Unfolding Quantum Computer Readout Noise

In the current era of noisy intermediate-scale quantum (NISQ) computers, noisy qubits can result in biased results for early quantum algorithm applications. This is a significant challenge for interpreting results from quantum computer simulations for quantum chemistry, nuclear physics, high energy physics, and other emerging scientific applications. An important class of qubit errors are readout errors. The most basic method to correct readout errors is matrix inversion, using a response matrix built from simple operations to probe the rate of transitions from known initial quantum states to readout outcomes. One challenge with inverting matrices with large off-diagonal components is that the results are sensitive to statistical fluctuations. This challenge is familiar to high energy physics, where prior-independent regularized matrix inversion techniques (`unfolding') have been developed for years to correct for acceptance and detector effects when performing differential cross section measurements. We study various unfolding methods in the context of universal gate-based quantum computers with the goal of connecting the fields of quantum information science and high energy physics and providing a reference for future work. The method known as iterative Bayesian unfolding is shown to avoid pathologies from commonly used matrix inversion and least squares methods.Comment: 13 pages, 16 figures; v2 has a typo fixed in Eq. 3 and a series of minor modification

Utjecaj polimorfizma DGAT1 i LEP gena na osobine mlijeka holštajnskih prvotelki

The genes encoding the diacylglycerol O-acyltransferase (DGAT1) and leptin (LEP) became a functional candidate genes for lactation traits in cows. Several studies associated single nucleotide polymorphisms (SNP) in these genes with fat and protein content in milk, fat and protein yield, milk yield and some reproductive traits. Three reported SNPs in these genes were investigated in our study (DGAT1-K232A, LEP-R25C, LEP-A80V). One hundred and sixty-three primiparous dairy cows from one farm were genotyped. The milk yield, fat and protein yield, fat and protein content and the age at first calving were recorded. The frequencies of alleles and genotypes were assessed. The effect of genotypes on milk traits and age at first calving were studied using linear models. The assumption of the different allele frequencies resulting from selection aimed at milk yield was proved in DGAT1 and LEP-A80V. The significant effect (P<0.01) of DGAT1 polymorphism was estimated only for the fat content. No significant effect of individual LEP polymorphism on milk trait or age at first calving was estimated. No significant effect of combination of LEP polymorphisms was estimated for those traits. The effect of DGAT1 on the age at first calving was indicated.Geni koji kodiraju diacilglicerol O-aciltransferazu (DGAT1) i leptin (LEP) su funkcionalni geni za mliječne osobine krava. U nekoliko istraživanja povezani su polimorfizmi na pojedinačnim nukleotidima (SNP) tih gena sa sastavom i koncentracijom masti i proteina u mlijeku, količinom mlijeka, te nekim reproduktivnim svojstvima. U ovom su radu istraživani SNPs u tim genima (DGAT1-K232A, LEP-R25C, LEP-A80V). Ukupno je genotipizirano 163 krava prvotelki s jedne farme. Istraženi su sljedeći parametri: količina mlijeka, koncentracija i sastav masti i proteina, starost (dob) nakon prvog teljenja, frekvencije alela i genotipovi. Utjecaj genotipa na osobine mlijeka i dob kod prvog teljenja analizirani su linearnim modelom. Dokazana je pretpostavka različitih alelnih frekvencija u DGAT1 i LEP-A80V što je posljedica selekcije na količinu mlijeka. Signifikantan utjecaj (P<0,01) DGAT1 polimorfizma je utvrđen samo za sastav masti. Nije utvrđen signifikantan utjecaj pojedinačnih niti kombiniranih LEP polimorfizama na osobine mliječnosti, niti dob kod prvog teljenja. Postoje indikacije da DGAT1 gen utječe na dob prvog teljenja

Dynamical ionization ignition of clusters in intense and short laser pulses

The electron dynamics of rare gas clusters in laser fields is investigated quantum mechanically by means of time-dependent density functional theory. The mechanism of early inner and outer ionization is revealed. The formation of an electron wave packet inside the cluster shortly after the first removal of a small amount of electron density is observed. By collisions with the cluster boundary the wave packet oscillation is driven into resonance with the laser field, hence leading to higher absorption of laser energy. Inner ionization is increased because the electric field of the bouncing electron wave packet adds up constructively to the laser field. The fastest electrons in the wave packet escape from the cluster as a whole so that outer ionization is increased as well.Comment: 8 pages, revtex4, PDF-file with high resolution figures is available from http://mitarbeiter.mbi-berlin.de/bauer/publist.html, publication no. 24. Accepted for publication in Phys. Rev.

Novi tehnološki postupak u gajenju šuma za biološku kontrolu širenja pajasena (Ailanthus altissima /Mill./Swingle)

U tehničkom rešenju prikazan je postupak rešeavanja problema biološke kontrole invazivne vrste Ailanthus altissima (Mill./Swingle) na području Nacionalnog parka ,,Fruška gora'' primenom proreda kao mere gajenja šuma koristeći priom polni dimorfizam predmetne vrste. Za potrebe tehničkog rešenja, pored samo postupka prikazano je i stanje rešenosti problema u zemlji i svetu

DOUBLE SIZE FULLJET FIELD RAINFALL SIMULATOR FOR COMPLEX INTERRILL AND RILL EROSION STUDIES

Field observations and consecutive modelling of soil erosion events proved to be essential for understanding and predicting erosion and sediment transport. An experimental approach often utilizes a large variety of rainfall simulators. In this technical note a complex methodology is introduced, using a mobile rainfall simulator developed at the Czech Technical University in Prague. An experimental setup with two watered plots (16 + 1 m2) was established, which enables simultaneous measurements in two scales and monitoring of surface runoff, flow velocity, infiltration, sediment subsurface flow, vegetation cover effect suspended solids and phosphorus transport, surface roughness and surface evolution under rainfall and other variables. The simulator is built on a trailer transportable by car with folding arm carrying four FullJet WSQ nozzles operating independently. The configuration and water pressure 0.7 bar leads to the total watered area 2.4 x 9.6 m. Average drop size (d50) reaches 1.75 mm for 0.7 bar pressure. Christiansen uniformity index CU reaches 85%. A selection of experimental results highlights both the advantages and the weaknesses of the presented experimental setup

Is Bologna working? Employer and graduate reflections of the quality, value and relevance of business and management education in four European Union countries

This article focuses on the relevance of undergraduate business and management higher education from the perspectives of recent graduates and graduate employers in four European countries. Drawing upon the findings of an empirical qualitative study in which data was collated and analysed using grounded theory research techniques, the paper draws attention to graduates' and employers' perceptions of the value of higher education in equipping students with discipline-specific skills and knowledge as well as softer 'generic' skills. It also highlights the importance of formal 'work-based' learning within undergraduate curricula in providing students with the skills and experiences required by employers operating within a global workplace

Negative Autoregulation by Fas Stabilizes Adult Erythropoiesis and Accelerates Its Stress Response

Erythropoiesis maintains a stable hematocrit and tissue oxygenation in the basal state, while mounting a stress response that accelerates red cell production in anemia, blood loss or high altitude. Thus, tissue hypoxia increases secretion of the hormone erythropoietin (Epo), stimulating an increase in erythroid progenitors and erythropoietic rate. Several cell divisions must elapse, however, before Epo-responsive progenitors mature into red cells. This inherent delay is expected to reduce the stability of erythropoiesis and to slow its response to stress. Here we identify a mechanism that helps to offset these effects. We recently showed that splenic early erythroblasts, ‘EryA’, negatively regulate their own survival by co-expressing the death receptor Fas, and its ligand, FasL. Here we studied mice mutant for either Fas or FasL, bred onto an immune-deficient background, in order to avoid an autoimmune syndrome associated with Fas deficiency. Mutant mice had a higher hematocrit, lower serum Epo, and an increased number of splenic erythroid progenitors, suggesting that Fas negatively regulates erythropoiesis at the level of the whole animal. In addition, Fas-mediated autoregulation stabilizes the size of the splenic early erythroblast pool, since mutant mice had a significantly more variable EryA pool than matched control mice. Unexpectedly, in spite of the loss of a negative regulator, the expansion of EryA and ProE progenitors in response to high Epo in vivo, as well as the increase in erythropoietic rate in mice injected with Epo or placed in a hypoxic environment, lagged significantly in the mutant mice. This suggests that Fas-mediated autoregulation accelerates the erythropoietic response to stress. Therefore, Fas-mediated negative autoregulation within splenic erythropoietic tissue optimizes key dynamic features in the operation of the erythropoietic network as a whole, helping to maintain erythroid homeostasis in the basal state, while accelerating the stress response