7 research outputs found
Lidar Measurements Supporting the Ocular Hazard Distance Calculation Using Atmospheric Attenuation
A series of lidar measurements has been performed at the Vidsel Test Range, Vidsel, situated in the inland of the very northern part of Sweden, as a part of an assessment of reducing the laser hazard distance using atmospheric attenuation within the calculations of nominal ocular hazard distance (NOHD). The question was “How low is the atmospheric attenuation as function of height in this area, using a wavelength of 1064 nm?” The work included building a ground based backscatter lidar, performing a series of measurements and analyzing the results. The measurements were performed during June to November, 2014, with the objective to measure at clear air and good weather situations.
The lidar measurements at 1064 nm showed a very low atmospheric attenuation as a function of height to altitudes of at least 10 km at several occasions. The lowest limit of backscatter coefficient possible to measure with this instrument is 0.3·10-7 m-1 sr-1. Assuming a lidar ratio varying between 30 – 100 sr, this was leading to an extinction coefficient of about 0.9 - 3·10-6 m-1. The atmospheric attenuation reduces the laser hazard distance with about 50 – 56 % depending on the lidar ratio. A recommendation is to monitor the atmospheric attenuation at the occasions when the method to the reduced laser hazard distance using atmospheric attenuation is used
Lidar Measurements Supporting the Ocular Hazard Distance Calculation Using Atmospheric Attenuation
A series of lidar measurements has been performed at the Vidsel Test Range, Vidsel, situated in the inland of the very northern part of Sweden, as a part of an assessment of reducing the laser hazard distance using atmospheric attenuation within the calculations of nominal ocular hazard distance (NOHD). The question was “How low is the atmospheric attenuation as function of height in this area, using a wavelength of 1064 nm?” The work included building a ground based backscatter lidar, performing a series of measurements and analyzing the results. The measurements were performed during June to November, 2014, with the objective to measure at clear air and good weather situations.
The lidar measurements at 1064 nm showed a very low atmospheric attenuation as a function of height to altitudes of at least 10 km at several occasions. The lowest limit of backscatter coefficient possible to measure with this instrument is 0.3·10-7 m-1 sr-1. Assuming a lidar ratio varying between 30 – 100 sr, this was leading to an extinction coefficient of about 0.9 - 3·10-6 m-1. The atmospheric attenuation reduces the laser hazard distance with about 50 – 56 % depending on the lidar ratio. A recommendation is to monitor the atmospheric attenuation at the occasions when the method to the reduced laser hazard distance using atmospheric attenuation is used
Lidar Measurements Supporting the Ocular Hazard Distance Calculation Using Atmospheric Attenuation
A series of lidar measurements has been performed at the Vidsel Test Range, Vidsel, situated in the inland of the very northern part of Sweden, as a part of an assessment of reducing the laser hazard distance using atmospheric attenuation within the calculations of nominal ocular hazard distance (NOHD). The question was “How low is the atmospheric attenuation as function of height in this area, using a wavelength of 1064 nm?” The work included building a ground based backscatter lidar, performing a series of measurements and analyzing the results. The measurements were performed during June to November, 2014, with the objective to measure at clear air and good weather situations.
The lidar measurements at 1064 nm showed a very low atmospheric attenuation as a function of height to altitudes of at least 10 km at several occasions. The lowest limit of backscatter coefficient possible to measure with this instrument is 0.3·10-7 m-1 sr-1. Assuming a lidar ratio varying between 30 – 100 sr, this was leading to an extinction coefficient of about 0.9 - 3·10-6 m-1. The atmospheric attenuation reduces the laser hazard distance with about 50 – 56 % depending on the lidar ratio. A recommendation is to monitor the atmospheric attenuation at the occasions when the method to the reduced laser hazard distance using atmospheric attenuation is used
Tryptic Peptide Reference Data Sets for MALDI Imaging Mass Spectrometry on Formalin-fixed Ovarian Cancer Tissues
MALDI imaging mass spectrometry is a powerful tool for
morphology-based
proteomic tissue analysis. However, peptide identification is still
a major challenge due to low S/N ratios, low mass accuracy and difficulties
in correlating observed <i>m</i>/<i>z</i> species
with peptide identities. To address this, we have analyzed tryptic
digests of formalin-fixed paraffin-embedded tissue microarray cores,
from 31 ovarian cancer patients, by LC–MS/MS. The sample preparation
closely resembled the MALDI imaging workflow in order to create representative
reference data sets containing peptides also observable in MALDI imaging
experiments. This resulted in 3844 distinct peptide sequences, at
a false discovery rate of 1%, for the entire cohort and an average
of 982 distinct peptide sequences per sample. From this, a total of
840 proteins and, on average, 297 proteins per sample could be inferred.
To support the efforts of the Chromosome-centric Human Proteome Project
Consortium, we have annotated these proteins with their respective
chromosome location. In the presented work, the benefit of using a
large cohort of data sets was exemplified by correct identification
of several <i>m</i>/<i>z</i> species observed
in a MALDI imaging experiment. The tryptic peptide data sets generated
will facilitate peptide identification in future MALDI imaging studies
on ovarian cancer
Tryptic Peptide Reference Data Sets for MALDI Imaging Mass Spectrometry on Formalin-fixed Ovarian Cancer Tissues
MALDI imaging mass spectrometry is a powerful tool for
morphology-based
proteomic tissue analysis. However, peptide identification is still
a major challenge due to low S/N ratios, low mass accuracy and difficulties
in correlating observed <i>m</i>/<i>z</i> species
with peptide identities. To address this, we have analyzed tryptic
digests of formalin-fixed paraffin-embedded tissue microarray cores,
from 31 ovarian cancer patients, by LC–MS/MS. The sample preparation
closely resembled the MALDI imaging workflow in order to create representative
reference data sets containing peptides also observable in MALDI imaging
experiments. This resulted in 3844 distinct peptide sequences, at
a false discovery rate of 1%, for the entire cohort and an average
of 982 distinct peptide sequences per sample. From this, a total of
840 proteins and, on average, 297 proteins per sample could be inferred.
To support the efforts of the Chromosome-centric Human Proteome Project
Consortium, we have annotated these proteins with their respective
chromosome location. In the presented work, the benefit of using a
large cohort of data sets was exemplified by correct identification
of several <i>m</i>/<i>z</i> species observed
in a MALDI imaging experiment. The tryptic peptide data sets generated
will facilitate peptide identification in future MALDI imaging studies
on ovarian cancer