857 research outputs found
Ergot: A New Disease Threat to Sorghum in the Americas and Australia
Sorghum, Sorghum bicolor (L.) Moench, is the world’s fifth most important cereal crop, cultivated on about 45 million hectares for food, feed, beverage, and fodder. The most significant technological change since the 1960s has been the development and use of F1 hybrid seed (14), which has lead to a dramatic
improvement in the crop’s productivity. Sorghum cultivation in intensive, commercialized systems where yields average 3 to 5 t ha-1 relies almost totally on hybrid seed. In contrast, yields vary widely and average less than 1 t ha-1 in low-input production systems
Multi-Informant Predictors of Social Inclusion for Students with Autism Spectrum Disorders Attending Mainstream School
This study examined differential profiles of behavioural characteristics predictive of successful inclusion in mainstream education for children with autism spectrum disorders (ASD) and comparison students. Multiple regression analyses using behavioural ratings from parents, teachers and peers found some evidence for differential profiles predicting peer acceptance and rejection. High levels of peer-rated shyness significantly predicted social rejection in comparison students only. Parent-rated prosocial behaviour also differentially predicted social acceptance; high-levels of prosocial behaviour predicted acceptance in comparison students, but low-levels were predictive for students with ASD. These findings suggest that schools may seek to augment traditional social skills programmes with awareness raising about ASD among mainstream pupils to utilise peers’ apparent willingness to discount characteristics such as ‘shyness’
Ergot - a Global Threat to Sorghum
The current status of ergot (Claviceps sorghi and C. africana) of sorghum is reviewed. The biology, epidemiology, control, host plant resistance and integrated management strategies of the disease are discussed
Can developmental cognitive neuroscience inform intervention for social, emotional and behavioural difficulties (SEBD)?
An initial evaluation of the utility of designing an intervention to address neuroscience-based subtyping of children who have conduct problems was undertaken in this pilot study. Drawing on the literature on callous–unemotional traits, a novel intervention programme, ‘Let's Get Smart’, was implemented in a school for children with social emotional and behavioural difficulties. A mixed-methods design was used to investigate the perspectives of staff participant-observers in the change process, alongside standardised scores on measures of pupil performance and behaviour. Both qualitative and quantitative results showed reductions in externalising behaviour and improvements in measures of hypothesised underlying cognitive and affective processes. While externalising behaviour improved across subtypes, associated changes in underlying processes differed by subtype, supporting the potential value of neuroscience-informed contributions to intervention planning
A Disease of Pearl Millet in Zimbabwe Caused by Pantoea agglomerans
Necrosis at the leaf tips and margins of pearl millet (Pennisetum glaucum (L.) R. Br.) was observed in 1995 in a Pseudomonas syringae resistance screening nursery near Bulawayo, Zimbabwe. Straw-colored lesions with a chlorotic edge often extended the leaf length, and were atypical of the round spots, with a brown margin, caused by P. syringae (1). Bacteria were isolated from cut lesions macerated in water by dilution streaking onto King's medium B and nutrient agar. A gram-negative, nonfluorescent, fermentative, rod-shaped bacterium, forming yellow colonies on nutrient agar was consistently observed. Three pots of 10, 2-to 3-week-old seedlings of a susceptible cultivar, 852B, were inoculated with a 108 CFU per ml suspension from cultures by misting or injection into the whorl. In three experiments, the treatment and uninoculated control were incubated at 25°C and 95% relative humidity for 48 h before transfer to the greenhouse. The original symptoms of watersoaking at leaf tips and margins were observed after 4 days. Necrotic lesions surrounded by chlorotic tissue were observed a day later. Fluorescence on King's medium B, and levan, oxidase, potato-rot, arginine dihydrolase, 2-keto gluconate, nitrate reduction, gelatin, phenylalanine deaminase, and acid from starch tests were negative. Tobacco hypersensitivity, acid from sucrose and glycerol, aesculin hydrolysis, lipase, indole production, and growth on tetrazolium chloride were positive. The identification of the pathogen to the species level as Pantoea agglomerans (Ewing and Fife 1972) Gavini et al. 1989, formerly Erwinia herbicola, was by fatty acid analysis by the International Mycological Institute (Egham, Surrey, UK). P. agglomerans was recorded as a pathogen of pearl millet in India in 1958 (2)
Approximation algorithms for general cluster routing problem
Graph routing problems have been investigated extensively in operations
research, computer science and engineering due to their ubiquity and vast
applications. In this paper, we study constant approximation algorithms for
some variations of the general cluster routing problem. In this problem, we are
given an edge-weighted complete undirected graph whose vertex set
is partitioned into clusters We are also given a subset
of and a subset of The weight function satisfies the
triangle inequality. The goal is to find a minimum cost walk that visits
each vertex in only once, traverses every edge in at least once and
for every all vertices of are traversed consecutively.Comment: In COCOON 202
A new species complex including Claviceps fusiformis and Claviceps hirtella
Isolates of Claviceps species with lunate to fusiform macroconidia were collected from panicoid grasses in Texas and
Zimbabwe and described as new species based on anamorphs since no teleomorphs were available. Characterization
was based upon morphology and partial sequences of rDNA and β-tubulin. The isolates grouped into two stronglysupported
clades. The first clade contained ancestral C. hirtella and C. fusiformis from pearl millet (Pennisetum
glaucum) in clade terminal position with Texas isolates from native cup grass (Eriochloa sericea) and pearl millet
grouped between them. The second clade consisted of African isolates from Urochloa and Eragrostis. The isolates from
Texas from pearl millet and buffel grass (Cenchrus ciliaris) and isolates from E. sericea were described as new species,
Sphacelia texensis and Sphacelia eriochloae, respectively. Both species had morphology, DNA markers, and alkaloid
production that was intermediate between those features exhibited in C. fusiformis and C. hirtella. The African isolates
from Urochloa and Eragrostis were also described as a new species, Sphacelia lovelessii. In shaken cultures, C. hirtella
readily produced a whole range of clavines with agroclavine and festuclavine predominating, but ergometrine was also
detected. Claviceps fusiformis produced mainly agroclavine and elymoclavine, S. eriochloae produced mainly
agroclavine, elymoclavin and festuclavine and the cultures of S. texensis contained small amounts of agroclavine and
festuclavine. Only traces of clavines were found in cultures of S. lovelessii of the second clade. The alkaloid content of
infected florets in the sphacelial (honeydew) developmental stage was also measured. Only C. fusiformis and S.
eriochloae produced alkaloids in planta at this early stage
New Claviceps species from warm-season grasses
Eight undescribed species of Claviceps were recognized from the combinations of molecular and morphological characters. The teleomorph was observed only for Claviceps setariicola. Phylogenetic affinities of the new species inside the genus were revealed by a 5.8S-ITS-28S nrDNA analysis. Claviceps chloridicola, C. tenuispora, C. setariicola and C. setariiphila are related to C. maximensis; C. truncatispora is a sister species to C. pusilla. Claviceps clavispora and C. langdonii cluster with species colonizing maize and sorghum. The position of C. loudetiae is unclear. Comparisons with herbarium specimens showed C. setariicola as a well-established species on Setaria spp. in the southern USA. C. tenuispora was recorded on Cenchrus and Pennisetum in Brazil, USA, and Zimbabwe. C. setariiphila was found on S. geniculata in Brazil. C. chloridicola, C. loudetiae and C. truncatispora occurred in African savannas on Chloris, Loudetia, and Hyparrhenia spp., respectively. C. clavispora was found on Paspalum sp. and Urochloa sp. in Mexico and C. langdonii colonized Dichanthium spp. in the southern USA and probably in Mexico. The occurrence of C. pusilla on pearl millet in the USA (Texas) is reported and the record of C. sulcata on Urochloa brizantha in Brazil is confirmed by nrDNA sequence comparison with an African herbarium specimen. No alkaloids were detected in sclerotia and/or sphacelia of the new species
- …