Study of growth ring formation on scales of mullet Liza saliens in the Caspian Sea

This study is attempted to compare the number of rings and circular scales that are formed during various ages on Liza saliens. Sampling was carried out monthly during 2012-2013 using beach seine fishing nets. 102 specimens of different sizes were collected and transferred to the laboratory in boxes containing ice. The age of fish was determined by the number of annual rings as well as, the number of rings in each annual area. The distance between rings in each annual area was also measured. The results showed that the maximum growth was demonstrated in the first and second years. In the first year of life, the scale radius was nearly 2823.3±366.5(µm) which decreased to 1223.9±236.0(µm). The result indicated that 48 percentage of growth scales occurred in the first year and this value is only 21.8% in the second year. The number of growth rings in the annual regions decreased with increase in age. The result demonstrated that the average number of rings was 95.5±17.6 in the first life year of the fish. If you take into account the number of growth ring through years in comparison with the number of days in a year, it is clear that one ring was nearly made in four days in the first life year and it gradually reached 7.5, 15.9, 21.9 and 31.7 in the second, fourth and sixth years of life, respectively. One ring was approximately made in each month at higher ages

Design of output feedback UPFC controller for damping electromechanical oscillations using

a b s t r a c t In this paper, a novel method for the design of output feedback controller for unified power flow controller (UPFC) is developed. The selection of the output feedback gains for the UPFC controllers is converted to an optimization problem with the time domain-based objective function which is solved by a particle swarm optimization technique (PSO) that has a strong ability to find the most optimistic results. Only local and available state variables are adopted as the input signals of each controller for the decentralized design. Thus, structure of the designed UPFC controller is simple and easy to implement. To ensure the robustness of the proposed stabilizers, the design process takes into account a wide range of operating conditions and system configurations. The effectiveness of the proposed controller for damping low frequency oscillations is tested and demonstrated through nonlinear time-domain simulation and some performance indices studies. The results analysis reveals that the designed PSO-based output feedback UPFC damping controller has an excellent capability in damping power system low frequency oscillations and enhance greatly the dynamic stability of the power systems. Moreover, the system performance analysis under different operating conditions show that the d E based controller is superior to both the m B based controller and conventional power system stablizer

Prevalence of amyloid deposition in long standing rheumatoid arthritis in Iranian patients by abdominal subcutaneous fat biopsy and assessment of clinical and laboratory characteristics

BACKGROUND: The study was aimed at determining the prevalence of secondary amyloidosis in a group of Iranian patients with Rheumatoid Arthritis (RA), and the assessment of its correlation with the clinical and laboratory findings and data. METHOD: A total number of 220 patients (167 female and 53 male) with a minimum five-year history of RA were selected. Congo red staining method was used for staining the specimens obtained by abdominal subcutaneous fat biopsy (ASFB) method. All of the specimens were examined for apple-green birefringence under polarized light microscope. Clinical and laboratory characteristics of the patients were assessed. Chi-square test and unpaired student's t-test were run for intergroup comparisons. RESULTS: Amyloid deposition test yielded positive results in 15 out of the 220 cases (6.8%) examined by the ASFB technique. Thirteen patients were found to have minimal amyloid deposits. Of all the clinically significant cases, 8 (53%) presented with proteinuria, and 7 cases (46.6%) had severe constipation. CONCLUSION: The prevalence of fat amyloid deposits in Iranian patients with RA is low. In up to half of the study group the deposits were subclinical. Follow up studies are required to determine whether this subclinical amyloidosis can develop into full-blown clinically significant amyloidosis

Solubility of Tris(hydroxymethyl)aminomethane in Water + 1-Propanol Mixtures at Various Temperatures

Article on the solubility of tris(hydroxymethyl)aminomethane in water + 1-propanol mixtures at various temperatures

Laparoscopic resection of gastric duplication cyst containing gastrointestinal stromal tumour: A case report

Gastric duplication cyst (GDC) in adults is an extremely rare congenital anomaly. Here, we report the case of a GDC containing gastrointestinal stromal tumour (GIST) in a 60-year-old male patient who presented with abdominal pain. Laparoscopic resection with safe margins was performed following endosonographic localisation of the lesion. Pathologic evaluation revealed GDC containing GIST, and all surgical margins were free from tumours. The patient was discharged with good condition after 2 days and after 3 months of follow-up, the patient was symptom free and had no complications. Gastric duplication is a rare disease and may contain heterotopic tissue or even neoplastic lesions. Definite treatment is complete surgical removal that can be achieved laparoscopically with the aid of intraoperative ultrasonography for precise localisation of the indeterminate lesions. © 2020 Journal of Minimal Access Surgery | Published by Wolters Kluwer-Medknow

Comparison of three different statistical approaches (non-linear least-squares regression, survival analysis and Bayesian inference) in their usefulness for estimating hydrothermal time models of seed germination

Hydrothermal time (HTT) models describe the time course of seed germination for a population of seeds under specific temperature and water potential conditions. The parameters of the HTT model are usually estimated using either a linear regression, non-linear least squares estimation or a generalized linear regression model. There are problems with these approaches, including loss of information, and censoring and lack of independence in the germination data. Model estimation may require optimization, and this can have a heavy computational burden. Here, we compare non-linear regression with survival and Bayesian methods, to estimate HTT models for germination of two clover species. All three methods estimated similar HTT model parameters with similar root mean squared errors. However, the Bayesian approach allowed (1) efficient estimation of model parameters without the need for computation-intensive methods and (2) easy comparison of HTT parameters for the two clover species. HTT models that accounted for a species effect were superior to those that did not. Inspection of credibility intervals and estimated posterior distributions for the Bayesian HTT model shows that it is credible that most HTT model parameters were different for the two clover species, and these differences were consistent with known biological differences between species in their germination behaviour

Quantifying perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.) seed germination responses to water potential and temperature with a hydrothermal time model

In New Zealand, a commonly sown pasture combination is perennial ryegrass with white clover. The hydrothermal time model (HTT) was used to quantify germination under different temperature (T) and water potential (WP) conditions for white clover ‘Nomad’ and perennial ryegrass ‘Stellar AR1’. Seeds were germinated in vitro under a range of T × WP combinations, and HTT models were fitted to germination time course data. Rapid germination of white clover under optimum T and WP was reflected by a much lower value for its HTT constant compared with perennial ryegrass (10.8 vs 80.7 MPa °C d). However, the lower base water potential for perennial ryegrass (−1.29 vs −0.495 MPa) and a higher threshold temperature for thermoinhibition (21.8 vs 18.3°C), meant that predicted perennial ryegrass germination was more resilient in warm dry conditions. HTT models can be used to assist decisions about the timing of perennial ryegrass and white clover sowing