Evaluating modularity in the hominine skull related to feeding biomechanics.

OBJECTIVES: Modular architecture of traits in complex organisms can be important for morphological evolution at micro- and sometimes macroevolutionary scales as it may influence the tempo and direction of changes to groups of traits that are essential for particular functions, including food acquisition and processing. We tested several distinct hypotheses about craniofacial modularity in the hominine skull in relation to feeding biomechanics. MATERIALS AND METHODS: First, we formulated hypothesized functional modules for craniofacial traits reflecting specific demands of feeding biomechanics (e.g., masseter leverage/gape or tooth crown mechanics) in Homo sapiens, Pan troglodytes, and Gorilla gorilla. Then, the pattern and strength of modular signal was quantified by the covariance ratio coefficient and compared across groups using covariance ratio effect size. Hierarchical clustering analysis was then conducted to examine whether a priori-defined functional modules correspond to empirically recovered clusters. RESULTS: There was statistical support for most a priori-defined functional modules in the cranium and half of the functional modules in the mandible. Modularity signal was similar in the cranium and mandible, and across the three taxa. Despite a similar strength of modularity, the empirically recovered clusters do not map perfectly onto our priori functional modules, indicating that further work is needed to refine our hypothesized functional modules. CONCLUSION: The results suggest that modular structure of traits in association with feeding biomechanics were mostly shared with humans and the two African apes. Thus, conserved patterns of functional modularity may have facilitated evolutionary changes to the skull during human evolution.

In-air experimental achievement of high-voltage DC power supply to be installed in a tandem electrostatic accelerator system for boron neutron capture therapy application.

The boron neutron capture therapy (BNCT) system developed by the Korea Institute of Radiological and Medical Sciences is a compact neutron source that can be installed at medical institutes. The target energy was accelerated to a maximum of 2.4 MeV-20 mA by introducing a gas stripping device that converts negative hydrogen ions into positive ions. By using the tandem-type accelerator in this way, a high-voltage DC power supply was designed with 1.2 MV-45 mA as the maximum capability. The design was improved to reduce the number of stages of a Cockcroft-Walton voltage multiplier. Hence, the ripple risk of the DC flat top resulting from unwanted stray capacitance was lowered. The overall height and volume of the Cockcroft-Walton voltage multiplier were reduced to less than half those of the existing design method, making miniaturization possible. After such advanced design and manufacturing, performance tests were performed at 750 kV-45 mA under 23 stages of the Cockcroft-Walton voltage multiplier, which is the highest level that can perform at its maximum under in-air conditions. It demonstrated stable performance under in-air conditions without breakdown for 2 h, even at 620 kV-35 mA. To reach the final target of 1.2 MV-45 mA, the groundwork is laid for achieving experimental performance while satisfying the optimal requirements in SF6 gas.

Functional morphological integration related to feeding biomechanics in the hominine skull.

Quantifying and characterizing the pattern of trait covariances is crucial for understanding how population-level patterns of integration might constrain or facilitate craniofacial evolution related to the feeding system. This study addresses an important gap in our knowledge by investigating magnitudes and patterns of morphological integration of biomechanically informative traits in the skulls of Homo sapiens, Pan troglodytes, and Gorilla gorilla. We predicted a lower magnitude of integration among human biomechanical traits since humans eat a softer, less biomechanically challenging diet than apes. Indeed, compared to African apes, the magnitudes of integration were lower in H. sapiens skulls for form data (raw dimensions) but were similar or higher for shape data (raw dimensions scaled by geometric mean). Patterns of morphological integration were generally similar, but not identical, across the three species, particularly for the form data compared to the shape data. Traits that load heavily on the primary axis of variation in morphospace are generally associated with size and/or shape of the temporalis and masseter muscles and with dimensions related to the constrained lever model of jaw biomechanics. Given the conserved nature of morphological integration, skull adaptations for food processing in African apes and humans may have been constrained to occur along certain paths of high evolvability. The conserved pattern of functional integration also indicates that extant hominine species can operate as reasonable analogues for extinct hominins in studies that require population-level patterns of trait variance/covariance.

COVID-19 and Unmet Medical Needs for People With Chronic Diseases: A Cross-Sectional Study.

Gaps between medical needs and health services accessibility are defined as unmet medical needs (UMN). Previous studies assessing UMNs during the coronavirus disease 2019 (COVID-19) pandemic did not account for factors such as the type of medical insurance or chronic disease. Therefore, this study investigated various factors, including medical insurance and chronic diseases, affecting self-reported UMN during the pandemic in Daejeon Metropolitan City, South Korea. This cross-sectional study was conducted using Daejeon Metropolitan City Health Surveys data from 2020. The weighted prevalence of UMN was estimated among participants (n = 1494) aged ≥18 years, while chi-squared and logistic models were used to assess the association between UMN and participant characteristics. The prevalence of UMN was 6.4% (n = 97). Female sex and low education levels were significantly associated with reporting UMN. Medical aid beneficiaries were less likely to report UMN than adults with National Health Programs coverage. Participants with chronic diseases, such as hypertension and arthritis, and those with depression, were more likely to report UMN than adults without these conditions. The findings highlight the need for targeted efforts to decrease UMN in the COVID-19 pandemic, especially for women and individuals with low education levels. The results also indicate that high-risk disease groups should be targeted with additional enabling services to support the management of chronic conditions.

Morphological modularity in the anthropoid axial skeleton.

Previous research has found that hominoids have stronger modularity between limb elements than other anthropoids, suggesting that there is less constraint on morphological diversification (e.g., limb proportions) in hominoids in terms of evolutionary independence. However, degrees of modularity in the axial skeleton have not been investigated across a broad range of anthropoid taxa. Thus, it is unknown whether hominoids also have stronger modularity in the axial skeleton than other anthropoids, which has implications for the evolution of diverse torso morphologies in Miocene apes as well as the evolution of novel characteristics in the skull and vertebrae of fossil hominins. In this study, 12 anthropoid genera were sampled to examine degrees of modularity between axial skeletal elements (i.e., cranium, mandible, vertebrae, and sacrum). Covariance ratio coefficients were calculated using variance/covariance matrices of interlandmark distances for each axial skeletal element to evaluate degrees of modularity. The results showed that Alouatta, Hylobates, Gorilla, Pan, and Homo showed generally stronger modularity than other anthropoid taxa when considering all axial skeletal elements. When only considering the vertebral elements (i.e., vertebrae and sacrum), Alouatta, Hylobates, Gorilla, and Pan showed generally stronger modularity than other anthropoid taxa. Humans showed stronger modularity between the skull and vertebrae than other hominoids. Thus, the evolution of novel characteristics in the skull and vertebral column may have been less constrained in fossil hominins due to the dissociation of trait covariation between axial skeletal elements in hominoid ancestors, thus fostering more evolutionary independence between the skull and vertebral column.

Effect of computerized cognitive rehabilitation in comparison between young and old age after traumatic brain injury.

INTRODUCTION: Cognitive dysfunction reduces patients' quality of life and social participation with traumatic brain injury (TBI). Computerized cognitive rehabilitation is increasingly being used for cognitive therapy in TBI patients. The purpose of this study was to investigate the influence of age on the effect of computerized cognitive rehabilitation in cognitive dysfunction after TBI. MATERIAL AND METHODS: A total of 34 patients with cognitive dysfunction after TBI were enrolled. Participants performed 30 sessions of computerized cognitive rehabilitation (Comcog) for 6 weeks. A cognitive evaluation was performed before and after treatment with Mini-Mental State Examination (MMSE) and Computerized Neurophyschologic Test (CNT). RESULTS: There were no cognitive tests that differed between the young group and the old group at baseline. However, after computerized cognitive rehabilitation, the young group showed significant improvement compared to the old group in verbal memory, visual memory, attention, and visuo-motor coordination tests. The young group showed improvement in MMSE, verbal and visual memory, and visuo-motor coordination tests after computerized cognitive rehabilitation. In contrast, the old group showed significant improvement only in MMSE and visual learning test, one of the visual memory tests. CONCLUSION: Our findings demonstrate that age may be an important factor related to the effect of computer cognitive rehabilitation on cognitive dysfunction after TBI. Methodologically more ordered studies with larger sample sizes are needed in the future.

Analysis of the physiological load on lumbar vertebrae in patients with osteoporosis: a finite-element study.

This study aims to investigate the difference in physiological loading on the spine in three different motions (flexion-extension, lateral bending, and axial rotation) between osteoporotic and normal spines, using finite element modelling. A three-dimensional finite element (FE) model centered on the lumbar spine was constructed. We applied two different material properties of osteoporotic and normal spines. For the FE analysis, three loading conditions (flexion-extension, lateral bending, and axial rotation) were applied. The von Mises stress was higher on the nucleus pulposus at all vertebral levels in all movements, in the osteoporosis group than in the normal group. On the annulus fibrosus, the von Mises stress increased at the level of L3-L4, L4-L5, and L5-S in the flexion-extension group and at L4-L5 and L5-S levels in the lateral bending group. The values of two motions, flexion-extension and lateral bending, increased in the L4 and L5 cortical bones. In axial rotation, the von Mises stress increased at the level of L5 of cortical bone. Additionally, the von Mises stress increased in the lower endplate of L5-S and L4-L5 in all movements, especially lateral bending. Even in the group with no increase, there was a part that received increased von Mises stress locally for each element in the three-dimensional reconstructed view of the pressure distribution in color. The von Mises stress on the lumbar region in the three loading conditions, was greater in most components of osteoporotic vertebrae than in normal vertebrae and the value was highest in the nucleus pulposus. Considering the increase in the measured von Mises stress and the local increase in the pressure distribution, we believe that these results can contribute to explaining discogenic pain and degeneration.

Machine Learning Strategies for Low-Cost Insole-Based Prediction of Center of Gravity during Gait in Healthy Males.

Whole-body center of gravity (CG) movements in relation to the center of pressure (COP) offer insights into the balance control strategies of the human body. Existing CG measurement methods using expensive measurement equipment fixed in a laboratory environment are not intended for continuous monitoring. The development of wireless sensing technology makes it possible to expand the measurement in daily life. The insole system is a wearable device that can evaluate human balance ability by measuring pressure distribution on the ground. In this study, a novel protocol (data preparation and model training) for estimating the 3-axis CG trajectory from vertical plantar pressures was proposed and its performance was evaluated. Input and target data were obtained through gait experiments conducted on 15 adult and 15 elderly males using a self-made insole prototype and optical motion capture system. One gait cycle was divided into four semantic phases. Features specified for each phase were extracted and the CG trajectory was predicted using a bi-directional long short-term memory (Bi-LSTM) network. The performance of the proposed CG prediction model was evaluated by a comparative study with four prediction models having no gait phase segmentation. The CG trajectory calculated with the optoelectronic system was used as a golden standard. The relative root mean square error of the proposed model on the 3-axis of anterior/posterior, medial/lateral, and proximal/distal showed the best prediction performance, with 2.12%, 12.97%, and 12.47%. Biomechanical analysis of two healthy male groups was conducted. A statistically significant difference between CG trajectories of the two groups was shown in the proposed model. Large CG sway of the medial/lateral axis trajectory and CG fall of the proximal/distal axis trajectory is shown in the old group. The protocol proposed in this study is a basic step to have gait analysis in daily life. It is expected to be utilized as a key element for clinical applications.

Is Conservative Treatment Better than Surgical Treatment for Basal Ganglia Hemorrhage in a Conventionally Non-Surgical Indication Group with Poor Motor Function?

Background: The treatment options for basal ganglia intracerebral hemorrhage (ICH), either surgical or conservative, remain controversial. A previous study developed "A new modified ICH (MICH) score" that suggests which treatment option will be better for basal ganglia ICH. According to this scoring system, a MICH score of 0 or 1 indicates that conservative treatment is better than surgical treatment. The purpose of this study was to determine whether conservative treatment is still a better option for a basal ganglia hemorrhage in patients with MICH scores of 0 and 1, with initial poor motor grades. Methods: This retrospective study was comprised of 41 patients with a spontaneous basal ganglia hemorrhage. These patient groups had no previous brain lesions, their initial MICH score was 0 or 1, and the manual muscle test (MMT) of their hand was grade 2+ or lower in the initial evaluation. All patients were transferred to the Department of Rehabilitation Medicine and received rehabilitation treatment. Ten patients had an operative intervention, which was burr-hole aspiration or craniotomy with hematoma removal. The control group included 31 patients who underwent conservative treatment. Outcome evaluations used the Berg Balance Scale (BBS), Modified Barthel Index (MBI), and Brunnstrom recovery stage (BRS) which were evaluated at initial and regular follow-ups after 1, 3, and 6 months. We defined an improvement state if the BRS of their hand became 4 or more in 6 months, which means an escape from the synergic pattern. Results: Demographic characteristics showed no significant differences in age, sex, hemiplegic side, initial GCS score, presence of IVH and hydrocephalus, or distribution of MICH scores 0 and 1. There was only a significant difference in the distribution of hematoma volume between groups of less than 20 mL and groups from 21 to 50 mL (p = 0.049). There were no significant differences in MBI values in 1 month or improvement of BRS of their hand in 6 months between the two groups. Conclusions: Even in the group classified as predominantly conservative in basal ganglia hemorrhage patients, if the initial muscle strength is low, it is necessary to reconsider whether conservative treatment is superior to surgical treatment in terms of functional improvement.

Financial burden of catastrophic health expenditure on households with chronic diseases: financial ratio analysis.

BACKGROUND: The financial status of households is vulnerable to chronic diseases which entail high medical expenses and income loss. Financial strain can be assessed by four indicators: a household surplus indicator, the liquid asset/debt ratio, a solvency indicator, and a liquidity indicator. We investigated the association between catastrophic health expenditure (CHE) and financial ratio indicators in households with chronic diseases in South Korea. METHODS: This study applied thresholds to the financial ratios to determine the financial strain. We conducted multiple logistic regression analyses to determine whether CHE is associated with financial strain. Furthermore, we analyzed the relationship between CHE and basic financial indicators, absolute finance size, using multiple linear regression. RESULTS: When CHE occurred, all financial ratio indicators deteriorated. However, this was not due to decreases in the absolute size of wealth and income, but rather the relative balance between finances. In particular, the loss of liquid assets was a major factor in the deterioration. In addition, all types of labor-related income deteriorated; only private transfer income increased. CONCLUSIONS: This study revealed that CHE in households with chronic diseases negatively impacts household finances. It was found that financial coping strategies are only resource consuming.

What Policy Approaches Were Effective in Reducing Catastrophic Health Expenditure? A Systematic Review of Studies from Multiple Countries.

BACKGROUND: The United Nations set a goal for universal health coverage in all countries by 2030 and selected the catastrophic health expenditure (CHE) indicator as an assessment tool for this goal. Many countries have strived to reduce household CHE. However, no study has compared countries whose policies have had a remarkable effect on decreasing CHE. Therefore, the purpose of this systematic literature review is to find appropriate methods for measuring CHE that can help us to analyze the impact of health policies and identify countries whose health policies are most effective in reducing CHE. METHOD: PubMed and Web of Science were searched. Studies that measured the incidence or intensity of CHE in multiple years were included. Two independent reviewers screened the literature, extracted the data, and analyzed the studies selected. Thirty-eight studies met the inclusion criteria for the review. We classified the selected research papers to random sampling and quasi-experimental studies. RESULTS: We graphically presented the results of CHE incidence and intensity rates reported in the collected papers as a time series data set. Since most studies did not use sample weights, it was not easy to confirm whether the time series changes of CHE are significant. Therefore, we could find only two countries that had policy effects. Both countries established policies that focus on the poor. CONCLUSION: There are so many studies that analyze CHE, but policies that are effective in reducing CHE are unknown. This study uses a systematic literature review methodology to determine effective policies by comparing CHE time series trends among countries. As a policy implication, it was found that because CHE is defined as the ratio of the ability to pay to medical expenses, a policy of differential medical expenses that is based on income level is effective.

Optimal design of high-voltage DC power supply of 1.2 MV/45 mA applied to boron neutron capture therapy system.

To build a proton beam accelerator that can be applied to a boron neutron capture therapy system based on an electrostatic accelerator, a high-voltage direct-current (DC) power supply system equivalent to the generation of neutrons should be provided. The symmetrical Cockcroft-Walton voltage multiplier method is suitable for stable acceleration of the proton beam in the tandem electrostatic accelerator in this system. Before the second step-up with the Cockcroft-Walton circuit, the design of the inverter is prioritized by preponderantly considering the first voltage and resonance frequency. Moreover, the optimized stacking number is determined with consideration of the ripple voltage, voltage drop, average output voltage, and fundamental harmonics, and a design is performed to set related parameter values to be stable in the flat-top region of the voltage. A high-voltage DC power supply system of 1.2 MV/45 mA is needed for a stable terminal energy of 2.4 MeV/20 mA. Such a design can be optimized by securing reliable data using a simulation tool on the basis of theoretical calculations. This will become a formidable touchstone in manufacturing technology based on acquiring practical know-how for setting up a tandem electrostatic accelerator-based boron neutron capture therapy system in the future.

The Effectiveness of Computer-Assisted Cognitive Rehabilitation and the Degree of Recovery in Patients with Traumatic Brain Injury and Stroke.

Objectives: To determine the effectiveness of computer-assisted cognitive rehabilitation and compare the patterns of cognitive function recovery occurring in both traumatic brain injury (TBI) and stroke. Methods: A total of 62 patients were finally enrolled, consisting of 30 with TBI and 32 with stroke. The patients received 30 sessions of computer-assisted cognitive rehabilitation (Comcog) five times per week. Each session lasted for 30 min. Before and immediately after cognitive rehabilitation, all patients were evaluated by computerized neuropsychological test (CNT), Mini-Mental State Examination (MMSE), and modified Barthel index (MBI). Results: We analyzed the differences between pre- and post-cognitive rehabilitation in each TBI and stroke group. Significant differences were observed in MMSE, MBI, and some CNT contents, including digit span forward, verbal learning, verbal learning delayed recall, visual span forward, visual span backward, visual learning, trail making test A and B, and intelligence quotient (IQ) in the TBI group (p < 0.05). In the stroke group, in addition to significant differences that appeared in the TBI group, additional significant differences in the digit span backward, visual learning delayed recall, auditory continuous performance test (CPT), visual CPT, and card sorting test. We compared the difference values at pre- and post-cognitive rehabilitation for cognitive recovery between the TBI and stroke groups. All contents, except the digital span forward, visual learning, word-color test, and MMSE, had greater mean values in the stroke group; and thus, statistically significant higher values were observed in the visual span forward and card sorting test (p < 0.05). Conclusion: Most evaluation results showed improvement and the evaluation between the TBI and stroke groups also showed significant differences in cognitive functions in addition to more CNT contents, which significantly change in the stroke group. The stroke group showed a high difference value in most CNT contents. Therefore, those with stroke in the focal brain region tend to have better cognitive function recovery after a computer-assisted cognitive rehabilitation than those with TBI, which could cause diffuse brain damage and post-injury inflammation.

Estimating the effectiveness of national health insurance in covering catastrophic health expenditure: Evidence from South Korea.

The catastrophic health expenditure (CHE) indicator has been used to measure the medical cost burden of households. Many countries have institutionalized their health insurance systems to reduce out-of-pocket payments, the main contributor to the financial burden. However, there is no method to estimate how the insurance coverage reduces the CHE. This study proposes an approach to evaluate the effectiveness of insurance in reducing the CHE impacts in terms of incidence and gap, which are based on a modified calculation method of CHE. Additionally, we apply these methods to data from the Korea Health Panel Survey (2011-2016). The results are as follows. First, under the setting of a threshold of 10%, the CHE incidence rate was 19.26% when the Korean national health insurance benefits reduced the CHE's incidence for 15.17% of the population in 2017. Second, the results of the concentration index of CHE showed that the intensity approach of CHE is better than the incidence approach. Third, the new approach we applied revealed that health insurance reduces the burden of CHE to some degree, although it was not an efficient way to reduce CHE. In conclusion, this study provides new policy approaches to save the finances of national health insurance and reduce the intensity of CHE at the same time by raising the low-cost burden of medical services and lowering that of high cost. Moreover, we suggest that policymakers should focus on income level of the households rather than specific diseases.

The Effect of Mid-to-Long-Term Hospitalization on the Catastrophic Health Expenditure: Focusing on the Mediating Effect of Earned Income Loss.

BACKGROUND: Mid-to-long-term hospitalization (MLTH) can threaten the household economy with high medical costs and loss of income. Therefore, it could increase the catastrophic health expenditure (CHE), measured as the ratio of medical expenses to the ability to pay. This study aimed to determine the effect of MLTH on the incidence of CHE and the mediating effect of earned income reduction rate (EIRR). METHODS: We used 2015 to 2017 data from the Korean Welfare Panel Study and selected households with earned income through work. The final samples were 1671 households in the database. This study applied three-step regression analyses for estimating mediation effects. RESULTS: First, MLTH affected CHE increases; second, MLTH increased EIRR; third, both EIRR and MLTH increased CHE at the same time. Additionally, the bootstrapping results were 0.364 to 0.644 in the 95% confidence interval, which suggested that EIRR mediated the effects of MLTH on CHE. CONCLUSIONS: Previous studies have only focused on medical costs when interpreting CHE; however, it is also essential to recognize that the MLTH can have a negative effect on the EIRR. This study contributed to the literature by giving another insight into interpreting the cause of CHE, focusing on income loss factors.

Experimental Demonstration of 3 × 3 MIMO LED-to-LED Communication Using RGB Colors.

Optical wireless communication (OWC) is one of the promising candidates for beyond fifth-generation communication (B5G). Depending on the type of transmitters, receivers, and information carriers applied in the system, OWC can be categorized into visible light communication, light fidelity, free-space optical communication, optical camera communication, etc. In addition to these OWC subcategories, this paper proposes light-emitting diode (LED)-to-LED communication as another subcategory of OWC technique. Furthermore, we show an experimental demonstration of the multiple-input multiple-output (MIMO) LED-to-LED communication system using red, green, and blue colored LEDs. We believe that LED-to-LED communication is an effective solution to resolve the communication burden arising from massive connectivity in B5G internet of things. Along with the measurement results of the transmitter LED, receiver LED, and the channel properties, it is shown that the MIMO LED-to-LED system is able to successfully recover the transmitted signal with low inter-channel interferences due to the receiver LED's unique characteristics. Finally, the bit error rate (BER) performance of the MIMO LED-to-LED system is shown in comparison with the BER performance of the single-input single-output (SISO) LED-to-LED system. We successfully implemented the 3 × 3 MIMO LED-to-LED communication system using RGB colors at a data rate of 30.62 kbps over a 10 cm transmission distance along with direct current biased optical orthogonal frequency division multiplexing (DCO-OFDM) modulation and zero-forcing (ZF) equalizer.

Examination of magnitudes of integration in the catarrhine vertebral column.

The evolution of novel vertebral morphologies observed in humans and other extant hominoids may be related to changes in the magnitudes and/or patterns of covariation among traits. To examine this, we tested magnitudes of integration in the vertebral column of cercopithecoids and hominoids, including humans. Three-dimensional surface scans of 14 vertebral elements from 30 Cercopithecus, 32 Chlorocebus, 39 Macaca, 45 Hylobates, 31 Pan, and 86 Homo specimens were used. A resampling method was used to generate distributions of integration coefficient of variation scores for vertebral elements individually using interlandmark distances. Interspecific comparisons of mean integration coefficient of variation were conducted using Mann-Whitney U tests with Bonferroni adjustment. The results showed that hominoids generally had lower mean integration coefficient of variation than cercopithecoids. In addition, humans showed lower mean integration coefficient of variation than other hominoids in their last thoracic and lumbar vertebrae. Cercopithecoids and Hylobates showed relatively lower mean integration coefficient of variation in cervical vertebrae than in thoracolumbar vertebrae. Pan and Homo showed relatively lower mean integration coefficient of variation in the last thoracic and lumbar vertebrae in the thoracolumbar region, except for the L1 of Pan. The results suggest fewer integration-mediated constraints on the evolution of vertebral morphology in hominoids when compared with cercopithecoids. The weaker magnitudes of integration in lumbar vertebrae in humans when compared with chimpanzees likewise suggest fewer constraints on the evolution of novel lumbar vertebrae morphology in humans.

Submandibular Push Exercise Using Visual Feedback from a Pressure Sensor in Patients with Swallowing Difficulties: A Pilot Study.

Objectives: We aimed to determine the usefulness and effectiveness of a submandibular push exercise with visual feedback from a pressure sensor in patients with dysphagia through continuous exercise sessions. Methods: Twelve patients with dysphagia of various etiologies were included. A total of five exercise sessions (every 3 or 4 days) over three weeks were conducted. During the submandibular push exercise, patients were instructed to maintain a maximum force for 3 s, repeated for 1 min to measure the number of exercises, the maximum pressure, and the area of the pressure-time graph. We statistically compared the values of each exercise trial. Results: Among the 12 patients, eight completed the exercise sessions. As the number of exercise trials increased, the maximum pressure and the area in the pressure-time graph showed a significant increase compared to the previous attempt (p < 0.05). The maximum pressure and the area of the pressure-time graph improved from the first to the fourth session (p < 0.05). The values were maintained after the fourth session, and there was no significant difference between the fourth and the fifth exercise (p > 0.05). There was no significant difference between successful and non-successful groups, except for the Modified Barthel Index (p < 0.05). Conclusion: Through repetitive exercise training, the submandibular push exercise using visual feedback from a pressure sensor can be applied as an exercise method to strengthen swallowing related muscles, such as the suprahyoid and infrahyoid muscles. However, additional studies including more patients and a long-term study period are warranted to evaluate the effects of the exercise for improvement of dysphagia.

Ontogenetic changes in magnitudes of integration in the macaque skull.

OBJECTIVES: Magnitudes of morphological integration may constrain or facilitate craniofacial shape variation. The aim of this study was to analyze how the magnitude of integration in the skull of Macaca fascicularis changes throughout ontogeny in relation to developmental and/or functional modules. MATERIALS AND METHODS: Geometric morphometric methods were used to analyze the magnitude of integration in the macaque cranium and mandible in 80 juvenile and 40 adult M. fascicularis specimens. Integration scores in skull modules were calculated using integration coefficient of variation (ICV) of eigenvalues based on a resampling procedure. Resultant ICV scores between the skull as a whole, and developmental and/or functional modules were compared using Mann-Whitney U tests. RESULTS: Results showed that most skull modules were more tightly integrated than the skull as a whole, with the exception of the chondrocranium in juveniles without canines, the chondrocranium/face complex and the mandibular corpus in adults, and the mandibular ramus in all juveniles. The chondrocranium/face and face/mandibular corpus complexes were more tightly integrated in juveniles than adults, possibly reflecting the influences of early brain growth/development, and the changing functional demands of infant suckling and later masticatory loading. This is also supported by the much higher integration of the mandibular ramus in adults compared with juveniles. DISCUSSION: Magnitudes of integration in skull modules reflect developmental/functional mechanisms in M. fascicularis. However, the relationship between "evolutionary flexibility" and developmental/functional mechanisms was not direct or simple, likely because of the complex morphology, multifunctionality, and various ossification origins of the skull.