scholarly journals The role of hyoid muscles in biotremor production in Chamaeleo calyptratus

2020 ◽  
Vol 223 (22) ◽  
pp. jeb227603
Author(s):  
Samuel M. Tegge ◽  
Christopher V. Anderson ◽  
Michael E. Smith ◽  
Steve Huskey

ABSTRACTThe production of biotremors has been described in veiled chameleons (Chamaeleo calyptratus), but the mechanism by which they are produced is unknown. We gathered muscle activation data via electromyography (EMG), with simultaneous recordings of biotremors using an accelerometer, to test for the role of hyoid muscles in biotremor production. We recorded a mean biotremor frequency of 150.87 Hz for females and 136.01 Hz for males. The durations of activity and the latencies to onset and offset for the M. sternohyoideus profundus (SP), M. sternohyoideus superficialis (SS), Mm. mandibulohyoideus (MH) and M. levator scapulae (LS) were all significantly correlated with biotremor durations and biotremor onset and offset, respectively. Linear mixed-effect regression model comparisons of biotremor duration indicated that models containing either the MH and/or the SP and LS account for the most variation in biotremor duration. Twitch times for the SP (100 ms) and the SS (132 ms) at field active body temperature, however, were individually too slow to produce the biotremors at the observed frequency without alteration after production by other anatomical structures. These results implicate the SP, SS, MH and LS in the production of biotremors, but the exact mechanism of production requires further study.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254370
Author(s):  
Philipp Schindler ◽  
Luca Mautone ◽  
Eileen Bigdon ◽  
Vasyl Druchkiv ◽  
Martin Stefan Spitzer ◽  
...  

Purpose Lens opacification is a common complication after pars plana vitrectomy (PPV) and knowing its progression would facilitate consulting patients. The purpose of this study was to evaluate a quantitative model for lens-status-monitoring after PPV with C3F8 gas. Our model was evaluated in rhegmatogenous retinal detachment (RRD) patients of various age and lens densitometry (LD). Methods Data between March 2018 and March 2020 were evaluated retrospectively. LD measurements of the PentacamHR® Nucleus Staging mode (PNS) were used to quantify lens opacification over time. A mixed-effect regression model was designed, to enable LD predictions at any time postoperatively. Calculations were based on patient’s age and baseline LD as dependent variables. Six patients were randomly excluded during model development, to be used for testing its power afterwards. Results 34 patients (male 19 [55.9%], female 15 [44.1%]) matched the inclusion criteria. Average age was 58.5 years (32–77;±4.3) and average follow-up was 7.2 months (3,4–23.1;±1,8). Mean baseline LD of the treated and fellow eye before surgery were 10.9% (8.7%-14.8%;±0.8) and 10.7% (8.5%-14.1%;±0.6), respectively. Using our prediction model, LD values for the six pre-selected patients closely match the observed data with an average deviation of 1.07%. Conclusions Evaluation of age and baseline LD using a mixed-effect regression model might predict cataract progression in RRD patients treated with PPV and C3F8-gas. Such a tool could be considered during cataract surgery consultation in these patients.


1998 ◽  
Vol 17 (20) ◽  
pp. 2313-2333 ◽  
Author(s):  
Pascal Girard ◽  
Terrence F. Blaschke ◽  
Helen Kastrissios ◽  
Lewis B. Sheiner

2013 ◽  
Vol 84 (2) ◽  
pp. 286-291 ◽  
Author(s):  
Young Jae Huh ◽  
Kyung-Hoe Huh ◽  
Hong-Kyun Kim ◽  
Shin-Eun Nam ◽  
Hye Yoon Song ◽  
...  

ABSTRACT Objective: To investigate the constancy of the angle between the Frankfort horizontal plane (FH) and the sella-nasion line (SN) using longitudinal data. Materials and Methods: Longitudinal lateral cephalometric data of 223 children (116 girls and 107 boys) from 6 to 14 years of age were used. The angle between FH and SN (SNFH), the distance from FH to the nasion (NFH), the distance from FH to the sella (SFH), and the differences between the NFH and SFH (Δ) were also measured. All data were analyzed statistically using independent t-tests and mixed-effect regression model analysis. Results: The mean SNFH values showed some minor fluctuations, ranging from 9.26° to 9.74° in girls and 8.45° to 8.95° in boys. The mean NFH and SFH values gradually increased according to age irrespective of sex. There were statistically significant differences by sex for all measurements at several ages. The annual change in SFH and Δ showed sexual dimorphism. Conclusions: There are variations among individuals in the angle between the FH and SN. However, within an individual, the angle does not vary significantly over time during the observation period.


2019 ◽  
Vol 35 (3) ◽  
pp. 1351-1365 ◽  
Author(s):  
Miguel A. Jaimes ◽  
Gabriel Candia

This article presents a correlation model for pseudo-acceleration, peak ground acceleration, and peak ground velocity residuals using a database of Mexican subduction interface earthquakes at rock sites (NEHRP Class B). A mixed-effect regression model, a ground motion model, and 40 event recordings (418 records) with moment magnitude between five and eight were used to develop a magnitude-independent correlation model. This region-specific model yields consistently higher correlation values compared with similar studies developed for shallow crustal regions and other subduction zones worldwide, particularly for pseudo-acceleration values at distant periods. These results support the idea of using a region-specific and mechanism-specific correlation model for Mexico's subduction zone.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
E Osawa ◽  
M Ichikawa ◽  
M Ochi ◽  
T Mine ◽  
M Otaga

Abstract Backgrounds In Japan, some parents with an infant have limited network with others and are feeling anxious and less confident about their child rearing. Many measures for promoting a child-rearing family friendly community are implemented to promote families' healthy development in communities. However, a situation surrounding child-rearing in a community is diverse. The aim of this study is to examine possible indices to monitor and evaluate child-rearing family friendly community. Methods This was a cross sectional study with using two kinds of data in one city in Japan. The first one was public data providing information about physical environment related to child-rearing of each community. The second data was on questionnaire answered by a parent of infants from 3 months to 48 months through 2013 to 2019. We merged two kinds of data and examined the association between environment and parents' willingness to raise up children in their community (4 scales) by mixed effect regression model stratified by age of months (under 1 year, 1- and 2-years and 3-years). Results Targets of analysis included 2,952 parents of infant under 1 year, 2,342 of 1- and 2-years and 1,977 of 3-year. For parents of infant of 1- and 2-years and 3-years, the closer a child-rearing support center was, the bigger the willingness to raise up a child in their community (β[95%CI]:-0.007[-0.014-/-0.0004], -0.007[-0.012/-0.002, respectively). Also, for parents of 1- and 2-years infant, the closer the park was, the bigger the willingness (-0.014[-0.028/-0.0008]). On the other hand, for parents of infant under 1 year, environment was not statistically significant on their willingness. Conclusions It was indicated that user's easiness to visit a consulting space or playing place such as a child-rearing support center or a park become one of indicators for evaluating child-rearing family friendly community in Japan. Key messages Child-rearing family friendly environment in a community should be evaluated from the user’s aspect. Further studies including evaluation quality of places or services are needed.


2021 ◽  
Vol 10 (2) ◽  
pp. e001230
Author(s):  
Michael Reid ◽  
George Kephart ◽  
Pantelis Andreou ◽  
Alysia Robinson

BackgroundRisk-adjusted rates of hospital readmission are a common indicator of hospital performance. There are concerns that current risk-adjustment methods do not account for the many factors outside the hospital setting that can affect readmission rates. Not accounting for these external factors could result in hospitals being unfairly penalized when they discharge patients to communities that are less able to support care transitions and disease management. While incorporating adjustments for the myriad of social and economic factors outside of the hospital setting could improve the accuracy of readmission rates as a performance measure, doing so has limited feasibility due to the number of potential variables and the paucity of data to measure them. This paper assesses a practical approach to addressing this problem: using mixed-effect regression models to estimate case-mix adjusted risk of readmission by community of patients’ residence (community risk of readmission) as a complementary performance indicator to hospital readmission rates.MethodsUsing hospital discharge data and mixed-effect regression models with a random intercept for community, we assess if case-mix adjusted community risk of readmission can be useful as a quality indicator for community-based care. Our outcome of interest was an unplanned repeat hospitalisation. Our primary exposure was community of residence.ResultsCommunity of residence is associated with case-mix adjusted risk of unplanned repeat hospitalisation. Community risk of readmission can be estimated and mapped as indicators of the ability of communities to support both care transitions and long-term disease management.ConclusionContextualising readmission rates through a community lens has the potential to help hospitals and policymakers improve discharge planning, reduce penalties to hospitals, and most importantly, provide higher quality care to the people that they serve.


Water exchange between insects and their environment via the vapour phase includes influx and efflux components. The pressure cycle theory postulates that insects (and some other arthropods) can regulate the relative rates of influx and efflux of water vapour by modulating hydrostatic pressures at a vapour-liquid interface by compressing or expanding a sealed, gas-filled cavity. Some such cavities, like the tracheal system, could be compressed by elevated pressure in all or part of the haemocoele. Others, perhaps including the muscular rectum of flea prepupae, could be compressed by intrinsic muscles. Maddrell Insect Physiol . 8, 199 (1971)) suggested a pressure cycle mechanism of this kind to account for rectal uptake of water vapour in Thermobia but did not find it compatible with quantitative information then available. Newer evidence conforms better with the proposed mechanism. Cyclical pressure changes are of widespread occurrence in insects and have sometimes been shown to depend on water status. Evidence is reviewed for the role of the tracheal system as an avenue for net exchange of water between the insect and its environment. Because water and respiratory gases share common pathways, most published findings fail to distinguish between the conventional view that the tracheal system has evolved as a site for distribution and exchange of respiratory gases and that any water exchange occurring in it is generally incidental and nonadaptive, and the theory proposed here. The pressure cycle theory offers a supplementary explanation not incompatible with evidence so far available. The relative importance of water economy and respiratory exchange in the functioning of compressible cavities such as the tracheal system remains to be explored. Some further implications of the pressure cycle theory are discussed. Consideration is given to the possible involvement of vapour-phase transport in the internal redistribution of water within the body. It is suggested that some insect wings may constitute internal vapour-liquid exchange sites, where water can move from the body fluids to the intratracheal gas. Ambient and body temperature must influence rates of vapour-liquid mass transfer. If elevated body temperature promotes evaporative discharge of the metabolic water burden that has been shown to accumulate during flight in some large insects, their minimum threshold thoracic temperature for sustained flight may relate to the maintenance of water balance. The role of water economy in the early evolution of insect wings is considered. Pressure cycles might help to maintain water balance in surface-breathing insects living in fresh and saline waters, but the turbulence of the surface of the open sea might prevent truly marine forms from using this mechanism.


2003 ◽  
Vol 481 (2-3) ◽  
pp. 133-140 ◽  
Author(s):  
Jihua Jiang ◽  
Peter H Backx ◽  
Hwee Teoh ◽  
Michael E Ward

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