8 research outputs found
The three-dimensional prey field of the northern krill, Meganyctiphanes norvegica, and the escape responses of their copepod prey
In the north Atlantic, Meganyctiphanes norvegica feeds predominantly on copepods, including Calanus spp. To quantify its perceptual field for prey, and the sensory systems underlying prey detection, the responses of tethered krill to free-swimming Calanus spp. were observed in 3D using silhouette video imaging. An attackâwhich occurred despite the krillâs being tetheredâwas characterized by a pronounced movement of the krillâs antennae towards the target, followed by a propulsion and opening of the feeding basket. Frequency distributions of prey detection distances were significantly different in the light vs. the dark, with median values of 26.5 mm and 19.5 mm, respectively. There were no significant differences in the angles at which prey were detected by krill (relative to the predatorâs longitudinal body axis) in the light vs. the dark. Prey detections were symmetrically distributed on either side of the predator, in both light and dark. However, significant asymmetry was found in the dorsalâventral direction with 80% of the prey detections located below the midline of the krillâs body axis and, given the placement and orientation of the compound eyes, presumably outside its visual field of view. This indicates that, at least under these conditions, vision was not the main sensory modality involved in the detection of active prey by M. norvegica. However, under some circumstances, vision may provide supplemental information. Avoidance responses of copepod prey were nearly twice the velocity of their nominal background swimming speed (153 Âą 48 and 85 Âą 75 mm sâ1, respectively), on average taking them 43 Âą 16 mm away from the predator. This is far beyond the krillâs perceptual range, suggesting that the escape reaction provides an effective deterrent to predation (although perhaps less so for free-swimming krill). This information can be used to parameterize models that assess the role of krill as predators in marine ecosystems
The three-dimensional prey field of the northern krill, Meganyctiphanes norvegica, and the escape responses of their copepod prey
Validation of FRAX and the impact of self-reported falls among elderly in a general population: the HUNT study, Norway
Summary
Fracture Risk Assessment Tool (FRAX) without bone mineral density (BMD) for hip fracture prediction was validated in a Norwegian population 50â90 years. Fracture risk increased with higher FRAX score, and the observed number of hip fractures agreed well with the predicted number, except for the youngest and oldest men.
Self-reported fall was an independent risk factor for fracture in women.
Introduction
The primary aim was to validate FRAX without BMD for hip fracture prediction in a Norwegian population of men and women 50â90 years. Secondary, to study whether information of falls could improve prediction of fractures in the subgroup aged 70â90 years.
Methods
Data were obtained from the third survey of the Nord-Trøndelag Health Study (HUNT3), the fracture registry in Nord-Trøndelag, and the Norwegian Prescription Database (NorPD), including 15,432 women and 13,585 men.
FRAX hip without BMD was calculated, and hip fractures were registered for a median follow-up of 5.2 years.
The number of estimated and observed fractures was assessed, ROC curves with area under the curve (AUC), and Cox regression analyses. For the group aged 70â90 years, self-reported falls the last year before HUNT3 were included in the Cox regression model.
Results
The risk of fracture increased with higher FRAX score. When FRAX groups were categorized in a 10-year percentage risk for hip fracture as follows, <4, 4â7.9, 8â11.9, and âĽ12%, the hazard ratio (HR) for hip fracture between the lowest and the highest group was 17.80 (95% CI: 12.86â24.65) among women and 23.40 (13.93â39.30) in men. Observed number of hip fractures agreed quite well with the predicted number, except for the youngest and oldest men. AUC was 0.81 (0.78â0.83) for women and 0.79 (0.76â0.83) for men. Self-reported fall was an independent risk factor for fracture in women (HR 1.64, 1.20â2.24), and among men, this was not significant (1.09, 0.65â1.83).
Conclusions
FRAX without BMD predicted hip fracture reasonably well. In the age group 70â90 years, falls seemed to imply an additional risk among women
Predictors of Short- and Long-Term Mortality in Males and Females with Hip Fracture - A Prospective Observational Cohort Study
Higher vitamin B12 levels in neurodevelopmental disorders than in healthy controls and schizophrenia
Primary immunodeficiency diseases: Genomic approaches delineate heterogeneous Mendelian disorders
BACKGROUND: Primary immunodeficiency diseases (PIDDs) are clinically and genetically heterogeneous disorders thus far associated with mutations in more than 300 genes. The clinical phenotypes derived from distinct genotypes may overlap. Genetic etiology can be a prognostic indicator of disease severity and can influence treatment decisions. OBJECTIVE: To investigate the ability of whole-exome screening methods to detect disease-causing variants in individuals with PIDDs. METHODS: Individuals with PIDDs from 278 families from 22 countries were investigated using whole-exome sequencing (WES). Computational CNV prediction pipelines and an exome-tiling chromosomal microarray were also applied to identify intragenic copy number variants (CNVs). Analytic approaches initially focused on 475 known or candidate PIDD genes, but were non-exclusive and were further tailored based upon clinical data, family history and immunophenotyping. RESULTS: A likely molecular diagnosis was achieved in 110 (40%) unrelated probands. Clinical diagnosis was revised in about half (60/110) and management was directly altered in nearly a quarter (26/110) of families based on the molecular findings. Twelve PIDD-causing CNVs were detected, including seven smaller than 30 Kb that would not have been detected with conventional diagnostic CNV arrays. CONCLUSION: This high-throughput genomic approach enabled detection of disease-related variants in unexpected genes, permitted detection of low-grade constitutional, somatic and revertant mosaicism, and provided evidence of a mutational burden in mixed PIDD immunophenotypes