713 research outputs found
Effects of cadmium on morphological structure of sperm in Caspiomyzon wagneri (Kessler, 1870) (Petromyzontiformes : Petromyzontidae)
The present study aimed to investigate effects of the heavy metal Cd on the sperm morphological indices of Caspimyzon wagneri. The sperm were exposed to 0.01, 0.1, 1, 10, 100 and 1000 mg.L-1 Cd for three minutes, three and 36 hours. The sperms exposed to Cd showed an increase in the length, width and surface of the head, flagella degradation and slightly flagella breakage. With increase of Cd concentration or the exposure duration, the damages found in sperms increased. But when exposure to contaminant exceeds than certain period of time,damage effects caused changes in the sperm structure as head length reduction and head width increasing and thereby reducing the sperm’s head surface, complete cutting of flagella at all samples and deformation of the sperm’s head from oval to circular, which these changes became visible during 36 hours of exposure to cadmium.Therefore, the results revealed that the arrival of pollutants including cadmium to the natural reproduction ground of this species due to induction the harmful effects on sperm morphology factors will have adverse effects on sperm function and fertilization rate and reduce them, and as such will be considered a serious threat to the survival generation of this rare species
The effect of Pogostone on viability, membrane integrity, and apoptosis of liver cancer cells
OBJECTIVE: The incidence of liver cancer is still high in many countries, including Iran. Drug resistance and various side effects are the main obstacles to treating this cancer. Herbs, which are traditionally used, are now widely regarded as treatment options for cancer. Pogostone is a natural substance isolated from Indian mint (Pogostemon cablin) and has various medicinal activities. This study aimed to determine the effect of Pogostone on liver cancer cell line (viability, membrane integrity, and apoptosis).
MATERIALS AND METHODS: The liver cancer cell line was prepared from Pasteur Institute of Iran and treated with appropriate concentrations of Pogostone. Cytotoxicity was determined by MTT, trypan blue, and lactate dehydrogenase assay. Apoptosis induction was evaluated by diphenylamine assay, Annexin V-FITC staining and a Real-time PCR test. Data were analyzed by SPSS statistical software using Tukey’s test one-way analysis of variance.
RESULTS: After all three time periods, a significant decrease in viability was observed (p <0.05) in a concentration- and time-dependent manner. The cytotoxicity of Pogostone to liver cancer cells was in a concentration- and time-dependent manner. Pogostone significantly induced apoptosis compared to control cells (p<0.05). Treatment of liver cancer cells with Pogostone significantly reduced Bcl-2 gene expression (p<0.05). On the other hand, expression of all three Bax, p53, and caspase 3 genes showed a significant increase after treatment (p<0.05).
CONCLUSIONS: Pogostone had a concentration- and time-dependent toxic effect on liver cancer cells. It induced apoptosis by increasing the Bax to Bcl-2 ratio
Fast, vision-based line-following schemes for micro-aerial vehicles in nuclear environments
Many nuclear power plants are reaching the end of their economic lifetime and the decommissioning of legacy nuclear facilities is an important challenge in the next few decades. Since the radiation level in these facilities is significant, autonomous robots are likely to be a large part of the solution. For this purpose, the mapping and inspection of nuclear facilities can be performed using autonomous Micro Aerial Vehicles (MAVs). Recently, there are many studies on achieving a stable and reliable MAV flight to perform accurate missions with high performance. Since human access is highly restricted in nuclear environments, conventional navigation systems are not able to complete many of the required tasks. Track follower MAVs have been implemented in many applications, such as water channels and railway inspections. To illustrate some of the issues involved, this research considers a line-following method and compares two attitude controllers. The approach can be divided into three tasks: 1) the image processing algorithm, 2) the path planning strategy and 3) attitude stabilisation. The environment under study contains a ground floor with predetermined red tracks over which the MAV moves. We explain each task briefly in the following. Image Processing: First, a colour detection algorithm is applied to form a thresholded image. To make the image smoother and to reduce noise effects, Dilation and Erosion algorithms are applied. Then, in each iteration, a vector is created by the boundary layer of the provided image. Morphological operations are performed to remove small discontinuities for each cluster. Here the goal is to find the midpoint of each cluster, known as keypoints. Finally, the obtained vector should be re-mapped to its original image matrix. Path Planning: The methodology for selecting the appropriate target point is to compare the distance between the keypoints and the target. For the take-off phase, the keypoint with smaller y in the image frame is chosen and, for the remaining iterations, the keypoint with lower distance to the target is selected. Then, the desired velocity in the body frame is calculated. Attitude Controller Design: Two controllers are considered to stabilise the attitude of the MAV. First, a linear Proportional-Integral-Derivative (PID) controller is selected. A linear PID control for yaw torque is derived. Subsequently, a conventional sliding surface for the yaw channel is defined and, by applying Lyapunov’s direct method, the stability of the system is guaranteed. The yaw control torque is derived as a function of the designed positive sliding gain. Finally, to avoid chattering phenomenon, one can approximate the discontinuous signum function with the hyperbolic one
A novel mutation in SEPN1 causing rigid spine muscular dystrophy 1: A Case report
Abstract Background Muscular dystrophies are a clinically and genetically heterogeneous group of disorders characterized by variable degrees of progressive muscle degeneration and weakness. There is a wide variability in the age of onset, symptoms and rate of progression in subtypes of these disorders. Herein, we present the results of our study conducted to identify the pathogenic genetic variation involved in our patient affected by rigid spine muscular dystrophy. Case presentation A 14-year-old boy, product of a first-cousin marriage, was enrolled in our study with failure to thrive, fatigue, muscular dystrophy, generalized muscular atrophy, kyphoscoliosis, and flexion contracture of the knees and elbows. Whole-exome sequencing (WES) was carried out on the DNA of the patient to investigate all coding regions and uncovered a novel, homozygous missense mutation in SEPN1 gene (c. 1379 C > T, p.Ser460Phe). This mutation has not been reported before in different public variant databases and also our database (BayanGene), so it is classified as a variation of unknown significance (VUS). Subsequently, it was confirmed that the novel variation was homozygous in our patient and heterozygous in his parents. Different bioinformatics tools showed the damaging effects of the variant on protein. Multiple sequence alignment using BLASTP on ExPASy and WebLogo, revealed the conservation of the mutated residue. Conclusion We reported a novel homozygous mutation in SEPN1 gene that expands our understanding of rigid spine muscular dystrophy. Although bioinformatics analyses of results were in favor of the pathogenicity of the mutation, functional studies are needed to establish the pathogenicity of the variant
Development and implementation of water safety plans for groundwater resources in the southernmost city of West Azerbaijan Province, Iran
The transfer of water from the source to the consumption point is always associated with the possibility of contamination in any of its various components. To resolve this problem, the World Health Organization has considered a water safety plan. The purpose of this study is to implement water safety plan in the water supply system of Bukan city. This study was performed on Bukan’s water supply system in 2019–20 using a software to guarantee the quality of the water safety plan and the WHO and IWA guidelines. The software checklists were prepared and after confirming the validity of the translation and its facial and content validity, it was completed based on the records of the Water and Sewerage Company and interviews with experts. Out of a total of 440 points of full-application of the program and 392 points for the reviewed phases, 183.6 points were acquired and 43.7% of WSP-coordinated implementation was observed. The highest percentage of WSP-coordinated implementation (75.2%) was assigned to the validation stage with the highest point, and the support program stage had the lowest percentage of performance (1.1%). Among the major components of the water supply system, the final consumption point received the most attention from the system. Given the lifespan of the introduction and use of WSP in the world, it was expected that better results would be obtained from evaluating the implementation and progress of this approach in Bukan’s water supply system. However, the implementation rate of this program in this city compared to other cities in Iran, showed that according to the implementation time (one year), the obtained results are relatively convincing and good and the water supply system has a moderate level of safety
Colour-Octet Effects in Radiative Decays
We investigate the effects of colour-octet contributions to the radiative
decay within the Bodwin, Braaten and Lepage NRQCD factorization
framework. Photons coming both from the coupling to hard processes (`direct')
and by collinear emission from light quarks (`fragmentation') are consistently
included at next-to-leading order (NLO) in . An estimate for the
non-perturbative matrix elements which enter in the final result is then
obtained. By comparing the NRQCD prediction at NLO for total decay rates with
the experimental data, it is found that the non-perturbative parameters must be
smaller than expected from the na\"\i ve scaling rules of NRQCD. Nevertheless,
colour-octet contributions to the shape of the photon spectrum turn out to be
significant.Comment: 25 pages, Latex, 8 figure
Co-transplantation of Human Embryonic Stem Cell-derived Neural Progenitors and Schwann Cells in a Rat Spinal Cord Contusion Injury Model Elicits a Distinct Neurogenesis and Functional Recovery
Co-transplantation of neural progenitors (NPs) with Schwann cells (SCs) might be a way to overcome low rate of neuronal differentiation of NPs following transplantation in spinal cord injury (SCI) and the improvement of locomotor recovery. In this study, we initially generated NPs from human embryonic stem cells (hESCs) and investigated their potential for neuronal differentiation and functional recovery when co-cultured with SCs in vitro and co-transplanted in a rat acute model of contused SCI. Co-cultivation results revealed that the presence of SCs provided a consistent status for hESC-NPs and recharged their neural differentiation toward a predominantly neuronal fate. Following transplantation, a significant functional recovery was
observed in all engrafted groups (NPs, SCs, NPs+SCs) relative to the vehicle and control groups.
We also observed that animals receiving co-transplants established a better state as assessed with
the BBB functional test. Immunohistofluorescence evaluation five weeks after transplantation
showed invigorated neuronal differentiation and limited proliferation in the co-transplanted
group when compared to the individual hESC-NPs grafted group. These findings have
demonstrated that the co-transplantation of SCs with hESC-NPs could offer a synergistic effect,
promoting neuronal differentiation and functional recovery
Combining CP Asymmetries in Decays
We prove an approximate relation, to leading order in dominant terms, between
CP-violating rate differences in and
. We show how data from these two processes may be
combined in order to enhance the significance of a nonzero result.Comment: 9 pages, latex, no figures, submitted to Phys. Rev. Letters, revise
Determination of the Michel Parameters and the tau Neutrino Helicity in tau Decay
Using the CLEO II detector at the storage ring CESR, we have
determined the Michel parameters , , and in decay as well as the tau neutrino helicity parameter
in decay. From a data sample of
tau pairs produced at , using events of
the topology and , and the determined sign of , the combined
result of the three samples is: , , , and
. The results are in agreement with
the Standard Model V-A interaction.Comment: 18 page postscript file, postscript file also available through
http://w4.lns.cornell.edu/public/CLN
Kinematic Effects in Radiative Quarkonia Decays
Non-relativistic QCD (NRQCD) predicts colour octet contributions to be
significant not only in many production processes of heavy quarkonia but also
in their radiative decays. We investigate the photon energy distributions in
these processes in the endpoint region. There the velocity expansion of NRQCD
breaks down which requires a resummation of an infinite class of colour octet
operators to so-called shape functions. We model these non-perturbative
functions by the emission of a soft gluon cluster in the initial state. We
found that the spectrum in the endpoint region is poorly understood if the
values for the colour octet matrix elements are taken as large as indicated
from NRQCD scaling rules. Therefore the endpoint region should not be taken
into account for a fit of the strong coupling constant at the scale of the
heavy quark mass.Comment: LaTeX, 17 pages, 5 figures. The complete paper is also available via
the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints
- …