Biology and resource acquisition of mistletoes, and the defense responses of host plants

Background Mistletoes are the most successful group of obligatory hemi-parasitic flowering plants that attach to the host via haustorium for obtaining water and minerals. This review aims to assess the current knowledge on mistletoes host plant recognition, haustorium formation, water/minerals acquisition, and host plants’ defense signaling and responses against mistletoe attack. Results Some mistletoes are host-specific while others are generalists occurring on a wide range of vascular plants. The host nitrogen (N) content, parasite–host chemical interactions, compatibility, and dispersal agents are the main determinant factors for host specificity. Mistletoes take up substantial amounts of water and minerals passively via apoplastic routes, and most are xylem feeders, but could shift to phloem-feeding during the physiological stress of the host plants. Current evidence highlighted that cell wall loosening and modification are critical during the development of the haustorium in the host tissue. This is made possible by the application of physical pressures by the developing haustorium and cell wall degradation using enzymes (xyloglucan endotransglycosylases, glucanase, expansins, etc.) produced by the mistletoe. Host plants defend against mistletoe infection mechanically by producing spines, lignin, suberin, etc., which discourages dispersers, and chemically defend by killing the infector or inhibiting the establishment of the haustorium using their secondary metabolites such as terpenes, phenolics, and N-containing compounds. Although the host plants' response to mistletoe attack resembles the response to other biotic stresses, unlike short-term stressors, the effect of mistletoe attack is long-term and depends on the parasite load. Infection by mistletoe leads to water and nutrient stress of the host plant and deteriorates its healthy establishment and survival. Conclusion Mistletoes are heterogeneous group in the order Santalales which have versatile mechanisms for pollination, seed dispersal and nutrient acquisition from host plants. Infection by mistletoes triggers host plant responses, varying from mechanical to chemical mechanisms which are analogous to herbivory defences, and negatively impacts host plant growth and reproduction

Child labor and childhood behavioral and mental health problems in Ethiopia

Background: According to ILO estimates, at least 180 million children aged 5 to 14 years are currently engaged in fulltime work in the developing countries. However, very little information exists about childhood behavioral and mental disorders in Ethiopia. Objective: The objectives of this study are to estimate the prevalence and describe the nature of behavioral and mental health problems, as well as child abuse, nutritional problems, gross physical illness and injury among child laborers aged 8 to 15 years in Ethiopia. However, only the behavioral and mental health problems of the study population are examined here. Methods: A cross-sectional survey of children aged 8 to 15 years, and who were engaged in fulltime work in different formal and informal sectors non-laborers, was conducted in four major towns of Ethiopia. The screening instrument known as Reported Questionnaire on Children (RQC) and a diagnostic instrument known as the Diagnostic Interview for Children and Adolescents ( DICA) were used to detect symptoms and signs of behavioral and mental problems in the children. br> Results: A total of 2000 child laborers and 400 non-laborers were interviewed using RQC to screen for probable cases of behavioral and mental problems. Of these, 50% of the laborers and 42% of the non-laborers were males. The mean age of the laborers was 13.8 ±1.8 years while that of the non-laborers was 12.2 ±2.1 years. More females (76.8%) were found to have been engaged in domestic labor than males. The RQC interview screened 9.4% (n=226) of the children as probable cases of mental/ behavioral disorders, (14.0% non-laborers and 8.5% laborers). The second stage DICA interview gave an overall prevalence of 5.5% (4.9% in laborers and 8.8% in non-laborers). Conclusion: The prevalence of childhood behavioral and mental disorders in this study is within the range reported in previews studies conducted on children of the same age group. However, the lower prevalence of childhood disorders in the child laborers compared to that of the non-laborers found in the current study is probably due to selection bias or healthy workers effect. Thus, further study is recommended to explain this unexpected finding. The Ethiopian Journal of Health Development Vol. 20 (2) 2006: 119-12

Deep Tillage Improves Degraded Soils in the (Sub) Humid Ethiopian Highlands

Intensification of rainfed agriculture in the Ethiopian highlands has resulted in soil degradation and hardpan formation, which has reduced rooting depth, decreased deep percolation, and increased direct runoff and sediment transport. The main objective of this study was to assess the potential impact of subsoiling on surface runoff, sediment loss, soil water content, infiltration rate, and maize yield. Three tillage treatments were replicated at five locations: (i) no tillage (zero tillage), (ii) conventional tillage (ox-driven Maresha plow, up to a depth of 15 cm), and (iii) manual deep ripping of the soil’s restrictive layers down to a depth of 60 cm (deep till). Results show that the posttreatment bulk density and penetration resistance of deep tillage was significantly less than in the traditional tillage and zero-tillage systems. In addition, the posttreatment infiltration rate for deep tillage was significantly greater, which resulted in significantly smaller runoff and sedimentation rates compared to conventional tillage and zero tillage. Maize yields were improved by 6% under deep tillage compared to conventional tillage and by 29% compared to no tillage. Overall, our findings show that deep tillage can be effective in overcoming some of the detrimental effects of hardpans in degraded soils

The SASSCAL contribution to climate observation, climate data management and data rescue in Southern Africa

A major task of the newly established "Southern African Science Service Centre for Climate Change and Adaptive Land Management" (SASSCAL; www.sasscal.org) and its partners is to provide science-based environmental information and knowledge which includes the provision of consistent and reliable climate data for Southern Africa. Hence, SASSCAL, in close cooperation with the national weather authorities of Angola, Botswana, Germany and Zambia as well as partner institutions in Namibia and South Africa, supports the extension of the regional meteorological observation network and the improvement of the climate archives at national level. With the ongoing rehabilitation of existing weather stations and the new installation of fully automated weather stations (AWS), altogether 105 AWS currently provide a set of climate variables at 15, 30 and 60 min intervals respectively. These records are made available through the SASSCAL WeatherNet, an online platform providing near-real time data as well as various statistics and graphics, all in open access. This effort is complemented by the harmonization and improvement of climate data management concepts at the national weather authorities, capacity building activities and an extension of the data bases with historical climate data which are still available from different sources. These activities are performed through cooperation between regional and German institutions and will provide important information for climate service related activities

COVID-19 lockdown and natural resources: a global assessment on the challenges, opportunities, and the way forward

Background: The Coronavirus (COVID-19) is a global pandemic caused by SARS-CoV-2, which has an enormous effect on human lives and the global environment. This review aimed to assess the global scientific evidence on the impact of COVID-19 lockdown on natural resources using international databases and search engines. Thus, the unprecedented anthropause due to COVID-19 has positive and negative effects on natural resources. Main body This review showed that the unprecedented pandemic lockdown events brought a negative impact on the physical environment, including pollution associated with a drastic increase in person protective equipment, deforestation, illegal poaching and logging, overfishing, disruption of the conservation program and projects. It is noted that the spread of pandemic diseases could be aggravated by environmental pollution and a rapid increase in the global population. Despite these negative impacts of COVID-19, the anthropause appear to have also several positive effects on natural resources such as short term reduction of indoor and outdoor environmental pollutants (PM2.5, PM10, NO2, SO2, CO, and CO2), reduction in noise pollutions from ships, boats, vehicles, and planes which have positive effects on aquatic ecosystems, water quality, birds behaviour, wildlife biodiversity, and ecosystem restoration. Conclusion Therefore, governments and scientific communities across the globe have called for a green recovery to COVID-19 and implement multi-actor interventions and environmentally friendly technologies to improve and safeguard sustainable environmental and biodiversity management and halt the next pandemic

Social Value Creation in Institutional Voids: A Business Model Perspective

The literature on Base of the Pyramid (BoP) strategies emphasizes that creating social value requires collaborative, multi-stakeholder business approaches. However, there is limited understanding of how businesses can successfully coordinate such value creation processes in the developing economies that face significant institutional voids. This study adopts a business model perspective for analyzing social value creation processes that span organizational boundaries. We introduce a novel, theoretically grounded business model framework that helps conceptualize social value by locating the various loci of value creation, and the stakeholders that partake in creating and capturing this value. We subsequently analyze the mechanisms of social value creation in M-Pesa, a renowned boundaryspanning mobile money system that has advanced financial inclusion among tens of millions of u

Social Value Creation in Institutional Voids: A Business Model Perspective

The literature on Base of the Pyramid (BoP) strategies emphasizes that creating social value requires collaborative, multi-stakeholder business approaches. However, there is limited understanding of how businesses can successfully coordinate such value creation processes in the developing economies that face significant institutional voids. This study adopts a business model perspective for analyzing social value creation processes that span organizational boundaries. We introduce a novel, theoretically grounded business model framework that helps conceptualize social value by locating the various loci of value creation, and the stakeholders that partake in creating and capturing this value. We subsequently analyze the mechanisms of social value creation in M-Pesa, a renowned boundary-spanning mobile money system that has advanced financial inclusion among tens of millions of users in Kenya. The results show that information and communications technology can help advance social value creation by reducing the cost of coordinating boundary-spanning business models that integrate diverse societal stakeholders. The results further point to uneven distributional outcomes in self-governing social value creation strategies where the focal firm plays a coordinating role

Retroperitoneal liposarcoma associated with small plaque parapsoriasis

<p>Abstract</p> <p>Background</p> <p>Extremely rare cases of paraneoplastic syndromes or ectopic production of proteins associated with liposarcoma are reported in literature. Production of Granulocyte-Colony Stimulating Factor, alpha-fetoprotein, paraneoplastic pemphigus and leucocytosis, Acrokeratosis paraneoplastica (Bazex's syndrome) are reported.</p> <p>The present report describes a case of retroperitoneal liposarcoma associated with small plaque parapsoriasis. Our search in the English literature of such a kind of association did not reveal any case reported.</p> <p>Case presentation</p> <p>A 74 year male patient was admitted to our hospital because of the presence of an abdominal mass in right iliac fossa. He also complained of a two-year history of psoriasiform eruptions. The CT scan showed a retroperitoneal pelvic mass. Therefore surgical resection of the tumor was performed. After surgery, the skin eruptions disappeared completely in seven days and so a diagnosis of parapsoriasis syndrome was done.</p> <p>Conclusion</p> <p>Parallel disappearing of skin eruptions after surgery, typical clinical picture and not specific histology of the cutaneous lesions suggest the diagnosis of small plaque parapsoriasis. Therefore we propose to add Small Plaque Parapsoriasis to the list of paraneoplastic syndromes associated to liposarcoma.</p