33 research outputs found
Focusing and amplification of electromagnetic waves by time reversal in an leaky reverberation chamber
Agricultural Education in Today’s School System: An Evaluation of Agricultural and Related Science Courses among High Schools in Alabama, USA
Previous studies on global food security have indicated that in order to sustain the global population by the year 2050, a significant increase in food production will be needed. Consequently, it is crucial that today’s students are educated to realize this increasing food demand. One of the problems is that currently too few students seem to be interested in pursuing studies in the fields of agriculture and related sciences. By exploring three research questions, this study assesses the extent to which high school students in each of the 67 counties in the U.S. state of Alabama are being exposed to agricultural-related science courses. For the purposes of this assessment, the high schools were grouped by zones—Northern, Central, Southern and the Black Belt. Relevant high school data, including courses offered, were compiled from Alabama’s Department of Education 2017 directory. Microsoft Excel and SPSS software were used to analyze the data. The findings of this study demonstrated that there are spatial differences in agriculture-related courses offered in high schools in Alabama’s Northern, Central and Southern regions. Future research should further investigate what percentage of high school students actually choose agriculture or related disciplines as their professional career paths after graduating from high school
Agricultural Education in Today’s School System: An Evaluation of Agricultural and Related Science Courses among High Schools in Alabama, USA
Previous studies on global food security have indicated that in order to sustain the global population by the year 2050, a significant increase in food production will be needed. Consequently, it is crucial that today’s students are educated to realize this increasing food demand. One of the problems is that currently too few students seem to be interested in pursuing studies in the fields of agriculture and related sciences. By exploring three research questions, this study assesses the extent to which high school students in each of the 67 counties in the U.S. state of Alabama are being exposed to agricultural-related science courses. For the purposes of this assessment, the high schools were grouped by zones—Northern, Central, Southern and the Black Belt. Relevant high school data, including courses offered, were compiled from Alabama’s Department of Education 2017 directory. Microsoft Excel and SPSS software were used to analyze the data. The findings of this study demonstrated that there are spatial differences in agriculture-related courses offered in high schools in Alabama’s Northern, Central and Southern regions. Future research should further investigate what percentage of high school students actually choose agriculture or related disciplines as their professional career paths after graduating from high school
Recensions: René Luneau ; Deux colloques sur Marie Guyard de l\u27Incarnation ; Charlotte de Castelnau-l\u27Estoile ; lan Breward ; Marc Ferro.
Biophotonic in situ sensor for plant leaves
International audienceKnowledge of the water concentration of plants can be helpful in several environmental and agricultural domains. There are many methods for the determination of water content in plant leaves; however, most of them give a relative moisture level or an analytical measure after a previous calibration procedure. Even for other biochemical compounds such as dry matter or chlorophyll, the measurement techniques could be destructive. For this reason, a nondestructive method has been developed to measure the biochemical compounds of a plant leaf, using an infrared spectroscopy technique. One important advantage is the simplicity of the device (RAdiometre portatif de Mesure In Situ, RAMIS) and its capability to perform measurements in situ. The prototype is a leaf-clip configuration and is made of LEDs at five wavelengths (656, 721, 843, 937, and 1550 nm), and a silicon/germanium photosensor. To compute the water content of vegetative leaves, the radiative transfer model PROSPECT was implemented. This model can accurately predict spectral transmittances in the 400 nm to 2500 nm spectral region as a function of the principal leaf biochemical contents: water, dry matter, and chlorophyll. Using the transmittance measured by RAMIS into an inversion procedure of PROSPECT: A Model of Leaf Optical Properties Spectra, we are able to compute the values of water contents that show an agreement with the water contents measured directly using dry weight procedures. This method is presented as a possibility to estimate other leaf biochemical compounds using appropriate wavelengths. (C) 2010 Optical Society of Americ
Neural network implementation for a reversal procedure for water and dry matter estimation on plant leaves using selected LED wavelengths
International audienceAn inversion method based on a neural network was used to estimate water and dry matter contents on plant leaves, from transmittance and reflectance measurements, using light emitting diodes (LEDs) at specific wavelengths in NIR and FIR. The preliminary results for the predicted water content by the neural network method showed a RMSE value of 0.0027 g/cm(2) and vertical bar sigma vertical bar value of approximately 3.53%, computed on 127 plant leaf samples over 51 species. Dry matter estimation also was performed, which showed potential implementation after future improvements. We believe this inversion method could be implemented in a portable system based on any silicon platform with the capability to perform in situ measurements on plant tissue. (C) 2015 Optical Society of Americ
Outdoor Recreation in Southeastern United States National Forests: An Investigation of the Influence of Ethnicity and Gasoline Price on Individual Participation
Outdoor recreation is one of the most widely recognized ecosystem services provided by forests and grasslands in the world. This paper examined the influence of factors not related to landscape values, such as ethnicity and gasoline prices, on individual participation in outdoor recreation in the southeastern region of the U.S. The model results showed that there were no significant (p > 0.05) differences between the race groups (Caucasians and non-Caucasians) for participation in the different activities either between racial groups or among National Forest (NF). This may be due to the very high proportion of Caucasian participants in the study. The results also revealed that travel costs negatively influence the number of NF visits. The number of NF visits decreases if the gasoline price increases by 20% and more. The results of this study have practical importance for different entities such as stakeholders, tourism operators, the United States Department of Agriculture (USDA) Forest Service, and local authorities
Identifying Primary Drivers of Participants from Various Socioeconomic Backgrounds to Choose National Forest Lands in the Southeastern Region of the US as a Travel Destination for Recreation
Growing demand for National Forests (NFs) recreational activities makes it crucial to understand the attitudes towards valuing public recreational resources and the potential conflicts with other functions of the forests. The study was conducted to identify the primary drivers influencing individual participation in outdoor recreation on NF lands in the southeastern region of the US among participants of various socioeconomic backgrounds. The study was based on the 2010–2014 dataset of fourteen NFs across thirteen states in the Southeastern USA—retrieved from the United States Department of Agriculture (USDA). Different statistical models and statistical analyses were utilized for the study. The statistical results revealed that individual needs for relaxation were the main driver for participation in forest recreation for the whole sample and pulled data (approximately 52% of the participants). It has been noted that the drivers varied depending on the forest. The personal need for mental development was the least valued driver with only 2%. Some significant differences were observed by gender, age category, and income level. The study results have practical importance for different stakeholders such as tourism operators, the USDA Forest Service, and local authorities