scholarly journals Powered flight in hatchling pterosaurs: evidence from wing form and bone strength

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Darren Naish ◽  
Mark P. Witton ◽  
Elizabeth Martin-Silverstone
Keyword(s):  
Bone Strength ◽  
Bending Strength ◽  
Early Model ◽  
Adult Size ◽  
Older Individuals ◽  
Cluttered Environments ◽  
Aspect Ratios ◽  
Late Model ◽  
Independent Life ◽  
Using Data

AbstractCompeting views exist on the behaviour and lifestyle of pterosaurs during the earliest phases of life. A ‘flap-early’ model proposes that hatchlings were capable of independent life and flapping flight, a ‘fly-late’ model posits that juveniles were not flight capable until 50% of adult size, and a ‘glide-early’ model requires that young juveniles were flight-capable but only able to glide. We test these models by quantifying the flight abilities of very young juvenile pterosaurs via analysis of wing bone strength, wing loading, wingspan and wing aspect ratios, primarily using data from embryonic and hatchling specimens of Pterodaustro guinazui and Sinopterus dongi. We argue that a young Sinopterus specimen has been mischaracterised as a distinct taxon. The humeri of pterosaur juveniles are similar in bending strength to those of adults and able to withstand launch and flight; wing size and wing aspect ratios of young juveniles are also in keeping with powered flight. We therefore reject the ‘fly-late’ and ‘glide-early’ models. We further show that young juveniles were excellent gliders, albeit not reliant on specialist gliding. The wing forms of very young juveniles differ significantly from larger individuals, meaning that variation in speed, manoeuvrability, take-off angle and so on was present across a species as it matured. Juveniles appear to have been adapted for flight in cluttered environments, in contrast to larger, older individuals. We propose on the basis of these conclusions that pterosaur species occupied distinct niches across ontogeny.

scholarly journals Fruit and Vegetable Knowledge and Intake within an Australian Population: The AusDiab Study

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3628
Author(s):  
Caroline R. Hill ◽  
Lauren C. Blekkenhorst ◽  
Simone Radavelli-Bagatini ◽  
Marc Sim ◽  
Richard J. Woodman ◽  
...  
Keyword(s):  
Health Promotion ◽  
Vegetable Intake ◽  
Lifestyle Factors ◽  
Maximal Effect ◽  
Older Individuals ◽  
Fruit And Vegetable ◽  
Balanced Diet ◽  
Adequate Knowledge ◽  
Insufficient Physical Activity ◽  
Using Data

Understanding the relationship between fruit and vegetable knowledge (FVK) and fruit and vegetable intake (FVI) is an important consideration for improved public health and successful targeting of health promotion messaging. The aim of this study was to investigate the association between FVK and FVI in Australian adults and to identify subgroups most at risk of poor knowledge. Using data from the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab), we investigated associations between FVK and FVI, as well as demographic and lifestyle factors. Baseline FVK was measured using two self-reported questions. FVI was assessed using a validated, self-reported, food frequency questionnaire in 1999/00 (baseline), 2004/05, and 2011/12. Amongst the 8966 participants assessed at baseline, 24.1% had adequate, 73.0% had insufficient, and 2.9% had poor FVK. Using linear regression, those with insufficient or poor FVK reported significantly lower FVI (grams/day) compared to those with adequate FVK: baseline (coefficient (95%CI)): −67.1 (−80.0, −54.3) and −124.0 (−142.9, −105.1), respectively, whilst, at 12 years, the differences were −42.5 (−54.6, −30.5) and −94.6 (−133.8, −55.5) grams/day, respectively (all p < 0.001). Poor FVK was more likely to be reported in males, older individuals (>65 years), socio-economically disadvantaged, smokers, and those with insufficient physical activity/sedentary behavior. We demonstrate that having adequate knowledge of FVI, defined as knowing to consume fruit and vegetables several times a day for a well-balanced diet, is strongly associated with FVI, with several demographic and lifestyle factors predicting FVK. Health promotion messages aimed at increasing FVK should target these subgroups for maximal effect.

scholarly journals An obstacle disturbance selection framework: emergent robot steady states under repeated collisions

2020 ◽  
Vol 39 (13) ◽  
pp. 1549-1566
Author(s):  
Feifei Qian ◽  
Daniel E Koditschek
Keyword(s):  
Horizontal Plane ◽  
Robot Dynamics ◽  
Natural Environments ◽  
Complex Environments ◽  
Cluttered Environments ◽  
Robot Trajectory ◽  
Aspect Ratios ◽  
The Face ◽  
Selection Framework ◽  
Contact Position

Natural environments are often filled with obstacles and disturbances. Traditional navigation and planning approaches normally depend on finding a traversable “free space” for robots to avoid unexpected contact or collision. We hypothesize that with a better understanding of the robot–obstacle interactions, these collisions and disturbances can be exploited as opportunities to improve robot locomotion in complex environments. In this article, we propose a novel obstacle disturbance selection (ODS) framework with the aim of allowing robots to actively select disturbances to achieve environment-aided locomotion. Using an empirically characterized relationship between leg–obstacle contact position and robot trajectory deviation, we simplify the representation of the obstacle-filled physical environment to a horizontal-plane disturbance force field. We then treat each robot leg as a “disturbance force selector” for prediction of obstacle-modulated robot dynamics. Combining the two representations provides analytical insights into the effects of gaits on legged traversal in cluttered environments. We illustrate the predictive power of the ODS framework by studying the horizontal-plane dynamics of a quadrupedal robot traversing an array of evenly-spaced cylindrical obstacles with both bounding and trotting gaits. Experiments corroborate numerical simulations that reveal the emergence of a stable equilibrium orientation in the face of repeated obstacle disturbances. The ODS reduction yields closed-form analytical predictions of the equilibrium position for different robot body aspect ratios, gait patterns, and obstacle spacings. We conclude with speculative remarks bearing on the prospects for novel ODS-based gait control schemes for shaping robot navigation in perturbation-rich environments.

Health Shocks and Initiation of Use of Preventive Services Among Older Adults

2016 ◽  
Vol 37 (7) ◽  
pp. 856-880
Author(s):  
Boon Peng Ng ◽  
Gail A. Jensen
Keyword(s):  
Prostate Cancer ◽  
Older Adults ◽  
Preventive Services ◽  
Pap Smears ◽  
Older Individuals ◽  
Health Shock ◽  
Cancer Screenings ◽  
History Of ◽  
Health Event ◽  
Using Data

This article examines whether adverse changes to health or functioning serve as an impetus to begin using preventive services among older individuals with a history of non-use. Using data from the 1998-2008 Health and Retirement Study, the use of mammograms, pap smears, prostate cancer screenings, cholesterol checks, and flu shots is examined among 2,975 self-reported non-users of such services. Older women who experience a health shock are 1.86, 1.50, 1.79, and 1.46 times more likely to begin getting mammograms, pap smears, cholesterol checks, and flu shots, respectively. Older men who experience a health shock are 2.24, 2.72, and 1.64 times more likely to begin getting prostate cancer screenings, cholesterol checks, and flu shots, respectively. All of these results are statistically significant. Thus, older adults often improve their health behaviors after experiencing an adverse health event.

scholarly journals High Fat Diet-Induced Obesity Negatively Affects Whole Bone Bending Strength but not Cortical Structure in the Femur

2019 ◽  
Author(s):  
Nicholas J. Hanne ◽  
Andrew J. Steward ◽  
Jason M. Cox ◽  
Elizabeth D. Easter ◽  
Hannah L. Thornburg ◽  
...  
Keyword(s):  
Bone Strength ◽  
Blood Supply ◽  
Material Properties ◽  
High Fat Diet ◽  
Bending Strength ◽  
Tissue Level ◽  
High Fat ◽  
Mineral Density ◽  
Femoral Metaphysis ◽  
Diet Induced Obesity

AbstractAlthough body mass index is positively associated with bone mineral density, suggesting obesity is protective against fracture, elderly obese individuals experience greater fracture risk at certain sites than non-obese peers, suggesting bone structural or material changes contribute to fragility. Diet-induced obesity rodent studies have reported detrimental changes to bone microstructure and some apparent-level material properties, but tissue-level material changes are not well understood. Because adipose tissue is highly vascularized, and bone remodeling depends critically on functional vascular supply, concurrent effects on osteovascular perfusion and structure may provide insight about obesity-related bone fragility. This study aimed to determine the effects of obesity on both tissue-level bone properties and osteovascular properties that could negatively impact bone strength. Five-week-old male C57Bl/6J mice were fed either high fat diet (HFD) or control fat diet (CFD) for 17 weeks and received daily treadmill exercise or remained sedentary for eight weeks at ages 14-22 weeks. HFD negatively affected femur bending strength, with 18% lower yield load than CFD. Although HFD negatively altered cancellous microstructure in the distal femur, with 32% lower bone volume fraction than CFD, it did not affect cortical bone geometry in the femoral metaphysis or diaphysis. HFD caused increased carbonate substitution but had no effect on other composition metrics or apparent- or tissue-level material properties in the femoral diaphysis. Exercise did not affect bone strength or microstructure but increased endosteal mineralizing surface in the tibial diaphysis, mineral crystallinity and mineral-to-matrix ratio in the femur, and blood supply to the proximal tibial metaphysis. HFD did not affect blood supply in the tibia or 2D osteovascular structure in the distal femoral metaphysis, indicating that HFD negatively affects cancellous bone without affecting osteovasculature. This study reveals that HFD negatively affected cancellous microstructure without affecting osteovascular structure, and whole-bone strength without altering cortical geometry or material properties.

scholarly journals Glide analysis and bone strength tests indicate powered flight capabilities in hatchling pterosaurs

2017 ◽  
Author(s):  
Mark P Witton ◽  
Elizabeth Martin-Silverstone ◽  
Darren Naish
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Bone Strength ◽  
Bending Strength ◽  
Skeletal Development ◽  
Maximum Size ◽  
Strength Analysis ◽  
Life Stages ◽  
Strength Tests ◽  
Very High

Pterosaur embryos and ‘hatchling’ specimens show a surprising level of skeletal development including well-ossified skeletons and large wings. This has prompted interpretations of pterosaurs as being flight-capable from the earliest ontogenetic stages, contrasting them against the majority of other flying animals, living or extinct. Though popular, this hypothesis is not universally accepted. Some authors propose that pterosaurs only became flight capable once they reached 50% of maximum size, explaining a slowing of growth rate in later ontogeny as metabolic resources were diverted into an energy-demanding form of locomotion. We investigated these hypotheses through glide performance and wing bone strength analysis on hatchling-grade specimens of two pterosaurs, Pterodaustro guinazui and Sinopterus dongi. We found that hatchling pterosaurs were excellent gliders, but with a wing ecomorphology more comparable to powered fliers than obligate gliders. Bone strength analysis shows that hatchling pterosaur wing bones are structurally identical to those of larger pterosaurs and – because of their very low body masses – their bending strength relative to body weight is very high, comparable to or exceeding the greatest values estimated for larger, more mature pterosaurs. Hatchling pterosaurs are thus as mechanically adapted to powered flight stresses as other pterosaurs, if not moreso. Together with our glide tests, this result supports interpretations of hatchling pterosaurs as flight-capable. Size differences between pterosaur hatchlings and larger members of their species dictate differences in wing ecomorphology and flight capabilities at different life stages, which might have bearing on pterosaur ontogenetic niching.

scholarly journals Caregivers' Cannabis Use: Does Burden Lead to Blunts?

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 511-511
Author(s):  
Kanika Arora
Keyword(s):  
Health Behaviors ◽  
Marijuana Use ◽  
Informal Caregiving ◽  
Care Recipient ◽  
Behavioral Risk ◽  
Older Individuals ◽  
Multivariable Logistic Regression Model ◽  
Behavioral Risk Factor Surveillance ◽  
Risk Factor Surveillance ◽  
Using Data

Abstract Research on risky health behaviors among caregivers is limited. In this paper, we examine the association between informal caregiving and marijuana use and whether this association varies by age. Using data from Behavioral Risk Factor Surveillance System (2016-2019), a multivariable logistic regression model compared marijuana use in “caregivers” and “expectant caregivers.” We stratified the analyses by age and also assessed the association between caregiving intensity and marijuana use. Among younger individuals (18-49 years), informal caregiving was associated with higher odds of marijuana use. In this group, higher prevalence of marijuana use was positively associated with care intensity. There was no detectable association between caregiving and marijuana use among older individuals (50 years or older). Health behaviors among caregivers differ by age. Combined exposure to informal caregiving and marijuana in young adulthood may lead to adverse long-term health consequences. Immediate effects of marijuana use may negatively influence care recipient outcomes.

scholarly journals Low Friend Connection Leads to Low Functional Capacity of Older Adults: Findings From a 2-year Longitudinal Study

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 925-926
Author(s):  
Mai Takase ◽  
Kyo Takahashi ◽  
Ryogo Ogino ◽  
Tomoki Tanaka ◽  
Jun Goto ◽  
...  
Keyword(s):  
Older Adults ◽  
Longitudinal Study ◽  
Functional Capacity ◽  
Reference Group ◽  
Personal Connection ◽  
Significant Difference ◽  
Personal Connections ◽  
Independent Life ◽  
Japanese Older Adults ◽  
Using Data

Abstract Maintaining personal connections in geriatric years is important to sustain the functional capacity of older adults. In this study, we define the term functional capacity as the ability to perform tasks and activities necessary for one’s independent life. Meanwhile, the type of personal connection and its effect on functional capacity remain unclear. We classified personal connections into connections with family or friends and examined their association with the functional capacity of independently living Japanese older adults. A two-year longitudinal study (2016 and 2018) was conducted using data from the Kashiwa Cohort Study. The amount of personal connections was determined using the Lubben Social Network Scale. The Japan Science and Technology Agency Index of Competence was used to assess participants’ functional capacity. The change in functional capacity was analyzed by binomial logistic regression analysis (N=638, reference: group with high family and friend connection). The results showed a decline in the functional capacity of the group with low friend and family connections (odds ratio (OR): 0.48, 95%CI: 0.29–0.82). This trend was also seen for the group with a high family connection but low friend connection (OR: 0.43, 95%CI: 0.24–0.78). Meanwhile, there was no significant difference between the reference group and the group with low family but high friend connection (OR: 0.85, 95%CI: 0.47–1.56). The results imply the importance of having a friend for sustainable functional capacity in old age. Interventions that facilitate friend-to-friend interactions or promote new friendships among older adults can be considered as support strategies.

scholarly journals Alcohol-Related Deaths and Hospitalizations by Race, Gender, and Age in California

2010 ◽  
Vol 3 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Mandy Stahre ◽  
Michele Simon
Keyword(s):  
Alcohol Use ◽  
Race And Ethnicity ◽  
Motor Vehicle ◽  
The United States ◽  
Chronic Illnesses ◽  
Older Individuals ◽  
Gender And Age ◽  
Excessive Alcohol ◽  
Race Ethnicity ◽  
Using Data

Introduction: Excessive alcohol use is the third leading preventable cause of death in the United States each year and responsible for about 10,000 deaths in California alone. In addition, excessive alcohol use is responsible for many hospitalizations due to injuries and illnesses. Alcohol consumption is known to differ by age, sex, and race/ethnicity and these consumption patterns can lead to differences in alcohol-related outcomes. Methods: Using data from a variety of sources, alcohol-attributable deaths and nonfatal hospitalizations for illnesses and injuries were calculated for California for the year 2006. Results: Excessive alcohol use resulted in over 10,000 deaths and 72,000 nonfatal hospitalizations in California. The majority of consequences (51%) were due to chronic illnesses associated with long-term excessive use of alcohol. Overall, males reported more deaths and nonfatal hospitalizations due to excessive alcohol use than women. Alcohol-attributable deaths and hospitalizations are more likely to occur among individuals aged 50-64 years for illnesses and individuals aged 20-34 years for injuries. Older individuals suffered from more chronic conditions such as alcoholic liver disease, while younger individuals were more likely to suffer from injuries, the most common being motor-vehicle traffic crashes. Significant differences in the rate of deaths and nonfatal hospitalizations by race/ethnicity were more common due to injuries and violence than chronic diseases. Conclusions: This study highlighted key findings of demographic differences in consequences suffered by excessive alcohol use in California. Continued efforts to better evaluate the contribution of alcohol to morbidity and mortality by demographic factors, especially by race and ethnicity, is warranted to prevent and reduce the harm associated with this behavior.

Evaluation of Decalcification Induced Changes in Bone Strength Using Electrical Conductivity Measurements

2014 ◽  
Author(s):  
Vladislav Sevostianov
Keyword(s):  
Electrical Resistivity ◽  
Electrical Properties ◽  
Cortical Bone ◽  
Young’S Modulus ◽  
Bone Strength ◽  
Acid Treatment ◽  
Bending Strength ◽  
Young's Modulus ◽  
Testing Machine ◽  
Mechanical And Electrical Properties

The paper focuses on the effect of decalcification on microstructure and the mechanical and electrical properties of cortical bone. Decalcification is produced by placing the specimens into 5% vinegar acid for 72 hours. This acid treatment leads to a decrease in mass of the specimens 7.78 % (averaged over ten acid treated specimens). Microstructure of natural bone and acid treated bone is then compared using confocal microscopy. To estimate effect of acid treatment on electrical resistivity of bone, the specimens are rinsed and saturated with 0.9% NaCl solution for ten minutes. Then electrical resistance is measured by the four-point method and electrical resistivity is calculated. Averaging over ten acid treated specimens and ten control specimens show that decalcification lead to increase of electrical resistivity 5.85 times. Comparison of mechanical properties of natural and acid treated bones is done by three point bending using Instron 5882 testing machine. It is observed that 7.78 % mass loss in cortical bone yields reduction of the Young’s modulus about 2.7 times and bending strength of the specimens by 35%. A positive correlation between change in strength and Young’s modulus and electrical resistivity of the individual specimens is observed. The obtained results allows one to estimate changes in mechanical and electrical properties of bone from known losses in bone mass and, thus, non-destructively evaluate the decrease in bone strength through changes in electrical resistivity.

The Changing Face of Debt and Financial Fragility at Older Ages

2018 ◽  
Vol 108 ◽  
pp. 407-411 ◽  
Author(s):  
Annamaria Lusardi ◽  
Olivia S. Mitchell ◽  
Noemi Oggero
Keyword(s):  
Policy Implications ◽  
Financial Fragility ◽  
Health And Retirement Study ◽  
Older Individuals ◽  
Older Americans ◽  
Down Payments ◽  
Using Data ◽  
Retirement Study

We investigate changes in older individuals' financial fragility as they stand on the verge of retirement. Using data from the Health and Retirement Study (HRS), we compare how debt has changed for successive cohorts of people age 56–61. Our analysis shows that recent older Americans close to retirement hold more debt, and hence face greater financial insecurity, than earlier generations. This is primarily due to having bought more expensive homes with smaller down payments. We discuss possible policy implications.

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