Lantana (Lantana camara L.) biocontrol agents in Australia with possible options for India and Sri Lanka

The focus of this short article is the biocontrol agents of the globally-important species - lantana (Lantana camara L.), which was introduced as an ornamental plant during the 18th and 19th Centuries across continents. Lantana is now naturalized in most continents and causing problems in human-modified landscapes and is also spreading fast into conservation areas and forests. Currently, where it needs to be controlled, a variety of methods are available, which include manual, mechanical and chemical control, as well as fire. However, none of these methods, even when applied in combinations (integrated) have been sufficiently effective on a landscape level or can be sustainably applied to control large and dense infestations. It appears that future lantana management must be oriented towards re-investing in biocontrol simply because it is not feasible to control lantana over the long term using conventional methods. Numerous biocontrol agents have shown considerable promise but have not been well utilized in countries that have increased risks of further spread. Efforts to manage lantana in Australia are still continuing, with a well-developed National framework, an integrated approach and investment in additional biocontrol agents. South-Asian countries, especially India and Sri Lanka, can certainly benefit from Australian experiences in lantana management and R&D investments in biological control. This is especially so since research on host specificity and the effectiveness of agents would have already been conducted. This would require that both countries, and also, possibly some African countries, re-appraise the risks of lantana and make an increased effort at biocontrol to manage those risks, especially in natural ecosystems and conservation areas, heavily disturbed by tourism activities

Relations of science students’ academic performance at university level with their gender: a case study at the faculty of science, university of Peradeniya, Sri Lanka

University is an institution for higher education, research, and social development. Hence, the students’ performance at the University is very important as graduates are supposed to become future leaders in this world. There are many factors affecting the students’ performance at the University level. Thus, this study was focusing on assessing the impact of gender on students’ academic performance at University level. This is a quantitative study. Sample of the study was drawn from the Faculty of Science, University of Peradeniya through convenient sampling technique. The sample consisted of 1729 undergraduates from four consecutive batches from 2006 to 2009. There were 822 males and 907 females in the sample. The data were collected through documents from the Faculty of Science, University of Peradeniya and analyzed using MS Excel 2010 and SPSS 17. The study established a relationship between gender of students and their performance measured according to the students’ Grade Point Average (GPA) at the University. The results of the study revealed that the performance of female students is higher than that of males. There were 18% of female undergraduates in 4.00-3.70 GPA range while only 5% of male undergraduates were in the same range. Male undergraduates are prominent in 3.30-3.00 GPA range and < 3.00 GPA.This situation could be due to many inter-related factors such as study habits, aspirations, self-concepts, motivation, other psychological conditions, and some physiological aspects. Thus, an in-depth study has to be conducted to investigate the issue in order to support especially the male students to perform well in their higher education at the University level

Using cognitive decision models to prioritize E-mails

Michael D. Lee, Lama H. Chandrasena and Daniel J. Navarrohttp://csjarchive.cogsci.rpi.edu/Proceedings/2002/CogSci02.pd

In Vitro Evaluation of the Antagonistic Effect of Some Native Trichoderma Strains Against Economically Important Foliar Pathogens of Rubber

Rubber plants are subjected to serious fungal diseases and among them, the losses caused byfoliar diseases play an important role. The frequent use of chemical fungicides to controlcausative pathogens leads to environmental pollution, hazardous to human and may lead tothe development of new chemical resist pathogenic strains. Trichoderma species areubiquitous soil-borne Ascomycetes noted for their biocontrol capabilities against manyeconomically important plant pathogens. Hence, an attempt was made to investigate theantagonistic effect of some native Trichoderma isolates on the plant pathogenic fungi;Colletotrichum sp., Corynespora cassiicola, Phytophthora sp. and Drechslera heveae. Foliarpathogens were isolated from Rubber Research Institute, Dartonfield, Agalawaththa andidentified based on the symptoms, cultural and reproductive characteristics. FiveTrichoderma isolates isolated from different habitats in Sri Lanka were tested in vitro fortheir antagonistic effects against the four foliar pathogens. The results obtained from dualculture tests showed that all the five Trichoderma isolates effectively checked the growth ofthe four foliar pathogens. The test antagonists grew faster than the pathogen limiting theirgrowth. Trichoderma isolate A was the best antagonist against Drechslera heveae,Corynespora cassiicola and Colletotrichum sp. showing inhibition of 75.63%, 51.34% and74.46% respectively. Isolate B showed the best inhibition (70.99%) against Phytophthora sp.All antagonists showed their lowest inhibition against D. heveae. In conclusion, all the testedTrichoderma isolates showed antagonistic effect on the four foliar pathogens underinvestigation. Therefore, the fungal isolates under investigation can be used for furthergreenhouse and field studies to confirm the feasibility of using for the management of rubberfoliar pathogens.Keywords: Trichoderma spp., Drechslera heveae, Corynespora cassiicola, Colletotrichumspp., Phytopthora spp, Bio-control agent

Evaluation of pigeonpea accessions and selected lines for reaction to Maruca

Maruca vitrata (Geyer) is a serious insect pest of tropical legumes. In Sri Lanka, yield losses due to Maruca damage in pigeonpea [Cajanus cajan (L.) Millsp.] range up to 100%. The development of resistant cultivars and germplasm is one of the best means of control. The objectives of this study were to screen 271 accessions for resistance to M. vitrata and evaluate reaction of lines selected from the promising accessions. The high level of natural incidence of Maruca in Sri Lanka provided an opportunity for evaluation of germplasm at Field Crops Research and Development Institute, Maha Illuppallama. Screening of the germplasm accessions revealed large variation in Maruca damage to flowers and pods. On average, the Maruca damage in determinate accessions (66–75%) was higher than that of nondeterminate accessions (41–50%). Resistant plants from four determinate and 12 nondeterminate accessions were selected. Further selection for resistance to Maruca damage among and within lines derived from the resistant plants was exercised for six generations under nonsprayed field conditions. Under insecticide-free conditions, the selections from two accessions showed significant yield advantages over controls. Data on pod damage and larval counts indicated that the resistance was conditioned through yield compensation mechanisms. In pigeonpea, this is the first report of the selection of Maruca resistant lines. Further studies showed that by using the resistant genotypes it is possible to reduce the number of insecticide sprays for economic yields

Inter-Layer Coupling Induced Bandgap Reduction in Ultrathin MoS2

We report on a study of highly crystalline islands of MoS2 grown on HOPG substrate. Using STM/STS we find that the valence band edge shifts as a function of the layer number. Numerical calculations reveal the mechanism underlying the bandgap reduction and the role of the interfacial Sulfur atoms is clarified

The catatonic dilemma expanded

Catatonia is a common syndrome that was first described in the literature by Karl Kahlbaum in 1874. The literature is still developing and remains unclear on many issues, especially classification, diagnosis, and pathophysiology. Clinicians caring for psychiatric patients with catatonic syndromes continue to face many dilemmas in diagnosis and treatment. We discuss many of the common problems encountered in the care of a catatonic patient, and discuss each problem with a review of the literature. Focus is on practical aspects of classification, epidemiology, differential diagnosis, treatment, medical comorbidity, cognition, emotion, prognosis, and areas for future research in catatonic syndromes

Critical Invasion Science: Weeds, Pests, and Aliens

The study of invasive plants and animals calls strongly for a critical approach due to the deeply social nature of invasion landscapes, the power relations affecting the science of invasions, and the differential impacts of weed or pest control on lives and landscapes. I first explore what a “critical” invasion science means. Then I investigate several aspects of invasion science ripe for critical analysis: the history of the science (to understand what the science is doing and why), the terminology and categories of analysis, and the highly contested social, political, and ethical context within which invasion management takes place. I conclude with four proposals for further work in critical invasion science and examples of the types of questions it might ask