Scalable arrays of micro-Penning traps for quantum computing and simulation

We propose the use of 2-dimensional Penning trap arrays as a scalable platform for quantum simulation and quantum computing with trapped atomic ions. This approach involves placing arrays of micro-structured electrodes defining static electric quadrupole sites in a magnetic field, with single ions trapped at each site and coupled to neighbors via the Coulomb interaction. We solve for the normal modes of ion motion in such arrays, and derive a generalized multi-ion invariance theorem for stable motion even in the presence of trap imperfections. We use these techniques to investigate the feasibility of quantum simulation and quantum computation in fixed ion lattices. In homogeneous arrays, we show that sufficiently dense arrays are achievable, with axial, magnetron and cyclotron motions exhibiting inter-ion dipolar coupling with rates significantly higher than expected decoherence. With the addition of laser fields these can realize tunable-range interacting spin Hamiltonians. We also show how local control of potentials allows isolation of small numbers of ions in a fixed array and can be used to implement high fidelity gates. The use of static trapping fields means that our approach is not limited by power requirements as system size increases, removing a major challenge for scaling which is present in standard radio-frequency traps. Thus the architecture and methods provided here appear to open a path for trapped-ion quantum computing to reach fault-tolerant scale devices.Comment: 21 pages, 10 figures Changes include adding section IX (Implementation Example) and substantially rewriting section X (Scaling

De la biografía a la prosopografía: los parlamentarios de los distritos de Vasconia en la II República española (1931-1939)

Having carried out a micro-biographical analysis, using primary sources, of the 610 parliamentarians who represented the Basque districts between 1808 and 1939 in successive biographical dictionaries, we now undertake a prosopographical analysis of 44 parliamentarians who represented the districts of the Basque Country in the Spanish II Republic (1931-1939). Aspects covered include: geographical origin, age, life expectancy, educational and professional profile, cultural level and sociability, continuity in political activity between the Monarchy and the Republic. The work offers novel comparative conclusions.Realizado un análisis microbiográfico, con fuentes primarias, de los 610 parlamentarios que representaron a los distritos vascos entre 1808 y 1939 en sucesivos diccionarios biográficos, abordamos el análisis prosopográfico de los 44 parlamentarios que representaron a los distritos de Vasconia en la II República española (1931-1939): origen geográfico, edad, esperanza de vida, perfil educativo y profesional, nivel cultural y sociabilidad, continuidad en la actividad política entre la Monarquía y la República. El trabajo ofrece conclusiones comparativas novedosas

Identification of loci associated with pathological outcomes in Holstein cattle infected with Mycobacterium avium subsp. paratuberculosis using whole-genome sequence data

[EN]Bovine paratuberculosis (PTB), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is a chronic granulomatous enteritis that affects cattle worldwide. According to their severity and extension, PTB-associated histological lesions have been classified into the following groups; focal, multifocal, and diffuse. It is unknown whether these lesions represent sequential stages or divergent outcomes. In the current study, the associations between host genetic and pathology were explored by genotyping 813 Spanish Holstein cows with no visible lesions (N = 373) and with focal (N = 371), multifocal (N = 33), and diffuse (N = 33) lesions in gut tissues and regional lymph nodes. DNA from peripheral blood samples of these animals was genotyped with the bovine EuroG MD Bead Chip, and the corresponding genotypes were imputed to whole-genome sequencing (WGS) data using the 1000 Bull genomes reference population. A genome-wide association study (GWAS) was performed using the WGS data and the presence or absence of each type of histological lesion in a case-control approach. A total of 192 and 92 single nucleotide polymorphisms (SNPs) defining 13 and 9 distinct quantitative trait loci (QTLs) were highly-associated (P <= 5 x 10(-7)) with the multifocal (heritability = 0.075) and the diffuse (heritability = 0.189) lesions, respectively. No overlap was seen in the SNPs controlling these distinct pathological outcomes. The identified QTLs overlapped with some QTLs previously associated with PTB susceptibility, bovine tuberculosis susceptibility, clinical mastitis, somatic cell score, bovine respiratory disease susceptibility, tick resistance, IgG level, and length of productive life. Pathway analysis with candidate genes overlapping the identified QTLs revealed a significant enrichment of the keratinization pathway and cholesterol metabolism in the animals with multifocal and diffuse lesions, respectively. To test whether the enrichment of SNP variants in candidate genes involved in the cholesterol metabolism was associated with the diffuse lesions; the levels of total cholesterol were measured in plasma samples of cattle with focal, multifocal, or diffuse lesions or with no visible lesions. Our results showed reduced levels of plasma cholesterol in cattle with diffuse lesions. Taken together, our findings suggested that the variation in MAP-associated pathological outcomes might be, in part, genetically determined and indicative of distinct host responses.Financial support for this study was provided by a Grant from the Spanish Ministry of Science, Innovation, and Universities (RTI2018-094192-R-C21) and by European Regional Development Funds (FEDER) to MAH. MC and GBB have been awarded fellowships from the National Institute for Agricultural Research (INIA) and the Spanish Ministry of Science, Innovation and Universities programs, respectively. This work has been possible thanks to the support of the computing infrastructure of the i2BASQUE Research and Academic Network. We gratefully acknowledge the Bull Genomes Consortium for providing accessibility to the WGS data that was used in this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

MaRCoS, an open-source electronic control system for low-field MRI

Every magnetic resonance imaging (MRI) device requires an electronic control system that handles pulse sequences and signal detection and processing. Here we provide details on the architecture and performance of MaRCoS, a MAgnetic Resonance COntrol System developed by an open international community of low-field MRI researchers. MaRCoS is inexpensive and can handle cycle-accurate sequences without hard length limitations, rapid bursts of events, and arbitrary waveforms. It can also be easily adapted to meet further specifications required by the various academic and private institutions participating in its development. We describe the MaRCoS hardware, firmware and software that enable all of the above, including a Python-based graphical user interface for pulse sequence implementation, data processing and image reconstruction.Comment: 10 pages, 4 figure

The first comprehensive micro use-wear analysis of an early Acheulean assemblage (Thiongo Korongo, Olduvai Gorge, Tanzania)

Probably, one of the biggest questions about the Acheulean is focused on the functional aspects of its lithic industry and, more specifically, its link to subsistence activities developed by hominins during the Early Stone Age. Historically, tecno-functional research on ESA techno-complex has focused on the role played by flakes and LCT in the processing of animal carcasses, but less attention has been payed to other possible activities related with subsistence and tool making. Previous traceological studies on African Lower Paleolithic lithic industries have shown the complexity of activities made with the earliest lithic tools, including not only the processing of animal carcasses, but also activities dedicated to processing wood, non-woody plants and underground storage organs (USOs). In this paper we present the use-wear results obtained from the analysis of the Early Acheulean lithic tools with potentially functional edges which are part of the lithic assemblage from the Thiongo Korongo archaeological site (TK) (Olduvai Gorge, Tanzania). The three main levels of the archaeological site, TKSF, TKLSC and TKLF, have been used as samples. From 466 lithic artefacts analyzed, 16 pieces present sufficient preservation of use related traces that are able to clearly identify the activities developed when compared with experimental reference collections. As a result, we have identified activities mainly related with the cutting and scraping of wood and non-woody plants, including USOs. In addition, some pieces have also presented traces indicating the processing of animal carcasses. These data provides important information about different activities developed in TK by early hominids, allowing us to make broader inferences about the different subsistence activities carried out during the Acheulean in Eastern Africa.Depto. de Prehistoria, Historia Antigua y ArqueologíaFac. de Geografía e HistoriaTRUEMinisterio de Ciencia e Innovación (MICINN)pu

Identification of loci associated with susceptibility to Mycobacterium avium subsp. paratuberculosis infection in Holstein cattle using combinations of diagnostic tests and imputed whole-genome sequence data

Bovine paratuberculosis (PTB) is a chronic inflammatory disease caused by Mycobacterium avium susbp. paratuberculosis (MAP). Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) significantly associated with susceptibility to bovine PTB. The main objective of this study was to identify quantitative trait loci (QTLs) associated with MAP infection in Spanish Holstein cows (N = 983) using combinations of diagnostic tests and imputed whole-genome sequence (WGS) data. The infection status of these animals was defined by three diagnostic methods including ELISA for MAP-antibodies detection, and tissue culture and PCR for MAP detection. The 983 cows included in this study were genotyped with the Bovine MD SNP50 Bead Chip, and the corresponding genotypes were imputed to WGS using the 1,000 Bull genomes reference population. In total, 33.77 million SNP variants per animal were identified across the genome. Linear mixed models were used to calculate the heritability (h2) estimates for each diagnostic test and test combinations. Next, we performed a case-control GWAS using the imputed WGS datasets and the phenotypes and combinations of phenotypes with h2 estimates > 0.080. After performing the GWAS, the test combinations that showed SNPs with a significant association (PFDR ≤ 0.05), were the ELISA-tissue PCR-tissue culture, ELISA-tissue culture, and ELISA-tissue PCR. A total of twelve quantitative trait loci (QTLs) highly associated with MAP infection status were identified on the Bos taurus autosomes (BTA) 4, BTA5, BTA11, BTA12, BTA14, BTA23, BTA24, and BTA28, and some of these QTLs were linked to immune-modulating genes. The identified QTLs on BTA23 spanning from 18.81 to 22.95 Mb of the Bos taurus genome overlapped with several QTLs previously found to be associated with PTB susceptibility, bovine tuberculosis susceptibility, and clinical mastitis. The results from this study provide more clues regarding the molecular mechanisms underlying susceptibility to PTB infection in cattle and might be used to develop national genetic evaluations for PTB in Spain.Financial support for this study was provided by a grant from the Spanish Ministry of Science, Innovation, and Universities (MICINN, project code: RTI2018-094192-R-C21) and by European Regional Development Funds (FEDER) to MAH. MC and GBB have been awarded fellowships from the National Institute for Agricultural Research (INIA) and MICINN, respectivel

All-solid-state continuous-wave laser systems for ionization, cooling and quantum state manipulation of beryllium ions

We describe laser systems for photoionization, Doppler cooling, and quantum state manipulation of beryllium ions. For photoionization of neutral beryllium, we have developed a continuous-wave 235nm source obtained by two stages of frequency doubling from a diode laser at 940nm. The system delivers up to 400 mW at 470nm and 28 mW at 235nm. For control of the beryllium ion, three laser wavelengths at 313nm are produced by sum-frequency generation and second-harmonic generation from four infrared fiber lasers. Up to 7.2 W at 626nm and 1.9 W at 313nm are obtained using two pump beams at 1051 and 1551nm. Intensity drifts of around 0.5% per hour have been measured over 8h at a 313nm power of 1W. These systems have been used to load beryllium ions into a segmented ion trap

Functional analysis of Acheleuan lithic industry of Thiongo Korongo (Olduvai Gorge, Tanzania): the case study for flakes and bifaces

In this paper we will present an ongoing research about the function of Acheulean flakes and LTC´s recovered at Thiongo Korongo (TK) (Upper section of Olduvai’s Bed II, ca. 1.353 ± 0.035 Ma.). Our hypothesis is that these assemblages could reflect actual evidence of various activities developed at the site other than knapping. The presence of faunal remains, including different species of large mammals, suggest that butchery and carcass processing activities could potentially have been realized there. The variability of formats and tools present support the idea that other activities (e.g. wood working, digging, tuber / vegetable processing, etc.) could also have been performed at the site. These hypotheses are relevant to our understanding of the extent of activities that took place during the Acheulean and the function, technological variability and the settlement dynamics of the site