196,603 research outputs found
Partiti politici e dimensione costituzionale della libertà associativa
No full textLa collocazione costituzionale del partito politico nella democrazia rappresentativa. La crisi della rappresentanza politica e della forma partito. La democrazia interna ai partiti e le forme di finanziament
Comment on “Pore water flow due to near-bed turbulence and associated solute transfer in a stream or lake sediment bed" by M. Higashino et al.
No full textFDI Determination and Corporate Tax Competition in a Volatile World
No full textThis paper investigates the impact of economic and political volatility on corporate tax rates on a large dataset of countries over the 1983–2003 period. Estimation of a dynamic tax rate equation supports the hypothesis that economic volatility
negatively affects statutory corporate tax rates, while political volatility has no significant effect. In order to identify the channels through which volatility works, we estimate a structural model allowing for simultaneous determination of corporate tax rates and FDI inflows, and find that economic volatility affects the corporate tax setting process through its impact on FDI inflows
Effect of peritoneal fluid, follicular fluid, and their volumetric mixture on acrosomal reactivity in vitro.
No full textOBJECTIVE:
To determine the effects of peritoneal and follicular fluids (PFs, FFs) on sperm acrosomal reaction (AR).
DESIGN:
Prospective, randomized study.
SETTING:
Three hospital-based infertility units.
PATIENTS:
Twenty-three women participating in GIFT programs; 23 men participating in AIH programs.
INTERVENTIONS:
Hormonal stimulation after buserelin desensitation; laparoscopy 36 hrs after hCG injection.
MAIN OUTCOME MEASURE:
Percentage of acrosomally-reacted sperm.
RESULTS:
Compared with Earle's medium (control), moderate but significant increases of ARs were observed as function 1) of the relative content of FF in the incubation medium and 2) as function of time (these increases were constantly lower than those registered for the respective positive control, i.e. 2x frozen/thawed sperm). In contrast, when PF alone was present in the incubation medium, no such effects on AR were registered.
CONCLUSIONS:
FF and mixtures of PF and FF--but not PF alone--seem to induce some rapid and time-dependent processes which finally lead to an AR. Therefore, and independently on the infertility cause (tubal, male-dependent, unexplained infertility), PF seems able to exert effects on sperm motility (Revelli et al., Fertil. Steril 57, 654-60 [1992]) while maintaining an unreacted sperm status
Performance Optimization of Overshot Water Wheels at High Rotational Speeds for Hydropower Applications
No full textOvershot water wheels are hydropower converters generally employed for head differences up to 6 m and maximum flow rates of
150−200 L=s per meter width. The maximum hydraulic efficiency (80%–85%) is constant for rotational speeds below the critical speed, whereas the efficiency linearly decreases at higher rotational speeds due to the increase of water losses at the inflow. To improve the efficiency when the rotational speed is above the critical speed, an improved geometric design was investigated by implementing a theoretical model validated using experimental results. The new geometry consists of a circular wall around the periphery of overshot water wheels. The wall redirects into the buckets the water flow that is lost at the inflow, improving the efficiency up to 1.5 times at high rotational speeds
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