10,009 research outputs found
Methods for nanoparticle labeling of ricin and effect on toxicity
The unique optical properties associated with nanostructured materials that support the excitation of surface plasmons offer many new opportunities for the enhanced optical investigation of biological materials that pose a security threat. In particular, ricin is considered a significant bioterrorism risk due to its high toxicity combined with its ready availability as a byproduct in castor oil production. Therefore, the development of optical techniques capable of rapid on-site toxin detection with high molecular specificity and sensitivity continues to be of significant importance. Furthermore, understanding of the ricin cell entry and intracellular pathways remains poor due to a lack of suitable bioanalytical techniques. Initial work aimed at simultaneously tackling both these issues is described where different approaches for the nanoparticle labeling of ricin are investigated along with changes in ricin toxicity associated with the labeling process
Role of Schizosaccharomyces pombe RecQ homolog recombination and checkpoint genes in UV Damage tolerance
The cellular responses to DNA damage are complex and include direct DNA repair pathways that remove the damage and indirect damage responses which allow cells to survive DNA damage that has not been, or cannot be, removed. We have identified the gene mutated in the rad12.502 strain as a Schizosaccharomyces pombe recQ homolog. The same gene (designated rqh1) is also mutated in the hus2.22 mutant. We show that Rqh1 is involved in a DNA damage survival mechanism which prevents cell death when UV-induced DNA damage cannot be removed. This pathway also requires the correct functioning of the recombination machinery and the six checkpoint tad gene products plus the Cds1 kinase. Our data suggest that Rqh1 operates during S phase as part of a mechanism which prevents DNA damage causing cell lethality. This process may involve the bypass of DNA damage sites by the replication fork. Finally, in contrast with the reported literature, we do not find that rqh1 (rad12) mutant cells are defective in UV dimer endonuclease activity
Risk factors for house-entry by malaria vectors in a rural town and satellite villages in The Gambia.
Background:
In the pre-intervention year of a randomized controlled trial investigating the protective effects of house screening against malaria-transmitting vectors, a multi-factorial risk factor analysis study was used to identify factors that influence mosquito house entry.
Methods:
Mosquitoes were sampled using CDC light traps in 976 houses, each on one night, in Farafenni town and surrounding villages during the malaria-transmission season in The Gambia. Catches from individual houses were both (a) left unadjusted and (b) adjusted relative to the number of mosquitoes caught in four sentinel houses that were operated nightly throughout the period, to allow for night-to-night variation. Houses were characterized by location, architecture, human occupancy and their mosquito control activities, and the number and type of domestic animals within the compound.
Results:
106,536 mosquitoes were caught, of which 55% were Anopheles gambiae sensu lato, the major malaria vectors in the region. There were seven fold higher numbers of An. gambiae s.l. in the villages (geometric mean per trap night = 43.7, 95% confidence intervals, CIs = 39.5–48.4) than in Farafenni town (6.3, 5.7–7.2) and significant variation between residential blocks (p < 0.001). A negative binomial multivariate model performed equally well using unadjusted or adjusted trap data. Using the unadjusted data the presence of nuisance mosquitoes was reduced if the house was located in the town (odds ratio, OR = 0.11, 95% CIs = 0.09–0.13), the eaves were closed (OR = 0.71, 0.60–0.85), a horse was tethered near the house (OR = 0.77, 0.73–0.82), and churai, a local incense, was burned in the room at night (OR = 0.56, 0.47–0.66). Mosquito numbers increased per additional person in the house (OR = 1.04, 1.02–1.06) or trapping room (OR = 1.19, 1.13–1.25) and when the walls were made of mud blocks compared with concrete (OR = 1.44, 1.10–1.87).
Conclusion:
This study demonstrates that the risk of malaria transmission is greatest in rural areas, where large numbers of people sleep in houses made of mud blocks, where the eaves are open, horses are not tethered nearby and where churai is not burnt at night. These factors need to be considered in the design and analysis of intervention studies designed to reduce malaria transmission in The Gambia and other parts of sub-Saharan Africa
Southern expansion of the brown alga Colpomenia peregrina Sauvageau (Scytosiphonales) in the Northwest Atlantic Ocean
Blackler first recorded Colpomenia peregrina in the Northwest Atlantic based on collections from Nova Scotia, Canada. Five decades later we found large quantities of C. peregrina in Maine, USA, even though it was absent during earlier floristic studies in this region. Thus, C. peregrina has undergone a rapid southern expansion along the Northwest Atlantic coast. While the causes of such an expansion are unknown, it could have a major effect on both shellfish cultivation and native seaweeds within New England because of competitive interactions and increased drag
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Child Exploitation and the FIFA World Cup: A review of risks and protective interventions
This review was commissioned by the Child Abuse Programme (CAP) of Oak Foundation, a large international philanthropic organisation. It forms part of CAP’s effort to win societal rejection of practices such as the sexual exploitation of children and adolescents around major sporting events (MSEs), and to embed prevention and protection from exploitation as a permanent concern for global sports-related bodies. This review is intended to inform action in countries that host MSEs and to provide some suggestions on how hosting countries can avoid past pitfalls and mistakes in relation to child exploitation, especially economic and sexual exploitation. Importantly, it also acts as a call to action by those responsible for commissioning and staging MSEs, such as FIFA and the IOC, to anticipate, prepare for and adopt risk mitigation strategies and interventions. Positive leadership from these culturally powerful bodies could prove decisive in shifting hearts, minds and actions in the direction of improved safety for children
An ecomimicry design approach for extensive green roofs
Extensive green roofs (EGRs) have been promoted as a multifunctional urban green infrastructure (UGI) solution that can ameliorate some of the negative environmental effects associated with urbanisation and provide habitat for wildlife. To date ecological EGR research remains limited, yet studying and understanding the ecology and ecological processes of these novel urban ecosystems could maximise their potential to conserve biodiversity and deliver multiple ecosystem services to urban areas. Here we present an overview of how a novel ‘ecomimicry’ approach can be used to ensure that locally important habitats are created and restored as part of urban green infrastructure strategies, and that biodiversity is embedded at the heart of EGR design. This can help urban developments meet sustainability targets and contribute to the goal of no-net-loss of biodiversity. Conserving urban biodiversity through ecomimicry will increase opportunities for urban communities to reconnect with nature and improve the quality of life for people in cities
Differences Between Students with and without Disabilities in College Counseling
This study examined differences between college students with and without disabilities who utilized college counseling center services. Although we found no differences between students with (n = 234, 9.2%) and without (n = 2,308, 90.8%) disabilities on number of counseling sessions attended, significant findings included: students with disabilities were more likely to self-terminate and more likely to be referred out than students without disabilities. Results suggest that students with disabilities are a diverse group requiring special consideration in college counseling settings. Recommendations for college counseling practice are discussed
Climate Science, Development Practice, and Policy Interactions in Dryland Agroecological Systems
The literature on drought, livelihoods, and poverty suggests that dryland residents are especially vulnerable to climate change. However, assessing this vulnerability and sharing lessons between dryland communities on how to reduce vulnerability has proven difficult because of multiple definitions of vulnerability, complexities in quantification, and the temporal and spatial variability inherent in dryland agroecological systems. In this closing editorial, we review how we have addressed these challenges through a series of structured, multiscale, and interdisciplinary vulnerability assessment case studies from drylands in West Africa, southern Africa, Mediterranean Europe, Asia, and Latin America. These case studies adopt a common vulnerability framework but employ different approaches to measuring and assessing vulnerability. By comparing methods and results across these cases, we draw out the following key lessons: (1) Our studies show the utility of using consistent conceptual frameworks for vulnerability assessments even when quite different methodological approaches are taken; (2) Utilizing narratives and scenarios to capture the dynamics of dryland agroecological systems shows that vulnerability to climate change may depend more on access to financial, political, and institutional assets than to exposure to environmental change; (3) Our analysis shows that although the results of quantitative models seem authoritative, they may be treated too literally as predictions of the future by policy makers looking for evidence to support different strategies. In conclusion, we acknowledge there is a healthy tension between bottom-up/ qualitative/place-based approaches and top-down/quantitative/generalizable approaches, and we encourage researchers from different disciplines with different disciplinary languages, to talk, collaborate, and engage effectively with each other and with stakeholders at all levels
DNA from feces and museum specimens confirms a first state record bird
In October 2005, a vagrant kingbird (Aves: Tyrannus sp.) appeared in Michigan’s Upper Peninsula, nearly 2000 km from the northern limit of its usual range. Using mitochondrial DNA obtained from a fecal sample deposited by the bird and mitochondrial DNA isolated from museum reference specimens, the species iden- tity of this bird was definitively confirmed as a Tropical Kingbird (T. melancholicus) rather than a Couch’s Kingbird (T. couchii). This is the first time DNA evidence has been used to establish a state bird record, and one of the few studies of any type to successfully use avian feces for DNA analysis. Circumstantial evidence indicates that this bird was possibly displaced from its original range by Hurricane Wilma in October, 2005. Identification of vagrant birds is important for studying avian populations, and non-invasive genetic sampling techniques should be considered when traditional means of identification fail to provide definitive evidence of identity
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