Obesity, Metabolic Syndrome, and Adipocytes

Obesity and metabolic syndromes are examples whereby excess energy consumption and energy flux disruptions are causative agents of increased fatness. Because other, as yet elucidated, cellular factors may be involved and because potential treatments of these metabolic problems involve systemic agents that are not adipose depot-specific in their actions, should we be thinking of adipose depot-specific (cellular) treatments for these problems? For sure, whether treating obesity or metabolic syndrome, the characteristics of all adipose depot-specific adipocytes and stromal vascular cells should be considered. The focus of this paper is to begin to align metabolic dysfunctions with specific characteristics of adipocytes

In Vitro Methane Production from Heifers Offered Four Bermudagrass Cultivars

Though bermudagrass (Cynodon dactylon [L.] Pers.) is one of the predominant warm-season perennial forage supporting the southeastern United States livestock production systems, little is known about its influence on parameters of ruminal metabolism, including carbon loss as methane. With the multitude of cultivars of this grass that have been developed and released, one may question whether the physiological cultivar differences will manifest varying results in digestive efficiency and subsequent methane emissions. Thus, the objective of this study was to evaluate in vitro methane (CH4) production as influenced by four bermudagrass cultivars. Ruminally-fistulated heifers (n = 4) were assigned randomly to one of four bermudagrass cultivars (Coastal [COS], Russell [RUS], Tifton 44 [T44], or Tifton 85 [T85]) for four 30-d in vivo periods in a Latin square design. On d 28 of each period, rumen fluid was collected from each heifer for use in CH4 production evaluation. Samples of each bermudagrass, corresponding to the cultivar fed, were weighed into duplicate 10-mL serum bottles and incubated at 39°C for 0, 2, 4, and 24 h. Following incubation, headspace samples were assayed for CH4 concentrations by gas chromatography. There was an interaction of cultivar and time (P \u3c 0.01). There was no difference among cultivars (P \u3c 0.05) at 0, 2, or 4 h of incubation. After 24 h of incubation, however, CH4 concentrations were greater (P \u3c 0.05) from T44 and T85 (7.7 and 6.2 mmol/L, respectively) than from RUS and COS (3.4 and 3.0 mmol/L, respectively). Results are interpreted to mean that cultivar type has an influence on the potential CH4 production of bermudagrass

Role of Network Topology in the Synchronization of Power Systems

We study synchronization dynamics in networks of coupled oscillators with bimodal distribution of natural frequencies. This setup can be interpreted as a simple model of frequency synchronization dynamics among generators and loads working in a power network. We derive the minimum coupling strength required to ensure global frequency synchronization. This threshold value can be efficiently found by solving a binary optimization problem, even for large networks. In order to validate our procedure, we compare its results with numerical simulations on a realistic network describing the European interconnected high-voltage electricity system, finding a very good agreement. Our synchronization threshold can be used to test the stability of frequency synchronization to link removals. As the threshold value changes only in very few cases when aplied to the European realistic network, we conclude that network is resilient in this regard. Since the threshold calculation depends on the local connectivity, it can also be used to identify critical network partitions acting as synchronization bottlenecks. In our stability experiments we observe that when a link removal triggers a change in the critical partition, its limits tend to converge to national borders. This phenomenon, which can have important consequences to synchronization dynamics in case of cascading failure, signals the influence of the uncomplete topological integration of national power grids at the European scale.Comment: The final publication is available at http://www.epj.org (see http://www.springerlink.com/content/l22k574x25u6q61m/

'H, I, J, K, L, M, N, O, PEE! Get it? Pee!': Siblings' shared humour in childhood

Humour is a central feature of social interactions in childhood that has received little attention. In a sample of 86 7‐year‐old children (M age = 7.82 years, SD = 0.80), we investigated patterns and individual differences in spontaneous humour observed during free play with their older (M age = 9.55 years, SD = 0.88) or their younger sibling (M age = 5.87 years, SD = 0.96). We coded children's instances, categories, and responses to humour. We investigated the nature of children's humour on the dyadic and individual level. Humour was common, and siblings’ production of humour was highly interdependent between play partners. Dyadic humour differed according to structural features of the sibling relationship (age, gender composition), and 7‐year‐old focal children's humour varied according to gender. This study contributes to knowledge regarding the dyadic nature of children's humour and individual patterns of humour beyond the preschool years

Review: Animal model and the current understanding of molecule dynamics of adipogenesis

Among several potential animal models that can be used for adipogenic studies, Wagyu cattle is the one that presents unique molecular mechanisms underlying the deposit of substantial amounts of intramuscular fat. As such, this review is focused on current knowledge of such mechanisms related to adipose tissue deposition using Wagyu cattle as model. So abundant is the lipid accumulation in the skeletal muscles of these animals that in many cases, the muscle cross-sectional area appears more white (adipose tissue) than red (muscle fibers). This enhanced marbling accumulation is morphologically similar to that seen in numerous skeletal muscle dysfunctions, disease states and myopathies; this might indicate cross-similar mechanisms between such dysfunctions and fat deposition in Wagyu breed. Animal models can be used not only for a better understanding of fat deposition in livestock, but also as models to an increased comprehension on molecular mechanisms behind human conditions. This revision underlies some of the complex molecular processes of fat deposition in animals

Highly site-specific H2 adsorption on vicinal Si(001) surfaces

Experimental and theoretical results for the dissociative adsorption of H_2 on vicinal Si(001) surfaces are presented. Using optical second-harmonic generation, sticking probabilities at the step sites are found to exceed those on the terraces by up to six orders of magnitude. Density functional theory calculations indicate the presence of direct adsorption pathways for monohydride formation but with a dramatically lowered barrier for step adsorption due to an efficient rehybridization of dangling orbitals.Comment: 5 pages, 4 figures, submitted to Phys. Rev. Lett. (1998). Other related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Being in front is good—but where is in front? Preferences for spatial referencing affect evaluation

Speakers of English frequently associate location in space with valence, as in moving up and down the “social ladder.” If such an association also holds for the sagittal axis, an object “in front of” another object would be evaluated more positively than the one “behind.” Yet how people conceptualize relative locations depends on which frame of reference (FoR) they adopt—and hence on cross‐linguistically diverging preferences. What is conceptualized as “in front” in one variant of the relative FoR (e.g., translation) is “behind” under another variant (reflection), and vice versa. Do such diverging conceptualizations of an object's location also lead to diverging evaluations? In two studies employing an implicit association test, we demonstrate, first, that speakers of German, Chinese, and Japanese indeed evaluate the object “in front of” another object more positively than the one “behind.” Second, and crucially, the reversal of which object is conceptualized as “in front” involves a corresponding reversal of valence, suggesting an impact of linguistically imparted FoR preferences on evaluative processes.publishedVersio