84 research outputs found
EXTERNAL BARREL TEMPERATURE OF A SMALL BORE OLYMPIC RIFLE
Investigations on changes in a rifleâs barrel temperature during shooting in a rhythm typical for practitioners of Olympic shooting sports are presented. Walther KK300 (cal. 5.6 mm), a typical rifle often used in Olympic competitions, R50 RWS ammunition and a high speed thermographic camera were used in the study. Altair version 5 software was used to process thermal images and a stationary wavelet transform was applied to denoise signals for all the studied points. It was found that the temperature of the rifle barrel does not exceed 0.3°C after one shot whereas the total temperature increase does not exceed 5°C after taking 40 shots and does not affect the position of the hitting point on a target. In fact, contrary to popular belief, the so-called âwarming shotsâ are not done for barrel heating but for cleaning of remnants in the barrel
The European sea bass Dicentrarchus labrax genome puzzle: comparative BAC-mapping and low coverage shotgun sequencing
Abstract Background Food supply from the ocean is constrained by the shortage of domesticated and selected fish. Development of genomic models of economically important fishes should assist with the removal of this bottleneck. European sea bass Dicentrarchus labrax L. (Moronidae, Perciformes, Teleostei) is one of the most important fishes in European marine aquaculture; growing genomic resources put it on its way to serve as an economic model. Results End sequencing of a sea bass genomic BAC-library enabled the comparative mapping of the sea bass genome using the three-spined stickleback Gasterosteus aculeatus genome as a reference. BAC-end sequences (102,690) were aligned to the stickleback genome. The number of mappable BACs was improved using a two-fold coverage WGS dataset of sea bass resulting in a comparative BAC-map covering 87% of stickleback chromosomes with 588 BAC-contigs. The minimum size of 83 contigs covering 50% of the reference was 1.2 Mbp; the largest BAC-contig comprised 8.86 Mbp. More than 22,000 BAC-clones aligned with both ends to the reference genome. Intra-chromosomal rearrangements between sea bass and stickleback were identified. Size distributions of mapped BACs were used to calculate that the genome of sea bass may be only 1.3 fold larger than the 460 Mbp stickleback genome. Conclusions The BAC map is used for sequencing single BACs or BAC-pools covering defined genomic entities by second generation sequencing technologies. Together with the WGS dataset it initiates a sea bass genome sequencing project. This will allow the quantification of polymorphisms through resequencing, which is important for selecting highly performing domesticated fish.Peer Reviewe
The Araucaria Project. An improved distance to the Sculptor spiral galaxy NGC 300 from its Cepheid variables
In a previous paper, we reported on the discovery of more than a hundred new
Cepheid variables in the Sculptor Group spiral NGC 300 from wide-field images
taken in the B and V photometric bands at ESO/La Silla. In this paper, we
present additional VI data, derive improved periods and mean magnitudes for the
variables, and construct period-luminosity relations in the V, I and the
reddening-independent (V-I) Wesenheit bands using 58 Cepheid variables with
periods between 11 and 90 days. We obtain tightly defined relations, and by
fitting the slopes determined for the LMC Cepheids by the OGLE II Project we
obtain reddening-corrected distances to the galaxy in all bands. We adopt as
our best value the distance derived from the reddening-free Wesenheit
magnitudes, which is 26.43 0.04 (random) 0.05 (systematic) mag. We
argue that our current distance result for NGC 300 is the most accurate which
has so far been obtained using Cepheid variables, and that it is largely free
from systematic effects due to metallicity, blending, and sample selection. It
agrees very well with the recent distance determination from the tip of the red
giant branch method obtained from HST data by Butler et al. (2004), and it is
consistent with the Cepheid distance to NGC 300 which was derived by Freedman
et al. (2001) from CCD photometry of a smaller sample of stars.Comment: Latex, Astronomical Journal in pres
The Araucaria Project. The Distance to the Local Group Galaxy NGC 6822 from Cepheid Variables discovered in a Wide-Field Imaging Survey
We have obtained mosaic images of NGC 6822 in V and I bands on 77 nights.
From these data, we have conducted an extensive search for Cepheid variables
over the entire field of the galaxy, and we have found 116 such variables with
periods ranging from 1.7 to 124 days. We used the long-period ( 5.6 days)
Cepheids to establish the period-luminosity relations in V, I and in the
reddening-independent Wesenheit index, which are all very tightly defined.
Fitting the OGLE LMC slopes in the various bands to our data, we have derived
distance values for NGC 6822 in V, I and which agree very
well among themselves. Our adopted best distance value from the reddening-free
Wesenheit index is 23.34 0.04 (statistical) 0.05 (systematic) mag.
This value agrees within the combined 1 sigma uncertainties with a previous
distance value derived for NGC 6822 by McAlary et al. from near-IR photometry
of 9 Cepheids, but our new value is significantly more accurate. We compare the
slopes of the Cepheid PL relation in V and I as determined in the five
best-observed nearby galaxies, which span a metallicity range from -1.0 to -0.3
dex, and find the data consistent with no metallicity dependence of the PL
relation slope in this range. Comparing the magnitudes of 10-day Cepheids with
the I-band magnitudes of the TRGB in the same set of galaxies, there is no
evidence either for a significant variation of the period-luminosity zero
points in V and I. The available data limit such a zero point variation to less
than 0.03 mag, in the considered low-metallicity regime.Comment: Latex, Astronomical Journal accepte
The Araucaria Project. The Distance to the Local Group Galaxy WLM from Cepheid Variables discovered in a Wide-Field Imaging Survey
We have conducted an extensive wide-field imaging survey for Cepheid
variables in the Local Group irregular galaxy WLM. From data obtained on 101
nights, we have discovered 60 Cepheids which include 14 of the 15 Cepheid
variables previously detected by Sandage and Carlson. Down to a period of 3
days, our Cepheid survey in WLM should be practically complete. Importantly, we
have found for the first time a long-period Cepheid (P=54.2 days) in this
galaxy, alleviating the puzzle that WLM with its many blue, massive stars does
not contain Cepheids with periods longer than about 10 days. Our data define
tight period-luminosity relations in V, I and the reddening-free Wesenheit
magnitude which are all extremely well fit by the
corresponding slopes of the LMC Cepheid PL relation, suggesting no change of
the PL relation slope down to a Cepheid metal abundance of about -1.0 dex, in
agreement with other recent studies. We derive a true distance modulus to WLM
of 25.144 0.03 (r) 0.07 (s) mag from our data, in good agreement with
the earlier 24.92 0.21 mag determination of Lee, Freedman and Madore
(1993a) from Cepheid variables. The quoted value of the systematic uncertainty
does not include the contribution from the LMC distance which we have assumed
to be 18.50 mag, as in the previous papers in our project.Comment: AJ accepte
Subcutaneous Panniculitis-like T-cell Lymphoma in Type 1 Neurofibromatosis: a Case Report
Neurofibromatosis 1 (NF-1) is an autosomal dominant genodermatosis with an increased risk of developing mesenchymal malignancies.A 28-year-old woman with NF-1 was admitted to our Department for deep ulcers on the right thigh. The ulcerations had appeared about two years earlier, and were initially diagnosed as pyoderma gangrenosum. The patient received immunosuppressive therapy but only marginal improvement was observed. Several months later, the disease progressed, so a skin biopsy was taken, establishing cytophagic histiocytic panniculitis. The patient was admitted to our Department for further therapy. After re-evaluation of histological slides, while taking into account the clinical presentation and previously established histological diagnosis, subcutaneous panniculitis-like T cell lymphoma (SPTL) was diagnosed. Chemotherapy (combination of fludarabine and cyclophosphamide) was started, resulting in almost complete remission of malignant lesions.To the best of our knowledge, this is the first report of the development of SPTL in NF-1.</span
The Araucaria Project. A Wide-Field Photometric Survey for Cepheid Variables in NGC 3109
We have obtained mosaic images of NGC 3109 in the V and I bands on 74 nights,
spanning approximately one year. From these data, we have conducted an
extensive search for Cepheid variables over the entire field of the galaxy,
resulting in the discovery of 113 variables with periods ranging from 3.4 to
31.4 days. In this sample, 76 Cepheids, including many long-period variables,
were not known before. For the previously known 45 Cepheids in this galaxy, our
data proved that reported periods were wrong for 14 objects; for nearly all
other previously known Cepheid variables we were able to significantly improve
on the periods. We construct period-luminosity relations from our data and
obtain reddening-corrected distance moduli of 25.72 0.05 mag in V, and
25.66 0.04 mag in I. The distance modulus derived form the
reddening-independent V-I Wesenheit index turns out to be significantly shorter
(25.54 0.05 mag), which indicates that in addition to the foreground
extinction of E(B-V) = 0.05 mag, there is an intrinsic to NGC 3109 redening of
about 0.05 mag. Our distance obtained based on the reddening-free Wesenheit
magnitudes is consistent with earlier distance determinations of NGC 3109 from
Cepheids, and the tip of the red giant branch. We will improve on our distance
and extinction determination combining our optical data with the follow-up
near-infrared observations of a subsample of NGC 3109 Cepheids.Comment: accepted to be published in the Ap
Impact of HPV infection on the clinical outcome of p-CAIR trial in head and neck cancer
The purpose of the study was to analyse the influence of HPV infection on the outcome of a randomized clinical trial of conventional (CF) versus 7-days-a-week postoperative radiotherapy (p-CAIR) for squamous cell cancer of the head and neck (SCCHN). Between 2001 and 2004, 279 patients with high-risk SCC of the larynx or cancer of the oral cavity/oropharynx were randomized to receive 63 Gy in fractions of 1.8 Gy given 5 days a week or 7 days a week (Radiother Oncol 87:155â163, 2008). The presence of HPV DNA in 131 archival paraffin blocks was assessed with multiplex quantitative real-time PCR using five consensus primers for the conservative L1 region and molecular beacon probes targeting 14 high-risk HPV subtypes. Following the RT-PCR procedure, we could determine the presence and type of HPV16, HPV18 and the other 12 less frequent oncogenic subtypes. Out of 131 samples, 9 were positive for HPV infection (6.9%), all of them with HPV16 subtype. None of the 65 laryngeal tumours was HPV positive. The 5-year LRC in HPV-positive patients was 100%, compared to 58% in the HPV-negative group (p = 0.02, log-rank test). Amongst 122 patients with HPV-negative tumours, 5-year LRC was 50.3% in p-CF versus 65.2 in p-CAIR (p = 0.37). HPV infection was associated with low expression of EGFR and cyclin D. This study demonstrates a favourable outcome for HPV-positive patients with SCCHN treated with postoperative radiotherapy. While considering the small number of HPV+ tumours, the data set can be considered as hypothesis generating only, the outcome raises new questions on the necessity of aggressive postoperative treatment in HPV+ patients
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