The determination of the strong coupling constant
α
s
(
m
Z
)
from H1 inclusive and dijet cross section data
1
exploits perturbative QCD predictions in next-to-next-to-leading order (NNLO)
2
–
4
. ...An implementation error in the NNLO predictions was found
4
which changes the numerical values of the predictions and the resulting values of the fits. Using the corrected NNLO predictions together with inclusive jet and dijet data, the strong coupling constant is determined to be
α
s
(
m
Z
)
=
0.1166
(
19
)
exp
(
24
)
th
. Complementarily,
α
s
(
m
Z
)
is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value
α
s
(
m
Z
)
=
0.1147
(
25
)
tot
obtained is consistent with the determination from jet data alone. Corrected figures and numerical results are provided and the discussion is adapted accordingly.
The EUROMET.T-K3 comparison is the regional extension of CCT-K3. The comparison involved the six European national metrology institutes (NMIs) previously involved in CCT-K3 (LNE-INM/CNAM, SMU, INRiM, ...NMi-VSL, NPL, PTB) and 18 additional European national laboratories. The comparison was divided into five different loops, each coordinated by a co-pilot chosen from the laboratories having participated in the CCT-K3 comparison. LNE-INM/CNAM played the role of pilot in linking the five loops. In each loop, an artifact in the form of a standard platinum resistance thermometer (SPRT, 25 Ω) was circulated among the participating laboratories. To have sufficient information about the possible drift of the SPRTs, the co-pilots performed a calibration over the full temperature range at the beginning and at the end of the loop. A EUROMET reference value (ERV), taking into account the whole comparison, was defined, and the differences (
T
Lab
−
T
ERV
) were calculated with the associated uncertainties. The method for establishing the link between the participants in CCT-K3 and in EUROMET.T-K3 is described.
The parameters of the electroweak theory are determined in a combined electroweak and QCD analysis using all deep-inelastic Formula omitted and Formula omitted neutral current and charged current ...scattering cross sections published by the H1 Collaboration, including data with longitudinally polarised lepton beams. Various fits to Standard Model parameters in the on-shell scheme are performed. The mass of the W boson is determined as Formula omitted. The axial-vector and vector couplings of the light quarks to the Z boson are also determined. Both results improve the precision of previous H1 determinations based on HERA-I data by about a factor of two. Possible scale dependence of the weak coupling parameters in both neutral and charged current interactions beyond the Standard Model is also studied. All results are found to be consistent with the Standard Model expectations.
Functional magnetic resonance imaging (fMRI), which is a technique useful for non-invasive mapping of brain function, is well suited for studying the visual system. This review highlights current ...clinical applications and research studies involving patients with visual deficits. Relevant reports regarding the investigation of the brain's role in visual processing and some newer fMRI techniques are also reviewed. Functional magnetic resonance imaging has been used for presurgical mapping of visual cortex in patients with brain lesions and for studying patients with amblyopia, optic neuritis, and residual vision in homonymous hemianopia. Retinotopic borders, motion processing, and visual attention have been the topics of several fMRI studies. These reports suggest that fMRI can be useful in clinical and research studies in patients with visual deficits.
Background The purpose of this study is to evaluate serum bicarbonate level as a risk factor for renal outcomes, cardiovascular events, and mortality in patients with chronic kidney disease (CKD). ...Study Design Observational cohort study. Setting & Participants 3,939 participants with CKD stages 2-4 who enrolled in the Chronic Renal Insufficiency Cohort (CRIC) between June 2003 and December 2008. Predictor Serum bicarbonate level. Outcomes Renal outcomes, defined as end-stage renal disease (either initiation of dialysis therapy or kidney transplantation) or 50% reduction in estimated glomerular filtration rate (eGFR); atherosclerotic events (myocardial infarction, stroke, or peripheral arterial disease); congestive heart failure events; and death. Measurements Time to event. Results Mean eGFR was 44.8 ± 16.8 (SD) mL/min/1.73 m2 , and median serum bicarbonate level was 24 (IQR, 22-26) mEq/L. During a median follow-up of 3.9 years, 374 participants died, 767 had a renal outcome, 332 experienced an atherosclerotic event, and 391 had a congestive heart failure event. In adjusted analyses, the risk of developing a renal end point was 3% lower per 1-mEq/L increase in serum bicarbonate level (HR, 0.97; 95% CI, 0.94-0.99; P = 0.01). The association was stronger for participants with eGFR >45 mL/min/1.73 m2 (HR, 0.91; 95% CI, 0.85-0.97; P = 0.004). The risk of heart failure increased by 14% (HR, 1.14; 95% CI, 1.03-1.26; P = 0.02) per 1-mEq/L increase in serum bicarbonate level over 24 mEq/L. Serum bicarbonate level was not associated independently with atherosclerotic events (HR, 0.99; 95% CI, 0.95-1.03; P = 0.6) and all-cause mortality (HR, 0.98; 95% CI, 0.95-1.02; P = 0.3). Limitations Single measurement of sodium bicarbonate. Conclusions In a cohort of participants with CKD, low serum bicarbonate level was an independent risk factor for kidney disease progression, particularly for participants with preserved kidney function. The risk of heart failure was higher at the upper extreme of serum bicarbonate levels. There was no association between serum bicarbonate level and all-cause mortality or atherosclerotic events.
Measurements of
D
∗
(
2010
)
meson production in diffractive deep inelastic scattering
(
5
<
Q
2
<
100
GeV
2
)
are presented which are based on HERA data recorded at a centre-of-mass energy
s
=
319
...GeV
with an integrated luminosity of 287 pb
-
1
. The reaction
e
p
→
e
X
Y
is studied, where the system
X
, containing at least one
D
∗
(
2010
)
meson, is separated from a leading low-mass proton dissociative system
Y
by a large rapidity gap. The kinematics of
D
∗
candidates are reconstructed in the
D
∗
→
K
π
π
decay channel. The measured cross sections compare favourably with next-to-leading order QCD predictions, where charm quarks are produced via boson-gluon fusion. The charm quarks are then independently fragmented to the
D
∗
mesons. The calculations rely on the collinear factorisation theorem and are based on diffractive parton densities previously obtained by H1 from fits to inclusive diffractive cross sections. The data are further used to determine the diffractive to inclusive
D
∗
production ratio in deep inelastic scattering.
Water triple-point cells are the basis for the definition of the kelvin and for the realization of the International Temperature Scale of 1990. The temperature differences between the cells are ...mainly caused by impurities arising in the cell water from the dissolution of the cell envelope (borosilicate glass or quartz). In order to investigate the effects of such impurities on the realized triple-point temperature, water triple-point cells doped with known amounts of Si and Na impurities (
0.1
μ
mol
·
mol
-
1
to
1
μ
mol
·
mol
-
1
of Si and
0.2
μ
mol
·
mol
-
1
to
2
μ
mol
·
mol
-
1
of Na) were manufactured at VSL by adding gravimetric mixtures of a Si standard reference material and ultra high-purity water to the cell high-purity water. Water samples were taken from the manufactured cells, partitioned into three samples, and distributed to different laboratories for isotope and impurity analysis (inductively coupled plasma mass spectrometry, ICPMS). The results of two independent ICPMS analyses were compared with impurity calculations based on the gravimetric data of the prepared mixtures and manufactured cells. One undoped cell manufactured by UME and one undoped cell manufactured by VSL were intercompared at both VSL and SMD to demonstrate the equivalence of the manufacturing processes of UME and VSL. The triple-point temperatures realized by the doped cells and the undoped cell manufactured by VSL were measured at SMD. The results showed that, in doped cells, the equilibration time after the last freezing is directly dependent on the impurity concentration, and the temperature depression of doped triple-point-of-water cells is significantly greater than the values predicted by Raoult’s law for an ideal dilute solution.
In the big data era, the speed of analytical processing is influenced by the storage and retrieval capabilities to handle large amounts of data. While the distributed crunching applications ...themselves can yield useful information, the analysts face difficult challenges: they need to predict how much data to process and where, such that to get an optimum data crunching cost, while also respect deadlines and service level agreements within a limited budget. In today’s data centers, data processing on demand and data transfers requests coming from distributed applications are usually expressed as aperiodic tasks. In this paper, we challenge the problem of tasks scheduling with deadline constraints of aperiodic tasks within inter-Cloud environments. In massively multithreaded computing systems that deal with data-intensive applications, Hadoop and BaTs tasks arrive periodically, which challenges traditional scheduling approaches previously proposed for supercomputing. Here, we consider the deadline as the main constraint, and propose a method to estimate the number of resources needed to schedule a set of aperiodic tasks, considering both execution and data transfers costs. Starting from classical scheduling techniques, and considering asynchronous tasks handling, we analyze the possibility of decoupling task arriving from task creation, scheduling and execution, sets of actions that can be put into a peer-to-peer relation over a network or over a client–server architecture in the Cloud. Based on a mathematical model, and using different simulation scenarios, we prove the following statements: (1) multiple source of independent aperiodic tasks can be considered similar to a single one; (2) with respect to the global deadline, the tasks migration between different regional centers is the appropriate solution when the number of estimated resources exceed a data center capacity; and (3) in a heterogeneous data center, we need a higher number of resources for the same request in order to respect the deadline constraints. We believe such results will benefit researchers and practitioners alike, who are interested in optimizing the resource management in data centers according to novel challenges coming from next-generation big data applications.
Abstract
The strong coupling constant
$$\alpha _\mathrm{s}$$
α
s
is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic
ep
scattering (DIS) measured at HERA by ...the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of
$$\alpha _\mathrm{s} (m_\mathrm{Z})$$
α
s
(
m
Z
)
at the
Z
-boson mass
$$m_Z$$
m
Z
are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be
$$\alpha _\mathrm{s} (m_\mathrm{Z}) =0.1157\,(20)_\mathrm{exp}\,(29)_\mathrm{th}$$
α
s
(
m
Z
)
=
0.1157
(
20
)
exp
(
29
)
th
. Complementary,
$$\alpha _\mathrm{s} (m_\mathrm{Z})$$
α
s
(
m
Z
)
is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value
$$\alpha _\mathrm{s} (m_\mathrm{Z}) =0.1142\,(28)_\mathrm{tot}$$
α
s
(
m
Z
)
=
0.1142
(
28
)
tot
obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
The strong coupling constant Formula omitted is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration ...using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of Formula omitted at the Z-boson mass Formula omitted are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be Formula omitted. Complementary, Formula omitted is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value Formula omitted obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
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