Virtual Plant Clinics Cultivate Collaborations and Transfer Knowledge in Extension

Plant clinics have been used as a tool to help Extension professionals diagnose crop production problems; however, limited resources have made it difficult to continue to offer in-person clinics. Using distance-learning technology, University of Maryland Extension initiated and offered to Extension professionals virtual plant clinics (VPCs) during the 2017 and 2018 growing seasons. Participants reported an increase in knowledge of field conditions across the state and felt that they were more likely to attend a VPC over an in-person clinic. Hosting VPCs is a way for Extension faculty to increase internal communication, share ideas throughout the growing season, and foster collaborations

General Recommendations for Managing Nematodes in Field Crops

Nematodes are an economically important pathogen of many crops in Maryland. Significant yield loss can occur if nematodes are not managed properly. This factsheet serves as a broad introduction to nematodes as plant pathogens and serves as a general guide for sampling and managing nematodes in Maryland

Hardware-Based Security Enhancement for Near Field Communication and Other Close Proximity Inductive-Based Communication Systems

Several hardware-based security improvements to Near Field Communication (NFC) and Radio-Frequency Identification (RFID) systems are developed and presented. The improvements are intended to be used in conjunction with software encryption to ensure robust security. Two main implementations for a more secure NFC or RFID system are presented: a jamming system, and a canceler system. Each implementation improves the security of the system by considerably reducing the distance an outside party can eavesdrop from compared to a standard system. Additionally, each implementation has been shown to be compatible with current NFC standards and specifications. To verify the performance of the security enhancements, full-wave electromagnetic simulations and laboratory experiments were done

What do the numbers really mean? Interpreting variety trial results

Variety trials are conducted across the US by land-grant institutions to evaluate the performance of commercial seed varieties of many crops, such as corn, soybean, wheat, etc. Farmers and other agriculture professionals use this data to help them choose the best seed varieties for their farming operation. Statistics presented in variety trial reports may be unfamiliar to some stakeholders, which can lead to incorrect conclusions. This fact sheet explains the statistics used in variety trials and how to properly apply the statistics to interpret the data

Mineral Resources of the Marble Canyon Wilderness Study Area, White Pine County, Nevada, and Millard County, Utah

The 19,150-acre Marble Canyon Wilderness Study Area (NV-040-086) was evaluated for mineral resources (known) and mineral resource potential (undiscovered), and field work was conducted in 1987. The acreage includes 6,435 acres that is now designated as part of the Mount Moriah Wilderness under the Nevada Wilderness Protection Act of 1989 (S. 974), most but not all of which is included in 8,300 acres fro which the U.S. Bureau of Land Management requested a mineral survey. In this report, the wilderness study area, or simply the study area refers to the entire 19,150-acre tract. The area in underlain by quartzite shale and carbonate rocks. The norther Snake Range decollement is a detachment surface within the study area that separates rocks of similar age but different metamorphic grade. Large inferred subeconomic limestone and marble resources i the study area have no special or unique properties. The mineral resource potential for limestone and marble is high in two canyons and is moderate in the rest of the wilderness study area. Parts of the study area above and along the northern Snake Range decollement have low potential for undiscovered deposits of gold, silver, copper, lead, zinc, tungsten, molybdenum, beryllium, and flourite. A zone around barite-bearing rock penetrated by adits inside the southeast boundary of the study area has moderate potential for barite, and the surrounding area has low potential for barite; both areas also have low potential for silver, copper, lead, zinc, and tungsten. The entire study area has moderate potential for oil and gas and low potential for geothermal energy resources

Nonlinear Analysis of the Eckhaus Instability: Modulated Amplitude Waves and Phase Chaos with Non-zero Average Phase Gradient

We analyze the Eckhaus instability of plane waves in the one-dimensional complex Ginzburg-Landau equation (CGLE) and describe the nonlinear effects arising in the Eckhaus unstable regime. Modulated amplitude waves (MAWs) are quasi-periodic solutions of the CGLE that emerge near the Eckhaus instability of plane waves and cease to exist due to saddle-node bifurcations (SN). These MAWs can be characterized by their average phase gradient $\nu$ and by the spatial period P of the periodic amplitude modulation. A numerical bifurcation analysis reveals the existence and stability properties of MAWs with arbitrary $\nu$ and P. MAWs are found to be stable for large enough $\nu$ and intermediate values of P. For different parameter values they are unstable to splitting and attractive interaction between subsequent extrema of the amplitude. Defects form from perturbed plane waves for parameter values above the SN of the corresponding MAWs. The break-down of phase chaos with average phase gradient $\nu$ > 0 (``wound-up phase chaos'') is thus related to these SNs. A lower bound for the break-down of wound-up phase chaos is given by the necessary presence of SNs and an upper bound by the absence of the splitting instability of MAWs.Comment: 24 pages, 14 figure

Forecasting the SST space-time variability of the Alboran Sea with genetic algorithms

We propose a nonlinear ocean forecasting technique based on a combination of genetic algorithms and empirical orthogonal function (EOF) analysis. The method is used to forecast the space-time variability of the sea surface temperature (SST) in the Alboran Sea. The genetic algorithm finds the equations that best describe the behaviour of the different temporal amplitude functions in the EOF decomposition and, therefore, enables global forecasting of the future time-variability.Comment: 15 pages, 3 figures; latex compiled with agums.st

Modulated Amplitude Waves and Defect Formation in the One-Dimensional Complex Ginzburg-Landau Equation

The transition from phase chaos to defect chaos in the complex Ginzburg-Landau equation (CGLE) is related to saddle-node bifurcations of modulated amplitude waves (MAWs). First, the spatial period P of MAWs is shown to be limited by a maximum P_SN which depends on the CGLE coefficients; MAW-like structures with period larger than P_SN evolve to defects. Second, slowly evolving near-MAWs with average phase gradients $\nu \approx 0$ and various periods occur naturally in phase chaotic states of the CGLE. As a measure for these periods, we study the distributions of spacings p between neighboring peaks of the phase gradient. A systematic comparison of p and P_SN as a function of coefficients of the CGLE shows that defects are generated at locations where p becomes larger than P_SN. In other words, MAWs with period P_SN represent ``critical nuclei'' for the formation of defects in phase chaos and may trigger the transition to defect chaos. Since rare events where p becomes sufficiently large to lead to defect formation may only occur after a long transient, the coefficients where the transition to defect chaos seems to occur depend on system size and integration time. We conjecture that in the regime where the maximum period P_SN has diverged, phase chaos persists in the thermodynamic limit.Comment: 25 pages, 18 figure