483 research outputs found

    Passive high ratio sunlight concentration configurations

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    During the day the sun is moving along curved 1-D trajectory across the sky. This is essential a priori information that can be used in order to design passive optics to perform efficient collection of sunlight without tracking after sun’s location in the sky. Despite the movement of the sun along its trajectory the optics will collect the energy to the same spatial location where the photo-voltaic cell is positioned. Two novel designs are proposed while the first one is based on waveguides and the second on prisms with high concentration ratio of above 10X. The proposed configurations are validated numerically and experimentally

    Physiological and genetic aspects of a diploid potato population in the Netherlands and Northern Finland

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    Tuberization of potatoes exposed to different photoperiod regimes has been earlier investigated in several studies. However, there is still a limited understanding of the entire tuberization process and the factors influencing this process. One of the constraints of the previous studies has been the use of only one or a few genotypes. Furthermore, the experimental designs have not utilised the natural growing conditions with continuous changes in daylength during the growing season. The general aim of the project was to study the developmental dynamics of the broad-based potato (Solanum tuberosum L.) (CxE) population development at different climatical regimes under the very long-day, long-day and short conditions in Finland, the Netherlands and Ecuador/Venezuela, respectively. In this paper we are presenting some of the results achieved in the studies in Finland during the growing season 2004. In addition to population level trait characteristics we also describe here some of the identified QTLs (quantitative trait loci) for stolon related and tuber formation traits. In some cases we also compare the expression of some of the traits both in Finland and Netherlands.The main difference between the CxE population grown in Finland and the Netherlands was that the onset of flowering took place one week later in Finland. The relationship between tuber initiation and onset of flowering differed depending on the day length. In Finland approximately 70 % of the genotypes had swollen stolon tips before the onset of flowering, while in the Netherlands only 30 % of the genotypes had reached this condition. We also found numerous different trait linked QTLs, for example, a QTL associated with tuber formation was identified on chromosome E5, and QTLs associated with stolon characteristics on chromosomes E1, E4, E10 and E12. As a conclusion, the present preliminary results provide a good basis for determining the influence of different environmental conditions on potato development. In addition, the QTLs obtained in this study give a better understanding of the genetics of complex characters, and can be used in improving the potato crop in breeding programs

    Only Yes Means Yes: Sexual Coercion in Rural Adolescent Relationships

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    Purpose Sexual consent is important to healthy relationships; however, sexual coercion is common. We examine modifiable risk and protective factors for sexual coercion among high school students in a rural community. Methods We surveyed 10th graders (N = 442) in a rural, Midwestern, low-to-middle income county before receiving an evidence-based sex education program. Sexual coercion was a single item, “has anyone you were dating or going out with forced you to do sexual things that you did not want to do?” We examined associations between sexual coercion and demographics, risk behaviors, sexual self-efficacy, controlling relationship behaviors, parent communication, and adverse childhood experiences. Results Approximately 22% of females and 8% of males reported experiencing sexual coercion at least once in their lifetime. Gender differences emerged in associated risk and protective factors, including sexual sex efficacy, controlling relationship behaviors, parent–adolescent communication about sex, and adverse childhood experiences. Conclusions Sexual coercion is common among adolescents in rural communities. Prevention interventions should target modifiable risk and protective factors

    The origin of slow electron recombination processes in dye-sensitized solar cells with alumina barrier coatings

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    We investigate the effect of a thin alumina coating of nanocrystalline TiO2 films on recombination dynamics of dye-sensitized solar cells. Both coated and uncoated cells were measured by a combination of techniques: transient absorption spectroscopy, electrochemical impedance spectroscopy, and open-circuit voltage decay. It is found that the alumina barrier reduces the recombination of photoinjected electrons to both dye cations and the oxidized redox couple. It is proposed that this observed retardation can be attributed primarily to two effects: almost complete passivation of surface trap states in TiO2 that are able to inject electrons to acceptor species, and slowing down by a factor of 3–4 the rate of interfacial charge transfer from conduction-band [email protected]

    Dynamics of senescence-related QTLs in potato

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    The study of quantitative trait's expression over time helps to understand developmental processes which occur in the course of the growing season. Temperature and other environmental factors play an important role. The dynamics of haulm senescence was observed in a diploid potato mapping population in two consecutive years (2004 and 2005) under field conditions in Finland. The available time series data were used in a smoothed generalized linear model to characterize curves describing the senescence development in terms of its onset, mean and maximum progression rate and inflection point. These characteristics together with the individual time points were used in a Quantitative trait loci (QTL) analysis. Although QTLs occurring early in the sene

    Tapping into Community Resiliency in Rural Adolescent Pregnancy Prevention: An Implementation Sciences Approach

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    Although rural youth experience marked inequities in adolescent pregnancy, there is little guidance for implementing evidence-based programs (EBPs) in rural settings. When implementation occurs in rural communities, it frequently focuses on deficits, rather than strengths or capacity for growth. Using the consolidated framework for implementation research (CFIR), we describe a resiliency-focused implementation of two middle school EBPs in rural Midwestern communities, including the intervention, outer and inner settings, individuals, implementation processes and preliminary outcomes. Data included program staff interviews, feedback from local partners, community meetings notes, and participant surveys. Using the CFIR, we describe the engagement of rural communities themselves in a resilience-based implementation of adolescent pregnancy prevention EPBs. Communities self-described as rural, traditional and religious. They identified adolescent pregnancy, substance use, and academic success as priorities. To address infrastructure needs and build on local strengths, funds were used to hire local partners to implement the program. As small communities, stakeholders were closely networked and wanted to address local needs. Local partners selected the EBP based upon community values and priorities. Champions, including local partner organizations and schools were locally based and were well connected. Intensive training of local staff and piloting with adaptation assured fidelity and sustainability, while increasing community implementation skills and comfort. In Clinton County, enrollment was 1946 with students receiving the program in 6th, 7th, and/or 8th grades. In Southern Indiana, 7275 students received the program once in either 6th, 7th, or 8th. We conclude that the CFIR can facilitate the implementation of a community resilience-focused adolescent pregnancy prevention intervention in rural communities

    Manufactured Nano-Objects Confer Viral Protection against Cucurbit Chlorotic Yellows Virus (CCYV) Infecting Nicotiana benthamiana

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    Nanotechnology has emerged as a new tool to combat phytopathogens in agricultural crops. Cucurbit chlorotic yellows virus (CCYV) mainly infects Solanaceae crops and causes significant crop losses. Nanomaterials (NMs) may have efficacy against plant viruses, but the mechanisms underlying complex nanomaterials-plant-virus interactions remain elusive. We challenged Nicotiana benthamiana plants with GFP-tagged CCYV and observed morphological, physiological, and molecular changes in response to 21-d foliar exposure to nanoscale Fe and Zn and C60 fullerenes at 100 mg/L concentration for 21 days. We observed that in response to C60 (100 mg/L) treatment, plants displayed a normal phenotype while the viral infection was not seen until 5 days post-inoculation. On the contrary, Fe and Zn were unable to suppress viral progression. The mRNA transcriptional analysis for GFP and viral coat protein revealed that the transcripts of both genes were 5-fold reduced in response to C60 treatment. Evaluation of the chloroplast ultrastructure showed that NMs treatment maintained the normal chloroplast structure in the plants as compared to untreated plants. C60 upregulated the defense-related phytohormones (abscisic acid and salicylic acid) by 42–43%. Our results demonstrate the protective function of carbon-based NMs, with suppression of CCYV symptoms via inhibition of viral replication and systemic movement
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