The Effect of Competitive Swimming on Oral Health Status

Objectives/Aims: Competitive athletes are often considered to be susceptible to bodily injury. It is now being realized that competitive swimmers are also at risk, specifically in the unsuspected realm of the oral cavity. The purpose of our research is to examine the effect of competitive swimming on an athlete\u27s oral health status. Methods: Using sources found on Pubmed and Google Scholar, the data used for the correlation of swimming pools and generalized dental trauma are as follows: competitive swimmers and non- competitive swimmers were examined for specific variables such as decayed, missing, or restoratively involved teeth, plaque and gingival index, and the presence of enamel erosion, calculus, and stain. The groups evaluated were divided in terms of activity level involving chlorinated swimming pools. Results: Three specific oral health effects will be explored throughout our research. The first oral health effect that will be analyzed is the incidence of chlorine induced calculus buildup exhibited in competitive swimmers. Another health effect that will be examined is the process of dental staining that swimmers can experience when in consistent contact with the pool. Lastly, we will explore erosion of enamel that can occur from the lower pH values of pool water. Through various studies, it has been determined that professional swimmers are likely to exhibit a higher prevalence of generalized erosion of dental enamel, generalized dental stain, and chlorine-induced calculus as opposed to individuals who don’t often swim within chlorinated water. This topic is of great importance as the chemical used to disinfect swimming pools causes evident physical and chemical dental trauma in not only professional swimmers, but also individuals who spend more than 6 hours per week in the pool performing vigorous physical exercise. Conclusion: Oral health in competitive swimmers is a topic that affects many children and adults worldwide, indicating a large prevalence of dental trauma without obvious correlation to the swimming pool despite its significance.https://scholarscompass.vcu.edu/denh_student/1017/thumbnail.jp

Distance and Reddening of the Enigmatic Gamma-ray-Detected Nova V1324 Sco

It has recently been discovered that some, if not all, classical novae emit GeV gamma-rays during outburst. Despite using an unreliable method to determine its distance, previous work showed that nova V1324 Sco was the most gamma-ray luminous of all gamma-ray-detected novae. We present here a different, more robust, method to determine the reddening and distance to V1324 Sco using high-resolution optical spectroscopy. Using two independent methods we derived a reddening of E(B-V) = 1.16 +/- 0.12 and a distance rD > 6.5 kpc. This distance is >40% greater than previously estimated, meaning that V1324 Sco has an even higher gamma-ray luminosity than previously calculated. We also use periodic modulations in the brightness, interpreted as the orbital period, in conjunction with pre-outburst photometric limits to show that a main-sequence companion is strongly favored.Comment: Submitted to ApJ. 6 pages, 5 figure

Where Earth and Life Sciences Intersect: Investigations of the Water-Root-Soil Interface

The transition from deep-rooted perennial prairies to annual row crops has profoundly changed our environment. Roots and soils are interdependent: roots extract water and nutrients from the soil while at the same time influencing the hydrology, structure, composition, and biological community of the soil. Through your active participation, we will introduce a set of inquiry-based lessons developed by a collaboration of ecologists, teachers, and naturalists to engage K-12 students in learning about earth and life sciences in the root zone

Calcium entry into stereocilia drives adaptation of the mechanoelectrical transducer current of mammalian cochlear hair cells

Mechanotransduction in the auditory and vestibular systems depends on mechanosensitive ion channels in the stereociliary bundles that project from the apical surface of the sensory hair cells. In lower vertebrates, when the mechanoelectrical transducer (MET) channels are opened by movement of the bundle in the excitatory direction, Ca2+ entry through the open MET channels causes adaptation, rapidly reducing their open probability and resetting their operating range. It remains uncertain whether such Ca2+-dependent adaptation is also present in mammalian hair cells. Hair bundles of both outer and inner hair cells from mice were deflected by using sinewave or step mechanical stimuli applied using a piezo-driven fluid jet. We found that when cochlear hair cells were depolarized near the Ca2+ reversal potential or their hair bundles were exposed to the in vivo endolymphatic Ca2+ concentration (40 µM), all manifestations of adaptation, including the rapid decline of the MET current and the reduction of the available resting MET current, were abolished. MET channel adaptation was also reduced or removed when the intracellular Ca2+ buffer 1,2-Bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA) was increased from a concentration of 0.1 to 10 mM. The findings show that MET current adaptation in mouse auditory hair cells is modulated similarly by extracellular Ca2+, intracellular Ca2+ buffering, and membrane potential, by their common effect on intracellular free Ca2+. Hearing and balance depend on the transduction of mechanical stimuli into electrical signals. This process depends on the opening of mechanoelectrical transducer (MET) channels located at the tips of the shorter of pairs of adjacent stereocilia (1), which are specialized microvilli-like structures that form the hair bundles that project from the upper surface of hair cells (2,3). Deflection of hair bundles in the excitatory direction (i.e., toward the taller stereocilia) stretches specialized linkages, the tip-links, present between adjacent stereocilia (3⇓–5), opening the MET channels. In hair cells from lower vertebrates, open MET channels reclose during constant stimuli via an initial fast adaptation mechanism followed by a much slower, myosin-based motor process, both of which are driven by Ca2+ entry through the channel itself (6⇓⇓⇓⇓⇓⇓–13). In mammalian auditory hair cells, MET current adaptation seems to be mainly driven by the fast mechanism (14⇓–16), although the exact process by which it occurs is still largely unknown. The submillisecond speed associated with the adaptation kinetics of the MET channels in rat and mouse cochlear hair cells (17, 18) indicates that Ca2+, to cause adaptation, has to interact directly with a binding site on the channel or via an accessory protein (16). However, a recent investigation on rat auditory hair cells has challenged the view that Ca2+ entry is required for fast adaptation, and instead proposed an as-yet-undefined mechanism involving a Ca2+-independent reduction in the viscoelastic force of elements in series with the MET channels (19). In the present study, we further investigated the role of Ca2+ in MET channel adaptation in mouse cochlear hair cells by deflecting their hair bundles using a piezo-driven fluid jet, which is believed to produce a more uniform deflection of the hair bundles (20⇓⇓–23) compared with the piezo-driven glass rod (19, 24)

Influence of weaning age (28 vs. 63 d) on quantitative and qualitative carcass traits of rabbits

Nowadays there is an increasing interest towards breeding systems, also for rabbit meat production, that are more mindful of animal welfare through an attenuation of the productive cycles intensity. These particular rearing techniques provide a delaying of the weaning age to reduce young rabbits stress. The present experiment is part of a wider research (Pinna et al., 2004; Marongiu et al., 2004) conducted in a sardinian farm in which rabbits are usually weaned at about 60 days of age. Surely this managerial choice could be considered rather questionable but from a scientific point of view could also represent the occasion to examine the productive performance of rabbits submitted to such a late weaning. The final part of the survey, regarding the carcass composition and the meat chemical-nutritional characteristics, was carried out through the comparison of two groups of rabbits weaned at 28 and at 63 days of age respectively

The assessment of selenium bioaccessibility and bioavailability from selenium-rich algae

Selenium (Se) is an essential trace mineral known for its role as an antioxidant in oxidation-reduction reactions. Due to deficiency in many parts of the world, development of new Se supplementation is increasing in popularity. The objective of this study was to examine the bioaccessiblity (BAC) and bioavailability (BA) from Se-rich algae using an in vitro digestion/Caco-2 cell model. Algal samples were grown in Se-rich media with varying concentrations of either selenite or selenate, then subjected to in vitro digestion. The centrifuged supernatent was applied on the Caco-2 cell monolayer for a 24-h treatment. BAC was tested based on the Se solubility post in vitro digestion and BA by induction of cellular glutathione peroxidase activity (GPx1) in a Se deficient Caco-2 cell model. Algal samples were compared to Se-salts, selenomethionine (SeMet) and Se-yeast commonly used in supplementation. Cells treated with algae grown in selenate had a mean GPx1 activity that was 15-62% (p\u3c0.05) of the GPx1 activity relative to the cells with SeMet treatment. Cells treated with algae grown in selenite had a mean GPx1 activity that was 11-34% (p\u3c0.05) of the GPx1 activity from SeMet treated cells. Additionally, the Se-yeast treated cells had 134% (p\u3c0.05) GPx1 activity, selenate salt treated cells had 214% (p\u3c0.05) GPx1 activity, and selenite salt treated cells had 126% (p\u3c0.05) GPx1 activity of the SeMet treated cells. The results indicated that the Se-rich algae was not as effective as traditional Se supplementation in increasing GPx1 activity. However, the results provided valuable information to improve future Se BA of algae

Peripheral Arterial Disease Screening of an Underserved High Risk Population

Disparity in access to health care and preventive services places a heavier burden of morbidity on those with limited access and resources. Underserved populations with decreased access to appropriate health screening and therapeutic interventions often present with increased risks for peripheral arterial disease. Some patients with peripheral arterial disease are asymptomatic and may defer treatment while others present with occlusive disease requiring immediate therapy. Delaying diagnosis and treatment reduces quality of life and functional status. The prevalence of peripheral arterial disease has been extensively studied in the elderly population but the prevalence in the high-risk underserved population is unknown. The purpose of this study was to identify the prevalence of peripheral arterial disease in an underserved, high-risk, predominantly African American population and to determine if providers using an electronic blood pressure machine could accurately measure the ankle-brachial index. The sample population of forty adult residents at a homeless shelter in northeast Florida was screened for peripheral arterial disease. Inclusion criteria consisted of a diagnosis of hypertension, hyperlipidemia, diabetes or a history of smoking. The ankle-brachial index was assessed using the vascular Doppler method and an electronic blood pressure machine though the latter was found to be an insensitive screening tool. The ankle-brachial index, the San Diego Claudication Questionnaire and a physical assessment were used in this crosssectional study to determine the prevalence of peripheral arterial disease. An abnormal ankle-brachial index value (≤ 0.90), indicating a high suspicion of peripheral arterial disease, was assessed in 22.5% of the sample population, all of whom were found to have a history of smoking crack cocaine

Tmc1 point mutation affects Ca2+ sensitivity and block by dihydrostreptomycin of the mechanoelectrical transducer current of mouse outer hair cells

The transduction of sound into electrical signals depends on mechanically sensitive ion channels in the stereociliary bundle. The molecular composition of this mechanoelectrical transducer (MET) channel is not yet known. Transmembrane channel-like protein isoforms 1 (TMC1) and 2 (TMC2) have been proposed to form part of the MET channel, although their exact roles are still unclear. Using Beethoven (Tmc1Bth/Bth) mice, which have an M412K point mutation in TMC1 that adds a positive charge, we found that Ca2+ permeability and conductance of the MET channel of outer hair cells (OHCs) were reduced. Tmc1Bth/Bth OHCs were also less sensitive to block by the permeant MET channel blocker dihydrostreptomycin, whether applied extracellularly or intracellularly. These findings suggest that the amino acid that is mutated in Bth is situated at or near the negatively charged binding site for dihydrostreptomycin within the permeation pore of the channel. We also found that the Ca2+ dependence of the operating range of the MET channel was altered by the M412K mutation. Depolarization did not increase the resting open probability of the MET current of Tmc1Bth/Bth OHCs, whereas raising the intracellular concentration of the Ca2+ chelator BAPTA caused smaller increases in resting open probability in Bth mutant OHCs than in wild-type control cells. We propose that these observations can be explained by the reduced Ca2+ permeability of the mutated MET channel indirectly causing the Ca2+ sensor for adaptation, at or near the intracellular face of the MET channel, to become more sensitive to Ca2+ influx as a compensatory mechanism