1,342 research outputs found

    Herbaceous Filter Strips in Agroecosystems: Implications for Ground Beetle (Coleoptera: Carabidae) Conservation and Invertebrate Weed Seed Predation

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    A 9.3-ha crop field flanked by two filter strips was selected to: 1) assess carabid beetle activity-density and community composition and 2) assess post-dispersal weed seed predation by invertebrates in these habitats. Over- all during 1997 and 1998, 12,937 carabid beetles comprising 58 species were collected. Greater species richness and activity-density was observed in filter strips than in the field. A multivariate ordination revealed that year of capture and habitat were important variables conditioning carabid beetle com­munities. While two omnivorous species known to eat weed seeds [Harpalus erraticus (Say), Anisodactylus sanctaecrucis (F.)] dominated the 1997 captures, two carnivorous [Pterostichus melanarius (Ill), Pterostichus permundus (Say)] were predominant in 1998. Two omnivorous species, Harpalus pensylvanicus (DeG) and H. erraticus, were primarily captured in filter strips. Weed seed removal was greater in filter strips than in the field. This study shows that habitat management represents a feasible approach to con­serve beneficial organisms in farmlands

    Consideraciones ecológicas para el desarrollo de programas de manejo integrado de malezas

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    During the last 60 years, weed management has focused in achieving the goal of eradication of all undesired species, mainly through the use of herbicides. Recently, this approach to weed management has been highly criticized due to its high environmental, social, and economic costs. In response to these objections, there is a growing consensus on the need of developing alternative weed management programs based not only on understanding the factors that condition weed abundance and impact, but the ecological and social consequences of such programs. In this context, integrated weed management can be defined as a decision-making process that coordinates different technological approaches with environmental information and knowledge on weed and crop biology and ecology. This article explores the ecological principles associated with the integrated management of agricultural weeds and discusses the factors that limit the adoption of such programs. Agroecology can contribute to the development of integrated weed management programs if it adopts a holistic perspective on the analysis of the mechanisms determining the abundance, dispersion, and impact of agricultural weeds. Such knowledge should be integrated with educational programs on ecological approaches to weed management that take into account the need and knowledge of the targeted audience.En los últimos 60 años, el manejo de las malezas se ha abocado a la erradicación de las especies no deseadas, principalmente mediante el uso de herbicidas. Recientemente, esta aproximación al manejo de las malezas ha sido altamente criticada por su costo ambiental, social, y económico. En respuesta a dichas objeciones, se ha generado un consenso sobre la necesidad de desarrollar programas alternativos de manejo basados no sólo en el conocimiento de los factores que con- dicionan la abundancia e impacto de las malezas, sino también en las consecuencias ecológicas y sociales de dichas prácticas. En este contexto, el manejo integrado de malezas puede ser definido como un proceso de toma de decisiones que coordina diferentes aproximaciones tecnológicas con información ambiental y conocimiento sobre la biología y ecología de las malezas y los culti- vos. Este artículo explora los principios ecológicos del manejo integrado de malezas y discute los factores que limitan la adopción de dichos programas. La agroecología puede contribuir al de- sarrollo de programas integrados de manejo si adopta una perspectiva holística de los mecanis- mos determinantes de la abundancia, dispersión, e impacto de las malezas. Dicho conocimiento debe ser integrado con programas educativos del manejo ecológico de las malezas que tomen en cuenta las necesidades y el conocimiento de los productores agrícolas

    Herbaceous Filter Strips in Agroecosystems: Implications for Ground Beetle (Coleoptera: Carabidae) Conservation and Invertebrate Weed Seed Predation

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    A 9.3-ha crop field flanked by two filter strips was selected to: 1) assess carabid beetle activity-density and community composition and 2) assess post-dispersal weed seed predation by invertebrates in these habitats. Over- all during 1997 and 1998, 12,937 carabid beetles comprising 58 species were collected. Greater species richness and activity-density was observed in filter strips than in the field. A multivariate ordination revealed that year of capture and habitat were important variables conditioning carabid beetle com­munities. While two omnivorous species known to eat weed seeds [Harpalus erraticus (Say), Anisodactylus sanctaecrucis (F.)] dominated the 1997 captures, two carnivorous [Pterostichus melanarius (Ill), Pterostichus permundus (Say)] were predominant in 1998. Two omnivorous species, Harpalus pensylvanicus (DeG) and H. erraticus, were primarily captured in filter strips. Weed seed removal was greater in filter strips than in the field. This study shows that habitat management represents a feasible approach to con­serve beneficial organisms in farmlands

    AAV5-miHTT gene therapy demonstrates suppression of mutant huntingtin aggregation and neuronal dysfunction in a rat model of Huntington's disease.

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    Huntington's disease (HD) is a fatal progressive neurodegenerative disorder caused by a mutation in the huntingtin (HTT) gene. To date, there is no treatment to halt or reverse the course of HD. Lowering of either total or only the mutant HTT expression is expected to have therapeutic benefit. This can be achieved by engineered micro (mi)RNAs targeting HTT transcripts and delivered by an adeno-associated viral (AAV) vector. We have previously showed a miHTT construct to induce total HTT knock-down in Hu128/21 HD mice, while miSNP50T and miSNP67T constructs induced allele-selective HTT knock-down in vitro. In the current preclinical study, the mechanistic efficacy and gene specificity of these selected constructs delivered by an AAV serotype 5 (AAV5) vector was addressed using an acute HD rat model. Our data demonstrated suppression of mutant HTT messenger RNA, which almost completely prevented mutant HTT aggregate formation, and ultimately resulted in suppression of DARPP-32-associated neuronal dysfunction. The AAV5-miHTT construct was found to be the most efficient, although AAV5-miSNP50T demonstrated the anticipated mutant HTT allele selectivity and no passenger strand expression. Ultimately, AAV5-delivered-miRNA-mediated HTT lowering did not cause activation of microglia or astrocytes suggesting no immune response to the AAV5 vector or therapeutic precursor sequences. These preclinical results suggest that using gene therapy to knock-down HTT may provide important therapeutic benefit for HD patients and raised no safety concerns, which supports our ongoing efforts for the development of an RNA interference-based gene therapy product for HD

    Suppression of MAPK11 or HIPK3 reduces mutant Huntingtin levels in Huntington's disease models.

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    Most neurodegenerative disorders are associated with accumulation of disease-relevant proteins. Among them, Huntington disease (HD) is of particular interest because of its monogenetic nature. HD is mainly caused by cytotoxicity of the defective protein encoded by the mutant Huntingtin gene (HTT). Thus, lowering mutant HTT protein (mHTT) levels would be a promising treatment strategy for HD. Here we report two kinases HIPK3 and MAPK11 as positive modulators of mHTT levels both in cells and in vivo. Both kinases regulate mHTT via their kinase activities, suggesting that inhibiting these kinases may have therapeutic values. Interestingly, their effects on HTT levels are mHTT-dependent, providing a feedback mechanism in which mHTT enhances its own level thus contributing to mHTT accumulation and disease progression. Importantly, knockout of MAPK11 significantly rescues disease-relevant behavioral phenotypes in a knockin HD mouse model. Collectively, our data reveal new therapeutic entry points for HD and target-discovery approaches for similar diseases

    Automated operant assessments of Huntington's Disease mouse models

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    Huntington’s disease (HD) presents clinically with a triad of motor, cognitive, and psychiatric symptoms. Cognitive symptoms often occur early within the disease progression, prior to the onset of motor symptoms, and they are significantly burdensome to people who are affected by HD. In order to determine the suitability of mouse models of HD in recapitulating the human condition, these models must be behaviorally tested and characterized. Operant behavioral testing offers an automated and objective method of behaviorally profiling motor, cognitive, and psychiatric dysfunction in HD mice. Furthermore, operant testing can also be employed to determine any behavioral changes observed after any associated interventions or experimental therapeutics. We here present an overview of the most commonly used operant behavioral tests to dissociate motor, cognitive, and psychiatric aspects of mouse models of HD

    Legacy effects of crop diversity on weed-crop competition in maize production

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    The legacy effects of crop diversity on maize (Zea mays L.) tissue nutrient composition, weed community structure, and intensity of weed-crop competition were assessed through a field experiment at two sites in the northeastern United States. Fields were conditioned with crop diversity gradients from summer 2016 to spring 2019. The crop diversity gradients ranged from a single cultivar to sixteen intercropped cultivars (four species, four cultivars per species) and were established in organic annual and perennial cropping systems. Following the three-year conditioning phase, maize was planted across the entire experiment, and each conditioning-phase diversity treatment was split into weed-free, ambient-weed, moderate-weed, and heavy-weed treatments. Within each cropping system, the effect of crop diversity legacy on weed-crop competition was negligible. In contrast, weed-crop competition varied between the maize grown in soil conditioned by the annual and perennial cropping systems

    Household-scale anaerobic digestion of food waste—a community case study from Bozeman, Montana

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    IntroductionOne-third of food in the United States is wasted, creating significant environmental and social challenges which anaerobic digestion (AD) can address by converting that waste into a nutrient-rich digestate suitable for use as a biofertilizer. While AD is commonly used in municipal and industrial-scale operations for obtaining biogas, household-scale AD to generate of biofertilizer is a promising on-site option without the infrastructure and process complexities associated with large-scale systems.MethodsThis community-based case study investigated the characteristics of food waste and digestate nutrient content from two household-scale AD designs. Digesters were deployed in 12 households (six households used commercial digesters and six used a smaller custom-built prototype) in Bozeman, Montana, USA. Food waste was collected from households, separated by categories, and nutrient content was determined.Results and discussionOver 12 weeks of digester operation, the nutrient content of the digestate was measured. It changed during digester operation with N, P, K, S, pH, and conductivity all increasing (p < 0.05) over time. While food waste C:N ratios varied from 12.1 to 25.7, the C:N ratio of digestate was significantly lower (p < 0.001), with a mean C:N ratio of 6.6. Digestate ammonia levels remained low (< 60 mg l−1) and below inhibitory thresholds during the collection period, but the ratio of NH3-N to total N increased from 0.09 in the food waste to 0.25 in the digestate. Digestate C and N content did not differ between digester models, while different pH (p < 0.05) was observed with a final pH of 6.1 in the commercial small-scale digester and a pH of 5.3 in the custom-built prototype. A survey of participating households revealed that 64% of respondents gained a new awareness of the volume of food waste they generated, and 87% expressed a willingness to recommend biodigesters despite challenges related to convenience and using this technology in a cold climate. Participants perceived the custom-built digester as more user-friendly than the commercial one. This case study highlights the potential of household-scale AD systems to generate biofertilizer, emphasizing the importance of user-friendliness and design tailored to household needs, generated feedstock, and environmental conditions

    Registration of ‘NS presser CLP’ hard red spring wheat

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    ‘NS Presser CLP’ (Reg. No. CV-1132, PI 679964) hard red spring wheat (Triticum aestivum L.) was developed by the Montana Agricultural Experiment Station and released in 2016 to the commercial partner Northern Seed LLC. NS Presser CLP is a two-gene Clearfield wheat intended for use with the selective imidazolinone herbicide imazamox (Beyond, BASF Corp.). NS Presser CLP was developed by a single backcross of alleles for resistance to the imidazolinone herbicide class into the recurrent parent ‘Vida’. Vida has been the most widely grown hard red spring wheat cultivar in Montana since 2010. Alleles for herbicide resistance at TaAHAS1D and TaAHAS1B were selected during the backcrossing process and line derivation using polymerase chain reaction markers developed by BASF. Three years of replicated yield trials at a total of 23 sites showed that NS Presser CLP has yield potential under dryland production similar to Vida. NS Presser CLP showed tolerance to a 2× rate of imidazolinone herbicide (87.6 g a.i. ha-1) applied at three testing sites in each of 2 yr. It provides a high-yielding Clearfield cultivar for dryland production in Montana and surrounding areas

    Comprehensive behavioral testing in the R6/2 mouse model of Huntington's disease shows no benefit from CoQ10 or minocycline

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    Previous studies of the effects of coenzyme Q10 and minocycline on mouse models of Huntington's disease have produced conflicting results regarding their efficacy in behavioral tests. Using our recently published best practices for husbandry and testing for mouse models of Huntington's disease, we report that neither coenzyme Q10 nor minocycline had significant beneficial effects on measures of motor function, general health (open field, rotarod, grip strength, rearing-climbing, body weight and survival) in the R6/2 mouse model. The higher doses of minocycline, on the contrary, reduced survival. We were thus unable to confirm the previously reported benefits for these two drugs, and we discuss potential reasons for these discrepancies, such as the effects of husbandry and nutrition
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