Functional evolution of the feeding system in rodents

The masticatory musculature of rodents has evolved to enable both gnawing at the incisors and chewing at the molars. In particular, the masseter muscle is highly specialised, having extended anteriorly to originate from the rostrum. All living rodents have achieved this masseteric expansion in one of three ways, known as the sciuromorph, hystricomorph and myomorph conditions. Here, we used finite element analysis (FEA) to investigate the biomechanical implications of these three morphologies, in a squirrel, guinea pig and rat. In particular, we wished to determine whether each of the three morphologies is better adapted for either gnawing or chewing. Results show that squirrels are more efficient at muscle-bite force transmission during incisor gnawing than guinea pigs, and that guinea pigs are more efficient at molar chewing than squirrels. This matches the known diet of nuts and seeds that squirrels gnaw, and of grasses that guinea pigs grind down with their molars. Surprisingly, results also indicate that rats are more efficient as well as more versatile feeders than both the squirrel and guinea pig. There seems to be no compromise in biting efficiency to accommodate the wider range of foodstuffs and the more general feeding behaviour adopted by rats. Our results show that the morphology of the skull and masticatory muscles have allowed squirrels to specialise as gnawers and guinea pigs as chewers, but that rats are high-performance generalists, which helps explain their overwhelming success as a group

Optimization Conditions for froth Separation black Coal Slurries

Import 05/08/2014Diplomová práce je zpracovaná na téma „Optimalizace podmínek pěnové separace černouhelných kalů“. Na začátku mé práce je popsána pěnová separace, její princip, kinetika procesu a reagenční činidla. Dále je uvedena charakteristika černouhelných kalů. Následuje stanovení optimálních podmínek na výnos a kvalitu produktů rozdružování. Poté je uvedeno vyhodnocení dosažených výsledků. V závěru práce jsou shrnuty poznatky a výsledky diplomové práce. Poté je zařazen seznam použité literatury a zdrojů.Diploma thesis elaborated on the theme of “Processing optimalization Conditions for froth Separation black Coal Slurries“. At the beginning of my work is circumscribed froth Separation, the principles, itself course of the process and floatation surfactants. Next part is characterization black coal slurries. Followed by an evaluation of optimum conditions on the yield and quality of product separation. After specified evaluation of results. Following is a list of the included literature, resources and index attachmentsPrezenční542 - Institut hornického inženýrství a bezpečnostivýborn

Correlation between maximum in-shoe plantar pressures and clubhead speed in amateur golfers

Disagreements exist in the literature regarding the manner in which weight should be dynamically shared during the golf swing, both within-feet and between the back- and target-foot, to generate maximal clubhead speed. The purpose of this study was to determine whether preferential foot-loading locations underlie weight sharing by examining the correlation between clubhead speed and maximum plantar pressure (PP) distributions. Thirty-two amateur golfers with handicap indexes ranging from 2.7 to 25 performed 10 driver swings on artificial turf following a warm-up. PP distributions were recorded at 100 Hz, and clubhead speed was recorded using a ball-tracking Doppler radar system. Maximum PPs were extracted from a 2-s window approximately centred on ball contact and were regressed against clubhead speed. Significance was assessed over the entire foot surface using statistical parametric mapping (SPM), a spatially continuous technique. SPM revealed, at relatively high anatomical resolution, significant positive correlations between clubhead speed and PPs in the lateral target-foot (P < 0.05). This suggests that not only weight transfer but also weight-transfer location may be an important determinant of clubhead speed in amateur golfers.ArticleJOURNAL OF SPORTS SCIENCES. 33(2):192-197 (2015)journal articl

"Ne dotikajte se!". Danasnje vizualne kompetence otrok v primerjavi s preddigitalno dobo v luci njihovega likovnovzgojnega okolja

The task of twenty-first century art education is to contribute to the blossoming of the child’s personality. In this article, I approach this challenge from two principal directions, both of which provide a window onto unfamiliar terrain. This project sought to answer the following research questions: How do plastic, spatial (3D) creative capacities develop, and how do they compare with the kindergarten’s accustomed advancement of picture-creating, planar (2D) capabilities? How do kindergartners’ skills as measured in the 1970s compare with those of kindergartners today? A follow-on project examined children’s skills in the context of built environment education, asking the questions: Where, and with whom, do children find the best conditions for creation and arts education? What kinds of environments are most favourable? The results showed a clear deterioration of children’s drawing development from 1974 until today, as well as from drawings in both studies to modelling today. However, a more promising discovery was that depictions of movement appear much sooner in the case of plastic arts works than in drawings. This opens the way to an orientation that in our increasingly urbanised world, can help our children grow into adults who responsibly shape our environment, sensitive to their own age, as self-possessed problem solvers, employing the toolkit of education through art. The study is based on ongoing, long-term research of the 3612+ Visual Skills Lab group, employing both qualitative and quantitative methods to evaluate the artistic proficiencies of nearly a thousand children, mostly aged 3–7, in dozens of kindergartens in Hungary, through hands-on exercises as well as surveys of teachers, parents and other interested parties. (DIPF/Orig.

Is economic value added (eva) the best way to assemble a portfolio?

In search of a better investment metric, researchers began to study Economic Value Added, or EVA, which was introduced in 1991 by Stern Stewart & Co in their book, The Quest for Value (Turvey, 2000). Stern Stewart & Co devised EVA as a better alternative to evaluate investment projects within the corporate finance field, later to be considered for use as a performance metric for investor use. A wide array of multinational corporations, such as Coca-Cola, Briggs and Stratton, and AT&T adopted the EVA method, which led to EVA\u27s worldwide acclaim. Several points in the study reveal that EVA does not offer less risk, higher returns, and more adaptability for an investor. In fact, EVA underperformed the traditional portfolio performance metrics in key measurements including mean returns, and confidence intervals. EVA is a difficult performance metric to calculate, with several complex components that can be calculated in several different ways such as NOPAT, cost of equity, and cost of debt. Any information that is inaccurate or lacking can significantly impact the outcomes. Traditional performance metrics, on the other hand, such as ROA, ROE, and E/P are simple to calculate with few components, and only one way to calculate them

The influence of the CYP1A2 polymorphism on the effect of caffeine ingestion and mouth rinsing on 3km cycling performance

PURPOSE: The objectives were to determine the effects of caffeine ingestion and mouth rinsing on cycling performance, and to assess whether the CYP1A2 gene is related to the size of the performance effects. METHODS: Thirty-eight recreational cyclists completed four simulated 3-kilometer time trials (TT). Subjects ingested either 6mg/kgBW of caffeine or placebo one hour prior to each TT. Additionally, 25 ml of 1.14% caffeine, or placebo solution was mouth rinsed before each TT. Treatments were: placebo ingestion+placebo rinse (Placebo), placebo ingestion+caffeine rinse (Rinse), caffeine ingestion+caffeine rinse (Ingestion+Rinse), caffeine ingestion+placebo rinse (Ingestion). Subjects were genotyped and classified as AA homozygotes or C allele carriers for the rs762551 polymorphism in CYP1A2. Magnitude based inferences were used to evaluate treatment differences. RESULTS: Both Ingestion+Rinse (‘likely’) and Ingestion (‘possibly’) improved performance compared to Placebo. Performance differences between Ingestion+Rinse and Ingestion and between Rinse and Placebo were ‘likely trivial.’ C allele carriers experienced greater gains (‘likely’) with Ingestion compared to AA homozygotes. Additional analyses revealed that caffeine intake conferred larger benefits for subjects that performed trials prior to 10am. CONCLUSIONS: Caffeine ingestion, but not mouth rinse, improved cycling performance. C allele carriers experienced the largest improvement in performance with caffeine ingestion, especially prior to 10am