294,130 research outputs found
Use of new generation geospatial data and technology for low cost drought monitoring and SDG reporting solution : a thesis presented in partial fulfillment of the requirement for the degree of Master of Science in Computer Science at Massey University, Manawatū, New Zealand
Food security is dependent on ecosystems including forests, lakes and wetlands,
which in turn depend on water availability and quality. The importance of water
availability and monitoring drought has been highlighted in the Sustainable Development
Goals (SDGs) within the 2030 agenda under indicator 15.3. In this context
the UN member countries, which agreed to the SDGs, have an obligation to report
their information to the UN. The objective of this research is to develop a methodology
to monitor drought and help countries to report their ndings to UN in a
cost-e ective manner.
The Standard Precipitation Index (SPI) is a drought indicator which requires longterm
precipitation data collected from weather stations as per World Meteorological
Organization recommendation. However, weather stations cannot monitor large areas
and many developing countries currently struggling with drought do not have
access to a large number of weather-stations due to lack of funds and expertise.
Therefore, alternative methodologies should be adopted to monitor SPI.
In this research SPI values were calculated from available weather stations in Iran
and New Zealand. By using Google Earth Engine (GEE), Sentinel-1 and Sentinel-
2 imagery and other complementary data to estimate SPI values. Two genetic
algorithms were created, one which constructed additional features using indices
calculated from Sentinel-2 imagery and the other data which was used for feature
selection of the Sentinel-2 indices including the constructed features. Followed by
the feature selection process two datasets were created which contained the Sentinel-
1 and Sentinel-2 data and other complementary information such as seasonal data
and Shuttle Radar Topography Mission (SRTM) derived information.
The Automated Machine Learning tool known as TPOT was used to create optimized
machine learning pipelines using genetic programming. The resulting models yielded an average of 90 percent accuracy in 10-fold cross validation for the Sentinel-
1 dataset and an average of approximately 70 percent for the Sentinel-2 dataset. The
nal model achieved a test accuracy of 80 percent in classifying short-term SPI (SPI-
1 and SPI-3) and an accuracy of 65 percent of SPI-6 by using the Sentinel-1 test
dataset. However, the results generated by using Sentinel-2 dataset was lower than
Sentinel-1 (45 percent for SPI-1 and 65 percent for SPI-6) with the exception of
SPI-3 which had an accuracy of 85 percent.
The research shows that it is possible to monitor short-term SPI adequately using
cost free satellite imagery in particular Sentinel-1 imagery and machine learning. In
addition, this methodology reduces the workload on statistical o ces of countries
in reporting information to the SDG framework for SDG indicator 15.3. It emerged
that Sentinel-1 imagery alone cannot be used to monitor SPI and therefore complementary
data are required for the monitoring process.
In addition the use of Sentinel-2 imagery did not result in accurate results for SPI-1
and SPI-6 but adequate results for SPI-3. Further research is required to investigate
how the use of Sentinel-2 imagery with Sentinel-1 imagery impact the accuracy of
the models
A modified sentinel node and occult lesion localization (SNOLL) technique in non-palpable breast cancer. A pilot study
Background: The spread of mammographic screening programs has allowed an increasing amount of early breast
cancer diagnosis. A modern approach to non-palpable breast lesions requires an accurate intraoperative localization, in
order to achieve a complete surgical resection. In addiction, the assessment of lymph node status is mandatory as it
represents a major prognostic factor in these patients. The aim of this study is to evaluate the reliability of a modified
technical approach using a single nanocolloidal radiotracer to localize both sentinel node and breast occult lesion.
Methods: Twenty-five patients with a single non-palpable breast lesions and clinically negative axilla were enrolled. In the
same day of surgery, patients underwent intratumoral and peritumoral administration of 99mTc-labeled nanocolloid tracer
under sonographic guidance. A lymphoscintigraphy was performed to localize the sentinel lymph node and its cutaneous
projection was marked on the skin in order to guide the surgeon to an optimal incision. During surgery an hand-held
gamma-detection probe was used to select the best surgical access route and to guide localization of both occult breast
lesion and sentinel lymph node. After specimen excision, the surgical field was checked with the gamma-probe to verify
the absence of residual sources of significant radioactivity, thereby ensuring a radical treatment in a single surgical session
and minimizing normal tissue excision.
Results: Both targeted breast lesion and sentinel lymph node were localized and removed at the first attempt in every
patients and histopathological diagnosis of malignancy was confirmed in 25/26 samples. Non-palpable lesions were
included within the surgical margins in all patients and in all samples surgical margins were free from neoplastic infiltration
thus avoiding any further reintervention. Only two patients showed metastatic involvement of sentinel lymph node.
Conclusions: The modified sentinel node and occult lesion localization (SNOLL) technique performed with a single
injection of nanocolloidal radiotracer has shown an excellent intraoperative identification rate of both non-palpable lesion
and sentinel lymph node. This procedure offers, as opposed to standard techniques, an accurate, simple and reliable
approach to the management of non-palpable breast cancer
Super-resolving multiresolution images with band-independant geometry of multispectral pixels
A new resolution enhancement method is presented for multispectral and
multi-resolution images, such as these provided by the Sentinel-2 satellites.
Starting from the highest resolution bands, band-dependent information
(reflectance) is separated from information that is common to all bands
(geometry of scene elements). This model is then applied to unmix
low-resolution bands, preserving their reflectance, while propagating
band-independent information to preserve the sub-pixel details. A reference
implementation is provided, with an application example for super-resolving
Sentinel-2 data.Comment: Source code with a ready-to-use script for super-resolving Sentinel-2
data is available at http://nicolas.brodu.net/recherche/superres
Evaluation of Landsat-8 and Sentinel-2A Aerosol Optical Depth Retrievals Across Chinese Cities and Implications for Medium Spatial Resolution Urban Aerosol Monitoring
In urban environments, aerosol distributions may change rapidly due to building and transport infrastructure and human population density variations. The recent availability of medium resolution Landsat-8 and Sentinel-2 satellite data provide the opportunity for aerosol optical depth (AOD) estimation at higher spatial resolution than provided by other satellites. AOD retrieved from 30 m Landsat-8 and 10 m Sentinel-2A data using the Land Surface Reflectance Code (LaSRC) were compared with coincident ground-based Aerosol Robotic Network (AERONET) Version 3 AOD data for 20 Chinese cities in 2016. Stringent selection criteria were used to select contemporaneous data; only satellite and AERONET data acquired within 10 min were considered. The average satellite retrieved AOD over a 1470 m1470 m window centered on each AERONET site was derived to capture fine scale urban AOD variations. AERONET Level 1.5 (cloud-screened) and Level 2.0 (cloud-screened and also quality assured) data were considered. For the 20 urban AERONET sites in 2016 there were 106 (Level 1.5) and 67 (Level 2.0) Landsat-8 AERONET AOD contemporaneous data pairs, and 118 (Level 1.5) and 89 (Level 2.0) Sentinel-2A AOD data pairs. The greatest AOD values (>1.5) occurred in Beijing, suggesting that the Chinese capital was one of the most polluted cities in China in 2016. The LaSRC Landsat-8 and Sentinel-2A AOD retrievals agreed well with the AERONET AOD data (linear regression slopes > 0.96; coefficient of determination r(exp 2) > 0.90; root mean square deviation < 0.175) and demonstrate that the LaSRC is an effective and applicable medium resolution AOD retrieval algorithm over urban environments. The Sentinel-2A AOD retrievals had better accuracy than the Landsat-8 AOD retrievals, which is consistent with previously published research.The implications of the research and the potential for urban aerosol monitoring by combining the freely available Landsat-8 and Sentinel-2 satellite data are discussed
Shattered by War: The Huber Family
The tale of Sergent Frederick Huber is relatively well known. The young man, fighting at the battle of Fair Oaks, was struck by three rounds, the final a bullet through his breast that quickly sapped him of his life. The Adams Sentinel reported the incident in the early summer days of 1862, underlining Frederick\u27s bravery in the face of the great beyond. Tell Father, he reportedly said with his dying breath, according to the Sentinel, I have died for my country. [excerpt
Carbon dioxide baited trap catches do not correlate with human landing collections of Anopheles aquasalis in Suriname
Three types of carbon dioxide-baited traps, i.e., the Centers for Disease Control Miniature Light Trap without light, the BioGents (BG) Sentinel Mosquito Trap (BG-Sentinel) and the Mosquito Magnet® Liberty Plus were compared with human landing collections in their efficiency in collecting Anopheles (Nyssorhynchus) aquasalis mosquitoes. Of 13,549 total mosquitoes collected, 1,019 (7.52%) were An. aquasalis. Large numbers of Culex spp were also collected, in particular with the (BG-Sentinel). The majority of An. aquasalis (83.8%) were collected by the human landing collection (HLC). None of the trap catches correlated with HLC in the number of An. aquasalis captured over time. The high efficiency of the HLC method indicates that this malaria vector was anthropophilic at this site, especially as carbon dioxide was insufficiently attractive as stand-alone bait. Traps using carbon dioxide in combination with human odorants may provide better results
Effectiveness of entomopathogenic nematodes in the control of Cydia pomonella larvae in Northern Italy
Since 2006, a large scale research on the effectiveness of entomopathogenic nematodes
(EPN) in the control of codling moth (CM), Cydia pomonella, overwintering larvae has
been performed on about 35 ha of pear orchards per year in Emilia-Romagna, Northern
Italy. Steinernema carpocapsae and Steinernema feltiae activity was checked after spray
applications of EPNs to the trunk and branches. In 2006, the treatment was applied either
in spring or in autumn at different doses, before CM pupation; in 2007 the EPN treatment
was applied only in autumn at 1.5 x 109 I.J. ha –1. Every year it was distributed by means of
a conventional mist blower. The larval mortality was assessed directly on sentinel larvae in
card boards on the trunks and indirectly on the eggs laid by the females of the first CM
generation in spring. Moreover, each year, a trial was performed applying only S.
carpocapsae on sentinel larvae with the aim of testing this nematode at suitable
temperatures but at different water volumes.
The CM sentinel larvae were effectively parasitized after autumnal EPN application.
Moreover, the egg assessment demonstrated a good decrease in CM population in spring
2007, when EPNs had been applied at the best weather conditions (t° 12-14 °C and rain)
in the previous autumn
Current status of sentinel lymph node biopsy in solid malignancies
Lymphatic mapping and sentinel lymph node biopsy were first reported in 1977 by Cabanas for penile cancer. Since that time, the technique has become rapidly assimilated into clinical practice. The sentinel node concept has been validated in cutaneous melanoma and breast cancer. However, follow-up data of patients from randomised trials is needed to establish the clinical significance of sentinel lymph node biopsy before accepting the procedure as a standard of care. This technique has the potential to be utilised in all solid tumours like colon, gastric, oesophageal, lung, gynaecologic, and head and neck cancer. This paper reviews the current status of sentinel lymph node biopsy in solid tumours
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