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1.
Exp Brain Res ; 242(5): 1115-1126, 2024 May.
Article in English | MEDLINE | ID: mdl-38483567

ABSTRACT

The use of functional near-infrared spectroscopy (fNIRS) for brain imaging during human movement continues to increase. This technology measures brain activity non-invasively using near-infrared light, is highly portable, and robust to motion artifact. However, the spatial resolution of fNIRS is lower than that of other imaging modalities. It is unclear whether fNIRS has sufficient spatial resolution to differentiate nearby areas of the cortex, such as the leg areas of the motor cortex. Therefore, the purpose of this study was to determine fNIRS' ability to discern laterality of lower body contractions. Activity in the primary motor cortex was recorded in forty participants (mean = 23.4 years, SD = 4.5, female = 23, male = 17) while performing unilateral lower body contractions. Contractions were performed at 30% of maximal force against a handheld dynamometer. These contractions included knee extension, knee flexion, dorsiflexion, and plantar flexion of the left and right legs. fNIRS signals were recorded and stored for offline processing and analysis. Channels of fNIRS data were grouped into regions of interest, with five tolerance conditions ranging from strict to lenient. Four of five tolerance conditions resulted in significant differences in cortical activation between hemispheres. During right leg contractions, the left hemisphere was more active than the right hemisphere. Similarly, during left leg contractions, the right hemisphere was more active than the left hemisphere. These results suggest that fNIRS has sufficient spatial resolution to distinguish laterality of lower body contractions. This makes fNIRS an attractive technology in research and clinical applications in which laterality of brain activity is required during lower body activity.


Subject(s)
Functional Laterality , Motor Cortex , Spectroscopy, Near-Infrared , Humans , Spectroscopy, Near-Infrared/methods , Male , Female , Young Adult , Functional Laterality/physiology , Adult , Motor Cortex/physiology , Muscle Contraction/physiology , Brain Mapping/methods
2.
Adv Sci (Weinh) ; 11(10): e2303516, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38155460

ABSTRACT

Impaired cerebrovascular function contributes to the genesis of age-related cognitive decline. In this study, the hypothesis is tested that impairments in neurovascular coupling (NVC) responses and brain network function predict cognitive dysfunction in older adults. Cerebromicrovascular and working memory function of healthy young (n = 21, 33.2±7.0 years) and aged (n = 30, 75.9±6.9 years) participants are assessed. To determine NVC responses and functional connectivity (FC) during a working memory (n-back) paradigm, oxy- and deoxyhemoglobin concentration changes from the frontal cortex using functional near-infrared spectroscopy are recorded. NVC responses are significantly impaired during the 2-back task in aged participants, while the frontal networks are characterized by higher local and global connection strength, and dynamic FC (p < 0.05). Both impaired NVC and increased FC correlate with age-related decline in accuracy during the 2-back task. These findings suggest that task-related brain states in older adults require stronger functional connections to compensate for the attenuated NVC responses associated with working memory load.


Subject(s)
Cognitive Dysfunction , Neurovascular Coupling , Humans , Aged , Neurovascular Coupling/physiology , Brain/physiology , Frontal Lobe
3.
Exp Brain Res ; 241(6): 1555-1567, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37127798

ABSTRACT

Older adults with Type II Diabetes Mellitus (DM) experience mild cognitive impairment, specifically in the domain of recall/working memory. No consistent causative structural cortical deficits have been identified in persons with DM (PwDM). Memory deficits may be exacerbated in older adult females, who are at the highest risk of cardiovascular decline due to DM. The focus of the current study was to evaluate functional cortical hemodynamic activity during memory tasks in postmenopausal PwDM. Functional Near Infrared Spectroscopy (fNIRS) was used to monitor oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) during memory-based tasks in a cross-sectional sample of postmenopausal women with DM. Twenty-one community-dwelling DM females (age = 65 ± 6 years) and twenty-one age- and sex-matched healthy controls (age = 66 ± 6 years) were evaluated. Working memory performance (via N-back) was evaluated while study participants donned cortical fNIRS. Health state, metabolic data, and menopausal status data were also collected. Deficits in working memory accuracy were found in the DM group as compared to controls. Differences in HbO responses emerged in the DM group. The DM group exhibited altered PFC activity magnitudes and increased functional cortical activity across ROIs compared to controls. HbO and HbR responses were not associated with worsened health state measures. These data indicate a shift in cortical activity patterns with memory deficits in postmenopausal PwDM. This DM-specific shift of HbO is a novel finding that is unlikely to be detected by fMRI. This underscores the value of using non-MRI-based neuroimaging techniques to evaluate cortical hemodynamic function to detect early mild cognitive impairment.


Subject(s)
Diabetes Mellitus, Type 2 , Spectroscopy, Near-Infrared , Humans , Female , Aged , Middle Aged , Spectroscopy, Near-Infrared/methods , Postmenopause , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnostic imaging , Cross-Sectional Studies , Memory Disorders/diagnostic imaging , Memory Disorders/etiology , Memory, Short-Term/physiology
4.
Reg Anesth Pain Med ; 47(4): 222-227, 2022 04.
Article in English | MEDLINE | ID: mdl-35058345

ABSTRACT

BACKGROUND: Local anesthetic wound infusion catheters are increasingly used postmidline laparotomy to reduce pain and opioid use, however there is little evidence to support any particular infusion regime. METHODS: A retrospective cohort study was undertaken of patients after midline laparotomy who had bilateral local anesthetic wound infusion catheters surgically placed. Patients were recruited into 3 cohorts: ropivacaine 0.2% 5-8 mL/hour continuous wound infusion, 10 mL programmed intermittent bolus 2 hourly, 20 mL programmed intermittent bolus 4 hourly. The primary outcome was the maximum daily Numerical Rating Pain Score with movement (dynamic pain score) recorded during first 96 hours postprocedure. Secondary outcomes included the maximum daily resting pain score and opioid utilization. RESULTS: In three cohorts of 70 patients (n=210), the maximum daily dynamic pain score in the intermittent bolus 2-hourly and 4-hourly cohorts was lower when compared with the continuous infusion group over the first 4 postoperative days. The mean difference in maximum daily pain score with respect to the continuous infusion regime was 0.8 (95% CI 0.2 to 1.4) for the intermittent bolus 2-hourly group and 0.6 (95% CI 0.0 to 1.2) for the 4-hourly group. Generalized estimating equation modeling indicates the reduction in dynamic pain score is greatest with the intermittent bolus 2-hourly regime over the first 72 hours postprocedure. The 2-hourly intermittent bolus regime was also associated with lower opioid utilization and local anesthetic exposure. CONCLUSIONS: Intermittent wound infusion catheter infusion regimes were associated with lower maximum daily dynamic pain scores, although the magnitude of this change may be of limited clinical significance.


Subject(s)
Analgesia , Anesthetics, Local , Analgesics, Opioid/adverse effects , Anesthetics, Local/adverse effects , Catheters , Humans , Laparotomy/adverse effects , Pain , Pain Management/adverse effects , Pain, Postoperative/diagnosis , Pain, Postoperative/etiology , Pain, Postoperative/prevention & control , Retrospective Studies
5.
Am J Biol Anthropol ; 177(1): 4-26, 2022 01.
Article in English | MEDLINE | ID: mdl-36787710

ABSTRACT

OBJECTIVES: This study aims to examine primate postcanine tooth root surface area (TRSA) in the context of two ecological variables (diet and bite force). We also assess scaling relationships within distinct taxonomic groups and across the order as a whole. MATERIALS AND METHODS: Mandibular postcanine TRSA was measured using a three-dimensional computed tomography (CT) method for catarrhine (N = 27), platyrrhine (N = 21), and strepsirrhine (N = 24) taxa; this represents the first sample of strepsirrhines. Two different body size proxies were used: cranial geometric mean (GM) using nine linear measurements, and literature-derived body mass (BM). RESULTS: TRSA correlated strongly with body size, scaling with positive allometry or isometry across the order as a whole; however, scaling differed significantly between taxa for some teeth. Among Strepsirrhini, molar TRSA relative to GM differed significantly between folivores and pliant-object feeders. Additionally, P4 TRSA relative to BM differentiated folivores from both hard- and pliant-object feeders. Among Cercopithecoidea, P4 TRSA adjusted by GM differed between hard- and pliant-object feeders. DISCUSSION: Dietary signals in TRSA appear primarily driven by high frequency loading experienced by folivores. Stronger and more frequent dietary signals were observed within Strepsirrhini relative to Haplorhini. This may reflect the constraints of orthognathism within the latter, constraining the adaptability of their postcanine teeth. Finally, because of the strong correlation between TRSA and BM for each tooth locus (mean r2  = 0.82), TRSA can be used to predict BM in fossil primates using provided equations.


Subject(s)
Strepsirhini , Tooth , Animals , Primates , Tooth Root/diagnostic imaging , Diet
6.
Sci Rep ; 11(1): 20994, 2021 10 25.
Article in English | MEDLINE | ID: mdl-34697326

ABSTRACT

Sleep deprivation (SD) is a common condition and an important health concern. In addition to metabolic and cardiovascular risks, SD associates with decreases in cognitive performance. Neurovascular coupling (NVC, "functional hyperemia") is a critical homeostatic mechanism, which maintains adequate blood supply to the brain during periods of intensive neuronal activity. To determine whether SD alters NVC responses and cognitive performance, cognitive and hemodynamic NVC assessments were conducted prior to and 24 h post-SD in healthy young male individuals (n = 10, 27 ± 3 years old). Cognition was evaluated with a battery of tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Hemodynamic components of NVC were measured by transcranial Doppler sonography (TCD) during cognitive stimulation, dynamic retinal vessel analysis (DVA) during flicker light stimulation, and functional near infrared spectroscopy (fNIRS) during finger tapping motor task. Cognitive assessments revealed impairments in reaction time and sustained attention after 24 h of SD. Functional NIRS analysis revealed that SD significantly altered hemodynamic responses in the prefrontal cortex and somatosensory cortex during a motor task. NVC-related vascular responses measured by DVA and TCD did not change significantly. Interestingly, TCD detected decreased task-associated cerebral blood flow (CBF) in the right middle cerebral artery in sleep deprived participants. Our results demonstrate that 24 h of SD lead to impairments in cognitive performance together with altered CBF and hemodynamic components of cortical NVC responses.


Subject(s)
Brain/blood supply , Brain/physiopathology , Cerebrovascular Circulation , Cognition , Hemodynamics , Neurovascular Coupling , Sleep Deprivation/complications , Adult , Case-Control Studies , Cerebral Cortex/blood supply , Cerebral Cortex/physiopathology , Female , Humans , Male , Neurons/metabolism , Reaction Time , Spectroscopy, Near-Infrared , Ultrasonography, Doppler, Transcranial , Young Adult
7.
Brain Behav ; 11(8): e02135, 2021 08.
Article in English | MEDLINE | ID: mdl-34156165

ABSTRACT

Sleep deprivation (SD) is known to be associated with decreased cognitive performance; however, the underlying mechanisms are poorly understood. As interactions between distinct brain regions depend on mental state, functional brain networks established by these connections typically show a reorganization during task. Hence, analysis of functional connectivity (FC) could reveal the task-related change in the examined frontal brain networks. Our objective was to assess the impact of SD on static FC in the prefrontal and motor cortices and find whether changes in FC correlate with changes in neuropsychological scores. Healthy young male individuals (n = 10, 27.6 ± 3.7 years of age) participated in the study. A battery of tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) and 48 channel functional near-infrared spectroscopy (fNIRS) measurements were performed before and after 24 hr of SD. Network metrics were obtained by graph theoretical analysis using the fNIRS records in resting state and during finger-tapping sessions. During task, SD resulted in a significantly smaller decrease in the number and strength of functional connections (characterizing FC) in the frontal cortex. Changes in the global connection strengths correlated with decreased performance in the paired association learning test. These results indicate a global impact of SD on functional brain networks in the frontal lobes.


Subject(s)
Motor Cortex , Spectroscopy, Near-Infrared , Brain , Brain Mapping , Humans , Magnetic Resonance Imaging , Male , Sleep Deprivation/diagnostic imaging
8.
Neurophotonics ; 7(3): 035007, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32905073

ABSTRACT

Significance: Deficits in sensorimotor function in persons with type II diabetes mellitus (PwDM) have traditionally been considered a result of peripheral nerve damage. Emerging evidence has suggested that factors outside of nerve damage due to type II diabetes mellitus, such as impaired hemodynamic function, contribute significantly to both sensory and motor deficits in PwDM. Aim: The focus of the current study was to evaluate functional cortical hemodynamic activity during sensory and motor tasks in PwDM. Approach: Functional near-infrared spectroscopy was used to monitor oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) across the cortex during sensory and motor tasks involving the hands. Results: Decline in HbO across sensory and motor regions of interest was found in PwDM with simultaneous deficits in manual motor tasks, providing the first evidence of functional cortical hemodynamic activity deficits relating to motor dysfunction in PwDM. Similar deficits were neither specifically noted in HbR nor during evaluation of sensory function. Health state indices, such as A 1 c , blood pressure, body mass index, and cholesterol, were found to clarify group effects. Conclusions: Further work is needed to clarify potential sex-based differences in PwDM during motor tasks as well as the root of reduced cortical HbO indices but unchanged HbR indices in PwDM.

10.
Anat Rec (Hoboken) ; 302(2): 215-225, 2019 02.
Article in English | MEDLINE | ID: mdl-30412348

ABSTRACT

Maximum jaw gape has important functional implications for behavior and feeding habits in primates. It has been suggested that gape is correlated to canine height and ingested food size. Extending these correlations to the fossil record would provide insights about the diets and/or social behavior of extinct primates. However, this can be problematic due to uncertainty about size and location of musculature, and it depends on reliability and repeatability of maximum gape estimation using only skeletal elements. In this study, maximum bony gape (MBG) was estimated using reliable landmarks and repeatable methods. The cranium was fixed in position and then the mandible was rotated and translated to the point immediately prior to loss of condyle-glenoid contact. Then it was photographed in a steady position using an adjustable wooden frame. This protocol allowed for photographs and linear measurements to be obtained for many museum specimens in a short time. The sample included 203 individuals, representing 42 species of primates. When scaled for body size, linear MBG correlates with maximum anesthetized gape (Hylander: Am J Phys Anthropol 150 (2013) 247-259), ingested food size (Perry and Hartstone-Rose: Am J Phys Anthropol 142 (2010) 625-635), and canine length but not condylar height. Anat Rec, 302:215-225, 2019. © 2018 Wiley Periodicals, Inc.


Subject(s)
Bone Malalignment , Diet/veterinary , Jaw/anatomy & histology , Primates/anatomy & histology , Temporomandibular Joint/anatomy & histology , Animals , Body Size , Female , Jaw/physiology , Male , Mastication , Primates/classification , Primates/physiology , Temporomandibular Joint/physiology
11.
Intest Res ; 16(4): 571-578, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30301333

ABSTRACT

BACKGROUND/AIMS: Medication non-adherence is common in inflammatory bowel diseases (IBD). The short-term consequences of non-adherence include increased disease relapse but the long-term impact upon patients in terms of daily functional impairment are less well characterized. Identifying negative outcomes, such as disability, may encourage adherence. METHODS: Consecutive ambulatory IBD subjects completed the Medication Adherence Rating Scale (MARS; non-adherence defined as ≤16), Inflammatory Bowel Diseases Disability Index (IBD-DI; disability: <3.5) and Beliefs about Medicines Questionnaire (high necessity/concerns: ≥16). The primary outcome was the association between medication non-adherence and disability. Secondary outcomes were the predictors of these outcomes. RESULTS: A total of 173 subjects on IBD maintenance medications were recruited (98 Crohn's disease, 75 ulcerative colitis: median IBD-DI, -5.0; interquartile range [IQR], -14.0 to 4.0 and median MARS, 19.0; IQR, 18 to 20) of whom 24% were non-adherent. Disability correlated significantly with medication non-adherence (r=0.38, P<0.0001). Median IBD-DI for non-adherers was significantly lower than adherers (-16.0 vs. -2.0, P<0.0001). Predictors of disability included female sex (P=0.002), previous hospitalization (P=0.023), management in a referral hospital clinic (P=0.008) and medication concerns (P<0.0001). Non-adherence was independently associated with difficulty managing bowel movements (odds ratio [OR], 3.71; 95% confidence interval [CI], 1.50-9.16, P=0.005), rectal bleeding (OR, 2.69; 95% CI, 1.14-6.36; P=0.024) and arthralgia/arthritis (OR, 2.56; 95% CI, 1.11-5.92; P=0.028). CONCLUSIONS: Medication non-adherence was associated with significantly increased disability in IBD. Female gender, higher disease severity and medication concerns were additional predictors of disability.

12.
J Hum Evol ; 122: 93-107, 2018 09.
Article in English | MEDLINE | ID: mdl-29886006

ABSTRACT

Several new fossil specimens from the Cambay Shale Formation at Tadkeshwar Lignite Mine in Gujarat document the presence of two previously unknown early Eocene primate species from India. A new species of Asiadapis is named based on a jaw fragment preserving premolars similar in morphology to those of A. cambayensis but substantially larger. Also described is an exceptionally preserved edentulous dentary (designated cf. Asiadapis, unnamed sp. nov.) that is slightly larger and much more robust than previously known Cambay Shale primates. Its anatomy most closely resembles that of Eocene adapoids, and the dental formula is the same as in A. cambayensis. A femur and calcaneus are tentatively allocated to the same taxon. Although the dentition is unknown, exquisite preservation of the dentary of cf. Asiadapis sp. nov. enables an assessment of masticatory musculature, function, and gape adaptations, as well as comparison with an equally well-preserved dentary of the asiadapid Marcgodinotius indicus, also from Tadkeshwar. The new M. indicus specimen shows significant gape adaptations but was probably capable of only weak bite force, whereas cf. Asiadapis sp. nov. probably used relatively smaller gapes but could generate relatively greater bite forces.


Subject(s)
Fossils/anatomy & histology , Primates/classification , Animals , Biodiversity , India , Primates/anatomy & histology
13.
Clin Toxicol (Phila) ; 56(9): 856-859, 2018 09.
Article in English | MEDLINE | ID: mdl-29519168

ABSTRACT

BACKGROUND: Recent public health strategies have contributed towards a significant reduction in the incidence of carbon monoxide (CO) poisonings. When events do occur, symptoms can vary dramatically depending on the carboxyhaemoglobin level and individual factors. Most reports to date focus on individual cases or larger retrospective reviews of diverse cohorts. There are very few reports of CO exposure related to scuba diving activities. METHODS: We describe the clinical sequelae experienced by 10 children who were exposed to CO during a scuba diving lesson. We collate patient data in the context of a severely affected individual and employ exponential decay calculations to estimate half-life. RESULTS: Six of the patients exposed to CO were symptomatic. The most severely affected individual suffered multi-organ effects, including myocardial damage, and required intensive care unit admission. The remaining cohort demonstrated notable clinical variability. The half-life of carboxyhaemoglobin on high flow oxygen in this cohort was ∼75 min, in line with previous estimates. CONCLUSION: This work described an uncommon clinical presentation, representing the largest single cohort of its kind. This work exemplifies the variable symptomatology of CO toxicity, of which clinicians should be alert to if patients fall ill after scuba diving.


Subject(s)
Carbon Monoxide Poisoning/physiopathology , Carbon Monoxide/adverse effects , Diving , Adolescent , Cohort Studies , Humans , Male , Retrospective Studies
14.
Anat Rec (Hoboken) ; 301(3): 538-555, 2018 03.
Article in English | MEDLINE | ID: mdl-29418122

ABSTRACT

Our knowledge of muscle anatomy and physiology in vertebrates has increased dramatically over the last two-hundred years. Today, much is understood about how muscles contract and about the functional meaning of muscular variation at multiple scales. Progress in muscle anatomy has profited from the availability of broad comparative samples, advances in microscopy have permitted comparisons at increasingly finer scales, and progress in muscle physiology has profited from many carefully designed and executed experiments. Several avenues of future work are promising. In particular, muscle ontogeny (growth and development) is poorly understood for many vertebrate groups. We consider which types of advances in muscle functional morphology are of use to paleobiologists. These are only a modest subset for muscle anatomy and a very small subset for muscle physiology. The relationship between muscle and bone - spatially and mechanically-is critical to any future advances in "paleomyology". Anat Rec, 301:538-555, 2018. © 2018 Wiley Periodicals, Inc.


Subject(s)
Muscle, Skeletal/anatomy & histology , Muscle, Skeletal/physiology , Paleontology , Vertebrates/anatomy & histology , Vertebrates/physiology , Animals , Biological Evolution , Fossils
15.
Anat Rec (Hoboken) ; 301(2): 343-362, 2018 02.
Article in English | MEDLINE | ID: mdl-29330948

ABSTRACT

The jaw adductor muscles of extinct mammals are often reconstructed to elucidate paleoecological relationships and to make broad comparisons among taxa. Muscle lever arms, bite load arms, muscle dimensions, and gape are often also reconstructed to better understand feeding. Several different approaches to these and related goals are discussed here. A protocol for reconstructing muscle dimensions and bite force using biomechanically informative skull measurements and osteological proxies of muscle dimensions is described and applied to a case study of subfossil Malagasy lemurs. The results of this case study show that most subfossil lemurs emphasized the masseter and medial pterygoid muscles over the temporalis. This supports the inference that these extinct lemurs depended heavily on tough food like leaves. Exceptions include signals of hard-object feeding in Archaeolemur that vary between A. majori and A. edwardsi. Reconstructions of soft-tissue and function are important for understanding past ecological relationships. Even those based on well-supported osteological proxies from extant analogues have limitations for making precise inferences. Anat Rec, 301:343-362, 2018. © 2018 Wiley Periodicals, Inc.


Subject(s)
Bone and Bones/anatomy & histology , Diet , Lemur/anatomy & histology , Masseter Muscle/anatomy & histology , Osteology , Skull/anatomy & histology , Animals , Bone and Bones/physiology , Ecology , Fossils , Lemur/physiology , Masseter Muscle/physiology , Phylogeny , Skull/physiology
16.
Anat Rec (Hoboken) ; 301(2): 227-255, 2018 02.
Article in English | MEDLINE | ID: mdl-29330956

ABSTRACT

Phalangeriform marsupials have often been compared with primates because of similarity in the range of external morphology, ecological niches, and body size between the two radiations. We explore morphological convergence in the masticatory anatomy of strepsirrhine primates and phalangeriforms, through osteological measurements of the mandible and facial skeleton, and through dissection of the masticatory musculature, presenting new data on the arrangement and proportions of jaw adductors in phalangeriforms. Phalangeriforms and primates have a large number of shape differences in mandibular morphology. Despite these differences in shape on phylogenetic lines, dietary groups used to pool species of phalangeriforms and strepsirrhines also differed from each other in a range of shape variables. Notably, the striped possum (Dactylopsila), previously described as convergent with the aye-aye (Daubentonia), shares a number of features of mandibular shape with Daubentonia, and the exudate-feeding sugar-glider, Petaurus, shares shape features with gummivorous strepsirrhines. Petaurus also has long-fibered jaw adductors for its body mass, as would be expected for a species with a requirement for large gape. Phalangeriform species on the frugivore-folivore continuum were less clearly comparable to strepsirrhine species with similar diets. There are a number of significant dietary contrasts in osteological measurements, but in the masticatory muscles phalangeriforms did not meet all expectations based on available dietary data, highlighting the possible complexity of dietary adaptation in phalangeriform folivores. Anat Rec, 301:227-255, 2018. © 2018 Wiley Periodicals, Inc.


Subject(s)
Adaptation, Physiological , Feeding Behavior/physiology , Jaw/physiology , Mandible/physiology , Marsupialia/physiology , Masticatory Muscles/physiology , Primates/physiology , Animals , Biomechanical Phenomena , Body Size , Diet , Jaw/anatomy & histology , Mandible/anatomy & histology , Marsupialia/anatomy & histology , Masticatory Muscles/anatomy & histology , Phylogeny , Primates/anatomy & histology
17.
Anat Rec (Hoboken) ; 301(2): 291-310, 2018 02.
Article in English | MEDLINE | ID: mdl-29330958

ABSTRACT

Despite great interest and decades of research, the musculoskeletal relationships of the masticatory system in primates are still not fully understood. However, without a clear understanding of the interplay between muscles and bones it remains difficult to understand the functional significance of morphological traits of the skeleton. Here, we aim to study the impacts of the masticatory muscles on the shape of the cranium and the mandible as well as their co-variation in strepsirrhine primates. To do so, we use 3D geometric morphometric approaches to assess the shape of each bone of the skull of 20 species for which muscle data are available in the literature. Impacts of the masticatory muscles on the skull shape were assessed using non-phylogenetic regressions and phylogenetic regressions whereas co-variations were assessed using two-blocks partial least square (2B-PLS) and phylogenetic 2B-PLS. Our results show that there is a phylogenetic signal for skull shape and masticatory muscles. They also show that there is a significant impact of the masticatory muscles on cranial shape but not as much as on the mandible. The co-variations are also stronger between the masticatory muscles and cranial shape even when taking into account phylogeny. Interestingly, the results of co-variation between the masticatory muscles and mandibular shape show a more complex pattern in two different directions to get strong muscles associated with mandibular shape: a folivore way (with the bamboo lemurs and sifakas) and a hard-object eater one (with the aye-aye). Anat Rec, 301:291-310, 2018. © 2018 Wiley Periodicals, Inc.


Subject(s)
Jaw/anatomy & histology , Masticatory Muscles/anatomy & histology , Musculoskeletal System/anatomy & histology , Skull/anatomy & histology , Strepsirhini/anatomy & histology , Animals , Biological Evolution , Biomechanical Phenomena , Jaw/physiology , Masticatory Muscles/physiology , Phylogeny , Skull/physiology , Strepsirhini/physiology
18.
PLoS One ; 13(1): e0190689, 2018.
Article in English | MEDLINE | ID: mdl-29324822

ABSTRACT

We analyzed feeding biomechanics in pitheciine monkeys (Pithecia, Chiropotes, Cacajao), a clade that specializes on hard-husked unripe fruit (sclerocarpy) and resistant seeds (seed predation). We tested the hypothesis that pitheciine crania are well-suited to generate and withstand forceful canine and molar biting, with the prediction that they generate bite forces more efficiently and better resist masticatory strains than the closely-related Callicebus, which does not specialize on unripe fruits and/or seeds. We also tested the hypothesis that Callicebus-Pithecia-Chiropotes-Cacajao represent a morphocline of increasing sclerocarpic specialization with respect to biting leverage and craniofacial strength, consistent with anterior dental morphology. We found that pitheciines have higher biting leverage than Callicebus and are generally more resistant to masticatory strain. However, Cacajao was found to experience high strain magnitudes in some facial regions. We therefore found limited support for the morphocline hypothesis, at least with respect to the mechanical performance metrics examined here. Biting leverage in Cacajao was nearly identical (or slightly less than) in Chiropotes and strain magnitudes during canine biting were more likely to follow a Cacajao-Chiropotes-Pithecia trend of increasing strength, in contrast to the proposed morphocline. These results could indicate that bite force efficiency and derived anterior teeth were selected for in pitheciines at the expense of increased strain magnitudes. However, our results for Cacajao potentially reflect reduced feeding competition offered by allopatry with other pitheciines, which allows Cacajao species to choose from a wider variety of fruits at various stages of ripeness, leading to reduction in the selection for robust facial features. We also found that feeding biomechanics in sympatric Pithecia and Chiropotes are consistent with data on food structural properties and observations of dietary niche separation, with the former being well-suited for the regular molar crushing of hard seeds and the latter better adapted for breaching hard fruits.


Subject(s)
Diet , Ecosystem , Feeding Behavior , Mastication , Primates/physiology , Seeds , Animals
19.
J Hum Evol ; 115: 20-35, 2018 02.
Article in English | MEDLINE | ID: mdl-29150186

ABSTRACT

Body mass is an important component of any paleobiological reconstruction. Reliable skeletal dimensions for making estimates are desirable but extant primate reference samples with known body masses are rare. We estimated body mass in a sample of extinct platyrrhines and Fayum anthropoids based on four measurements of the articular surfaces of the humerus and femur. Estimates were based on a large extant reference sample of wild-collected individuals with associated body masses, including previously published and new data from extant platyrrhines, cercopithecoids, and hominoids. In general, scaling of joint dimensions is positively allometric relative to expectations of geometric isometry, but negatively allometric relative to expectations of maintaining equivalent joint surface areas. Body mass prediction equations based on articular breadths are reasonably precise, with %SEEs of 17-25%. The breadth of the distal femoral articulation yields the most reliable estimates of body mass because it scales similarly in all major anthropoid taxa. Other joints scale differently in different taxa; therefore, locomotor style and phylogenetic affinity must be considered when calculating body mass estimates from the proximal femur, proximal humerus, and distal humerus. The body mass prediction equations were applied to 36 Old World and New World fossil anthropoid specimens representing 11 taxa, plus two Haitian specimens of uncertain taxonomic affinity. Among the extinct platyrrhines studied, only Cebupithecia is similar to large, extant platyrrhines in having large humeral (especially distal) joints. Our body mass estimates differ from each other and from published estimates based on teeth in ways that reflect known differences in relative sizes of the joints and teeth. We prefer body mass estimators that are biomechanically linked to weight-bearing, and especially those that are relatively insensitive to differences in locomotor style and phylogenetic history. Whenever possible, extant reference samples should be chosen to match target fossils in joint proportionality.


Subject(s)
Body Weight , Catarrhini/anatomy & histology , Catarrhini/physiology , Fossils , Platyrrhini/anatomy & histology , Platyrrhini/physiology , Animals , Biological Evolution , Body Size , Femur/anatomy & histology , Fossils/anatomy & histology , Humerus/anatomy & histology
20.
Inflamm Bowel Dis ; 23(8): 1257-1261, 2017 08.
Article in English | MEDLINE | ID: mdl-28719539

ABSTRACT

BACKGROUND: While inflammatory bowel diseases (IBD) require long-term medication usage to maintain remission, nonadherence is common and adversely associated with poorer clinical outcomes. Personalized IBD Pharmacist Adherence Counselling, based on the Health Beliefs Model of medication perception, may increase medication adherence. METHODS: This prospective multi-center longitudinal parallel study recruited consecutive IBD subjects that were classified as baseline medication non-adherers and adherers. Non-adherers received a single IBD Pharmacist Adherence Counselling intervention at baseline, while adherers served as controls. Medication Adherence Report Scale and Beliefs about Medicines Questionnaire were administered up to 24 months. Medication acceptance was defined as high perception of medication necessity with low concerns. The primary endpoint was medication adherence at 24 months. RESULTS: Of 114 subjects approached, 100 completed follow-up, with 36 being baseline nonadherers (median Medication Adherence Report Scale = 15.0) and 64 baseline adherers (median Medication Adherence Report Scale = 19.0; P < 0.001). At 24 months, nonadherence in the IBD Pharmacist Adherence Counselling group decreased from 100% to 44.4% (P = 0.001), whereas nonadherence in controls remained unchanged (P = 0.38). Individually, Beliefs about Medicines Questionnaire Necessity and Concern scores showed no significant changes in both groups, but medication acceptance significantly improved in baseline nonadherers at 12 months (P = 0.031) with a trend toward durable improvement at 24 months (P = 0.063). CONCLUSIONS: Medication nonadherence in IBD can be improved through a single personalized counseling session by an IBD pharmacist, and the benefit was durable for 2 years. This benefit was through improving the acceptance of medication.


Subject(s)
Colitis, Ulcerative/drug therapy , Counseling/methods , Crohn Disease/drug therapy , Health Knowledge, Attitudes, Practice , Medication Adherence , Pharmacists , Adolescent , Adult , Aged , Colitis, Ulcerative/psychology , Crohn Disease/psychology , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Middle Aged , Prognosis , Prospective Studies , Surveys and Questionnaires , Young Adult
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