Characterizing how fish communities and physical habitat structure are affected by urbanization in an East Tennessee watershed

Urbanization alters watershed hydrology, which leads to degradation of physical and biological components of urban streams. A part of this scenario is thought to be a product of increased storm water runoff due to excessive impervious surface. Impervious surface runoff increases the peak discharge in urban streams, causing a flushing or rapid flooding effect to occur. This flushing effect can overwhelm the natural pattern and profile of a stream channel, causing degradation of habitat and the fish population. This study investigates urbanization effects on habitat structure and fish communities in a rapidly urbanizing watershed in East Tennessee. Field measures of habitat complexity and fish indices of biotic integrity (IBI) were gathered for twenty-four stream reaches in the Beaver Creek watershed, Knox County, Tennessee. Habitat inventory produced 291 Channel Geomorphic Units (CGU) with up to 20 measurements taken in each unit. Average width and depth measurements were performed on 10 different types of pools. IBI sampling produced 7185 fish, yielding 21 species of 7 families in the 24 sites. A combination of Pearson correlations, multiple and simple linear regression, and Analysis of Variance (ANOVA) means separation techniques were used to see if changes in measured habitat and fish metrics occurred in relation to increased urbanization. Potential urbanization effects on physical habitat structure and fish communities were first considered at the (p\u3c .10) significance, using the Pearson correlation technique. Multiple and linear regressions were used to explain the strongest relationships found for fish and habitat, to increase in urbanization (p\u3c0.05). ANOVA means separation was used to examine and validate relationships found using the six sub-watersheds as treatments, and the four reaches within each sub-watershed as replicates. Mosaics of urban land use varied from 1 to 54% in the watershed catchments. The statistical techniques described earlier were employed to gather relationships found between fish and habitat sites relative to an urbanization gradient. Measures of physical habitat structure were weakly correlated with percent urbanization. As percent urbanization increased, IBI scores decreased (p = 0.0004), and the number of darters decreased (p = 0.0041). Sub- watersheds significantly differed for IBI scores (p = 0.0015), and for curve number values (p = 0.0048). Results suggest that within the range of urbanization used for this study (1 to 54% total urban and 1 to 18% commercial/ industrial) channel geomorphic units such as scour pools and riffles are not significantly altered. However, fish community assemblages did show a shift towards impairment as quantified by the IBI. This indicates that a stressor other than physical habitat degradation causes a negative effect on fish in the Beaver Creek watershed

RUASN: A Robust User Authentication Framework for Wireless Sensor Networks

In recent years, wireless sensor networks (WSNs) have been considered as a potential solution for real-time monitoring applications and these WSNs have potential practical impact on next generation technology too. However, WSNs could become a threat if suitable security is not considered before the deployment and if there are any loopholes in their security, which might open the door for an attacker and hence, endanger the application. User authentication is one of the most important security services to protect WSN data access from unauthorized users; it should provide both mutual authentication and session key establishment services. This paper proposes a robust user authentication framework for wireless sensor networks, based on a two-factor (password and smart card) concept. This scheme facilitates many services to the users such as user anonymity, mutual authentication, secure session key establishment and it allows users to choose/update their password regularly, whenever needed. Furthermore, we have provided the formal verification using Rubin logic and compare RUASN with many existing schemes. As a result, we found that the proposed scheme possesses many advantages against popular attacks, and achieves better efficiency at low computation cost

Chemically induced solidification : a new way to produce thin solid-near- net shapes

In-situ observation of the solidification of high carbon steel (4 wt% C) through decarburization has been carried out as a feasibility study into reducing high power usage and high CO2 production involved in steel making. Decarburization has been carried out under both air and pure N2 atmospheres at temperature of 1573K (1300 °C) and 1673K (1400 °C). A solidified shell of around 500μm was formed with carbon concentrations reduced down to 1% in as short as 18s

Multiplex sequencing of paired-end ditags (MS-PET): a strategy for the ultra-high-throughput analysis of transcriptomes and genomes

The paired-end ditagging (PET) technique has been shown to be efficient and accurate for large-scale transcriptome and genome analysis. However, as with other DNA tag-based sequencing strategies, it is constrained by the current efficiency of Sanger technology. A recently developed multiplex sequencing method (454-sequencing™) using picolitre-scale reactions has achieved a remarkable advance in efficiency, but suffers from short-read lengths, and a lack of paired-end information. To further enhance the efficiency of PET analysis and at the same time overcome the drawbacks of the new sequencing method, we coupled multiplex sequencing with paired-end ditagging (MS-PET) using modified PET procedures to simultaneously sequence 200 000 to 300 000 dimerized PET (diPET) templates, with an output of nearly half-a-million PET sequences in a single 4 h machine run. We demonstrate the utility and robustness of MS-PET by analyzing the transcriptome of human breast carcinoma cells, and by mapping p53 binding sites in the genome of human colorectal carcinoma cells. This combined sequencing strategy achieved an approximate 100-fold efficiency increase over the current standard for PET analysis, and furthermore enables the short-read-length multiplex sequencing procedure to acquire paired-end information from large DNA fragments

On the use of nanocellulose as reinforcement in polymer matrix composites

AbstractNanocellulose is often being regarded as the next generation renewable reinforcement for the production of high performance biocomposites. This feature article reviews the various nanocellulose reinforced polymer composites reported in literature and discusses the potential of nanocellulose as reinforcement for the production of renewable high performance polymer nanocomposites. The theoretical and experimentally determined tensile properties of nanocellulose are also reviewed. In addition to this, the reinforcing ability of BC and NFC is juxtaposed. In order to analyse the various cellulose-reinforced polymer nanocomposites reported in literature, Cox–Krenchel and rule-of-mixture models have been used to elucidate the potential of nanocellulose in composite applications. There may be potential for improvement since the tensile modulus and strength of most cellulose nanocomposites reported in literature scale linearly with the tensile modulus and strength of the cellulose nanopaper structures. Better dispersion of individual cellulose nanofibres in the polymer matrix may improve composite properties

Cardiac remodeling and dysfunction in nephrotic syndrome

There is an increased incidence of heart disease in patients with chronic nephrotic syndrome (NS), which may be attributable to the malnutrition and activated inflammatory state accompanying the sustained proteinuria. In this study, we evaluated renal function, cardiac morphometry, contractile function, and myocardial gene expression in the established puromycin aminonucleoside nephrosis rat model of NS. Two weeks after aminonucleoside injection, there was massive proteinuria, decreased creatinine clearance, and a negative sodium balance. Skeletal and cardiac muscle atrophy was present and was accompanied by impaired left ventricular (LV) hemodynamic function along with decreased contractile properties of isolated LV muscle strips. The expression of selected cytokines and proteins involved in calcium handling in myocardial tissue was evaluated by real time polymerase chain reaction. This revealed that the expression of interleukin-1beta, tumor necrosis factor-alpha, and phospholamban were elevated, whereas that of cardiac sarco(endo)plasmic reticulum calcium pump protein was decreased. We suggest that protein wasting and systemic inflammatory activation during NS contribute to cardiac remodeling and dysfunction

Workshop on Immunizations in Older Adults: Identifying Future Research Agendas

Goals for immunization in older adults may differ from those in young adults and children, in whom complete prevention of disease is the objective. Often, reduced hospitalization and death but also averting exacerbation of underlying chronic illness, functional decline, and frailty are important goals in the older age group. Because of the effect of age on dendritic cell function, T cell-mediated immune suppression, reduced proliferative capacity of T cells, and other immune responses, the efficacy of vaccines often wanes with advanced age. This article summarizes the discussion and proceedings of a workshop organized by the Association of Specialty Professors, the Infectious Diseases Society of America, the American Geriatrics Society, the National Institute on Aging, and the National Institute of Allergy and Infectious Diseases. Leading researchers and clinicians in the fields of immunology, epidemiology, infectious diseases, geriatrics, and gerontology reviewed the current status of vaccines in older adults, identified knowledge gaps, and suggest priority areas for future research. The goal of the workshop was to identify what is known about immunizations (efficacy, effect, and current schedule) in older adults and to recommend priorities for future research. Investigation in the areas identified has the potential to enhance understanding of the immune process in aging individuals, inform vaccine development, and lead to more-effective strategies to reduce the risk of vaccine-preventable illness in older adults.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79340/1/j.1532-5415.2010.02772.x.pd

Gradient Descent Optimization in Gene Regulatory Pathways

BACKGROUND: Gene Regulatory Networks (GRNs) have become a major focus of interest in recent years. Elucidating the architecture and dynamics of large scale gene regulatory networks is an important goal in systems biology. The knowledge of the gene regulatory networks further gives insights about gene regulatory pathways. This information leads to many potential applications in medicine and molecular biology, examples of which are identification of metabolic pathways, complex genetic diseases, drug discovery and toxicology analysis. High-throughput technologies allow studying various aspects of gene regulatory networks on a genome-wide scale and we will discuss recent advances as well as limitations and future challenges for gene network modeling. Novel approaches are needed to both infer the causal genes and generate hypothesis on the underlying regulatory mechanisms. METHODOLOGY: In the present article, we introduce a new method for identifying a set of optimal gene regulatory pathways by using structural equations as a tool for modeling gene regulatory networks. The method, first of all, generates data on reaction flows in a pathway. A set of constraints is formulated incorporating weighting coefficients. Finally the gene regulatory pathways are obtained through optimization of an objective function with respect to these weighting coefficients. The effectiveness of the present method is successfully tested on ten gene regulatory networks existing in the literature. A comparative study with the existing extreme pathway analysis also forms a part of this investigation. The results compare favorably with earlier experimental results. The validated pathways point to a combination of previously documented and novel findings. CONCLUSIONS: We show that our method can correctly identify the causal genes and effectively output experimentally verified pathways. The present method has been successful in deriving the optimal regulatory pathways for all the regulatory networks considered. The biological significance and applicability of the optimal pathways has also been discussed. Finally the usefulness of the present method on genetic engineering is depicted with an example

Cytomegalovirus generates long-lived antigen-specific NK cells with diminished bystander activation to heterologous infection

Natural killer (NK) cells play a key role in the host response to cytomegalovirus (CMV) and can mediate an enhanced response to secondary challenge with CMV. We assessed the ability of mouse CMV (MCMV)–induced memory Ly49H(+) NK cells to respond to challenges with influenza, an acute viral infection localized to the lung, and Listeria monocytogenes, a systemic bacterial infection. MCMV-memory NK cells did not display enhanced activation or proliferation after infection with influenza or Listeria, as compared with naive Ly49H(+) or Ly49H(−) NK cells. Memory NK cells also showed impaired activation compared with naive cells when challenged with a mutant MCMV lacking m157, highlighting their antigen-specific response. Ex vivo, MCMV-memory NK cells displayed reduced phosphorylation of STAT4 and STAT1 in response to stimulation by IL-12 and type I interferon (IFN), respectively, and IFN-γ production was reduced in response to IL-12 + IL-18 compared with naive NK cells. However, costimulation of MCMV-memory NK cells with IL-12 and m157 antigen rescues their impaired response compared with cytokines alone. These findings reveal that MCMV-primed memory NK cells are diminished in their response to cytokine-driven bystander responses to heterologous infections as they become specialized and antigen-specific for the control of MCMV upon rechallenge