Identification of Sources of Bacterial Wilt Resistance in Common Bean (\u3ci\u3ePhaseolus vulgaris\u3c/i\u3e)

Over the last decade, bacterial wilt, caused by Curtobacterium flaccumfaciens pv. flaccumfaciens, has reemerged in the Central High Plains (Nebraska, Colorado, and Wyoming) and has been identified in almost 500 fields. Affected fields were planted with bean (Phaseolus vulgaris) from multiple market classes and seed sources, including yellow, great northern, pinto, kidney, cranberry, black, navy, pink, and small red, and incidence varied from trace levels to \u3e90%. One wiltresistant bean, ‘Emerson’, is available today but it is grown on a limited basis as a specialized cultivar for targeted markets in Europe and cannot be grown in all fields where the disease has recently been identified. Thus, we are faced with an emerging problem that must be addressed by utilizing newly developed resistant cultivars. This study was initiated to evaluate the Phaseolus National Plant Germplasm System (NPGS) bean collection for resistance to C. flaccumfaciens pv. flaccumfaciens in the ongoing effort to develop a new wilt-resistant cultivar adapted to this region. In total, 467 entries, including accessions from the NPGS, several commercial great northern and pinto cultivars, and University of Nebraska experimental lines, were screened with a highly virulent orange strain of C. flaccumfaciens pv. flaccumfaciens previously recovered from an infected great northern bean plant in Nebraska. Bacterial wilt severity ratings were 1.0 to 9.0 (0 to 90% incidence). Of the 427 accessions from the NPGS, only 1 showed resistance (0.23%), 19 showed intermediate resistances (4.45%), and the remainder were susceptible (95.34%). PI 325691 was identified as a source of bacterial wilt resistance. It was screened against six additional C. flaccumfaciens pv. flaccumfaciens strains and still produced resistant reactions. PI 325691 is a wild common bean (P. vulgaris) collected 8 miles South of Tzitzio, Michoacán, Mexico; however, it has a small seed size (5.3 g 100–1 seeds) that is commercially unacceptable. It will take several backcrosses to transfer this resistance to bacterial wilt and recover the seed size into a cultivated bean

Mathematical models of bipolar disorder

We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using weakly-coupled, weakly-damped harmonic oscillators. We discuss how the proposed models can be used as a framework for refined models that incorporate additional biological data. We conclude with a discussion of possible generalizations of our work, as there are several biologically-motivated extensions that can be readily incorporated into the series of models presented here

Abiotic Diseases of Dry Beans

The environment plays a major role in the process of infection and disease development in plants by providing the conditions necessary for pathogens to cause disease. However, adverse environmental conditions or genetic abnormalities also may be responsible for plant damage. This type of damage often is referred to as abiotic disease or stresses. Many of the symptoms of these “diseases” may be confused with true dry bean diseases, thus this publication is designed to educate those working with dry bean on how to recognize abiotic problems and avoid unnecessary disease treatments. Genetic Disorders The genetic abnormalities leading to changes in color in dry beans include chimeras, leaf spotting, yellowing. or production of albino plants or seedlings. Chimeras are among the most common genetic disorders. These aberrations, which may be inherited, result from a single site (point) cell mutation or from outcrossing during seed production. They may occur any time in the season. In leaf tissues, they cause a loss of chlorophyll, giving the leaf a white to yellow variegation (Figure 1). General chlorosis or yellowing traits (Figure 2) also may be inherited and are not likely to cause significant damage. However, the albino seedlings that may be observed early in the season, usually do not survive due to a deficiency of chlorophyll (Figure 3)

Bacterial Wilt of Dry Beans in Western Nebraska

Bacterial wilt of dry beans has reappeared in Nebraska dry bean fields. This NebGuide addresses symptoms and identification, life cycle, and management of bacterial wilt in dry beans. Bacterial wilt of dry beans, caused by Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), has been a sporadic — but often serious — production problem in dry beans throughout the irrigated High Plains since first being reported in South Dakota in 1922. It was first observed in western Nebraskadry bean production fields in the earlymid 1950s, and continued to be an endemic, economically important problem throughout the 1960s and early 1970s. The disease then only periodically appeared in seed, but had little detectable effect on yields after the implementation of crop rotation and seed sanitation practices The pathogen was again identified in 2003 for the first time in this area in almost 25 years. Over the last seven to eight years, it has fully re-emerged in the Central High Plains (Nebraska, Colorado, and Wyoming) and has now been identified from more than 400 fields. Affected fields were planted with dry beans from multiple market classes and seed sources, including yellows, great northern, pintos, kidneys, cranberries, blacks, navies, pinks, and small reds. Disease incidence in these fields has varied from trace levels to \u3e90 percent

Determining water use of sorghum from two-source energy balance and radiometric temperatures

Estimates of surface actual evapotranspiration (ET) can assist in predicting crop water requirements. An alternative to the traditional crop-coefficient methods are the energy balance models. The objective of this research was to show how surface temperature observations can be used, together with a two-source energy balance model, to determine crop water use throughout the different phenological stages of a crop grown. Radiometric temperatures were collected in a sorghum (<i>Sorghum bicolor</i>) field as part of an experimental campaign carried out in Barrax, Spain, during the 2010 summer growing season. Performance of the Simplified Two-Source Energy Balance (STSEB) model was evaluated by comparison of estimated ET with values measured on a weighing lysimeter. Errors of ±0.14 mm h<sup>−1</sup> and ±1.0 mm d<sup>−1</sup> were obtained at hourly and daily scales, respectively. Total accumulated crop water use during the campaign was underestimated by 5%. It is then shown that thermal radiometry can provide precise crop water necessities and is a promising tool for irrigation management

Building a community learning culture

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2007.Includes bibliographical references (p. 183-188).The complexity of the school, society and policy, and dominant cultural beliefs about teaching, learning, and knowledge constrain people's mindsets, paradoxically preventing the fundamental changes that can take advantage of new technologies and address the inadequacies of current educational systems. The same constraints permeate reform efforts as most often the educational establishment tests the transformation of the system one element at a time while attempting to hold all other elements constant, thereby inhibiting more profound changes. The promise of one-to-one computer infrastructure provides such a dramatic alternative to current educational systems that it forces us to think about change at a deeper level, leaving us with the challenge of where to begin. The fundamental aim of this thesis is to study the potential of the one-to-one computer infrastructure as a catalyst for change. This thesis presents a holistic model for rural school that builds on a rich body of Constructionist learning research. Key components of the holistic model are: sufficient amount of student-owned technology which can accompany them as they interact at home and in the broader community; activities that are designed with sufficient scope to encourage the appropriation of powerful ideas; and, teacher engagement in activity design with simultaneous support from a knowledge network of local and international colleagues and mentors. I introduce the concept of "whole-project" learning, which strategically integrates the elements of the model, and introduces a learning approach that is fundamentally different from the existent methodology of work.(cont.) The thesis findings rely on data collected during the one year intervention. This longitudinal study of a one-teacher school in Costa Rica over the course of the year allows me to present stories of change as well as a more quantitative analysis of the learning activities. The results of the study suggest that in order for appropriation to occur, three conditions are salient: computational technology must be mobile and owned by the students so that learning becomes integral to the culture of the community; activities need to be of a scale and quality that children and teachers can make rich connections to powerful ideas; and, participation and voice must be inclusive.by Claudia M. Urrea.Ph.D

Problematic Smartphone Use in Spanish and Italian University Students

Sustainable education requires the proper usage of technological devices. Among these is the smartphone, which is used by millions of young people around the world in today’s society. The objective of this study was to understand the smartphone usage profile of Spanish and Italian university students. It also aimed to identify possible problematic uses, and the differences in smartphone use (or abuse) between the participating subjects. The study was descriptive and comparative, with the intentional sampling of N = 1412 subjects studying at the education faculties of the University of Alicante (UA) and the Suor Orsola Benincasa University (UNISOB). A previously-validated questionnaire with 27 items was employed during the 2019–20 academic year. The data was analysed using the SPSS 25 programme. Descriptive and inferential analyses were carried out. The results obtained after the analysis of the data indicated that, of the four possible user types—occasional, habitual, at risk, and problematic—more than half of the sample identified themselves as habitual users. It can be concluded that there are significant differences between the universities: the UA students exhibited more problematic use than the UNISOB students. It is therefore necessary to prepare training programmes that are designed to avert problematic behaviours related to smartphone use.This work was supported by the Program Redes-I3CE of the Deputy Vice-Chancellor’s Office for Quality and Innovation of the University of Alicante, under Grant 4676—Smartphones as a resource for initial teacher training. Mobile learning or addiction? Two of the authors belong to the GIDU-EDUTIC/IN Research Group of the University of Alicante (VIGROB-330), and one author belongs to the GITE Research Group of the University of Murcia