Fungal biofilms as low-modulus structural biocomposites

Biofilms are formed by microorganisms that collectively organise at interfaces. They are self-assembling complex fluids consisting of rigid microbial cells embedded in a self-secreted soft biopolymeric extracellular matrix and possess an intricate porous network that holds nearly 90% by weight of water. Biofilms have been commonly studied for their ability to spread infection and corrode industrial equipment. Biomaterials produced by microorganisms such as bacterial cellulose, and more recently fungal mycelium-based biocomposites, typically require downstream processing to improve their mechanical strength. Research questions: Can non-pathogenic biofilms find applications as useful biomaterials? Can biofilms be grown as biocomposites, thereby circumventing the need for downstream processing

Influence of carbon source complexity on porosity, water retention and extracellular matrix composition of Neurospora discreta biofilms

Aims To evaluate carbon source complexity as a process lever to impact the microstructure, chemical composition and water retention capacity of biofilms produced by Neurospora discreta. Methods and Results Biofilms were produced by non‐pathogenic fungus N. discreta, using sucrose, cellulose or lignin as carbon source. Increase in complexity of carbon source from sucrose to lignin resulted in decreased water retention values (WRV) and wet weights of harvested biofilms. Confocal laser scanning microscopy (CLSM) was used to calculate porosity from bright field images, and relative stained areas of cells and carbohydrates from fluorescence imaging of samples stained with Trypan blue and Alexa Fluor 488. Porosity and relative quantity of cells increased with increase in carbon source complexity while the amount of carbohydrates decreased. Chemical analysis of the extracted extracellular matrix (ECM) showed that biofilms grown on more complex carbon sources had lower carbohydrate and protein content, which also explains the lower WRV trend, as carbohydrates are hydrophilic. Conclusions The nature of carbon source impacts the metabolic pathway of cells, thereby influencing the relative proportions of ECM and cells. This in turn impacts the microstructure, composition and water content of biofilms. Significance and Impact of the Study This work shows that carbon source can be used as process lever to control the properties of biofilms and presents a novel view of biofilms as potentially useful biomaterials

Roles of various virulence and resistance genes associated with Salmonella and methods of their identification

Salmonellosis is an infectious disease affecting human and animals. The virulence of Salmonella is a function of chromosomal and plasmid factors, many genes code for these factors. Salmonella genes can be classified as core (housekeeping) genes and accessory genes. The core genes of a species are those genes found in (nearly) all known members of the species and they include mostly genes that are necessary for the cell to survive and grow, these include gene encoding enzymes which function in biosynthetic pathways. Genes in the accessory genome are those unique to particular strains and are mainly in the following groups: genomic islands including Salmonella Pathogenicity islands (SPls), prophages, insertion sequences.Keywords: Genes, Pathogenicity, Resistance, Salmonella, Virulenc

Productivity of Apple as Influenced by Rates of Nitrogen, Phosphorus and Irrigation Interval

Field experiment was conducted on an established orchard of the Kaduna State Agricultural Development Project (KADP) at Maigana during the 1998- 2001 to evaluate the effect of nitrogen, phosphorus and irrigation interval on some selected growth attributes of apple. The treatments consisted of four levels of nitrogen (0, 60, 120 and 180 kg N h -1, three levels of phosphorus (0, 22 and 44) and irrigation intervals (3, 5 and 7 days). Treatments were laid out in a split plot design with factorial combination of nitrogen and irrigation interval allocated to main plots and phosphorus assigned to sub-plots and replicated three times. The result showed that application of nitrogen up to 180 kg N ha -1 resulted to taller plants with more branches and wider canopy as well as thicker stem and heavier fruit yield. Likewise, applications of phosphorus up to 44 kg P ha -1 resulted to taller plants, more branches, wider canopy, thicker stem and heavier fruit yield. There was inconsistency in response of the parameters to irrigation interval, however the yield responded up to 7 days irrigation interval. It can be concluded that for proper apple growth, application of 180 kg N ha -1 plus 44 kg P ha -1, with 7 days irrigation interval should be adopted. Keywords: fruit yield, nitrogen, phosphorus, irrigation and nitrogen conten

A three-Phase shunt active power filter with unified constant frequency integration control with RLC connection circuit

This paper discusses a Modular Structure Multilevel Inverter (MSMI) with a Unified Constant Frequency Integration Control (UPC) which is used as an Active Power Filter (APF). APF is connected in shunt to the power system in order to sense the non-sinusoidal current drawn by the non-linear load and inject current to the transmission line which compensates the harmonics drawn by the load. This in turn helps having a power factor value close to one at the source side since the source current is forced to follow the source and thus be in phase with it. An APF topology is simulated for different connection parameters and its performance for each case is studied. Finally the results are compared to show that the topology proposed in this paper has a better harmonic reduction

Direct and Indirect Detection of Dark Matter in D6 Flavor Symmetric Model

We study a fermionic dark matter in a non-supersymmetric extension of the standard model with a family symmetry based on D6xZ2xZ2. In our model, the final state of the dark matter annihilation is determined to be e+ e- by the flavor symmetry, which is consistent with the PAMELA result. At first, we show that our dark matter mass should be within the range of 230 GeV - 750 GeV in the WMAP analysis combined with mu to e gamma constraint. Moreover we simultaneously explain the experiments of direct and indirect detection, by simply adding a gauge and D6 singlet real scalar field. In the direct detection experiments, we show that the lighter dark matter mass ~ 230 GeV and the lighter standard model Higgs boson ~ 115 GeV is in favor of the observed bounds reported by CDMS II and XENON100. In the indirect detection experiments, we explain the positron excess reported by PAMELA through the Breit-Wigner enhancement mechanism. We also show that our model is consistent with no antiproton excess suggested by PAMELA.Comment: 20 pages, 9 figures, 2 tables, accepted version for publication in European Physical Journal

Are pathogenic leptospira species agents of community-acquired pneumonia? case reports of leptospirosis presenting as pneumonia

We report four Indonesian cases meeting the clinical and radiological criteria for community-acquired pneumonia and other findings suggestive of leptospirosis. Quantitative PCR (qPCR) analyses of serum and urine samples and serology confirmed the diagnosis of leptospirosis in each. Results of qPCR analysis of throat swabs were concordant with those obtained with acutephase serum samples, which suggests its potential for use as a noninvasive diagnostic tool for leptospirosis

Epidemiology of Stroke in the MENA Region: A Systematic Review.

Introduction: Stroke is a major burden on the health system due to high fatality and major disability in survivors. Whilst Stroke incidence has declined in the developed world, it continues to increase in developing nations, including the MENA (Middle East and North Africa) region. This may reflect different risk factors and strategies to treat and manage patients prior to and after Stroke. Methods: We have conducted a systematic review of the prevalence, incidence and mortality of Stroke in the 23 countries of MENA region following the PRISMA guidelines. Results: 8,874 published papers were retrieved through both PubMed and Embase. Of those, 38 studies were found to be eligible for inclusion in this review. Only thirteen countries in the MENA region had data points for the critical stroke parameters. Of these qualified studies, 14 were prospective, population-based studies. In the age-adjusted studies, incidence ranged widely between 16/100,000 in a prospective population-based in Iran to 162/100,000 in Libya. Age-adjusted prevalence was available only from Tunisia at 184/100,000. Mortality for all strokes from the eight countries reporting this measure found the 30 day-case fatality ranged from 9.3% in Qatar to 30% in Pakistan. Most stroke studies in the MENA region were small sized, hospital-based, lacked confidence intervals and did not provide prevalence and mortality figures. Conclusion: National policymakers, public health and medical care stakeholders need more reliable epidemiologic studies on Stroke from the MENA region to plan more effective preventive and therapeutic strategies