Developmental responses to fluctuations in environmental conditions in echinoid echinoderms

Animals that reside, reproduce, and develop in nearshore habitats are often exposed to strong fluctuations in abiotic conditions, including temperature and salinity. We studied the developmental responses of five echinoid echinoderms (sea urchins and sand dollars) to increased temperature and reduced salinity. We aimed to document two recently described phenomena: delay of hatching (DOH) and polyembryony. First, we found that DOH is a widespread response to reduced salinity. Hatching was delayed by 79% in Echinarachnius parma, 26% in Strongylocentrotus droebachiensis, 22% in Lytechinus variegatus, and 17% in Dendraster excentricus. Only embryos of Arbacia punctulata failed to delay hatching in response to reduced salinity. Second, we observed polyembryony in both of the irregular echinoids studied (E. parma and D. excentricus). In D. excentricus, we tested the competency of twinned and normal embryos to reach metamorphosis. We found that twin embryos generated from a single egg are both capable of reaching metamorphosis. To investigate the mechanisms underlying polyembryony, we tested whether reduced Calcium levels in low salinity seawater reduce cell-cell adhesion and allow cells to separate and develop as multiple embryos within a fertilization envelope. We also tested whether osmotic stress caused swelling of the fertilization envelope, allowing embryos more room to produce multiples, or delay hatching into a later, larger stage. However, neither reduced Calcium levels nor osmotic stress alone appears sufficient to induce polyembryony. We currently hypothesize that early suppression of the hatching enzyme plays a major role in the delaying hatching and that the swelling of the hyaline layer within the fertilization envelope may facilitate polyembryony

Improvement of Power Quality in Primary Distribution Systems Based on Static-Var Compensators

A flexible AC Transmission Systems (FACTS) is a new technology offers a fast and reliable control over the transmission and distribution parameters like voltage and phase angle between the sending end voltage and receiving end voltage. Distribution static synchronous compensator (DSTATCOM) is a second generation member of the (FACTS) controllers. Reactive power compensation is an important aspect in the control of distribution systems. Reactive current in addition to increasing the distribution system losses, introduces voltage drop at lead point and finally it causes poor power quality in power systems. Primary radial distribution feeders have high resistance to reactance ratio, which causes voltage drop and high power loss in radial distribution systems. providing high demanding power to entire load while maintaining voltage magnitude at acceptable range is one of the major system constraints, using of capacitor banks to improve the reactive power have not quite enough at high reactive power feeder, because it have more slow in step by step response and have not capable to generate continuously variable reactive power. In some primary distribution feeders at the state of Khartoum, it is observed that there are some appropriate drops in voltage and quality service at high reactive power loads although some individual capacitor banks have been connected at these feeders, from here we researched for a new technology to overcome this problem. A steady-state model of (DSTATCOM) is proposed and developed to compensate the reactive power by using a Voltage Source Converter (VSC) with Pulse Width Modulation (PWM) and cascade control of four direct proportional integral controllers (PI) in synchronous reference frame. The detailed modeling and control design of (DSTATCOM) with specific typical radial primary distribution feeders (industrial, commercial, residential) are presented and implemented along necessary mathematical model equations in the Matlab software. Simulation schemes of (DSTATCOM) are done with help of control block diagrams and stability analysis. Load flow is an important method for analysis, operation and planning studies of any power system in a steady-state condition. In this research backward forward sweeps load flow method (Kirchhoff’s Laws) has been proposed rather than Newton-Raphson and Fast decoupled methods because the distribution feeders have a high R/X ratio which make the systems are ill-conditioned iterations analysis. (DSTATCOM) was installed on specific typical radial feeders at the (DSTATCOM) which using for distribution lines and load compensation has been the subject of considerable interest beside it is a new technology for a good power quality solution. Keywords: Power System, Flexible AC Transmission Systems (FACTS) Devices, STATCOM, PI Controller DOI: 10.7176/ISDE/13-1-05 Publication date:May 31st 202

An Explorative Study On Pharmaceutical Care Practice From The Perspective Of Pharmacists In Malaysia [RM300. B114 2008 f rb].

Objektif kajian ini adalah untuk meneroka dan mengumpul informasi dasar yang diperlukan untuk melaksanakan praktis penjagaan farmaseutikal (PC) di Malaysia. The objectives of this research were to explore and gather baseline information that is necessary for the implementation of pharmaceutical care (PC) practice in Malaysia

Numerical study of the characteristics of CNG, LPG and Hydrogen turbulent premixed flames

Numerical simulations have proven itself as a significant and powerful tool for accurate prediction of turbulent premixed flames in practical engineering devices. The work presented in this thesis concerns the development of simulation techniques for premixed turbulent combustion of three different fuels, namely, CNG, LPG and Hydrogen air mixtures. The numerical results are validated against published experimental data from the newly built Sydney combustion chamber. In this work a newly developed Large Eddy Simulation (LES) CFD model is applied to the new Sydney combustion chamber of size 50 x 50 x 250 mm (0.625 litre volume). Turbulence is generated in the chamber by introducing series of baffle plates and a solid square obstacle at various axial locations. These baffles can be added or removed from the chamber to adapt various experimental configurations for studies. This is essential to understand the flame behaviour and the structure. The LES numerical simulations are conducted using the Smagorinsky eddy viscosity model with standard dynamic procedures for sub-grid scale turbulence. Combustion is modelled by using a newly developed dynamic flame surface density (DFSD) model based on the flamelet assumption. Various numerical tests are carried out to establish the confidence in the LES based combustion modelling technique. A detailed analysis has been carried out to determine the regimes of combustion at different stages of flame propagation inside the chamber. The predictions using the DFSD combustion model are evaluated and validated against experimental measurements for various flow configurations. In addition, the in-house code capability is extended by implementing the Lewis number effects. The LES predictions are identified to be in a very good agreement with the experimental measurements for cases with high turbulence levels. However, some disagreement were observed with the quasi-laminar case. In addition a data analysis for experimental data, regarding the overpressure, flame position and the flame speed is carried out for the high and low turbulence cases. Moreover, an image processing procedure is used to extract the flame rate of stretch from both the experimental and numerical flame images that are used as a further method to validate the numerical results. For the grids under investigation, it is concluded that the employed grid is independent of the filter width and grid resolution. The applicability of the DFSD model using grid-independent results for turbulent premixed propagating flames was examined by validating the generated pressure and other flame characteristics, such as flame position and speed against experimental data. This study concludes that the predictions using DFSD model provide reasonably good results. It is found that LES predictions were slightly improved in predicting overpressure, flame position and speed by incorporating the Lewis number effect in the model. Also, the investigation demonstrates the effects of placing multiple obstacles at various locations in the path of the turbulent propagating premixed flames. It is concluded that the pressure generated in any individual configuration is directly proportional to the number of baffles plates. The flame position and speed are clearly dependent on the number of obstacles used and their blockage ratio. The flame stretch extracted from both the experimental and numerical images shows that hydrogen has the highest stretch values over CNG and LPG. Finally, the regime of combustion identified for the three fuels in the present combustion chamber is found to lie within the thin reaction zone. This finding supports the use of the laminar flamelet modelling concept that has been in use for the modelling of turbulent premixed flames in practical applications

Patient preference and satisfaction in erectile dysfunction therapy: a comparison of the three phosphodiesterase-5 inhibitors sildenafil, vardenafil and tadalafil

Erectile dysfunction (ED) is a problem that may affect up to 52% of men between the ages of 40 and 70. It can be distressing because of its negative effect on self-esteem, quality of life, and interpersonal relationships. Oral phosphodiesterase-5 inhibitors (PDE5 inhibitors) are now the first choice of treatment in ED. The availability of three (sildenafil citrate, tadalafil, and vardenafil) well tolerated and effective oral PDE5 inhibitors gives treatment options for men with ED. Although the mechanism of action is the same for the three drugs, they differ in their pharmacokinetics. Several preference studies were conducted between the three PDE5 inhibitors but they were not free from bias. Because of the lack of overwhelming reliable data showing that one PDE5 inhibitor is superior to another, current opinion is that the individual patient should have the opportunity to test all three drugs and then select the one that best suits him and his partner

Analytical Study of the Status of Renewable Energy Source and its Efficiency: Future Prospects

Electric energy security is fundamental, yet the high cost and restricted wellsprings of petroleum products, notwithstanding the need to lessen nursery gasses outflow, have made inexhaustible assets appealing in world energy based economies. The potential for renewable power source assets is huge in light of the fact that they can, on a basic level, exponentially surpass the world's energy request; in this way, these sorts of assets will have a noteworthy offer later on worldwide energy portfolio, quite a bit of which is currently focusing on propelling their pool of renewable power source assets. Likewise, this paper presents how renewable power source assets are as of now being utilized and its efficiency, logical advancements to enhance their utilization, as well as its future prospects. This study is based on reviewing the past studies that relates to this study issue to achieve the study goals. It found that a number of the countries have incredible renewable power source potential and is quick to diminish its reliance on petroleum derivatives by expanding its utilization of renewable power source assets. It additionally found that the wind area is a decent case of the expanding enthusiasm for era of power with inexhaustible assets. Later on, it anticipated that would build the reception renewable power source assets all through the world, and improve its energy capacity and efficiency. It concluded that renewable power source gives gigantic advantages and can contribute altogether in the national energy blend at any rate monetary, ecological and social expenses and it is normal that the offer of renewable power source in the aggregate era limit will increment in future. Keywords: energy, renewable energy, electric energy, energy sources, energy efficienc

Treatment of Peyronie's Disease With Collagenase Clostridium histolyticum and Vacuum Therapy: A Randomized, Open-Label Pilot Study

BACKGROUND: Collagenase Clostridium histolyticum (CCH) is indicated for the treatment of penile curvature in adult men with Peyronie's disease (PD) with palpable plaque and curvature deformity of at least 30° at the start of therapy. AIM: To evaluate the efficacy and safety of CCH plus vacuum-pump therapy with and without penile modeling for the management of PD. METHODS: Adult men with PD and penile curvature of at least 30° were randomly assigned to receive CCH 0.58 mg plus vacuum therapy alone (n = 15) or with penile plaque modeling (n = 15). Patients received no more than four treatment cycles (cycle = ∼6-week duration), each consisting of two intralesional injections of CCH administered 24 to 72 hours apart. Vacuum therapy was applied twice daily from 14 days after the second injection of each cycle until the following cycle. Modeling was performed 24 to 72 hours after the second injection of each cycle. OUTCOMES: The primary end point was change in penile curvature from baseline to week 36; additional end points included changes in Peyronie's Disease Questionnaire (PDQ) domain scores, composite response (≥20% decrease in penile curvature and decrease in PDQ bother score ≥ 1 point), and global response (small but important, moderate, or much improvement in the Global Assessment of PD). RESULTS: At week 36, improvement in penile curvature from baseline was similar in the two groups (mean change from baseline = -23.7° [SD = 10.9] for CCH + vacuum + modeling and -23.3° [SD = 7.2] for CCH + vacuum; between-group difference = -0.3°, 95% CI = -7.3 to 6.6). Improvements in most PDQ domains, including bother, were observed from baseline to week 36 in the two groups. Most patients were composite (66.7% and 84.6% with CCH + vacuum + modeling and CCH + vacuum, respectively) and global (86.7% and 92.3%, respectively) responders. The most common adverse events were penile contusion, penile swelling, and penile pain. CLINICAL IMPLICATIONS: Vacuum-pump therapy administered alone or in combination with modeling after CCH treatment could improve PD symptoms. STRENGTHS AND LIMITATIONS: This was a pilot study with a small sample and limited follow-up duration. CONCLUSION: CCH and vacuum-pump therapy (alone or combined with modeling) could be an appropriate consideration for men with PD and warrants further investigation