119 research outputs found
Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978–1987
Digital Elevation Models (DEMs) play a prominent role in glaciological studies for the mass balance of glaciers and ice sheets. By providing a time snapshot of glacier geometry, DEMs are crucial for most glacier evolution modelling studies, but are also important for cryospheric modelling in general. We present a historical medium-resolution DEM and orthophotographs that consistently cover the entire surroundings and margins of the Greenland Ice Sheet 1978–1987. About 3,500 aerial photographs of Greenland are combined with field surveyed geodetic ground control to produce a 25 m gridded DEM and a 2 m black-and-white digital orthophotograph. Supporting data consist of a reliability mask and a photo footprint coverage with recording dates. Through one internal and two external validation tests, this DEM shows an accuracy better than 10 m horizontally and 6 m vertically while the precision is better than 4 m. This dataset proved successful for topographical mapping and geodetic mass balance. Other uses include control and calibration of remotely sensed data such as imagery or InSAR velocity maps
Accuracy of optical spectroscopy for the detection of cervical intraepithelial neoplasia without colposcopic tissue information; a step toward automation for low resource settings
Optical spectroscopy has been proposed as an accurate and low-cost alternative for detection of cervical
intraepithelial neoplasia. We previously published an algorithm using optical spectroscopy as an adjunct to colposcopy
and found good accuracy (sensitivity ¼ 1.00 [95% confidence interval ðCIÞ ¼ 0.92 to 1.00], specificity ¼
0.71 [95% CI ¼ 0.62 to 0.79]). Those results used measurements taken by expert colposcopists as well as the colposcopy
diagnosis. In this study, we trained and tested an algorithm for the detection of cervical intraepithelial
neoplasia (i.e., identifying those patients who had histology reading CIN 2 or worse) that did not include the colposcopic
diagnosis. Furthermore, we explored the interaction between spectroscopy and colposcopy, examining
the importance of probe placement expertise. The colposcopic diagnosis-independent spectroscopy algorithm
had a sensitivity of 0.98 (95% CI ¼ 0.89 to 1.00) and a specificity of 0.62 (95% CI ¼ 0.52 to 0.71). The difference
in the partial area under the ROC curves between spectroscopy with and without the colposcopic diagnosis was
statistically significant at the patient level (p ¼ 0.05) but not the site level (p ¼ 0.13). The results suggest that the
device has high accuracy over a wide range of provider accuracy and hence could plausibly be implemented by
providers with limited training
Human Parainfluenza Virus Type 1 C Proteins Are Nonessential Proteins That Inhibit the Host Interferon and Apoptotic Responses and Are Required for Efficient Replication in Nonhuman Primates
Recombinant human parainfluenza virus type 1 (rHPIV1) was modified to create rHPIV1-P(C−), a virus in which expression of the C proteins (C′, C, Y1, and Y2) was silenced without affecting the amino acid sequence of the P protein. Infectious rHPIV1-P(C−) was readily recovered from cDNA, indicating that the four C proteins were not essential for virus replication. Early during infection in vitro, rHPIV1-P(C−) replicated as efficiently as wild-type (wt) HPIV1, but its titer subsequently decreased coincident with the onset of an extensive cytopathic effect not observed with wt rHPIV1. rHPIV1-P(C−) infection, but not wt rHPIV1 infection, induced caspase 3 activation and nuclear fragmentation in LLC-MK2 cells, identifying the HPIV1 C proteins as inhibitors of apoptosis. In contrast to wt rHPIV1, rHPIV1-P(C−) and rHPIV1-CF170S, a mutant encoding an F170S substitution in C, induced interferon (IFN) and did not inhibit IFN signaling in vitro. However, only rHPIV1-P(C−) induced apoptosis. Thus, the anti-IFN and antiapoptosis activities of HPIV1 were separable: both activities are disabled in rHPIV1-P(C−), whereas only the anti-IFN activity is disabled in rHPIV1-CF170S. In African green monkeys (AGMs), rHPIV1-P(C−) was considerably more attenuated than rHPIV1-CF170S, suggesting that disabling the anti-IFN and antiapoptotic activities of HPIV1 had additive effects on attenuation in vivo. Although rHPIV1-P(C−) protected against challenge with wt HPIV1, its highly restricted replication in AGMs and in primary human airway epithelial cell cultures suggests that it might be overattenuated for use as a vaccine. Thus, the C proteins of HPIV1 are nonessential but have anti-IFN and antiapoptosis activities required for virulence in primates
First -decay spectroscopy of and new -decay branches of
19 pags., 14 figs., 3 tabs.The decay of the neutron-rich and was investigated experimentally in order to provide new insights into the nuclear structure of the tin isotopes with magic proton number above the shell. The -delayed -ray spectroscopy measurement was performed at the ISOLDE facility at CERN, where indium isotopes were selectively laser-ionized and on-line mass separated. Three -decay branches of were established, two of which were observed for the first time. Population of neutron-unbound states decaying via rays was identified in the two daughter nuclei of and , at excitation energies exceeding the neutron separation energy by 1 MeV. The -delayed one- and two-neutron emission branching ratios of were determined and compared with theoretical calculations. The -delayed one-neutron decay was observed to be dominant -decay branch of even though the Gamow-Teller resonance is located substantially above the two-neutron separation energy of . Transitions following the decay of are reported for the first time, including rays tentatively attributed to . In total, six new levels were identified in on the basis of the coincidences observed in the and decays. A transition that might be a candidate for deexciting the missing neutron single-particle state in was observed in both decays and its assignment is discussed. Experimental level schemes of and are compared with shell-model predictions. Using the fast timing technique, half-lives of the , and levels in were determined. From the lifetime of the state measured for the first time, an unexpectedly large transition strength was deduced, which is not reproduced by the shell-model calculations.M.P.-S. acknowledges the funding support from the Polish National Science Center under Grants No.
2019/33/N/ST2/03023 and No. 2020/36/T/ST2/00547 (Doctoral scholarship ETIUDA). J.B. acknowledges
support from the Universidad Complutense de Madrid under the Predoctoral Grant No. CT27/16-
CT28/16. This work was partially funded by the Polish National Science Center under Grants No.
2020/39/B/ST2/02346, No. 2015/18/E/ST2/00217, and No. 2015/18/M/ST2/00523, by the Spanish
government via Projects No. FPA2017-87568-P, No. RTI2018-098868-B-I00, No. PID2019-104390GB-I00,
and No. PID2019-104714GB-C21, by the U.K. Science and Technology Facilities Council (STFC), the German BMBF
under Contract No. 05P18PKCIA, by the Portuguese FCT under the Projects No. CERN/FIS-PAR/0005/2017, and
No. CERN/FIS-TEC/0003/2019, and by the Romanian IFA Grant CERN/ISOLDE. The research leading to these
results has received funding from the European Union’s Horizon 2020 research and innovation programme under
Grant Agreement No. 654002. M.Str. acknowledges the funding from the European Union’s Horizon 2020 research
and innovation program under Grant Agreement No. 771036 (ERC CoG MAIDEN). J.P. acknowledges support from the
Academy of Finland (Finland) with Grant No. 307685. Work at the University of York was supported under STFC Grants
No. ST/L005727/1 and No. ST/P003885/1
First beta-decay spectroscopy of In-135 and new beta-decay branches of In-134
The beta decay of the neutron-rich In-134 and In-135 was investigated experimentally in order to provide new insights into the nuclear structure of the tin isotopes with magic proton number Z = 50 above the N = 82 shell. The beta-delayed gamma-ray spectroscopy measurement was performed at the ISOLDE facility at CERN, where indium isotopes were selectively laser-ionized and on-line mass separated. Three beta-decay branches of In-134 were established, two of which were observed for the first time. Population of neutron-unbound states decaying via. rays was identified in the two daughter nuclei of In-134, Sn-134 and Sn-133, at excitation energies exceeding the neutron separation energy by 1 MeV. The beta-delayed one- and two-neutron emission branching ratios of In-134 were determined and compared with theoretical calculations. The beta-delayed one-neutron decay was observed to be dominant beta-decay branch of In-134 even though the Gamow-Teller resonance is located substantially above the two-neutron separation energy of Sn-134. Transitions following the beta decay of In-135 are reported for the first time, including. rays tentatively attributed to Sn-135. In total, six new levels were identified in Sn-134 on the basis of the beta.. coincidences observed in the In-134 and In-135 beta decays. A transition that might be a candidate for deexciting the missing neutron single-particle 13/2(+) state in Sn-133 was observed in both beta decays and its assignment is discussed. Experimental level schemes of Sn-134 and Sn-135 are compared with shell-model predictions. Using the fast timing technique, half-lives of the 2(+), 4(+), and 6(+) levels in Sn-134 were determined. From the lifetime of the 4(+) state measured for the first time, an unexpectedly large B(E2; 4(+)-> 2(+)) transition strength was deduced, which is not reproduced by the shell-model calculations.Peer reviewe
New ß-decaying state in 214Bi
A new β-decaying state in 214Bi has been identified at the ISOLDE Decay Station at the CERN-ISOLDE facility. A preferred Iπ = (8−) assignment was suggested for this state based on the β-decay feeding pattern to levels in 214Po and shell-model calculations. The half-life of the Iπ = (8−) state was deduced to be T1/2 = 9.39(10) min. The deexcitation of the levels populated in 214Po by the β decay of this state was investigated via γ -γ coincidences and a number of new levels and transitions was identified. Shell-model calculations for excited states in 214Bi and 214Po were performed using two different effective interactions: the H208 and the modified Kuo-Herling particle interaction. Both calculations agree on the interpretation of the new β-decaying state as an Iπ = 8− isomer and allow for tentative assignment of shell-model states to several high-spin states in 214Po.peerReviewe
New ß-decaying state in 214Bi
A new β-decaying state in 214Bi has been identified at the ISOLDE Decay Station at the CERN-ISOLDE facility. A preferred Iπ = (8−) assignment was suggested for this state based on the β-decay feeding pattern to levels in 214Po and shell-model calculations. The half-life of the Iπ = (8−) state was deduced to be T1/2 = 9.39(10) min. The deexcitation of the levels populated in 214Po by the β decay of this state was investigated via γ -γ coincidences and a number of new levels and transitions was identified. Shell-model calculations for excited states in 214Bi and 214Po were performed using two different effective interactions: the H208 and the modified Kuo-Herling particle interaction. Both calculations agree on the interpretation of the new β-decaying state as an Iπ = 8− isomer and allow for tentative assignment of shell-model states to several high-spin states in 214Po.peerReviewe
Radiocarbon chronology of glacial lake sediments in the Retezat Mts (South Carpathians, Romania): a window to Late Glacial and Holocene climatic and paleoenvironmental changes
- …