Deiodinase-mediated thyroid hormone inactivation minimizes thyroid hormone signaling in the early development of fetal skeleton

Thyroid hormone (TH) plays a key role on post-natal bone development and metabolism, while its relevance during fetal bone development is uncertain. To Study this, pregnant once were made hypothyroid and fetuses harvested at embryonic days (E) 12.5, 14.5, 16.5 and 18.5. Despite a marked reduction in fetal tissue concentration of both T4 and T3, bone development, as assessed at the distal epiphyseal growth plate of the femur and vertebra, was largely preserved Lip to E16.5. Only at E18.5, the hypothyroid fetuses exhibited a reduction in femoral type I and type X collagen and osteocalcin mRNA levels, in the length and area of the proliferative and hypertrophic zones, in the number of chondrocytes per proliferative column, and in the number of hypertrophic chondrocyres, in addition to a slight delay in endochondral and intramembranous ossification. This Suggests that LIP to E 16.5, thyroid hormone signaling in bone is kept to a minimum. In fact, measuring the expression level of the activating and inactivating iodothyronine deiodinases (D2 and D3) helped understand how this is achieved. D3 mRNA was readily detected as early as E14.5 and its expression decreased markedly (similar to 10-fold) at E18.5, and even more at 14 days after birth (P14). In contrast. D2 mRNA expression increased significantly by E18.5 and markedly (similar to 2.5-fold) by P14. The reciprocal expression levels of D2 and D3 genes during early bone development along with the absence of a hypothyroidism-induced bone phenotype at this time Suggest that coordinated reciprocal deiodinase expression keeps thyroid hormone signaling in bone to very low levels at this early stage of bone development. (c) 2008 Elsevier Inc. All rights reserved.

If the price is right : vagueness and values clarification in contingent valuation

The use of willingness to pay to value the benefits of health care is increasing. Much of this work assumes that health preferences are well formed or complete and readily revealed if the right question is asked in the right way. We examined this assumption, seeking evidence in a mixed-methods study that explored the meaning and implications of vague responses to a payment-scale based willingness to pay exercise.

One-half of the sample said that their vagueness meant that their maximum willingness to pay was actually greater than the amount that they had previously said it was. Thirty percent agreed that they would probably pay £10 more than a sum that they had previously said they would most definitely not pay, if they found this to be the cost of the vaccine. Interview data supported the view that the payment scale had failed to elicit the maximum willingness to pay and that some participants used the information on cost to help clarify their values, in contrast to the theory underpinning willingness to pay. The results suggest a need to consider values-clarification in health economic evaluations. Copyright © 2002 John Wiley & Sons, Ltd.

'Skeleton budget', 'intranet', 'dole', and other strange Words: Bridging the cultural divide in a multicultural classroom

This paper examines the experiences of two academics who had been international students themselves and currently teaching in multicultural settings at tertiary level, with regards to the issues of the teacher using culture specific slang and idiom with otherwise keen and bright groups of students, in Australia. Using the research method of auto-ethnography, it examines and categorises the themes of issues most often faced by the staff members and students-such as the use of different vocabulary and keywords and the prior knowledge required of both the teacher and the students in reaching a shared understanding or inter-subjectivity. These will be discussed in terms of the various realities experienced by the students coming from a diversity of countries and cultures. The paper discusses how these challenges can be identified and addressed and how to prepare for future situations more effectively and in advance. They will be examined within the contexts of culturally responsive teaching, communication competence, the hidden curriculum, instructional scaffolding, understanding and being open to other cultures and acknowledgement of the richness and relevance of the multicultural students’ varied experiences and social realities, from the point of view of the academic discipline of communication studies.

A clarification of the ERI model : the importance of personality

The present study aimed to investigate the role of personality in the etfort-reward imbalance model along with the construct validity of overcommitment in relation to Type A behaviour. The study sample consisted of 898 operational law enforcement persolllel from a large Australian police service. Factor analysis revealed that the overcommitment construct was psychologically related to, but distinct from, the Type A dimensions achievement striving, impatience-irritability and hostility despite the hypothesised interrelatedness of the measures. Multiple regression analyses including tests for curvilinear effects revealed that the Type A dimensions made a significant improvement to the prediction of employee wellbeing and job satisfaction, The results of the study provide theoretical implications in terms of the augmentation of the effort-reward imbalance model.

History of amenorrhoea compromises some of the exercise-induced benefits in cortical and trabecular bone in the peripheral and axial skeleton : a study in retired elite gymnasts

Background : Female gymnasts frequently present with overt signs of hypoestrogenism, such as late menarche or menstrual dysfunction. The objective was to investigate the impact of history of amenorrhoea on the exercise-induced skeletal benefits in bone geometry and volumetric density in retired elite gymnasts.
Subjects and methods

24 retired artistic gymnasts, aged 17–36 years, who had been training for at least 15 h/week at the peak of their career and had been retired for 3–18 years were recruited. They had not been engaged in more than 2 h/week of regular physical activity since retirement. Former gymnasts who reported history of amenorrhoea (‘AME’, n = 12: either primary or secondary amenorrhoea) were compared with former gymnasts (‘NO-AME’, n = 12) and controls (‘C’, n = 26) who did not report history of amenorrhoea. Bone mineral content (BMC), total bone area (ToA) and total volumetric density (ToD) were measured by pQCT at the radius and tibia (4% and 66%). Trabecular volumetric density (TrD) and bone strength index (BSI) were measured at the 4% sites. Cortical area (CoA), cortical thickness (CoTh), medullary area (MedA), cortical volumetric density (CoD), stress–strain index (SSI) and muscle and fat area were measured at the 66% sites. Spinal BMC, areal BMD and bone mineral apparent density (BMAD) were measured by DXA.
Results

Menarcheal age was delayed in AME when compared to NO-AME (16.4 ± 0.5 years vs. 13.3 ± 0.4 years, p < 0.001). No differences were detected between AME and C for height-adjusted spinal BMC, aBMD and BMAD, TrD and BSI at the distal radius and tibia, CoA at the proximal radius, whereas these parameters were greater in NO-AME than C (p < 0.05–0.005). AME had lower TrD and BSI at the distal radius, and lower spinal BMAD than NO-AME (p < 0.05) but they had greater ToA at the distal radius (p < 0.05).
Conclusion

Greater spinal BMC, aBMD and BMAD as well as trabecular volumetric density and bone strength in the peripheral skeleton were found in former gymnasts without a history of menstrual dysfunction but not in those who reported either primary or secondary amenorrhoea. History of amenorrhoea may have compromised some of the skeletal benefits associated with high-impact gymnastics training.

Improved 3D thinning algorithms for skeleton extraction

In this study, we focused on developing a novel 3D Thinning algorithm to extract one-voxel wide skeleton from various 3D objects aiming at preserving the topological information. The 3D Thinning algorithm was testified on computer-generated and real 3D reconstructed image sets acquired from TEMT and compared with other existing 3D Thinning algorithms. It is found that the algorithm has conserved medial axes and simultaneously topologies very well, demonstrating many advantages over the existing technologies. They are versatile, rigorous, efficient and rotation invariant.