Results from MINOS and NOvA Backhouse, C
Journal of physics. Conference series,
04/2015, Letnik:
598, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The MINOS experiment, operating in the NuMI beam since 2005, has provided the most precise measurement of the atmospheric mass splitting |Δm232|, and the recent combination of the vμ, ve, and ...atmospheric neutrino samples has provided some evidence of non-maximal mixing, and hints about the neutrino mass hierarchy and the θ23 octant. Construction of the NOvA experiment, situated off-axis in the upgraded NuMI beam, is almost complete. Over the coming years it will have significant power to probe the questions of the mass hierarchy, θ23 octant, and the possibility of CP violation in the lepton sector. This paper gives an overview of the results from MINOS, and of the sensitivity of the NOνA experiment.
Dental care professionals (DCPs) are thought to be at enhanced risk of occupational exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, robust data to support this from ...large-scale seroepidemiological studies are lacking. We report a longitudinal seroprevalence analysis of antibodies to SARS-CoV-2 spike glycoprotein, with baseline sampling prior to large-scale practice reopening in July 2020 and follow-up postimplementation of new public health guidance on infection prevention control (IPC) and enhanced personal protective equipment (PPE). In total, 1,507 West Midlands DCPs were recruited into this study in June 2020. Baseline seroprevalence was determined using a combined IgGAM enzyme-linked immunosorbent assay and the cohort followed longitudinally for 6 mo until January/February 2021 through the second wave of the coronavirus disease 2019 pandemic in the United Kingdom and vaccination commencement. Baseline seroprevalence was 16.3%, compared to estimates in the regional population of 6% to 7%. Seropositivity was retained in over 70% of participants at 3- and 6-mo follow-up and conferred a 75% reduced risk of infection. Nonwhite ethnicity and living in areas of greater deprivation were associated with increased baseline seroprevalence. During follow-up, no polymerase chain reaction–proven infections occurred in individuals with a baseline anti–SARS-CoV-2 IgG level greater than 147.6 IU/ml with respect to the World Health Organization international standard 20-136. After vaccination, antibody responses were more rapid and of higher magnitude in those individuals who were seropositive at baseline. Natural infection with SARS-CoV-2 prior to enhanced PPE was significantly higher in DCPs than the regional population. Natural infection leads to a serological response that remains detectable in over 70% of individuals 6 mo after initial sampling and 9 mo from the peak of the first wave of the pandemic. This response is associated with protection from future infection. Even if serological responses wane, a single dose of the Pfizer-BioNTech 162b vaccine is associated with an antibody response indicative of immunological memory.
It has long been recognized that one of the most important tasks for any organization to cope with is uncertainties. However, uncertainty in the business environment has still been the main cause of ...failure in industry. The paper investigates the role of postponement in the management of uncertainty. The concept of postponement is developed to include product development postponement, purchasing postponement, production postponement and logistics postponement. These postponement strategies are all presented to cope with different levels of uncertainty. Finally, conclusions are drawn and some remarks about further research are made.
The NOvA simulation chain Aurisano, A; Backhouse, C; Hatcher, R ...
Journal of physics. Conference series,
12/2015, Letnik:
664, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The NOνA experiment is a two-detector, long-baseline neutrino experiment operating in the recently upgraded NuMI muon neutrino beam. Simulating neutrino interactions and backgrounds requires many ...steps including: the simulation of the neutrino beam flux using FLUKA and the FLUGG interface; cosmic ray generation using CRY; neutrino interaction modeling using GENIE; and a simulation of the energy deposited in the detector using GEANT4. To shorten generation time, the modeling of detector-specific aspects, such as photon transport, detector and electronics noise, and readout electronics, employs custom, parameterized simulation applications. We will describe the NOνA simulation chain, and present details on the techniques used in modeling photon transport near the ends of cells, and in developing a novel data-driven noise simulation. Due to the high intensity of the NuMI beam, the Near Detector samples a high rate of muons originating in the surrounding rock. In addition, due to its location on the surface at Ash River, MN, the Far Detector collects a large rate (˜ 140 kHz) of cosmic muons. We will discuss the methods used in NOνA for overlaying rock muons and cosmic ray muons with simulated neutrino interactions and show how realistically the final simulation reproduces the preliminary NOνA data.
The NuMI Off-axis Neutrino Experiment (NOvA) is designed to study neutrino oscillations in the NuMI beam at Fermilab. Neutrinos at the Main Injector (NuMI) is currently being upgraded to provide 700 ...kW for NOvA. A 14 kt Far Detector in Ash River, MN and a functionally identical 0.3 kt Near Detector at Fermilab are positioned 810 km apart in the NuMI beam line. The fine granularity of the NOvA detectors provides a detailed representation of particle trajectories. The data volume associated with such granularity, however, poses problems for analyzing data with ease and speed. NOvA has developed a data summary file structure which discards the full event record in favor of higher-level reconstructed information. A general- purpose framework for neutrino oscillation measurements has been developed for analysis of these data summary files. We present the design methodology for this new file format as well as the analysis framework and the role it plays in producing NOvA physics results.
In this paper we demonstrate a new method for microfabricating PDMS devices that controls vapour diffusion, thereby reducing water loss at elevated temperatures and greatly increasing the reliability ...of the PCR. In the past, the vapour and liquid diffusion properties of the PDMS material in microfluidic devices have impaired performance. We show that this water loss is primarily due to vapour diffusion from the PDMS biochip and by implanting a polyethylene vapour barrier layer in the PDMS, the overall fluid loss was almost eliminated (reduced by a factor of 3). We have also developed a procedure to ensure irreversible bonding between the PDMS and the implant. With this improved microfabrication method we demonstrate the feasibility and advantages of performing small volume PCR genetic amplification (i.e. with less than 2
μl of PCR sample) within a PDMS–glass hybrid biochip. Diaphragm pumps and pinch-off valves were integrated in the system and these enabled fluid retention during the amplification stage and will facilitate higher levels of on-chip automation.
We present a novel method for fluorescence-based indirect detection of analytes and demonstrate its use for label-free detection of chemical toxins in a hand-held device. We fluorescently label a ...mixture of low-concentration carrier ampholytes and introduce it into an isotachophoresis (ITP) separation. The carrier ampholytes provide a large number of fluorescent species with a wide range of closely spaced effective electrophoretic mobilities. Analytes focus under ITP and displace subsets of these carrier ampholytes. The analytes are detected indirectly and quantified by analyzing the gaps in the fluorescent ampholyte signal. The large number (on the order of 1000) of carrier ampholytes enables detection of a wide range of analytes, requiring little a priori knowledge of their electrophoretic properties. We discuss the principles of the technique and demonstrate its use in the detection of various analytes using a standard microscope system. We then present the integration of the technique into a self-contained hand-held device and demonstrate detection of chemical toxins (2-nitrophenol and 2,4,6-trichlorophenol) in tap water, with no sample preparation steps.
Ferrofluid-based microchip pump and valve Hartshorne, Herb; Backhouse, Christopher J; Lee, William E
Sensors and actuators. B, Chemical,
05/2004, Letnik:
99, Številka:
2
Journal Article
Recenzirano
Fluid control is a key element in the performance of microfluidic “lab-on-a-chip” devices. The development of integrated multi-function micro-chemical reactors and analysis platforms depends upon ...on-chip valving and pumping. In this work, microfluidic valves and pumps were fabricated from etched glass substrates each bonded to a second glass substrate lid that had ultrasonically drilled access holes. The devices contained ferrofluid plugs of approximately 10
mm in length that were actuated by external magnets. The ferrofluid used in the devices was a colloidal suspension of ferromagnetic particles in a hydrophobic fluorocarbon carrier and was immiscible in water. With air in the channels, ferrofluid devices could withstand pressures of 12
kPa and could be opened and closed against pressures of 8.5 and 5.0
kPa, respectively, under a magnetic field of 2.8
kG. A ferrofluid pump comprising a ferrofluid piston and two ferrofluid valves was able to generate air pressures in excess of 5
kPa. In untreated glass channels, leakage of water around ferrofluid seals was significant. However, when the portions of the channel network that contained the ferrofluid were coated with a hydrophobic organo-silane, leakage was not detectable.
► Low-cost, thermally stable metal films were patterned on a photo-polymer. ► Presented a method for treating aluminum film on KMPR to stabilize resistivity. ► We demonstrate the film's suitability ...as heaters/sensors for LOC applications. ► Exceptional adhesion shown between sputtered aluminum and KMPR. ► High stability and linearity of resistivity from 22 to 165°C for 6h is achieved.
Polymers offer many advantageous physical properties as structural materials for MEMS and microfluidics. Additionally, polymers support rapid and inexpensive fabrication methods. Patterning metals on polymer microstructures is, however, much more challenging than doing so on conventional substrates such as silicon or glass. As a result, metal layers within polymeric devices are typically fabricated on non-polymeric substrates, and the polymer layers are then fabricated on top, which greatly constrains the variety of structures that can be built. A wider range of devices could be fabricated if there was a reliable method for producing and patterning stable metal films on a photo-polymer. Lab-on-chip (LOC) systems in particular would benefit from low-cost, corrosion-resistant, thermally stable metal films embedded in polymer structures. To date, however, there have been no demonstrations that combine all of these characteristics. We present here a method for patterning a film of aluminum on the photopolymer KMPR and treating the film to stabilize its resistivity. We demonstrate the production and stability of the films and demonstrate that they are suitable for use as heaters and/or temperature sensors at temperatures up to 165°C – well beyond the required temperatures for mainstay LOC functions such as the polymerase chain reaction (PCR).
Background
The aim was to review a consecutive series of patients treated with laparoscopic abdominal aortic aneurysm (AAA) repair. These patients were compared with patients having elective open AAA ...repair.
Methods
Demographic and operative details were collected prospectively and outcomes recorded for all patients undergoing laparoscopic or open AAA repair.
Results
A total of 316 patients underwent laparoscopic (51), open (53) or endovascular (EVAR; 212) AAA repair between 2007 and 2013. The median age of patients who had laparoscopic or open repair was 72 (i.q.r. 66–75) years, and 92·3 per cent were men. There was no significant difference in sex distribution, age or V‐POSSUM physiology score between laparoscopic and open repair. Of the 51 laparoscopic procedures, six were totally laparoscopic, 43 were laparoscopically assisted and two were converted to open repair. Pain scores were similar on days 1 and 3 after laparoscopic and open repair, even though epidurals were used in the open group, and were lower on days 5 and 7 after laparoscopic procedures. Patients who had laparoscopic repair had significantly fewer postoperative cardiorespiratory and renal complications (P = 0·017), and were discharged from hospital sooner (median 5 (i.q.r. 3–7) versus 8 (6–11) days; P = 0 ·001).
Conclusion
Laparoscopic AAA repair was performed safely, and with at least equivalent outcomes to open repair, in patients unfavourable for EVAR.
Equivalent to open
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