Mid-Infrared Instrumentation for the European Extremely Large Telescope

MIDIR is the proposed thermal/mid-IR imager and spectrograph for the European Extremely Large Telescope (E-ELT). It will cover the wavelength range of 3 to at least 20 microns. Designed for diffraction-limited performance over the entire wavelength range, MIDIR will require an adaptive optics system; a cryogenically cooled system could offer optimal performance in the IR, and this is a critical aspect of the instrument design. We present here an overview of the project, including a discussion of MIDIR's science goals and a comparison with other infrared (IR) facilities planned in the next decade; top level requirements derived from these goals are outlined. We describe the optical and mechanical design work carried out in the context of a conceptual design study, and discuss some important issues to emerge from this work, related to the design, operation and calibration of the instrument. The impact of telescope optical design choices on the requirements for the MIDIR instrument is demonstrated.Comment: for publication in SPIE Proceedings vol. 6692, Cryogenic Optical Systems and Instrumentation XII, eds. J.B. Heaney and L.G. Burriesci, San Diego, Aug 200

Quantum Conductance Steps in Solutions of Multiwalled Carbon Nanotubes

We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a mixture of polychlorinated biphenyls. The solutions are stable at room temperature. Transport measurements were performed using a scanning--tunneling probe on a sample prepared by spin--coating of the solution on gold substrates. Conductance steps were clearly seen. An histogram of a high number of traces shows maximum peaks at integer values of the conductance quantum $G_0 = 2e^2/h$, demonstrating ballistic transport at room temperature along the carbon nanotube over distances longer than $1.4\mu m$.Comment: 4 pages and 2 figure

Measurement of the dynamic charge response of materials using low-energy, momentum-resolved electron energy-loss spectroscopy (M-EELS)

One of the most fundamental properties of an interacting electron system is its frequency- and wave-vector-dependent density response function, $\chi({\bf q},\omega)$. The imaginary part, $\chi''({\bf q},\omega)$, defines the fundamental bosonic charge excitations of the system, exhibiting peaks wherever collective modes are present. $\chi$ quantifies the electronic compressibility of a material, its response to external fields, its ability to screen charge, and its tendency to form charge density waves. Unfortunately, there has never been a fully momentum-resolved means to measure $\chi({\bf q},\omega)$ at the meV energy scale relevant to modern elecronic materials. Here, we demonstrate a way to measure $\chi$ with quantitative momentum resolution by applying alignment techniques from x-ray and neutron scattering to surface high-resolution electron energy-loss spectroscopy (HR-EELS). This approach, which we refer to here as "M-EELS," allows direct measurement of $\chi''({\bf q},\omega)$ with meV resolution while controlling the momentum with an accuracy better than a percent of a typical Brillouin zone. We apply this technique to finite-q excitations in the optimally-doped high temperature superconductor, Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi2212), which exhibits several phonons potentially relevant to dispersion anomalies observed in ARPES and STM experiments. Our study defines a path to studying the long-sought collective charge modes in quantum materials at the meV scale and with full momentum control.Comment: 26 pages, 10 sections, 7 figures, and an appendi

Subband population in a single-wall carbon nanotube diode

We observe current rectification in a molecular diode consisting of a semiconducting single-wall carbon nanotube and an impurity. One half of the nanotube has no impurity, and it has a current-voltage (I-V) charcteristic of a typical semiconducting nanotube. The other half of the nanotube has the impurity on it, and its I-V characteristic is that of a diode. Current in the nanotube diode is carried by holes transported through the molecule's one-dimensional subbands. At 77 Kelvin we observe a step-wise increase in the current through the diode as a function of gate voltage, showing that we can control the number of occupied one-dimensional subbands through electrostatic doping.Comment: to appear in Physical Review Letters. 4 pages & 3 figure

Review of 14 drowning publications based on the Utstein style for drowning

Abstract Background The Utstein style for drowning (USFD) was published in 2003 with the aim of improving drowning research. To support a revision of the USFD, the current study aimed to generate an inventory of the use of the USFD parameters and compare the findings of the publications that have used the USFD. Methods A search in Pubmed, Embase, the Cochrane Library, Web of Science and Scopus was performed to identify studies that used the USFD and were published between 01-10-2003 and 22-03-2015. We also searched in Pubmed, Embase, the Cochrane Library, Web of Science, and Scopus for all publications that cited the two publications containing the original ILCOR advisory statement introducing and recommending the USFD. In total we identified 14 publications by groups that explicitly used elements of the USFD for collecting and reporting their data. Results Of the 22 core and 19 supplemental USFD parameters, 6–19 core (27–86%) and 1–12 (5–63%) supplemental parameters were used; two parameters (5%) have not been used in any publication. Associations with outcome were reported for nine core (41%) and five supplemental (26%) USFD parameters. The USFD publications also identified non-USFD parameters related to outcome: initial cardiac rhythm, time points and intervals during resuscitation, intubation at the drowning scene, first hospital core temperature, serum glucose and potassium, the use of inotropic/vasoactive agents and the Paediatric Index of Mortality 2-score. Conclusions Fourteen USFD based drowning publications have been identified. These publications provide valuable information about the process and quality of drowning resuscitation and confirm that the USFD is helpful for a structured comparison of the outcome of drowning resuscitation

Evaluatie van vrijstellingen voor de landbouw in de overdrachtsbelasting

In dit rapport wordt een zestal voor de agrarische sector relevante vrijstellingen in artikel 15, eerste lid van de Wet op belastingen van Rechtsverkeer (WBR) geëvalueerd. De vrijstellingen zorgen ervoor dat de aankoop van landbouwgrond onder bepaalde voorwaarden onbelast is met 6% overdrachtsbelasting. In de evaluatie wordt per vrijstelling onderzocht of de regeling op een doeltreffende en doelmatige manier leidt tot het bereiken van de geformuleerde doelstellingen. Daarnaast wordt aandacht besteed aan de neveneffecten van de regeling

Surviving the storm:manual vs. mechanical chest compressions onboard a lifeboat during bad weather conditions

Objective: It is challenging for rescuers to perform cardiopulmonary resuscitation (CPR) onboard lifeboats, particularly during rough weather. A mechanical chest compression device (MCD) may provide better quality chest compressions. The aim of this study was to compare the quality of chest compressions performed by lifeboat-crewmembers with those of a MCD during rough-sea conditions.Methods: Lifeboat-crewmembers were scheduled to provide compression-onlyCPR on a resuscitation-mannequin during two sets of five 6-min epochs on alifeboat at sea in two different weather-conditions. Simultaneously a MCD wasused for compression-only CPR on another mannequin onboard the lifeboat. Ona third occasion compressions by MCD only were measured due to COVID-19restrictions. The primary outcome variable was the quality of chest compression,evaluated using published variables and standards (mean compression depthand compression frequency, percentage correct compression depth, percentageof not leaning on the thorax, percentage of correct hand placement on thethorax, hands-off-time).Results: Six male lifeboat-crewmembers (mean age 35 years) performed CPRduring two different weather conditions. In weather-conditions one (wind∼6–7 Beaufort/wave-height: 100–150 cm) quality of manual compressions wassignificantly worse than mechanical compressions for mean compression depth(p < 0.05) and compression frequency (p < 0.05), percentage correct compression depth (p < 0.05), percentage of not leaning on the thorax (p < 0.05), and hands off time (p < 0.05). Crewmembers could only perform CPR for a limited time-period (sea-conditions/seasickness) and after one set of five epochs measurements were halted. In weather-condition two (wind ∼9 Beaufort/wave-height ∼200 cm) similar results were found during two epochs, after which measurements were halted (sea-conditions/seasickness). In weather-condition three (wind ∼7 Beaufort/wave-height ∼300–400 cm) MCD compressions were according to resuscitation-guidelines except for three epochs during which the MCD was displaced.Conclusion: Crewmembers were only able to perform chest-compressions for alimited time because of the weather-conditions. The MCD was able to providegood quality chest compressions during all but three epochs during the studyperiod. More research is needed to determine whether MCD-use in real-lifecircumstances improves outcome. Inclusion of data on use of a MCD on lifeboatsshould be considered in future revisions of the USFD and resuscitation guidelines

Bioconversion of polyphenols and organic acids by gut microbiota of predigested Hibiscus sabdariffa L. calyces and Agave (A. tequilana Weber) fructans assessed in a dynamic in vitro model (TIM-2) of the human colon

The present work aimed at understanding gut microbiota bioconversion of phenolic compounds (PC) and organic acids in predigested Hibiscus sabdariffa (Hb) calyces and the mixture of Hb and Agave (Agave tequilana Weber) fructans (AF). With this purpose, dried Hb and Hb/AF were predigested with enzymatic treatment, and then fermented in a dynamic in vitro model of the human colon (TIM-2). After HPLC-ESI-QToF-MS analysis of samples taken at 0, 24, 48 and 72 h of fermentation, it was observed that hydroxycinnamic acids, flavanols, flavonols, and anthocyanins were mainly transformed into derivatives of hydroxyphenylpropionic, hydroxyphenylacetic and hydroxybenzoic acids. Moreover, organic acids, such as hydroxycitric and hibiscus acids, were formed along with unidentified lactones and reduced compounds. Interestingly, no differences were observed between microbial-derived metabolites formed after the fermentation of Hb and Hb/AF. In conclusion, colonic fermentation of polyphenol-rich Hb yields a wide range of microbial phenolic metabolites with potential effects on health.RMB and SGSA acknowledge to Science and Technology for Development Program (CYTED) through the Ibero-American Network of Underutilized Autonomous Foods (ALSUB-CYTED, 118RT0543). SGSA acknowledges CONACYT-Mexico for the sabbatical grant 260935. The Spanish Ministry of Science, Innovation and Universities (Project AGL2015-69986-R) is also acknowledged. This research has been made possible with the support of the Dutch Province of Limburg.Peer reviewe