129 research outputs found

    Estimation of breast height diameter and trunk curvature with linear and single-photon LiDARs

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    International audienceContext: Precision forestry together with new sensor technologies implies Digital Forest Inventories for estimation of volume and quality of trees in a stand.Aims: This study compared commercial LiDAR, new prototype SPAD LiDAR, and manual methods for measuring tree quality attributes, i.e., diameter at breast height (DBH) and trunk curvature in the forest stand.Methods: We measured 7 Scots pine trees (Pinus sylvestris) with commercial LiDAR (Zeb Horizon by GeoSLAM), prototype SPAD LiDAR, and manual devices. We compared manual measurements to the DBH and curvature values estimated based on LiDAR data. We also scanned a densely branched Picea abies to compare penetrability of the LiDARs and detectability of the obstructed trunk.Results: The DBH values deviated 1–3 cm correlating to the specified accuracies of the employed devices, showing close to acceptable results. The curvature values deviated 1–6 cm implying distorted range measurements from the top part of the trunks and inaccurate manual measurement method, leaving space for improvement. The most important finding was that the SPAD LiDAR outperformed conventional LiDAR in detecting tree stem of the densely branched spruce.Conclusion: These results represent preliminary but clear evidence that LiDAR technologies are already close to acceptable level in DBH measurements, but not yet satisfactory for curvature measurements. In addition, terrestrial SPAD LiDAR has a great potential to outperform conventional LiDARs in forest measurements of densely branched trees

    Pre-pregnancy overweight or obesity and gestational diabetes as predictors of body composition in offspring twenty years later : evidence from two birth cohort studies

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    Background. Global prevalence of overweight/obesity and gestational diabetes (GDM) is increasing. In pregnant women both conditions affect offspring's later health. Overweight/obesity is a risk factor of GDM; to what extent maternal overweight/obesity explains long-term effects of GDM in offspring is unknown. Objective. To evaluate effects of maternal pre-pregnancy overweight/obesity (BMI ⩾25 kg/m2) and GDM, occurring together or separately, on body composition among adult offspring. Methods. Participants include 891 individuals aged 24.1 years (s.d. 1.4) from two longitudinal cohort studies (ESTER and AYLS). Adult offspring of normoglycemic mothers with overweight/obesity (ONOO, n=153), offspring of mothers with GDM (OGDM; n=191) and controls (n=547) underwent anthropometric measurements and bioimpedance analysis. GDM was diagnosed by oral glucose tolerance test. Data were analyzed by linear regression models adjusted for confounders. Results. Compared with controls, ONOO-participants showed higher BMI [men 1.64 kg/m2 (95% confidence interval 0.57, 2.72); women 1.41 kg/m2 (0.20, 2.63)] and fat percentage [men 2.70% (0.99, 4.41); women 2.98% (0.87, 5.09)] with larger waist circumferences [men 3.34 cm (0.68, 5.99); women 3.09 cm (0.35, 5.83)]. Likewise, OGDM-participants showed higher fat percentage [men 1.97% (0.32, 3.61); women 2.32% (0.24, 4.41)]. BMI was non-significantly different between OGDM-participants and controls [men 0.88kg/m2 (-0.17, 1.92); women 0.82 kg/m2 (-0.39, 2.04)]. Also waist circumferences were larger [men 2.63 cm (-0.01, 5.28); women 3.39 cm (0.60, 6.18)], this difference was statistically significant in OGDM-women only. Differences in body composition measures were stronger among offspring of women with both GDM and overweight/obesity. For instance, fat mass was higher among OGDM-participants of overweight mothers [men 4.24 kg (1.36, 7.11) vs controls; women 5.22 kg (1.33, 9.11)] than OGDM participants of normal weight mothers [men 1.50 kg (-2.11, 5.11) higher vs controls; women 1.57 kg (-3.27, 6.42)]. Conclusions. Maternal pre-pregnancy overweight and GDM are associated with unhealthy body size and composition in offspring over 20 years later. Effects of maternal pre-pregnancy overweight appear more pronounced

    Milk and milk-derived peptides combat against hypertension and vascular dysfunction : a review

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    Epidemiological studies have revealed that consumption of milk and fermented dairy products is inversely associated with elevated blood pressure and with many of the risk factors of the metabolic syndrome. Previously, calcium was thought to be behind this phenomenon, but during the last 20 years, convincing evidence emerging from experimental, epidemiological and intervention studies has highlighted the important role of the small peptides formed during fermentation processes. This review provides an overview of the potential blood pressure lowering components present in dairy products with a special focus on casein-derived tripeptides.Peer reviewe

    Postexercise Heart Rate Recovery in Adults Born Preterm

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    Objective To evaluate postexercise heart rate recovery (HRR) in adults born preterm. Study design We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm ( Results Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group. Conclusions Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.Peer reviewe

    Lung function in adults born preterm

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    Very preterm birth, before the gestational age (GA) of 32 weeks, increases the risk of obstructed airflow in adulthood. We examined whether all preterm births (GA<37 weeks) are associated with poorer adult lung function and whether any associations are explained by maternal, early life/neonatal, or current life factors. Participants of the ESTER Preterm Birth Study, born between 1985 and 1989 (during the pre-surfactant era), at the age of 23 years participated in a clinical study in which they performed spirometry and provided detailed medical history. Of the participants, 139 were born early preterm (GA<34 weeks), 239 late preterm (GA: 34-<37 weeks), and 341 full-term (GA≥37 weeks). Preterm birth was associated with poorer lung function. Mean differences between individuals born early preterm versus full-term were -0.23 standard deviation (SD) (95% confidence interval (CI): -0.40, -0.05)) for forced vital capacity z-score (zFVC), -0.44 SD (95% CI -0.64, -0.25) for forced expiratory volume z-score (zFEV1), and -0.29 SD (95% CI -0.47, -0.10) for zFEV1/FVC. For late preterm, mean differences with full-term controls were -0.02 SD (95% CI -0.17, 0.13), -0.12 SD (95% CI -0.29, 0.04) and -0.13 SD (95% CI -0.29, 0.02) for zFVC, zFEV1, and zFEV1/FVC, respectively. Examination of finer GA subgroups suggested an inverse non-linear association between lung function and GA, with the greatest impact on zFEV1 for those born extremely preterm. The subgroup means were GA<28 weeks: -0.98 SD; 28-<32 weeks: -0.29 SD; 32-<34 weeks: -0.44 SD; 34-<36 weeks: -0.10 SD; 36-<37weeks: -0.11 SD; term-born controls (≥37weeks): 0.02 SD. Corresponding means for zFEV1/FVC were -1.79, -0.44, -0.47, -0.48, -0.29, and -0.02. Adjustment for maternal pregnancy conditions and socioeconomic and lifestyle factors had no major impact on the relationship. Preterm birth is associated with airflow limitation in adult life. The association appears to be attributable predominantly to those born most immature, with only a modest decrease among those born preterm at later gestational ages.</p

    Endostatin inhibits VEGF-A induced osteoclastic bone resorption in vitro

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    BACKGROUND: Endostatin is a C-terminal fragment of collagen XVIII which is a component of basement membranes with the structural properties of both collagens and proteoglycans. Endostatin has a major role in angiogenesis which is intimately associated with bone development and remodeling. Signaling between the endothelial cells and the bone cells, for example, may have a role in recruitment of osteoclastic precursor cells. Our study aims at exploring a possibility that endostatin, either as a part of basement membrane or as a soluble molecule, may control osteoclastogenesis and osteoclastic bone resorption in vitro. METHODS: Rat pit formation assay was employed in order to examine the effect of endostatin alone or in combination with vascular endothelial growth factor-A (VEGF-A) on bone resorption in vitro. Effect of these agents on osteoclast differentiation in vitro was also tested. Osteoclastogenesis and the number of osteoclasts were followed by tartrate resistant acid phosphatase (TRACP) staining and resorption was evaluated by measuring the area of excavated pits. RESULTS: Endostatin inhibited the VEGF-A stimulated osteoclastic bone resorption, whereas endostatin alone had no effect on the basal resorption level in the absence of VEGF-A. In addition, endostatin could inhibit osteoclast differentiation in vitro independent of VEGF-A. CONCLUSION: Our in vitro data indicate that collagen XVIII/endostatin can suppress VEGF-A induced osteoclastic bone resorption to the basal level. Osteoclastogenesis is also inhibited by endostatin. The regulatory effect of endostatin, however, is not critical since endostatin alone does not modify the basal bone resorption

    Inhibition of Osteoclastogenesis by Mechanically Loaded Osteocytes: Involvement of MEPE

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    In regions of high bone loading, the mechanoresponsive osteocytes inhibit osteoclastic bone resorption by producing signaling molecules. One possible candidate is matrix extracellular phosphoglycoprotein (MEPE) because acidic serine- and aspartate-rich MEPE-associated motif peptides upregulate osteoprotegerin (OPG) gene expression, a negative regulator of osteoclastogenesis. These peptides are cleaved from MEPE when relatively more MEPE than PHEX (phosphate-regulating gene with homology to endopeptidases on the X chromosome) is present. We investigated whether mechanical loading of osteocytes affects osteocyte-stimulated osteoclastogenesis by involvement of MEPE. MLO-Y4 osteocytes were mechanically loaded by 1-h pulsating fluid flow (PFF; 0.7 ± 0.3 Pa, 5 Hz) or kept under static control conditions. Recombinant MEPE (0.05, 0.5, or 5 μg/ml) was added to some static cultures. Mouse bone marrow cells were seeded on top of the osteocytes to determine osteoclastogenesis. Gene expression of MEPE, PHEX, receptor activator of nuclear factor kappa-B ligand (RANKL), and OPG by osteocytes was determined after PFF. Osteocytes supported osteoclast formation under static control conditions. Both PFF and recombinant MEPE inhibited osteocyte-stimulated osteoclastogenesis. PFF upregulated MEPE gene expression by 2.5-fold, but not PHEX expression. PFF decreased the RANKL/OPG ratio at 1-h PFF treatment. Our data suggest that mechanical loading induces changes in gene expression by osteocytes, which likely contributes to the inhibition of osteoclastogenesis after mechanical loading of bone. Because mechanical loading upregulated gene expression of MEPE but not PHEX, possibly resulting in the upregulation of OPG gene expression, we speculate that MEPE is a soluble factor involved in the inhibition of osteoclastogenesis by osteocytes
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