250 research outputs found

    Alternative Systems of Inquiry for a Sustainable Agriculture

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    Summary Scientific investigation has long been dominated by positivism, which holds that an independent reality driven by immutable laws exists. Consequently, it should be possible to define sustainability in absolute terms. Advances in alternative paradigms, however, suggest: that any attempt precisely to define sustainability is flawed; that problems are always open to interpretation; that the resolution of one problem inevitably leads to the production of another ‘problem?situation’, as problems are endemic; that the key feature now becomes the capacity of actors continually to learn about these changing conditions, so that they can act rapidly to transform existing activities; and that systems of learning and inquiry are needed to seek the multiple perspectives of the various stakeholders and encourage wider involvement and action. These systems of inquiry are participatory in nature, and the information and action arising from them is judged by a framework of trustworthiness criteria. Resumé Les systèmes de renseignement alternatifs pour l'agriculture durable Depuis longtemps, l'enquête scientifique se trouve dominée par le positivisme, qui maintient l'existence d'une réalité indépendante mue par des lois ellesmêmes immuables. Par conséquent, il devrait être possible de définir la durabilité dans des termes absolus. Toutefois, les progrès au niveau des paradigmes alternatifs auraient tendance à suggérer, d'abord, que toute tentative de définir la durabilité de manière précise est à priori fausse; ensuite, que tout problème est capable d'interprétations différentes; que la solution d'un problème mène inéluctablement à la production de situations problématiques, étant donné que les problèmes sont endémiques; que le facteur primordial est désormais, la capacité des acteurs à apprendre continûment quelles sont ces situations changeantes, de sorte qu'ils puissent agir rapidement pour transformer les activités existantes; et que la mise en place de systèmes d'enquête et d'acquisition des connaissances sont nécessaires afin que l'on puisse interroger les nombreuses perspectives des divers participants et par là, encourager une participation plus grande et plus active. Ces systèmes d'enquète sont intrinsèquement participatoires, aussi l'information et l'action qui en découlent doiventelles être jugées dans le cadre d'un ensemble de critères de fiabilité. Resumen Sistemas alternativos de investigación para una agricultura sostenible La investigación científica ha sido dominada durante mucho tiempo por el positivismo, que mantiene la existencia de una realidad independiente manejada por leyes inmutables. Consecuentemente, debe ser posible definir el mantenimiento en términos absolutos. Sin embargo, el avance de paradigmas alternativos sugiere: a) cualquier intento de definir la sostenibilidad con precisión es defectuoso; b) los problemas siempre están abiertos a la interpretación; c) la solución de un problema inevitablemente lleva a la producción de otra situación problemática, ya que los problemas son endémicos; d) el rasgo clave es la capacidad de los protagonistas para aprender continuamente de estas condiciónes cambiantes, y poder actuar rápidamente en la transformación de las actividades existentes; y e) se necesitan sistemas de averiguación y aprendizaje para registrar las múltiples perspectivas de las varias partes interesadas y estimular un compromiso y una acción mas emplios. Estos sistemas de averiguación son de por sí participatorios, y la información y acción que de ellos surgen son juzgadas por un conjunto de criterios de fiabilidad

    The challenges faced in the design, conduct and analysis of surgical randomised controlled trials

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    Randomised evaluations of surgical interventions are rare; some interventions have been widely adopted without rigorous evaluation. Unlike other medical areas, the randomised controlled trial (RCT) design has not become the default study design for the evaluation of surgical interventions. Surgical trials are difficult to successfully undertake and pose particular practical and methodological challenges. However, RCTs have played a role in the assessment of surgical innovations and there is scope and need for greater use. This article will consider the design, conduct and analysis of an RCT of a surgical intervention. The issues will be reviewed under three headings: the timing of the evaluation, defining the research question and trial design issues. Recommendations on the conduct of future surgical RCTs are made. Collaboration between research and surgical communities is needed to address the distinct issues raised by the assessmentof surgical interventions and enable the conduct of appropriate and well-designed trials.The Health Services Research Unit is funded by the Scottish Government Health DirectoratesPeer reviewedPublisher PD

    Treatment-Resistant Schizophrenia: Treatment Response and Resistance in Psychosis (TRRIP) Working Group Consensus Guidelines on Diagnosis and Terminology

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    OBJECTIVE: Research and clinical translation in schizophrenia is limited by inconsistent definitions of treatment resistance and response. To address this issue, the authors evaluated current approaches and then developed consensus criteria and guidelines. METHODS: A systematic review of randomized antipsychotic clinical trials in treatment-resistant schizophrenia was performed, and definitions of treatment resistance were extracted. Subsequently, consensus operationalized criteria were developed through 1) a multiphase, mixed methods approach, 2) identification of key criteria via an online survey, and 3) meetings to achieve consensus. RESULTS: Of 2,808 studies identified, 42 met inclusion criteria. Of these, 21 studies (50%) did not provide operationalized criteria. In the remaining studies, criteria varied considerably, particularly regarding symptom severity, prior treatment duration, and antipsychotic dosage thresholds; only two studies (5%) utilized the same criteria. The consensus group identified minimum and optimal criteria, employing the following principles: 1) current symptoms of a minimum duration and severity determined by a standardized rating scale; 2) moderate or worse functional impairment; 3) prior treatment consisting of at least two different antipsychotic trials, each for a minimum duration and dosage; 4) systematic monitoring of adherence and meeting of minimum adherence criteria; 5) ideally at least one prospective treatment trial; and 6) criteria that clearly separate responsive from treatment-resistant patients. CONCLUSIONS: There is considerable variation in current approaches to defining treatment resistance in schizophrenia. The authors present consensus guidelines that operationalize criteria for determining and reporting treatment resistance, adequate treatment, and treatment response, providing a benchmark for research and clinical translation

    Measuring Reciprocity in High Functioning Children and Adolescents with Autism Spectrum Disorders

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    Few instruments have been developed that measure impairments in reciprocity, a defining feature of autism. We introduce a new test assessing the quality of reciprocal behaviour: the interactive drawing test (IDT). Children and adolescents (n = 49) with and without high functioning autism spectrum disorders (HFASD) were invited to collaborate with an experimenter in making a joint drawing. Within both groups the performance on collaborative reciprocity improved with age. However, compared to the control group, HFASD participants showed less collaborative and more basic reciprocal behaviour and preferred to draw their own objects. They were less tolerant of the experimenter’s input as well. Performance on the IDT was independent of estimated verbal IQ. Reciprocal behaviour in self-initiated objects corresponded with more parental reported autistic traits, while reciprocal behaviour in other-initiated objects corresponded with less autistic traits. The findings of this study suggest that IDT is a promising instrument to assess reciprocity

    How accurate is an LCD screen version of the Pelli–Robson test?

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    Purpose: To evaluate the accuracy and repeatability of a computer-generated Pelli–Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli–Robson chart. Methods: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli–Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. Results: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli–Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland–Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli–Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland–Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. Conclusions: Computer-generated versions of Pelli–Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli–Robson printed version. Clinicians should consider that Pelli–Robson computer-generated versions could be non-interchangeable to the printed version

    Evidence for electron Landau damping in space plasma turbulence

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    How turbulent energy is dissipated in weakly collisional space and astrophysical plasmas is a major open question. Here, we present the application of a field-particle correlation technique to directly measure the transfer of energy between the turbulent electromagnetic field and electrons in the Earth's magnetosheath, the region of solar wind downstream of the Earth's bow shock. The measurement of the secular energy transfer from the parallel electric field as a function of electron velocity shows a signature consistent with Landau damping. This signature is coherent over time, close to the predicted resonant velocity, similar to that seen in kinetic Alfven turbulence simulations, and disappears under phase randomisation. This suggests that electron Landau damping could play a significant role in turbulent plasma heating, and that the technique is a valuable tool for determining the particle energisation processes operating in space and astrophysical plasmas.STFC Ernest Rutherford Fellowship [ST/N003748/2]; NASA HSR grant [NNX16AM23G]; NSF CAREER Award [AGS-1054061]; NASA HGI grant [80NSSC18K0643]; NASA MMS GI grant [80NSSC18K1371]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    The genomic basis of adaptive evolution in threespine sticklebacks

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    Marine stickleback fish have colonized and adapted to thousands of streams and lakes formed since the last ice age, providing an exceptional opportunity to characterize genomic mechanisms underlying repeated ecological adaptation in nature. Here we develop a high-quality reference genome assembly for threespine sticklebacks. By sequencing the genomes of twenty additional individuals from a global set of marine and freshwater populations, we identify a genome-wide set of loci that are consistently associated with marine–freshwater divergence. Our results indicate that reuse of globally shared standing genetic variation, including chromosomal inversions, has an important role in repeated evolution of distinct marine and freshwater sticklebacks, and in the maintenance of divergent ecotypes during early stages of reproductive isolation. Both coding and regulatory changes occur in the set of loci underlying marine–freshwater evolution, but regulatory changes appear to predominate in this well known example of repeated adaptive evolution in nature.National Human Genome Research Institute (U.S.)National Human Genome Research Institute (U.S.) (NHGRI CEGS Grant P50-HG002568
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