The Experts below are selected from a list of 5694 Experts worldwide ranked by ideXlab platform
Richard T. Richardson - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Human Sperm Motility by Contraceptive Anti-Eppin Antibodies from Infertile Male Monkeys: Effect on Cyclic Adenosine Monophosphate1
2016Co-Authors: Michael G. O’r, Esther E. Widgren, Stan Beyler, Richard T. RichardsonAbstract:Epididymal protease inhibitor (eppin [official symbol, SPINLW1]) is of interest as a male contraceptive target because of its specificity and location on the human sperm surface. We have examined the effect of anti-eppin antibodies from infertile male monkeys and the effect of recombinant human semenoge-lin on human sperm motility. Anti-eppin antibodies significantly decreased the progressive motility of human spermatozoa as measured by decreased Total Distance Traveled, decreased straight-line Distance, and decreased velocity. Anti-eppin treat-ment of spermatozoa significantly increased the amount of cAMP present in nonprogressive spermatozoa; however, ap-proximately 25 % of antibody-treated spermatozoa could be rescued by the addition of cAMP-acetoxymethyl ester, indicating that anti-eppin-treated spermatozoa have a compromised ability to utilize cAMP. Addition of recombinant human semenogelin has a concentration-dependent inhibitory effect on progressive motility (increased tortuosity and decreased velocity). We tested the hypothesis that anti-eppin antibodies bound to eppin would subsequently block semenogelin binding to eppin. Anti-eppin antibodies from infertile monkeys inhibited eppin from binding to semenogelin. Addition of affinity-purified antibodies made to the dominant C-terminal epitope of eppin had an inhibitory effect on progressive motility (increased tortuosity, decreased velocity, and straight Distance). Our results suggest that the eppin-semenogelin binding site is critical for the removal of semenogelin in vivo during semen liquefaction and for the initiation of progressive motility. We conclude that the eppin-semenogelin binding site on the surface of human spermatozoa is an ideal target for a nonsteroidal male contraceptive. cAMP, contraception, eppin, gamete biology, semenogelin, seminal plasma, sperm, spermatozo
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inhibition of human sperm motility by contraceptive anti eppin antibodies from infertile male monkeys effect on cyclic adenosine monophosphate
Biology of Reproduction, 2009Co-Authors: Michael G Orand, Esther E. Widgren, Stan Beyler, Richard T. RichardsonAbstract:Epididymal protease inhibitor (eppin [official symbol, SPINLW1]) is of interest as a male contraceptive target because of its specificity and location on the human sperm surface. We have examined the effect of anti-eppin antibodies from infertile male monkeys and the effect of recombinant human semenogelin on human sperm motility. Anti-eppin antibodies significantly decreased the progressive motility of human spermatozoa as measured by decreased Total Distance Traveled, decreased straight-line Distance, and decreased velocity. Anti-eppin treatment of spermatozoa significantly increased the amount of cAMP present in nonprogressive spermatozoa; however, approximately 25% of antibody-treated spermatozoa could be rescued by the addition of cAMP-acetoxymethyl ester, indicating that anti-eppin-treated spermatozoa have a compromised ability to utilize cAMP. Addition of recombinant human semenogelin has a concentration-dependent inhibitory effect on progressive motility (increased tortuosity and decreased velocity). We tested the hypothesis that anti-eppin antibodies bound to eppin would subsequently block semenogelin binding to eppin. Anti-eppin antibodies from infertile monkeys inhibited eppin from binding to semenogelin. Addition of affinity-purified antibodies made to the dominant C-terminal epitope of eppin had an inhibitory effect on progressive motility (increased tortuosity, decreased velocity, and straight Distance). Our results suggest that the eppin-semenogelin binding site is critical for the removal of semenogelin in vivo during semen liquefaction and for the initiation of progressive motility. We conclude that the eppin-semenogelin binding site on the surface of human spermatozoa is an ideal target for a nonsteroidal male contraceptive.
Ismail Guvenc - One of the best experts on this subject based on the ideXlab platform.
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Correction of Channel Sounding Clock Drift and Antenna Rotation Effects for mmWave Angular Profile Measurements
IEEE Open Journal of Antennas and Propagation, 2020Co-Authors: Fatih Erden, Ozgur Ozdemir, Wahab Khawaja, Ismail GuvencAbstract:Proper characterization of the millimeter-wave (mmWave) propagation channel requires measuring the power angular-delay profile of the channel which includes angle-of-departure and angle-of-arrival of the multipath components (MPCs). In this paper, we first describe in detail our rotating directional antennas-based 28 GHz channel sounder. Then, for this specific sounder class, we describe and address the following two problems in extracting the MPCs from the measurements: 1) For long-Distance channel measurements, triggering signal cannot be generated for the TX and the RX using a single clock (SICL). This necessitates the use of separate clocks (SECLs) which introduces a random timing drift between the clocks. 2) As positions of the antennas change during scanning, Total Distance Traveled by the same MPC differs at each measurement. These problems together cause missing some of the MPCs and detecting MPCs that do not exist in reality. We propose an algorithm to correct the clock drift and MPC delay errors due to the rotation of the antennas. We compare the MPCs from the SICL measurement and the corrected SECL measurements using a Hungarian algorithm based MPC matching method. We show that the percentage of the matched MPCs increases from 28.36% to 74.13% after the correction process.
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Correction of Channel Sounding Clock Drift and Antenna Rotation Effects for mmWave Angular Profile Measurements
arXiv: Signal Processing, 2019Co-Authors: Fatih Erden, Ozgur Ozdemir, Wahab Khawaja, Ismail GuvencAbstract:Millimeter-wave (mmWave) bands will be used for the fifth generation communication systems to support high data rates. For the proper characterization of the mmWave propagation channel, it is essential to measure the power angular-delay profile (PADP) of the channel which includes angle-of-departure (AoD) and angle-of-arrival (AoA) of the multipath components (MPCs). In this paper, we first describe in detail our 28 GHz channel sounder where directional horn antennas are placed on rotating gimbals. Then, for this specific sounder class, we describe and address the following two problems in extracting the MPCs from the measurements: 1) For the channel measurements at large Distances between the transmitter (TX) and the receiver (RX), it is not possible to generate the triggering signal for the TX and the RX using a single clock (SICL). This necessitates the use of separate clocks (SECLs) which introduces a random timing drift between the clocks. 2) As the positions of the antennas change during the scanning process, Total Distance Traveled by the same MPC differs at each measurement. These two errors together cause missing some of the MPCs and detecting MPCs that do not exist in reality. We propose an algorithm to correct the clock drift and the errors in the MPC delays due to the rotation of the antennas. We compare the MPCs from the SICL measurement and the corrected SECL measurements using a Hungarian algorithm based MPC matching method. We show that the percentage of the matched MPCs increases from 28.36% to 74.13% after the correction process.
Michael G Orand - One of the best experts on this subject based on the ideXlab platform.
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inhibition of human sperm motility by contraceptive anti eppin antibodies from infertile male monkeys effect on cyclic adenosine monophosphate
Biology of Reproduction, 2009Co-Authors: Michael G Orand, Esther E. Widgren, Stan Beyler, Richard T. RichardsonAbstract:Epididymal protease inhibitor (eppin [official symbol, SPINLW1]) is of interest as a male contraceptive target because of its specificity and location on the human sperm surface. We have examined the effect of anti-eppin antibodies from infertile male monkeys and the effect of recombinant human semenogelin on human sperm motility. Anti-eppin antibodies significantly decreased the progressive motility of human spermatozoa as measured by decreased Total Distance Traveled, decreased straight-line Distance, and decreased velocity. Anti-eppin treatment of spermatozoa significantly increased the amount of cAMP present in nonprogressive spermatozoa; however, approximately 25% of antibody-treated spermatozoa could be rescued by the addition of cAMP-acetoxymethyl ester, indicating that anti-eppin-treated spermatozoa have a compromised ability to utilize cAMP. Addition of recombinant human semenogelin has a concentration-dependent inhibitory effect on progressive motility (increased tortuosity and decreased velocity). We tested the hypothesis that anti-eppin antibodies bound to eppin would subsequently block semenogelin binding to eppin. Anti-eppin antibodies from infertile monkeys inhibited eppin from binding to semenogelin. Addition of affinity-purified antibodies made to the dominant C-terminal epitope of eppin had an inhibitory effect on progressive motility (increased tortuosity, decreased velocity, and straight Distance). Our results suggest that the eppin-semenogelin binding site is critical for the removal of semenogelin in vivo during semen liquefaction and for the initiation of progressive motility. We conclude that the eppin-semenogelin binding site on the surface of human spermatozoa is an ideal target for a nonsteroidal male contraceptive.
Isaac A Adedara - One of the best experts on this subject based on the ideXlab platform.
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hazardous impact of diclofenac exposure on the behavior and antioxidant defense system in nauphoeta cinerea
Environmental Pollution, 2020Co-Authors: Isaac A Adedara, Joao Rocha, Ifeoluwa O Awogbindin, Blessing A Afolabi, Babajide O Ajayi, Ebenezer O FarombiAbstract:Abstract Environmental pollution by pharmaceuticals such as diclofenac (DCF) is globally acknowledged to be a threat to the ecosystems. Nauphoeta cinerea is an important insect with valuable ecological role. The present investigation aimed to elucidate the impact of DCF on insects by assessing the behavior and antioxidant defense response in nymphs of N. cinerea exposed to DCF-contaminated food at 0, 0.5, 1.0 and 2.0 μg kg−1 feed for 42 successive days. Subsequent to exposure period, neurobehavioral analysis using video-tracking software in a novel apparatus was performed before estimation of biochemical endpoints in the head, midgut and hemolymph of the insects. Results indicated that DCF-exposed insects exhibited marked reduction in the maximum speed, Total Distance Traveled, mobile episodes, Total mobile time, body rotation, absolute turn angle and path efficiency, whereas the Total freezing time was increased compared with the control. The diminution in the exploratory activities of DCF-exposed insects was substantiated by heat maps and track plots. Additionally, DCF elicited marked diminution in antioxidant enzyme and acetylcholinesterase (AChE) activities along with increase in nitric oxide (NO), reactive oxygen and nitrogen species (RONS), and lipid peroxidation (LPO) levels in the head, midgut and hemolymph of the insects. Taken together, DCF elicited neurotoxicity and oxido-inflammatory stress in exposed insects. N. cinerea may be a suitable model insect for environmental risk assessment of pharmaceuticals in non-target insect species.
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neurobehavioral and biochemical changes in nauphoeta cinerea following dietary exposure to chlorpyrifos
Pesticide Biochemistry and Physiology, 2016Co-Authors: Isaac A Adedara, Denis B Rosemberg, Diego De Souza, Diogo O. Souza, Ebenezer O Farombi, Michael Aschner, Joao RochaAbstract:Abstract The present study aimed to increase our understanding about the mode of toxic action of organophosphate pesticides in insects by evaluating the biochemical and neurobehavioral characteristics in Nauphoeta cinerea exposed to chlorpyrifos (CPF)-contaminated diet. The insects were exposed for 35 consecutive days to CPF at 0.078, 0.15625, 0.3125 and 0.625 μg/g feed. Locomotor behavior was assessed for a 10-min trial in a novel arena and subsequently, biochemical analyses were carried out using the cockroaches’ heads. In comparison to control, CPF-exposed cockroaches showed significant decreases in the Total Distance Traveled, body rotation, turn angle and meandering, along with significant increase in the number of falls, time and episodes of immobility. The marked decrease in the exploratory profiles of CPF-exposed cockroaches was confirmed by track plots, whereas occupancy plot analyses showed a progressive dispersion at 0.15625 μg/g feed group. Moreover, the heads of CPF-exposed cockroaches showed marked decrease in acetylcholinesterase activity and antioxidant status with concomitant significant elevation in dichlorofluorescein oxidation and lipid peroxidation levels in CPF-treated cockroaches. Gas Chromatography–Mass Spectrometry analyses revealed bioaccumulation of CPF in cockroaches exposed to concentrations above 0.078 μg/g feed. The findings from this investigation showed N. cinerea as a value model organism for the risk assessment of environmental organophosphate contamination in insects.
Dirk Cattrysse - One of the best experts on this subject based on the ideXlab platform.
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multi objective microzone based vehicle routing for courier companies from tactical to operational planning
European Journal of Operational Research, 2015Co-Authors: Jochen Janssens, Kenneth Sorensen, Joos Van Den Bergh, Dirk CattrysseAbstract:Abstract Distribution companies that serve a very large number of customers, courier companies for example, often partition the geographical region served by a depot into zones. Each zone is assigned to a single vehicle and each vehicle serves a single zone. An alternative approach is to partition the distribution region into smaller micro zones that are assigned to a preferred vehicle in a so-called tactical plan. The moment the workload in each microzone is known, the microzones can be reassigned to vehicles in such a way that the Total Distance Traveled is minimized, the workload of the different vehicles is balanced, and as many microzones as possible are assigned to their preferred vehicle. In this paper we model the resulting microzone-based vehicle routing problem as a multi-objective optimization problem and develop a simple yet effective algorithm to solve it. We analyze this algorithm and discuss the results it obtains.
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multi objective microzone based vehicle routing for courier companies from tactical to operational planning
2014Co-Authors: Jochen Janssens, Kenneth Sorensen, Joos Van Den Bergh, Dirk CattrysseAbstract:Distribution companies that serve a very large number of customers, courier companies for example, often partition the geographical region served by a depot into zones. Each zone is assigned to a single vehicle and each vehicle serves a single zone. An alternative approach is to partition the distribution region into smaller microzones that are assigned to a preferred vehicle in a so-called tactical plan. When the workload in each microzone is known, the microzones can be reassigned to vehicles in such a way that the Total Distance Traveled is minimized, the workload of the different vehicles is balanced, and as many microzones as possible are assigned to their preferred vehicle. In this paper we model the resulting microzone-based vehicle routing problem as a multi-objective optimization problem and develop a simple yet effective algorithm to solve it. We analyze this algorithm and discuss the results that it obtains.
