Weak-value amplification and optimal parameter estimation in the presence of correlated noise

We analytically and numerically investigate the performance of weak-value amplification (WVA) and related parameter estimation methods in the presence of temporally correlated noise. WVA is a special instance of a general measurement strategy that involves sorting data into separate subsets based on the outcome of a second "partitioning" measurement. Using a simplified noise model that can be analyzed exactly together with optimal statistical estimators, we compare WVA to a conventional measurement method. We find that introducing WVA indeed yields a much lower variance of the parameter of interest than does the conventional technique, optimized in the absence of any partitioning measurements. In contrast, a statistically optimal analysis that employs partitioning measurements, incorporating all partitioned results and their known correlations, is found to yield an improvement -- typically slight -- over the noise reduction achieved by WVA. This is because the simple WVA technique is not tailored to a given noise environment and therefore does not make use of correlations between the different partitions. We also compare WVA to traditional background subtraction, a familiar technique where measurement outcomes are partitioned to eliminate unknown offsets or errors in calibration. Surprisingly, in our model background subtraction turns out to be a special case of the optimal partitioning approach in the balanced case, possessing a similar typically slight advantage over WVA. These results give deeper insight into the role of partitioning measurements, with or without post-selection, in enhancing measurement precision, which some have found puzzling. We finish by presenting numerical results to model a more realistic laboratory situation of time-decaying correlations, showing our conclusions hold for a wide range of statistical models.Comment: Revisions incorporate feedback from reviewer

Observing the Onset of Effective Mass

The response of a particle in a periodic potential to an applied force is commonly described by an effective mass which accounts for the detailed interaction between the particle and the surrounding potential. Using a Bose-Einstein condensate of 87-Rb atoms initially in the ground band of an optical lattice, we experimentally show that the initial response of a particle to an applied force is in fact characterized by the bare mass. Subsequently, the particle response undergoes rapid oscillations and only over timescales long compared to that of the interband dynamics is the effective mass observed to be an appropriate description

Three-dimensional electrical impedance tomography to monitor unsaturated moisture ingress in cement-based materials

The development of tools to monitor unsaturated moisture flow in cement-based material is of great importance, as most degradation processes in cement-based materials take place in the presence of moisture. In this paper, the feasibility of electrical impedance tomography (EIT) to monitor three-dimensional (3D) moisture flow in mortar containing fine aggregates is investigated. In the experiments, EIT measurements are taken during moisture ingress in mortar, using electrodes attached on the outer surface of specimens. For EIT, the so-called difference imaging scheme is adopted to reconstruct the change of the 3D electrical conductivity distribution within a specimen caused by the ingress of water into mortar. To study the ability of EIT to detect differences in the rate of ingress, the experiment is performed using plain water and with water containing a viscosity-modifying agent yielding a slower flow rate. To corroborate EIT, X-ray computed tomography (CT) and simulations of unsaturated moisture flow are carried out. While X-ray CT shows contrast with respect to background only in highly saturated regions, EIT shows the conductivity change also in the regions of low degree of saturation. The results of EIT compare well with simulations of unsaturated moisture flow. Moreover, the EIT reconstructions show a clear difference between the cases of water without and with the viscosity-modifying agent and demonstrate the ability of EIT to distinguish between different flow rates

Cloning, expression and purification of escherichia coli modified phytase

Introduction: Phytases are the class of phosphatases, which are capable of hydrolyzing phytic acid. Phytases with the phytate degradation are able to reduce or eliminate the harmful effects of phytate. Acidic and thermal stable phytase with high yield and purity by a relatively inexpensive system had extensive application. So, in this study, by modification in enzyme sequence, recombinant phytase production with the shorter length and high expression level was assessed. Materials and Methods: The phytase gene sequence was obtained from the NCBI database. After bioinformatics studies and doing the noted modification for increasing protein expression, gene proliferation was done by using PCR. E. coli BL21 (DE3) was used to express the protein. Protein purification was performed by Ni-NTA kit and finally, enzyme activity was assessed. Results: Phytase was successfully expressed and purified. Enzyme activity assay showed a significant activity. Conclusion: Produced recombinant phytase had high activity in spite of eliminating parts of the enzyme. © 2017, Semnan University of Medical Sciences. All rights reserved

Common bile duct stone associated with hemolytic uremic syndrome

Cholelithiasis is an unusual complication of hemolytic uremic syndrome. A 12-year-old boy with hemolytic uremic syndrome, established by renal biopsy, who developed cholestatic jaundice is presented here. Laboratory results for secondary causes of hemolytic uremic syndrome were normal. Abdominal ultrasonography and magnetic resonance cholangiopancreatography revealed extrahepatic obstruction. A common bile duct stone, discovered by retrograde cholanglopancreatography was extracted by sphincterotomy. In conclusion, cholelithiasis should be considered as a cause of abdominal pain and cholestasis in patients who are diagnosed as having hemolytic uremic syndrome

Invisibility and indistinguishability in structural damage tomography

Structural damage tomography (SDT) uses full-field or distributed measurements collected from sensors or self-sensing materials to reconstruct quantitative images of potential damage in structures, such as civil structures, automobiles, aircraft, etc. In approximately the past ten years, SDT has increased in popularity due to significant gains in computing power, improvements in sensor quality, and increases in measurement device sensitivity. Nonetheless, from a mathematical standpoint, SDT remains challenging because the reconstruction problems are usually nonlinear and ill-posed. Inasmuch, the ability to reliably reconstruct or detect damage using SDT is seldom guaranteed due to factors such as noise, modeling errors, low sensor quality, and more. As such, damage processes may be rendered invisible due to data indistinguishability. In this paper we identify and address key physical, mathematical, and practical factors that may result in invisible structural damage. Demonstrations of damage invisibility and data indistinguishability in SDT are provided using experimental data generated from a damaged reinforced concrete beam

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran

BACKGROUND: Pityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins. METHODS: Differentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin. RESULTS: In pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species. CONCLUSIONS: According to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered

Biology and seasonal fluctuation of cottony camellia scale, Pulvinaria (Chloropulvinaria) floccifera (Hemiptera: Coccidae) in Citrus orchards of northern Iran

Abstract Cottony camellia scale, Pulvinaria floccifera Westwood is almost cosmopolitan having been spread widely by the plant trade. This soft scale is one of the most important scales of citrus orchards in Mazandaran and Guilan provinces. The biology and seasonal fluctuation of pest was studied in natural conditions in the West of Mazandaran. Furthermore, the biology of this soft scale was studied in laboratory condition. To study population dynamics, 10 leaves from each five Thomson navel orange trees, Citrus sinensis L. were taken every two weeks. P. floccifera completed one generation per year, hibernating as an adult insect. The last overwintering females were observed in early June and Middl