The emergence of degradative biofilms

The aim of this work was to determine the role of cellular recombination and positioning in the emergence of biofilm communities. This involved monitoring a biofilm community cultivated in a flow cell and subjected to cyclic environmental transitions from labile to refractory substrates. Laser microscopy of flow cells revealed that transitions from labile to refractory substrates resulted in a decrease in the thickness and percent area coverage of the biofilm communities. Repeated inoculation of flow cell communities with a composite inoculum resulted in an increase in the number and diversity of emigrants as well as greater thickness and area coverage of the biofilms than when the communities were inoculated only at the beginning of the experiment. This suggested that juxtapositioning through organismal recombination enhanced the growth of biofilm communities subjected to environmental stresses. Repeated environmental cycling also enhanced the growth of biofilm communities, suggesting that the functionality of cellular positioning may have accrued from one cycle to another, representing a form of heritable community-level information. Patterns of emigration that emerged during adaptation of biofilm communities to substrate transitions showed the appearance and disappearance of discrete sets of organisms. In addition, when biofilm communities cultivated using tryptic soy broth (TSB) were plated on benzoate-containing agar, higher plating efficiencies were detected at lower dilutions. This was concomitant with the formation of satellite colonies around primary colonies of benzoate-resistant bacteria. Plating assays and radiolabeled-benzoate mineralization experiments revealed that efficient benzoate degradation by the primary colonies protected the satellite strains against inhibitory concentrations of sodium benzoate. This protection also occurred during batch and flow cell cultivation. When a microbial community derived from a pristine soil environment was subjected to a substrate shift from TSB to benzoate, inclusion of a benzoate-degrading strain of Pseudomonas fluorescens (BD1) enhanced community stability. This suggested that bacteria may respond to environmental stresses as sets of spatially-related organisms as opposed to functioning exclusively as individuals. The emergence of protective synergisms also suggests that strategies based on association between microorganisms should be a consideration in food preservation, human health as well as in biodegradation

Dry sliding wear properties of Jute/polymer composites in high loading applications

In the last few decades natural fiber composites has gained its importance due to its low cost and their availability as additives with minimal processing. Amongst the various natural sources the Jute fiber is chosen in the present research due to its fiber structure and good physical and mechanical properties. In this background natural fiber composites of unsaturated polyester were reinforced with jute fibers. While most research on green composites focuses on the structural characteristics, the present work investigates the suitability of the material to be used as a tribocomposite. Tailor made hybrid composites were made with chemically treated (NaOH) jute fiber and 2 wt % PTFE filler (tribo lubricant) to obtain the better tribological characteristics in high loading condition. Tribotests were performed on flat on flat configuration where 100Cr6 steel was used as counterface material. A pv limit of 400 MPa-mm/s (10KN and 100 mm/s) was attainedin a flat-on-flat configuration for studying the tribological properties. The static and dynamic coefficient of friction was found to be 0.15 and 0.07 respectively.An exponential increase in temperature was observed throughout the test. The material failure was observed within 500 m of sliding distance where pulverization of matrix due to thermal degradation is evident. Wear mechanisms such as fiber breakage, polymer degradation, fiber thinning and fiber separation was observed. From the present investigation the low cost Jute fabric composites havinglow frictional coefficient seemed to be a alternative to the bearing materials working at higher contact pressure and low velocity

Energy optimization by using pinch analysis for chlorination process in glove manufacturing plant

The manufacturing industry has been driven to reduce its energy use due to the rising cost of fossil fuels and their detrimental environmental impact. Energy audits are frequently used to improve energy efficiency. Most audits, on the other hand, do not include a comprehensive review of design features for optimal energy efficiency. In thermochemical industries, pinch technology analysis, which includes heat exchanger design and retrofits, is becoming more common as a way to enhance energy efficiency. Investigations into pinch analysis have been conducted in a number of industrial and processing facilities. However, no research on pinch analysis studies in the chlorination process in glove manufacturing plant has been reported. Therefore, the use of pinch technology analysis to chlorination process in a glove manufacturing plant is presented in this study. With the help of HINT software, the goal of this study is to use a model to optimize the heat exchanger network of chlorination process in the glove manufacturing plant and to estimate the minimum cost required for the heat exchanger network without compromising the energy demand by each stream. In order to increase the energy efficiency, retrofit analysis is done for the existing system in the plant and grassroot design will be created for chlorination process setup for the upcoming new glove manufacturing plants. From the study, the improved HEN in the retrofit design shows theoretical saving of energy cost by $278,630.17 per year and necessary capital investment is$ 175,056 with the payback period of 0.63 years. The total energy savings obtained from the retrofit design is estimated around 58.41% from the initial operating costs of old system. In addition, the grassroot HEN diagram for the new plant setup estimated to save maximum theoretical recoverable energy around 14,617,960 kW per year with the total cost of $ 475,083.70 per year. Based on the savings and investment made for the new setup, the payback period is around 1.83 years

Data mining of plasma peptide chromatograms for biomarkers of air contaminant exposures

<p>Abstract</p> <p>Background</p> <p>Interrogation of chromatographic data for biomarker discovery becomes a tedious task due to stochastic variability in retention times arising from solvent and column performance. The difficulty is further compounded when the effects of exposure (e.g. to environmental contaminants) and biological variability result in varying numbers and intensities of peaks among chromatograms.</p> <p>Results</p> <p>We developed a software tool to correct the stochastic time shifts in chromatographic data through iterative selection of landmark peaks and isometric interpolation to improve alignment of all chromatographic peaks. To illustrate application of the tool, plasma peptides from Fischer rats exposed for 4 h to clean air or Ottawa urban particles (EHC-93) were separated by HPLC with autofluorescence detection, and the retention time shifts between chromatograms were corrected (dewarped). Both dewarped and non-dewarped datasets were then mined for models containing peptide peaks that best discriminate among the treatment groups using ClinproTools™. In general, models generated by dewarped datasets were able to better classify test sample chromatograms into either clean air or EHC-93 exposure groups, and 0 or 24 h post-recovery time groups. Peak areas of peptides in a model that produced the best discrimination of treatment groups were analyzed by two-way ANOVA with exposure (clean air, EHC-93) and recovery time (0 h, 24 h) as factors. Statistically significant (p < 0.05) time-dependent and exposure-dependent increases and decreases were noted establishing these as biomarker candidates for further validation.</p> <p>Conclusion</p> <p>Our software tool provides a simple and portable approach for alignment of chromatograms with complex, bi-directional retention time shifts prior to data mining. Reliable biomarker discovery can be achieved through chromatographic dewarping using our software followed by pattern recognition by commercial data mining applications.</p

Carbon Nanotube from Unconventional Precursor-Optimization of Synthesis Parameters

Carbon is a versatile element of distinctive properties and has been described as the key element of living substance. Carbon nanostructures have attracted lots of interest, due their prominent properties. Spray pyrolysis method is adopted for synthesis of carbon nanotubes (CNTs). Contrast to any petroleum product, there is no fear of its ultimate shortage as it is a renewable source and can be obtained easily by cultivating as much quantity as required. Synthesize well crystalline multiwalled carbon nanotubes (MWNTs) from unconventional precursor of methyl ester of Helianthus annuus oil by optimize the parameters such as reaction temperature, catalyst composition and feed rate of carbon precursor in order to obtain good yield with desirable morphology

Biodegradation and Bioconversion of Hydrocarbons

This book details three main topics: the screening and characterization of hydrocarbons from air, soil and water; tehnologies in the biodegradation of hydrocarbons; and the bioconversion of hydrocarbons for biofuel/chemicals, as well as recent developments in the remediation of hydrocarbons and their environmental benefits. The first section focusses on screening methods, qualitative and quantitative analysis of hydrocarbons from soil, air and water environments. The second section examines technologies for removing hydrocarbon contaminants from various environments, especially advanced technologies for the removal of hydrocarbons and in-situ and ex-situ remediation strategies and problems, as well as concrete case studies. The last section, covering the bioconversion of hydrocarbons for biofuel/chemicals highlights the biochemicals and bioproducts developed from hydrocarbons, with a particular focus on biochemical and chemical technologies used to produce biopolymers, biofuel precursors and commodity chemicals from hydrocarbons

Recycling of Solid Waste for Biofuels and Bio-chemicals

This book presents the latest advances in and current research perspectives on the field of urban/industrial solid waste recycling for bio-energy and bio-fuel recovery. It chiefly focuses on five main areas, namely bioreactor landfills coupled with energy and nutrient recovery; microbial insights into anaerobic digestion; greenhouse gas emission assessment; pyrolysis techniques for special waste treatment; and industrial waste stabilization options. In addition, it compiles the results of case studies and solid waste management perspectives from different countries

Sleep duration in school-age children with epilepsy: A cross-sectional study

Background: Normal sleep is required for the optimal growth and development of the children. Ineffective or inadequate sleep is common in children with epilepsy. Objectives: The objectives of this study were to study the sleep duration and describe the factors affecting it in school-aged children with epilepsy attending the seizure clinic of a pediatric tertiary care hospital. Materials and Methods: 6–12-year-old children with epilepsy, attending the seizure clinic formed the study subjects. They were assessed for inclusion in the study using INCLEN diagnostic tool for epilepsy (INDT-Epi) to achieve a sample size of 139. Informed written consent was obtained from parents. Background sociodemographic information, seizure type and treatment details, and duration of sleep of the child were collected from the parents. The proportion of children with epilepsy who had sleep problems were expressed as percentage. Results: The mean age of study population was 9.07±2.09 years. The average sleep duration of the study population was 9.41±1.41 h. The mean nap time of the study population was 68.51±33.88 min. No significant association was seen among the factors that determine sleep duration. Conclusion: Children with epilepsy tend to sleep for lesser hours when compared to historic controls of normal school-age children reported in literature

Amino Acids Involved in Polyphosphate Synthesis and Its Mobilization Are Distinct in Polyphosphate Kinase-1 from Mycobacterium tuberculosis

In bacteria polyphosphates (poly-P) are involved in cellular metabolism and development especially during stress. The enzyme, principally involved in polyphosphate biosynthesis and its mobilization leading to generation of NTPs, is known as polyphosphate kinase (PPK). PPK1 crystal structure since it owes 68% amino acid sequence similarity with mPPK1. Interestingly, our results revealed that mutations in mPPK1 affecting poly-P synthesis always affected its ATP synthesizing ability; however, the reverse may not be true. only

A Multi-Channel Neural Graphical Event Model with Negative Evidence

Event datasets are sequences of events of various types occurring irregularly over the time-line, and they are increasingly prevalent in numerous domains. Existing work for modeling events using conditional intensities rely on either using some underlying parametric form to capture historical dependencies, or on non-parametric models that focus primarily on tasks such as prediction. We propose a non-parametric deep neural network approach in order to estimate the underlying intensity functions. We use a novel multi-channel RNN that optimally reinforces the negative evidence of no observable events with the introduction of fake event epochs within each consecutive inter-event interval. We evaluate our method against state-of-the-art baselines on model fitting tasks as gauged by log-likelihood. Through experiments on both synthetic and real-world datasets, we find that our proposed approach outperforms existing baselines on most of the datasets studied.Comment: AAAI 202