narratively summarised 34 studies published between 1980 and June 2016. Similar to findings in adult populations, twin studies indicated moderate to high levels of heritability of BPD, and there was some evidence for gene-environment interactions. Also consistent with adult reports is that some adolescents with BPD demonstrated structural (grey and white matter) alterations in frontolimbic regions and neuropsychological abnormalities (i.e. reduced executive function and disturbances in social cognition). These findings suggest that neurobiological abnormalities observed in adult BPD may not solely be the consequence of chronic morbidity or prolonged medication use. They also provide tentative support for neurodevelopmental theories of BPD by demonstrating that neurobiological markers may be observed from childhood onwards and interact with environmental factors to increase risk of BPD in young populations. Prospective studies with a range of repeated measures are now required to elucidate the temporal unfurling of neurobiological features and further delineate the complex pathways to BPD

Lateral membrane organization as target of an antimicrobial peptidomimetic compound

Antimicrobial resistance is one of the leading concerns in medical care. Here we study the mechanism of action of an antimicrobial cationic tripeptide, AMC-109, by combining high speed-atomic force microscopy, molecular dynamics, fluorescence assays, and lipidomic analysis. We show that AMC-109 activity on negatively charged membranes derived from Staphylococcus aureus consists of two crucial steps. First, AMC-109 self-assembles into stable aggregates consisting of a hydrophobic core and a cationic surface, with specificity for negatively charged membranes. Second, upon incorporation into the membrane, individual peptides insert into the outer monolayer, affecting lateral membrane organization and dissolving membrane nanodomains, without forming pores. We propose that membrane domain dissolution triggered by AMC-109 may affect crucial functions such as protein sorting and cell wall synthesis. Our results indicate that the AMC-109 mode of action resembles that of the disinfectant benzalkonium chloride (BAK), but with enhanced selectivity for bacterial membranes.</p

Foetal haemoglobin-blood cells (F-cells) as a feature of embryonic tumours (blastomas)

Tumour markers are important in the diagnosis and monitoring of many tumours. This study tested the hypothesis that an oncofoetal protein, foetal haemoglobin (HbF) is a potential tumour marker in embryonic tumours, useful for management. An immunohistochemical investigation of HbF blood cell (Fc) distribution was carried out in tumours and in bone marrow samples from 83 children and 13 adults with various embryonic tumours (blastomas), and in bone marrow samples of 24 leukaemia patients. In the three, main blastoma types, nephroblastoma (Wilms' tumour), neuroblastoma and retinoblastoma, where all the patients, except two, were children, around 80% of the tumour samples had Fc within proliferating blood vessels and spaces between tumour cells. In parallel, clusters of Fc, mostly F-erythroblasts (Feb), were distributed in the bone marrow of some of those patients and in the bone marrow of 79% of the leukaemia patients. Foetal haemoglobin, as well as being a potential prognostic cancer marker, is a potential indicator of DNA hypomethylation implicated in the development of these tumours, as well as in others previously noted for the presence of HbF

Stromal Fibroblasts in Digestive Cancer

The normal gastrointestinal stroma consists of extra-cellular matrix and a community of stromal cells including fibroblasts, myofibroblasts, smooth muscle cells, pericytes, endothelium and inflammatory cells. α-smooth muscle actin (α-SMA) positive stromal fibroblasts, often referred to as myofibroblasts or activated fibroblasts, are critical in the development of digestive cancer and help to create an environment that is permissive of tumor growth, angiogenesis and invasion. This review focusses on the contribution of activated fibroblasts in carcinogenesis and where possible directly applies this to, and draws on examples from, gastrointestinal cancer. In particular, the review expands on the definition, types and origins of activated fibroblasts. It examines the molecular biology of stromal fibroblasts and their contribution to the peritumoral microenvironment and concludes by exploring some of the potential clinical applications of this exciting branch of cancer research. Understanding the origin and biology of activated fibroblasts will help in the development of an integrated epithelial-stromal sequence to cancer that will ultimately inform cancer pathogenesis, natural history and future therapeutics

Origin of myofibroblasts in liver fibrosis

Most chronic liver diseases of all etiologies result in progressive liver fibrosis. Myofibroblasts produce the extracellular matrix, including type I collagen, which constitutes the fibrous scar in liver fibrosis. Normal liver has little type I collagen and no detectable myofibroblasts, but myofibroblasts appear early in experimental and clinical liver injury. The origin of the myofibroblast in liver fibrosis is still unresolved. The possibilities include activation of endogenous mesenchymal cells including fibroblasts and hepatic stellate cells, recruitment from the bone marrow, and transformation of epithelial or endothelial cells to myofibroblasts. In fact, the origin of myofibroblasts may be different for different types of chronic liver diseases, such as cholestatic liver disease or hepatotoxic liver disease. This review will examine our current understanding of the liver myofibroblast

PDGF-Rα gene expression predicts proliferation, but PDGF-A suppresses transdifferentiation of neonatal mouse lung myofibroblasts

<p>Abstract</p> <p>Background</p> <p>Platelet-derived growth factor A (PDGF-A) signals solely through PDGF-Rα, and is required for fibroblast proliferation and transdifferentiation (fibroblast to myofibroblast conversion) during alveolar development, because <it>pdgfa</it>-null mice lack both myofibroblasts and alveoli. However, these PDGF-A-mediated mechanisms remain incompletely defined. At postnatal days 4 and 12 (P4 and P12), using mouse lung fibroblasts, we examined (a) how PDGF-Rα correlates with ki67 (proliferation marker) or alpha-smooth muscle actin (αSMA, myofibroblast marker) expression, and (b) whether PDGF-A directly affects αSMA or modifies stimulation by transforming growth factor beta (TGFβ).</p> <p>Methods</p> <p>Using flow cytometry we examined PDGF-Rα, αSMA and Ki67 in mice which express green fluorescent protein (GFP) as a marker for PDGF-Rα expression. Using real-time RT-PCR we quantified αSMA mRNA in cultured Mlg neonatal mouse lung fibroblasts after treatment with PDGF-A, and/or TGFβ.</p> <p>Results</p> <p>The intensity of GFP-fluorescence enabled us to distinguish three groups of fibroblasts which exhibited absent, lower, or higher levels of PDGF-Rα. At P4, more of the higher than lower PDGF-Rα + fibroblasts contained Ki67 (Ki67+), and Ki67+ fibroblasts predominated in the αSMA + but not the αSMA- population. By P12, Ki67+ fibroblasts comprised a minority in both the PDGF-Rα + and αSMA+ populations. At P4, most Ki67+ fibroblasts were PDGF-Rα + and αSMA- whereas at P12, most Ki67+ fibroblasts were PDGF-Rα- and αSMA-. More of the PDGF-Rα + than - fibroblasts contained αSMA at both P4 and P12. In the lung, proximate αSMA was more abundant around nuclei in cells expressing high than low levels of PDGF-Rα at both P4 and P12. Nuclear SMAD 2/3 declined from P4 to P12 in PDGF-Rα-, but not in PDGF-Rα + cells. In Mlg fibroblasts, αSMA mRNA increased after exposure to TGFβ, but declined after treatment with PDGF-A.</p> <p>Conclusion</p> <p>During both septal eruption (P4) and elongation (P12), alveolar PDGF-Rα may enhance the propensity of fibroblasts to transdifferentiate rather than directly stimulate αSMA, which preferentially localizes to non-proliferating fibroblasts. In accordance, PDGF-Rα more dominantly influences fibroblast proliferation at P4 than at P12. In the lung, TGFβ may overshadow the antagonistic effects of PDGF-A/PDGF-Rα signaling, enhancing αSMA-abundance in PDGF-Rα-expressing fibroblasts.</p

GR-891: a novel 5-fluorouracil acyclonucleoside prodrug for differentiation therapy in rhabdomyosarcoma cells

Differentiation therapy provides an alternative treatment of cancer that overcomes the undesirable effects of classical chemotherapy, i.e. cytotoxicity and resistance to drugs. This new approach to cancer therapy focuses on the development of specific agents designed to selectively engage the process of terminal differentiation, leading to the elimination of tumorigenic cells and recovery of normal cell homeostasis. A series of new anti-cancer pyrimidine acyclonucleoside-like compounds were designed and synthesized by structural modifications of 5-fluorouracil, a drug which causes considerable cell toxicity and morbidity, and we evaluated their applicability for differentiation therapy in human rhabdomyosarcoma cells. We tested the pyrimidine derivative GR-891, (RS)-1-{[3-(2-hydroxyethoxy)-1-isopropoxy]propyl}-5-fluorouracil, an active drug which shows low toxicity in vivo and releases acrolein which is an aldehyde with anti-tumour activity. Both GR-891 and 5-fluorouracil caused time- and dose-dependent growth inhibition in vitro; however, GR-891 showed no cytotoxicity at low doses (22.5 μmol l−1 and 45 μmol l−1) and induced terminal myogenic differentiation in RD cells (a rhabdomyosarcoma cell line) treated for 6 days. Changes in morphological features and in protein organization indicated re-entry in the pathway of muscular maturation. Moreover, GR-891 increased adhesion capability mediated by the expression of fibronectin, and did not induce overexpression of P-glycoprotein, the mdr1 gene product, implicated in multidrug resistance. New acyclonucleoside-like compounds such as GR-891 have important potential advantages over 5-fluorouracil because of their lower toxicity and their ability to induce myogenic differentiation in rhabdomyosarcoma cells. Our results suggest that this drug may be useful for differentiation therapy in this type of tumour. 1999 Cancer Research Campaig