761 research outputs found
An astronomical analysis of the data in the pseudo-Hipparchus palimpsest in the Codex Climaci Rescriptus
In 2022, Gysembergh et al. published a paper in JHA claiming âNew evidence for Hipparchusâ Star Catalogueâ. In this paper we challenge this hypothesis by stating that (a) we disagree with their astronomical dating and find inconsistencies by using the given numbers, and (b) the terminology and the data format used in the palimpsest do not match Hipparchus or anybody else. Therefore, the palimpsest does not prove anything about Hipparchusâs star catalogue nor did Hipparchus use rectangular constellation borders. Specifically, the constellation of Corona Borealis, typically depicted as a circle since Babylonian times, is not considered a rectangle by Hipparchus. Furthermore, a palimpsest that cannot be dated properly does not confirm the long-known relationship between Hipparchus and Ptolemy as the authors claim.Otto Neugebauer FellowshipPeer Reviewe
SiS in the circumstellar envelope of IRC +10126: maser and quasi-thermal emission
We present new Effelsberg-100 m, ATCA, and VLA observations of rotational SiS
transitions in the circumstellar envelope (CSE) of IRC +10216. Thanks to the
high angular resolution achieved by the ATCA observations, we unambiguously
confirm that the molecule's J=1-0 transition exhibits maser action in this CSE,
as first suggested more than thirty years ago. The maser emission's radial
velocity peaking at a local standard of rest velocity of -39.8620.065 km/s
indicates that it arises from an almost fully accelerated shell. Monitoring
observations show time variability of the SiS (1-0) maser. The two lowest-
SiS quasi-thermal emission lines trace a much more extended emitting region
than previous high-J SiS observations. Their distributions show that the SiS
quasi-thermal emission consists of two components: one is very compact
(radius<1.5", corresponding to <3 cm), and the other extends
out to a radius >11". An incomplete shell-like structure is found in the
north-east, which is indicative of existing SiS shells. Clumpy structures are
also revealed in this CSE. The gain of the SiS (1-0) maser (optical depths of
about -5 at the blue-shifted side and, assuming inversion throughout the entire
line's velocity range, about -2 at the red-shifted side) suggests that it is
unsaturated. The SiS (1-0) maser can be explained in terms of ro-vibrational
excitation caused by infrared pumping, and we propose that infrared continuum
emission is the main pumping source.Comment: Accepted for publication in ApJ. A high-resolution version can be
found at https://gongyan2444.github.io/pdf/cw-leo-sis.pdf 3D movies of SiS
cubes can be found at https://gongyan2444.github.io/movie/sis10-3d.avi and
https://gongyan2444.github.io/movie/sis21-3d.av
A study of the variability in the hydrochemical factors in the Baltic Sea on the basis of two anchor stations September 1967 and May 1968
The present study was undertaken to investigate the physical and chemical variability in the eastern Gotland Basin. This can serve as an example for the variability in the inner part of an adjacent sea with small tidal influence. Two anchor stations of about four days duration were made, with R.V. "Alkor" in September 1967 and with F.R.V. "Anton Dohrn" in May 1968. On the basis of variations in the physical parameters, and also from continuous recordings of salinity and temperature, c.f., of oxygen and temperature, the presence of internal waves is demonstrated. The variability in the chemical data not only indicate internal waves but also proves the patchlike structure of the water masses with regard to biochemical parameters. The two anchor stations were made during periods of partial and of total stagnation in the deeper parts of the Gotland Basin.
Ziel dieser Arbeit ist eine Beschreibung der physikalisch chemischen Veränderlichkeit im Üstlichen Gotland-Becken, und zwar als Beispiel fßr die Veränderlichkeit im inneren Teil eines gezeitenarmen Nebenmeeres. Zwei viertägige Ankerstationen wurden durchgefßhrt, im September 1967 und Mai 1968, mit "Alkor" und "Anton Dohr". Auf Grund der Variationen in den physikalischen Parametern und auch von den kontinuierlichen Registrierungen von Salzgehalt und Temperatur, bzw. von Sauerstoff und Temperatur, werden interne Wellen nachgewiesen. Von der Veränderlichkeit der chemischen Parameter werden neben internen Wellen auch wolkenartige Strukturen der Wassermassen im Bezug auf biochemische Eigenschaften demonstriert. Beide Dauerstationen fielen in einer Periode von teilweiser und von voller Stagnation im Gotland-Becken
Correlations, deviations and expectations: the Extended Principle of the Common Cause
The Principle of the Common Cause is usually understood to provide causal explanations for probabilistic correlations obtaining between causally unrelated events. In this study, an extended interpretation of the principle is proposed, according to which common causes should be invoked to explain positive correlations whose values depart from the ones that one would expect to obtain in accordance to her probabilistic expectations. In addition, a probabilistic model for common causes is tailored which satisfies the generalized version of the principle, at the same time including the standard conjunctive-fork model as a special case
PegfilgrastimâÂąâciprofloxacin for primary prophylaxis with TAC (docetaxel/doxorubicin/cyclophosphamide) chemotherapy for breast cancer. Results from the GEPARTRIO study
Background: TAC (docetaxel/doxorubicin/cyclophosphamide) is associated with high incidences of grade 4 neutropenia and febrile neutropenia (FN). This analysis compared the efficacies of four regimens for primary prophylaxis of FN and related toxic effects in breast cancer patients receiving neoadjuvant TAC. Patients and methods: Patients with stage T2-T4 primary breast cancer were scheduled to receive 6-8 cycles of TAC. Primary prophylaxis was: ciprofloxacin 500 mg orally twice daily on days 5-14 (nâ=â253 patients; 1478 cycles), daily granulocyte colony-stimulating factor (G-CSF) (filgrastim 5 Îźg/kg/day or lenograstim 150 Îźg/m2/day) on days 5-10 (nâ=â377; 2400 cycles), pegfilgrastim 6 mg on day 2 (nâ=â305; 1930 cycles), or pegfilgrastim plus ciprofloxacin (nâ=â321; 1890 cycles). Results: Pegfilgrastim with/without ciprofloxacin was significantly more effective than daily G-CSF or ciprofloxacin in preventing FN (5% and 7% versus 18% and 22% of patients; all Pâ<â0.001), grade 4 neutropenia, and leukopenia. Pegfilgrastim plus ciprofloxacin completely prevented first cycle FN (Pâ<â0.01 versus pegfilgrastim alone) and fatal neutropenic events. Conclusion: Ciprofloxacin alone, or daily G-CSF from day 5-10 (as in common practice), provided suboptimal protection against FN and related toxic effects in patients receiving TAC. Pegfilgrastim was significantly more effective in this setting, especially if given with ciprofloxaci
Ăkologische Untersuchungen zur Nitrifikation in Nord-und Ostsee
Ammonia, nitrite and nitrate were regularly estimated at several stations in the Kieler Bucht (western Baltic Sea) since November 1964. There are considerable seasonal changes in the contents of these 3 nitrogen compounds with impressive maxima of nitrite and nitrate in February or at the beginning of March. The great increase of nitrite and nitrate during the winter and also a smaller increase in summer are mainly caused by oxidation of ammonia, first to nitrite and then to nitrate, by nitrifying bacteria. In consequence chemoautotrophic nitrite- and nitratebacteria could be found in the water as well as in sediments all over the Kieler Bucht and also in the North Sea around the isle of Helgoland. These nitrifying bacteria are able to oxidize ammonia or nitrite in salinity conditions typical for the western Baltic Sea and the North Sea
Research perspectives in the etiology of congenital anorectal malformations using data of the International Consortium on Anorectal Malformations: evidence for risk factors across different populations
Contains fulltext :
89406.pdf (publisher's version ) (Closed access)PURPOSE: The recently established International Consortium on Anorectal Malformations aims to identify genetic and environmental risk factors in the etiology of syndromic and nonsyndromic anorectal malformations (ARM) by promoting collaboration through data sharing and combined research activities. METHODS: The consortium attempts to recruit at least 1,000 ARM cases. DNA samples are collected from case-parent triads to identify genetic factors involved in ARM. Several genetic techniques will be applied, including SNP arrays, gene and whole exome sequencing, and a genome-wide association study. Questionnaires inquiring about circumstances before and during pregnancy will be used to obtain environmental risk factor data. RESULTS: Currently, 701 ARM cases have been recruited throughout Europe. Clinical data are available from all cases, and DNA samples and questionnaire data mainly from the Dutch and German cases. Preliminary analyses on environmental risk factors in the Dutch and German cohort found associations between ARM and family history of ARM, fever during first trimester of pregnancy and maternal job exposure to cleaning agents and solvents. CONCLUSION: First results show that both genetic and environmental factors may contribute to the multifactorial etiology of ARM. The International Consortium on Anorectal Malformations will provide possibilities to study and detect important genes and environmental risk factors for ARM, ultimately resulting in better genetic counseling, improved therapies, and primary prevention.1 november 201
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