Closed-cycle, low-vibration 4 K cryostat for ion traps and other applications

In-vacuo cryogenic environments are ideal for applications requiring both low temperatures and extremely low particle densities. This enables reaching long storage and coherence times for example in ion traps, essential requirements for experiments with highly charged ions, quantum computation, and optical clocks. We have developed a novel cryostat continuously refrigerated with a pulse-tube cryocooler and providing the lowest vibration level reported for such a closed-cycle system with 1 W cooling power for a <5 K experiment. A decoupling system suppresses vibrations from the cryocooler by three orders of magnitude down to a level of 10 nm peak amplitudes in the horizontal plane. Heat loads of about 40 W (at 45 K) and 1 W (at 4 K) are transferred from an experimental chamber, mounted on an optical table, to the cryocooler through a vacuum-insulated massive 120 kg inertial copper pendulum. The 1.4 m long pendulum allows installation of the cryocooler in a separate, acoustically isolated machine room. In the laser laboratory, we measured the residual vibrations using an interferometric setup. The positioning of the 4 K elements is reproduced to better than a few micrometer after a full thermal cycle to room temperature. Extreme high vacuum on the $10^{-15}$ mbar level is achieved. In collaboration with the Max-Planck-Intitut f\"ur Kernphysik (MPIK), such a setup is now in operation at the Physikalisch-Technische Bundesanstalt (PTB) for a next-generation optical clock experiment using highly charged ions

Seasonality and interannual variability of copepods in the Western English Channel, Celtic Sea, Bay of Biscay, and Cantabrian Sea with a special emphasis to Calanus helgolandicus and Acartia clausi

A total of five mesozooplankton time series data sets were assembled to compare the seasonal and interannual patterns of abundance of calanoid copepods in the Western English Channel (Station L4), Celtic Sea, Bay of Biscay (Continuous Plankton Recorder), and the Cantabrian Sea (RADIALES time series, Santander, St-4 and St-6) from January 1992 to December 1999. A strong seasonal component in taxonomic composition was detected at the locations considered. There was also a strong latitudinal effect on diversity at each location, southernmost locations being more diverse. The seasonal dynamics and year-to-year variability of two copepod species: Calanus helgolandicus and Acartia clausi were studied in detail. A latitudinal pattern in the seasonal cycles of both copepod species was observed. The peaks of both occur earlier in spring in the warmer southern region and move northwards, consistent with the temperature regimes at each location, supporting the broad concept that species occupy a thermal niche in time as well as in space. There was a strong degree of interannual variability between sites and between species. No clear trends, but some coherent events among data sets, reveal a regional response to environmental forcing factors. Correlations suggest possible connections with environmental indices like the North Atlantic Oscillation and the Gulf Stream North Wall index. There was a positive correlation between the NAO and the abundance of C. helgolandicus at station L4 off Plymouth; however, the relationship in the Celtic Sea and Bay of Biscay was opposite to that expected based on previous results. Despite the differences in the sampling techniques used within each dataset, the results are comparable and coherent in terms of taxonomic composition and the seasonal and interannual patterns detected

Algorithmic Ground-state Cooling of Weakly-Coupled Oscillators using Quantum Logic

Most ions lack the fast, cycling transitions that are necessary for direct laser cooling. In most cases, they can still be cooled sympathetically through their Coulomb interaction with a second, coolable ion species confined in the same potential. If the charge-to-mass ratios of the two ion types are too mismatched, the cooling of certain motional degrees of freedom becomes difficult. This limits both the achievable fidelity of quantum gates and the spectroscopic accuracy. Here we introduce a novel algorithmic cooling protocol for transferring phonons from poorly- to efficiently-cooled modes. We demonstrate it experimentally by simultaneously bringing two motional modes of a Be$^{+}$-Ar$^{13+}$ mixed Coulomb crystal close to their zero-point energies, despite the weak coupling between the ions. We reach the lowest temperature reported for a highly charged ion, with a residual temperature of only $T\lesssim200~\mathrm{\mu K}$ in each of the two modes, corresponding to a residual mean motional phonon number of $\langle n \rangle \lesssim 0.4$. Combined with the lowest observed electric field noise in a radiofrequency ion trap, these values enable an optical clock based on a highly charged ion with fractional systematic uncertainty below the $10^{-18}$ level. Our scheme is also applicable to (anti-)protons, molecular ions, macroscopic charged particles, and other highly charged ion species, enabling reliable preparation of their motional quantum ground states in traps

Cytometric Diversity of Marine Bacterioplankton: A 10 Years Interannual study In the Southern Bay of Biscay.

The application of molecular methods to marine ecology in the last decades has completely changed our view of the patterns of diversity and distribution of microorganisms in the ocean (Giovannoni et al. 1990, Zinger et al. 2012). However, these methods are expensive and time-consuming when applied on a large number of samples. Flow-cytometry, on the other hand, allows an efficient and rapid processing of a large number of samples. In this sense, the use of single-cell measurements by flow-cytometry for diversity purposes would be a great advance. In marine ecosystems, this concept has been introduced by Li 1997 as `cytometric diversity'. OBJECTIVES: In this study we evaluated the power of cytometric diversity to detect changes in the composition of bacterioplankton communities: Cant 1) By comparing changes in bacterial composition of 3.5 years surface samples obtained by cytometric diversity and molecular approaches. 2) Analysing the cytometric diversity patterns of a set of 10-years monthly bacterioplankton flow-cytometry samples for 3 coastal stations

Changes in population age-structure obscure the temperature-size rule in marine cyanobacteria

The temperature-size Rule (TSR) states that there is a negative relationship between ambient temperature and body size. This rule has been independently evaluated for different phases of the life cycle in multicellular eukaryotes, but mostly for the average population in unicellular organisms. We acclimated two model marine cyanobacterial strains (Prochlorococcus marinus MIT9301 and Synechococcus sp. RS9907) to a gradient of temperatures and measured the changes in population age-structure and cell size along their division cycle. Both strains displayed temperature-dependent diel changes in cell size, and as a result, the relationship between temperature and average cell size varied along the day. We computed the mean cell size of new-born cells in order to test the prediction of the TSR on a single-growth stage. Our work reconciles previous inconsistent results when testing the TSR on unicellular organisms, and shows that when a single-growth stage is considered the predicted negative response to temperature is revealed.Versión del edito

Experiencia de implementación de un proyecto Business Intelligence en una organización de salud privada de Argentina

La implementación de un proyecto de Business Intelligence (BI) es parte del proceso de crecimiento de una institución ya que permite optimizar los distintos procesos de atención y gestión convirtiéndola en una organización más eficiente y sustentable. El objetivo de esta presentación es compartir la experiencia adquirida durante la implementación de un proyecto de BI en una organización de salud del ámbito privado de Argentina, integrada por múltiples centros de atención, describiendo los métodos usados y principales resultados alcanzados. En la etapa inicial del proyecto, nos encontrábamos en un nivel de madurez de Gestión de Calidad de la Información (CDI) inicial, sin evaluación de la calidad de los datos y la información ni planteo de mejoras. En un año, a partir del cumplimiento de las etapas de trabajo propuestas, hemos alcanzado un nivel de Gestión de CDI integrado, teniendo un mejor conocimiento de los problemas, con capacidad de reacción y corrección ante la detección de errores. Actualmente, trabajamos activamente para alcanzar un nivel de madurez gestionado y optimizado, con evaluación y mejora continua de la CDI. Consideramos que compartir esta experiencia local podría ser valioso para otras instituciones que deseen iniciar el camino de la gestión basada en datos.Sociedad Argentina de Informática e Investigación Operativ

Temperature Responses of Heterotrophic Bacteria in Co-culture With a Red Sea Synechococcus Strain

Interactions between autotrophic and heterotrophic bacteria are fundamental for marine biogeochemical cycling. How global warming will affect the dynamics of these essential microbial players is not fully understood. The aims of this study were to identify the major groups of heterotrophic bacteria present in a Synechococcus culture originally isolated from the Red Sea and assess their joint responses to experimental warming within the metabolic ecology framework. A co-culture of Synechococcus sp. RS9907 and their associated heterotrophic bacteria, after determining their taxonomic affiliation by 16S rRNA gene sequencing, was acclimated and maintained in the lab at different temperatures (24–34°C). The abundance and cellular properties of Synechococcus and the three dominant heterotrophic bacterial groups (pertaining to the genera Paracoccus, Marinobacter, and Muricauda) were monitored by flow cytometry. The activation energy of Synechococcus, which grew at 0.94–1.38 d–1, was very similar (0.34 ± 0.02 eV) to the value hypothesized by the metabolic theory of ecology (MTE) for autotrophs (0.32 eV), while the values of the three heterotrophic bacteria ranged from 0.16 to 1.15 eV and were negatively correlated with their corresponding specific growth rates (2.38–24.4 d–1). The corresponding carrying capacities did not always follow the inverse relationship with temperature predicted by MTE, nor did we observe a consistent response of bacterial cell size and temperature. Our results show that the responses to future ocean warming of autotrophic and heterotrophic bacteria in microbial consortia might not be well described by theoretical universal rules

The use of LA-ICP-MS in a pilot study for determining the concentration of selected trace elements in rudist shells

ABSTRACT A protocol for the determination of the concentration of selected elements in two rudist shells was developed using Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Element analysis in rudists has never been performed beyond including major and some minor elements, and thus this work presents the first results in this field. The concentrations of 35 isotopes were analyzed. Low iron and manganese concentrations reflect the absence of a diagenetical imprint on both shells. There is a negligible amount of crust-associated elements, which reveal little evidence of terrigenous input. Phosphorus amount is also low; however, it is high enough to mask reliable Rare Earth + Yttrium (REY) pattern measurements. Strontium and magnesium concentrations in the inner layers of a shell of Titanosarcolites show relicts of an original aragonitic composition. On the contrary, concentrations of these elements in a shell of Biradiolites rudissimus reveal an original low Mg-calcite mineralogy in its outer layers. The two shells were selected, considering their apparently a priori good preservation, based on the petrological examination of thin sections. No significant concentrations of elements such as chromium, cobalt, nickel, copper, zinc, molybdenum or antimony could be found. The concentrations of vanadium and barium may reflect evidence of biological activity, since they apparently do not correlate significantly with silicon, aluminium or sulphur. The low cost and precision of this method in comparison to others such as the use of electron microprobe, or X-ray fluorescence, makes it an optimum alternative for geochemical analyses of fossils, thus opening a new line of research. Keywords: Cretaceous, geochemistry, LA-ICP-MS, rudists, trace elements. El uso de LA-ICP-MS RESUMEN EXTENDIDO EN CASTELLANO Introducción y Metodología Los Rudistas son moluscos bivalvos sésiles extintos que dominaron los ambientes arrecifales del Jurásico Superior hasta el Cretácico Superior En todos los casos, la exactitud de los resultados ha sido atribuida a la escasa diagénesis como producto de la mineralogía de las conchas (calcita baja en magnesio). En investigaciones más recientes, Hennhöfer y colaboradores (2012) llevaron a cabo análisis de isótopos de oxígeno en conchas seleccionadas de rudistas dentro de un pequeño bouquet de la especie . Muy pocos son los trabajos que abordan aspectos geoquímicos mediante LA-ICP-MS en fósiles provenientes de facies carbonatadas (Burla et al., 2009; Evans and Müller, 2013), pero ninguno lo ha hecho con rudistas. Esta es la razón por la cual decidimos proponer este protocolo. Dos secciones pulidas provenientes de valvas inferiores de conchas de rudistas fueron analizadas. Estas conchas pertenecen a un ejemplar de &quot;Titanosarcolites sp.nov. 1 pendiente de denominación&quot; Oviedo-García del Maastrichtiense de Chiapas, México (Figura 1), y a un ejemplar de Biradiolites rudissimus Trechmann del Campaniense?-Maastrichtiense, también de Chiapas, México (Figura 2). La selección de las conchas fue llevada a cabo a través del análisis petrológico de láminas delgadas, entre cinco conchas del género Titanosarcolites y tres del género Biradiolites La ablación con láser se realizó utilizando un sistema Excimer de 193 nm COMPEX 110 (Lambda Physik, Göttingen, Alemania) Sánchez-Beristain, F. et al., 2015. The use of LA-ICP-MS in a pilot study for determining... Boletín Geológico y Minero, 160 Sánchez-Beristain, F. et al., 2015. The use of LA-ICP-MS in a pilot study for determining... Boletín Geológico y Minero, 126 Resultados y Discusión Los resultados observados para ambas conchas son similares en cierta medid

Evaluation of processed and ultra-processed foods: An analysis before the implementation of front-of-package labeling in Peru

Objective. The objective of the current study was to evaluate critical nutrients of industrialized foods and compare them with the technical parameters established in the Peruvian regulations, in its two stages of implementation, referring to front-of-package labeling before the beginning of its validity in June 2019. Methods. Cross-sectional study in which the critical nutrients of sodium, total sugar, saturated fat and transfat were analyzed from data declared in the nutritional labels of 511 processed and ultra-processed foods that were part of the products purchased for the consumption of 88 families of students from one private university in Lima. The technical parameters used to evaluate the critical nutrients are those established in the Regulation of Law 30021. All analyses were carried out with Excel and SPSS version 21, Student’s t-statistics and McNemar’s test were used. Results. 79 processed foods and 432 ultra-processed foods were analyzed. Of the total processed and ultra-processed products evaluated, it was found that for sodium 14.3% and 37.2% respectively exceeded the parameters in the first and second stages established in the regulations; for sugar 54.2% and 62.6%; while for saturated fats 52.8% and 59.5%, respectively. Solid foods are those that will have the greatest changes in front labeling between the first and second stages of implementation, unlike liquids that without changing the composition of their products, their front labeling would not vary significantly. Conclusions. The saturated fat present in solid products (processed and ultra-processed), exceeds the parameters in both stages of implementation in most products. Of the foods compared, regardless of type and category, the critical nutrient sugar was the one that was highly present in most of the products evaluated for the first and second stages of implementation.Revisión por pare

More, smaller bacteria in response to ocean's warming?

Heterotrophic bacteria play a major role in organic matter cycling in the ocean. Although the high abundances and relatively fast growth rates of coastal surface bacterioplankton make them suitable sentinels of global change, past analyses have largely overlooked this functional group. Here, time series analysis of a decade of monthly observations in temperate Atlantic coastal waters revealed strong seasonal patterns in the abundance, size and biomass of the ubiquitous flow-cytometric groups of low (LNA) and high nucleic acid (HNA) content bacteria. Over this relatively short period, we also found that bacterioplankton cells were significantly smaller, a trend that is consistent with the hypothesized temperature-driven decrease in body size. Although decadal cell shrinking was observed for both groups, it was only LNA cells that were strongly coherent, with ecological theories linking temperature, abundance and individual size on both the seasonal and interannual scale. We explain this finding because, relative to their HNA counterparts, marine LNA bacteria are less diverse, dominated by members of the SAR11 clade. Temperature manipulation experiments in 2012 confirmed a direct effect of warming on bacterial size. Concurrent with rising temperatures in spring, significant decadal trends of increasing standing stocks (3% per year) accompanied by decreasing mean cell size (-1% per year) suggest a major shift in community structure, with a larger contribution of LNA bacteria to total biomass. The increasing prevalence of these typically oligotrophic taxa may severely impact marine food webs and carbon fluxes by an overall decrease in the efficiency of the biological pump.Versión del editor5,064