69 research outputs found

    Methoden zur Verbesserung der Vegetationszusammensetzung in ökologisch bewirtschaftetem Dauergrünland

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    In der ökologischen Grünlandbewirtschaftung werden artenreiche Bestände mit Standort angepassten und möglichst wertvollen Futterarten angestrebt. Dennoch sind in der Praxis oftmals stark Weidelgras betonte Bestände anzutreffen. Im Vergleich zur Neuansaat sind Nachsaaten deutlich kostengünstiger. Daher wurden im Sommer 2007 auf 8 ökologisch bewirtschafteten Betrieben Nord-Westdeutschlands Nachsaatversuche mit unterschiedlicher Technik (Schlitzsaat und Bandfrässaat) und ausgewählten Arten angelegt. Hierbei würden 5 Gramineen (Lolium perenne, Phleum pratense, Festuca rubra, Dactylis glomerata) und auf drei Standorten in Niedersachsen zusätzlich Festulolium, eine Neuzüchtung aus Festuca- und Lolium-Gattungen sowie eine Futterleguminose (Lotus corniculatus) geprüft. Deutsches Weidelgras und Wiesenlieschgras, aber auch Wiesenschweidel ließen sich mit beiden Nachsaatverfahren meistens gut etablieren. Durch die stark Narben schädigende Bandfrässaat lassen sich auch konkurrenzschwächere Arten wie Knaulgras, Rotschwingel und sogar Hornklee nachhaltig etablieren. Voraussetzung für dauerhaft erfolgreiche Nachsaaten sind eine ausreichende Wasser- und Nährstoffverfügbarkeit sowie allgemein günstige Standortbedingungen. Die besten Ergebnisse wurden mit der Bandfrässaat auf den sandigeren Standorten, während das Frässaatverfahren für schwere Marsch- und Tonböden nur bedingt geeignet ist, weil die Bodenstruktur unter ungünstigen Bedingungen zu stark geschädigt wird

    Growing up with cancer: Accommodating the effects of cancer into young people’s social lives.

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    Adolescence and young adulthood are transitional periods of rapid and dramatic personal change. Few events can cause as unpredictable and challenging alterations to this process as the onset of a serious illness, such as cancer. Although we know much about the physical and psychological consequences of having cancer at this time, we know little about the effect of cancer on young people’s relationships. We conducted interviews with 15 women and 12 men aged between 16 and 29 years, who had survived cancer. Our findings demonstrate that the experience of cancer and how it affects relationships is complex. It arrests young people’s development by increasing their dependence on parents, giving them life experiences unavailable to peers, and complicating the process of establishing new relationships. However, it also accelerates development by facilitating closer and more mature relationships with parents and giving young people wisdom and insight not shared by peers. Cancer profoundly shapes how young people conduct their relationships. These changes require ongoing accommodation by young people with cancer, their parents, peers, and new acquaintances

    Frequent deletion of the CDKN2A locus in chordoma: analysis of chromosomal imbalances using array comparative genomic hybridisation

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    The initiating somatic genetic events in chordoma development have not yet been identified. Most cytogenetically investigated chordomas have displayed near-diploid or moderately hypodiploid karyotypes, with several numerical and structural rearrangements. However, no consistent structural chromosome aberration has been reported. This is the first array-based study characterising DNA copy number changes in chordoma. Array comparative genomic hybridisation (aCGH) identified copy number alterations in all samples and imbalances affecting 5 or more out of the 21 investigated tumours were seen on all chromosomes. In general, deletions were more common than gains and no high-level amplification was found, supporting previous findings of primarily losses of large chromosomal regions as an important mechanism in chordoma development. Although small imbalances were commonly found, the vast majority of these were detected in single cases; no small deletion affecting all tumours could be discerned. However, the CDKN2A and CDKN2B loci in 9p21 were homo- or heterozygously lost in 70% of the tumours, a finding corroborated by fluorescence in situ hybridisation, suggesting that inactivation of these genes constitute an important step in chordoma development

    Possible modification of BRSK1 on the risk of alkylating chemotherapy-related reduced ovarian function

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    STUDY QUESTION: Do genetic variations in the DNA damage response pathway modify the adverse effect of alkylating agents on ovarian function in female childhood cancer survivors (CCS)? SUMMARY ANSWER: Female CCS carrying a common BR serine/threonine kinase 1 (BRSK1) gene variant appear to be at 2.5-fold increased odds of reduced ovarian function after treatment with high doses of alkylating chemotherapy. WHAT IS KNOWN ALREADY: Female CCS show large inter-individual variability in the impact of DNA-damaging alkylating chemotherapy, given as treatment of childhood cancer, on adult ovarian function. Genetic variants in DNA repair genes affecting ovarian function might explain this variability. STUDY DESIGN, SIZE, DURATION: CCS for the discovery cohort were identified from the Dutch Childhood Oncology Group (DCOG) LATER VEVO-study, a multi-centre retrospective cohort study evaluating fertility, ovarian reserve and risk of premature menopause among adult female 5-year survivors of childhood cancer. Female 5-year CCS, diagnosed with cancer and treated with chemotherapy before the age of 25 years, and aged 18 years or older at time of study were enrolled in the current study. Results from the discovery Dutch DCOG-LATER VEVO cohort (n = 285) were validated in the pan-European PanCareLIFE (n =465) and the USA-based St. Jude Lifetime Cohort (n = 391). PARTICIPANTS/MATERIALS, SETTING, METHODS: To evaluate ovarian function, anti-Miillerian hormone (AMH) levels were assessed in both the discovery cohort and the replication cohorts. Using additive genetic models in linear and logistic regression, five genetic variants involved in DNA damage response were analysed in relation to cyclophosphamide equivalent dose (CED) score and their impact on ovarian function. Results were then examined using fixed-effect meta-analysis. MAIN RESULTS AND THE ROLE OF CHANCE: Meta-analysis across the three independent cohorts showed a significant interaction effect (P= 3.0 x 10(-4)) between rs11668344 of BRSK 1 (allele frequency = 0.34) among CCS treated with high-dose alkylating agents (CED score >= 8000 mg/m(2)), resulting in a 2.5-fold increased odds of a reduced ovarian function (lowest AMH tertile) for CCS carrying one G allele compared to CCS without this allele (odds ratio genotype AA: 2.01 vs AG: 5.00). LIMITATIONS, REASONS FOR CAUTION: While low AMH levels can also identify poor responders in assisted reproductive technology, it needs to be emphasized that AMH remains a surrogate marker of ovarian function. WIDER IMPLICATIONS OF THE FINDINGS: Further research, validating our findings and identifying additional risk contributing genetic variants, may enable individualized counselling regarding treatment-related risks and necessity of fertility preservation procedures in girls with cancer

    A survey of fertility preservation options available to cancer patients around the globe

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    Purpose: Oncofertility focuses on providing fertility and endocrine-sparing options to patients who undergo life-preserving but gonadotoxic cancer treatment. The resources needed to meet patient demand often are fragmented along disciplinary lines. We quantify assets and gaps in oncofertility care on a global scale. Methods: Survey-based questionnaires were provided to 191 members of the Oncofertility Consortium Global Partners Network, a National Institutes of Health–funded organization. Responses were analyzed to measure trends and regional subtleties about patient oncofertility experiences and to analyze barriers to care at sites that provide oncofertility services. Results: Sixty-three responses were received (response rate, 25%), and 40 were analyzed from oncofertility centers in 28 countries. Thirty of 40 survey results (75%) showed that formal referral processes and psychological care are provided to patients at the majority of sites. Fourteen of 23 respondents (61%) stated that some fertility preservation services are not offered because of cultural and legal barriers. The growth of oncofertility and its capacity to improve the lives of cancer survivors around the globe relies on concentrated efforts to increase awareness, promote collaboration, share best practices, and advocate for research funding. Conclusion: This survey reveals global and regional successes and challenges and provides insight into what is needed to advance the field and make the discussion of fertility preservation and endocrine health a standard component of the cancer treatment plan. As the field of oncofertility continues to develop around the globe, regular assessment of both international and regional barriers to quality care must continue to guide process improvements

    Impact of treatment processes on the removal of perfluoroalkyl acids from the drinking water production chain

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    The behavior of polyfluoralkyl acids (PFAAs) from intake (raw source water) to finished drinking water was assessed by taking samples from influent and effluent of the several treatment steps used in a drinking water production chain. These consisted of intake, coagulation, rapid sand filtration, dune passage, aeration, rapid sand filtration, ozonation, pellet softening, granular activated carbon (GAC) filtration, slow sand filtration, and finished drinking water. In the intake water taken from the Lek canal (a tributary of the river Rhine), the most abundant PFAA were PFBA (perfluorobutanoic acid), PFBS (perfluorobutane sulfonate), PFOS (perfluorooctane sulfonate), and PFOA (perfluorooctanoic acid). During treatment, longer chain PFAA such as PFNA (perfluorononanoic acid) and PFOS were readily removed by the GAC treatment step and their GAC effluent concentrations were reduced to levels below the limits of quantitation (LOQ) (0.23 and 0.24 ng/L for PFOS and PFNA, respectively). However, more hydrophilic shorter chain PFAA (especially PFBA and PFBS) were not removed by GAC and their concentrations remained constant through treatment. A decreasing removal capacity of the GAC was observed with increasing carbon loading and with decreasing carbon chain length of the PFAAs. This study shows that none of the treatment steps, including softening processes, are effective for PFAA removal, except for GAC filtration. GAC can effectively remove certain PFAA from the drinking water cycle.The enrichment of branched PFOS and PFOA isomers relative to non branched isomers during GAC filtration was observed during treatment. The finished water contained 26 and 19 ng/L of PFBA and PFBS. Other PFAAs were present in concentrations below 4.2 ng/L The concentrations of PFAA observed in finished waters are no reason for concern for human health as margins to existing guidelines are sufficiently large

    In vitro 17ss-oestradiol release as a marker for follicular survival in cryopreserved intact bovine ovaries.

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    Item does not contain fulltextTransplantation of cryopreserved intact ovaries from cancer patients is a technically challenging option for restoring fertility after sterilizing cancer therapy. In this paper we describe an assay based on 17ss-oestradiol (oestradiol) production, to monitor the functional damage sustained by the ovarian tissue during the freeze/thawing procedure. To this end, fresh bovine ovarian cortical biopsies were cultured in vitro for 7 days. As a control, the oestradiol release of biopsies that had sustained maximal cryodamage was analyzed. In addition the oestradiol release by cortical biopsies from two ME2SO perfused and cryopreserved intact ovaries was analyzed. Oestradiol production could be measured in culture supernatants, while oestradiol release of maximal cryo-damaged biopsies was at background levels. In vitro oestradiol release by cortical biopsies can be used as a functional marker for cryo-damage and indicates that our assay is suitable to optimize the cryopreservation procedure of intact ovaries
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