Biotechnology approaches to developing herbicide tolerance/selectivity in crops

The use of herbicides has revolutionized weed control in many crop production systems. However, with the increasing development of weed resistances to many popular selective herbicides, the need has arisen to rethink the application of chemical weed control. Approaches to maintain the efficiency of chemical weed control include the discovery of new herbicide target sites in plants and the discovery/ synthesis of new, more potent herbicidal molecules. However, these approaches are expensive to execute, take considerably long times to succeed and may lead to increased chemical loads in the environment. Since many existing broad-spectrum herbicides are still effective, an alternative strategy adopted to ensure the safe use of broad-spectrum herbicides in a wide range of crops is the application of biotechnological techniques to engineer crop selectivity to these herbicides. In this review we summarize efforts being made to develop crop herbicide selectivity using biotechnology.Keywords: Biotechnology, herbicide resistance, cell culture, mutagenesis, genetic transformatio

Evaluating LAB@FUTURE, a collaborative e-learning Laboratory experiments platform

This paper presents Lab@Future, an advanced e-learning platform that uses novel Information and Communication Technologies to support and expand laboratory teaching practices. For this purpose, Lab@Future uses real and computer generated objects that are interfaced using mechatronic systems, augmented reality, mobile technologies and 3D multi user environments. The main aim is to develop and demonstrate technological support for practical experiments in the following focused disciplines namely: Fluid Dynamics - Science subject in Germany, Geometry - Mathematics subject in Austria, History and Environmental Awareness – Arts and Humanities subjects in Greece and Slovenia. In order to pedagogically enhance the design and functional aspects of this e-learning technology, we are investigating the dialogical operationalisation of learning theories so as to leverage our understanding of teaching and learning practices in the targeted context of deployment. To be able to evaluate the lab@future system in its entire complexity an evaluation methodology including several phases has been developed, performing formative as well as summative evaluations

Solar photovoltaic energy progress in Zambia : a review

Abstract: Regionally, Southern Africa is facing many challenges with regard to the level of access to energy. The situation is most compounded in the rural areas where poverty and lack of development are taking place at a snail pace. In order to achieve and promote sustainable development, the use of solar energy has been regarded by the government of Zambia and the sub-Saharan African region as the best alternative to the current energy deficit that the region is facing. To begin with, the government of Zambia, in the last decade, has supported solar photovoltaic energy research and development. However, the country has had challenges with achieving the set targets of connecting 10,000 new household by 2013 and ended up reducing the target to 2500 households of which 500 household of the proposed target was connected in 2015. This review is a desktop study of the on-going research on the solar energy and policy analysis of Zambia. It reviews the current solar photovoltaic and renewable energy trends in Zambia based on secondary data collected from various literatures, reports, and local contacts. The paper also highlights some of the solar energy achievements and failures in Zambia such as the 50MW solar mini-grid with the lowest tariff of US$0.0602 unit per kilowatt-hour and as well as the efforts, the government of Zambia has made through the help of international donors and the World Bank to scale up initiatives. Finally, it has also discussed the Zambian government policies and initiatives to promote deployment of solar energy technologies in the country. The review of solar photovoltaic energy is vital, as it will help the decision makers and various stakeholders to understand the current renewable status, barriers and challenges in Zambia and find alternative ways to overcome these challenges and barriers

Influence of Principals’ Instructional Supervision Practices on Kenya Certificate of Secondary Education (KCSE) Performance in Public Secondary Schools in Makueni County, Kenya

KCSE Performance in Public secondary schools in Makueni County, Kenya has consistently declined between 2014 and 2018. Although no empirical studies have explained the cause of the decline, Principals’ instructional supervision practices may have contributed to the trend necessitating the need for an investigation. This study investigated Influence of Principals’ Instructional Supervision Practices on Kenya Certificate of Secondary Education (KCSE) Performance in Public Secondary Schools in Makueni County, Kenya. The objective of the study was to establish the influence of principals’ instructional supervision practices on KCSE performance in public secondary schools in Makueni County, Kenya. The hypothesis for the study was that there is no statistically significant relationship between principals’ instructional supervision practices and students’ performance in KCSE in public secondary schools in Makueni County, Kenya. The study employed mixed methods research design. The rationale for using the method is that it combines both qualitative and quantitative data within a single study hence complementing each other by integrating their strengths. The target population was all principals and teachers of public secondary schools in Makueni County. The study employed stratified sampling technique for schools, equal allocation sampling technique for both principals and teachers for quantitative phase while maximal variation sampling was used for qualitative phase. Means, percentage and frequencies were used to determine the distribution of variables under study among the respondents and represented in tables and figures. Pearson correlation coefficient was used to test the relationship between principals’ instructional supervision practices and KCSE performance in public secondary schools in Makueni County. The results for quantitative phase indicated that the coefficient of correlation (r) for the objective was 0.6 at significance level of 0.04. Principals interviewed attested that they embraced instructional supervision practices. The study concluded that principals of public secondary schools in Makueni County, Kenya applied effective instructional supervision practices that positively influenced KCSE performance and that  principals’  instructional supervision practices influence  students’ KCSE performance in public secondary schools in Makueni County .The study recommends that principals  be trained on specific instructional supervision strategies to enhance their effectiveness in instructional leadership. Keywords: Supervision, Instructional supervision, principals’ instructional supervision practices, Supervision practices DOI: 10.7176/JEP/11-15-14 Publication date:May 31st 202

Mycotoxins profiling of the culture material of Fusarium verticillioides (Sacc.) Nirenberg culture (CABI-IMI 392668) isolated from rice in Niger State, Nigeria...

Full Title: Mycotoxins profiling of the culture material of Fusarium verticillioides (Sacc.) Nirenberg culture (CABI-IMI 392668) isolated from rice in Niger State, Nigeria and its cytotoxic effects on human lymphocytes comparatively to those of some mycotoxin standardsAbstract: An extract of Fusarium verticillioides (Sacc.) Nirenberg culture isolated from rice in Niger State, Nigeria, previously found to be acutely toxic to mice and chicks was established to contain 8.233 ppm of total fumonisins (FBs). The present work was undertaken to evaluate the in vitro cytotoxic effect to human lymphocytes of the same 4-year old extract via flow cytometry over a 3 h period in comparison with those of aflatoxin B1 (AFB1), ochratoxin A (OTA) and fumonisin B1 (FB1) and to further elucidate the mycotoxins in extract using thin layer (TLC), column (CC) and high performance liquid chromatographic (HPLC) techniques. The efficiencies of different solvents for extraction of FBs were also determined. A dose-dependent response was obtained for all toxins tested via cytotoxicity assay. At concentrations of 25, 50 and 100 μg/ml, OTA was more toxic than AFB1 followed by the  extract which was comparatively as toxic as FB1. Cytotoxicity data also revealed that, apoptosis is the major form of cell death induced by the tested mycotoxins and extract. Fumonisins B1 (FB1), B2 (FB2) and B3 (FB3) were found in the fungal extract at concentrations of 16.302, 6.423 and 2.456 ppm, respectively. The results also demonstrated that FBs are not extractible in hexane, benzene, diethyl ether and ethyl acetate, very low amount of the toxins can be recovered using dichloromethane (5 to 7%) and acetone (<10%), while methanol, acetonitrile and their aqueous solutions (32 to 87%) were found to be the best FBs extraction solvents.Key words: Cytotoxicity, human lymphocytes, fumonisins, rice, Nigeria

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma

Purpose:To independently validate the performance of the University of North Carolina Optical Coherence Tomography (UNC OCT) Index in diagnosing and predicting early glaucoma. Methods:Data of 118 normal subjects (118 eyes) and 96 subjects (96 eyes) with early glaucoma defined as visual field mean deviation (MD) greater than -4 decibels (dB), aged 40 to 80 years, and who were enrolled in the Full-Threshold Testing Size III, V, VI comparison study were used in this study. CIRRUS OCT average and quadrants' retinal nerve fiber layer (RNFL); optic disc vertical cup-to-disc ratio (VCDR), cup-to-disc area ratio, and rim area; and average, minimum, and six sectoral ganglion cell-inner plexiform layer (GCIPL) measurements were run through the UNC OCT Index algorithm. Area under the receiver operating characteristic curve (AUC) and sensitivities at 95% and 99% specificity were calculated and compared between single parameters and the UNC OCT Index. Results:Mean age was 60.1 ± 11.0 years for normal subjects and 66.5 ± 8.1 years for glaucoma patients (P < 0.001). MD was 0.29 ± 1.04 dB and -1.30 ± 1.35 dB in normal and glaucomatous eyes (P < 0.001), respectively. The AUC of the UNC OCT Index was 0.96. The best single metrics when compared to the UNC OCT Index were VCDR (0.93, P = 0.054), average RNFL (0.92, P = 0.014), and minimum GCIPL (0.91, P = 0.009). The sensitivities at 95% and 99% specificity were 85.4% and 76.0% (UNC OCT Index), 71.9% and 62.5% (VCDR, all P < 0.001), 64.6% and 53.1% (average RNFL, all P < 0.001), and 66.7% and 58.3% (minimum GCIPL, all P < 0.001), respectively. Conclusions:The findings confirm that the UNC OCT Index may provide improved diagnostic perforce over that of single OCT parameters and may be a good tool for detection of early glaucoma. Translational Relevance:The UNC OCT Index algorithm may be incorporated easily into routine clinical practice and be useful for detecting early glaucoma

Validation of the UNC OCT Index for the Diagnosis of Early Glaucoma

Observations of binary stars containing an accreting black hole or neutron star often show x-ray emission extending to high energies (>10 kilo­–electron volts), which is ascribed to an accretion disk corona of energetic particles akin to those seen in the solar corona. Despite their ubiquity, the physical conditions in accretion disk coronae remain poorly constrained. Using simultaneous infrared, optical, x-ray, and radio observations of the Galactic black hole system V404 Cygni, showing a rapid synchrotron cooling event in its 2015 outburst, we present a precise 461 ± 12 gauss magnetic field measurement in the corona. This measurement is substantially lower than previous estimates for such systems, providing constraints on physical models of accretion physics in black hole and neutron star binary systems

Circular Economy: An Antidote to Municipal Solid Waste Challenges in Zambia

Zambia is one of the fastest developing countries in Africa. It is land linked and has one of the most urbanizing cities, the capital, Lusaka. The country is now grappling with serious challenges of managing municipal solid waste that is generated from its growing population and increased economic activity. Circular economy ensures that all the negativities of linear economy are reduced or prevented by ensuring reduced generation of waste at source, reuse of the generated waste and if these cannot be implemented, recycling of the generated waste follows. This results into environmental benefits such as clean and safe air and water. Land degradation or pollution is prevented. Therefore, there is need to implement circular economy as an antidote to the current municipal solid waste challenges. Municipal solid waste management is a critical public good that provides a barometer for the effectiveness of any governance system around the world. Successive governments should embed the waste management issue in all the policies developed for to ensure sustainability. In today’s world of material scarcity and a call to action toward climate change action, it cannot be over emphasized that circular economy is the antidote to municipal solid waste challenges Zambia is facing

Exploiting Click Chemistry for the Covalent Immobilization of Tetra (4-Propargyloxyphenoxy) Metallophthalocyanines onto Phenylazide-Grafted Gold Surfaces

In this study, tetra-(4-propargyloxy)phenoxy phthalocyanines (MTPrOPhOPc) were covalently immobilized as thin films onto gold surfaces via click reaction. The gold electrode surfaces were pre-functionalized with phenylazide (Au-PAz) thin film using in-situ diazonium generation followed by electrografting. Copper (I) catalyzed alkynyl-azide cycloaddition (CuCAAC) reaction was used to covalently immobilize the MTPrOPhOPcs onto the gold electrode surfaces to form Au-PAz-MTPrOPhOPc. The MTPrOPhOPcs were further studied for their electrocatalytic and electroanalytical properties towards the detection of hydrogen peroxide. Au-PAz-MTPrOPhOPc exhibited good reproducibility and stability in various electrolyte conditions. Electrochemical and spectroscopic surface characterization of the functionalized gold electrode surfaces confirmed the presence of the phenylazide and MTPrOPhOPc thin monolayer films. The excellent electroanalysis of hydrogen peroxide with the limit of detection (LoD) and limit of quantification (LoQ) in the μM range was obtained. The electrocatalytic reduction peaks for H2O2 were observed at −0.37 V for Au-PAz-Mn(OAc)TPrOPhOPc and −0.31 V for Au-PAz-CoTPrOPhOPc when Ag|AgCl pseudo-reference electrode was used. The Au-PAz-Mn(OAc)TPrOPhOPc and Au-PAz-CoTPrOPhOPc gold electrode surfaces showed good sensitivity and reproducibility towards the electrocatalytic reduction of hydrogen peroxide in pH 7.4 phosphate buffer solution

Early Clinical and Subclinical Visual Evoked Potential and Humphrey's Visual Field Defects in Cryptococcal Meningitis.

Cryptococcal induced visual loss is a devastating complication in survivors of cryptococcal meningitis (CM). Early detection is paramount in prevention and treatment. Subclinical optic nerve dysfunction in CM has not hitherto been investigated by electrophysiological means. We undertook a prospective study on 90 HIV sero-positive patients with culture confirmed CM. Seventy-four patients underwent visual evoked potential (VEP) testing and 47 patients underwent Humphrey's visual field (HVF) testing. Decreased best corrected visual acuity (BCVA) was detected in 46.5% of patients. VEP was abnormal in 51/74 (68.9%) right eyes and 50/74 (67.6%) left eyes. VEP P100 latency was the main abnormality with mean latency values of 118.9 (±16.5) ms and 119.8 (±15.7) ms for the right and left eyes respectively, mildly prolonged when compared to our laboratory references of 104 (±10) ms (p<0.001). Subclinical VEP abnormality was detected in 56.5% of normal eyes and constituted mostly latency abnormality. VEP amplitude was also significantly reduced in this cohort but minimally so in the visually unimpaired. HVF was abnormal in 36/47 (76.6%) right eyes and 32/45 (71.1%) left eyes. The predominant field defect was peripheral constriction with an enlarged blind spot suggesting the greater impact by raised intracranial pressure over that of optic neuritis. Whether this was due to papilloedema or a compartment syndrome is open to further investigation. Subclinical HVF abnormalities were minimal and therefore a poor screening test for early optic nerve dysfunction. However, early optic nerve dysfunction can be detected by testing of VEP P100 latency, which may precede the onset of visual loss in CM