49 research outputs found
Analysis of test beam data taken with a prototype of TPC with resistive Micromegas for the T2K Near Detector upgrade
In this paper we describe the performance of a prototype of the High Angle
Time Projection Chambers (HA-TPCs) that are being produced for the Near
Detector (ND280) upgrade of the T2K experiment. The two HA-TPCs of ND280 will
be instrumented with eight Encapsulated Resistive Anode Micromegas (ERAM) on
each endplate, thus constituting in total 32 ERAMs. This innovative technique
allows the detection of the charge emitted by ionization electrons over several
pads, improving the determination of the track position. The TPC prototype has
been equipped with the first ERAM module produced for T2K and with the HA-TPC
readout electronics chain and it has been exposed to the DESY Test Beam in
order to measure spatial and dE/dx resolution. In this paper we characterize
the performances of the ERAM and, for the first time, we compare them with a
newly developed simulation of the detector response. Spatial resolution better
than 800 and dE/dx resolution better than 10% are observed for
all the incident angles and for all the drift distances of interest. All the
main features of the data are correctly reproduced by the simulation and these
performances fully fulfill the requirements for the HA-TPCs of T2K
Characterization of Charge Spreading and Gain of Encapsulated Resistive Micromegas Detectors for the Upgrade of the T2K Near Detector Time Projection Chambers
An upgrade of the near detector of the T2K long baseline neutrino oscillation
experiment is currently being conducted. This upgrade will include two new Time
Projection Chambers, each equipped with 16 charge readout resistive Micromegas
modules. A procedure to validate the performance of the detectors at different
stages of production has been developed and implemented to ensure a proper and
reliable operation of the detectors once installed. A dedicated X-ray test
bench is used to characterize the detectors by scanning each pad individually
and to precisely measure the uniformity of the gain and the deposited energy
resolution over the pad plane. An energy resolution of about 10% is obtained. A
detailed physical model has been developed to describe the charge dispersion
phenomena in the resistive Micromegas anode. The detailed physical description
includes initial ionization, electron drift, diffusion effects and the readout
electronics effects. The model provides an excellent characterization of the
charge spreading of the experimental measurements and allowed the simultaneous
extraction of gain and RC information of the modules
Measurements of the and -induced Coherent Charged Pion Production Cross Sections on by the T2K experiment
We report an updated measurement of the -induced, and the first
measurement of the -induced coherent charged pion production
cross section on nuclei in the T2K experiment. This is measured in a
restricted region of the final-state phase space for which
GeV, and , and at a mean
(anti)neutrino energy of 0.85 GeV using the T2K near detector. The measured
CC coherent pion production flux-averaged cross section on
is . The new measurement
of the -induced cross section on is . The results are compatible with both the NEUT
5.4.0 Berger-Sehgal (2009) and GENIE 2.8.0 Rein-Sehgal (2007) model
predictions
Measuring proliferation in breast cancer: practicalities and applications
Various methods are available for the measurement of proliferation rates in tumours, including mitotic counts, estimation of the fraction of cells in S-phase of the cell cycle and immunohistochemistry of proliferation-associated antigens. The evidence, advantages and disadvantages for each of these methods along with other novel approaches is reviewed in relation to breast cancer. The potential clinical applications of proliferative indices are discussed, including their use as prognostic indicators and predictors of response to systemic therapy
Regional and national guideline recommendations for digital ano-rectal examination as a means for anal cancer screening in HIV positive men who have sex with men: a systematic review
Measurements of the ΜΌ and ÎœÂŻÎŒ -induced coherent charged pion production cross sections on C12 by the T2K experiment
We report an updated measurement of the
Μ
Ό
-induced, and the first measurement of the
ÂŻ
Μ
Ό
-induced coherent charged pion production cross section on
12
C
nuclei in the Tokai-to-Kamioka experiment. This is measured in a restricted region of the final-state phase space for which
p
Ό
,
Ï
>
0.2
â
â
GeV
,
cos
(
Ξ
Ό
)
>
0.8
and
cos
(
Ξ
Ï
)
>
0.6
, and at a mean (anti)neutrino energy of 0.85 GeV using the T2K near detector. The measured
Μ
Ό
charged current coherent pion production flux-averaged cross section on
12
C
is
(
2.98
±
0.37
(
stat
)
±
0.31
(
syst
)
+
0.49
â
0.00
(
Q
2
â
model
)
)
Ă
10
â
40
â
â
cm
2
. The new measurement of the
ÂŻ
Μ
Ό
-induced cross section on
12
C
is
(
3.05
±
0.71
(
stat
)
±
0.39
(
syst
)
+
0.74
â
0.00
(
Q
2
â
model
)
)
Ă
10
â
40
â
â
cm
2
. The results are compatible with both the NEUT 5.4.0 Berger-Sehgal (2009) and GENIE 2.8.0 Rein-Sehgal (2007) model predictions
Limits to simplified calculation of uncut chip thickness in milling
Modelling of forces and temperatures for mechanical cutting processes is mainly based on the prevailing local uncut chip geometry. In this context, most researchers use a simplified equation for calculating the uncut chip thickness in milling processes, which neglects the tool movement in feed direction and simplifies the chip thickness. The simplified equation can be easily evaluated, but also adds errors to the calculation results. These errors are typically neglected without knowledge of their exact size. However, the resulting error is dependent on the cutting parameters like cutting speed, tool feed and radial tool engagement and can be very large. In order to quantify the resulting error for different cutting conditions, a novel approach for a more precise calculation of the uncut chip thickness is presented in this paper. Using this new calculation model the uncut chip thickness is determined for industrial relevant cutting parameters and tool dimensions in the first step. The second step includes the direct comparison of the calculated values to the simplified calculation. In this way, the resulting error is illustrated for different cutting situations, mainly focusing on full slot milling and the contact area, where the workpiece surface is generated. As a result, limits for the application of the simplified engagement calculation are presented. In case the limits are exceeded, a more complex and more accurate calculation of the uncut chip thickness has to be used
The Jak1 SH2 domain does not fulfill a classical SH2 function in Jak/STAT signaling but plays a structural role for receptor interaction and up-regulation of receptor surface expression
The presence of a Src homology 2 (SH2) domain sequence similarity in the sequence of Janus kinases (Jaks) has been discussed since the first descriptions of these enzymes. We performed an in depth study to determine the function of the Jak1 SH2 domain. We investigated the functionality of the Jak1 SH2 domain by stably reconstituting Jak1-defective human fibrosarcoma cells U4C with endogenous amounts of Jak1 in which the crucial arginine residue Arg466 within the SH2 domain has been replaced by lysine. This mutant still binds to the receptor subunits gp130 and OSMR. Moreover, the SH2 R466K mutation does not affect the subcellular distribution of Jak1 as assessed by cell fractionation and confocal microscopy of cells expressing endogenous levels of non-tagged or a yellow fluorescent protein (YFP)-tagged Jak1-R466K, respectively. Likewise, the signaling capacity of Jak1 was not affected by this point mutation. However, we found that the SH2 domain is structurally important for cytokine receptor binding and surface expression of the OSMR