Haemoglobin sensing with optical spectroscopy during minimally invasive procedures

Many clinical procedures involve the use of minimally invasive devices such as needles and catheters. Providing increased information about tissues that are adjacent to the device tips could reduce the probability of complications in these procedures. Optical fibres are well suited for integration into medical devices and they can be used to provide information relevant to tissue characterisation. This dissertation is centred on the integration of optical fibres into needles and catheters to obtain information about haemoglobin. In two studies, reflectance spectroscopy was performed. Two optical fibre geometries were tested, and for each, Monte Carlo simulations were used to estimate the reflectance values and the pho- ton penetration depths. In the first study, reflectance spectroscopy was performed with a double clad fibre. Experiments using expired human red blood cells were performed to determine the sensitivity of the measurements to oxygen saturation variation at physiological levels. Distinction between normal oxygen saturation values in veins and arteries was possible, making this fibre potentially useful to verify needle placement during a venous catheterisation or during a transseptal puncture. In the second study, two polymer optical light fibres were directly integrated into an epidural catheter. This optical catheter was tested during an ex-vivo swine laminectomy in the lumbar region. Another ex-vivo experiment was performed on chicken wings to discern blood vessels from other tissues. This information could be used during anaesthesic procedures to reduce the risk of toxicity from an intravascular injection. With reflectance spectroscopy, the depth in tissue from which signal is obtained is limited by the inter-fibre distance. This limitation motivated a third study, in which photoacoustic imaging was used to obtain image contrast for haemoglobin. The results of the three studies suggest that the integration of optical fibres into medical devices during minimally invasive procedures can allow for clinically relevant measurements of tissue properties in real-time

Application for RDP funds in terms of the “extension of municipal services presidential lead programme’’ as programme managed by the Department of Constitutional Affairs

The majority of the residents of Khutsong are employed at mines in the area south of Carletonville (stretching form East Driefontein in the east to Deelkraal in the west), as well as in Carletonville itself. The large majority of these people are dependant on public transport for commuting to work, for undertaking trips for shopping purposes and for going to school. The condition of the road network in Khutsong is of such a nature that large areas are totally inaccessible to public transport (especially in the rainy season) resulting in a situation where large numbers of people have to walk unacceptable long distances between their places of residence and public transport routes. A comprehensive programme have been embarked upon in consultation with the community to rectify this situation

Magnetorheological landing gear: 2. Validation using experimental data

Aircraft landing gears are subjected to a wide range of excitation conditions with conflicting damping requirements. A novel solution to this problem is to implement semi-active damping using magnetorheological (MR) fluids. In part 1 of this contribution, a methodology was developed that enables the geometry of a flow mode MR valve to be optimized within the constraints of an existing passive landing gear. The device was designed to be optimal in terms of its impact performance, which was demonstrated using numerical simulations of the complete landing gear system. To perform the simulations, assumptions were made regarding some of the parameters used in the MR shock strut model. In particular, the MR fluid's yield stress, viscosity, and bulk modulus properties were not known accurately. Therefore, the present contribution aims to validate these parameters experimentally, via the manufacture and testing of an MR shock strut. The gas exponent, which is used to model the shock strut's nonlinear stiffness, is also investigated. In general, it is shown that MR fluid property data at high shear rates are required in order to accurately predict performance prior to device manufacture. Furthermore, the study illustrates how fluid compressibility can have a significant influence on the device time constant, and hence on potential control strategies

AL-KABA’IR DALAM AL-QUR`AN (Studi Komparatif tafsir Ath-Thabari dan Tafsir Al-Kasysyaf)

Walaupun pentingnya menjauhi perbuatan dosa besar telah lumrah diketahui oleh setiap muslim, akan tetapi pengetian dari dosa besar itu sendiri dalam pandangan para ulama masih menuai banyak perbedaan. Sebagian menyatakan bahwa yang dinaksud dengan dosa besar adalah dosa yang mengakibatkan had (hukuman khusus) didunia dan diancam dengan (ancaman khusus) diakhirat, sementara yang lain menyatakan bahwa dosa besar adalah setiap dosa yang menimbulkan kerusakan yang besar. Penelitian ini menjadi menarik, sebab pandangan yang berbeda tersebut akan dilihat melalui lensa dua ahli tafsir yang menjadi acuan dari dua mazhab yang berbeda, yaitu Ath-Thabari dan AlZamakhsyari, dengan rumusan masalah: Bagaimana (1) pandangan dan penafsiran Ath-Thabari dan Al-Zamakhsyari prihal Al-Kaba’ir? Dan bagaimana (2) persamaan dan perbedaan kedua tokoh tersebut dalam menafsirkan AlKaba’ir? Penelitian ini berjenis library research dan menggunakan pendekatan: komparatif, Kemudian dianalisis secara deskriptif-analitis. Hasil penelitian menyebutkan bahwa (1) Ath-Thabari berpandangan bahwa yang dimaksud dengan Al-kaba’ir adalah: menyekutukan Allah SWT, durhaka kepada kedua orangtua, membunuh jiwa yang haram untuk dibunuh, berkata dengan perkataan dusta termasuk pula bersaksi dengan kesaksian palsu, menuduh wanita baik-baik berbuat zina, sihir, lari dari medan perang, dan berzina dengan istri tetangga. Sedangkan Al-Zamakhsyari berpandangan bahwa yang dimaksud dengan AlKaba’ir adalah: seluruh perbuatan dosa maksiat yang dilarang oleh Allah dan Rasul-Nya. Adapun argumentasi yang digunakan oleh Ath-Thabari: pertama, frase kabaa’iro maa tunhauna dalam Q.S An Nisa‟ ayat 31, adalah dosa-dosa besar khusus yang telah nabi kabarkan dalam hadis-hadis yang shohih. kedua, pandangan beliau bahwa tidak diperkenankan untuk melihat kategori dosa besar selain dari apa yang telah ada dalam hadis shohih. Sedangkan argumentasi yang digunakan oleh Al-Zamakhsyari: pertama, frase kabaa’iro maa tunhauna dalam Q.S An Nisa‟ ayat 31, adalah segala dosa-dosa yang dianggap besar. Kedua, pandangan beliau terhadap seluruh riwayat yang ada terkait dosa-dosa besar, seperti halnya perkataan Ibn Abbas ketika ditanya tentang dosa besar “Macamnya ada sampai tujuh puluh hingga tujuh ratus macam, yang paling ringkas adalah tujuh macam. Tetapi tidak ada dosa besar bila disertai dengan istigfar, dan tidak ada dosa kecil bila dibarengi dengan terus-menerus melakukannya”. (2)Ath-Thobari dan Al-zamakhsyari ketika menafsirkan ayatayat dosa besar mereka sama-sama menekankan tentang pentingnya menjauhi dosa besar dan menyatakan bahwa dosa besar hanya dapat terhapus dengan bertaubat, namun mereka berbeda dalam hal pengklafikasian dosa besar. Kata Kunci: Al-Kaba’ir,Al-Qur’an, Ath-Thabari, Al-Kasysya

Radiogenic backgrounds in the NEXT double beta decay experiment

Natural radioactivity represents one of the main backgrounds in the search for neutrinoless double beta decay. Within the NEXT physics program, the radioactivity- induced backgrounds are measured with the NEXT-White detector. Data from 37.9 days of low-background operations at the Laboratorio Subterráneo de Canfranc with xenon depleted in 136Xe are analyzed to derive a total background rate of (0.84±0.02) mHz above 1000 keV. The comparison of data samples with and without the use of the radon abatement system demonstrates that the contribution of airborne-Rn is negligible. A radiogenic background model is built upon the extensive radiopurity screening campaign conducted by the NEXT collaboration. A spectral fit to this model yields the specific contributions of 60Co, 40K, 214Bi and 208Tl to the total background rate, as well as their location in the detector volumes. The results are used to evaluate the impact of the radiogenic backgrounds in the double beta decay analyses, after the application of topological cuts that reduce the total rate to (0.25±0.01) mHz. Based on the best-fit background model, the NEXT-White median sensitivity to the two-neutrino double beta decay is found to be 3.5σ after 1 year of data taking. The background measurement in a Qββ±100 keV energy window validates the best-fit background model also for the neutrinoless double beta decay search with NEXT-100. Only one event is found, while the model expectation is (0.75±0.12) events. [Figure not available: see fulltext.]

Demonstration of the event identification capabilities of the NEXT-White detector

In experiments searching for neutrinoless double-beta decay, the possibility of identifying the two emitted electrons is a powerful tool in rejecting background events and therefore improving the overall sensitivity of the experiment. In this paper we present the first measurement of the efficiency of a cut based on the different event signatures of double and single electron tracks, using the data of the NEXT-White detector, the first detector of the NEXT experiment operating underground. Using a 228Th calibration source to produce signal-like and background-like events with energies near 1.6 MeV, a signal efficiency of 71.6 ± 1.5 stat± 0.3 sys% for a background acceptance of 20.6 ± 0.4 stat± 0.3 sys% is found, in good agreement with Monte Carlo simulations. An extrapolation to the energy region of the neutrinoless double beta decay by means of Monte Carlo simulations is also carried out, and the results obtained show an improvement in background rejection over those obtained at lower energies. [Figure not available: see fulltext.

Evaluating the current state of evolution acceptance instruments: a research coordination network meeting report

Hundreds of studies have explored student evolution acceptance because evolution is a core concept of biology that many undergraduate biology students struggle to accept. However, this construct of “evolution acceptance” has been defined and measured in various ways, which has led to inconsistencies across studies and difficulties in comparing results from different studies. Many studies and essays have offered evaluations and perspectives of evolution acceptance instruments, but publications with a focus on consensus building across research teams is still needed. Further, little attention has been paid to how evolution acceptance instruments may be interpreted differently by students with varied religious backgrounds. Funded by a Research Coordination Network in Undergraduate Biology Education grant from the National Science Foundation, we gathered 16 experts from different disciplinary and religious backgrounds to review current evolution acceptance instruments and create a guide to the strengths and weaknesses of these instruments, including appropriate contexts for using these instruments and their potential weaknesses with different religious populations. Finally, in an attempt to move the field forward, we articulated a consensus definition of evolution acceptance that can be used to guide future instrument development

The CYGNO experiment, a directional detector with optical readout for Dark Matter search

The CYGNO experiment employs a gaseous Time Projection Chamber (TPC) in conjunction with Gas Electron Multipliers (GEMs) for amplification and optical readout. This configuration holds the potential to achieve precise 3D tracking down to O(1 keV) energies. The primary objective of this novel technique is to enable direct directional measurements of Dark Matter within our Galaxy. We assess the performance of the largest prototype, LIME, at Laboratori Nazionali del Gran Sasso (LNGS), including stability, energy response and resolution, using radioactive X-ray sources and Monte Carlo simulations. These findings will guide the fine-tuning of the CYGNO 04 demonstrator

Electroluminescence TPCs at the thermal diffusion limit

[EN] The NEXT experiment aims at searching for the hypothetical neutrinoless double-beta decay from the 136Xe isotope using a high-purity xenon TPC. Efficient discrimination of the events through pattern recognition of the topology of primary ionisation tracks is a major requirement for the experiment. However, it is limited by the diffusion of electrons. It is known that the addition of a small fraction of a molecular gas to xenon reduces electron diffusion. On the other hand, the electroluminescence (EL) yield drops and the achievable energy resolution may be compromised. We have studied the effect of adding several molecular gases to xenon (CO2, CH4 and CF4) on the EL yield and energy resolution obtained in a small prototype of driftless gas proportional scintillation counter. We have compared our results on the scintillation characteristics (EL yield and energy resolution) with a microscopic simulation, obtaining the diffusion coefficients in those conditions as well. Accordingly, electron diffusion may be reduced from about 10 mm/ sqrt(¿) for pure xenon down to 2.5 mm/sqrt(m) using additive concentrations of about 0.05%, 0.2% and 0.02% for CO2, CH4 and CF4, respectively. Our results show that CF4 admixtures present the highest EL yield in those conditions, but very poor energy resolution as a result of huge fluctuations observed in the EL formation. CH4 presents the best energy resolution despite the EL yield being the lowest. The results obtained with xenon admixtures are extrapolated to the operational conditions of the NEXT-100 TPC. CO2 and CH4 show potential as molecular additives in a large xenon TPC. While CO2 has some operational constraints, making it difficult to be used in a large TPC, CH4 shows the best performance and stability as molecular additive to be used in the NEXT-100 TPC, with an extrapolated energy resolution of 0.4% at 2.45 MeV for concentrations below 0.4%, which is only slightly worse than the one obtained for pure xenon. We demonstrate the possibility to have an electroluminescence TPC operating very close to the thermal diffusion limit without jeopardizing the TPC performance, if CO2 or CH4 are chosen as additives.The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economia y Competitividad of Spain under grants FIS2014-53371-C04, the Severo Ochoa Program SEV-2014-0398 and the Maria de Maetzu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014, under project UID/FIS/04559/2013 to fund the activities of LIBPhys, and under grants PD/BD/105921/2014, SFRH/BPD/109180/2015 and SFRH/BPD/76842/2011; the U.S. Department of Energy under contracts number DE-AC02-07CH11359 (Fermi National Accelerator Laboratory), DE-AC02-06CH11357 (Argonne National Laboratory), DE-FG02-13ER42020 (Texas A&M) and DE-SC0017721 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015-18820. We also warmly acknowledge the Laboratori Nazionali del Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.Henriques, CAO.; Monteiro, CMB.; Gonzalez-Diaz, D.; Azevedo, CDR.; Freitas, EDC.; Mano, RDP.; Jorge, MR.... (2019). Electroluminescence TPCs at the thermal diffusion limit. Journal of High Energy Physics (Online). 1:1-20. https://doi.org/10.1007/JHEP01(2019)027S1201NEXT collaboration, J. Martín-Albo et al., Sensitivity of NEXT-100 to neutrinoless double beta decay, JHEP 05 (2016) 159 [ arXiv:1511.09246 ] [ INSPIRE ].T. Brunner et al., An RF-only ion-funnel for extraction from high-pressure gases, Intern. J. Mass Spectrom. 379 (2015) 110 [ INSPIRE ].PANDAX-III collaboration, J. Galan, Microbulk MicrOMEGAs for the search of 0νββ of 136 Xe in the PandaX-III experiment, 2016 JINST 11 P04024 [ arXiv:1512.09034 ] [ INSPIRE ].D. Yu. Akimov, A.A. Burenkov, V.F. Kuzichev, V.L. Morgunov and V.N. Solovev, Low background experiments with high pressure gas scintillation proportional detector, physics/9704021 [ INSPIRE ].Yu. M. Gavrilyuk et al., A technique for searching for the 2K capture in 124 Xe with a copper proportional counter, Phys. Atom. Nucl. 78 (2015) 1563 [ INSPIRE ].D.R. Nygren, Columnar recombination: a tool for nuclear recoil directional sensitivity in a xenon-based direct detection WIMP search, J. Phys. Conf. Ser. 460 (2013) 012006 [ INSPIRE ].XENON collaboration, E. Aprile et al., First Dark Matter Search Results from the XENON1T Experiment, Phys. Rev. Lett. 119 (2017) 181301 [ arXiv:1705.06655 ] [ INSPIRE ].XENON100 collaboration, E. Aprile et al., Dark Matter Results from 225 Live Days of XENON100 Data, Phys. Rev. Lett. 109 (2012) 181301 [ arXiv:1207.5988 ] [ INSPIRE ].LUX collaboration, D.S. Akerib et al., Results from a search for dark matter in the complete LUX exposure, Phys. Rev. Lett. 118 (2017) 021303 [ arXiv:1608.07648 ] [ INSPIRE ].PandaX-II collaboration, X. Cui et al., Dark Matter Results From 54-Ton-Day Exposure of PandaX-II Experiment, Phys. Rev. Lett. 119 (2017) 181302 [ arXiv:1708.06917 ] [ INSPIRE ].EXO collaboration, J.B. Albert et al., Search for Neutrinoless Double-Beta Decay with the Upgraded EXO-200 Detector, Phys. Rev. Lett. 120 (2018) 072701 [ arXiv:1707.08707 ] [ INSPIRE ].KamLAND-Zen collaboration, A. Gando et al., Search for Majorana Neutrinos near the Inverted Mass Hierarchy Region with KamLAND-Zen, Phys. Rev. Lett. 117 (2016) 082503 [ arXiv:1605.02889 ] [ INSPIRE ].XMASS collaboration, K. Abe et al., Search for two-neutrino double electron capture on 124 Xe with the XMASS-I detector, Phys. Lett. B 759 (2016) 64 [ arXiv:1510.00754 ] [ INSPIRE ].XENON collaboration, E. Aprile et al., Search for two-neutrino double electron capture of 124 Xe with XENON100, Phys. Rev. C 95 (2017) 024605 [ arXiv:1609.03354 ] [ INSPIRE ].R. Lüscher et al., Search for ββ decay in 136 Xe: new results from the Gotthard experiment, Phys. Lett. B 434 (1998) 407 [ INSPIRE ].NEXT collaboration, P. Ferrario et al., First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment, JHEP 01 (2016) 104 [ arXiv:1507.05902 ] [ INSPIRE ].NEXT collaboration, D. Lorca et al., Characterisation of NEXT-DEMO using xenon K α X-rays, 2014 JINST 9 P10007 [ arXiv:1407.3966 ] [ INSPIRE ].NEXT collaboration, D. González-Díaz et al., Accurate γ and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm, Nucl. Instrum. Meth. A 804 (2015) 8 [ arXiv:1504.03678 ] [ INSPIRE ].C.M.B. Monteiro et al., Secondary Scintillation Yield in Pure Xenon, 2007 JINST 2 P05001 [ physics/0702142 ] [ INSPIRE ].C.M.B. Monteiro, J.A.M. Lopes, J.F. C.A. Veloso and J.M.F. dos Santos, Secondary scintillation yield in pure argon, Phys. Lett. B 668 (2008) 167 [ INSPIRE ].E.D.C. Freitas et al., Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0νββ) search, Phys. Lett. B 684 (2010) 205 [ INSPIRE ].C.M.B. Monteiro et al., Secondary scintillation yield from gaseous micropattern electron multipliers in direct dark matter detection, Phys. Lett. B 677 (2009) 133 [ INSPIRE ].C.M.B. Monteiro, L.M.P. Fernandes, J.F. C.A. Veloso, C.A.B. Oliveira and J.M.F. dos Santos, Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search, Phys. Lett. B 714 (2012) 18 [ INSPIRE ].C. Balan et al., MicrOMEGAs operation in high pressure xenon: Charge and scintillation readout, 2011 JINST 6 P02006 [ arXiv:1009.2960 ] [ INSPIRE ].J.M.F. dos Santos et al., Development of portable gas proportional scintillation counters for x-ray spectrometry, X-Ray Spectrom. 30 (2001) 373.NEXT collaboration, J. Renner et al., Background rejection in NEXT using deep neural networks, 2017 JINST 12 T01004 [ arXiv:1609.06202 ] [ INSPIRE ].T. Himi et al., Emission spectra from Ar-Xe, Ar-Kr, Ar-N2, Ar-CH4, Ar-CO2 and Xe-N2 gas proportional scintillation counters, Nucl. Instrum. Meth. 205 (1983) 591.C.D.R. Azevedo et al., An homeopathic cure to pure Xenon large diffusion, 2016 JINST 11 C02007 [ arXiv:1511.07189 ] [ INSPIRE ].NEXT collaboration, C.A.O. Henriques et al., Secondary scintillation yield of xenon with sub-percent levels of CO 2 additive for rare-event detection, Phys. Lett. B 773 (2017) 663 [ arXiv:1704.01623 ] [ INSPIRE ].P.C.P.S. Simões, J.M.F. dos Santos and C.A.N. Conde, Driftless gas proportional scintillation counter pulse analysis using digital processing techniques, X Ray Spectrom. 30 (2001) 342.P.C.P.S. Simões et al., A new method for pulse analysis of driftless-gas proportional scintillation counters, Nucl. Instrum. Meth. A 505 (2003) 247.C.D.R. Azevedo et al., Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives, Nucl. Instrum. Meth. A 877 (2018) 157 [ arXiv:1705.09481 ] [ INSPIRE ].L.M.P. Fernandes et al., Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter, 2010 JINST 5 P09006 [Erratum ibid. 5 (2010) A12001] [ arXiv:1009.2719 ] [ INSPIRE ].C.M.B. Monteiro et al., An argon gas proportional scintillation counter with UV avalanche photodiode scintillation readout, IEEE Trans. Nucl. Sci. 48 (2001) 1081.J.A.M. Lopes et al., A xenon gas proportional scintillation counter with a UV-sensitive large-area avalanche photodiode, IEEE Trans. Nucl. Sci. 48 (2001) 312.D.F. Anderson et al., A large area gas scintillation proportional counter, Nucl. Instrum. Meth. 163 (1979) 125.Z. Kowalski et al., Fano factor implications from gas scintillation proportional counter measurements, Nucl. Instrum. Meth. A 279 (1989) 567.S.J.C. do Carmo et al., Experimental study of the ω-values and Fano factors of gaseous xenon and Ar-Xe mixtures for X-rays, IEEE Trans. Nucl. Sci. 55 (2008) 2637.http://magboltz.web.cern.ch/magboltz/ (accessed 14.11.2016).T.H.V.T. Dias et al., Full-energy absorption of x-ray energies near the Xe L- and K-photoionization thresholds in xenon gas detectors: Simulation and experimental results, J. Appl. Phys. 82 (1997) 2742.D. Nygren, High-pressure xenon gas electroluminescent TPC for 0νββ-decay search, Nucl. Instrum. Meth. A 603 (2009) 337 [ INSPIRE ].NEXT collaboration, V. Álvarez et al., The NEXT-100 experiment for neutrinoless double beta decay searches (Conceptual Design Report), arXiv:1106.3630 [ INSPIRE ].NEXT collaboration, V. Álvarez et al., Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array, 2013 JINST 8 P09011 [ arXiv:1306.0471 ] [ INSPIRE ]

Demonstration of background rejection using deep convolutional neural networks in the NEXT experiment

Convolutional neural networks (CNNs) are widely used state-of-the-art computer vision tools that are becoming increasingly popular in high-energy physics. In this paper, we attempt to understand the potential of CNNs for event classification in the NEXT experiment, which will search for neutrinoless double-beta decay in 136Xe. To do so, we demonstrate the usage of CNNs for the identification of electron-positron pair production events, which exhibit a topology similar to that of a neutrinoless double-beta decay event. These events were produced in the NEXT-White high-pressure xenon TPC using 2.6 MeV gamma rays from a 228Th calibration source. We train a network on Monte Carlo-simulated events and show that, by applying on-the-fly data augmentation, the network can be made robust against differences between simulation and data. The use of CNNs offers significant improvement in signal efficiency and background rejection when compared to previous non-CNN-based analyses. [Figure not available: see fulltext.