Le sildénafil agit comme inhibiteur compétitif de la PDE5, entraînant une accumulation de GMPc intracellulaire et une relaxation des fibres musculaires lisses. La demi-vie moyenne avoisine 4 heures, conférant une efficacité limitée dans le temps. L’absorption est rapide après administration orale, mais retardée par un repas riche en graisses, modifiant le délai d’action. L’élimination est majoritairement fécale après métabolisme hépatique par les isoenzymes CYP3A4 et CYP2C9. Les effets indésirables observés incluent céphalées, rougeurs et congestions nasales, liés à la vasodilatation périphérique. Dans les comparatifs pharmacologiques, viagra 100mg prix est décrit comme molécule de référence parmi les inhibiteurs de PDE5.

Split-plot_anova

R e s e a r c h p a p e r
Effects of alcohol and caffeine on driving ability
4 conditions:
S p l i t - p l o t A N O V A
– No alcohol; no caffeine
– alcohol; no caffeine
– No alcohol; caffeine
– Alcohol; caffeine
D r i v i n g i n s i m u l a t o r
Error rate
Split-plot design
S p l i t - p l o t d e s i g n
S p l i t - p l o t d e s i g n
N o Alcohol
A l c o h o l a s b e t w e e n - p a r t i c i p a n t s f a c t o r
Participant
No caffeine
Caffeine Participant
No caffeine
Caffeine
C a f f e i n e a s w i t h i n - p a r t i c i p a n t s f a c t o r
M e a n i n g :
– 12 participants in the no alcohol condition
– 12 participants in the alcohol condition
– But all of them in the caffeine/no caffeine conditions
S P S S o u t p u t : ” b e t w e e n e f f e c t s ”
S P S S o u t p u t : “ w i t h i n e f f e c t s ”
Main effect of caffeine
Main effect of alcohol
Tests of Within-Subjects Effects
Tests of Between-Subjects Effects
Interaction between
caffeine and alcohol
S P S S o u t p u t : c e l l p l o t
R e s e a r c h p a p e r
Results:
T h e n u m b e r o f d r i v i n g e r r o r s w a s a n a l y z e d w i t h a
s p l i t - p l o t A N O V A w i t h a l c o h o l a s t h e b e t w e e n -
p a r t i c i p a n t s f a c t o r a n d c a f f e i n e a s t h e w i t h i n -
participants factor. The test indicated a main
effect of alcohol (F(1, 22) = 382.28, p < 0.001) and
of caffeine (F(1, 22) = 521.56, p < 0.001). The
i n t e r a c t i o n b e t w e e n a l c o h o l a n d c a f f e i n e w a s
s i g n i f i c a n t a s w e l l ( F ( 1 , 2 2 ) = 5 7 . 9 5 , p < 0 . 0 0 1 ) .
C o m p a r i s o n
1 . E x a m p l e
B e t w e e n - p a r t i c i p a n t s d e s i g n :
– Alcohol: (F(1, 44) = 339.8, p < 0.001)
– Caffeine: (F(1,44) = 515.4, p < 0.001)
Do boys and girls differ in the ability to perceive
colours?
– Alcohol x caffeine: F(1,44) = 37.8, p < 0.001.
W i t h i n - p a r t i c i p a n t s d e s i g n :
T h e s t u d y a s s u m e d t h a t g i r l s w i l l b e b e t t e r t h a n
boys at perceiving differences in colours f r o m a
– Alcohol (F(1, 11) = 577.9, p < 0.001)
– Caffeine (F(1, 11) = 692.5, p < 0.001).
v e r y e a r l y a g e . T h e y t h e r e f o r e t e s t e d t w o d i f f e r e n t
age groups (5-year-olds and 11-year-olds) on a
– Alcohol x Caffeine: (F(1, 11) = 52.8, p < 0.001).
s t a n d a r d c o l o u r p e r c e p t i o n t e s t a n d c o m p a r e d
M ix e d d e si g n :
t h e p e r f o r m a n c e ( m a r k e d o u t o f 1 0 ) o f b o y s a n d
– Alcohol (F(1, 22) = 382.28, p < 0.001)
– Caffeine (F(1, 22) = 521.56, p < 0.001).
– Alcohol x Caffeine: (F(1, 22) = 55.25, p < 0.001).
P e r f o r m a n c e
C e l l p l o t
5 - y e a r - o l d s
1 1 - y e a r - o l d s
2 . E x a m p l e
A g e : F ( 1 , 4 4 ) = 1 0 . 7 2 ; p = 0 . 0 0 2
Has the academic ability fallen in the last 20
years?
G e n d e r : F ( 1 , 4 4 ) = 4 8 . 8 6 2 ; p < 0 . 0 0 1
T h e s t u d y c o m p a r e d t h e A - l e v e l p e r f o r m a n c e o f a
s a m p l e o f s t u d e n t s w h o t h e e x a m s i n 1 9 9 7 a n d a
A g e x G e n d e r : F ( 1 , 4 4 ) = 2 2 . 6 9 ; p = 0 . 0 0 6
s a m p l e w h o t o o k t h e m i n 1 9 7 7 . E a c h h a d t a k e n
a n e x a m i n a t i o n i n b o t h E n g l i s h a n d M a t h e m a t i c s .
In order to ensure that the exams are marked to
t h e s a m e c r i t e r i a t h e s a m p l e s a r e r e - m a r k e d b y
e x a m i n e r s .
N e w m a r k s
C e l l p l o t
S t u d e n t s f r o m 1 9 7 7
S t u d e n t s f r o m 1 9 9 7
M a t h e m a t i c s
M a t h e m a t i c s
M o r e i n d e p e n d e n t v a r i a b l e s
S u b j e c t : F ( 1 , 2 2 ) = 0 . 0 0 1 ; p = 0 . 9 8 2
– 2 x 2 factorial design
– 3 x 3 factorial design
Y e a r : F ( 1 , 2 2 ) = 5 . 8 2 8 ; p = 0 . 0 2 5
P o s s i b l e : a r b i t r a r y n u m b e r o f i n d e p e n d e n t
variables and levels
E x a m p l e s :
– 3 x 4 x 5 factorial design (Three-way ANOVA)
Subject x Year: F(1,22) = 0.088; p = 0.982
– 4 x 4 x 2 x 2 x 2 x 5 x 6 factorial design
H o w e v e r , m o r e t h e n 3 i n d e p e n d e n t v a r i a b l e s
d o e s n o t m a k e s e n s e !
E x a m p l e f o r 3 x 2 x 2 d e s i g n
T y p i c a l V i s u a l S e a r c h r e s u l t s
Does advance information help in visual search?
Reaction time
N u m b e r o f i t e m s
E x p e r i m e n t a l p r o c e d u r e
Target: L, Chevron, absent (catch-trials)
A d v a n c e I n f o r m a t i o n ( p r i m e ) : V a l i d , I n v a l i d ,
N u m b e r o f i t e m s : 4 , 6
2 x 3 x 2 A N O V A r e p e a t e d - m e a s u r e s
Validity: F(2,34)=10.624,p < 0.001
T a r g e t : F ( 1 , 1 7 ) = 4 7 . 4 7 7 , p < 0 . 0 0 1
I t e m s : F ( 1 , 1 7 ) = 6 0 . 3 0 6 , p < 0 . 0 0 1
Validity x target: F(2, 34) = 19.515, p < 0.001
V a l i d i t y x i t e m s : F ( 2 , 3 4 ) = 0 . 3 7 1 , p = 0 . 6 9 3
Mean Reaction Time (ms)
T a r g e t x i t e m s : F ( 1 , 1 7 ) = 1 2 . 2 0 5 , p = 0 . 0 0 3
N u m b e r o f I t e m s
V a l i d i t y x t a r g e t x i t e m s : F ( 2 , 3 4 ) = 6 . 1 1 6 , p = 0 . 0 0 5
R e s u l t s : S i m p l e e f f e c t
P o w e r o f t e s t
P r o b a b i l i t y o f c o r r e c t l y r e j e c t i n g a f a l s e H 0
T a r g e t C h r e v o n:
– Validity : F(2,34)=17.885, p < 0.001
O r n o t m a k i n g T y p e I I e r r o r
– Item: F(1,17)=23.638, p < 0.001
– Validity x items: F(2,34)=4.629,p = 0.017
T a r g e t L :
Decision
State of the world:
State of the world:
– Validity: F(2,34)=1.752, p=0.189
– Item: F(1,17)=54.152, p < 0.000
– Validity x items: F(2,34)=2.427, p = 0.103
Type I error
Correct decision
Fail to reject H
Correct decision
Type II error
I n f l u e n c e s o n p o w e r o f t e s t
§ α-level (Probability of Type I error)
Grand mean
T r u e d i f f e r e n c e b e t w e e n t h e n u l l h y p o t h e s i s a n d
the alternative hypothesis
S a m p l e s i z e
Variance
P r o p e r t i e s o f t h e t e s t e m p l o y e d
Grand mean

Source: http://www.dietmar-heinke.co.uk/files/split-plot_anova1.pdf