Crop phenology literature review for corn, soybean, wheat, barley, sorghum, rice, cotton, and sunflower

There are no author-identified significant results in this report

Crop yield literature review for AgRISTARS crops: Corn, soybeans, wheat, barley, sorghum, rice, cotton, and sunflowers

There are no author-identified significant results in this report

Use of NOAA-N satellites for land/water discrimination and flood monitoring

A tool for monitoring the extent of major floods was developed using data collected by the NOAA-6 advanced very high resolution radiometer (AVHRR). A basic understanding of the spectral returns in AVHRR channels 1 and 2 for water, soil, and vegetation was reached using a large number of NOAA-6 scenes from different seasons and geographic locations. A look-up table classifier was developed based on analysis of the reflective channel relationships for each surface feature. The classifier automatically separated land from water and produced classification maps which were registered for a number of acquisitions, including coverage of a major flood on the Parana River of Argentina

Preliminary evaluation of spectral, normal and meteorological crop stage estimation approaches

Several of the projects in the AgRISTARS program require crop phenology information, including classification, acreage and yield estimation, and detection of episodal events. This study evaluates several crop calendar estimation techniques for their potential use in the program. The techniques, although generic in approach, were developed and tested on spring wheat data collected in 1978. There are three basic approaches to crop stage estimation: historical averages for an area (normal crop calendars), agrometeorological modeling of known crop-weather relationships agrometeorological (agromet) crop calendars, and interpretation of spectral signatures (spectral crop calendars). In all, 10 combinations of planting and biostage estimation models were evaluated. Dates of stage occurrence are estimated with biases between -4 and +4 days while root mean square errors range from 10 to 15 days. Results are inconclusive as to the superiority of any of the models and further evaluation of the models with the 1979 data set is recommended

Simulação da dinâmica do carbono orgânico em latossolo sob plantio direto e convencional: uma análise dos modelos CENTURY e CQESTR.

O objetivo deste trabalho foi avaliar a performance dos modelos Century e CQESTR em simular a dinâmica do carbono orgânico em latossolo vermelho-amarelo sob diferentes sistemas de preparo em àreas do cerrado do Piauí.Disponível também em papel na biblioteca do CPAMN

CQESTR: a simple model to estimate carbon sequestration in tropical soils.

CQESTR simulates the effect of management practices on soil organic carbon (SOC) stocks. The beta version of the model had been calibrated and validated for temperate regions. Our objective was to evaluate the CQESTR model performance for simulating carbon dynamics as affected by tillage practices in two tropical soils (Ultisol and Oxisol) in southeastern and northeastern Brazil. In the southeast (20.75 S 42.81 W), tillage systems consisted of no tillage (NT); reduced tillage (RT) (one disc plough and one harrow leveling [RT1] or one heavy disc harrow and one harrow leveling [RT2]); and conventional tillage (CT) (two heavy disc harrows followed by one disc plough and two harrow levelings). In the northeast (7.55 S 45.23 W), tillage systems consisted of NT, RT (one chisel plow and one harrow leveling), and CT (one disk plow, two heavy disk harrowings, and two harrow levelings). CQESTR underestimated SOC at both sites, especially under NTsystems, indicating that adjustments (e.g., the inclusion of clay mineralogy factor) are necessary for more accurate simulation of SOC in the tropics. In spite of this, measured and simulated values of SOC in the 0?20 cm depth were well correlated (southeast, R2 =0.94, p<0.01; northeast, R2=0.88, p<0.05). The model estimated carbon emissions varying from 0.36 (NT) to 1.05 Mg ha-1 year-1 (CT) in the southeast and from 0.30 (NT) to 0.82 (CT) Mg ha-1 year-1 in the northeast. CQESTR showed acceptable performance to predict SOC dynamics in two tropical soils of Brazil.1 CD-ROM

Hierarchies and Ranks for Persistence Pairs

We develop a novel hierarchy for zero-dimensional persistence pairs, i.e., connected components, which is capable of capturing more fine-grained spatial relations between persistence pairs. Our work is motivated by a lack of spatial relationships between features in persistence diagrams, leading to a limited expressive power. We build upon a recently-introduced hierarchy of pairs in persistence diagrams that augments the pairing stored in persistence diagrams with information about which components merge. Our proposed hierarchy captures differences in branching structure. Moreover, we show how to use our hierarchy to measure the spatial stability of a pairing and we define a rank function for persistence pairs and demonstrate different applications.Comment: Topology-based Methods in Visualization 201

modelagem da dinâmica da matéria orgânica do solo em sistema integração lavoura-pecuária usando CQESTR.

O sistema Integração Lavoura-Pecuária tem sido considerado como alternativa para a melhoria da qualidade do solo especialmente para áreas do cerrado brasileiro. Para verificar o impacto, em médio e longo prazos, de sistemas de manejo sobre a dinâmica da matéria orgânica do solo, tem sido recomendado o uso de modelos de simulação. CQESTR é um modelo mecanístico, considerado simples, pois requer menor número de variáveis de entrada e tem sido calibrado e validado apenas para região temperada. Os objetivos deste estudo foram: a) comparar estoques de carbono medidos por meio de método analítico e simulados pelo modelo CQESTR e; b) avaliar o efeito do Sistema Integração Lavoura-Pecuária sobre a dinâmica da matéria orgânica do solo por meio do modelo CQESTR. A área em estudo, sob floresta nativa de cerrado até 1983, foi cultivada com soja em sistema convencional por 10 anos, até a instalação do experimento, em 1993. Os sistemas estudados foram: Integração Lavoura-Pecuária com rotação (soja-milho/braquiária) a cada 4 anos (ILP4); Integração Lavoura-Pecuária com rotação (sojamilho/braquiária) a cada 2 anos (ILP2); Plantio direto com rotação soja-milho (PD-SM); Integração Lavoura- Pecuária com rotação (arroz/braquiária) a cada 3 anos (ILP3) em plantio convencional; Plantio convencional sob cultivo do arroz (PC-A). Com exceção do sistema ILP3, CQESTR superestimou os estoques de carbono orgânico. No entanto as diferenças entre valores medidos e simulados foram pequenas, variando de 0,1 (PD-SM) a 15% (PC-A) o que demonstra o potencial do modelo em simular dinâmica da matéria orgânica em solo tropical. Os sistemas ILP4 e ILP2 apresentaram tendência para aumento dos estoques de carbono em médio e longo prazos e podem ser considerados estratégias de manejo para melhoria da qualidade do solo e seqüestro de carbono em áreas do cerrado brasileiro.1 CD-ROM

A Clinical Trial to Validate Event-Related Potential Markers of Alzheimer\u27s Disease in Outpatient Settings

INTRODUCTION: We investigated whether event-related potentials (ERP) collected in outpatient settings and analyzed with standardized methods can provide a sensitive and reliable measure of the cognitive deficits associated with early Alzheimer\u27s disease (AD). METHODS: A total of 103 subjects with probable mild AD and 101 healthy controls were recruited at seven clinical study sites. Subjects were tested using an auditory oddball ERP paradigm. RESULTS: Subjects with mild AD showed lower amplitude and increased latency for ERP features associated with attention, working memory, and executive function. These subjects also had decreased accuracy and longer reaction time in the target detection task associated with the ERP test. DISCUSSION: Analysis of ERP data showed significant changes in subjects with mild AD that are consistent with the cognitive deficits found in this population. The use of an integrated hardware/software system for data acquisition and automated data analysis methods make administration of ERP tests practical in outpatient settings