Using 3 Dimension Health Vegetation Index Point Clouds to Determine HLB Infected Citrus Trees

Three-dimensional NDVI point clouds can be an innovative method for detecting Huanglongbing (HLB) disease in citrus trees. In February 2018, an Unmanned Aircraft System (UAS) captured narrow-band multispectral images to detect healthiness variations of infected citrus trees. A 30-acre section of a citrus grove in Florida with a known HLB infection was examined to determine if three-dimensional Normalized Difference Vegetation Index (NDVI) point clouds can indicate healthiness variations in HLB-infected citrus trees and how three-dimensional NDVI point clouds compared to two-dimensional NDVI reflectance maps for detecting healthiness variations in HLB-infected citrus trees. Wilcoxon Sign Rank testing compared Whole-Tree Vegetation Indices (WTVI) comprising of point or pixel proportions within five NDVI classifications between three-dimensional NVDI point clouds and two-dimensional NDVI reflectance maps. The results indicated significant differences between three-dimensional and two-dimensional points, grouped at the tree level, for suspected HLB-infected trees (p = 0.000). The data suggests three-dimensional NDVI point cloud points were more sensitive to less healthy levels of NDVI values by 2.7% compared to two dimensional NDVI data for suspected HLB-infected trees and by 10.6% (p = 0.000) for non-suspected HLB-infected trees. Researchers concluded three-dimensional NDVI point clouds could be used to determine healthiness variations in suspected HLB-infected citrus trees. Three-dimensional NVDI point clouds had a wider distribution of five index classifications than two-dimensional NDVI reflectance maps for suspected HLB-infected trees. The vertical structure of the citrus tree may contribute to the difference in distribution. There was a 10.01% (p = 0.021) increase in 3D NDVI point cloud points for non-suspected HLB-infected trees compared to the suspected HLB-infected trees. Additionally, there was a 9.04% (p = 0.032) increase in tree crown dimension for non-suspected HLB-infected trees compared to suspected HLB-infected trees. These data suggest non-suspected HLB-infected trees were larger than suspected HLB-infected trees

Magnetic Survey at the Roman Military Camp of el Benian in Mauretania Tingitana (Morocco): Results and Implications

The topic of military settlements and the role of troops in the northern provinces of North Africa during the age of the Roman Empire has recently gained a strong interest in historical, archaeological, epigraphical, and economic studies. In particular, at Mauretania Tingitana (in the north-east area of modern-day Morocco), the presence of numerous military camps in the Early and Later Roman Empire has now been assessed. In this framework, the present work deals with the geophysical survey, by means of magnetometry, at the site of el Benian, where the largest military camp is located. In particular, the magnetic survey has highlighted the organization of the camp, almost totally unknown previously. The result of the magnetic survey has confirmed intense building activity over the centuries and made it possible to identify and characterize the structures typical of a military field

Moving Target Analysis in ISAR Image Sequences with a Multiframe Marked Point Process Model

In this paper we propose a Multiframe Marked Point Process model of line segments and point groups for automatic target structure extraction and tracking in Inverse Synthetic Aperture Radar (ISAR) image sequences. For the purpose of dealing with scatterer scintillations and high speckle noise in the ISAR frames, we obtain the resulting target sequence by an iterative optimization process, which simultaneously considers the observed image data and various prior geometric interaction constraints between the target appearances in the consecutive frames. A detailed quantitative evaluation is performed on 8 real ISAR image sequences of different carrier ship and airplane targets, using a test database containing 545 manually annotated frames

50 años de investigación en ciencias económicas

El Instituto de Investigaciones Económicas de la UNAM (IIEC), fundado en 1940, cumple sus primeros cincuenta años. En ocasión del cincuentenario, además de rescatar algunos datos históricos, hemos considerado pertinente incluir algunas reflexiones acerca de las perspectivas de desarrollo de la ciencia económica ante los desafíos que nos plantea la realidad contemporánea. Con este propósito, este artículo reproduce algunas de las ideas más sobresalientes expresadas por el Lic. Benito Rey y por el Mtro. José Luis Ceceña, Director e Investigador Emérito del IIEC, respectivamente, en el acto de homenaje que tuvo lugar el 8 de noviembre de 1990

The Power of Water: A Study on the Integration of Geothermal and Glacial Resources in Iceland

Iceland\u27s unique geographic location provides the people with one main source of energy to keep them powered: water. Iceland can harness the energy from both geothermal and glacial water sources providing a sustainable lifestyle influenced further by the country’s culture. The water sources also provide a stable industry and economy for the population. Although easily accessible and plentiful, the water-based energy sources are carefully planned and constructed to prevent negative environmental impacts. Through a qualitative approach, research was conducted through field observations in country, interviews with natives, and through secondary accounts. These key water sources in Iceland essentially power the whole island. Future studies can be conducted as to the continued impact of these water sources, outside of Iceland. Future topics can include Iceland’s energy grid contributing to the number of outside investors and joint ventures occurring in country, further environmental effects of harvesting hydropower, and a projected study on how the nation would survive without using hydropower

The Power of Water: A Study on the Integration of Geothermal and Glacial Resources in Iceland

This study discusses the uses of Iceland’s geothermal and glacial water resources and their impacts. Iceland’s exceptional geographical location provides residents with their main source of energy: water. The water resources provide for a unique lifestyle that directly influence Iceland’s residents and tourists. Harvesting the natural energy takes careful planning for the integration of technology to prevent significant, negative environmental impacts. These natural water resources has places an emphasis on sustainable living

Hatching phenology and voltinism of Heterocypris barbara (Crustacea: Ostracoda) from Lampedusa (Sicily, Italy)

The persistence of crustacean populations in ephemeral ponds requires appropriate adaptations in life history strategies (e.g. in hatching phenology). Organisms take advantage of pond filling when it occurs and hedge their bets for the possibility to complete one or more life cycles or to produce resting stages that ensure that the population will not go extinct. We carried out laboratory experiments to investigate the dynamics of a sexual population of Heterocypris barbara from a vernal pool in Lampedusa Island (Sicily). Experimental organisms were obtained hydrating sediments from Aria Rossa temporary pond. Recruitment from resting eggs, voltinism, mean body size and sex ratio were observed in microcosms at different conductivities (high 2.0-2.7 mS cm-1, intermediate 1.0-1.1 mS cm-1 and low 0.5-0.6 mS cm-1). Microcosms were kept in laboratory controlled conditions: constant (24°C 12:12 L:D and 16°C 10:14 L:D photoperiod) or fluctuating thermal regimes. The experiment lasted 7 months. Resting and non-resting egg production and up to a bivoltine life cycle were observed. Recruitment events from egg bank and voltinism varied by thermal regime and conductivity. A prolonged recruitment phase occurred in conditions that could be considered a proxy of a rainy season (16°C, 10:14 L:D and low conductivity) or of long hydroperiods (spring thermal fluctuating regime and intermediate conductivity). At 24°C, age at reproduction of females from resting eggs almost doubled at low conductivity (in comparison with high conductivity). Low conductivity also reduced hatching time of resting eggs while it increased development time and age at maturity. In thermal fluctuating regime, degree-days to reproduction were about double than at constant 24°C. Males, observed in all microcosms, reached maturity faster and had a shorter life span than females. Males initially outnumbered females, but later in the experiments females became dominant. We also evaluated the effect of conductivity and thermal regimes on other traits like recruitment from egg bank, voltinism and sex ratio. We discuss whether our observations on a small population from temporary pools could be considered part of a diversified bet-hedging strategy

Use of Genetic Algorithms for Contrast and Entropy Optimization in ISAR Autofocusing

Image contrast maximization and entropy minimization are two commonly used techniques for ISAR image autofocusing. When the signal phase history due to the target radial motion has to be approximated with high order polynomial models, classic optimization techniques fail when attempting to either maximize the image contrast or minimize the image entropy. In this paper a solution of this problem is proposed by using genetic algorithms. The performances of the new algorithms that make use of genetic algorithms overcome the problem with previous implementations based on deterministic approaches. Tests on real data of airplanes and ships confirm the insight