775 research outputs found

    20 Jahre ‚Gäa e.V. - Vereinigung ökologischer Landbau’

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    For the understanding of ecological agriculture, knowledge of its roots is essential. Actual literature about this topic does not cover the history of ecological agriculture in East Germany especially if chronological development and individual motivation are seen as mutual dependent. The ecological organisation Gäa e.V. was founded in the GDR in 1989. Its origins were oppositional environmental groups working within the East German church. It developed own principles based on individual experience with unique aspects. It has established and integrated well in the German ecological agriculture structure after the reunification and the changed political background as an authentic representative of and for the East German ecological agriculture scene

    Superheated Microdrops as Cold Dark Matter Detectors

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    It is shown that under realistic background considerations, an improvement in Cold Dark Matter sensitivity of several orders of magnitude is expected from a detector based on superheated liquid droplets. Such devices are totally insensitive to minimum ionizing radiation while responsive to nuclear recoils of energies ~ few keV. They operate on the same principle as the bubble chamber, but offer unattended, continuous, and safe operation at room temperature and atmospheric pressure.Comment: 15 pgs, 4 figures include

    Disease progression in Plasmodium knowlesi malaria is linked to variation in invasion gene family members.

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    Emerging pathogens undermine initiatives to control the global health impact of infectious diseases. Zoonotic malaria is no exception. Plasmodium knowlesi, a malaria parasite of Southeast Asian macaques, has entered the human population. P. knowlesi, like Plasmodium falciparum, can reach high parasitaemia in human infections, and the World Health Organization guidelines for severe malaria list hyperparasitaemia among the measures of severe malaria in both infections. Not all patients with P. knowlesi infections develop hyperparasitaemia, and it is important to determine why. Between isolate variability in erythrocyte invasion, efficiency seems key. Here we investigate the idea that particular alleles of two P. knowlesi erythrocyte invasion genes, P. knowlesi normocyte binding protein Pknbpxa and Pknbpxb, influence parasitaemia and human disease progression. Pknbpxa and Pknbpxb reference DNA sequences were generated from five geographically and temporally distinct P. knowlesi patient isolates. Polymorphic regions of each gene (approximately 800 bp) were identified by haplotyping 147 patient isolates at each locus. Parasitaemia in the study cohort was associated with markers of disease severity including liver and renal dysfunction, haemoglobin, platelets and lactate, (r = ≥ 0.34, p =  <0.0001 for all). Seventy-five and 51 Pknbpxa and Pknbpxb haplotypes were resolved in 138 (94%) and 134 (92%) patient isolates respectively. The haplotypes formed twelve Pknbpxa and two Pknbpxb allelic groups. Patients infected with parasites with particular Pknbpxa and Pknbpxb alleles within the groups had significantly higher parasitaemia and other markers of disease severity. Our study strongly suggests that P. knowlesi invasion gene variants contribute to parasite virulence. We focused on two invasion genes, and we anticipate that additional virulent loci will be identified in pathogen genome-wide studies. The multiple sustained entries of this diverse pathogen into the human population must give cause for concern to malaria elimination strategists in the Southeast Asian region

    Association of folate receptor (FOLR1, FOLR2, FOLR3) and reduced folate carrier (SLC19A1) genes with meningomyelocele.

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    BACKGROUND: Meningomyelocele (MM) results from lack of closure of the neural tube during embryologic development. Periconceptional folic acid supplementation is a modifier of MM risk in humans, leading toan interest in the folate transport genes as potential candidates for association to MM. METHODS: This study used the SNPlex Genotyping (ABI, Foster City, CA) platform to genotype 20 single polymorphic variants across the folate receptor genes (FOLR1, FOLR2, FOLR3) and the folate carrier gene (SLC19A1) to assess their association to MM. The study population included 329 trio and 281 duo families. Only cases with MM were included. Genetic association was assessed using the transmission disequilibrium test in PLINK. RESULTS: A variant in the FOLR2 gene (rs13908), three linked variants in the FOLR3 gene (rs7925545, rs7926875, rs7926987), and two variants in the SLC19A1 gene (rs1888530 and rs3788200) were statistically significant for association to MM in our population. CONCLUSION: This study involved the analyses of selected single nucleotide polymorphisms across the folate receptor genes and the folate carrier gene in a large population sample. It provided evidence that the rare alleles of specific single nucleotide polymorphisms within these genes appear to be statistically significant for association to MM in the patient population that was tested

    AD51B in Familial Breast Cancer

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    Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C&gt;T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

    In Vivo Approaches Reveal a Key Role for DCs in CD4+ T Cell Activation and Parasite Clearance during the Acute Phase of Experimental Blood-Stage Malaria

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    Dendritic cells (DCs) are phagocytes that are highly specialized for antigen presentation. Heterogeneous populations of macrophages and DCs form a phagocyte network inside the red pulp (RP) of the spleen, which is a major site for the control of blood-borne infections such as malaria. However, the dynamics of splenic DCs during Plasmodium infections are poorly understood, limiting our knowledge regarding their protective role in malaria. Here, we used in vivo experimental approaches that enabled us to deplete or visualize DCs in order to clarify these issues. To elucidate the roles of DCs and marginal zone macrophages in the protection against blood-stage malaria, we infected DTx (diphtheria toxin)-treated C57BL/6.CD11c-DTR mice, as well as C57BL/6 mice treated with low doses of clodronate liposomes (ClLip), with Plasmodium chabaudi AS (Pc) parasites. The first evidence suggesting that DCs could contribute directly to parasite clearance was an early effect of the DTx treatment, but not of the ClLip treatment, in parasitemia control. DCs were also required for CD4+ T cell responses during infection. The phagocytosis of infected red blood cells (iRBCs) by splenic DCs was analyzed by confocal intravital microscopy, as well as by flow cytometry and immunofluorescence, at three distinct phases of Pc malaria: at the first encounter, at pre-crisis concomitant with parasitemia growth and at crisis when the parasitemia decline coincides with spleen closure. In vivo and ex vivo imaging of the spleen revealed that DCs actively phagocytize iRBCs and interact with CD4+ T cells both in T cell-rich areas and in the RP. Subcapsular RP DCs were highly efficient in the recognition and capture of iRBCs during pre-crisis, while complete DC maturation was only achieved during crisis. These findings indicate that, beyond their classical role in antigen presentation, DCs also contribute to the direct elimination of iRBCs during acute Plasmodium infection.São Paulo Research Foundation grants: (2011/24038-1 [MRDL], 2009/08559-1 [HBdS], CAPES/IGC 04/ 2012 [MRDL, CET])

    Probing Transit Timing Variation and Its Possible Origin with 12 New Transits of TrES-3b

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    We present 12 new transit light curves of the hot-Jupiter TrES-3b observed during 2012-2018 to probe the transit timing variation (TTV). By combining the midtransit times determined from these 12 transit data with those reestimated through uniform procedure from 71 transit data available in the literature, we derive new linear ephemeris and obtain the timing residuals that suggest the possibility of TTV in the TrES-3 system. However, the frequency analysis shows that the possible TTV is unlikely to be periodic, indicating the absence of an additional body in this system. To explore the other possible origins of TTV, the orbital decay and apsidal precession ephemeris models are fitted to the transit time data. We find the decay rate of TrES-3b to be (P) overt dot(q) = -4.1 +/- 3.1 ms( )yr(-1), and the corresponding estimated modified stellar tidal quality factor of Q(*)' similar to 1.11 x 10(5) is consistent with the theoretically predicted values for the stars hosting the hot-Jupiters. The shift in the transit arrival time of TrES-3b after 11 years is expected to be T-s(hift) similar to 69.55 s, which is consistent with the rms of the timing residuals. Besides, we find that the apsidal precession ephemeris model is statistically less probable than the other considered ephemeris models. It is also discussed that despite the fact that the linear ephemeris model appears to be the most plausible model to represent the transit time data, the possibility of the orbital decay cannot be completely ruled out in the TrES-3 system. To confirm this, further high-precision and high-cadence follow-up observation of transits of TrES-3b would be important.University Grants Commission (UGC), New Delhi [UGC-MRP 43-521/2014(SR)]; IUCAA, Pune through IUCAA Associateship Programme; Ministry of Science and Technology, Taiwan [MOST 106-2112-M-007-006-MY3]; Department of Science and Technology (DST), India through the Indo-Austria project on transiting exoplanets [INT/AUSTRIA/BMWF/P-14]; TUBITAK (Scientific and Technological Research Council of Turkey) [113F353]; National Planning Agency (DPT) of Turkey [DPT-2007K120660]; Scientific Research Projects Coordination Unit of Istanbul University [3685]; TUBITAK [13CT100-523, 13CT100537]; Canakkale Onsekiz Mart University Astrophysics Research Center; Ulupinar Observatory; Istanbul University Observatory Research and Application Center; [VEGA 2/0031/18]; [APVV-15-0458]We thank the anonymous referee for useful comments that improved the quality of the paper. We also thank J.Z. Gazak, D. Foreman-Mackey, and D. Ragozzine for their valuable suggestions and discussions, which have been very helpful in improving the paper. We thank the staff at IAO, Hanle and CREST (IIA), Hosakote, as well as at DFOT (ARIES), Nainital, for providing support during the observations. The time allocation committees of the HCT, DFOT, and AZT-11 are gratefully acknowledged for providing the observation times. P.T. and V.K.M. acknowledge the University Grants Commission (UGC), New Delhi, for providing the financial support through Major Research Project no. UGC-MRP 43-521/2014(SR). P.T. expresses his sincere thanks to IUCAA, Pune, for providing the supports through IUCAA Associateship Programme. I.G.J. acknowledges funding from the Ministry of Science and Technology, Taiwan, through the grant No. MOST 106-2112-M-007-006-MY3. Y.C.J. acknowledges the Department of Science and Technology (DST), India, for their support through the Indo-Austria project on transiting exoplanets, INT/AUSTRIA/BMWF/P-14. M.V. would like to thank the project VEGA 2/0031/18 and APVV-15-0458. C.P. acknowledges the funding from TUBITAK (Scientific and Technological Research Council of Turkey) under grant No. 113F353. C.P. also thanks Canakkale Onsekiz Mart University Astrophysics Research Center, Ulupinar Observatory, and Istanbul University Observatory Research and Application Center for their support and allowing use of T122 and T60, which were supported partly by the National Planning Agency (DPT) of Turkey (project DPT-2007K120660 carried out Canakkale Onsekiz Mart University) and the Scientific Research Projects Coordination Unit of Istanbul University (project no. 3685). C. P. thanks TUBITAK for a partial support in using the T100 telescope with project numbers 13CT100-523 and 13CT100537. We thank N.P. Gibson, J.W. Lee, and D. Ricci for sharing the transit light curves of TrES-3b with us. We are also thankful to A. Sozzetti, K.D. Colon, P. Kundurthy, and J.D. Turner for making their transit light curves publicly available
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