204 research outputs found
Bewonersparticipatie in het openbaar groenbeheer : 'State of the art' na vijf jaar zelfbeheer in de wijk EVA-Lanxmeer (Culemborg)
De wijk EVA-Lanxmeer (1997) is een duurzame woon- en werkwijk in Culemborg, op een grondwaterwingebied van Vitens. Het is een voorbeeldproject op het gebied van duurzame stedenbouw en participatief beleid. Het wordt door gemeenten en groepen burgers in binnen- en buitenland gebruikt om inspiratie, kennis en ervaring op te doen en uit te wisselen op het gebied van innovatief denken binnen de eigen gemeentelijke organisatie. Bewoners onderhouden zelf een belangrijk deel van het wijkgroen op een ecologische wijze. Zij doen dat in samenwerking en overleg met de gemeente Culemborg en Waterwinbedrijf Vitens. De meeste bewoners hebben sterk het gevoel dat het zelfbeheer de kwaliteit en diversiteit van het groen in de wijk verhoogt. De gezamenlijke werkzaamheden maken ongedwongen ontmoetingen met andere bewoners in de wijk mogelijk
Coamplification of DAD-R, SOX5, and EKI1 in human testicular seminomas, with specific overexpression of DAD-R, correlates with reduced levels of apoptosis and earlier clinical manifestation
Seminomas and nonseminomas represent the invasive stages of testicular
(TGCTs) of adolescents and adults. Although TGCTs are characterized by
extra copies of the short arm of chromosome 12, the genetic basis for gain
of 12p in the pathogenesis of this cancer is not yet understood. We have
demonstrated that gain of 12p is related to invasive growth and that
amplification of specific 12p sequences, i.e., 12p11.2-p12.1, correlates
with reduced apoptosis in the tumors. Here we show that three known genes
map within the newly determined shortest region of overlap of
amplification (SROA): DAD-R, SOX5, and EKI1. Whereas EKI1 maps close to
the telomeric region of the SROA, DAD-R is the first gene at the
centromeric region within the 12p amplicon. Although all three genes are
amplified to the same level within the SROA, expression of DAD-R is
significantly up-regulated in seminomas with the restricted 12p
amplification compared with seminomas without this amplicon. DAD-R is also
highly expressed in nonseminomas of various histologies and derived cell
lines, both lacking such amplification. This finding is of particular
interest because seminomas with the restricted 12p amplification and
nonseminomas are manifested clinically in the third decade of life and
show a low degree of apoptosis. In contrast, seminomas lacking a
restricted 12p amplification, showing significantly lower levels of DAD-R
with pronounced apoptosis, manifest clinically in the fourth decade of
life. A low level of DAD-R expression is also observed in normal
testicular parenchyma and in parenchyma containing the precursor cells of
this cancer, i.e., carcinoma in situ. Therefore, elevated DAD-R expression
in seminomas and nonseminomas correlates with invasive growth and a
reduced level of apoptosis associated with an earlier clinical
presentation. These data implicate DAD-R as a candidate gene responsible
in part for the pathological effects resulting from gain of 12p sequences
in TGCTs. In addition, our results also imply differences in expression
regulation of DAD-R between seminomas and nonseminomas
Restricted 12p amplification and RAS mutation in human germ cell tumors of the adult testis
Human testicular germ-cell tumors of young adults (TGCTs), both seminomas
and nonseminomas, are characterized by 12p overrepresentation, mostly as
isochromosomes, of which the biological and clinical significance is still
unclear. A limited number of TGCTs has been identified with an additional
high-level amplification of a restricted region of 12p including the K-RAS
proto-oncogene. Here we show that the incidence of these restricted 12p
amplifications is approximately 8% in primary TGCTs. Within a single cell
formation of i(12p) and restricted 12p amplification is mutually
exclusive. The borders of the amplicons cluster in short regions, and the
amplicon was never found in the adjacent carcinoma in situ cells.
Seminomas with the restricted 12p amplification virtually lacked apoptosis
and the tumor cells showed prolonged in vitro survival like seminoma cells
with a mutated RAS gene. However, no differences in proliferation index
between these different groups of seminomas were found. Although patients
with a seminoma containing a homogeneous restricted 12p amplification
presented at a significantly younger age than those lacking it, the
presence of a restricted 12p amplification/RAS mutation did not predict
the stage of the disease at clinical presentation and the treatment
response of primary seminomas. In 55 primary and metastatic tumors from 44
different patients who failed cisplatinum-based chemotherapy, the
restricted 12p amplification and RAS mutations had the same incidence a
Vortex Motion Noise in Micrometre-Sized Thin Films of the Amorphous Nb0.7Ge0.3 Weak-Pinning Superconductor
We report high-resolution measurements of voltage (V) noise in the mixed
state of micrometre-sized thin films of amorphous Nb0.7Ge0.3, which is a good
representative of weak-pinning superconductors. There is a remarkable
difference between the noise below and above the irreversibility field Birr.
Below Birr, in the presence of measurable pinning, the noise at small applied
currents resembles shot noise, and in the regime of flux flow at larger
currents decreases with increasing voltage due to a progressive ordering of the
vortex motion. At magnetic fields B between Birr and the upper critical field
Bc2 flux flow is present already at vanishingly small currents. In this regime
the noise scales with (1-B/Bc2)^2 V^2 and has a frequency (f) spectrum of 1/f
type. We interpret this noise in terms of the properties of strongly driven
depinned vortex systems at high vortex density.Comment: 8 pages, 5 figures, version accepted for publication in PR
Stem cell factor receptor (c-KIT) codon 816 mutations predict development of bilateral testicular germ-cell tumors
Testicular germ-cell tumors (TGCTs) of adolescents and adults originate
from intratubular germ cell neoplasia (ITGCN), which is composed of the
malignant counterparts of embryonal germ cells. ITGCN cells are
characterized, among others, by the presence of stem cell factor receptor
c-KIT. Once established, ITGCN will always progress to invasiveness.
Approximately 2.5-5% of patients with a TGCT will develop bilateral
disease and require complete castration, resulting in infertility, a need
for lifelong androgen replacement, and psychological stress. To date, the
only way to predict a contralateral tumor is surgical biopsy of the
contralateral testis to demonstrate ITGCN. We did a retrospective study of
224 unilateral and 61 proven bilateral TGCTs (from 46 patients, in three
independently collected series in Europe) for the presence of activating
c-KIT codon 816 mutations. A c-KIT codon 816 mutation was found in three
unilateral TGCT (1.3%), and in 57 bilateral TGCTs (93%; P < 0.0001). In
the two wild-type bilateral tumors for which ITGCN was available, the
preinvasive cells contained the mutation. The mutations were somatic in
origin and identical in both tumors. We conclude that somatic activating
codon 816 c-KIT mutations are associated with development of bilateral
TGCT. Detection of c-KIT codon 816 mutations in unilateral TGCT identifies
patients at risk for bilateral disease. These patients may undergo
tailored treatment to prevent the development of bilateral disease, with
retention of testicular hormonal function
Plant-RRBS, a bisulfite and next-generation sequencing-based methylome profiling method enriching for coverage of cytosine positions
Background: Cytosine methylation in plant genomes is important for the regulation of gene transcription and transposon activity. Genome-wide methylomes are studied upon mutation of the DNA methyltransferases, adaptation to environmental stresses or during development. However, from basic biology to breeding programs, there is a need to monitor multiple samples to determine transgenerational methylation inheritance or differential cytosine methylation. Methylome data obtained by sodium hydrogen sulfite (bisulfite)-conversion and next-generation sequencing (NGS) provide genome- wide information on cytosine methylation. However, a profiling method that detects cytosine methylation state dispersed over the genome would allow high-throughput analysis of multiple plant samples with distinct epigenetic signatures. We use specific restriction endonucleases to enrich for cytosine coverage in a bisulfite and NGS-based profiling method, which was compared to whole-genome bisulfite sequencing of the same plant material.
Methods: We established an effective methylome profiling method in plants, termed plant-reduced representation bisulfite sequencing (plant-RRBS), using optimized double restriction endonuclease digestion, fragment end repair, adapter ligation, followed by bisulfite conversion, PCR amplification and NGS. We report a performant laboratory protocol and a straightforward bioinformatics data analysis pipeline for plant-RRBS, applicable for any reference-sequenced plant species.
Results: As a proof of concept, methylome profiling was performed using an Oryza sativa ssp. indica pure breeding line and a derived epigenetically altered line (epiline). Plant-RRBS detects methylation levels at tens of millions of cytosine positions deduced from bisulfite conversion in multiple samples. To evaluate the method, the coverage of cytosine positions, the intra-line similarity and the differential cytosine methylation levels between the pure breeding line and the epiline were determined. Plant-RRBS reproducibly covers commonly up to one fourth of the cytosine positions in the rice genome when using MspI-DpnII within a group of five biological replicates of a line. The method predominantly detects cytosine methylation in putative promoter regions and not-annotated regions in rice.
Conclusions: Plant-RRBS offers high-throughput and broad, genome- dispersed methylation detection by effective read number generation obtained from reproducibly covered genome fractions using optimized endonuclease combinations, facilitating comparative analyses of multi-sample studies for cytosine methylation and transgenerational stability in experimental material and plant breeding populations
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