1. |
-
- 2019
-
Journal article (peer-reviewed)
|
|
2. |
- Barrado, David, et al.
(author)
-
15NH3 in the atmosphere of a cool brown dwarf
- 2023
-
In: Nature. - 0028-0836 .- 1476-4687. ; 624:7991, s. 263-266
-
Journal article (peer-reviewed)abstract
- Brown dwarfs serve as ideal laboratories for studying the atmospheres of giant exoplanets on wide orbits, as the governing physical and chemical processes within them are nearly identical. Understanding the formation of gas-giant planets is challenging, often involving the endeavour to link atmospheric abundance ratios, such as the carbon-to-oxygen (C/O) ratio, to formation scenarios. However, the complexity of planet formation requires further tracers, as the unambiguous interpretation of the measured C/O ratio is fraught with complexity. Isotope ratios, such as deuterium to hydrogen and 14N/15N, offer a promising avenue to gain further insight into this formation process, mirroring their use within the Solar System. For exoplanets, only a handful of constraints on 12C/13C exist, pointing to the accretion of 13C-rich ice from beyond the CO iceline of the disks. Here we report on the mid-infrared detection of the 14NH3 and 15NH3 isotopologues in the atmosphere of a cool brown dwarf with an effective temperature of 380 K in a spectrum taken with the Mid-Infrared Instrument (MIRI) of JWST. As expected, our results reveal a 14N/15N value consistent with star-like formation by gravitational collapse, demonstrating that this ratio can be accurately constrained. Because young stars and their planets should be more strongly enriched in the 15N isotope, we expect that 15NH3 will be detectable in several cold, wide-separation exoplanets.
|
|
3. |
- Dyrek, Achrène, et al.
(author)
-
SO2, silicate clouds, but no CH4 detected in a warm Neptune
- 2024
-
In: Nature. - 0028-0836 .- 1476-4687. ; 625, s. 51-54
-
Journal article (peer-reviewed)abstract
- WASP-107b is a warm (approximately 740 K) transiting planet with a Neptune-like mass of roughly 30.5 M⊕ and Jupiter-like radius of about 0.94 RJ (refs. 1,2), whose extended atmosphere is eroding3. Previous observations showed evidence for water vapour and a thick, high-altitude condensate layer in the atmosphere of WASP-107b (refs. 4,5). Recently, photochemically produced sulfur dioxide (SO2) was detected in the atmosphere of a hot (about 1,200 K) Saturn-mass planet from transmission spectroscopy near 4.05 μm (refs. 6,7), but for temperatures below about 1,000 K, sulfur is predicted to preferably form sulfur allotropes instead of SO2 (refs. 8,9,10). Here we report the 9σ detection of two fundamental vibration bands of SO2, at 7.35 μm and 8.69 μm, in the transmission spectrum of WASP-107b using the Mid-Infrared Instrument (MIRI) of JWST. This discovery establishes WASP-107b as the second irradiated exoplanet with confirmed photochemistry, extending the temperature range of exoplanets exhibiting detected photochemistry from about 1,200 K down to about 740 K. Furthermore, our spectral analysis reveals the presence of silicate clouds, which are strongly favoured (around 7σ) over simpler cloud set-ups. Furthermore, water is detected (around 12σ) but methane is not. These findings provide evidence of disequilibrium chemistry and indicate a dynamically active atmosphere with a super-solar metallicity.
|
|
4. |
- Franz, F, et al.
(author)
-
The Transcriptional Regulation of FOXO Genes in Thyrocytes.
- 2016
-
In: Hormone and Metabolic Research. - Stuttgart : Georg Thieme Verlag. - 0018-5043 .- 1439-4286. ; 48:9, s. 601-6
-
Journal article (peer-reviewed)abstract
- FOXO transcription factors are key regulators of DNA damage repair, proliferation and apoptosis in thyrocytes. Thyroid malignancies show impaired FOXO function. In this study, we investigated the transcriptional regulation of FOXO isoforms in thyroid epithelial cells. mRNA expression of FOXO isoforms (FOXO1, 3 and 4) was determined in FRTL-5 cells stimulated with different growth factors and H2O2. Furthermore, the impact of PI3K/AKT signalling on FOXO transcription was investigated in PI3K p110α mutant FRTL-5 cells and regulatory dependence of FOXO transcription on FOXO was studied in FRTL-5 cells with hFOXO3 overexpression. Finally, mRNA expression levels of FOXO isoforms were determined in human epithelial thyroid tumours. Growth factor deprivation induced transcription of FOXO1, 3 and 4, whereas insulin stimulation decreased FOXO1 and FOXO4 transcription in FRTL-5 cells. Inhibition of the PI3K/AKT cascade amplified FOXO1 and FOXO4 expression. In contrast, H2O2 and TSH did not influence FOXO transcription in thyrocytes. Overexpression of PI3K p110α inhibited FOXO3 and induced FOXO4 transcription. In human thyroid tumours, FOXO1 and FOXO3 mRNA levels were significantly downregulated in papillary thyroid carcinoma when compared to normal tissues. In contrast, follicular thyroid carcinomas showed significant upregulation of FOXO4 mRNA.In this paper, we demonstrate an influence of PI3K signalling on FOXO transcription in thyrocytes. Moreover, we show that thyroid cancers exhibit alterations in FOXO transcription besides the previously reported alterations in posttranslational FOXO3 regulation. These findings may add to the concept of targeting the PI3K pathway in advanced thyroid cancers.
|
|
5. |
- Gashi, Bersant, et al.
(author)
-
Investigations of Active Antenna Doherty Power Amplifier Modules Under Beam-Steering Mismatch
- 2018
-
In: IEEE Microwave and Wireless Components Letters. - 1558-1764 .- 1531-1309. ; 28:10, s. 930-932
-
Journal article (peer-reviewed)abstract
- This letter investigates the performance of a Doherty power amplifier (DPA) in an 8 x 1 active antenna transmitter module under an average voltage-standing-wave ratio of 4 : 1 induced by the array 1-D beam steering and mutual coupling. The GaN-based DPA and a 2 x 1 segment of the array are verified via measurements at the operating frequency of 3.5 GHz. The co-design and co-simulation of both the antenna array and the behavioral model of the DPA show that the inherent back-off efficiency benefit-when compared to traditionally used class-AB and -B amplifiers in base stations-can be maintained when restricting the beam-steering angle, in this case theta is an element of [-45 degrees, 45 degrees], and operational bandwidth of the combined system.
|
|
6. |
- Gimm, Oliver, et al.
(author)
-
Distinct expression of galectin-3 in pheochromocytomas.
- 2006
-
In: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1073, s. 571-7
-
Journal article (peer-reviewed)abstract
- Unless distant metastases or local invasion are present, the diagnosis of malignant pheochromocytoma is challenging. Hence, biological markers are sought after and we thought to examine galectin-3 in such a role. Four malignant and 24 benign (10 sporadic, 14 hereditary) pheochromocytomas were analyzed for the expression of galectin-3. One malignant pheochromocytoma with distant metastases showed strong and one malignant undifferentiated pheochromocytoma with local invasion showed partly strong cytoplasmic staining. Nine of 10 sporadic and all hereditary benign pheochromocytomas had absent/weak staining. One benign sporadic pheochromocytoma had moderate cytoplasmic staining. The distinct expression in various types of pheochromocytomas is intriguing and requires further investigation.
|
|
7. |
- Gimm, Oliver, et al.
(author)
-
Prognostic significance of disseminated tumor cells in the connective tissue of patients with medullary thyroid carcinoma.
- 2006
-
In: World Journal of Surgery. - : Springer Science and Business Media LLC. - 0364-2313 .- 1432-2323. ; 30:5, s. 847-52
-
Journal article (peer-reviewed)abstract
- INTRODUCTION: Disseminated tumor cells in the connective tissue (CT-DTCs) do not have any connection to a primary tumor or the lymph nodes. They are identified quite often in patients with medullary thyroid carcinoma (MTC), but nothing is known regarding their prognostic significance.METHODS: Among 450 patients with MTC, 69 (15%) were identified as having CT-DTCs. A case-control group of patients without CT-DTCs was selected. The two groups were matched concerning TNM classification, age, heredity, and sex. Because many patients with CT-DTCs had extrathyroidal tumor extension (pT4 category), distant metastases (M1 category), or both, only 35 matched pairs could be identified. The TNM classification in both groups was as follows: pT1, n = 8; pT2, n = 15; pT3, n = 4; pT4, n = 8; pN0, n = 4; pN1, n = 31; M0, n = 30; M1, n = 5. The mean age was 46.8 +/- 17.0 years in the CT-DTC group and 44.4 +/- 15.0 years in the case-control group (NS).RESULTS: In both groups, 23 patients had sporadic MTC, and 12 patients had hereditary MTC. Neither mean basal preoperative nor postoperative calcitonin levels differed significantly between the two groups. In contrast, none of the patients with CT-DTCs was biochemically cured (normal calcitonin level after pentagastrin stimulation) compared to eight patients without CT-DTCs (P < 0.005). The two groups did not differ concerning other parameters (basal calcitonin level > 3000 pg/ml, more than 10 lymph node metastases, more than two involved locoregional lymph node compartments, mediastinal lymph node metastases) that have been reported to correlate with the lack of or almost (< 10%) lack of biochemical cure.CONCLUSIONS: In patients with MTC, disseminated tumor cells in the connective tissue correlate with advanced tumor stages and appear to be of prognostic significance.
|
|
8. |
- Janson, Markus, et al.
(author)
-
Occulter to earth : prospects for studying earth-like planets with the E-ELT and a space-based occulter
- 2022
-
In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 54:2-3, s. 1223-1236
-
Journal article (peer-reviewed)abstract
- Direct detection and characterization of Earth-like planets around Sun-like stars is a core task for evaluating the prevalence of habitability and life in the Universe. Here, we discuss a promising option for achieving this goal, which is based on placing an occulter in orbit and having it project its shadow onto the E-ELT at the surface of Earth, thus providing a sufficient contrast for imaging and taking spectra of Earth-like planets in the habitable zones of Sun-like stars. Doing so at a sensible fuel budget will require tailored orbits, an occulter with a high area-to-mass ratio, and appropriate instrumentation at the E-ELT. In this White Paper, submitted in response to the ESA Voyage 2050 Call, we outline the fundamental aspects of the concept, and the most important technical developments that will be required to develop a full mission.
|
|
9. |
- Karger, Stefan, et al.
(author)
-
Distinct pattern of oxidative DNA damage and DNA repair in follicular thyroid tumours.
- 2012
-
In: Journal of molecular endocrinology. - 1479-6813. ; 48:3, s. 193-202
-
Journal article (peer-reviewed)abstract
- Increased oxidative stress has been linked to thyroid carcinogenesis. In this paper, we investigate whether oxidative DNA damage and DNA repair differ in follicular adenoma (FA) and follicular thyroid carcinoma (FTC). 7,8-Dihydro-8-oxoguanine (8-OxoG) formation was analysed by immunohistochemistry in 46 FAs, 52 FTCs and 18 normal thyroid tissues (NTs). mRNA expression of DNA repair genes OGG1, Mut Y homologue (MUTYH) and endonuclease III (NTHL1) was analysed by real-time PCR in 19 FAs, 25 FTCs and 19 NTs. Induction and repair of oxidative DNA damage were studied in rat FRTL-5 cells after u.v. irradiation. Moreover, activation of DNA damage checkpoints (ataxia telangiectasia mutated (ATM) and H2A histone family, member X (H2AFX (H2AFX))) and proliferation index (MIB-1) were quantified in 28 non-oxyphilic and 24 oxyphilic FTCs. Increased nuclear and cytosolic 8-OxoG formation was detected in FTC compared with follicular adenoma, whereby cytosolic 8-OxoG formation was found to reflect RNA oxidation. Significant downregulation of DNA repair enzymes was detected in FTC compared with FA. In vitro experiments mirrored the findings in FTC with oxidative stress-induced DNA checkpoint activation and downregulation of OGG1, MUTYH and NTHL1 in FRTL-5 cells, an effect that, however, was reversible after 24 h. Further analysis of FTC variants showed decreased oxidative DNA damage, sustained checkpoint activation and decreased proliferation in oxyphilic vs non-oxyphilic FTC. Our data suggest a pathophysiological scenario of accumulating unrepaired DNA/RNA damage in FTC vs counterbalanced DNA/RNA damage and repair in FA. Furthermore, this study provides the first evidence for differences in oxidative stress defence in FTC variants with possible implications for therapeutic response and prognostic outcome.
|
|
10. |
- Karger, Stefan, et al.
(author)
-
FOXO3a : a novel player in thyroid carcinogenesis?
- 2009
-
In: Endocrine-Related Cancer. - 1351-0088 .- 1479-6821. ; 16:1, s. 189-99
-
Journal article (peer-reviewed)abstract
- The forkhead box transcription factor FOXO3a has recently been identified as central mediator of the cellular response to oxidative stress inducing cell cycle arrest or apoptosis. The aim of our study was to investigate the regulation of FOXO3a in the thyroid and to determine whether alterations in FOXO3a activity occur in thyroid carcinogenesis. In vitro, we demonstrate that FOXO3a activity is negatively regulated by the PI3K/Akt cascade promoting increased phosphorylation and cytoplasmatic accumulation of FOXO3a with decreased transcription of the target genes p27kip (CDKN1B) and Bim (BCL2L11), but increased expression of GADD45A. By contrast, we show that H(2)O(2) exposure activates FOXO3a in thyrocytes with JNK (MAPK8)-mediated nuclear accumulation of FOXO3a and increased expression of the cell cycle arrest genes p27kip and GADD45A. In vivo, we observed a marked cytoplasmatic accumulation of FOXO3a in differentiated thyroid cancers versus an exclusive nuclear accumulation in follicular adenoma and normal thyroid tissue. Moreover, this cytosolic accumulation of FOXO3a correlated with an increased phospho-Akt expression in thyroid malignancies and was accompanied by decreased expression of the FOXO targets p27kip and Bim and an increase in GADD45A mRNA expression in the thyroid cancers. Our data suggest FOXO3a as a novel player of cellular stress response in the thyroid, mediating the thyrocyte's fate either to survive or to undergo apoptosis. Furthermore, PI3K-dependent FOXO3a inactivation may be a novel pathomechanism for the escape from apoptosis in thyroid cancer cells, in particular in follicular thyroid carcinoma.
|
|
11. |
- Krause, Kerstin, et al.
(author)
-
Characterisation of DEHAL1 expression in thyroid pathologies.
- 2007
-
In: European Journal of Endocrinology. - 0804-4643 .- 1479-683X. ; 156:3, s. 295-301
-
Journal article (peer-reviewed)abstract
- UNLABELLED: Iodotyrosine dehalogenase 1 (DEHAL1) is a transmembrane protein involved in the recycling of iodide in the human thyroid. The aim of the present study was (I) to investigate whether DEHAL1 expression is different in differentially functioning thyroid pathologies and (II) to evaluate DEHAL1 as a possible marker of thyroid cell differentiation.DESIGN AND METHODS: Real-time PCR for DEHAL1 and its isoform DEHAL1B was performed in a series of 105 thyroid specimens, including toxic thyroid nodules (TTN), Graves' disease (GD) thyroids, benign cold thyroid nodules (CTN), normal thyroid tissues and thyroid cancers (follicular thyroid carcinomas (FTC), papillary thyroid carcinomas (PTC), partially differentiated thyroid cancers (PDTC) and anaplastic thyroid carcinomas (ATC)). In addition, DEHAL1 protein expression was studied by immunohistochemistry in 163 benign and malignant thyroid pathologies and normal thyroids.RESULTS: (I) The highest DEHAL1 mRNA levels were found in GD thyroids, while downregulation of DEHAL1 and DEHAL1B mRNA occurred in PTC and ATC (P<0.001 and <0.05 respectively); (II) DEHAL1 protein was overexpressed in TTNs and GD thyroids with predominant apical staining in all samples; (III) a weaker and patchy staining pattern was found in CTNs and normal thyroids; (IV) in differentiated thyroid cancers (FTC and PTC), a diffuse cytoplasmic DEHAL1 expression was found; and (V) in PDTC and ATC, DEHAL1 expression was faint or absent.CONCLUSION: Upregulation of DEHAL1 protein expression and sublocalisation of DEHAL1 at the apical cell pole in TTNs and GD thyroids is consistent with increased thyroid hormone turnover during thyrotoxicosis. Diffuse cytoplasmatic localisation or downregulation of DEHAL1 expression in thyroid cancers suggests alteration or loss of DEHAL1 function during thyroid cell dedifferentiation.
|
|
12. |
- Krause, Kerstin, et al.
(author)
-
Dissecting molecular events in thyroid neoplasia provides evidence for distinct evolution of follicular thyroid adenoma and carcinoma.
- 2011
-
In: American Journal of Pathology. - : Elsevier BV. - 0002-9440 .- 1525-2191. ; 179:6, s. 3066-74
-
Journal article (peer-reviewed)abstract
- Benign hypofunctional cold thyroid nodules (CTNs) are a frequent scintiscan finding and need to be distinguished from thyroid carcinomas. The origin of CTNs with follicular morphologic features is unresolved. The DNA damage response might act as a physiologic barrier, inhibiting the progression of preneoplastic lesions to neoplasia. We investigated the following in hypofunctional follicular adenoma (FA) and follicular thyroid cancer (FTC): i) the mutation rate of frequently activated oncogenes, ii) the activation of DNA damage response checkpoints, and iii) the differential proteomic pattern between FA and FTC. Both FTC and FA, which did not harbor RAS, phosphoinositide-3-kinase, or PAX/peroxisome proliferator activated receptor-γ mutations, express various proteins in common and others that are more distinctly expressed in FTC rather than in FA or normal thyroid tissue. This finding is in line with the finding of constitutive DNA damage checkpoint activation (p-Chk2, γ-H2AX) and evidence for replicative stress causing genomic instability (increased cyclin E, retinoblastoma, or E2F1 mRNA expression) in FTC but not FA. We discuss the findings of the increased expression of translationally controlled tumor protein, phosphatase 2A inhibitor, and DJ-1 in FTC compared with FA identified by proteomics and their potential implication in follicular thyroid carcinogenesis. Our present findings argue for the definition of FA as a truly benign entity and against progressive development of FA to FTC.
|
|
13. |
- Krause, Kerstin, et al.
(author)
-
Evidence for a role of the amyloid precursor protein in thyroid carcinogenesis.
- 2008
-
In: The Journal of endocrinology. - 1479-6805. ; 198:2, s. 291-9
-
Journal article (peer-reviewed)abstract
- We have recently found an increased expression of amyloid precursor protein (APP) in cold thyroid nodules that are difficult to classify as a truly benign thyroid neoplasm or a lesion with the potential for further dedifferentiation. Since differences in APP activity have been found in other human cancers, we asked whether thyroid carcinogenesis might be associated with an altered APP expression and function. APP regulation was studied in vitro in differentiated (FRTL-5) and dedifferentiated follicular thyroid carcinomas (FTC-133) thyroid cells after specific inhibition or activation of the cAMP-PKA, the PI3K/AKT or the protein kinase c (PKC) cascades. In vivo analysis of APP expression and downstream signalling was performed in benign and malignant thyroid tissues. We found that upregulation of APP expression and sAPP secretion is induced by TSH in differentiated thyroid cells and by insulin in thyroid cancer cells. PKC is a strong activator of APP cleavage and in FTC-133 confers prolonged release of the APP ectodomain. FTC-133 but not FRTL-5 cells show a prominent cell surface expression of the APP ectodomain, which has been suggested to function as an autocrine growth factor. Thyroid cancers are characterized by APP upregulation, increased membrane targeting of the APP ectodomain and significantly increased mRNA levels of the APP scaffold proteins JIP1, ShcA and Fe65.
|
|
14. |
- Krause, Kerstin, et al.
(author)
-
TFF3-based candidate gene discrimination of benign and malignant thyroid tumors in a region with borderline iodine deficiency.
- 2008
-
In: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 93:4, s. 1390-3
-
Journal article (peer-reviewed)abstract
- BACKGROUND: With the advent of microarray technology, increasing numbers of marker genes are proposed to distinguish benign and malignant thyroid lesions. However, most markers await confirmation through independent studies. In this paper, we re-evaluate the diagnostic potential of 10 proposed candidate genes in benign and malignant thyroid pathologies in a region with borderline iodine deficiency.METHODS: Quantitative real-time PCR was performed for CCND2, PLAB, PCSK2, HGD1, TFF3, B4GALT, LGALS3, ETS1, ADM3, and TG in 150 thyroid specimens, including 52 benign thyroid nodules (28 follicular adenoma and 24 adenomatous nodules), 52 corresponding normal thyroid tissues, 20 follicular carcinomas, 20 papillary carcinomas, and six undifferentiated carcinomas.RESULTS: On a single-gene basis, significant differences in mRNA expression were found for TFF3, PLAB, and ADM3 in benign thyroid nodules and thyroid malignancy. Using two-marker gene sets, we identified 11 combinations, which allowed both a distinction of benign and malignant thyroid nodules and a discrimination of follicular adenoma and carcinoma. However, for cancer prediction, analysis of a minimum of six genes per sample was necessary and allowed correct prediction of a benign thyroid lesion and thyroid cancer with 94% accuracy in the most discriminative set (TFF3/PLAB/TG/ADM3/HGD1/LGALS3).CONCLUSION: We confirm the applicability of a number of recently proposed marker genes for the distinction of benign and malignant thyroid tumor and suggest that their diagnostic usefulness is independent of the iodide supply. We propose that the most discriminative marker set identified in our validation study together with marker combinations proposed by other investigators should now be evaluated in multicenter trials.
|
|
15. |
- Quanz, Sascha P., et al.
(author)
-
Atmospheric characterization of terrestrial exoplanets in the mid-infrared : biosignatures, habitability, and diversity
- 2022
-
In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 54:2-3, s. 1197-1221
-
Journal article (peer-reviewed)abstract
- Exoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper, submitted to ESA in response to the Voyage 2050 Call, we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the mid-infrared wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large mid-infrared exoplanet mission within the scope of the “Voyage 2050” long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large mid-infrared exoplanet imaging mission will be needed to help answer one of humankind’s most fundamental questions: “How unique is our Earth?”
|
|
16. |
- Radner, H, et al.
(author)
-
2017 EULAR recommendations for a core data set to support observational research and clinical care in rheumatoid arthritis
- 2018
-
In: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 77:4, s. 476-479
-
Journal article (peer-reviewed)abstract
- Personalised medicine, new discoveries and studies on rare exposures or outcomes require large samples that are increasingly difficult for any single investigator to obtain. Collaborative work is limited by heterogeneities, both what is being collected and how it is defined. To develop a core set for data collection in rheumatoid arthritis (RA) research which (1) allows harmonisation of data collection in future observational studies, (2) acts as a common data model against which existing databases can be mapped and (3) serves as a template for standardised data collection in routine clinical practice to support generation of research-quality data. A multistep, international multistakeholder consensus process was carried out involving voting via online surveys and two face-to-face meetings. A core set of 21 items (‘what to collect’) and their instruments (‘how to collect’) was agreed: age, gender, disease duration, diagnosis of RA, body mass index, smoking, swollen/tender joints, patient/evaluator global, pain, quality of life, function, composite scores, acute phase reactants, serology, structural damage, treatment and comorbidities. The core set should facilitate collaborative research, allow for comparisons across studies and harmonise future data from clinical practice via electronic medical record systems.
|
|
17. |
- Schweinsberg, Martin, et al.
(author)
-
Same data, different conclusions : Radical dispersion in empirical results when independent analysts operationalize and test the same hypothesis
- 2021
-
In: Organizational Behavior and Human Decision Processes. - : Elsevier BV. - 0749-5978 .- 1095-9920. ; 165, s. 228-249
-
Journal article (peer-reviewed)abstract
- In this crowdsourced initiative, independent analysts used the same dataset to test two hypotheses regarding the effects of scientists' gender and professional status on verbosity during group meetings. Not only the analytic approach but also the operationalizations of key variables were left unconstrained and up to individual analysts. For instance, analysts could choose to operationalize status as job title, institutional ranking, citation counts, or some combination. To maximize transparency regarding the process by which analytic choices are made, the analysts used a platform we developed called DataExplained to justify both preferred and rejected analytic paths in real time. Analyses lacking sufficient detail, reproducible code, or with statistical errors were excluded, resulting in 29 analyses in the final sample. Researchers reported radically different analyses and dispersed empirical outcomes, in a number of cases obtaining significant effects in opposite directions for the same research question. A Boba multiverse analysis demonstrates that decisions about how to operationalize variables explain variability in outcomes above and beyond statistical choices (e.g., covariates). Subjective researcher decisions play a critical role in driving the reported empirical results, underscoring the need for open data, systematic robustness checks, and transparency regarding both analytic paths taken and not taken. Implications for orga-nizations and leaders, whose decision making relies in part on scientific findings, consulting reports, and internal analyses by data scientists, are discussed.
|
|
18. |
- Serrander, Lena, et al.
(author)
-
Selective Inhibition of IgG-Mediated Phagocytosis in Gelsolin-Deficient Murine Neutrophils
- 2000
-
In: Journal of Immunology. - 0022-1767 .- 1550-6606. ; 165:5, s. 2451-2457
-
Journal article (peer-reviewed)abstract
- Phagocytosis and the microbicidal functions of neutrophils require dynamic changes of the actin cytoskeleton. We have investigated the role of gelsolin, a calcium-dependent actin severing and capping protein, in peripheral blood neutrophils from gelsolin-null (Gsn−) mice. The phagocytosis of complement opsonized yeast was only minimally affected. In contrast, phagocytosis of IgG-opsonized yeast was reduced close to background level in Gsn− neutrophils. Thus, gelsolin is essential for efficient IgG- but not complement-mediated phagocytosis. Furthermore, attachment of IgG-opsonized yeast to Gsn− neutrophils was reduced (∼50%) but not to the same extent as ingestion (∼73%). This was not due to reduced surface expression of the Fcγ-receptor or its lateral mobility. This suggests that attachment and ingestion of IgG-opsonized yeast by murine neutrophils are actin-dependent and gelsolin is important for both steps in phagocytosis. We also investigated granule exocytosis and several steps in phagosome processing, namely the formation of actin around the phagosome, translocation of granules, and activation of the NADPH-oxidase. All these functions were normal in Gsn− neutrophils. Thus, the role of gelsolin is specific for IgG-mediated phagocytosis. Our data suggest that gelsolin is part of the molecular machinery that distinguishes complement and IgG-mediated phagocytosis. The latter requires a more dynamic reorganization of the cytoskeleton.
|
|
19. |
- Sommer, Gerald, et al.
(author)
-
Information Society Technologies (IST) programme : Final Report
- 2005
-
Reports (other academic/artistic)abstract
- To summarize, the VISATEC project was initiated to combine the specific scientific competencies of the research groups at CAU and LiU, together with the industrial view on vision applications, in order to develop novel, more robust algorithms for object localization and recognition. This goal was achieved by a two-fold strategy, whereby on the one hand more robust basic algorithms were developed and on the other hand a method for the combination of these algorithms was devised. In particular, the latter confirmed the consortium’s belief that an appropriate combination of a number of basic algorithms will lead to more robust results than a single method could do.However, the multi-cue integration is just one algorithm of many that were developed in the VISATEC project. All developed algorithms are described in some detail in the remainder of this report. An overview of the respective publications can be found in appendix.Despite some difficulties that were encountered on the way, we as a consortium feel that the VISATEC project was a success. That this is not only our opinion reflects in the outcome of the final review. We believe that the work that was done during these three years of the project, not only furthered our understanding of the matter, but also added to the knowledge within the scientific community and showed new possibilities for industrial vision applications.
|
|
20. |
- Tinetti, Giovanna, et al.
(author)
-
The science of EChO
- 2010
-
In: Proceedings of the International Astronomical Union. - 1743-9213 .- 1743-9221. ; 6:S276, s. 359-370
-
Journal article (peer-reviewed)abstract
- The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life. The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole. EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates. © International Astronomical Union 2011.
|
|
21. |
- Weidinger, C, et al.
(author)
-
Distinct Regulation of Intrinsic Apoptosis in Benignand Malignant Thyroid Tumours
- 2010
-
In: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 0018-5043 .- 1439-4286. ; 42:8, s. 553-556
-
Journal article (peer-reviewed)abstract
- Aberrations in the control of apoptosis represent a central feature of thyroid carcinogenesis. However, little is known about the regulation of components of the intrinsic apoptosis pathway in the thyroid. Using a real-time PCR approach we investigated the mRNA expression levels of Caspase3, Caspase3 s, xIAP, Bad, and β-actin in a panel of 79 thyroid tumours. Additionally, we assessed the activation status of Caspase3 by immunohistochemistry. In the present study, we provide first evidence for a deregulation of the intrinsic apoptosis pathway on the transcriptional and post-transcriptional level. Thus, malignant thyroid tumours revealed a significant downregulation of the proapoptotic Bad. In contrast Caspase3 s, an alternative splice variant of Caspase3 with anti-apoptotic characteristics, was upregulated in follicular and anaplastic cancers. Moreover, papillary thyroid tumours revealed a significant upregulation of Caspase3 mRNA. On the post-translational level, thyroid malignancies featured an impairment in the activation of Caspase3, since activated Caspase3 accumulated exclusively in the cytoplasm of thyroid cancer cells, whereas follicular adenoma and normal thyroid tissues showed no cytoplasmatic but nuclear Caspase3 distribution. Further knowledge on apoptosis-deregulation during thyroid carcinogenesis might confer diagnostic and therapeutic benefits in the management of thyroid cancer.
|
|