Evidence of crossover phenomena in wind speed data

In this report, a systematic analysis of hourly wind speed data obtained from three potential wind generation sites (in North Dakota) is analyzed. The power spectra of the data exhibited a power-law decay characteristic of $1/f^{\alpha}$ processes with possible long-range correlations. Conventional analysis using Hurst exponent estimators proved to be inconclusive. Subsequent analysis using detrended fluctuation analysis (DFA) revealed a crossover in the scaling exponent ($\alpha$). At short time scales, a scaling exponent of $\alpha \sim 1.4$ indicated that the data resembled Brownian noise, whereas for larger time scales the data exhibited long range correlations ($\alpha \sim 0.7$). The scaling exponents obtained were similar across the three locations. Our findings suggest the possibility of multiple scaling exponents characteristic of multifractal signals

A Multifractal Description of Wind Speed Records

In this paper, a systematic analysis of hourly wind speed data obtained from four potential wind generation sites in North Dakota is conducted. The power spectra of the data exhibited a power law decay characteristic of $1/f^{\alpha}$ processes with possible long range correlations. The temporal scaling properties of the records were studied using multifractal detrended fluctuation analysis {\em MFDFA}. It is seen that the records at all four locations exhibit similar scaling behavior which is also reflected in the multifractal spectrum determined under the assumption of a binomial multiplicative cascade model

Minimizing the effect of sinusoidal trends in detrended fluctuation analysis

The detrended fluctuation analysis (DFA) [Peng et al., 1994] and its extensions (MF-DFA) [Kantelhardt et al., 2002] have been used extensively to determine possible long-range correlations in self-affine signals. While the DFA has been claimed to be a superior technique, recent reports have indicated its susceptibility to trends in the data. In this report, a smoothing filter is proposed to minimize the effect of sinusoidal trends and distortion in the log-log plots obtained by DFA and MF-DFA techniques

Optimization of Multiplex PCR for Multiple Locus Variable Number Tandem Repeat Analysis for \u3cem\u3eSalmonella typhimurium\u3c/em\u3e

Salmonella typhimurium infects an estimated 1.4 million in the United States and kills over five hundred annually. The current way of categorization, Pulse Field Gel Electrophoresis (PFGE) and antibiotic sensitivity testing, lack the ability to distinguish between some closely related strains. We are attempting to optimize a new technique of categorization, Multiple Locus Variable number tandem repeat Analysis (MLVA). We made changes to temperature and concentration variables within the multiplex PCR procedure to streamline the identification process. By optimizing the multiplex PCR procedure we intend to create more consistent amplification of the loci used in MLVA analysis, which will improve efficiency in differentiating S. typhimurium isolates

Twin pregnancy with rupture of cerebral arterio venous malformation with intracranial hemorrhage

Cerebral AV malformation in pregnancy is a rare condition with a prevalence rate of approximately 0.01-0.5%. It generally presents symptoms at 20-40 years of age most commonly at around 30 years of age. It affects both men and women but more prevalent in women at this age group. We presented a case of primi gravida at 22 weeks of gestation with DCDA type of twin presenting in emergency department with intracranial hemorrhage secondary to rupture of AV malformation.

Molecular Basis for the Substrate Specificity of Quorum Signal Synthases

In several Proteobacteria, LuxI-type enzymes catalyze the biosynthesis of acyl–homoserine lactones (AHL) signals using S-adenosyl– L-methionine and either cellular acyl carrier protein (ACP)-coupled fatty acids or CoA–aryl/acyl moieties as progenitors. Little is known about the molecular mechanism of signal biosynthesis, the basis for substrate specificity, or the rationale for donor specificity for any LuxI member. Here, we present several cocrystal structures of BjaI, a CoAdependent LuxI homolog that represent views of enzyme complexes that exist along the reaction coordinate of signal synthesis. Complementary biophysical, structure–function, and kinetic analysis define the features that facilitate the unusual acyl conjugation with S-adenosylmethionine (SAM). We also identify the determinant that establishes specificity for the acyl donor and identify residues that are critical for acyl/aryl specificity. These results highlight howa prevalent scaffold has evolved to catalyze quorum signal synthesis and provide a framework for the design of small-molecule antagonists of quorum signaling

Experimental investigation of bi-directional flax with ramie fibre-reinforced phenol-formaldehyde hybrid composites

Modern research focuses on natural, green, and sustainable materials that can be used to replace conventional materials. Because of their beneficial qualities, natural fibre composites are being thoroughly researched. This research focuses on the development of a flax fibre reinforced with phenol-formaldehyde resin hybridization with ramie fibre through a vacuum infusion process. Eight different sequences were fabricated using a core-sheath structure and were mechanically characterized as per ASTM standards. The fabrication technique influences the adhesion of the matrix with reinforcement. The results also reveal that composite having ramie as a sheath layer and flax as a core delivers good mechanical characteristics compared to vice versa. The laminate H exhibited highest mechanical properties among all the eight laminates produced for this study. It exhibited a tensile strength of 54 MPa, tensile modulus of 0.98 Gpa, elongation of 7.1%, flexural strength of 143 Mpa, and compressive strength of 63.65 Mpa. The stress strain curves revealed that all the laminates exhibited ductile behaviour before failing during the tensile test and flexural test, respectively. The stacking sequence of the laminate H influenced the mechanical properties exhibited by it and its counterparts. A morphological study was carried out to analyse the failure surfaces. Morphological analysis exhibited few defects in the laminate after the tests. The composites developed delivers better mechanical properties than commercial composites available on the market, which can be used in lightweight structural applications.Web of Science1422art. no. 488

Pain management of pemphigus vulgaris

Pemphigus is a rare autoimmune bullous disease which affects the mucous membranes and skin. Pemphigus vulgaris (PV) is the most prevalent type of pemphigus. PV presents with extremely painful, non- healing oral erosions. However, there are only a handful of reports addressing the pain management of PV. We would like to present a case of a painful PV, which was successfully managed

Minimizing the effect of trends on detrended fluctuation analysis of long-range correlated noise

Detrended fluctuation analysis (DFA) has been proposed as a robust technique to determine possible long-range correlations in power-law processes [1]. However, recent studies have reported the susceptibility of DFA to trends [2] which give rise to spurious crossovers and prevent reliable estimation of the scaling exponents. Inspired by these reports, we propose a technique based on singular value-decomposition (SVD) of the trajectory matrix to minimize the effect of linear, power-law, periodic and also quasi-periodic trends superimposed on long-range correlated power-law noise. The effectiveness of the technique is demonstrated on publicly available data sets [2].Comment: 15 pages, 13 Figure