The muscle-bone unit in adolescent swimmers.

Most researchers adjust bone by lean mass when comparing swimmers with controls. This adjustment is done under the assumption that lean affects bone similarly in both groups. Nonetheless, we found that the muscle-bone association is uncoupled in swimmers, and consequently, researchers should avoid this adjustment when evaluating swimmers' bone. INTRODUCTION: To examine the functional and structural muscle-bone unit in adolescent swimmers. METHODS: Sixty-five swimmers (34 girls/31 boys) and 119 controls (51 girls/68 boys) participated in the study. Muscle cross-sectional area (MCSA), bone mineral content (BMC), and polar strength-strain index (SSIPOL) were measured in the non-dominant radius by peripheral quantitative computed tomography (pQCT). Subtotal BMC and lean mass were evaluated with dual-energy X-ray absorptiometry (DXA). Handgrip and isometric knee extension (IKE) tests were performed to determine muscle force. The effect of MCSA, lean and force on SSIPOL, and BMC were tested, and the functional and structural muscle-bone ratios of swimmers and controls were compared. RESULTS: Both muscle size (MCSA and lean) and muscle force (handgrip and IKE) influenced BMC and SSIPOL in swimmers and controls similarly. Swimmers presented normal MCSA and lean values for their height, but when compared with controls, swimmers presented a higher amount of lean and MCSA for the same BMC or SSIPOL (structural muscle-bone unit). For the functional muscle-bone unit, different results were found for the lower and upper limbs, as no differences were found for the upper limbs, while for the lower limbs, swimmers presented higher muscle force for the same amount of BMC. CONCLUSIONS: The contradictory results regarding BMC in swimmers found in previous studies could partly be explained with the findings of the present study that reinforce the idea that swimming is not an effective sport to practice regarding bone mass and that the muscle-bone unit is different in swimmers than in controls.

Does fitness attenuate the relationship between changes in sitting time and health-related quality of life over time in community-dwelling older adults? Evidence from the EXERNET multicenter longitudinal study.

OBJECTIVE: To assess the relationship between fitness levels and components, sitting time and health-related quality of life (HRQoL), over time among community-dwelling older adults. METHODS: Three different sitting trajectories were calculated: (i) no change; (ii) decrease; and (iii) increase in ST, between baseline and follow-up. Fitness was assessed using the aerobic capacity, upper and lower limb strength, and total fitness. Participants were classified into higher (75th percentile or above) or lower (below 75th percentile) fitness levels, using the fitness tests. HRQoL scores at follow-up were compared to the three different sitting time trajectories within and across both the higher and the lower fitness groups for each of the three fitness indexes. RESULTS: Greater HRQoL scores were observed in those participants that decreased their ST as compared with those increasing their sitting time over time for participants classified in the lower end of their aerobic capacity or total fitness index. No differences were detected in HRQoL scores in people classified in the higher fitness level group for any of the fitness indexes. Participants that increased or did not change their sitting time and who were classified in the higher fitness end of aerobic capacity and total fitness index self-reported higher HRQoL scores when compared with those in the lower fitness end. CONCLUSION: Increased sitting time over time is associated with poorer HRQoL in older adults. Higher fitness levels could help attenuate the negative impact of sitting over time.

Effect of whole-body vibration training on bone mass in adolescents with and without Down syndrome: a randomized controlled trial.

UNLABELLED: Whole-body vibration training (WBV) attracts great interest as osteoporosis prevention strategy. Twenty-six adolescents with and without Down syndrome (DS) (13 DS; 12-18 years) performed 20 weeks of WBV. The results indicate that WBV seems to provoke a lesser response in adolescents with DS than in those without DS. INTRODUCTION: This study aims to observe the differences between adolescents with and without DS in the effects of 20 weeks of WBV training, on bone mineral content (BMC) and density (BMD). METHODS: Twenty-six adolescents (13 DS; 12-18 years) were measured with dual-energy X-ray absorptiometry before and after the intervention (3/week, 10 repetitions (30-60 s) and 1-min rest, frequency 25-30 Hz and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)). Both, an intention-to-treat (ITT) analysis designed to assess the effects on bone mass and a per-protocol analysis, designed to compare poor and high compliers, were performed. RESULTS: The ITT analysis revealed significant increases in all BMC and BMD parameters (dz = 0.66 to 1.64; all p < 0.05) in the non-DS group, whilst DS group improved whole-body, subtotal (whole-body less head), upper limbs (ULIMBS), pelvis, lower limbs (LLIMBS) and spine BMC (dz = 0.75 to 1.76; all p < 0.05) and subtotal, pelvis, LLIMBS and spine BMD (dz = 0.73 to 1.28; all p < 0.05). Significantly greater increases were evident in the absolute and percent changes of the non-DS group over DS group (d = 0.88 to 3.85; all p < 0.05). ULIMBS BMD showed a tendency towards an interaction (f = 0.41 and p = 0.086) with higher increase for non-DS group. When a per-protocol analysis was considered, high-complier adolescents had 8.1 versus 5.3 % of gains in the spine BMC over poor-complier adolescents (d = 0.93; p < 0.05). CONCLUSIONS: Twenty weeks of WBV training may improve BMC and BMD in clinically relevant skeletal sites in both groups. Nevertheless, this type of training seems to provoke a lesser response in adolescents with DS than in those without DS.

Swimming and bone: Is low bone mass due to hypogravity alone or does other physical activity influence it?

UNLABELLED: Swimming during adolescence has shown neutral or even negative effects on bone mass. Nevertheless, it is still unknown if these effects are due to swimming or to other factors, such as sedentary behaviors. INTRODUCTION: Three objectives were described (1) to measure objective physical activity (PA) additional to swimming performed by adolescent swimmers (SWI) and compare it to that performed by normo-active controls (CG), (2) to describe the relationship between objectively measured PA and bone mass, and (3) to compare bone mass of swimmers that meet the World Health Organization PA guidelines (active) WHO and those that do not (inactive). METHODS: A total of 71 SWI (33 females) and 41 CG (17 females) wore an accelerometer for at least 4 days. PA was expressed as the amount of time (minutes/day) in each intensity [sedentary/light/moderate or vigorous (VPA), and the sum of moderate and vigorous (MVPA)]. Using the cutoff points proposed by Vanhelst et al. SWI were classified as active or inactive according to whether they reached 60 min of weight-bearing MVPA per day or not. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry, and bone strength values were calculated with peripheral quantitative computed tomography. Differences in PA intensities were calculated between SWI and CG. The relation of VPA to bone mass was studied in the SWI. RESULTS: Male-SWI spend less time in VPA and MVPA than male-GC, which partly explains the lower BMD values in SWI than CG. CONCLUSION: Swimming may displace weight-bearing VPA with serious implications on bone health.

Effect of whole body vibration training on bone mineral density and bone quality in adolescents with Down syndrome: a randomized controlled trial.

UNLABELLED: Adolescents with Down syndrome (DS) have poorer bone health than their peers without DS. Twenty-five adolescents with DS were randomly assigned to whole-body vibration training (WBV) or control groups. The results indicate that a 20-week WBV might be useful to improve subtotal bone mineral content and density in adolescents with DS. INTRODUCTION: This study aims to determine the effects of 20 weeks of whole body vibration training (WBV) on bone mineral content (BMC), density (BMD), and structure variables in adolescents with Down syndrome (DS). METHODS: This randomized controlled trial of 25 adolescents (12-18 years) with DS (8 females) generated 2 non-equal groups, WBV group (n = 11) and CON group (n = 14). Using an efficacy analysis, the primary outcomes were BMC and BMD by dual-energy X-ray absorptiometry and the secondary were bone structure variables by peripheral quantitative computed tomography. A synchronous vibration platform (PowerPlate®) was used (3/week, 10 repetitions (30-60 s) 1-min rest, frequency of 25-30 Hz, and peak-to-peak displacement of 2 mm (peak acceleration 2.5-3.6 g)). RESULTS: WBV group improved whole body BMC 2.8%, 95% CI [3.5, 2.1], subtotal area, BMC, and BMD by 2.8, 4.8, and 2%, respectively, 95% confidence intervals (CIs) [3.4, 2.1], [6.5, 3.1], and [2.8, 1.1], respectively (all, p < 0.05), showing group by time interactions in BMC and BMD (both p < 0.05). Lumbar spine BMC and BMD also increased in the WBV group by 6.6 and 3.3% both p < 0.05, 95 % CIs [8.6, 4.7], and [4.9, 1.7], respectively. Regarding bone structure, WBV group showed improvements in tibial BMC at 4 % (2.9 %, 95 % CI [3.0, 2.8]) and in volumetric BMD (vBMD), cortical vBMD, and cortical thickness at 66% of the radius (by 7.0, 2.4, and 10.9%; 95% CIs [7.4, 6.7], [2.6, 2.3], and [12.4, 9.3], respectively) (all, p < 0.05). CONCLUSIONS: A 20-week WBV, with this protocol, might be useful to improve subtotal BMC and BMD in adolescents with DS.

The effects of swimming training on bone tissue in adolescence.

The aim was to analyze bone mineral content (BMC) and density (BMD) in regular swimming trained adolescents and the interaction that weigh-bearing sports may have on these values. Bone mass was evaluated by dual energy x-ray absorptiometry (DXA) and quantitative ultrasound (QUS) in 77 swimmers (34 females/43 males) and 52 normoactive controls (CG; 23 females/29 males) from 11 to 18 years. Swimmers who had performed or were performing other sports (OSP; 11 females/20 males) were compared with pure swimmers (PSW; 23 females/23 males). Both groups were compared with CG. Bone values were compared using analyses of covariance adjusting for height, calcium intake, subtotal lean (whole body lean minus head), and pubertal status. Male PSW showed lower BMD and BMC at several sites than male CG. However, for male OSP, only lumbar spine BMC was lower in OSP than male CG. Male PSW showed lower BMD and BMC when compared with male OSP. Female PSW showed higher arm BMD and lower leg BMC than female CG, while female OSP only presented lower leg BMC than female CG. Contrary to males, female-PSW presented higher BMD and BMC than female OSP. No differences in QUS values were found between swimmers and CG. To summarize, although more information is needed for females, it seems that for males, swimming is associated with lower BMC and BMD.

Body Composition Evolution in Elite Football Referees; an Eleven-years Retrospective Study.

Fitness, and specifically body composition of football referees requires attention in order to achieve the highest possible standards. The aim of the present study was to describe body composition of elite Spanish football referees over 11 years. Data from 2001 to 2012 pre-seasons were analyzed from a total of 470 referees of 1(st) and 2(nd) categories in Spanish male football (1C and 2C respectively). Body mass index (BMI), sum of 6 skinfolds (6SS) and percentage of body fat (%BF) were assessed. 2-independent samples Student's t-test between categories, and ANOVA tests with Bonferroni post-hoc analyses among seasons were applied. Overall, 1C referees were older than 2C in every season, and both 1C and 2C showed a decrease in 6SS, BMI and %BF throughout seasons (all p<0.05; from 82.5 to 62.9 mm, from 23.7 to 22.4 kg/m(2) and from 13.7 to 11.7%). No differences were observed between categories in any season. Since football referees at the highest levels need to have a low %BF for the intense matches nowadays, an improvement in their body composition profile has been observed in a highly competitive league as 'La Liga' in Spain over the last decade.

Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome: a peripheral quantitative computed tomography (pQCT) study.

UNLABELLED: We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes. INTRODUCTION: The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities. METHODS: Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups. RESULTS: The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group. CONCLUSIONS: From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion.

In vitro embryo production in llamas (Lama glama) from in vivo matured oocytes with raw semen processed with Androcoll-E using defined embryo culture media.

The aim of this study was to carry out in vitro fertilization using spermatozoa selected with Androcoll-E™ and to evaluate the efficiency of the culture medium DMEM-F12 for in vitro embryo development in the llama. Twelve adult females from 18 superstimulated (67%) were used as oocyte donors. They were superstimulated with 1500 IU of eCG and after 5 days, received a single dose of buserelin. Twenty hours post-injection, follicular aspiration was conducted by flank laparotomy. Semen collections were performed under general anesthesia by electroejaculation of the male. The ejaculates were processed with a solution of collagenase (0.1%) and an Androcoll-E™ column was used to improve the sample. Sixty nine COCs were recovered from 79 aspirated follicles (87% recovery). Only expanded COCs were used (n = 67); they were randomly placed in groups of 1-5 in Fertil-TALP and the sperm suspension (20 × 10(6) live spermatozoa/ml) was added to each fertilization microdroplet. After 24 h, they were randomly placed in one of two culture media: SOF (n = 34) or DMEM-F12 (n = 33) and incubated for 6 days in humidified atmosphere of 5% CO(2) , 5% O(2) and 90% N(2) at 38°C. The blastocyst rate was 20% (7/34) in SOF medium (3 hatched, 2 expanded and 2 early blastocysts) and 15% (5/33) in DMEM medium (all expanded blastocysts). In conclusion, using Androcoll-E™ it is possible to select good quality spermatozoa from llama ejaculates for in vitro fertilization and to produce blastocysts in DMEM-F12 medium. This is also the first time that hatched llama blastocysts have been produced after culture in a defined medium such as SOFaa.

Impact of methodological decisions on accelerometer outcome variables in young children.

BACKGROUND: The impact of accelerometer-related methodological decisions relating to the assessment of physical activity and sedentary time has not been conclusively determined in young children. OBJECTIVES: To determine the effects of epoch and cutoff points on the assessment of physical activity and sedentary time and to determine the accelerometer wear time required to achieve reliable accelerometer data in children. DESIGN: Children were recruited from centres at Ghent, Glasgow, Gothenburg and Zaragoza. METHODS: Physical activity was assessed for 1 week in 86 children (41 girls, 45 boys; mean age 7±2 years) by uniaxial accelerometry. The epoch was set at 15 s and reintegrated to 30 and 60 s. Time spent sedentary and in moderate and vigorous physical activity (MVPA) was assessed using a range of cutoff points. Number of days required to achieve 80% reliability was predicted using the Spearman-Brown Prophecy formula. RESULTS: The Reilly cutoff points (<1100 counts per min (CPM)) indicated less sedentary time per day when comparing 15 vs 30 s and 15 vs 60 s epochs: 570±91 vs 579±93 min and 570±91 vs 579±94 min, respectively; P<0.05. Pate cutoff points (>420 counts per 15 s) reported more MVPA time per day compared with Sirard (890 counts per 15 s) and Puyau cutoff points (>3200 counts per min) using 15 s epoch: 78 (4-197) min (median (range) vs 18 (1-80) min and 24 (1-100) min, respectively; P<0.001. Compliance with guidelines of at least 60 min MVPA was 84, 78 and 73% for Pate cutoff points using 15, 30 and 60 s epochs, respectively, but 0% for Sirard and Puyau cutoff points across epochs. The number of days required to achieve 80% reliability for CPM, sedentary and MVPA time was 7.4-8.5 days. CONCLUSION: Choice of epoch and cutoff point significantly influenced the classification of sedentary and MVPA time and observed compliance to the MVPA guidelines.

Bone mass in male and female children and adolescents with Down syndrome.

SUMMARY: Children and adolescents with Down syndrome (DS) have lower levels of bone mass compared with youths without DS. Their sexual dimorphism in bone mass also differs from that observed in children and adolescents without Down syndrome. INTRODUCTION: This study aimed to compare bone mass and sexual dimorphism in bone mass between male and female youths with DS and age- and sex-matched controls without DS. METHODS: Bone mineral density (BMD), volumetric BMD, bone mineral apparent density (BMAD), BMD/height (BMDH), and total lean mass were measured or calculated from DXA. Thirty-two youths (15 females) with DS and 32 youths (13 females) without DS participated in the study. RESULTS: ANOVA tests showed lower BMAD and BMDH in females with DS compared with females without DS. ANCOVA tests revealed lower BMD in the whole body of males and females as well as BMD in the hip region of the females with DS compared with their counterparts without DS. Within the group with DS, females had greater lumbar spine BMD than the males. CONCLUSIONS: The low values of BMD and related parameters, together with the differences in the sexual dimorphism, indicate a non-standard bone development in this specific population of children and adolescents with DS.

Health-related physical fitness in children and adolescents with Down syndrome and response to training.

Physical fitness is related to health at all ages. Information about physical fitness in the Down syndrome (DS) population, however, is scarce, especially when we consider children and adolescents. A review of the current data available on this topic would be both timely and important as it would serve as a starting point to stimulate new research perspectives. The data we reviewed from the literature showed a general trend toward lower values of physical fitness parameters and worse body composition variables in children and adolescents with DS compared with the population without intellectual disability (ID) or even with the population with ID without DS. Notably, children and adolescents with DS have been described as less active or overprotected; however, these factors may not be the cause of their poor physical fitness. Many of the training programs carried out in children and adolescents with DS did not yield the desired responses, and the reasons are still unknown. The purpose of this review is to summarize the current available literature on health-related physical fitness in children and adolescents with DS, and the effect of training on these variables. From the literature available, it is clear that more data on this population are necessary.

Associations between Physical Fitness, Bone Mass, and Structure in Older People.

The main aim was to analyse the associations between several physical fitness variables and bone parameters in a sample of elderly people. 129 participants (94 females and 35 males, 76.2 ± 5.4 y) from the EXERNET cohort of Zaragoza (Spain) were included in the study. Physical fitness was assessed using the Senior Fitness Test Battery. Peripheral quantitative computed tomography (pQCT) at the tibia and dual-energy X-ray absorptiometry (DXA) at the hip and lumbar spine were used to assess bone and muscle parameters. Partial correlations were used to describe the associations between fitness and bone parameters. A stepwise regression analysis was used to determine the influence of fitness variables on bone parameters. In males, significant correlations were found between lower body strength and agility with bone total mineral density (Tt.BMD) (r = 0.41 and -0.50) and cortical thickness (r = 0.40 and -0.50, respectively) and walking speed with total and cortical density (r = -0.41 and -0.40, respectively), all measured at tibia (all p < 0.05). Regarding DXA, neck areal bone mineral density (aBMD) correlated with flexibility (r = -0.37) and walking speed (r = 0.39) and Ward's triangle with walking speed (r = 0.39). Agility predicted Tt.BMD and cortical thickness (r 2 change = 24.8% and 23.0%), while walking speed predicted cortical bone mineral density (r 2 change = 19.5%) (all p < 0.05). Females showed correlations between balance and total hip aBMD (r = 0.27) and trochanter aBMD (r = 0.25). Balance predicted trochanter (r 2 change = 4.2%) and total hip aBMD (r 2 change = 4.9%) (both p < 0.05). In conclusion, bone mass in elderly males seems to be more influenced by physical fitness than in females, being agility and walking speed the variables showing greater associations. Other variables should be taken into account in females for future research.

Effect of eCG superstimulation and buserelin on cumulus-oocyte complexes recovery and maturation in llamas (Lama glama).

The aim of the present study was two-fold. Experiment I: evaluate the effect of buserelin on llama's oocyte maturation after exogenous follicular activity suppression, followed by ovarian superstimulation with different doses of equine chorionic gonadotropin (eCG). Experiment II: compare the number of follicles aspirated and the number of cumulus-oocyte complexes (COCs) recovered according to different doses of eCG followed by buserelin. Experiment I consisted in a control group (without buserelin) and a treatment group (with buserelin), both subdivided according to eCG dose administered: A: 500 IU; B: 1000 IU; C: 1500 IU. The treatment group received a single i.v. dose of 8 microg of buserelin when two or more dominant follicles were found at ultrasound evaluation and 20 h later were subjected to surgery. In group A, 83% of the llamas did not respond to superstimulation. In groups B and C differences were observed between the control and the treatment groups for the degree of COCs maturation (p < 0.05). In experiment II animals were divided into two groups according to the eCG dose administered: 1000 and 1500 IU. Twenty hours before surgery females received a single i.v. dose of 8 microg of buserelin. Average number of follicles aspirated and COCs recovered was higher (p < 0.05) with the administration of 1500 IU of eCG. A larger number of expanded COCs were obtained from follicles > or =7 mm in diameter. We conclude that buserelin aids the recovery of a larger number of expanded COCs. Administration of 1500 IU of eCG produces a higher number of follicles for aspiration and number of COCs recovered.

Outcome of drug-induced sleep endoscopy-directed surgery for persistent obstructive sleep apnea after adenotonsillar surgery.

PURPOSE: Drug-induced sleep endoscopy (DISE) is suitable for evaluating persistent obstructive sleep apnea syndrome (OSAS) after adenotonsillar surgery as a means to guide surgical intervention, yet few studies demonstrate its usefulness in resolving the syndrome. We describe our experience of DISE-directed surgery in children with persistent OSAS by analysing objective and subjective outcomes of this treatment. METHODS: Prospective study of 20 otherwise healthy 2-12 year-old children with OSAS persisting after adenotonsillar surgery. All patients underwent DISE-directed surgery and were followed up clinically and with a polysomnogram at 12 ±â€¯3 months. RESULTS: All 20 children had an apnea-hypopnea index (AHI) score ≥1 (mean: 6.1 ±â€¯4.9) and 75% had AHI>3 before surgery. We performed a total of 14 total tonsillectomies (70%), 7 with associated pharyngoplasties; 5 radiofrequency turbinate reductions (25%); 7 radiofrequency lingual tonsil reductions (35%); and 10 revision adenoidectomies (50%). No surgery-related complications were observed. AHI scores at follow-up were significantly lower than AHI scores before surgery (1.895 ±â€¯1.11 vs 6.143 ±â€¯4.88; p < 0.05) and, in 85% (n = 17) of patients, AHI was below 3. There was a significant reduction in the number of children with AHI>3 in follow-up at 12 ±â€¯3 months (15%; n = 3) compared to before surgery (75%; n = 15) (p < 0.005). CONCLUSION: DISE-directed surgery for otherwise healthy children with persistent OSAS is a useful and safe technique to decide a therapeutic strategy and to obtain good objective and subjective results regarding resolution of the syndrome.

Application of the Spanish methodological approach for biosphere assessment to a generic high-level waste disposal site.

A methodological approach which includes conceptual developments, methodological aspects and software tools have been developed in the Spanish context, based on the BIOMASS "Reference Biospheres Methodology". The biosphere assessments have to be undertaken with the aim of demonstrating compliance with principles and regulations established to limit the possible radiological impact of radioactive waste disposals on human health and on the environment, and to ensure that future generations will not be exposed to higher radiation levels than those that would be acceptable today. The biosphere in the context of high-level waste disposal is defined as the collection of various radionuclide transfer pathways that may result in releases into the surface environment, transport within and between the biosphere receptors, exposure of humans and biota, and the doses/risks associated with such exposures. The assessments need to take into account the complexity of the biosphere, the nature of the radionuclides released and the long timescales considered. It is also necessary to make assumptions related to the habits and lifestyle of the exposed population, human activities in the long term and possible modifications of the biosphere. A summary on the Spanish methodological approach for biosphere assessment are presented here as well as its application in a Spanish generic case study. A reference scenario has been developed based on current conditions at a site located in Central-West Spain, to indicate the potential impact to the actual population. In addition, environmental change has been considered qualitatively through the use of interaction matrices and transition diagrams. Unit source terms of (36)Cl, (79)Se, (99)Tc, (129)I, (135)Cs, (226)Ra, (231)Pa, (238)U, (237)Np and (239)Pu have been taken. Two exposure groups of infants and adults have been chosen for dose calculations. Results are presented and their robustness is evaluated through the use of uncertainty and sensitivity analyses.

Addressing uncertainties in the ERICA Integrated Approach.

Like any complex environmental problem, ecological risk assessment of the impacts of ionising radiation is confounded by uncertainty. At all stages, from problem formulation through to risk characterisation, the assessment is dependent on models, scenarios, assumptions and extrapolations. These include technical uncertainties related to the data used, conceptual uncertainties associated with models and scenarios, as well as social uncertainties such as economic impacts, the interpretation of legislation, and the acceptability of the assessment results to stakeholders. The ERICA Integrated Approach has been developed to allow an assessment of the risks of ionising radiation, and includes a number of methods that are intended to make the uncertainties and assumptions inherent in the assessment more transparent to users and stakeholders. Throughout its development, ERICA has recommended that assessors deal openly with the deeper dimensions of uncertainty and acknowledge that uncertainty is intrinsic to complex systems. Since the tool is based on a tiered approach, the approaches to dealing with uncertainty vary between the tiers, ranging from a simple, but highly conservative screening to a full probabilistic risk assessment including sensitivity analysis. This paper gives on overview of types of uncertainty that are manifest in ecological risk assessment and the ERICA Integrated Approach to dealing with some of these uncertainties.

Issues and practices in the use of effects data from FREDERICA in the ERICA Integrated Approach.

The ERICA Integrated Approach requires that a risk assessment screening dose rate is defined for the risk characterisation within Tiers 1 and 2. At Tier 3, no numerical screening dose rate is used, and the risk characterisation is driven by methods that can evaluate the possible effects of ionising radiation on reproduction, mortality and morbidity. Species sensitivity distribution has been used to derive the ERICA risk assessment predicted no-effect dose rate (PNEDR). The method used was based on the mathematical processing of data from FRED (FASSET radiation effects database merged with the EPIC database to form FREDERICA) and resulted in a PNEDR of 10 microGy/h. This rate was assumed to ascribe sufficient protection of all ecosystems from detrimental effects on structure and function under chronic exposure. The value was weighed against a number of points of comparison: (i) PNEDR values obtained by application of the safety factor method, (ii) background levels, (iii) dose rates triggering effects on radioactively contaminated sites and (iv) former guidelines from literature reviews. In Tier 3, the effects analysis must be driven by the problem formulation and is thus highly case specific. Instead of specific recommendations on numeric values, guidance on the sorts of methods that may be applied for refined effect analysis is provided and illustrated.

Obstructive sleep apnea syndrome and growth failure.

Obstructive sleep apnea syndrome is a common problem among children and is recognized as a cause of significant medical morbidity. Since the 1980s, it has been suggested that obstructive sleep apnea syndrome is a risk factor for growth failure in children. In many cases, it has been shown that growth failure is reversible once the obstructive sleep apnea syndrome is resolved. The objectives of this study were to analyze and compare growth failure prevalence in a Mediterranean population of children with obstructive sleep apnea syndrome and healthy children matched in age and sex, and to assess the effectiveness of tonsillectomy and adenoidectomy in resolving growth retardation. We compared 172 children with obstructive sleep apnea syndrome (apnea-hypopnea index ≥ 3) who had undergone tonsillectomy and adenoidectomy with 172 healthy controls in terms of key anthropometric parameters. Most of the criteria used for growth failure were higher to a statistically significant degree in the study group vs the control group: height-for-age ≤ 3rd percentile (7.56% vs 2.91%; p = 0.044), weight-for-age ≤ 5th percentile (9.30% vs 2.33%; p = 0.005), weight-for-age ≤ 3rd percentile (8.14% vs 2.33%; p = 0.013) and height and/or weight for-age ≤ 5th percentile (13.95% vs 5.81%; p = 0.009). The height-for-age ≤ 5th percentile was almost at the limit of statistical significance (8.72% for the study group vs 4.65% for the control group; p = 0.097). At one-year post-surgery follow-up, 10 of 15 children with height-for-age ≤ 5th percentile had achieved catch-up growth (66.6%), and 14 of 24 children with height- and/or weight-for-age ≤ 5th percentile had normalized growth (58.33%). For children with failure to thrive or who have growth failure, physicians should consider the possibility of obstructive sleep apnea. A significant number of children with obstructive sleep apnea concurrent with growth failure could benefit from tonsillectomy and adenoidectomy to recover and normalize their growth rate.

Spanish methodological approach for biosphere assessment of radioactive waste disposal.

The development of radioactive waste disposal facilities requires implementation of measures that will afford protection of human health and the environment over a specific temporal frame that depends on the characteristics of the wastes. The repository design is based on a multi-barrier system: (i) the near-field or engineered barrier, (ii) far-field or geological barrier and (iii) the biosphere system. Here, the focus is on the analysis of this last system, the biosphere. A description is provided of conceptual developments, methodological aspects and software tools used to develop the Biosphere Assessment Methodology in the context of high-level waste (HLW) disposal facilities in Spain. This methodology is based on the BIOMASS "Reference Biospheres Methodology" and provides a logical and systematic approach with supplementary documentation that helps to support the decisions necessary for model development. It follows a five-stage approach, such that a coherent biosphere system description and the corresponding conceptual, mathematical and numerical models can be built. A discussion on the improvements implemented through application of the methodology to case studies in international and national projects is included. Some facets of this methodological approach still require further consideration, principally an enhanced integration of climatology, geography and ecology into models considering evolution of the environment, some aspects of the interface between the geosphere and biosphere, and an accurate quantification of environmental change processes and rates.