Choosing high-equity cosmetic brands in bad macroeconomic conditions: evidence from panel data

PurposeThis study investigates how price, promotion and consumer characteristics affect consumer choice of high over medium- and low-equity cosmetic brand under different macroeconomic conditions.Design/methodology/approachThe study uses purchase records from MarketingScan's Behaviour Scan panels (a GFK – Mediametrie Company) covering the period from 2008 to 2009. The panel analysed represents a sample of 2,149 households representative of the national population.FindingsResults indicate that regular price and relative brand price increase high-equity cosmetic brand choice over both low- and medium-equity brands, while reference price decreases it. Brand feature promotion activity and joint promotion positively affect high-equity cosmetic brand choice, whereas display promotion decreases it. In comparison to medium-equity cosmetic brands, gender and education slightly increase high-equity cosmetic brand choice, while age decreases it. Surprisingly, household income does not affect high-equity cosmetic brand choice. The effect of regular price decreases over worsening macroeconomic conditions. However, the effect of relative brand price decreases between low and moderate contraction periods, but increases between moderate and high contraction times. Feature promotion is effective only when the contraction is moderate, while the negative effect of display promotion is stable over time.Originality/valueThe paper underlines the moderating role of macroeconomic conditions on the relationship between pricing decisions as well as promotion activity and consumer choice of high-equity cosmetic brands.

Breaking the centrifugal barrier to giant planet contraction by magnetic disc braking

ABSTRACT During the runaway phase of their formation, gas giants fill their gravitational spheres of influence out to Bondi or Hill radii. When runaway ends, planets shrink several orders of magnitude in radius until they are comparable in size to present-day Jupiter; in 1D models, the contraction occurs on the Kelvin–Helmholtz time-scale tKH, which is initially a few thousand years. However, if angular momentum is conserved, contraction cannot complete, as planets are inevitably spun up to their breakup periods Pbreak. We consider how a circumplanetary disc (CPD) can de-spin a primordially magnetized gas giant and remove the centrifugal barrier, provided the disc is hot enough to couple to the magnetic field, a condition that is easier to satisfy at later times. By inferring the planet’s magnetic field from its convective cooling luminosity, we show that magnetic spin-down times are shorter than contraction times throughout post-runaway contraction: tmag/tKH ∼ (Pbreak/tKH)1/21 ≲ 1. Planets can spin-down until they corotate with the CPD’s magnetospheric truncation radius, at a period Pmax/Pbreak ∼ (tKH/Pbreak)1/7. By the time the disc disperses, Pmax/Pbreak ∼ 20–30; further contraction at fixed angular momentum can spin planets back up to ∼10Pbreak, potentially explaining observed rotation periods of giant planets and brown dwarfs.

Architectural and functional specifics of the human triceps surae muscle in vivo and its adaptation to microgravity

Long-term exposure to microgravity (μG) is known to reduce the strength of a skeletal muscle contraction and the level of general physical performance in humans, while little is known about its effect on muscle architecture. Architectural and contractile properties of the triceps surae (TS) muscle were determined in vivo for male cosmonauts in response ( n = 8) to a spaceflight (213.0 ± 30.5 days). The maximal voluntary contraction (MVC), tetanic tension ( Ро), and voluntary and electrically evoked contraction times and force deficiency (Pd) were determined. The ankle was positioned at 15° dorsiflexion (−15°) and 0, 15, and 30° plantar flexion, with the knee set at 90°. At each position, longitudinal ultrasonic images of the medial (MG) and lateral (LG) gastrocnemius and soleus (SOL) muscles were obtained while the subject was relaxed. After a spaceflight, MVC and Pо decreased by 42 and 26%, respectively, and Pd increased by 50%. The rate of tension of a voluntary contraction substantially reduced but evoked contractions remained unchanged. In the passive condition, fiber length ( Lf) changed from 43, 57, and 35 mm (knee, 0°; ankle, −15°) to 34, 38, and 25 mm (knee, 0°; ankle, 30°) for MG, LG, and SOL, respectively, and Θf changed from 27, 21, and 23° (knee, 0°; ankle, −15°) to 43, 29, and 34° (knee, 0°; ankle, 30°) for MG, LG, and SOL, respectively. Different Lf and Θf, and their changes after spaceflight, might be related to differences in force-producing capabilities of the muscles and elastic characteristics of tendons and aponeuroses. NEW & NOTEWORTHY The present work was the first to combine measuring the fiber length and pennation angle (ultrasound imaging) as main determinants of mechanical force production and evaluating the muscle function after a long-duration spaceflight. The results demonstrate that muscles with different functional roles may differently respond to unloading, and this circumstance is important to consider when planning rehabilitation after unloading of any kind, paying particular attention to postural muscles.

Gestational age at time of in utero lipopolysaccharide exposure influences the severity of inflammation-induced diaphragm weakness in lambs

The preterm diaphragm is functionally immature compared with its term counterpart. In utero inflammation further exacerbates preterm diaphragm dysfunction. We hypothesized that preterm lambs are more vulnerable to in utero inflammation-induced diaphragm dysfunction compared with term lambs. Pregnant ewes received intra-amniotic (IA) injections of saline or 10 mg lipopolysaccharide (LPS) 2 or 7 days before delivery at 121 days (preterm) or ∼145 days (term) of gestation. Diaphragm contractile function was assessed in vitro. Plasma cytokines, diaphragm myosin heavy chain (MHC) isoforms, and oxidative stress were evaluated. Maximum diaphragm force in preterm control lambs was significantly lower (22%) than in term control lambs ( P < 0.001). Despite similar inflammatory cytokine responses to in utero LPS exposure, diaphragm function in preterm and term lambs was affected differentially. In term lambs, maximum force after a 2-day LPS exposure was significantly lower than in controls (by ~20%, P < 0.05). In preterm lambs, maximum forces after 2-day and 7-day LPS exposures were significantly lower than in controls (by ~30%, P < 0.05). Peak twitch force after LPS exposure was significantly lower in preterm than in controls, but not in term lambs. In term lambs, LPS exposure increased the proportion of MHC-I fibers, increased twitch contraction times, and increased fatigue resistance relative to controls. In preterm diaphragm, the cross-sectional area of embryonic MHC fibers was significantly lower after 7-day versus 2-day LPS exposures. We conclude that preterm lambs are more vulnerable to IA LPS-induced diaphragm dysfunction than term lambs. In utero inflammation exacerbates diaphragm dysfunction and may increase susceptibility to postnatal respiratory failure.

Assessment of the strength of the lower limb muscles in subjects with stroke with portable dynamometry: a literature review

Introduction: Weakness of the lower limb muscles, which are the main impairments after stroke, is associated with reduced mobility and decreased performance in functional tasks. Therefore, the assessment of strength of these muscles is necessary, which is commonly assessed with portable dynamometry. Aims: To perform a literature review regarding the methods used to assess lower limb strength with portable dynamometry in subjects with stroke and to describe its investigated measurement properties with this population. Materials and Methods: An extensive search was performed on the MEDLINE, SCIELO, LILACS, and PEDro databases, by combining specific key words, followed by active manual search by two independent researchers. Results and Discussion: Thirty studies were included, and the muscular groups of the knee (90%) were the most assessed, followed by the ankle (66.7%) and hip (63.3%) joints. In 5% of the studies, there were not reported any descriptions related to the positioning of the subjects and the equipment, neither regarding the stabilization procedures. Only 50% provided information regarding the number of trials and only 46.7% regarding the contraction times, being three trials and 5s the most commonly applied. Only 10% provided feedback and 23.3% demonstrations, prior to data collection. Only seven studies (23.3%) investigated the measurement properties of portable dynamometry and reported moderate to high reliability levels. Final Considerations: The protocols used for the assessment of the strength of the lower limb muscles with portable dynamometry in subjects with stroke were not standardized. Moreover, only one measurement property was investigated: the reliability, which was considered adequate.

Myostatin dysfunction impairs force generation in extensor digitorum longus muscle and increases exercise-induced protein efflux from extensor digitorum longus and soleus muscles

Myostatin dysfunction promotes muscle hypertrophy, which can complicate assessment of muscle properties. We examined force generating capacity and creatine kinase (CK) efflux from skeletal muscles of young mice before they reach adult body and muscle size. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of Berlin high (BEH) mice with dysfunctional myostatin, i.e., homozygous for inactivating myostatin mutation, and with a wild-type myostatin (BEH+/+) were studied. The muscles of BEH mice showed faster (P < 0.01) twitch and tetanus contraction times compared with BEH+/+ mice, but only EDL displayed lower (P < 0.05) specific force. SOL and EDL of age-matched but not younger BEH mice showed greater exercise-induced CK efflux compared with BEH+/+ mice. In summary, myostatin dysfunction leads to impairment in muscle force generating capacity in EDL and increases susceptibility of SOL and EDL to protein loss after exercise.

Regenerated soleus muscle shows reduced creatine kinase efflux after contractile activity in vitro

Regenerated skeletal muscles show less muscle damage after strenuous muscle exercise. The aim of the studies was to investigate if the regeneration is associated with reduced muscle creatine kinase (CK) efflux immediately after the exercise. Cryolesion was applied to the soleus muscle of 3-month-old C57BL/6J male mice. Then total CK efflux was assessed in vitro in the regenerated muscles without exercise or after 100 eccentric contractions. The same measurements were performed in the control muscles, which were not exposed to cryolesion. Regenerated muscles generated weaker (P < 0.05) twitches, but stronger (P < 0.05) 150-Hz and 300-Hz tetani with prolonged (P < 0.01) contraction times compared with the control muscles. There was no difference between regenerated and control muscles in the total CK efflux without exercise, but only control muscles showed an increase (P < 0.001) in the CK efflux after the exercise. Our results suggest that muscle regeneration is associated with modulation of contractile properties and improvement in muscle resistance to damage after eccentric exercise.

Dynamic changes of twitchlike responses to successive stimuli studied by decomposition of motor unit tetanic contractions in rat medial gastrocnemius

Unfused tetanic contractions evoked by trains of stimuli at variable interpulse intervals (IPIs) were recorded for 10 fast fatigable (FF), 10 fast resistant (FR), and 10 slow (S) motor units (MUs) and subsequently decomposed with a mathematical algorithm into trains of twitch-shape responses to successive stimuli. The mean stimulation frequencies were matched for each MU to evoke tetani of similar fusion degrees, whereas the variability range of IPIs was in each case 50–150% of the mean IPI. Force and time parameters of decomposed twitches were analyzed and related to the first response. Considerable variability of the analyzed twitch parameters was observed in each MU, although the largest range of variability occurred in slow MUs. In general, the decomposed twitch responses had longer duration and higher force than single-twitch contractions, although for nine FF and six FR MUs some of the decomposed responses were slightly weaker (but not faster) than the first twitches of these MUs. Comparison of the strongest decomposed twitch to the first decomposed twitch revealed ratios of forces up to 2.35, 3.33, and 6.89 for FF, FR, and S MUs and ratios of force-time areas up to 3.54, 4.67, and 14.26 for FF, FR, and S MUs, whereas for the contraction times the ratios of the longest decomposed twitch to the first twitch amounted to 2.46, 2.07, and 3.52 for FF, FR, and S MUs, respectively. The results indicate that contractile responses to successive action potentials are considerably variable, especially for slow MUs.

Discharge properties of motor units during steady isometric contractions performed with the dorsiflexor muscles

The purpose of this study was to record the discharge characteristics of tibialis anterior motor units over a range of target forces and to import these data, along with previously reported observations, into a computational model to compare experimental and simulated measures of torque variability during isometric contractions with the dorsiflexor muscles. The discharge characteristics of 44 motor units were quantified during brief isometric contractions at torques that ranged from recruitment threshold to an average of 22 ± 14.4% maximal voluntary contraction (MVC) torque above recruitment threshold. The minimal [range: 5.8–19.8 pulses per second (pps)] and peak (range: 8.6–37.5 pps) discharge rates of motor units were positively related to the recruitment threshold torque ( R2 ≥ 0.266; P < 0.001). The coefficient of variation for interspike interval at recruitment was positively associated with recruitment threshold torque ( R2 = 0.443; P < 0.001) and either decreased exponentially or remained constant as target torque increased above recruitment threshold torque. The variability in the simulated torque did not differ from the experimental values once the recruitment range was set to ∼85% MVC torque, and the association between motor twitch contraction times and peak twitch torque was defined as a weak linear association ( R2 = 0.096; P < 0.001). These results indicate that the steadiness of isometric contractions performed with the dorsiflexor muscle depended more on the distributions of mechanical properties than discharge properties across the population of motor units in the tibialis anterior.

Tissue Doppler imaging in rheumatic carditis

ObjectiveOur study was undertaken to assess cardiac functions by tissue Doppler echocardiography in patient with primary episode of rheumatic carditis.MethodsWe divided 82 patients with rheumatic carditis were divided in two groups; 50 patients with mild and 32 patients with mitral regurgitation of grade two or more. A control group consisted of 30 healthy children free of any disease. All children underwent conventional and tissue Doppler echocardiography initially and at the time of the follow-up examination.ResultsMyocardial systolic wave velocity of the mitral annulus was significantly higher in patients with mitral regurgitation of grade two or more when compared to the control group, but was not different between patients with mild mitral regurgitation and healthy subjects at the time of the initial attack. Myocardial precontraction time, myocardial contraction time, and the ratio of myocardial precontraction and contraction times were significantly prolonged, and the systolic myocardial velocity of the mitral annulus was significantly decreased in patients with mitral regurgitation of grade two or more at the time of the follow-up examination. The myocardial systolic wave velocity was significantly lower, and myocardial precontraction time, myocardial contraction time, and the ratio of the precontraction and contraction times, were significantly longer or greater between patients with grade two or more mitral regurgitation and the control group at follow-up examination.ConclusionWe detected subclinical systolic dysfunction of the left ventricle in children with a primary episode of rheumatic carditis due to ongoing ventricular volume overload. Tissue Doppler imaging provides a quantifiable indicator useful for cardiac monitoring of disease during the period of follow up.