1,416 research outputs found
Systems theory training as a context for healing : an autoethnography
The mini-dissertation explains how systems theory provided a healing context
for me in my training as a clinical psychologist over two years. The
emergence of my authentic voice is narrated in an autoethnography (five act
drama) about what happened. The main theoretical bases for the dissertation
are – constructivism to understand the learning and teaching I experienced;
learning as a collaborative endeavour and the emergence of my authentic
voice with help from more skilled others. Systems theory informs the entire
study at every theoretical level. Bowen’s family therapy theory is significant
for the differentiation of the self and his I-position is equated with the
emergence of an authentic voice. Myth, epic narratives, the hero’s journey
amplify my interpretation of the differentiation of self. The raw data for the
qualitative research were observations, interviews, creative writing, photocollage,
a collection of readings, songs and dialogues. The themes emerging
from the autoethnography were about obstructions because of the
authoritarian nature of my upbringing, life and work. These themes lessened
in force in clinical training until my authentic voice emerged in relation to self
and as a clinical psychologist. A recommendation from the dissertation is that
autoethnography provides a good vehicle for reflection and intense interior
scrutiny needed to become a practising clinical psychologist; the
autoethnographical exercise could be used by training clinical psychologists
more extensively on their journey to maturity.PsychologyM.A. (Clinical Psychology
Discovery of Sexual Dimorphisms in Metabolic and Genetic Biomarkers
Metabolomic profiling and the integration of whole-genome genetic association data has proven to be a powerful tool to comprehensively explore gene regulatory networks and to investigate the effects of genetic variation at the molecular level. Serum metabolite concentrations allow a direct readout of biological processes, and association of specific metabolomic signatures with complex diseases such as Alzheimer's disease and cardiovascular and metabolic disorders has been shown. There are well-known correlations between sex and the incidence, prevalence, age of onset, symptoms, and severity of a disease, as well as the reaction to drugs. However, most of the studies published so far did not consider the role of sexual dimorphism and did not analyse their data stratified by gender. This study investigated sex-specific differences of serum metabolite concentrations and their underlying genetic determination. For discovery and replication we used more than 3,300 independent individuals from KORA F3 and F4 with metabolite measurements of 131 metabolites, including amino acids, phosphatidylcholines, sphingomyelins, acylcarnitines, and C6-sugars. A linear regression approach revealed significant concentration differences between males and females for 102 out of 131 metabolites (p-values<3.8 x 10(-4); Bonferroni-corrected threshold). Sex-specific genome-wide association studies (GWAS) showed genome-wide significant differences in beta-estimates for SNPs in the CPS1 locus (carbamoyl-phosphate synthase 1, significance level: p<3.8 x 10(-10); Bonferroni-corrected threshold) for glycine. We showed that the metabolite profiles of males and females are significantly different and, furthermore, that specific genetic variants in metabolism-related genes depict sexual dimorphism. Our study provides new important insights into sex-specific differences of cell regulatory processes and underscores that studies should consider sex-specific effects in design and interpretation
Photometric variability of the T Tauri star TW Hya on time scales of hours to years
MOST (Microvariability & Oscillations of STars) and ASAS (All Sky Automated
Survey) observations have been used to characterize photometric variability of
TW Hya on time scales from a fraction of a day to 7.5 weeks and from a few days
to 8 years, respectively. The two data sets have very different uncertainties
and temporal coverage properties and cannot be directly combined, nevertheless,
they suggests a global variability spectrum with "flicker noise" properties,
i.e. with amplitudes a ~ 1/sqrt(f), over >4 decades in frequency, in the range
f = 0.0003 to 10 cycles per day (c/d). A 3.7 d period is clearly present in the
continuous 11 day, 0.07 d time resolution, observations by MOST in 2007.
Brightness extrema coincide with zero-velocity crossings in periodic (3.56 d)
radial velocity variability detected in contemporaneous spectroscopic
observations of Setiawan et al. (2008) and interpreted as caused by a planet.
The 3.56/3.7 d periodicity was entirely absent in the second, four times longer
MOST run in 2008, casting doubt on the planetary explanation. Instead, a
spectrum of unstable single periods within the range of 2 - 9 days was
observed; the tendency of the periods to progressively shorten was well traced
using the wavelet analysis. The evolving periodicities and the overall
flicker-noise characteristics of the TW Hya variability suggest a combination
of several mechanisms, with the dominant ones probably related to the accretion
processes from the disk around the star.Comment: MNRAS submitte
Discovery of Sexual Dimorphisms in Metabolic and Genetic Biomarkers
Metabolomic profiling and the integration of whole-genome genetic association data has proven to be a powerful tool to comprehensively explore gene regulatory networks and to investigate the effects of genetic variation at the molecular level. Serum metabolite concentrations allow a direct readout of biological processes, and association of specific metabolomic signatures with complex diseases such as Alzheimer's disease and cardiovascular and metabolic disorders has been shown. There are well-known correlations between sex and the incidence, prevalence, age of onset, symptoms, and severity of a disease, as well as the reaction to drugs. However, most of the studies published so far did not consider the role of sexual dimorphism and did not analyse their data stratified by gender. This study investigated sex-specific differences of serum metabolite concentrations and their underlying genetic determination. For discovery and replication we used more than 3,300 independent individuals from KORA F3 and F4 with metabolite measurements of 131 metabolites, including amino acids, phosphatidylcholines, sphingomyelins, acylcarnitines, and C6-sugars. A linear regression approach revealed significant concentration differences between males and females for 102 out of 131 metabolites (p-values<3.8 x 10(-4); Bonferroni-corrected threshold). Sex-specific genome-wide association studies (GWAS) showed genome-wide significant differences in beta-estimates for SNPs in the CPS1 locus (carbamoyl-phosphate synthase 1, significance level: p<3.8 x 10(-10); Bonferroni-corrected threshold) for glycine. We showed that the metabolite profiles of males and females are significantly different and, furthermore, that specific genetic variants in metabolism-related genes depict sexual dimorphism. Our study provides new important insights into sex-specific differences of cell regulatory processes and underscores that studies should consider sex-specific effects in design and interpretation
Effects of smoking and smoking cessation on human serum metabolite profile: results from the KORA cohort study
Background: Metabolomics helps to identify links between environmental exposures and intermediate biomarkers of disturbed pathways. We previously reported variations in phosphatidylcholines in male smokers compared with non-smokers in a cross-sectional pilot study with a small sample size, but knowledge of the reversibility of smoking effects on metabolite profiles is limited. Here, we extend our metabolomics study with a large prospective study including female smokers and quitters. Methods: Using targeted metabolomics approach, we quantified 140 metabolite concentrations for 1,241 fasting serum samples in the population-based Cooperative Health Research in the Region of Augsburg (KORA) human cohort at two time points: baseline survey conducted between 1999 and 2001 and follow-up after seven years. Metabolite profiles were compared among groups of current smokers, former smokers and never smokers, and were further assessed for their reversibility after smoking cessation. Changes in metabolite concentrations from baseline to the follow-up were investigated in a longitudinal analysis comparing current smokers, never smokers and smoking quitters, who were current smokers at baseline but former smokers by the time of follow-up. In addition, we constructed protein-metabolite networks with smoking-related genes and metabolites. Results: We identified 21 smoking-related metabolites in the baseline investigation (18 in men and six in women, with three overlaps) enriched in amino acid and lipid pathways, which were significantly different between current smokers and never smokers. Moreover, 19 out of the 21 metabolites were found to be reversible in former smokers. In the follow-up study, 13 reversible metabolites in men were measured, of which 10 were confirmed to be reversible in male quitters. Protein-metabolite networks are proposed to explain the consistent reversibility of smoking effects on metabolites. Conclusions: We showed that smoking-related changes in human serum metabolites are reversible after smoking cessation, consistent with the known cardiovascular risk reduction. The metabolites identified may serve as potential biomarkers to evaluate the status of smoking cessation and characterize smoking-related diseases
Synchronous and proportional deglacial changes in Atlantic meridional overturning and northeast Brazilian precipitation
Changes in heat transport associated with fluctuations in the strength of the Atlantic meridional overturning circulation (AMOC) are widely considered to affect the position of the Intertropical Convergence Zone (ITCZ), but the temporal immediacy of this teleconnection has to date not been resolved. Based on a high-resolution marine sediment sequence over the last deglaciation, we provide evidence for a synchronous and near-linear link between changes in the Atlantic interhemispheric sea surface temperature difference and continental precipitation over northeast Brazil. The tight coupling between AMOC strength, sea surface temperature difference, and precipitation changes over northeast Brazil unambiguously points to a rapid and proportional adjustment of the ITCZ location to past changes in the Atlantic meridional heat transport
Human serum metabolic profiles are age dependent
Understanding the complexity of aging is of utmost importance. This can now be addressed by the novel and powerful approach of metabolomics. However, to date, only a few metabolic studies based on large samples are available. Here, we provide novel and specific information on age-related metabolite concentration changes in human homeostasis. We report results from two population-based studies: the KORA F4 study from Germany as a discovery cohort, with 1038 female and 1124 male participants (32–81 years), and the TwinsUK study as replication, with 724 female participants. Targeted metabolomics of fasting serum samples quantified 131 metabolites by FIA-MS/MS. Among these, 71/34 metabolites were significantly associated with age in women/men (BMI adjusted). We further identified a set of 13 independent metabolites in women (with P values ranging from 4.6 × 10−04 to 7.8 × 10−42, αcorr = 0.004). Eleven of these 13 metabolites were replicated in the TwinsUK study, including seven metabolite concentrations that increased with age (C0, C10:1, C12:1, C18:1, SM C16:1, SM C18:1, and PC aa C28:1), while histidine decreased. These results indicate that metabolic profiles are age dependent and might reflect different aging processes, such as incomplete mitochondrial fatty acid oxidation. The use of metabolomics will increase our understanding of aging networks and may lead to discoveries that help enhance healthy aging
The Disk Population of the Taurus Star-Forming Region
We have analyzed nearly all images of the Taurus star-forming region at
3.6-24um that were obtained during the cryogenic mission of the Spitzer Space
Telescope (46 deg^2) and have measured photometry for all known members of the
region that are within these data, corresponding to 348 sources. We have
classified the members of Taurus according to whether they show evidence of
disks and envelopes (classes I, II, and III). The disk fraction in Taurus is
75% for solar-mass stars and declines to 45% for low-mass stars and brown
dwarfs (0.01-0.3 M_sun). This dependence on stellar mass is similar to that
measured for Cha I, although the disk fraction in Taurus is slightly higher
overall, probably because of its younger age (1 vs. 2-3 Myr). In comparison,
the disk fraction for solar-mass stars is much lower (20%) in IC 348 and Sigma
Ori, which are denser than Taurus and Cha I and are roughly coeval with the
latter. These data indicate that disk lifetimes for solar-mass stars are longer
in regions that have lower stellar densities. Through an analysis of multiple
epochs of photometry that are available for ~200 Taurus members, we find that
stars with disks exhibit significantly greater mid-IR variability than diskless
stars. Finally, we have used our data in Taurus to refine the criteria for
primordial, evolved, and transitional disks. The number ratio of evolved and
transitional disks to primordial disks in Taurus is 15/98 for K5-M5, indicating
a timescale of 0.15 x tau(primordial)=0.45 Myr for the clearing of the inner
regions of optically thick disks. After applying the same criteria to older
clusters (2-10 Myr), we find that the proportions of evolved and transitional
disks in those populations are consistent with the measurements in Taurus when
their star formation histories are properly taken into account. ERRATUM: In
Table 7, we inadvertently omitted the spectral type bins in which class II
sources were placed in Table 8 based on their bolometric luminosities (applies
only to stars that lack spectroscopic classifications). The bins were K6-M3.5
for FT Tau, DK Tau B, and IRAS 04370+2559, M3.5-M6 for IRAS 04200+2759, IT Tau
B, and ITG 1, and M6-M8 for IRAS 04325+2402 C. In addition, the values of
K_s-[3.6] in Table 13 and Figure 26 for spectral types of M4-M9 are incorrect.
We present corrected versions of Table 13 and Figure 26.Comment: revised version with Erratum (in press
Analysis of MOST light curves of five young stars in Taurus-Auriga and Lupus 3 Star Forming Regions
Continuous photometric observations of five young stars obtained by the MOST
satellite in 2009 and 2010 in the Taurus and Lupus star formation regions are
presented. Using light curve modelling under the assumption of internal
invariability of spots, we obtained small values of the solar-type
differential-rotation parameter (k=0.0005-0.009) for three spotted weak-line T
Tau stars, V410 Tau, V987 Tau and Lupus 3-14; for another spotted WTTS, Lupus
3-48, the data are consistent with a rigidly rotating surface (k=0). Three
flares of similar rise (4 min 30 sec) and decay (1 h 45 min) times were
detected in the light curve of Lupus 3-14. The brightness of the classical T
Tau star RY Tau continuously decreased over 3 weeks of its observations with a
variable modulation not showing any obvious periodic signal.Comment: Accepted by MNRA
Genetics Meets Metabolomics: A Genome-Wide Association Study of Metabolite Profiles in Human Serum
The rapidly evolving field of metabolomics aims at a comprehensive measurement of ideally all endogenous metabolites in a cell or body fluid. It thereby provides a functional readout of the physiological state of the human body. Genetic variants that associate with changes in the homeostasis of key lipids, carbohydrates, or amino acids are not only expected to display much larger effect sizes due to their direct involvement in metabolite conversion modification, but should also provide access to the biochemical context of such variations, in particular when enzyme coding genes are concerned. To test this hypothesis, we conducted what is, to the best of our knowledge, the first GWA study with metabolomics based on the quantitative measurement of 363 metabolites in serum of 284 male participants of the KORA study. We found associations of frequent single nucleotide polymorphisms (SNPs) with considerable differences in the metabolic homeostasis of the human body, explaining up to 12% of the observed variance. Using ratios of certain metabolite concentrations as a proxy for enzymatic activity, up to 28% of the variance can be explained (p-values 10−16 to 10−21). We identified four genetic variants in genes coding for enzymes (FADS1, LIPC, SCAD, MCAD) where the corresponding metabolic phenotype (metabotype) clearly matches the biochemical pathways in which these enzymes are active. Our results suggest that common genetic polymorphisms induce major differentiations in the metabolic make-up of the human population. This may lead to a novel approach to personalized health care based on a combination of genotyping and metabolic characterization. These genetically determined metabotypes may subscribe the risk for a certain medical phenotype, the response to a given drug treatment, or the reaction to a nutritional intervention or environmental challenge
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