329 research outputs found
Profiling of Glycan Receptors for Minute Virus of Mice in Permissive Cell Lines Towards Understanding the Mechanism of Cell Recognition
The recognition of sialic acids by two strains of minute virus of mice (MVM), MVMp (prototype) and MVMi (immunosuppressive), is an essential requirement for successful infection. To understand the potential for recognition of different modifications of sialic acid by MVM, three types of capsids, virus-like particles, wild type empty (no DNA) capsids, and DNA packaged virions, were screened on a sialylated glycan microarray (SGM). Both viruses demonstrated a preference for binding to 9-O-methylated sialic acid derivatives, while MVMp showed additional binding to 9-O-acetylated and 9-O-lactoylated sialic acid derivatives, indicating recognition differences. The glycans recognized contained a type-2 Galβ1-4GlcNAc motif (Neu5Acα2-3Galβ1-4GlcNAc or 3′SIA-LN) and were biantennary complex-type N-glycans with the exception of one. To correlate the recognition of the 3′SIA-LN glycan motif as well as the biantennary structures to their natural expression in cell lines permissive for MVMp, MVMi, or both strains, the N- and O-glycans, and polar glycolipids present in three cell lines used for in vitro studies, A9 fibroblasts, EL4 T lymphocytes, and the SV40 transformed NB324K cells, were analyzed by MALDI-TOF/TOF mass spectrometry. The cells showed an abundance of the sialylated glycan motifs recognized by the viruses in the SGM and previous glycan microarrays supporting their role in cellular recognition by MVM. Significantly, the NB324K showed fucosylation at the non-reducing end of their biantennary glycans, suggesting that recognition of these cells is possibly mediated by the Lewis X motif as in 3′SIA-LeX identified in a previous glycan microarray screen
Prescribed Burning Based on Range Condition in the Okavango Delta Ramsar Site in Botswana, Africa
Governors and directors: Competing models of corporate governance
Why do we use the term ‘corporate governance’ rather than ‘corporate direction’? Early British joint stock companies were normally managed by a single ‘governor’. The ‘court of governors’ or ‘board of directors’ emerged slowly as the ruling body for companies. By the nineteenth century, however, companies were typically run by directors while not-for-profit entities such as hospitals, schools and charitable bodies had governors. The nineteenth century saw steady refinement of the roles of company directors, often in response to corporate scandals, with a gradual change from the notion of the director as a ‘representative shareholder’ to the directors being seen collectively as ‘representatives of the shareholders’. Governors in not-for-profit entities, however, were regarded as having broader responsibilities. The term ‘governance’ itself suggests that corporate boards should be studied as ‘political’ entities rather than merely through economic lenses such as agency theory
Determinants of flammability in savanna grass species
1. Tropical grasses fuel the majority of fires on Earth. In fire-prone landscapes, enhanced flammabil-ity may be adaptive for grasses via the maintenance of an open canopy and an increase in spa-tiotemporal opportunities for recruitment and regeneration. In addit ion, by burning intensely butbriefly, high flammability may protect resprouting buds from lethal temperatures. Despite thesepotential benefits of high flammability to fire-prone grasses, variation in flammability among grassspecies, and how trait differences underpin this variation, remains unknown.2. By burning leaves and plant parts, we experimentally determined how five plant traits (biomassquantity, biomass density, biomass moisture content, leaf surface-area-to-volume ratio and leaf effec-tive heat of combustion) combined to determine the three components of flammability (ignitability,sustainability and combustibility) at the leaf and plant scales in 25 grass species of fire-pr one SouthAfrican grasslands at a time of peak fire occurrence. The influence of evolutionary history onflammability was assessed based on a phylogeny built here for the study species.3. Grass speci es differed significantly in all components of flammability. Accounting for evolution-ary history helped to explain patterns in leaf-scale combustibility and sustainability. The five mea-sured plant traits predicted components of flammability, particularly leaf ignitability and plantcombustibility in which 70% and 58% of variation, respectively, could be explained by a combina-tion of the traits. Total above-ground biomass was a key drive r o f combustibility and sustainabi litywith high biomass species burning more intensely and for longer, and producing the highest pre-dicted fire spread rates. Moisture content was the main influence on ignitability, where speci es withhigher moisture conten ts took longer to ignite and once alight burnt at a slower rate. Bioma ss den-sity, leaf surface-area-to-volume ratio and leaf effective heat of combustion were weaker predictorsof flammability components.4. Synthesis. We demonstrate that grass flammability is predicted from easily measurable plant func-tional traits and is influenced by evolutionary history with some components showing phylogeneticsignal. Grasses are not homogenous fuels to fire. Rather, species differ in functional traits that inturn demonstrably influence flammability. This diver sity is consistent with the idea that flammabilitymay be an adaptive trait for grasses of fire-prone ecosystems
Victimisation in the lives of lesbian-identified women in South Africa : implications for clinical assessment and treatment
Few clinical studies have examined victimisation in the lives of lesbian women in South Africa and whether there are distinct implications for psychological treatment. This paper presents the assessment and treatment of a lesbian-identified South African survivor of childhood sexual abuse who, as an adult, was raped and later gang raped. Her victimisation in adulthood represented ‘corrective rape’ motivated by the prejudiced assumption that the sexuality of lesbian women is pathological and should be ‘corrected’ through rape. This paper lends insights into the role of heterosexism in shaping vulnerability to victimisation and the process of recovery. It provides recommendations for work with sexual minority clients and highlights the implications when there is an absence of safety and support in the external environment
Prepared to study: resources designed to aid student studies in human cadaveric anatomy
Purpose: The use of human cadaveric specimens for effective teaching of clinical human anatomy is well documented1. However, the study of cadaveric human anatomy typically occurs early in the undergraduate curricula for most health professional degree programs and can be an intimidating method of study2.
Methods: This paper describes preliminary studies into the design and development of a set of resources aimed to assist students in their preparation for, and study with, human cadaveric materials. Students in first year rehabilitation sciences (n=287) and speech pathology (n=43) in 2015 were provided with cadaveric-based resources prior to cadaveric practical classes. Student satisfaction, experience and competencies in anatomy were then assessed and compared to 2014 data from students who did not receive preparatory resources.
Results and Conclusion: Academic results from two student cohorts (Occupational Therapy and Speech Pathology) increased significantly from 2014, and particularly in association with practical examination components (spot test results). Student feedback and focus group data showed that students felt better equipped and supported through the cadaveric study classes and believed themselves better prepared for self-study3. The teaching and learning strategies applied here have lead to demonstrated improvement in the study of anatomy and an enhanced student learning experience
Force-molting of hens and all-night lighting as factors in egg production
Cover title. "April 1934. (Reprinted 1937)" Includes bibliographical references (p. 7). Also available in microfilm under: State agricultural papers
Simplified rations for farm chickens
Cover title. "June 1934 (Reprinted August 1936)." Also available in microfilm under: State agricultural papers
Anthony Trollope's son in Australia: The life and letters of F.J.A. Trollope (1847-1910)
No abstract availabl
Facilitation or Competition? Tree Effects on Grass Biomass across a Precipitation Gradient
Savanna ecosystems are dominated by two distinct plant life forms, grasses and trees, but the interactions between them are poorly understood. Here, we quantified the effects of isolated savanna trees on grass biomass as a function of distance from the base of the tree and tree height, across a precipitation gradient in the Kruger National Park, South Africa. Our results suggest that mean annual precipitation (MAP) mediates the nature of tree-grass interactions in these ecosystems, with the impact of trees on grass biomass shifting qualitatively between 550 and 737 mm MAP. Tree effects on grass biomass were facilitative in drier sites (MAP≤550 mm), with higher grass biomass observed beneath tree canopies than outside. In contrast, at the wettest site (MAP = 737 mm), grass biomass did not differ significantly beneath and outside tree canopies. Within this overall precipitation-driven pattern, tree height had positive effect on sub-canopy grass biomass at some sites, but these effects were weak and not consistent across the rainfall gradient. For a more synthetic understanding of tree-grass interactions in savannas, future studies should focus on isolating the different mechanisms by which trees influence grass biomass, both positively and negatively, and elucidate how their relative strengths change over broad environmental gradients. © 2013 Moustakas et al
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