A pilot study of nocturnal temporalis muscle activity in TMD diagnostic groups of women.

Temporomandibular disorder (TMD) incidences are believed to be related to parafunctional behaviours like teeth clenching. This pilot study aimed to (i) develop an automated clench-detection algorithm, and (ii) apply the algorithm to test for differences in nocturnal clenching in women with and without TMD. Subjects gave informed consent to participate. Adult women were categorised using Diagnostic Criteria for TMD according to presence/absence (+/-) of both TM joint disc placement (DD) and chronic pain (P) into two groups (+DD+P, -DD-P) with 12 subjects each. Surface temporalis electromyography was recorded during oral tasks performed by subjects at two laboratory sessions. The data were used to characterise muscle activity per N of bite force (µV/N) for each subject, develop the clench-detection algorithm and test its accuracy. Ambulatory surface temporalis electromyography was self-recorded by each subject over three nights and analysed using the algorithm and bite force (N) versus muscle activity µV/N calibrations. Bonferroni-adjusted homoscedastic t-tests assessed for significant between-group differences in clenching (P < 0·05). Sensitivity, specificity and accuracy of algorithm-detected laboratory clenches were all ≥96%. During self-recordings 95% of clenches had durations of <4 s and peak forces of <10 N in both groups. Mean clench durations were significantly longer (P = 0·042) in +DD+P (1·9 ± 0·8 s) than -DD-P subjects (1·4 ± 0·4 s). Mean temporalis duty factors (%clench time/total recording time) were significantly larger (P = 0·041) in +DD+P (0·47 ± 0·34%) than -DD-P (0·26 ±0·22%) subjects. Nocturnal temporalis muscle activities detected by a validated algorithm were longer per clench and recording time in +DD+P compared to -DD-P women.

Suction among pickers: jaw mechanics, dietary breadth and feeding behaviour in beach-spawning Leuresthes spp. compared with their relatives.

Jaw mechanics and dietary breadth in California grunion Leuresthes tenuis and Gulf grunion Leuresthes sardina were compared with three other members of the tribe Atherinopsini to test whether these two species have evolved a novel jaw protrusion that might be associated with feeding narrowly on abundant prey near spawning beaches. Quantitative comparison of cleared-and-stained specimens of five members of the atherinopsine clade showed that, compared with false grunion Colpichthys regis, topsmelt Atherinops affinis and jacksmelt Atherinopsis californiensis, L. tenuis and L. sardina have longer, more downwardly directed premaxillary protrusion, expanded dentary and premaxillary bones, greater lower jaw rotation and larger premaxilla-vomer separation. Leuresthes tenuis showed greater differences than L. sardina in these features. Comparison of the gut contents of L. tenuis and A. affinis with zooplankton samples collected simultaneously with these fishes in the water column within 1 km of shore showed that, as predicted, L. tenuis fed predominantly on mysid crustaceans and had a narrower diet than A. affinis. High-speed video analysis showed that L. tenuis exhibits a mean time to maximum jaw protrusion c. 2.5 times shorter than that of A. affinis. The grunion sister species, especially L. tenuis, have evolved suction feeding that may allow efficient feeding on common, evasive prey near spawning sites. The morphological traits seen in both species of Leuresthes signify a marked difference from their closest relatives in prey capture and suggest a type of jaw protrusion not yet seen in cyprinodontiforms or perciforms.

Evolution of ontogenetic dietary shifts and associated gut features in prickleback fishes (Teleostei: Stichaeidae).

We tested the hypothesis that an ontogenetic dietary shift from carnivory to herbivory or omnivory, and concomitant changes in the gut facilitating digestion of algae, are synapomorphies of the tribes Xiphisterini and Esselenichthyini in the family Stichaeidae (pricklebacks). Previous investigations have revealed that two xiphisterine pricklebacks-Xiphister mucosus and Xiphister atropurpureus-become herbivorous or omnivorous, respectively, as their bodies grow larger, and that their guts show related changes in length and function. In this study we found that, with increase in size, the basal member of the Xiphisterini, Phytichthys chirus, showed an increased proportion of algae in its diet, increased activity of α-amylase and decreased activity of aminopeptidase, all of which support the synapomorphy hypothesis. Cebidichthys violaceus, a herbivore in the Esselenichthyini, shows similar ontogenetic changes in diet and digestive tract length and physiology, but these features were not observed in two derived carnivores, Dictyosoma burgeri and Dictyosoma rubrimaculatum, within the clade. These results suggest that herbivory is isolated to C. violaceus within the Esselenichthyini. Allometric relationships of gut length as a function of body size generally follow diet within the Xiphisterini and Esselenichthyini, with herbivores having the longest guts, which become disproportionately longer than body size as the fishes grow, omnivores intermediate gut lengths, and carnivores the shortest. A carnivore from an adjacent clade, Anoplarchus purpurescens, had the shortest gut, which did not change in length relative to body length as the fish grew. Overall, our results clarify the patterns of dietary evolution within the Stichaeidae and lay the foundation for more detailed studies of dietary and digestive specialization in fishes in the family.

Current trends in ventilation of the pediatric patient.

This article presents an overview of the varied modes of ventilation and supportive adjuncts for the pediatric patient. Ventilatory management has changed over the past few decades with the advent of high-frequency ventilation, pressure control-inverse ratio, pressure-regulated volume control, volume support, noninvasive bi-level pressure ventilation such as BiPAP, and the emergence of adjuncts to improve oxygenation such as surfactant, extracorporeal membrane oxygenation, nitric oxide, and total and partial liquid ventilation. Ventilatory management of pediatric patients mandates an armamentarium including guided imagery and the use of speech enhancers. A multidisciplinary team approach is essential.

Artificial airways: a survey of cuff management practices.

OBJECTIVE: To determine current endotracheal and tracheostomy tube cuff management practices in adult and pediatric populations, and to compare current adult cuff management practice with those reported in use in 1984 and 1987. DESIGN: Descriptive survey. SETTING: Sixty-four acute care hospitals in the northeastern United States. SAMPLE: Responders represented 93 critical care units: 59 adult and 34 pediatric units. MEASUREMENTS: Subjects completed a survey questionnaire. RESULTS: Forty-one percent reported cuffs were routinely deflated, with most (88%) reporting cuff deflation every 8 to 12 hours or daily. In the pediatric population, minimal occlusive volume was the most frequent technique (29%); whereas in the adult population, both minimal occlusive volume technique and minimal leak technique were used more frequently (36%). Most (93%) cuff pressures were measured every 8 to 12 hours or daily with a recommended maximum range of 20 to 30 mm Hg. Cuff deflation and cuff inflation were performed more often by the nursing staff (36%). Cuff pressures were performed more often by respiratory staff (71%). There were no statistically significant differences in the cuff management practices between the adult and pediatric populations. In comparing the results for adults to the data of 1984 and 1987, most cuff management practices changed from every 8 hours or less to every 8 to 12 hours or daily, and the nursing responsibility for these techniques increased (22%). CONCLUSION: Most responders do not routinely deflate cuffs. Cuff management practices are performed less frequently, and nursing responsibility for these techniques has increased.

Medical applications of copolyester elastomer films.

Medical dressings and devices are now required to fulfil a number of demands. These include preventing the entry of bacteria to the wound and improving the healing rate. Copolyester elastomers (COPEs) can play a significant role in providing these benefits because they can be blended to offer a range of characteristics. In this article, the author discusses the mechanical and physical properties of COPEs and discusses how these properties have been utilized, and their potential for future development.

Ultrastructure and biochemistry of the pineal organ in deep-sea lanternfishes (Myctophidae).

Pineal structural and biochemical adaptations in lanternfishes included: 1) few photoreceptor outer segment discs; 2) conventional synapses between photoreceptors and pineal neurons; and 3) low levels (0-60 pg/pineal) of serotonin compared to those (greater than 1.0 ng/pineal) in the goldfish pineal organ. These findings suggest reduced photosensory and/or neuroendocrine functions in these deep-sea fishes.

Acanthonus armatus, a deep-sea teleost fish with a minute brain and large ears.

Acanthonus armatus, a deep-water benthopelagic fish, has, per unit body weight, the smallest brain and largest semicircular canals of any known teleost and possibly any vertebrate. Pertinent areas of the brainstem and the cerebellum are large; this observation suggests that the fish's lateral line and vestibular senses are particularly acute. The huge cranial cavity also contains heavy saccular otoliths, which may indicate that the fish is sensitive to low-frequency sound. Brain size and specialization are consistent with an apparent pattern of low energy requirement, hovering and slow movement over the deep-sea floor, and consumption of small benthic prey in a dark environment.

Optimal diets in complex environments: feeding strategies of two herbivorous fishes from a temperate rocky intertidal zone.

The seasonal diets of Cebidichthys violaceus and Xiphister mucosus, two herbivorous fishes from the complex, multifood environment of the central California rocky intertidal zone, were partially consistent with three predictions of optimal diet models based on energy maximization: 1) The prediction that at high food densities a forager should concentrate solely on the energetically most valuable items was incompletely met by these two fish species. C. violaceus and X. mucosus increased their consumption of energy-rich annual macrophytes during periods (summer and fall) of high food abundance, but nevertheless continued to take a mixed diet. 2) The prediction that abundance of lower-valued foods does not determine their inclusion in the diet was largely upheld by the feeding habits of these two intertidal fishes. The probability of an item being consumed apparently depends upon its abundance as well as its chemical composition. 3) The prediction that foragers will generalize as food abundance declines was largely met by the two fishes since their diets broadened considerably during periods (e.g. winter) of reduced food supply. Furthermore, diets of the two species converged during periods of high food abundance and diverged during months of low food abundance. Whether this seasonal pattern of overlap was due to interspecific competition or other factors is unknown. This study, in agreement with other recent investigations, indicates that optimal diet models cannot be based solely on energy maximization but should also include nutrient constraints in order to more accurately predict the seasonally fluctuating mixed diets of these fishes and other generalist herbivores.

Petroleum lumps on the surface of the sea.

Lumps of crude oil residue floating the sea surface have been observed widely. Samples were taken with surface-skimming nets in the Mediter-ranean Sea and eastern North Atlantic Ocean; their displacement volumes were as large as 0.5 milliliter per square meter. An isopod, Idotea metallica, appears to be associated with the lumps, and a barnacle, Lepas pectinata, grows upon them. Lumps were found in stomachs of Scomberesox saurus, a surface-feeding fish importanit in ocean food webs. Films on the lumps, presumably consisting mostly of bacteria, consumed oxygen at the rate of 4 cubic millimeters per hour per square centimeter of lump surface. Chemical analysis suggested that certain lumps had been at large for only a few weeks; data from barnacle size and growth rate suggested that other lumps were at least 2 months old.