Relationship between physical inactivity and adiposity in prepubertal boys.

OBJECTIVE: To study the relationship between the energy expenditure for activity (EEAct), the level of activity and adiposity in a group of 9-year-old boys (n = 28) with different body composition (body weight, 38 +/- 10 kg [range, 23 to 66 kg]; fat mass, 23% +/- 10% [range, 8% to 42%]). METHODS: Total energy expenditure (TEE) was measured by means of the heart-rate monitoring method. EEAct was calculated as TEE-(REE+0.1 TEE), where REE is the postabsorptive resting energy expenditure and 0.1 TEE corresponds to the postprandial thermogenesis (approximately 10% of TEE). RESULTS: TEE, REE, and EEAct were 9388 +/- 1859, 5154 +/- 642, and 3295 +/- 1356 l J/day, respectively. Daily time devoted to sedentary and nonsedentary activities averaged 290 +/- 155 minutes (range, 69 to 621) and 534 +/- 150 minutes (range, 180 to 783), respectively. Time spent on sedentary activities was directly proportional to fat mass percentage (r = 0.46; p < 0.05). It was the only variable, among the free-living physical-activity [EEAct, TEE/(REE+0.1 TEE) ratio, time spent in nonsedentary and sedentary activities] variables, which remained significantly in the multiple step-down regression analysis final equation (r = 0.46; p < 0.05). CONCLUSIONS: The positive relationship between adiposity and time spent on sedentary activities in 9-year-old boys suggests the importance of the role played by muscular activity, at least in the maintenance of obesity in childhood. Prepubertal children should be encouraged to spend less time on sedentary activities to treat and prevent their obesity.

Public health expenditure and spatial interactions in a decentralized national health system

One of the limitations of cross-country health expenditure analysis refers to the fact that the financing, the internal organization and political restraints of health care decision-making are country-specific and heterogeneous. Yet, a potential solution is to examine the influence of such effects in those countries that have undertaken decentralization processes. In such a setting, it is possible to examine potential expenditure spillovers across the geography of a country as well as the influence of the political ideology of regional incumbents on public health expenditure. This paper examines the determinants of public health expenditure within Spanish region-states (Autonomous Communities, ACs), most of them subject to similar financing structures although exhibiting significant heterogeneity as a result of the increasing decentralization, region-specific political factors along with different use of health care inputs, economic dimension and spatial interactions

Cost-Based Models of Economic Growth

In this paper we highlight the importance of the operational costs in explaining economic growth and analyze how the industrial structure affects the growth rate of the economy. If there is monopolistic competition only in an intermediate goods sector, then production growth coincides with consumption growth. Moreover, the pattern of growth depends on the particular form of the operational cost. If the monopolistically competitive sector is the final goods sector, then per capita production is constant but per capita effective consumption or welfare grows. Finally, we modify again the industrial structure of the economy and show an economy with two different growth speeds, one for production and another for effective consumption. Thus, both the operational cost and the particular structure of the sector that produces the final goods determines ultimately the pattern of growth.

Heterogeneous discounting in consumption-investment problems. Time consistent solutions

[cat] En aquest treball s'analitza un model estocàstic en temps continu en el que l'agent decisor descompta les utilitats instantànies i la funció final amb taxes de preferència temporal constants però diferents. En aquest context es poden modelitzar problemes en els quals, quan el temps s'acosta al moment final, la valoració de la funció final incrementa en comparació amb les utilitats instantànies. Aquest tipus d'asimetria no es pot descriure ni amb un descompte estàndard ni amb un variable. Per tal d'obtenir solucions consistents temporalment es deriva l'equació de programació dinàmica estocàstica, les solucions de la qual són equilibris Markovians. Per a aquest tipus de preferències temporals, s'estudia el model clàssic de consum i inversió (Merton, 1971) per a les funcions d'utilitat del tipus CRRA i CARA, comparant els equilibris Markovians amb les solucions inconsistents temporalment. Finalment es discuteix la introducció del temps final aleatori.

Public health expenditure and spatial interactions in a decentralized national health system

One of the limitations of cross-country health expenditure analysis refers to the fact that the financing, the internal organization and political restraints of health care decision-making are country-specific and heterogeneous. Yet, a potential solution is to examine the influence of such effects in those countries that have undertaken decentralization processes. In such a setting, it is possible to examine potential expenditure spillovers across the geography of a country as well as the influence of the political ideology of regional incumbents on public health expenditure. This paper examines the determinants of public health expenditure within Spanish region-states (Autonomous Communities, ACs), most of them subject to similar financing structures although exhibiting significant heterogeneity as a result of the increasing decentralization, region-specific political factors along with different use of health care inputs, economic dimension and spatial interactions

Acute alcohol consumption and injury: risk associations and attributable fractions for different injury mechanisms.

OBJECTIVE: Most studies on alcohol as a risk factor for injuries have been mechanism specific, and few have considered several mechanisms simultaneously or reported alcohol-attributable fractions (AAFs)-which was the aim of the current study. METHOD: Data from 3,592 injured and 3,489 noninjured patients collected between January 2003 and June 2004 in the surgical ward of the emergency department of the Lausanne University Hospital (Switzerland) were analyzed. Four injury mechanisms derived from the International Classification of Diseases, 10th Revision, were considered: transportation-related injuries, falls, exposure to forces and other events, and interpersonal violence. Multinomial logistic regression models were calculated to estimate the risk relationships of different levels of alcohol consumption, using noninjured patients as quasi-controls. The AAFs were then calculated. RESULTS: Risk relationships between injury and acute consumption were found across all mechanisms, commonly resulting in dose-response relationships. Marked differences between mechanisms were observed for relative risks and AAFs, which varied between 15.2% and 33.1% and between 10.1% and 35.9%, depending on the time window of consumption (either 6 hours or 24 hours before injury, respectively). Low and medium levels of alcohol consumption generally were associated with the most AAFs. CONCLUSIONS: This study underscores the implications of even low levels of alcohol consumption on the risk of sustaining injuries through any of the mechanisms considered. Substantial AAFs are reported for each mechanism, particularly for injuries resulting from interpersonal violence. Observation of a so-called preventive paradox phenomenon is discussed, and prevention or intervention measures are described.

The daily energy expenditure in stable chronic obstructive pulmonary disease.

Resting energy expenditure is frequently increased in chronic obstructive pulmonary disease (COPD), but it is unknown if this hypermetabolism holds true over 24 h. The aim of this study was to measure the actual 24-h energy expenditure (24-h EE) in patients with stable COPD. Energy expenditure was measured by indirect calorimetry, using a metabolic chamber for 24-h EE and a canopy for basal metabolic rate (BMR). Physical activity was detected in the chamber by a radar system, and its duration was quantified. Two groups matched for age and height were studied: 16 male ambulatory patients with stable COPD and 12 male normal subjects. Body weight was 92 +/- 12% of ideal body weight in the group with COPD and 108 +/- 11% in the control group (p = 0.01). BMR was 120 +/- 7% of predicted in the group with COPD and 108 +/- 12% in the control group (p < 0.01). However, 24-h EE was similar in the two groups, amounting to 1,935 +/- 259 kcal in patients with COPD and 2,046 +/- 253 kcal in the control group (NS). This corresponded to 145% and 137% of predicted BMR, and to 121% and 126% of measured BMR in patients with COPD and the control group, respectively (NS). Patients were allowed to pursue their usual treatment within the chamber, and a positive correlation existed between 24-h EE and the daily dose of inhaled beta 2-agonists (p < 0.03). During daytime, physical activity was lower in patients with COPD. This study shows that patients with stable COPD are characterized by a normal daily energy expenditure in controlled conditions in spite of an increased basal metabolic rate. They appear to save energy by reducing their spontaneous level of physical activity.

Reduced atrial emptying after orthotopic heart transplantation masquerading as restrictive transmitral Doppler flow pattern?

BACKGROUND: An elevated early (E) to late (A) diastolic filling velocities ratio, typically seen in advanced diastolic dysfunction, has also been observed after cardioversion of atrial fibrillation as a consequence of the depressed left atrial (LA) contractility. We hypothesized that the impaired LA contractile function demonstrated after orthotopic cardiac transplantation (OCT) could also lead to this "pseudorestrictive" pattern. METHOD: E/A ratio related to the tissue Doppler early mitral annular velocity (Ea) as preload-independent index of LV relaxation was evaluated in all consecutive OCT patients between 2005 and 2007. RESULTS: The study population comprised 48 patients 97 ± 77 months after OCT. Thirty-two patients (67%) had an E/A ratio > 2. LV systolic function and myocardial relaxation assessed by the Ea velocity were similar compared to patients with normal ratio (61 ± 6% vs. 60 ± 12%, P = 0.854 and 15 ± 4 cm/s vs. 14 ± 3 cm/s, r = 0.15, P = 0.323, respectively). On the other hand, the proportion of the recipient and donor LA cuffs as estimated by the recipient/global LA area ratio and the LA emptying fraction significantly correlated with the E/A ratio (r = 0.40, P = 0.005 and r =-0.33, P = 0.022, respectively). CONCLUSION: Our study shows that there is a high prevalence of elevated E/A ratio after standard OCT which seems mainly related to reduced LA contractility. Recognition of this "pseudorestrictive" pattern may avoid misdiagnosis of diastolic dysfunction.

Pattern recognition ecological niche models fit to presence-only and presence-absence data

1. Identifying the boundary of a species' niche from observational and environmental data is a common problem in ecology and conservation biology and a variety of techniques have been developed or applied to model niches and predict distributions. Here, we examine the performance of some pattern-recognition methods as ecological niche models (ENMs). Particularly, one-class pattern recognition is a flexible and seldom used methodology for modelling ecological niches and distributions from presence-only data. The development of one-class methods that perform comparably to two-class methods (for presence/absence data) would remove modelling decisions about sampling pseudo-absences or background data points when absence points are unavailable. 2. We studied nine methods for one-class classification and seven methods for two-class classification (five common to both), all primarily used in pattern recognition and therefore not common in species distribution and ecological niche modelling, across a set of 106 mountain plant species for which presence-absence data was available. We assessed accuracy using standard metrics and compared trade-offs in omission and commission errors between classification groups as well as effects of prevalence and spatial autocorrelation on accuracy. 3. One-class models fit to presence-only data were comparable to two-class models fit to presence-absence data when performance was evaluated with a measure weighting omission and commission errors equally. One-class models were superior for reducing omission errors (i.e. yielding higher sensitivity), and two-classes models were superior for reducing commission errors (i.e. yielding higher specificity). For these methods, spatial autocorrelation was only influential when prevalence was low. 4. These results differ from previous efforts to evaluate alternative modelling approaches to build ENM and are particularly noteworthy because data are from exhaustively sampled populations minimizing false absence records. Accurate, transferable models of species' ecological niches and distributions are needed to advance ecological research and are crucial for effective environmental planning and conservation; the pattern-recognition approaches studied here show good potential for future modelling studies. This study also provides an introduction to promising methods for ecological modelling inherited from the pattern-recognition discipline.

Cannabis and tobacco use: where are the boundaries? A qualitative study on cannabis consumption modes among adolescents.

The purpose of this article is to identify tobacco and cannabis co-consumptions and consumers' perceptions of each substance. A qualitative research including 22 youths (14 males) aged 15-21 years in seven individual interviews and five focus groups. Discussions were recorded, transcribed verbatim and transferred to Atlas.ti software for narrative analysis. The main consumption mode is cannabis cigarettes which always mix cannabis and tobacco. Participants perceive cannabis much more positively than tobacco, which is considered unnatural, harmful and addictive. Future consumption forecasts thus more often exclude tobacco smoking than cannabis consumption. A substitution phenomenon often takes place between both substances. Given the co-consumption of tobacco and cannabis, in helping youths quit or decrease their consumptions, both substances should be taken into account in a global approach. Cannabis consumers should be made aware of their tobacco use while consuming cannabis and the risk of inducing nicotine addiction through cannabis use, despite the perceived disconnect between the two substances. Prevention programs should correct made-up ideas about cannabis consumption and convey a clear message about its harmful consequences. Our findings support the growing evidence which suggests that nicotine dependence and cigarette smoking may be induced by cannabis consumption.

Cyclooxygenase-2 controls energy homeostasis in mice by de novo recruitment of brown adipocytes.

Obesity results from chronic energy surplus and excess lipid storage in white adipose tissue (WAT). In contrast, brown adipose tissue (BAT) efficiently burns lipids through adaptive thermogenesis. Studying mouse models, we show that cyclooxygenase (COX)-2, a rate-limiting enzyme in prostaglandin (PG) synthesis, is a downstream effector of beta-adrenergic signaling in WAT and is required for the induction of BAT in WAT depots. PG shifted the differentiation of defined mesenchymal progenitors toward a brown adipocyte phenotype. Overexpression of COX-2 in WAT induced de novo BAT recruitment in WAT, increased systemic energy expenditure, and protected mice against high-fat diet-induced obesity. Thus, COX-2 appears integral to de novo BAT recruitment, which suggests that the PG pathway regulates systemic energy homeostasis.

Dynamics of domain walls in pattern formation under traveling-wave forcing

We study dynamics of domain walls in pattern forming systems that are externally forced by a moving space-periodic modulation close to 2:1 spatial resonance. The motion of the forcing induces nongradient dynamics, while the wave number mismatch breaks explicitly the chiral symmetry of the domain walls. The combination of both effects yields an imperfect nonequilibrium Ising-Bloch bifurcation, where all kinks (including the Ising-like one) drift. Kink velocities and interactions are studied within the generic amplitude equation. For nonzero mismatch, a transition to traveling bound kink-antikink pairs and chaotic wave trains occurs.

External fluctuations in a pattern-forming instability

The effect of external fluctuations on the formation of spatial patterns is analyzed by means of a stochastic Swift-Hohenberg model with multiplicative space-correlated noise. Numerical simulations in two dimensions show a shift of the bifurcation point controlled by the intensity of the multiplicative noise. This shift takes place in the ordering direction (i.e., produces patterns), but its magnitude decreases with that of the noise correlation length. Analytical arguments are presented to explain these facts.

Pattern and clinical significance of cancer-testis gene expression in head and neck squamous cell carcinoma

Les cancer-testis antigènes appartiennent à la famille des antigènes tumoraux spécifiques. Ils ont montré un pouvoir immunogène chez les patients porteurs de différents cancers. En effet, ils stimulent sélectivement les lymphocytes cytotoxiques, et leur expression spécifique dans les tissus tumoraux en fait une cible idéale pour une vaccination antitumorale. Le but de cette étude est d'identifier l'expression de certains de ces antigènes, d'analyser leur valeur pronostique et de déterminer la meilleure cible antigénique pour permettre une immunothérapie spécifique dans les carcinomes épidermoïdes des voies aérodigestives supérieures. Le profil et le taux d'expression de 12 cancer-testis antigènes (MAGE-A1, MAGE-A3, MAGE-A4, MAGEA10, MAGE-C2, NY-ESO-1, LAGE-1, SSX-2, SSX-4, BAGE, GAGE-1/2, GAGE-3/4) et de 3 autres antigènes tumoraux spécifiques (PRAME, HERV-K-MEL, NA-17A) ont été évalués par RT-PCR sur 57 échantillons de cancers ORL primaires. Les paramètres tumoraux et cliniques ont été prospectivement collectés afin de corréler ces données avec le résultat de nos investigations immunobiologiques. Quatre-vingt-huit pour cent des tumeurs expriment au moins 1 antigène. Une co-expression de 3 gènes ou plus est détectée chez 59% des patients. MAGE-A4 (60%), MAGE-A3 (51%), PRAME (49%) et HERV-K-MEL (42%) sont les gènes le plus fréquemment exprimés. Ils sont totalement absents des muqueuses saines avoisinantes. La présence de MAGE-A et NY-ESO-1 à la surface des cellules a été vérifiée par immunohistochimie. Nos analyses statistiques ont permis d'identifier une diminution de la survie liée au cancer chez les patients porteurs d'une tumeur exprimant de multiples cancer-testis antigènes et notamment MAGE-A4 dont l'expression indépendante d'autres éléments cliniques s'associe statistiquement à un taux de survie diminué. Nos résultats ont permis d'identifier un rôle pronostique de l'expression des gènes associés aux tumeurs dont l'expression est apparemment liée à un phénotype de malignité plus élevé. Cette constatation, corroborée par l'identification parallèle d'un infiltrat lymphocytaire spécifique confirme l'utilité potentielle de certains cancer-testis antigènes comme cible pour une immunothérapie ciblée dans les carcinomes des voies aérodigestives supérieures