Bayesian classification and unsupervised learning for isolating weeds in row crops

This paper presents a weed/crop classification method using computer vision and morphological analysis. Subsequent supervised and unsupervised learning methods are applied to extract dominant morphological characteristics of weeds present in corn and soybean fields. The novelty of the presented technique resides in the feature extraction process that is based on spatial localization of vegetation in fields. Features from the weed leaf area distribution are extracted from the cultivation inter-rows, then features from the crop are inferred from the mixture model equation. Those extracted features are then passed to a naive bayesian classifier and a gaussian mixture clustering algorithm to discriminate weed from crop plant. The presented technique correctly classifies an average of 94 % of corn and soybean plants and 85 % of the weed (multiple species) without any prior knowledge on the species present in the field.     

Controlling stabilization of oil-in-water emulsions with lignins through fractionation,functionalization, and formulation

Lignins, heterogeneous assemblies of polyphenolic oligomers present in lignocellulosic plant biomass, are valorized mainly by combustion because of their low solubility in commonly used solvents. However, in addition to antioxidant, anti-UV and antimicrobial properties, and marked interfacial properties are part of lignins physicochemical properties, thus making them good candidates for sustainable colloids. It is hypothesized that lignins solubility and emulsifying performances could be modulated by fractionation, functionalization, and formulation strategies. The importance of the solvent, and of the pH on lignins solubilization in aqueous phase was investigated. Accordingly, simple O/W emulsions stabilized by different lignins were designed and characterized. The whole results demonstrated that lignins solubility in water can be optimized using appropriate co-solvent and pH readjustment resulting in a homogeneous dispersion with only 7.2 ± 1.8% wt/wt of insoluble lignins. Both fractionation and biocatalytic modification of lignins allowed increasing stabilization of the oil–water interface by limiting coalescence (23%–24% of relative increase of the D90) compared with non-fractionated lignins (32%), thus advocating their potential use as multifunctional emulsion stabilizers. As a result, a direct link between the molar mass profile of lignins and their ability to stabilize the oil–water interface as well as to reduce emulsion's sedimentation could be established.     

Non‐destructive measurement of vitamin C,total polyphenol and sugar content in apples using near‐infrared spectroscopy

BACKGROUND: The vitamin C and polyphenol content of apples constitute quality and nutritional parameters of great interest for consumers, especially in terms of health. They are commonly measured using laborious reference methods. The purpose of this study was to evaluate the potential of near‐infrared (NIR) spectroscopy as a rapid and non‐destructive method to determine the sugar, vitamin C and total polyphenol content in apples. RESULTS: The quality parameters of more than 150 apple genotypes were analyzed using NIR and reference methods. The results obtained using the least squares support vector machine regression method showed good to very good prediction performance. Low standard error of prediction values, in addition to relatively high ratio to prediction (RPD) values, demonstrated the precision of the models, especially for polyphenol and sugar content. High RPD values (5.1 and 4.3 for polyphenol and sugar, respectively) indicated that an accurate classification of apples based on their content could be achieved. CONCLUSION: NIR spectroscopy coupled with the multivariate calibration technique could be used to accurately measure the quality parameters of apples. In addition, in the case of breeding programs, NIR spectroscopy can be considered an interesting tool for sorting varieties according to a range of concentrations. Copyright © 2012 Society of Chemical Industry     

Trust in the face of conflict: The role of managerial trustworthy behavior and organizational context.

The authors explored the role of attributions in shaping employees' trust in their managers in the context of negative events. The authors examined how 2 forms of managerial trustworthy behavior (open communication and demonstrating concern for employees) and organizational policies relate to attributions, trust in the manager, and organizational citizenship behavior. Participants were 115 credit union employees who responded to a critical incident regarding a disagreement with their managers. As hypothesized, trustworthy behavior was negatively related to attributions of personal responsibility for negative encounters, and this relationship was stronger when human resource policies were perceived as unfair. Managerial trustworthy behavior was also positively related to trust in the manager and organizational citizenship behavior. Personal attributions partially mediated the relationship between trustworthy behavior and trust. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the confusion of "race" with biophysical diversity.

Responds to M. J. Zyphur's (see record 2006-01690-012) comments on the original article by A. Smedley and B. D. Smedley (see record 2005-00117-003). Race, as people live and understand it, inhabits a dimension of reality that transcends biology and cannot be reduced to genes, chromosomes, or even phenotypes. A biological or genetic view of race cannot encompass the lived social reality of race, nor does it represent biogenetic variations in human populations very well (Marks, 1995). As Zyphur notes, biogenetic variations in the human species were produced by evolutionary forces as different groups interacted with and underwent adaptation to the natural environments encountered in their migrations. The result was a pattern of variation that should be familiar to everyone: People with dark skin coloring remained adapted to tropical environments (with some internal variations resulting from amounts of tree cover, land elevation, rainfall, etc.). Peoples of tropical lands thus resemble one another in their varying shades of dark skin color and often curly or frizzy hair (known as polytopicity). Some of the darkest skins are found not in Africa but in India, Sri Lanka, Melanesia, and Northern Australia, as anyone who watched the news coverage of the recent tsunami would readily recognize. Groups migrating beyond the tropical areas gradually lost genes for dark skin as they adapted to cooler climates with less sunlight. Geneticists have shown that just as no two individuals are genetically alike (except for identical twins), no two human groups are precisely alike, even when they derive from a common ancestral population. Biogenetic variation has continued to increase as individuals once widely separated meet and mate. Quite apart from the controversy over races as biological taxa, the idea of race as it is known and lived in American society is composed of social values and meanings imposed on this biological variation over the past three or four centuries. As a social construct, race refers to an ideology. Since the 18th century, Americans and many other people in the world have been conditioned to believe that race as biology is the main source of human identities. As Americans have come into contact with peoples around the world, confusion has inevitably ensued, because U.S. racial categories do not necessarily apply in other countries. Given the complexity of the human genome and the history of (continuous) intermixtures, I doubt if it will ever be possible to correlate our genes with our racial (i.e., social) identities. Nor can I imagine at this point why anyone should want to do so. What service to society or science will this fulfill? Social constructs have their own complex dynamics and are vulnerable to change, just as is any other cultural phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender differences in the adaptive influence of folk beliefs: A longitudinal study of life satisfaction in aging.

Folk beliefs such as "there's a silver lining in every cloud" reflect a positive approach to life that maps onto the notion of interpretive secondary control, and may have consequences for well being. The authors assessed older individuals' agreement with folk beliefs, and examined gender differences in their adaptive implications for well being and positive and negative emotion, both cross-sectionally and longitudinally over 7 years. Following previous research on interpretive secondary control, the authors anticipated that folk beliefs would be (a) more strongly endorsed by or (b) more beneficial to older women than to older men, particularly among those with serious health problems. Although women and men endorsed folk beliefs equally, women benefited more reliably from these beliefs, and women with serious health problems benefited the most. (PsycINFO Database Record (c) 2010 APA, all rights reserved)