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We propose an experimental analogy to verify Kepler's second law using a spherical pendulum. We made a movie of a closed elliptical orbit of the pendulum and extracted the data position using the Tracker software. Analyzing the data, we measured the areas that the position vector sweeps showing the validity of Kepler's second law.

As an extension to our work on intramolecular annulations via silyloxycyclopropane derived anions, we have investigated the chemistry of cyclopentyl cyclopropane systems, 6-9, in an effort to prepare stereospecifically functionalized hydrindenones. The intramolecular closures of the cyclopropane-derived anions were less stereoselective and more complicated than the corresponding cyclohexyl systems. Nevertheless, modest yields of isomeric hydrinenones such as 20 and 21 were obtained as well as several products derived from a prototropic shift to form the cyclopentanone enolates. These latter products possessed the 5,5-pentalenone systems, 22 and 23.

A straightforward stereospecific synthesis of two stereoisomers, (4R, 8S) and (4S, 8S), of 4,8-dimethyldecanal (1), out of four possible isomers, is described. The key step employs the coupling reaction of tosylates (3) and (3a), which are obtained from (R)- and (S)- citronellol, with the chiral Grignard reagent prepared from comercial (S)-(+)-1-bromo-2-methylbutane (4).

The article discusses the evolutionary origins for artist propensities in human beings, including in regard to the role that sexual selections plays in this regard. An overview of the role of the male and female in reproduction, including in regard to the contention that in biological evolution, reproduction is primarily a maternal function, is provided.

This study investigated the chronic effects of concurrent training (CT) on morphological and molecular adaptations. 37 men (age = 23.7 ± 5.5 year) were divided into 4 groups: interval (IT), strength (ST) and concurrent (CT) training and a control group (C) and underwent 8 weeks of training. Maximum strength (1RM) and muscle cross-sectional area (CSA) were evaluated before and after training. Muscle samples were obtained before the training program and 48 h after the last training session. VO 2max improved in 5 ± 0.95 % and 15 ± 1.3 % (pre- to post-test) in groups CT and IT, respectively, when compared to C. Time to exhaustion (TE) improved from pre- to post-test when compared to C (CT = 6.1 ± 0.58 %; IT = 8.3 ± 0.88 %; ST = 3.2 ± 0.66 %). 1RM increased from pre-to post-test only in ST and CT groups (ST = 18.5 ± 3.16 %; CT = 17.6 ± 3.01 %). Similarly, ST and CT groups increased quadriceps CSA from pre-to post-test (6.2 ± 1.4 %; 7.8 ± 1.66 %). The p70S6K1 total protein content increased after CT. The ST group showed increased Akt phosphorylation at Ser473 (45.0 ± 3.3 %) whereas AMPK phosphorylation at Thr172 increased only in IT group, (100 ± 17.6 %). In summary, our data suggest that despite the differences in molecular adaptations between training regimens, CT did not blunt muscle strength and hypertrophy increments when compared with ST. [ABSTRACT FROM AUTHOR]

The cellular mechanisms of positive effects associated with aerobic exercise training on overall intrinsic skeletal muscle changes in heart failure (HF) remain unclear. We investigated potential Ca2+ abnormalities in skeletal muscles comprising different fiber composition and investigated whether aerobic exercise training would improve muscle function in a genetic model of sympathetic hyperactivity induced HF. A cohort of male 5-mo-old wild-type (WT) and congenic α2A/α2C adrenoceptor knockout (ARKO) mice in a C57BL/6J genetic background were randomly assigned into untrained and trained groups. Exercise training consisted of a 8-wk running session of 60 min, 5 days/wk (from 5 to 7 mo of age). After completion of exercise training protocol, exercise tolerance was determined by graded treadmill exercise test, muscle function test by Rotarod, ambulation and resistance to inclination tests, cardiac function by echocardiography, and Ca2+ handling-related protein expression by Western blot. α2A/α2CARKO mice displayed decreased ventricular function, exercise intolerance, and muscle weakness paralleled decreased expression of sarcoplasmic Ca2+ release-related proteins [α1, α2, and β1-subunits of dihydropyridine receptor (DHPR) a ryanodine receptor (RyR)] and Ca reuptake-related proteins [sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA)1/2 and N Ca2+ exchanger (NCX)] in soleus and plantaris. Aerobic exercise training significantly improved exercise tolerance and muscle function and reestablished the expression of proteins involved in sarcoplasmic Ca2+ handling toward WT levels. We provide evidence that Ca2+ handling-related protein expression is decreased in this HF model and that exercise training improves skeletal muscle function associate with changes in the net balance of skeletal muscle Ca2+ handling proteins. [ABSTRACT FROM AUTHOR]

The article is in response to a discussion started by University of York's Derek Hodgson in his article "The parasitic nature of 'art': response to Varella et al. and associated commentaries" in which he questioned the author's notion of sexual selection in prehistoric rock art. The article maintains its original claims about sexual selection and adaptive evolution and challenges Hodgson's understanding of art as a non-adaptive pleasure seeking activity.