Distribution Of Hydrological Losses For Varying Rainfall And Antecedent Wetness Conditions

Hydrological loss is a vital component in many hydrological models, which are usedin forecasting floods and evaluating water resources for both surface and subsurface flows. Due to the complex and random nature of the rainfall runoff process, hydrological losses are not yet fully understood. Consequently, practitioners often use representative values of the losses for design applications such as rainfall-runoff modelling which has led to inaccurate quantification of water quantities in the resulting applications. The existing hydrological loss models must be revisited and modellers should be encouraged to utilise other available data sets. This study is based on three unregulated catchments situated in Mt. Lofty Ranges of South Australia (SA). The paper focuses on conceptual models for: initial loss (IL), continuing loss (CL) and proportional loss (PL) with rainfall characteristics (total rainfall (TR) and storm duration (D)), and antecedent wetness (AW) conditions. The paper introduces two methods that can be implemented to estimate IL as a function of TR, D and AW. The IL distribution patterns and parameters for the study catchments are determined using multivariate analysis and descriptive statistics. The possibility of generalising the methods and the limitations of this are also discussed. This study will yield improvements to existing loss models and will encourage practitioners to utilise multiple data sets to estimate losses, instead of using hypothetical or representative values to generalise real situations

Comparison of an immortalized human corneal epithelial cell line with Vero cells in the isolation of Herpes simplex virus-1 for the laboratory diagnosis of Herpes simplex keratitis

BACKGROUND: Herpes simplex keratitis (HSK) is a sight threatening ocular infection often requiring a specific and prompt laboratory diagnosis. Isolation of Herpes simplex virus (HSV-1) in culture provides the most reliable and specific method and is considered as the "Gold Standard" in the laboratory diagnosis of HSK in spite of its low sensitivity. Using "cell lines of corneal origin" for virus isolation may be beneficial under such circumstances, since these cells have been shown to be excellent substrates for the growth of HSV-1 isolated from the cornea. We report a comparative study of a novel human corneal epithelial cell line (HCE) and the Vero cell line in the isolation of HSV-1 from corneal scrapings employing a shell vial assay. METHODS: Corneal scrapings were obtained from 17 patients with a clinical diagnosis of HSK. All the cases were confirmed by virological investigations (PCR and viral antigen detection positive, n = 15, PCR positive, n = 1, Viral antigen positive, n = 1). Scrapings obtained from 10 patients with infectious keratitis of non-viral origin were included as controls. All the scrapings were simultaneously inoculated into shell vials of HCE and Vero cells. Cultures were terminated at 24 h post-infection. Isolation of HSV-1 was confirmed using an indirect immunofluorescence/ immunoperoxidase assay. RESULTS: Virus could be isolated using both or either of the cell lines in 10/17 (58.82%) patients with HSK. HSV-1 was isolated from 10/ 17 (58.82%) and 4/17(23.52%) specimens in HCE and Vero cells, respectively (P = 0.036). None of the controls yielded HSV-1. While all the 10 (100%) strains were isolated in HCE, Vero yielded only 4/10 (40%) strains in the shell vial culture (P = 0.014). CONCLUSIONS: HCE showed a statistically significant difference in the virus isolation rate with respect to Vero cells. HCE may be an excellent alternative cell line for the isolation of HSV-1, especially from corneal scrapings, for the laboratory diagnosis of HSK

Comparison of the sensitivity of a 24 h-shell vial assay, and conventional tube culture, in the isolation of Herpes simplex virus – 1 from corneal scrapings

BACKGROUND: Herpes simplex keratitis is a sight threatening ocular infection. A rapid and specific diagnosis is essential for the institution of specific antiviral therapy and to avoid complications that can arise from misdiagnosis and inappropriate treatment. Though a variety of techniques are available, isolation of Herpes simplex virus 1 (HSV-1) in culture provides the most reliable and specific method, and is considered as the gold standard in laboratory diagnosis of herpes simplex keratitis. We report a comparative study of the sensitivity of a 24 h-shell vial assay and conventional tube culture in the isolation of HSV-1 from corneal scrapings. METHODS: A total of 74 corneal scrapings obtained from 74 patients with a clinical suspicion of herpes simplex keratitis submitted for the isolation of HSV-1, were simultaneously inoculated into shell vial and tube cultures employing the vero cell line. Shell vial and tube cultures were terminated at 24 h and fifth day respectively. Isolation of HSV-1 was confirmed employing an indirect immunofluorescence assay. RESULTS: HSV-1 was isolated from 24/74 (32.4%) specimens employing both the methods. Sensitivity of both the techniques were found to be similar (20/24, 83.3%) (P = 1.0). CONCLUSION: A 24 h-shell vial assay is a rapid alternative technique in comparison to the time consuming conventional tube cultures for the isolation of HSV-1, especially from corneal scrapings for the laboratory diagnosis of herpes simplex keratitis

Replication protein A physically interacts with the Bloom's syndrome protein and stimulates its helicase activity.

Bloom's syndrome is a rare autosomal recessive disorder characterized by genomic instability and predisposition to cancer. BLM, the gene defective in Bloom's syndrome, encodes a 159-kDa protein possessing DNA-stimulated ATPase and ATP-dependent DNA helicase activities. We have examined mechanistic aspects of the catalytic functions of purified recombinant BLM protein. Through analyzing the effects of different lengths of DNA cofactor on ATPase activity, we provide evidence to suggest that BLM translocates along single-stranded DNA in a processive manner. The helicase reaction catalyzed by BLM protein was examined as a function of duplex DNA length. We show that BLM catalyzes unwinding of short DNA duplexes (/=259-bp). The presence of the human single-stranded DNA-binding protein (human replication protein A (hRPA)) stimulates the BLM unwinding reaction on the 259-bp partial duplex DNA substrate. Heterologous single-stranded DNA-binding proteins fail to stimulate similarly the helicase activity of BLM protein. This is the first demonstration of a functional interaction between BLM and another protein. Consistent with a functional interaction between hRPA and the BLM helicase, we demonstrate a direct physical interaction between the two proteins mediated by the 70-kDa subunit of RPA. The interactions between BLM and hRPA suggest that the two proteins function together in vivo to unwind DNA duplexes during replication, recombination, or repair

Vaccine Potential of Nipah Virus-Like Particles

Nipah virus (NiV) was first recognized in 1998 in a zoonotic disease outbreak associated with highly lethal febrile encephalitis in humans and a predominantly respiratory disease in pigs. Periodic deadly outbreaks, documentation of person-to-person transmission, and the potential of this virus as an agent of agroterror reinforce the need for effective means of therapy and prevention. In this report, we describe the vaccine potential of NiV virus-like particles (NiV VLPs) composed of three NiV proteins G, F and M. Co-expression of these proteins under optimized conditions resulted in quantifiable amounts of VLPs with many virus-like/vaccine desirable properties including some not previously described for VLPs of any paramyxovirus: The particles were fusogenic, inducing syncytia formation; PCR array analysis showed NiV VLP-induced activation of innate immune defense pathways; the surface structure of NiV VLPs imaged by cryoelectron microscopy was dense, ordered, and repetitive, and consistent with similarly derived structure of paramyxovirus measles virus. The VLPs were composed of all the three viral proteins as designed, and their intracellular processing also appeared similar to NiV virions. The size, morphology and surface composition of the VLPs were consistent with the parental virus, and importantly, they retained their antigenic potential. Finally, these particles, formulated without adjuvant, were able to induce neutralizing antibody response in Balb/c mice. These findings indicate vaccine potential of these particles and will be the basis for undertaking future protective efficacy studies in animal models of NiV disease

Cryo-Electron Tomography of Marburg Virus Particles and Their Morphogenesis within Infected Cells

Ultrastructural analysis of a filovirus assembling within infected eukaryotic cells reveals differences in structure and assembly mechanisms between related RNA viruses

The distinct roles of the nucleus and nucleus-cytoskeleton connections in three-dimensional cell migration

Cells often migrate in vivo in an extracellular matrix that is intrinsically three-dimensional (3D) and the role of actin filament architecture in 3D cell migration is less well understood. Here we show that, while recently identified linkers of nucleoskeleton to cytoskeleton (LINC) complexes play a minimal role in conventional 2D migration, they play a critical role in regulating the organization of a subset of actin filament bundles – the perinuclear actin cap - connected to the nucleus through Nesprin2giant and Nesprin3 in cells in 3D collagen I matrix. Actin cap fibers prolong the nucleus and mediate the formation of pseudopodial protrusions, which drive matrix traction and 3D cell migration. Disruption of LINC complexes disorganizes the actin cap, which impairs 3D cell migration. A simple mechanical model explains why LINC complexes and the perinuclear actin cap are essential in 3D migration by providing mechanical support to the formation of pseudopodial protrusions

The Arabidopsis BLAP75/Rmi1 Homologue Plays Crucial Roles in Meiotic Double-Strand Break Repair

In human cells and in Saccharomyces cerevisiae, BLAP75/Rmi1 acts together with BLM/Sgs1 and TopoIIIα/Top3 to maintain genome stability by limiting crossover (CO) formation in favour of NCO events, probably through the dissolution of double Holliday junction intermediates (dHJ). So far, very limited data is available on the involvement of these complexes in meiotic DNA repair. In this paper, we present the first meiotic study of a member of the BLAP75 family through characterisation of the Arabidopsis thaliana homologue. In A. thaliana blap75 mutants, meiotic recombination is initiated, and recombination progresses until the formation of bivalent-like structures, even in the absence of ZMM proteins. However, chromosome fragmentation can be detected as soon as metaphase I and is drastic at anaphase I, while no second meiotic division is observed. Using genetic and imunolocalisation studies, we showed that these defects reflect a role of A. thaliana BLAP75 in meiotic double-strand break (DSB) repair—that it acts after the invasion step mediated by RAD51 and associated proteins and that it is necessary to repair meiotic DSBs onto sister chromatids as well as onto the homologous chromosome. In conclusion, our results show for the first time that BLAP75/Rmi1 is a key protein of the meiotic homologous recombination machinery. In A. thaliana, we found that this protein is dispensable for homologous chromosome recognition and synapsis but necessary for the repair of meiotic DSBs. Furthermore, in the absence of BLAP75, bivalent formation can happen even in the absence of ZMM proteins, showing that in blap75 mutants, recombination intermediates exist that are stable enough to form bivalent structures, even when ZMM are absent

Synthetic Biology: Mapping the Scientific Landscape

This article uses data from Thomson Reuters Web of Science to map and analyse the scientific landscape for synthetic biology. The article draws on recent advances in data visualisation and analytics with the aim of informing upcoming international policy debates on the governance of synthetic biology by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) of the United Nations Convention on Biological Diversity. We use mapping techniques to identify how synthetic biology can best be understood and the range of institutions, researchers and funding agencies involved. Debates under the Convention are likely to focus on a possible moratorium on the field release of synthetic organisms, cells or genomes. Based on the empirical evidence we propose that guidance could be provided to funding agencies to respect the letter and spirit of the Convention on Biological Diversity in making research investments. Building on the recommendations of the United States Presidential Commission for the Study of Bioethical Issues we demonstrate that it is possible to promote independent and transparent monitoring of developments in synthetic biology using modern information tools. In particular, public and policy understanding and engagement with synthetic biology can be enhanced through the use of online interactive tools. As a step forward in this process we make existing data on the scientific literature on synthetic biology available in an online interactive workbook so that researchers, policy makers and civil society can explore the data and draw conclusions for themselves