2,069 research outputs found
A Grid Middleware for Ontology Access
Many advanced grid applications need access to ontologies represent-ing knowledge about a certain application domain. To deal with the high heterogeneity of available ontologies, we propose a general ser-vice-oriented middleware for making ontologies accessible to grid ap-plications. Our implementation is integrated in the German D-Grid in-frastructure and provides several applications a uniform access to biomedical ontologies such as Gene Ontology, NCI Thesaurus and several OBO ontologies
Polymorphism of the tumor necrosis factor beta gene in systemic lupus erythematosus
We investigated the Nco I restriction fragment
length polymorphism (RFLP) of the tumor necrosis
factor beta (TNFB) gene in 173 patients with systemic
lupus erythematosus (SLE), 192 unrelated
healthy controls, and eleven panel families, all of German
origin. The phenotype frequency of the TNFB*I
allele was significantly increased in patients compared
to controls (63.6% vs 47.1%, RR = 1.96, p <0.002).
The results of a two-point haplotype statistical analysis
between TNFB and HLA alleles show that there is linkage
disequilibrium between TNFB*I and HLA-A1,
Cw7, B8, DR3, DQ2, and C4A DE. The frequency of
TNFB*I was compared in SLE patients and controls in
the presence or absence of each of these alleles.
TNFB*I is increased in patients over controls only in
the presence of the mentioned alleles. Therefore, the
whole haplotypeA1, Cw7, B8, TNFB* I, C4A DE, DR3,
DQ2 is increased in patients and it cannot be determined
which of the genes carried by this haplotype is
responsible for the susceptibility to SLE. In addition,
two-locus associations were analyzed in 192 unrelated
healthy controls for TNFB and class I alleles typed by
serology, and for TNFB and class II alleles typed by
polymerase chain reaction/oligonucleotide probes. We
found positive linkage disequilibrium between
TNFB*I and the following alleles: HLA-A24, HLA-B8,
DRBI*0301, DRBI*ll04, DRBI*1302, DQAI*0501, DQBI*0201, DQBI*0604, and DPBI*OIO1. TNFB*2
is associated with HLA-B7, DRBI*1501, and
DQB I *0602
Research core drilling in the Manson impact structure, Iowa
The Manson impact structure (MIS) has a diameter of 35 km and is the largest confirmed impact structure in the United States. The MIS has yielded a Ar-40/Ar-39 age of 65.7 Ma on microcline from its central peak, an age that is indistinguishable from the age of the Cretaceous-Tertiary boundary. In the summer of 1991 the Iowa Geological Survey Bureau and U.S. Geological Survey initiated a research core drilling project on the MIS. The first core was beneath 55 m of glacial drift. The core penetrated a 6-m layered sequence of shale and siltstone and 42 m of Cretaceous shale-dominated sedimentary clast breccia. Below this breccia, the core encountered two crystalline rock clast breccia units. The upper unit is 53 m thick, with a glassy matrix displaying various degrees of devitrification. The upper half of this unit is dominated by the glassy matrix, with shock-deformed mineral grains (especially quartz) the most common clast. The glassy-matrix unit grades downward into the basal unit in the core, a crystalline rock breccia with a sandy matrix, the matrix dominated by igneous and metamorphic rock fragments or disaggregated grains from those rocks. The unit is about 45 m thick, and grains display abundant shock deformation features. Preliminary interpretations suggest that the crystalline rock breccias are the transient crater floor, lifted up with the central peak. The sedimentary clast breccia probably represents a postimpact debris flow from the crater rim, and the uppermost layered unit probably represents a large block associated with the flow. The second core (M-2) was drilled near the center of the crater moat in an area where an early crater model suggested the presence of postimpact lake sediments. The core encountered 39 m of sedimentary clast breccia, similar to that in the M-1 core. Beneath the breccia, 120 m of poorly consolidated, mildly deformed, and sheared siltstone, shale, and sandstone was encountered. The basal unit in the core was another sequence of sedimentary clast breccia. The two sedimentary clast units, like the lithologically similar unit in the M-1 core, probably formed as debris flows from the crater rim. The middle, nonbrecciated interval is probably a large, intact block of Upper Cretaceous strata transported from the crater rim with the debris flow. Alternatively, the sequence may represent the elusive postimpact lake sequence
VLT Diffraction Limited Imaging and Spectroscopy in the NIR: Weighing the black hole in Centaurus A with NACO
We present high spatial resolution near-infrared spectra and images of the
nucleus of Centaurus A (NGC 5128) obtained with NAOS-CONICA at the VLT. The
adaptive optics corrected data have a spatial resolution of 0.06" (FWHM) in K-
and 0.11" in H-band, four times higher than previous studies. The observed gas
motions suggest a kinematically hot disk which is orbiting a central object and
is oriented nearly perpendicular to the nuclear jet. We model the central
rotation and velocity dispersion curves of the [FeII] gas orbiting in the
combined potential of the stellar mass and the (dominant) black hole. Our
physically most plausible model, a dynamically hot and geometrically thin gas
disk, yields a black hole mass of M_bh = (6.1 +0.6/-0.8) 10^7 M_sun. As the
physical state of the gas is not well understood, we also consider two limiting
cases: first a cold disk model, which completely neglects the velocity
dispersion; it yields an M_bh estimate that is almost two times lower. The
other extreme case is to model a spherical gas distribution in hydrostatic
equilibrium through Jeans equation. Compared to the hot disk model the best-fit
black hole mass increases by a factor of 1.5. This wide mass range spanned by
the limiting cases shows how important the gas physics is even for high
resolution data. Our overall best-fitting black hole mass is a factor of 2-4
lower than previous measurements. With our revised M_bh estimate, Cen A's
offset from the M_bh-sigma relation is significantly reduced; it falls above
this relation by a factor of ~2, which is close to the intrinsic scatter of
this relation. (Abridged)Comment: 12 pages, 14 figures, including minor changes following the referee
report; accepted for publication in The Astrophysical Journa
Local bifurcations in differential equations with state-dependent delay
This is the author accepted manuscript. The final version is available from AIP Publishing via the DOI in this record.A common task when analysing dynamical systems is the determination of normal forms near local bifurcations
of equilibria. As most of these normal forms have been classified and analysed, finding which particular class
of normal form one encounters in a numerical bifurcation study guides follow-up computations.
This paper builds on normal form algorithms for equilibria of delay differential equations with constant delay
that were developed and implemented in DDE-Biftool recently. We show how one can extend these methods
to delay-differential equations with state-dependent delay (sd-DDEs). Since higher degrees of regularity of
local center manifolds are still open for sd-DDEs, we give an independent (still only partial) argument which
phenomena from the truncated normal must persist in the full sd-DDE. In particular, we show that all
invariant manifolds with a sufficient degree of normal hyperbolicity predicted by the normal form exist also
in the full sd-DDEJ.S. gratefully acknowledges the financial support
of the EPSRC via grants EP/N023544/1 and
EP/N014391/1. J.S. has also received funding from the
European Unionâs Horizon 2020 research and innovation
programme under Grant Agreement number 643073
Fragen des Arbeits-, Tier- und Umweltschutzes bei der Schweinemast in verschiedenen Systemen unter besonderer BerĂŒcksichtigung mikrobieller Belastungen
Vor dem Hintergrund hĂ€ufiger Atemwegserkrankungen bei Schweinen und landwirtschaftlich BeschĂ€ftigten war es das Ziel eines interdisziplinĂ€ren Verbundprojektes, Belastungen von Mensch, Tier und Umwelt in ökologischen und konventionellen Haltungssystemen fĂŒr die Schweinemast zu erfassen. Die Untersuchungen wurden in zwei konventionellen (Stall A, B) (BVT-Stall, 50% reduzierter Schlitzanteil, ZwangsbelĂŒftung) und zwei ökologischen StĂ€llen durchgefĂŒhrt: Stall C (Praxisstall: Tiefstreu, freie Fenster-LĂŒftung), Stall D (Praxisstall: EU-Ăko-VO, Trauf-First-LĂŒftung). Ăber 2 Mastperioden (je 3 Messungen; kalte / warme Jahreszeit) wurden die Parameter erfasst: luftgetragene Endotoxine, Schimmelpilze, Bakterien mit Differenzierung, arbeitsmedizinische Staubfraktionen, Materialproben, Staubfraktion PM10, NH3, CO2 und CH4, Lufttemperatur, Luftfeuchte. Die Beschreibung der Tiergesundheit erfolgte ĂŒber serologische (Mycoplasmen, PRRS-, Influenza-A- und Circo-Virus) und koprologische (Parasitenbefall) Analysen und ĂŒber Schlachtkörper- und Organbefundungen (Lunge, Pleura, Perikard, Leber).
Am Beispiel der Endotoxin-Konzentration wurden die z.T. sehr hohen biologischen Belastungen deutlich: Stall C (Median: 14.495 EU/m3), Stall A/B (5.544 EU/m3), Stall D (2.876 EU/m3). Personengetragene Messungen fĂŒhrten zu deutlich höheren Werten. Die CO2- und NH3-Konzentrationen lagen in allen StĂ€llen im Durchschnitt deutlich unter dem Grenzwert von 3000 ppm bzw. 20 ppm. In Stall C und D war die CH4-Konzentration allerdings höher als in Stall A/B (oberer Bereich der Literaturangaben). AuffĂ€llige Lungenbefunde fanden sich bei ca. 45% der untersuchten Schlachttiere, unabhĂ€ngig vom Haltungssystem; parasitĂ€re LeberverĂ€nderungen wurden ausschlieĂlich in den StĂ€llen C und D ermittelt.
Die Untersuchungsergebnisse unterstreichen die Bedeutung der AusfĂŒhrung, Dimensionierung und Regelung des LĂŒftungssystems sowie die Sauberkeit bzw. Hygiene und insbesondere das Betriebsmanagement im Stall und ihre SchlĂŒsselrolle hinsichtlich der Freisetzungsmengen von Schadstoffen sowie der Tiergesundheit. DemgegenĂŒber kommt der Klassifizierung der Haltungsumwelt durch die Einteilung in Haltungssystemen nur eine geringe Aussagekraft zu
Hybridization of electron subbands in a double quantum well at quantizing magnetic field
We employ magnetocapacitance and far-infrared spectroscopy techniques to
study the spectrum of the double-layer electron system in a parabolic quantum
well with a narrow tunnel barrier in the centre. For gate-bias-controlled
asymmetric electron density distributions in this soft two-subband system we
observe both individual subband gaps and double layer gaps at integer filling
factor . The bilayer gaps are shown to be either trivial common for two
subbands or caused by hybridization of electron subbands in magnetic field. We
describe the observed hybrid gaps at and within a simple model
for the modified bilayer spectrum.Comment: REVTeX, 24 pages, 9 figures included. Submitted to Phys. Rev.
Measurement of Electron Trapping in the CESR Storage Ring
The buildup of low-energy electrons has been shown to affect the performance
of a wide variety of particle accelerators. Of particular concern is the
persistence of the cloud between beam bunch passages, which can impose
limitations on the stability of operation at high beam current. We have
obtained measurements of long-lived electron clouds trapped in the field of a
quadrupole magnet in a positron storage ring, with lifetimes much longer than
the revolution period. Based on modeling, we estimate that about 7% of the
electrons in the cloud generated by a 20-bunch train of 5.3 GeV positrons with
16-ns spacing and population survive longer than 2.3 s in a
quadrupole field of gradient 7.4 T/m. We have observed a non-monotonic
dependence of the trapping effect on the bunch spacing. The effect of a witness
bunch on the measured signal provides direct evidence for the existence of
trapped electrons. The witness bunch is also observed to clear the cloud,
demonstrating its effectiveness as a mitigation technique.Comment: 6 pages, 9 figures, 28 citation
A brown dwarf companion to the intermediate-mass star HR6037
In the course of an imaging survey we have detected a visual companion to the
intermediate-mass star HR 6037. In this letter, we present two epoch
observations of the binary with NACO/VLT, and near-IR spectroscopy of the
secondary with ISAAC/VLT. The NACO observations allow us to confirm HR 6037B as
a co-moving companion. Its J and H band ISAAC spectra suggest the object has an
spectral type of M9+-1, with a surface gravity intermediate between that of 10
Myr dwarfs and field dwarfs with identical spectral type. The comparison of its
Ks-band photometry with evolutionary tracks allows us to derive a mass,
effective temperature, and surface gravity of 62+-20 MJup, Teff = 2330+-200 K,
and log g = 5.1+-0.2, respectively. The small mass ratio of the binary, -0.03,
and its long orbital period, -5000 yr, makes HR 6037 a rare and uncommon binary
system.Comment: (5 pages, 4 figures, accepted for publication in A&A Letters
Developing a Research Mentorship Program: The American Society of Pediatric Nephrology's Experience
Background: Most pediatric nephrologists work in academia. Mentor-mentee relationships provide support and guidance for successful research career. Mentorship program implementation is valuable in medical fields for providing research opportunities to young faculty.
Methods: The American Society of Pediatric Nephrology (ASPN) established a research mentorship program to (a) assist with matching of appropriate mentor-mentee dyads and (b) establish metrics for desirable mentor-mentee outcomes with two independent components: (1) the grants review workshop, a short-term program providing mentor feedback on grant proposals, and (2) the longitudinal program, establishing long-term mentor-mentee relationships. Regular surveys of both mentors and mentees were reviewed to evaluate and refine the program.
Results: Twelve mentees and 17 mentors participated in the grant review workshop and 19 mentees were matched to mentors in the longitudinal program. A review of NIH RePORTER data indicated that since 2014, 13 NIH grants have been awarded. Mentees in the longitudinal program reported that the program helped most with identifying an outside mentor, improving grant research content, and with general career development. Mentors perceived themselves to be most helpful in assisting with overall career plans. Email communications were preferred over phone or face-to-face communications. Mentees endorsed strong interest in staying in touch with their mentors and 100% of mentors expressed their willingness to serve in the future.
Conclusion: This mentorship program was initiated and supported by a relatively small medical society and has shown early success in cultivating mentoring relationships for a future generation of clinician-scientists
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