Developments at the Cologne 10 MV AMS system for 60Fe measurements

The focus of this thesis is the development of 60Fe isotopic ratio measurements with Accelerator Mass Spectrometry (AMS) at the Cologne 10 MV tandem accelerator system. Within this work an extensive range of investigations and developments of the 10 MV AMS system were conducted. These increased the reachable statistics and enables the necessary system stability to allow long-term measurements and especially low-level isotopic ratio measurements. The comparison between initial and latest conducted 60Fe AMS measurements revealed a significant decrease of required measurement duration by at least 95 per cent, a factor of 20, to 1.49 days on average for a theoretical 60Fe event of a 1E-16 60Fe/Fe ratio. Therefore, the system is now capable of similar statistics in reasonable measurement duration as established AMS laboratories. For the first time, full reference sample sequence measurements were conducted at the system which is a mandatory criterion for a functioning AMS system. Furthermore, the data acquisition was coupled to the 10 MV AMS control system. With that, automated AMS measurements of 60Fe and 14C were conducted for the first time at the 10 MV AMS system. The key component for isobar suppression of 60Ni in 60Fe measurements at the Cologne setup is the gas-filled magnet. For the optimization of the used gas parameters for 60Fe measurements and for a deeper understanding of the inner processes of particles passing the gas-filled magnet, a wide range of investigations were conducted. Thereby, the ion beam shape of 60Ni particles a from a 60Fe blank material was investigated after the gas-filled magnet and for the first time within the gas-filled magnet for different gas pressures and gas types. The measurements in the gas-filled magnet investigated the beam shape and trajectory in the dispersive axis. For the first time, it was possible to measure the ions deviation from the magnet optical axis which increases with increased gas pressure to outer trajectories. In nitrogen gas, the ion widths show a characteristic shape including a minimum in comparison to the gas pressure. For the first time, it was determined that the minimum of this shape shifts for different passed gas paths. The measurements with helium gas showed smaller positional deviations from the optical axis and significantly larger widths for the measured gas pressure range. The analysis of the two-dimensional profiles after the magnet was used to determine the optimal gas settings in terms of transmission for a subsequent symmetrical detector window. From the investigations, the optimum gas parameter from the measured options is nitrogen gas at 3 mbar gas pressure. The additional measurements of the separation factor between 60Fe and 60Ni in dependence of different nitrogen gas pressures revealed an increase in separation factor up to a pressure of 5 mbar with increased gas pressure. Finally, the two-dimensional profile of 60Fe was analyzed and compared to the available subsequent detector entrance windows. It revealed that the high transmission loss in the initially conducted 60Fe measurements were caused by the size of the respective entrance window. The experiments were simulated with an in-house code, which was further developed within this thesis, and an externally available simulation code. The approaches for the in-house code including a semi-empirical approach for the mean charge states, for inclusion of the gas density effect, and charge state distribution widths was revised. It enables sufficient qualitative and moderate quantitative agreement with the experimental values for nitrogen gas. The measured separation factors could be qualitatively reproduced by the in-house code. The investigations made clear that a general full established description of the inner processes within the gas-filled magnet is not sufficiently possible at the present state of research for a range of the required approaches. Finally, 60Fe AMS measurements were developed at the 10 MV AMS system. Therefore, a characterization of the system for iron measurements was conducted. The values for the present system are comparable to values given for larger AMS systems measuring 60}Fe. Thereby, for the first time successful AMS measurements using the gas-filled magnet at the Cologne 10 MV setup were conducted. Furthermore, for the first time in Cologne, successful AMS measurements of 60Fe reference sample sequences were achieved. Thereby, two sample sequence measurements of standard and background samples were conducted using different-sized detector entrance windows. For the smaller window a transmission from the measurement position of the stable reference isotope to the particle detector of 28.41 percent was achieved with a corrected background level of 60Fe/Fe=4.53(+3.85)(-1.46) E-15. With the larger window a transmission of 45.11 percent at a corrected background level of 60Fe/Fe=1.46(+0.47)(-0.30)E-14 was determined

Interactivity and thought

A shared tenet of embodied, embedded, situated and distributed cognition is that people make sense of things interactively. They run a simulation, they exchange words, often taking turns to change and steer the flow of interaction; they gesture, they handle or manipulate things, they write, sketch or model. Because the concept of interaction seems intuitive, and the phenomena so pervasive, researchers tend to use the term to do more work than they have time to explain. This symposium explores different ideas about the way interactivity is understood, and how it figures in thought processe

Synergistic activity of endochitinase and exochitinase from Trichoderma atroviride (T. harzianum) against the pathogenic fungus (Venturia inaequalis) in transgenic apple plants

Genes from the biocontrol fungus Trichoderma atroviride encoding the antifungal proteins endochitinase or exochitinase (N-acetyl-β-D-hexosaminidase) were inserted into ‘Marshall McIntosh' apple singly and in combination. The genes were driven by a modified CaMV35S promoter. The resulting plants were screened for resistance to Venturia inaequalis, the causal agent of apple scab, and for effects of enzyme expression on growth. Disease resistance was correlated with the level of expression of either enzyme when expressed alone but exochitinase was less effective than endochitinase. The level of expression of endochitinase was negatively correlated with plant growth while exochitinase had no consistent effect on this character. Plants expressing both enzymes simultaneously were more resistant than plants expressing either single enzyme at the same level; analyses indicated that the two enzymes acted synergistically to reduce disease. Selected lines, especially one expressing low levels of endochitinase activity and moderate levels of exochitinase activity, were highly resistant in growth chamber trials and had negligible reduction in vigor relative to control plants. We believe that this is the first report of resistance in plants induced by expression of an N-acetylhexosaminidase and is the first report of in planta synergy between an exochitinase and an endochitinas

EST contig-based SSR linkage maps for Malus × domestica cv Royal Gala and an apple scab resistant accession of M. sieversii , the progenitor species of domestic apple

Malus sieversii is a progenitor species of domestic apple M.×domestica. Using population "GMAL 4595” of 188 individuals derived from a cross of Royal Gala×PI 613988 (apple scab resistant, M. sieversii), 287 SSR (simple sequence repeats) loci were mapped. Of these SSRs, 80 are published anchors and 207 are newly developed EST (expressed sequence tag) contig-based SSRs, representing 1,630 Malus EST accessions in GenBank. Putative gene functions of these EST contigs are diverse, including regulating plant growth, development and response to environmental stresses. Among the 80 published SSRs, 18 are PI 613988 specific, 38 are common and 24 are Royal Gala specific. Out of the 207 newly developed EST contig-based SSRs, 79 are PI 613988 specific, 45 are common and 83 are Royal Gala specific. These results led to the construction of a M. sieversii map (1,387.0cM) of 180 SSR markers and a Royal Gala map (1,283.4cM) of 190 SSR markers. Mapping of scab resistance was independently conducted in two subsets of population "GMAL 4595” that were inoculated with Ventura inaequalis races (1) and (2), respectively. In combination with the two major resistance reactions Chl (chlorotic lesions) and SN (stellate necrosis) to each race, four subsets of resistance data, i.e., Chl/race (1), SN/race (1), Chl/race (2) and SN/race (2), were constituted and analyzed, leading to four resistance loci mapped to the linkage group 2 of PI 613988; SNR1 (stellate necrosis resistance to race (1)) and SNR2 are tightly linked in a region of known scab resistance genes, and ChlR1 (Chlorotic lesion resistance to race (1)) and ChlR2 are also linked tightly but in a region without known scab resistance genes. The utility of the two linkage maps, the new EST contig-based markers and M. sieversii as sources of apple scab resistance are discusse

Healthy babies through infant-centered feeding protocol: an intervention targeting early childhood obesity in vulnerable populations

<p>Abstract</p> <p>Background</p> <p>Poor feeding practices during infancy contribute to obesity risk. As infants transition from human milk and/or formula-based diets to solid foods, these practices interfere with infant feeding self-regulation and healthy growth patterns. Compared with other socioeconomic groups, lower-income mothers are more likely to experience difficulty feeding their infants. This may include misinterpreting feeding cues and using less-than-optimal feeding styles and practices, such as pressuring infants during mealtimes and prematurely introducing solid food and sweetened beverages. The Healthy Babies trial aims to determine the efficacy of a community-based randomized controlled trial of an in-home intervention with economically and educationally disadvantaged mother-infant dyads. The educational intervention is being conducted during the infant's first 6 months of life to promote healthy transition to solids during their first year and is based on the theory of planned behavior.</p> <p>Methods/Design</p> <p>We will describe our study protocol for a multisite randomized control trial being conducted in Colorado and Michigan with an anticipated sample of 372 economically and educationally disadvantaged African American, Hispanic, and Caucasian mothers with infants. Participants are being recruited by county community agency staff. Participants are randomly assigned to the intervention or the control group. The intervention consists of six in-home visits by a trained paraprofessional instructor followed by three reinforcement telephone contacts when the baby is 6, 8, and 10 months old. Main maternal outcomes include a) maternal responsiveness, b) feeding style, and c) feeding practices. Main infant outcome is infant growth pattern. All measures occur at baseline and when the infant is 6 and 12 months old.</p> <p>Discussion</p> <p>If this project is successful, the expected outcomes will address whether the home-based early nutrition education intervention is effective in helping mothers develop healthy infant feeding practices that contribute to improving infant health and development and reducing the risk of early-onset childhood obesity.</p> <p>Trial Registration</p> <p>Current Controlled Trials <a href="http://www.anzctr.org.au/ACTRN126100000415000.aspx">ACTRN126100000415000</a></p

Alterations in amino acid status in cats with feline dysautonomia

Feline dysautonomia (FD) is a multiple system neuropathy of unknown aetiology. An apparently identical disease occurs in horses (equine grass sickness, EGS), dogs, rabbits, hares, sheep, alpacas and llamas. Horses with acute EGS have a marked reduction in plasma concentrations of the sulphur amino acids (SAA) cyst(e)ine and methionine, which may reflect exposure to a neurotoxic xenobiotic. The aim of this study was to determine whether FD cats have alterations in amino acid profiles similar to those of EGS horses. Amino acids were quantified in plasma/serum from 14 FD cats, 5 healthy in-contact cats which shared housing and diet with the FD cats, and 6 healthy control cats which were housed separately from FD cats and which received a different diet. The adequacy of amino acids in the cats’ diet was assessed by determining the amino acid content of tinned and dry pelleted foods collected immediately after occurrences of FD. Compared with controls, FD cats had increased concentrations of many essential amino acids, with the exception of methionine which was significantly reduced, and reductions in most non-essential amino acids. In-contact cats also had inadequate methionine status. Artefactual loss of cysteine during analysis precluded assessment of the cyst(e)ine status. Food analysis indicated that the low methionine status was unlikely to be attributable to dietary inadequacy of methionine or cystine. Multi-mycotoxin screening identified low concentrations of several mycotoxins in dry food from all 3 premises. While this indicates fungal contamination of the food, none of these mycotoxins appears to induce the specific clinico-pathologic features which characterise FD and equivalent multiple system neuropathies in other species. Instead, we hypothesise that ingestion of another, as yet unidentified, dietary neurotoxic mycotoxin or xenobiotic, may cause both the characteristic disease pathology and the plasma SAA depletion

The Genome and Methylome of a Beetle with Complex Social Behavior,Nicrophorus vespilloides(Coleoptera: Silphidae)

Testing for conserved and novelmechanisms underlying phenotypic evolution requires a diversity of genomes available for comparisonspanning multiple independent lineages. For example, complex social behavior in insects has been investigated primarily witheusocial lineages, nearly all of which are Hymenoptera. If conserved genomic influences on sociality do exist, we need data from awider range of taxa that also vary in their levels of sociality. Here,we present the assembled and annotated genome of the subsocialbeetle Nicrophorus vespilloides, a species long used to investigate evolutionary questions of complex social behavior. We used thisgenome to address two questions. First, do aspects of life history, such as using a carcass to breed, predict overlap in gene modelsmore strongly than phylogeny? We found that the overlap in gene models was similar between N. vespilloides and all other insectgroups regardless of life history. Second, like other insects with highly developed social behavior but unlike other beetles, doesN. vespilloides have DNA methylation?We found strong evidence for an active DNA methylation system. The distribution of methylationwassimilar to other insects with exons having themostmethylatedCpGs. Methylation status appears highly conserved; 85%of themethylated genes in N. vespilloides are alsomethylated in the hymentopteran Nasonia vitripennis. The addition of this genomeadds a coleopteran resource to answer questions about the evolution and mechanistic basis of sociality and to address questionsabout the potential role of methylation in social behavior

A multimodal cell census and atlas of the mammalian primary motor cortex

ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties