27 research outputs found
Comparative Natural History of Visual Function From Patients With Biallelic Variants in BBS1 and BBS10.
The purpose of this study was to compare the natural history of visual function change in cohorts of patients affected with retinal degeneration due to biallelic variants in Bardet-Biedl syndrome genes: BBS1 and BBS10.
Patients were recruited from nine academic centers from six countries (Belgium, Canada, France, New Zealand, Switzerland, and the United States). Inclusion criteria were: (1) female or male patients with a clinical diagnosis of retinal dystrophy, (2) biallelic disease-causing variants in BBS1 or BBS10, and (3) measures of visual function for at least one visit. Retrospective data collected included genotypes, age, onset of symptoms, and best corrected visual acuity (VA). When possible, data on refractive error, fundus images and autofluorescence (FAF), optical coherence tomography (OCT), Goldmann kinetic perimetry (VF), electroretinography (ERG), and the systemic phenotype were collected.
Sixty-seven individuals had variants in BBS1 (n = 38; 20 female patients and 18 male patients); or BBS10 (n = 29; 14 female patients and 15 male patients). Missense variants were the most common type of variants for patients with BBS1, whereas frameshift variants were most common for BBS10. When ERGs were recordable, rod-cone dystrophy (RCD) was observed in 82% (23/28) of patients with BBS1 and 73% (8/11) of patients with BBS10; cone-rod dystrophy (CORD) was seen in 18% of patients with BBS1 only, and cone dystrophy (COD) was only seen in 3 patients with BBS10 (27%). ERGs were nondetectable earlier in patients with BBS10 than in patients with BBS1. Similarly, VA and VF declined more rapidly in patients with BBS10 compared to patients with BBS1.
Retinal degeneration appears earlier and is more severe in BBS10 cases as compared to those with BBS1 variants. The course of change of visual function appears to relate to genetic subtypes of BBS
Physiography influences honeybee queen's choice of mating place (Apis mellifera carnica Pollmann)
Experiments were carried out in a steep mountain valley between Mariazell and Wildalpen in Austria. In the centre of the area Cordovan (cd) drones were kept, while black drones were flying in the periphery. The virgin queens (homozygous cd/cd) were placed in four directions at different distances (0, 2, 4, 6, 8 km) from the centre and permitted to freely perform mating flights. All 15 queens in the North had only black (cd/+) worker offspring. In the west, east and south the proportion of queens with cd/cd progeny in and near the centre (up to 2 km) was larger than that of the queens further away (4 and 6 km). The results of queens placed in the east compared to western queens indicated a preference for mating flight directions down the valley, towards the highest light intensity. So the physiography seems to have a major influence on the queens'choice of mating place. In regard to practical honeybee breeding the close similarity between the orientation of queens demonstrated in these experiments and the orientation of drones underline the validity of the general rules for mating yards as established previously by F and H Ruttner
Honeydew content and electrical conductivity of honey
During the honey flow from honeydew in Lunz am See, Austria, between June 30th and July 21 st 1987, samples of returning fieldbees from 3 specially prepared colonies (without any reserve of honey and pollen) were collected daily at various times. The bee samples were killed in liquid nitrogen and stored at -18°C. At the end of the experiment honey samples were also taken from each comb of the colonies. The following data were collected from the bees: weight of the honeysac, sugar content in the honeysac (Anthron method = total sugar analysis) and the botanical origin of the honeysac content (on the basis of pollen grains and fungus spores). Measurements of the honey samples were as follows : electrical conductivity, number of pollen grains (nectar plants and nectarless plants) and honeydew components (fungus spores) in the honey sediment per mg sugar. Significant correlations were found between electric conductivity and sugar content originating from honeydew and number of honeydew components per mg sugar in the honey (fig 1 A, B). Significant negative correlations were also found between the percentage of honeydew sugar in the honey and the number of honeydew components in the honey sediment per mg sugar, the number of pollen grains from wind-pollinating plants per mg sugar and the relation of pollen grains of nectar plants to pollen of nectarless plants per mg sugar (fig 2A, B, C). The result of higher honeydew content in the honey is a significant higher electric conductivity, a lower relation between the number of pollen grains from nectarplants to pollen of nectarless plants per mg sugar and a general lower content of sediment components per mg sugar in the honey
Globalisering bijenhandel : wereldwijd
Oorspronkelijk kwamen de honingbijen van het genus Apis alleen voor in de 'Oude Wereld'. De Westelijke honingbij of de soort Apis mellifera en haar talrijke subspecies of ondersoorten en rassen, waren te vinden in Europa, van de Atlantische Oceaan tot aan de Oeral, in Voor-Azië tot in Perzië, het hedendaagse Iran, en op het gehele Afrikaanse continent. Maar de mens verspreidde deze soort verder in geheel Azië, in de beide Amerika's, in Australië en de eilanden van Oceanië
Untersuchungen über das Zuckerspektrum in Honigblaseninhalt und Honig
The sugar spectrum was investigated by HPLC in honey-sac contents of 52 fieldbees and in honey of a specially prepared colony. The origin of the honey-sac content was determined from the pollen species. The sugar spectrum has a typical frequency from the most frequent honey plants. A good correlation between the honey-sac content of the fieldbees and the honey produced in the experimental hive was found by consideration of enzyme effect (tables II and III). Liquid honeydew collected had a high sucrose content (49.42 ± 5.56%), but honeydew cristallized in the honey-sac of the stored bees (-18°C) within less than 2 wk had a lower sucrose (20.47 ± 4.78%) but a much higher melecitose content (41.12 ± 2.19% to 19.99 ± 4.10% in honeydew liquid). In this colony more than 90% of sucrose and only 30% of the melezitose collected from the bees could be inverted. The sugar spectrum of the honey-sac content provides information about the botanical origin. On the basis of the sugar spectrum of the honey the botanical origin can also be estimated