The Experts below are selected from a list of 210 Experts worldwide ranked by ideXlab platform
C J Hirschmugl - One of the best experts on this subject based on the ideXlab platform.
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correction cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:Correction for ‘Cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows’ by Ebrahim Aboualizadeh et al., Analyst, 2015, 140, 4046–4056.
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cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:The chemical status of live sensory neurons is accessible with Infrared microspectroscopy of appropriately prepared cells. In this paper, individual dorsal root ganglion (DRG) neurons have been prepared with two different protocols, and plated on glass cover slips, BaF2 and CaF2 substrates. The first protocol exposes the intact DRGs to 4 °C for between 20–30 minutes before dissociating individual neurons and plating 2 hours later. The second protocol maintains the neurons at 23 °C for the entire duration of the sample preparation. The visual appearance of the neurons is similar. The viability was assessed by means of trypan blue exclusion method to determine the viability of the neurons. The neurons prepared under the first protocol (cold exposure) and plated on BaF2 reveal a distinct chemical signature and chemical distribution that is different from the other sample preparations described in the paper. Importantly, results for other sample preparation methods, using various substrates and temperature protocols, when compared across the overlapping spectral bandwidth, present normal chemical distribution within the neurons. The unusual chemically specific spatial variation is dominated by a lack of protein and carbohydrates in the center of the neurons and signatures of unraveling DNA are detected. We suggest that cold shock leads to apoptosis of DRGs, followed by osmotic stress originating from ion gradients across the cell membrane leading to cell lysis.
Keith P Shine - One of the best experts on this subject based on the ideXlab platform.
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atmospheric observations of the water vapour continuum in the near Infrared Windows between 2500 and 6600 cm 1
Atmospheric Measurement Techniques, 2020Co-Authors: Jonathan Elsey, Marc D Coleman, T Gardiner, Kaah P Menang, Keith P ShineAbstract:Abstract. Water vapour continuum absorption is potentially important for both closure of the Earth's energy budget and remote sensing applications. Currently, there are significant uncertainties in its characteristics in the near-Infrared atmospheric Windows at 2.1 and 1.6 µ m. There have been several attempts to measure the continuum in the laboratory; not only are there significant differences amongst these measurements, but there are also difficulties in extrapolating the laboratory data taken at room temperature and above to temperatures more widely relevant to the atmosphere. Validation is therefore required using field observations of the real atmosphere. There are currently no published observations in atmospheric conditions with enough water vapour to detect a continuum signal within these Windows or where the self-continuum component is significant. We present observations of the near-Infrared water vapour continuum from Camborne, UK, at sea level using a Sun-pointing, radiometrically calibrated Fourier transform spectrometer in the window regions between 2000 and 10 000 cm −1 . Analysis of these data is challenging, particularly because of the need to remove aerosol extinction and the large uncertainties associated with such field measurements. Nevertheless, we present data that are consistent with recent laboratory datasets in the 4 and 2.1 µ m Windows (when extrapolated to atmospheric temperatures). These results indicate that the most recent revision (3.2) of the MT_CKD foreign continuum, versions of which are widely used in atmospheric radiation models, requires strengthening by a factor of ∼5 in the centre of the 2.1 µ m window. In the higher-wavenumber window at 1.6 µ m, our estimated self- and foreign-continua are significantly stronger than MT_CKD. The possible contribution of the self- and foreign-continua to our derived total continuum optical depth is estimated by using laboratory or MT_CKD values of one, to estimate the other. The obtained self-continuum shows some consistency with temperature-extrapolated laboratory data in the centres of the 4 and 2.1 µ m Windows. The 1.6 µ m region is more sensitive to atmospheric aerosol and continuum retrievals and therefore more uncertain than the more robust results at 2.1 and 4 µ m. We highlight the difficulties in observing the atmospheric continuum and make the case for additional measurements in both the laboratory and field and discuss the requirements for any future field campaign.
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the water vapour continuum in near Infrared Windows current understanding and prospects for its inclusion in spectroscopic databases
Journal of Molecular Spectroscopy, 2016Co-Authors: Keith P Shine, I V Ptashnik, Robert Mcpheat, A Campargue, D Mondelain, Damien WeidmannAbstract:Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, Infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth’s atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-Infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-Infrared window regions (centred on 4700 and 6300 cm−1) and include reference to the window centred on 2600 cm−1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback – cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring Windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these Windows. In individual Windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-Infrared Windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum – as an example, we report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.
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The water vapour continuum in near-Infrared Windows – Current understanding and prospects for its inclusion in spectroscopic databases
Journal of Molecular Spectroscopy, 2016Co-Authors: Keith P Shine, I V Ptashnik, Robert Mcpheat, A Campargue, D Mondelain, Damien WeidmannAbstract:Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, Infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth’s atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-Infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-Infrared window regions (centred on 4700 and 6300 cm−1) and include reference to the window centred on 2600 cm−1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback – cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring Windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these Windows. In individual Windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-Infrared Windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum – as an example, we report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.
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water vapour foreign continuum absorption in near Infrared Windows from laboratory measurements
Philosophical Transactions of the Royal Society A, 2012Co-Authors: I V Ptashnik, Robert Mcpheat, Keith P Shine, K M Smith, Gary R WilliamsAbstract:For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high Infrared transmittance (so-called ‘Windows’) was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H2O−H2O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H2O−N2 bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the Windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430 K in four near-Infrared Windows between 1.1 and 5 μm (9000–2000 cm−1). Our results indicate that the foreign continuum in these Windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated Windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46 W m−2 (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer–Tobin–Clough–Kneizys–Davies) foreign-continuum model.
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water vapor self continuum absorption in near Infrared Windows derived from laboratory measurements
Journal of Geophysical Research, 2011Co-Authors: I V Ptashnik, Robert Mcpheat, Keith P Shine, K M Smith, Gary R WilliamsAbstract:In most near-Infrared atmospheric Windows, absorption of solar radiation is dominated by the water vapor self-continuum and yet there is a paucity of measurements in these Windows. We report new laboratory measurements of the self-continuum absorption at temperatures between 293 and 472 K and pressures from 0.015 to 5 atm in four near-Infrared Windows between 1 and 4 m (10000-2500 cm-1); the measurements are made over a wider range of wavenumber, temperatures and pressures than any previous measurements. They show that the self-continuum in these Windows is typically one order of magnitude stronger than given in representations of the continuum widely used in climate and weather prediction models. These results are also not consistent with current theories attributing the self continuum within Windows to the far-wings of strong spectral lines in the nearby water vapor absorption bands; we suggest that they are more consistent with water dimers being the major contributor to the continuum. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by 0.75 W/m2 (which is about 1% of the total clear-sky absorption) by using these new measurements as compared to calculations with the MT_CKD-2.5 self-continuum model.
Ebrahim Aboualizadeh - One of the best experts on this subject based on the ideXlab platform.
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correction cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:Correction for ‘Cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows’ by Ebrahim Aboualizadeh et al., Analyst, 2015, 140, 4046–4056.
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cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:The chemical status of live sensory neurons is accessible with Infrared microspectroscopy of appropriately prepared cells. In this paper, individual dorsal root ganglion (DRG) neurons have been prepared with two different protocols, and plated on glass cover slips, BaF2 and CaF2 substrates. The first protocol exposes the intact DRGs to 4 °C for between 20–30 minutes before dissociating individual neurons and plating 2 hours later. The second protocol maintains the neurons at 23 °C for the entire duration of the sample preparation. The visual appearance of the neurons is similar. The viability was assessed by means of trypan blue exclusion method to determine the viability of the neurons. The neurons prepared under the first protocol (cold exposure) and plated on BaF2 reveal a distinct chemical signature and chemical distribution that is different from the other sample preparations described in the paper. Importantly, results for other sample preparation methods, using various substrates and temperature protocols, when compared across the overlapping spectral bandwidth, present normal chemical distribution within the neurons. The unusual chemically specific spatial variation is dominated by a lack of protein and carbohydrates in the center of the neurons and signatures of unraveling DNA are detected. We suggest that cold shock leads to apoptosis of DRGs, followed by osmotic stress originating from ion gradients across the cell membrane leading to cell lysis.
I V Ptashnik - One of the best experts on this subject based on the ideXlab platform.
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the water vapour continuum in near Infrared Windows current understanding and prospects for its inclusion in spectroscopic databases
Journal of Molecular Spectroscopy, 2016Co-Authors: Keith P Shine, I V Ptashnik, Robert Mcpheat, A Campargue, D Mondelain, Damien WeidmannAbstract:Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, Infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth’s atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-Infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-Infrared window regions (centred on 4700 and 6300 cm−1) and include reference to the window centred on 2600 cm−1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback – cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring Windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these Windows. In individual Windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-Infrared Windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum – as an example, we report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.
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The water vapour continuum in near-Infrared Windows – Current understanding and prospects for its inclusion in spectroscopic databases
Journal of Molecular Spectroscopy, 2016Co-Authors: Keith P Shine, I V Ptashnik, Robert Mcpheat, A Campargue, D Mondelain, Damien WeidmannAbstract:Spectroscopic catalogues, such as GEISA and HITRAN, do not yet include information on the water vapour continuum that pervades visible, Infrared and microwave spectral regions. This is partly because, in some spectral regions, there are rather few laboratory measurements in conditions close to those in the Earth’s atmosphere; hence understanding of the characteristics of the continuum absorption is still emerging. This is particularly so in the near-Infrared and visible, where there has been renewed interest and activity in recent years. In this paper we present a critical review focusing on recent laboratory measurements in two near-Infrared window regions (centred on 4700 and 6300 cm−1) and include reference to the window centred on 2600 cm−1 where more measurements have been reported. The rather few available measurements, have used Fourier transform spectroscopy (FTS), cavity ring down spectroscopy, optical-feedback – cavity enhanced laser spectroscopy and, in very narrow regions, calorimetric interferometry. These systems have different advantages and disadvantages. Fourier Transform Spectroscopy can measure the continuum across both these and neighbouring Windows; by contrast, the cavity laser techniques are limited to fewer wavenumbers, but have a much higher inherent sensitivity. The available results present a diverse view of the characteristics of continuum absorption, with differences in continuum strength exceeding a factor of 10 in the cores of these Windows. In individual Windows, the temperature dependence of the water vapour self-continuum differs significantly in the few sets of measurements that allow an analysis. The available data also indicate that the temperature dependence differs significantly between different near-Infrared Windows. These pioneering measurements provide an impetus for further measurements. Improvements and/or extensions in existing techniques would aid progress to a full characterisation of the continuum – as an example, we report pilot measurements of the water vapour self-continuum using a supercontinuum laser source coupled to an FTS. Such improvements, as well as additional measurements and analyses in other laboratories, would enable the inclusion of the water vapour continuum in future spectroscopic databases, and therefore allow for a more reliable forward modelling of the radiative properties of the atmosphere. It would also allow a more confident assessment of different theoretical descriptions of the underlying cause or causes of continuum absorption.
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water vapour foreign continuum absorption in near Infrared Windows from laboratory measurements
Philosophical Transactions of the Royal Society A, 2012Co-Authors: I V Ptashnik, Robert Mcpheat, Keith P Shine, K M Smith, Gary R WilliamsAbstract:For a long time, it has been believed that atmospheric absorption of radiation within wavelength regions of relatively high Infrared transmittance (so-called ‘Windows’) was dominated by the water vapour self-continuum, that is, spectrally smooth absorption caused by H2O−H2O pair interaction. Absorption due to the foreign continuum (i.e. caused mostly by H2O−N2 bimolecular absorption in the Earth's atmosphere) was considered to be negligible in the Windows. We report new retrievals of the water vapour foreign continuum from high-resolution laboratory measurements at temperatures between 350 and 430 K in four near-Infrared Windows between 1.1 and 5 μm (9000–2000 cm−1). Our results indicate that the foreign continuum in these Windows has a very weak temperature dependence and is typically between one and two orders of magnitude stronger than that given in representations of the continuum currently used in many climate and weather prediction models. This indicates that absorption owing to the foreign continuum may be comparable to the self-continuum under atmospheric conditions in the investigated Windows. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by approximately 0.46 W m−2 (or 0.6% of the total clear-sky absorption) by using these new measurements when compared with calculations applying the widely used MTCKD (Mlawer–Tobin–Clough–Kneizys–Davies) foreign-continuum model.
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water vapor self continuum absorption in near Infrared Windows derived from laboratory measurements
Journal of Geophysical Research, 2011Co-Authors: I V Ptashnik, Robert Mcpheat, Keith P Shine, K M Smith, Gary R WilliamsAbstract:In most near-Infrared atmospheric Windows, absorption of solar radiation is dominated by the water vapor self-continuum and yet there is a paucity of measurements in these Windows. We report new laboratory measurements of the self-continuum absorption at temperatures between 293 and 472 K and pressures from 0.015 to 5 atm in four near-Infrared Windows between 1 and 4 m (10000-2500 cm-1); the measurements are made over a wider range of wavenumber, temperatures and pressures than any previous measurements. They show that the self-continuum in these Windows is typically one order of magnitude stronger than given in representations of the continuum widely used in climate and weather prediction models. These results are also not consistent with current theories attributing the self continuum within Windows to the far-wings of strong spectral lines in the nearby water vapor absorption bands; we suggest that they are more consistent with water dimers being the major contributor to the continuum. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by 0.75 W/m2 (which is about 1% of the total clear-sky absorption) by using these new measurements as compared to calculations with the MT_CKD-2.5 self-continuum model.
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Water vapor self‐continuum absorption in near‐Infrared Windows derived from laboratory measurements
Journal of Geophysical Research, 2011Co-Authors: I V Ptashnik, Robert Mcpheat, Keith P Shine, K M Smith, R. Gary WilliamsAbstract:In most near-Infrared atmospheric Windows, absorption of solar radiation is dominated by the water vapor self-continuum and yet there is a paucity of measurements in these Windows. We report new laboratory measurements of the self-continuum absorption at temperatures between 293 and 472 K and pressures from 0.015 to 5 atm in four near-Infrared Windows between 1 and 4 m (10000-2500 cm-1); the measurements are made over a wider range of wavenumber, temperatures and pressures than any previous measurements. They show that the self-continuum in these Windows is typically one order of magnitude stronger than given in representations of the continuum widely used in climate and weather prediction models. These results are also not consistent with current theories attributing the self continuum within Windows to the far-wings of strong spectral lines in the nearby water vapor absorption bands; we suggest that they are more consistent with water dimers being the major contributor to the continuum. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by 0.75 W/m2 (which is about 1% of the total clear-sky absorption) by using these new measurements as compared to calculations with the MT_CKD-2.5 self-continuum model.
Cheryl L Stucky - One of the best experts on this subject based on the ideXlab platform.
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correction cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:Correction for ‘Cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows’ by Ebrahim Aboualizadeh et al., Analyst, 2015, 140, 4046–4056.
-
cold shock induces apoptosis of dorsal root ganglion neurons plated on Infrared Windows
Analyst, 2015Co-Authors: Ebrahim Aboualizadeh, Eric C Mattson, Crystal L Ohara, Amanda K Smith, Cheryl L Stucky, C J HirschmuglAbstract:The chemical status of live sensory neurons is accessible with Infrared microspectroscopy of appropriately prepared cells. In this paper, individual dorsal root ganglion (DRG) neurons have been prepared with two different protocols, and plated on glass cover slips, BaF2 and CaF2 substrates. The first protocol exposes the intact DRGs to 4 °C for between 20–30 minutes before dissociating individual neurons and plating 2 hours later. The second protocol maintains the neurons at 23 °C for the entire duration of the sample preparation. The visual appearance of the neurons is similar. The viability was assessed by means of trypan blue exclusion method to determine the viability of the neurons. The neurons prepared under the first protocol (cold exposure) and plated on BaF2 reveal a distinct chemical signature and chemical distribution that is different from the other sample preparations described in the paper. Importantly, results for other sample preparation methods, using various substrates and temperature protocols, when compared across the overlapping spectral bandwidth, present normal chemical distribution within the neurons. The unusual chemically specific spatial variation is dominated by a lack of protein and carbohydrates in the center of the neurons and signatures of unraveling DNA are detected. We suggest that cold shock leads to apoptosis of DRGs, followed by osmotic stress originating from ion gradients across the cell membrane leading to cell lysis.