168 research outputs found
Developmental system drift and flexibility in evolutionary trajectories
The comparative analysis of homologous characters is a staple of evolutionary developmental biology and often involves extrapolating from experimental data in model organisms to infer developmental events in non-model organisms. In order to determine the general importance of data obtained in model organisms, it is critical to know how often and to what degree similar phenotypes expressed in different taxa are formed by divergent developmental processes. Both comparative studies of distantly related species and genetic analysis of closely related species indicate that many characters known to be homologous between taxa have diverged in their morphogenetic or gene regulatory underpinnings. This process, which we call “developmental system drift” (DSD), is apparently ubiquitous and has significant implications for the flexibility of developmental evolution of both conserved and evolving characters. Current data on the population genetics and molecular mechanisms of DSD illustrate how the details of developmental processes are constantly changing within evolutionary lineages, indicating that developmental systems may possess a great deal of plasticity in their responses to natural selection
Drosophila tan Encodes a Novel Hydrolase Required in Pigmentation and Vision
Many proteins are used repeatedly in development, but usually the function of the protein is similar in the different contexts. Here we report that the classical Drosophila melanogaster locus tan encodes a novel enzyme required for two very different cellular functions: hydrolysis of N-β-alanyl dopamine (NBAD) to dopamine during cuticular melanization, and hydrolysis of carcinine to histamine in the metabolism of photoreceptor neurotransmitter. We characterized two tan-like P-element insertions that failed to complement classical tan mutations. Both are inserted in the 5′ untranslated region of the previously uncharacterized gene CG12120, a putative homolog of fungal isopenicillin-N N-acyltransferase (EC 2.3.1.164). Both P insertions showed abnormally low transcription of the CG12120 mRNA. Ectopic CG12120 expression rescued tan mutant pigmentation phenotypes and caused the production of striking black melanin patterns. Electroretinogram and head histamine assays indicated that CG12120 is required for hydrolysis of carcinine to histamine, which is required for histaminergic neurotransmission. Recombinant CG12120 protein efficiently hydrolyzed both NBAD to dopamine and carcinine to histamine. We conclude that D. melanogaster CG12120 corresponds to tan. This is, to our knowledge, the first molecular genetic characterization of NBAD hydrolase and carcinine hydrolase activity in any organism and is central to the understanding of pigmentation and photoreceptor function
Methods of the Michigan State University Motor Performance Study
The Michigan State University Motor Performance Study (MPS) was initiated in 1967 and lasted 32 years. Three central components existed: 1) Educational component, in which students experienced applied work with youth; 2) Instructional component, whereby enrolled youth received sport-specific skill instruction; and 3) Research component. The primary goals of the research component of the MPS were to examine: 1) the changes over time that occur in the physical growth, biological maturity, and motor skill acquisition of children and youth; 2) the processes involved in the attainment of basic and complex motor skills; and 3) the influence of changes in the learners’ environment on their rates of motor skill acquisition. Several growth and maturation, motor competence, and physical performance/fitness variables were collected, and a follow-up study examined participants’ adult physical activity, sport participation, and health outcomes. This manuscript describes methods used in the research component of the MPS and the follow-up
An Examination of Sport Participation Tracking and Adult Physical Activity for Participants of the Michigan State University Motor Performance Study
Research tracking sport participation from youth to adulthood is relatively rare, as is research that tracks youth sport participation with regard to adult physical activity (PA) levels, especially in the United States. Aims of this study were: 1) To investigate the degree to which sport participation tracked across youth, adolescence, and early adulthood in a sample of participants from the Michigan State University Motor Performance Study (MPS), and 2) Determine if differences existed in their levels of adult PA relative to prior sport participation. In total, 256 (60.8%) former participants from the MPS completed follow-up surveys regarding routine sport participation and PA across the previous year. Sport participation tracked consistently from youth to college. Further, regardless of the level of youth sport participation, adult leisure time PA was relatively consistent among groups. Although the study did not directly test the influence of the MPS on subsequent adult outcomes, our findings suggest that participants’ past sport participation was not a good predictor of adult PA for those who were involved in a program that emphasized fundamental motor skills in youth. Further investigation of such programs can help to better inform their influence on adult PA
Renal Cell Carcinoma with Angioleiomyoma-Like Stroma and Clear Cell Papillary Renal Cell Carcinoma: Exploring SDHB Protein Immunohistochemistry and the Relationship to Tuberous Sclerosis Complex
Renal cell carcinoma (RCC) with angioleiomyoma-like stroma appears to be molecularly distinct from clear cell RCC; however, its relationship to clear cell papillary RCC remains debated. Recent studies have found that similar tumors sometimes occur in patients with tuberous sclerosis complex (TSC), of which one study found unexpectedly negative succinate dehydrogenase (SDH) B immunostaining. We evaluated immunohistochemistry for SDHB in 12 apparently sporadic RCCs with angioleiomyoma-like stroma and correlated with clinical information for stigmata of TSC. Tumors were compared to a group of 16 clear cell papillary RCCs and 6 unclassified tumors with prominent stroma. With exception of 1 unclassified tumor, all exhibited at least focal cytoplasmic staining for SDHB protein, often requiring high magnification and better appreciated with increased antibody concentration. Detailed history information was available for 9/12 patients with smooth muscle-rich tumors, revealing no stigmata of undiagnosed TSC. Electron microscopy performed on 1 of these tumors revealed mitochondria to be very sparse, potentially accounting for the weak immunohistochemical labeling for SDHB protein. Weak SDHB immunostaining may represent another shared feature of RCC with angioleiomyoma-like stroma and clear cell papillary RCC, likely due to sparse mitochondria, strengthening the possible relationship of these entities. Although smooth muscle-rich tumors have been recently reported in patients with TSC, absence of staining in tumors with this pattern may not be specific for TSC. In tumors with pale or clear cytoplasm, immunohistochemical staining for SDHB should be interpreted with caution as evidence of abnormality in the SDH pathway
Blueberry Research Progress Report
The 1976 edition of the Blueberry Research Progress Report was prepared for the Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Effect of Plant-Water Stress on Lowbush Blueberry Growth, Yield and Quality
2. Insects Affecting the Blueberry
3. The Development of Blueberry Varieties Adapted to Maine
4. Weed Control in Blueberry Fields
5. Pruning of Blueberries
6. Integrated Management of Blueberry Fields
7. The Physiology and Biochemistry of the Development of the Lowbush Blueberry Fruit
8. Survey of Red Leaf Disease of Blueberries
9. Blossom Blight of Blueberries
10. Blueberry Marketing and Cost Analysis of Producing Blueberries
11. Factors Regulating Rhizome Initiation and Development in the Lowbush Blueberry
12. New Food Products and Servic
Blueberry Research Progress Report
The 1975 edition of the Blueberry Research Progress Report was prepared for the Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include:
1. Insects Affecting the Blueberry
2. Weed Control in Blueberry Fields
3. Pruning of Blueberries
4. Integrated Management of Blueberry Fields
5. Selective Thinning of Black Barrenberries in Lowbush Blueberry Fields with Ethrel
6. The Physiology and Biochemistry of the Development of the Lowbush Blueberry Fruit
7. The Development of Blueberry Varieties Adapted to Maine
8. Factors Regulating Rhizome Initiation and Development in the Lowbush Blueberry
9. Mechanical Blueberry Harvesting
10. Blueberry Marketing and Cost Analysis of Producing Blueberries
11. New Food Products and Servic
Global public policy, transnational policy communities, and their networks
Public policy has been a prisoner of the word "state." Yet, the state is reconfigured by globalization. Through "global public–private partnerships" and "transnational executive networks," new forms of authority are emerging through global and regional policy processes that coexist alongside nation-state policy processes. Accordingly, this article asks what is "global public policy"? The first part of the article identifies new public spaces where global policies occur. These spaces are multiple in character and variety and will be collectively referred to as the "global agora." The second section adapts the conventional policy cycle heuristic by conceptually stretching it to the global and regional levels to reveal the higher degree of pluralization of actors and multiple-authority structures than is the case at national levels. The third section asks: who is involved in the delivery of global public policy? The focus is on transnational policy communities. The global agora is a public space of policymaking and administration, although it is one where authority is more diffuse, decision making is dispersed and sovereignty muddled. Trapped by methodological nationalism and an intellectual agoraphobia of globalization, public policy scholars have yet to examine fully global policy processes and new managerial modes of transnational public administration
Comorbidity between alcohol dependence (AD) and nicotine dependence (ND): The genetic contributions from antisocial personality disorder (ASPD) and major depression (MD)
Public opinion and environmental policy output: a cross-national analysis of energy policies in Europe
This article studies how public opinion is associated with the introduction of renewable energy policies in Europe. While research increasingly seeks to model the link between public opinion and environmental policies, the empirical evidence is largely based on a single case: the US. This limits the generalizability of findings and we argue accordingly for a systematic, quantitative study of how public opinion drives environmental policies in another context. Theoretically, we combine arguments behind the political survival of democratic leaders with electoral success and environmental politics. Ultimately, we suggest that office-seeking leaders introduce policies that seem favorable to the domestic audience; if the public prefers environmental protection, the government introduces such policies in turn. The main contribution of this research is the cross-country empirical analysis, where we combine data on the public's environmental attitudes and renewable energy policy outputs in a European context between 1974 and 2015. We show that as public opinion shifts towards prioritizing the environment, there is a significant and positive effect on the rate of renewable energy policy outputs by governments in Europe. To our knowledge, this is the first systematic, quantitative study of public opinion and environmental policies across a large set of countries, and we demonstrate that the mechanisms behind the introduction of renewable energy policies follow major trends across European states
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