553 research outputs found
Optimized Virtual Vector Technique with Loss Minimization of Six Phase IM Under Low-Speed Operation for Electric Vehicles
Last-male sperm precedence in Rhynchophorus ferrugineus (Olivier): observations in laboratory mating experiments with irradiated males
The Red PalmWeevil (RPW)Rhynchophorus ferrugineus(Olivier 1790) is an invasive
pest from southeastern Asia and Melanesia that in the last 30 years has spread widely
in the Middle East and Mediterranean Basin. Its stem-boring larvae cause great damage to several palm species of the Arecaceae family, many of which are economically
important for agricultural and ornamental purposes. Therefore, great attention has recently been focused in studying this species to identify sustainable and effective eradication strategies, such as sterile insect technique (SIT). The rapid spread of RPW is
associated with its high reproductive success. To evaluate the suitability of a SIT strategy, particular physiological and behavioral aspects of RPW reproduction, such as the
presence of polyandry and post-copulatory sperm selection mechanisms, were
investigated. To determine paternity of progeny from multiply mated females, double-crossing experiments were carried out confining individual females with either a
wild-type male or a γ-irradiated male (Co-60). Fecundity and fertility of females were
scored to evaluate post-copulatory sperm selection. Results showed that progeny
were almost exclusively produced by the sperm of the second male, suggesting that
a last-male sperm precedence is expressed at high levels in this species, and providing
interesting insights for an area-wide RPW management strategy such as the SIT
Outcomes following autologous hematopoietic stem cell transplant for patients with relapsed Wilms' tumor: a CIBMTR retrospective analysis.
Despite the marked improvement in the overall survival (OS) for patients diagnosed with Wilms' tumor (WT), the outcomes for those who experience relapse have remained disappointing. We describe the outcomes of 253 patients with relapsed WT who received high-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplant (HCT) between 1990 and 2013, and were reported to the Center for International Blood and Marrow Transplantation Research. The 5-year estimates for event-free survival (EFS) and OS were 36% (95% confidence interval (CI); 29-43%) and 45% (95 CI; 38-51%), respectively. Relapse of primary disease was the cause of death in 81% of the population. EFS, OS, relapse and transplant-related mortality showed no significant differences when broken down by disease status at transplant, time from diagnosis to transplant, year of transplant or conditioning regimen. Our data suggest that HDT followed by autologous HCT for relapsed WT is well tolerated and outcomes are similar to those reported in the literature. As attempts to conduct a randomized trial comparing maintenance chemotherapy with consolidation versus HDT followed by stem cell transplant have failed, one should balance the potential benefits with the yet unknown long-term risks. As disease recurrence continues to be the most common cause of death, future research should focus on the development of consolidation therapies for those patients achieving complete response to therapy
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Examining bias in estimating the response variable and assessing the effect of using alternative plot designs to measure predictor variables in diameter growth modeling
Diameter growth of Douglas-fir (Pseudotsuqa menziesii (Mirb.) Franco) estimated from increment cores was compared with that obtained from repeated measurements of tree diameter on permanent plots located in two Douglas-fir study areas in the central Coast Range of Oregon. Growth was measured for a 6-year period (1979-
1985). Diameter growth measured from two increment cores taken opposite to each other, provided an unbiased estimate of the stand average diameter-growth as determined from repeated measurements of diameter. However, a statistically significant trend was found in the differences in individual tree diameter-growth between the two methods of measurements. A nonlinear
model was used to characterize these differences. The practical significance of the observed trend and the use of the developed model as a calibration tool, depend upon the reliability desired by the particular user. The second part was a simulation study to examine the effect upon growth model predictions of using
alternative sample plot designs to measure predictor variables. Five forest stands were generated through computer simulation by use of field data and random spatial distributions. Two variable-radius plot designs and four fixed-radius circular plots were used to sample simultaneously the generated stands . Sample data then were used to simulate diameter and gross-basal-area growth in both a single-tree/distance-independent growth model and a whole-stand/diameter-free growth model. In comparing the growth predictions of each model, the plot design used to develop the model was the standard against which alternative plot designs were evaluated. Both fixed and variable area plots provide, with varying degree of precision, unbiased estimates of stand-level predictor variables. For both models, average gross basal area
growth-rate predictions from 50 samples of each alternative design were not significantly different from the standard design. However, large differences in individual predictions may occur as a result of using a different plot design. The magnitude of these differences depend on the stand size and density
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Effects of stand density on site index in thinned stands of Douglas-fir in the Pacific Northwest
In site index studies, the hypothesis that height
growth of most conifers is independent of stand density
is commonly accepted. However, some studies have shown
height growth to be influenced by density particularly
on medium to poor sites.
In this study two locations representing a high
quality site (Hoskins area, Oregon) and a relatively
lower site (Rocky Brook area, Washington) were selected
to examine the effect of stand density on site index in
natural stands of Douglas-fir which has been repeatedly
thinned at different intensities. The data for the
study were obtained from the periodic measurements of
the stand characteristics at the end of each thinning
treatment period. The average height of the largest 40
trees per acre was used as basis for the comparison of
height growth patterns among the different thinning
regimes.
Simple linear regression was found adequate to
describe height growth of the individual plots over the
age range studied (20 to 36 years at the Hoskins and 27
to 44 years at the Rocky Brook). Covariance analysis
using multiple regression was used to test differences
in height growth within plots under similar thinning
treatments. The coefficients of the height growth
equations from individual plots were used in the
analysis to test for differences in height growth among
the different thinning regimes.
The results of the study indicated that on both
sites, site index was not influenced by density over a
wide range of stocking and within the age range studied
Chemical Investigation of Some Capparis Species Growing in Egypt and their Antioxidant Activity
Capparis cartilaginea and C. deserti growing in Egypt were investigated for their glucosiolates and rutin content. From Capparis cartilaginea four isothiocynates were isolated and identified using GC and EI/MS techniques. These compounds were butyl isothiocyanate (1), 6-methylsulphonylhexyl isothiocyanate (2), 7-methylsulphonylheptyl isothiocyanate (3) and 5-benzylsulphonyl-4-pentenyl isothiocyanate (4). In addition to compounds (1) and (2), two other compounds were isolated and identified from Capparis deserti. These compounds are 3-methylthiopropyl isothiocyanate (5) and [11-(2-butenylthio)6-undecenyl isothiocyanate] (6). Compounds (1), (2), (5) and (6) are reported in this study for the first time from Capparis deserti. The main flavonoid component in the studied species was isolated and identified as rutin by comparing the data with those reported. Also, quantitative evaluation of rutin in the two species was carried out by TLC-densitometric analysis. The antioxidant activity was done using diphenylpicrylhydrazyl (DPPH) radical scavenging method. The butanol fraction from C. cartilaginea and C. deserti showed the highest antioxidant properties
GRFS and CRFS in alternative donor hematopoietic cell transplantation for pediatric patients with acute leukemia.
We report graft-versus-host disease (GVHD)-free relapse-free survival (GRFS) (a composite end point of survival without grade III-IV acute GVHD [aGVHD], systemic therapy-requiring chronic GVHD [cGVHD], or relapse) and cGVHD-free relapse-free survival (CRFS) among pediatric patients with acute leukemia (n = 1613) who underwent transplantation with 1 antigen-mismatched (7/8) bone marrow (BM; n = 172) or umbilical cord blood (UCB; n = 1441). Multivariate analysis was performed using Cox proportional hazards models. To account for multiple testing, P \u3c .01 for the donor/graft variable was considered statistically significant. Clinical characteristics were similar between UCB and 7/8 BM recipients, because most had acute lymphoblastic leukemia (62%), 64% received total body irradiation-based conditioning, and 60% received anti-thymocyte globulin or alemtuzumab. Methotrexate-based GVHD prophylaxis was more common with 7/8 BM (79%) than with UCB (15%), in which mycophenolate mofetil was commonly used. The univariate estimates of GRFS and CRFS were 22% (95% confidence interval [CI], 16-29) and 27% (95% CI, 20-34), respectively, with 7/8 BM and 33% (95% CI, 31-36) and 38% (95% CI, 35-40), respectively, with UCB (P \u3c .001). In multivariate analysis, 7/8 BM vs UCB had similar GRFS (hazard ratio [HR], 1.12; 95% CI, 0.87-1.45; P = .39), CRFS (HR, 1.06; 95% CI, 0.82-1.38; P = .66), overall survival (HR, 1.07; 95% CI, 0.80-1.44; P = .66), and relapse (HR, 1.44; 95% CI, 1.03-2.02; P = .03). However, the 7/8 BM group had a significantly higher risk for grade III-IV aGVHD (HR, 1.70; 95% CI, 1.16-2.48; P = .006) compared with the UCB group. UCB and 7/8 BM groups had similar outcomes, as measured by GRFS and CRFS. However, given the higher risk for grade III-IV aGVHD, UCB might be preferred for patients lacking matched donors. © 2019 American Society of Hematology. All rights reserved
COMPARATIVE ANALYSIS OF BIOLOGICAL ACTIVITY OF SILYBUM MARIANUM L. FOOD SUPPLEMENTS AVAILABLE ON MARKET: INVITRO STUDY
Objective: Silybum marianum L. Food Supplements that contain silymarin is widely used as a therapeutic agent in liver diseases. Many brands are available on the market in USA, Egypt, Europe and other countries. The objective of this study was to compare the biological activity in different preparations of silymarin available on the market in USA and Egypt using paracetamol-induced oxidative stress injury on primary cultured rat hepatocytes.
Methods: Forty four silymarin samples available on the market were collected from USA (24) and Egypt (20) and tested for hepat protective antioxidant effects on primary cultured rat hepatocytes. Cytotoxicity was measured by MTT [3-(4, 5-dimethyl-thiazol-2)-2,5-diphenyl tetrazolium bromide] assay and lactate dehydrogenase (LD) leakage into culture medium. Antioxidant effects were determined by glutathione reductase (GR), and Nitric oxide (NO) assays in silymarin, pretreated rat hepatocytes for 2 h followed by incubation with 25 mM paracetamol over a period of 1 h. Therapeutic index was calculated for each tested sample for comparative analysis.
Results: Silymarin preparations significantly decreased toxicity induced by paracetamol in rat hepatocytes, decreased lactate dehydrogenase leakage and prevented GSH depletion (P<0.01) and returned NO to basal levels in rat hepatocytes. The therapeutic index was 80, 40 and 20 for samples No. 20, 19 and 5 respectively.
Conclusions: The 44 different silymarin preparations tested in this study exhibited variation in antioxidant capacity and in reducing nitric oxide produced as a result of paracetamol injury. This variation in biological activity did not always correspond to the amount of silymarin recorded on samples
Single-Phase Charging of Six-Phase Integrated On-Board Battery Charger using Predictive Current Control
This work was achieved by the financial support of ITIDAs ITAC collaborative funded project under the category type of advanced research projects (ARP) and Grant Number ARP2020.R29.7.This work was achieved by the financial support of ITIDAs ITAC collaborative funded project under the category type of advanced research projects (ARP) and Grant Number ARP2020.R29.7.Integrated On-Board Battery Chargers (IOBCs) have shown promise as an elegant charging solution for electric vehicles in recent literature. Although the three-phase charging technique of IOBCs has extensively been discussed in the literature, single-phase charging is still a challenging research topic. The Predictive Current Control (PCC) approach has shown many benefits, including a straightforward algorithm, simple implementation, comparatively quick response, and appropriate performance, when compared to conventional control techniques. This paper investigates the impact of single-phase charging of a six-phase-based IOBC system with different winding configurations using PCC, which, up to the best authors’ knowledge, has not been conceived thus far. Under single-phase charging, the zero-sequence current component is utilized to ensure zero torque production during charging mode. Since the impedance of the zero subspace is highly affected by the employed winding design, the performance of PCC with different winding layouts of either induction machine (IM) or permanent magnet synchronous machine (PMSM) is investigated and compared. The proposed method is experimentally validated using a 1.1kW six-phase IM and a 2 kW 12-slot/10-pole PMSM. Finite Element analysis is also carried out to investigate the effect of single-phase charging mode on the induced radial forces and vibration level when PM machine is employed
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