Estimation of Bone Matrix Apparent Stiffness Variation Caused by Osteocyte Lacunar Size and Density

2000 ◽  
Vol 123 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Yener N. Yeni ◽  
Deepak Vashishth ◽  
David P. Fyhrie

The role of osteocyte lacunar size and density on the apparent stiffness of bone matrix was predicted using a mechanical model from the literature. Lacunar size and lacunar density for different bones from different gender and age groups were used to predict the range of matrix apparent stiffness values for human cortical and cancellous tissue. The results suggest that bone matrix apparent stiffness depends on tissue type (cortical versus cancellous), age, and gender, the magnitudes of the effects being significant but small in all cases. Males had a higher predicted matrix apparent stiffness than females for vertebral cancellous bone p<10−7)and the difference increased with age p=0.0007. In contrast, matrix apparent stiffness was not different between males and females for femoral cortical bone and increased with age in both males p<0.0001 and females p<0.0364. Osteocyte lacunar density and size may cause significant gender and age-related variations in bone matrix apparent stiffness. The magnitude of variations in matrix apparent stiffness was small within the physiological range of lacunar size and density for healthy bone, whereas the variations can be profound in certain pathological cases. It was proposed that the mechanical effects of osteocyte density be uncoupled from their biological effects by controlling lacunar size in normal bone.

2017 ◽  
Vol 27 (1) ◽  
pp. 97-113 ◽  
Author(s):  
Andrei Ion ◽  
Christopher D. Nye ◽  
Dragoş Iliescu

Gender- and age-related differences in the variability of various human attributes and abilities have been investigated. This article investigates the age and gender differences in the variability of Holland’s six vocational dimensions with a sample including 1,519 participants, divided into four age groups: early adolescence (12–15 years old), adolescence (16–20 years old), young adulthood (21–30 years old), and adulthood (31–59 years old). The results showed nontrivial differences in the variability of vocational interests across gender and age groups alike. Although significant differences in variability were observed for all vocational interest dimensions except investigative, the most pronounced differences in variability across age and gender were observed for realistic and conventional dimensions. Generally, the observed differences in variability were larger in adolescence than in adulthood. Overall, vocational interests displayed less differentiation within the younger age groups (early adolescence and early adulthood) as compared to adulthood.


Author(s):  
Seda SERTEL MEYVACI ◽  
Yasin Emre KAYA

Objectives: The objective of our study was to examine the changes in the inclination and Alsberg angles of the femur in terms of age and gender. Methods: The present study was conducted on X-Ray images of 208 healthy individuals (103 males and 105 females) admitted to Bolu Abant Izzet Baysal University, Orthopedics and Traumatology Clinics. Both genders were separated into 3 different age groups. Statistical analyses were made to determine the difference between the gender and age groups. Results: The mean inclination angle of the femur was 132.88±7.08º on the right-side and 130.27±7.81º on the left. The mean Alsberg angle of the femur was 42.07±7.04º on the right-side and 41.43±7.03º on the left. The inclination angle was significantly higher in males than females on both sides and was significantly lower in 41–60 age group. The Alsberg angle was also significantly higher in males than females in 21–40 age group. Conclusion: The Alsberg angle is positively related with inclination angle, and subject to change by age. Knowing how IA and AA will be affected by age and gender and knowing the relation between these two angles will help to take a more accurate approach while evaluating and managing the follow up of a patient undergoing total hip arthroplasty, reconstructive surgery or planning physical theraphy.


Author(s):  
Daniele Miano

This book focuses on the Latin goddess Fortuna, one of the better known deities in ancient Italy. The earliest forms of her worship can be traced back to archaic Latium, and she was still a widely recognized allegorical figure during the Middle Ages and the Renaissance. The main reason for her longevity is that she was a conceptual deity, and had strong associations with chance and good fortune. When they were interacting with the goddess, communities, individuals, and gender and age groups were inevitably also interacting with the concept. These relations were not neutral: they allowed people to renegotiate the concept, enriching it with new meanings and challenging established ones. The geographical and chronological scope of this book is Italy from the archaic age to the late Republic. In this period Italy was a fragmented, multicultural and multilinguistic environment, characterized by a wide circulation of people, customs, and ideas, in which Rome played an increasingly dominant role. All available sources on Fortuna have been used: literary, epigraphic, and archaeological. The study of the goddess based on conceptual analysis will serve to construct a radically new picture of the historical development of this deity in the context of the cultural interactions taking place in ancient Italy. The book also aims at experimenting with a new approach to polytheism, based on the connection between gods and goddesses and concepts.


Author(s):  
Tongmei Duan ◽  
Xun Chen ◽  
Jing Wu ◽  
Ronghai Li ◽  
Huijuan Guo ◽  
...  

Objective: Carbohydrate antigen 72-4 (CA72-4) is widely used in the diagnosis and monitoring of many cancers. However, there are few studies on the differences of CA72-4 levels in terms of age and gender. Methods: 10957 healthy subjects were divided into two groups according to gender and three age groups. The serum CA72-4 were detected. Statistical analysis was performed by SPSS. Results: The CA72-4 level in female group was significantly higher than that in male group. The level of CA72-4 gradually decreased with age. Compared with the age >60 group, the CA72-4 levels were increased in the age 46-60 group and 16-45 group (P >0.05, respectively). To better observe the age difference, the age 16-45 and 46–60 group were combined into the age 16-60 group. In comparison to the age >60 group, the CA72-4 level of age 16-60 group was significantly increased (P =0.000). In the age >60 group, there was no difference between genders. Nevertheless, the difference between the sexes in the age 16-60 group was significant (P =0.023). Conclusions: The reference interval of CA72-4 for local healthy population was established. CA72-4 levels gradually decreased with the increase of age, and CA72-4 level in females aged 16-60 years (0-18.0 U/mL) was higher than in males (0-14.5 U/mL), however there was no gender difference in the age group above 60 years old (0-14.5 U/mL). Moreover, male CA72-4 was no significant difference among all age groups, while the potential mechanism of female changes with age needed further study.


2018 ◽  
Vol 6 ◽  
pp. 296-302
Author(s):  
Agnieszka Leszczynska

This article discusses issues related to organizational commitment and work related values. The research problem focuses on the correlation between values related to professional work and the affective, normative and calculative commitment of employees. A research question was posed as to what work related values are correlated with organisational commitment. The article presents the results of an empirical study conducted on a group of 2076 people with the use of a diagnostic survey. The obtained data were analysed relative to the gender and age of the respondents. The results indicate certain discrepancies in terms of the value hierarchies observable between employees of different ages. Both men and women selected work-life balance and security as their most important values. The level of commitment was comparable between representatives of the two genders, with the levels observed for normative commitment. Organisational commitment increased with age and was statistically different for the respective age groups. The study confirmed the correlation between the hierarchy of work related values and the level of commitment, as well as the discrepancies in this respect between the respective age and gender groups. The same suggests that there is a need to account for values held by the employees when developing and employing motivational systems and HR practices.


Author(s):  
Z Hu ◽  
GCW Man ◽  
KH Yeung ◽  
WH Cheung ◽  
WCW Chu ◽  
...  

To establish the age- and sex-related normative values of sagittal alignment in asymptomatic Chinese adults, and to investigate the changes and possible associated compensation mechanisms across age groups. 584 asymptomatic Chinese adults aged 20–89 years were recruited. Subjects were grouped according to age and gender. Whole-body standing radiographs were acquired for evaluating sagittal alignment from spine to lower limb. Sagittal parameters between gender in different age groups were compared via independent t test. Pearson correlation analysis was used to demonstrate relationships between parameters. Thoracic kyphosis (TK) increased steadily while lumbar lordosis decreased gradually in both genders. Pelvic tilt (PT) in male is greater than in female across all age groups with age related gradual increase. There were significant differences between male and female from 20s to 60s in terms of knee flexion angle (KA) and ankle dorsiflexion angle (AA), but the differences were not significant after 60s. T1 pelvic angle (TPA) was significantly correlated with spinal, pelvic and lower-limb alignment. The older group (≥50 years) had a stronger correlation of TPA with PT and KA, whereas the younger (<50 years) had stronger correlation with TK. This study comprehensively presented the normative sagittal alignment based on a large asymptomatic population, which could serve as an age- and gender-specific reference value for spine surgeons when planning for correction surgery. Age can influence the recruitment of compensation mechanism that involve more pelvic and lower limb mechanisms for elderly people.


1977 ◽  
Vol 232 (6) ◽  
pp. E580
Author(s):  
M P Zabinski ◽  
P Biancani

Longitudinal force-length relationship of the rat esophagus was studied in vitro in three age groups: 1 mo, 3 mo, and 12 mo. The length of maximum force development (MFD) occurs at 1.4-1.5 times the in vivo length for all age groups. The active force developed at MFD increases markedly with age. The difference in the active forces in the 3-mo and 12-mo age groups is due to differences in cross section because the active stress of the esophagus in the longitudinal direction is approximately equal for the two age groups. The active stress in the 1-mo-old rats is lower than in the 3-mo-old rats, suggesting an increased contractility of the esophagus with age in this period of development.


2017 ◽  
Vol 11 (03) ◽  
pp. 335-339 ◽  
Author(s):  
Abdurrazaq Olanrewaju Taiwo ◽  
Adebayo Aremu Ibikunle ◽  
Ramat Oyebunmi Braimah ◽  
Omotayo Amidu Sulaiman ◽  
Olalekan Micah Gbotolorun

ABSTRACT Objective: Tooth extraction is a commonly performed procedure in dental clinics. It has been shown that the reasons for and pattern of tooth extraction vary across geographical regions. Few reports on the pattern of extraction among a semi-urban populace exist. To the best of our knowledge, there is no study on the pattern and reasons for tooth mortality from Sokoto, Northwestern Nigeria, which is a semi-urban region. Materials and Methods: A review of the records of patients that had tooth extraction at our center between January 2009 and January 2016, was done. Data such as the age, gender, type of tooth extracted, and reasons for extraction were retrieved and analyzed. Cross tabulations for age and gender were also made. The level of statistical significance was set at P < 0.05. Results: A total of 1167 extractions were performed in 984 patients. An age range of 18–107 years with a mean (±standard deviation) of 34.8 (13.3) was observed. Most of the patients were in the 21–30 years age group accounting for 35.7% of cases. Dental caries and its sequelae (DCS) (631, 54.1%) were the most common reasons for extraction, followed by periodontal disease (192, 16.5%). The difference in proportions of reasons for tooth extraction between the gender was statistically significant (P = 0.02; df = 24). The difference in the reasons for extraction among the age groups was statistically significant (P < 0.001; df = 132). Conclusion: DCS along with periodontal disease were the major reasons for extractions. These are largely preventable causes of tooth extraction; therefore, there is a need for commencement of far-reaching preventative actions.


2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Karen P. Y. Liu ◽  
Monica Lai ◽  
Shirley S. M. Fong ◽  
Michelle Bissett

This study examined if imagery ability (i.e., vividness and temporal congruence between imagined and executed knee extensions) and imagery perspective preference were affected by ageing and gender. Ninety-four participants, 31 young, 43 intermediate, and 20 older adults completed the Vividness of Movement Imagery Questionnaire-2 and a knee extension temporal congruence test to reflect on their imagery ability and an imagery perspective preference test. Male participants had a better imagery ability than the female participants (F 4,85=2.84, p=.029, η2=.118). However, significant age-related changes in imagery ability were not found in the three age groups. Change in imagery perspective preference with a trend towards an external imagery perspective was observed with ageing (F 3,89=3.16, p=.028, η2=.096) but not between male and female. The results suggest that imagery ability may be preserved with ageing. As individuals age, their preference for using an imagery perspective shifts from a more internal to a more external perspective. This understanding is important when designing future imagery research and real-life application or clinical intervention.


2016 ◽  
Vol 37 (12) ◽  
pp. 1517-1539 ◽  
Author(s):  
Jaclyn M. White Hughto ◽  
Sari L. Reisner

This study investigates the relationship between discrimination and mental health in aging transgender adults. Survey responses from 61 transgender adults above 50 ( Mage = 57.7, SD = 5.8; 77.1% male-to-female; 78.7% White non-Hispanic) were analyzed. Multivariable logistic regression models examined the relationship between gender- and age-related discrimination, number of everyday discrimination experiences, and past-week depressive distress, adjusting for social support, sociodemographics, and other forms of discrimination. The most commonly attributed reasons for experiencing discrimination were related to gender (80.3%) and age (34.4%). More than half of participants (55.5%) met criteria for past-week depressive distress. In an adjusted multivariable model, gender-related discrimination and a greater number of everyday discrimination experiences were associated with increased odds of past-week depressive distress. Additional research is needed to understand the effects of aging and gender identity on depressive symptoms and develop interventions to safeguard the mental health of this vulnerable aging population.


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