Revisiting the link between business strategy and performance: Evidence from hotels

This paper aims to investigate the competitive success factors for hotel companies and examine the link between business strategy and performance. Using a structured questionnaire, the researchers collected data from hotel managers in Spain. Study results suggest that a firm’s assets and strategies have a greater influence on performance than industry forces do. This lack of direct influence by industry forces is due to the sector’s specific characteristics, which cannot be overlooked during analysis. Based on these research findings, theoretical and managerial implications and future research are presented

Performance of the most recent Microchannel-Plate PMTs for the PANDA DIRC detectors at FAIR

In the PANDA experiment at the FAIR facility at GSI two DIRC (Detection of Internally Reflected Cherenkov light) detectors will be used for $\pi$/K separation up to 4 GeV/c. Due to their location in a high magnetic field and other stringent requirements like high detection efficiency, low dark count rate, radiation hardness, long lifetime and good timing, MCP-PMTs (microchannel-plate photomultiplier) were the best choice of photon sensors for the DIRC detectors in the PANDA experiment. This paper will present the performance of some of the latest 2$\times$2 inch$^2$ MCP-PMTs from Photek and Photonis, including the first mass production tubes for the PANDA Barrel DIRC from Photonis. Performance parameters like the collection efficiency (CE), quantum efficiency (QE), and gain homogeneity were determined. The effect of magnetic fields on some properties like gain and charge cloud width was investigated as well. Apart from that the spatial distribution of many internal parameters like time resolution, dark count rate, afterpulse ratio, charge sharing crosstalk and recoil electrons were measured simultaneously with a multihit capable DAQ system. The latest generation of Photonis MCP-PMTs shows an unexpected "escalation" effect where the MCP-PMT itself produces photons.Comment: Proceedings contribution to RICH2022 (11th International Workshop on Ring Imaging Cherenkov Detectors

Lifetime and performance of the very latest microchannel-plate photomultipliers

The PANDA experiment at the FAIR facility at GSI will study hadron physics using a high intensity antiproton beam of up to 15 GeV/c momentum to perform high precision spectroscopy. Two DIRC detectors with their image planes residing in an $\sim$1 T magnetic field will be used in the experiment. The only suitable photon detectors for both DIRCs were identified to be Microchannel-Plate Photomultipliers (MCP-PMTs). Since the aging problems of MCP-PMTs were solved recently by coating the MCPs with the so-called ALD-technique (atomic layer deposition) we are investigating devices which are significantly improved with respect to other parameters, as, e.g., the collection efficiency (CE) and the quantum efficiency (QE). The latest generation of MCP-PMTs can reach a detective quantum efficiency DQE = QE - CE of 30%. This paper will present the performance of the most advanced 53 $\times$ 53 mm$^2$ ALD-coated MCP-PMTs from Photonis (8 $\times$ 8 and 3 $\times$ 100 anodes) and Photek (8 $\times$ 8 anodes), also inside the magnetic field. With a picosecond laser and a multi-hit capable DAQ system which allows read out up to 300 pixels simultaneously, parameters like darkcount rate, afterpulse probability and time resolution can be investigated as a function of incident photon position.Comment: Proceedings contribution to NDIP20 (9th Conference on New Developments in Photodetection

Increased homocysteine levels impair reference memory and reducecortical levels of acetylcholine in a mouse model of vascular cognitive impairment

Folates are B-vitamins that are vital for normal brain function. Deficiencies in folates either genetic(methylenetetrahydrofolate reductase, MTHFR) or dietary intake of folic acid result in elevated levelsof homocysteine. Clinical studies have shown that elevated levels of homocysteine (Hcy) may be associ-ated with the development of dementia, however this link remains unclear. The purpose of this study wasto evaluate the impact of increased Hcy levels on a mouse model of vascular cognitive impairment (VCI)produced by chronic hypoperfusion. Male and female Mthfr+/+and Mthfr+/−mice were placed on eithercontrol (CD) or folic acid deficient (FADD) diets after which all animals underwent microcoil implantationaround each common carotid artery or a sham procedure. Post-operatively animals were tested on theMorris water maze (MWM), y-maze, and rotarod. Animals had no motor impairments on the rotarod,y-maze, and could learn the location of the platform on the MWM. However, on day 8 of testing of MWMtesting during the probe trial, Mthfr+/−FADD microcoil mice spent significantly less time in the targetquadrant when compared to Mthfr+/−CD sham mice, suggesting impaired reference memory. All FADDmice had elevated levels of plasma homocysteine. MRI analysis revealed arterial remodeling was present in Mthfr+/− microcoil mice not Mthfr+/+ mice. Acetylcholine and related metabolites were reduced in cortical tissue because of microcoil implantation and elevated levels of homocysteine. Deficiencies in folate metabolism resulting in increased Hcy levels yield a metabolic profile that increases susceptibility to neurodegeneration in a mouse model of VCI

International links between Streptococcus pneumoniae vaccine serotype 4 sequence type (ST) 801 in Northern European shipyard outbreaks of invasive pneumococcal disease

Background: Pneumococcal disease outbreaks of vaccine preventable serotype 4 sequence type (ST)801 in shipyards have been reported in several countries. We aimed to use genomics to establish any international links between them. Methods: Sequence data from ST801-related outbreak isolates from Norway (n = 17), Finland (n = 11) and Northern Ireland (n = 2) were combined with invasive pneumococcal disease surveillance from the respective countries, and ST801-related genomes from an international collection (n = 41 of > 40,000), totalling 106 genomes. Raw data were mapped and recombination excluded before phylogenetic dating. Results: Outbreak isolates were relatively diverse, with up to 100 SNPs (single nucleotide polymorphisms) and a common ancestor estimated around the year 2000. However, 19 Norwegian and Finnish isolates were nearly indistinguishable (0–2 SNPs) with the common ancestor dated around 2017. Conclusion: The total diversity of ST801 within the outbreaks could not be explained by recent transmission alone, suggesting that harsh environmental and associated living conditions reported in the shipyards may facilitate invasion of colonising pneumococci. However, near identical strains in the Norwegian and Finnish outbreaks does suggest that transmission between international shipyards also contributed to those outbreaks. This indicates the need for improved preventative measures in this working population including pneumococcal vaccination

Search for pair production of excited top quarks in the lepton plus jets final state

A search is performed for the pair production of spin-3/2 excited top quarks, each decaying to a top quark and a gluon. The search uses the data collected with the CMS detector from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). Events are selected by requiring an isolated muon or electron, an imbalance in the transverse momentum, and at least six jets of which exactly two must be compatible with originating from the fragmentation of a bottom quark. No significant excess over the standard model predictions is found. A lower limit of 1.2 TeV is set at 95% confidence level on the mass of the spin-3/2 excited top quark in an extension of the Randall-Sundrum model, assuming a 100% branching fraction of its decay into a top quark and a gluon. These are the best limits to date in a search for excited top quarks and the first at 13 TeV. (c) 2018 The Author(s). Published by Elsevier B. V.Peer reviewe

Azimuthal correlations for inclusive 2-jet, 3-jet, and 4-jet events in pp collisions at root s=13 TeV

Azimuthal correlations between the two jets with the largest transverse momenta p(T) in inclusive 2-, 3-, and 4-jet events are presented for several regions of the leading jet p(T) up to 4 TeV. For 3- and 4-jet scenarios, measurements of the minimum azimuthal angles between any two of the three or four leading p(T) jets are also presented. The analysis is based on data from proton-proton collisions collected by the CMS Collaboration at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1). Calculations based on leading-order matrix elements supplemented with parton showering and hadronization do not fully describe the data, so next-to-leading-order calculations matched with parton shower and hadronization models are needed to better describe the measured distributions. Furthermore, we show that azimuthal jet correlations are sensitive to details of the parton showering, hadronization, and multiparton interactions. Anext-to-leading-order calculation matched with parton showers in the MC@NLO method, as implemented in HERWIG 7, gives a better overall description of the measurements than the powheg method.Peer reviewe

Search for top squarks and dark matter particles in opposite-charge dilepton final states at root s=13 TeV

A search for new physics is presented in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from b quarks, and missing transverse momentum (p(T)(miss)). The search uses proton-proton collision data at root s = 13 TeV amounting to 35.9 fb(-1) of integrated luminosity collected using the CMS detector in 2016. Hypothetical signal events are efficiently separated from the dominant t (t) over bar background with requirements on p(T)(miss) and transverse-mass variables. No significant deviation is observed from the expected background. Exclusion limits are set in the context of simplified supersymmetric models with pair-produced top squarks. For top squarks, decaying exclusively to a top quark and a neutralino, exclusion limits are placed at 95% confidence level on the mass of the lightest top squark up to 800 GeVand on the lightest neutralino up to 360 GeV. These results, combined with searches in the single-lepton and all-jet final states, raise the exclusion limits up to 1050 GeV for the lightest top squark and up to 500 GeV for the lightest neutralino. For top squarks undergoing a cascade decay through charginos and sleptons, the mass limits reach up to 1300 GeV for top squarks and up to 800 GeV for the lightest neutralino. The results are also interpreted in a simplified model with a dark matter (DM) particle coupled to the top quark through a scalar or pseudoscalar mediator. For light DM, mediator masses up to 100 (50) GeV are excluded for scalar (pseudoscalar) mediators. The result for the scalar mediator achieves some of the most stringent limits to date in this model.Peer reviewe