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There is increasing evidence that farmers in many areas are achieving below maximum yields due to insufficient pollination. Practical and effective approaches are needed to maintain wild pollinator populations within agroecosystems so they can deliver critical pollination services that underpin crop production. We established nesting and wildflower habitat interventions in 24 UK apple orchards and measured effects on flower-visiting insects and the pollination they provide, exploring how this was affected by landscape context. We quantified the extent of pollination deficits and assessed whether the management of wild pollinators can reduce deficits and deliver improved outcomes for growers over 3 years. Wildflower interventions increased solitary bee numbers visiting apple flowers by over 20%, but there was no effect of nesting interventions. Other pollinator groups were influenced by both local and landscape-scale factors, with bumblebees and hoverflies responding to the relative proportion of semi-natural habitat at larger spatial scales (1000 m), while honeybees and other flies responded at 500 m or less. By improving fruit number and quality, pollinators contributed more than £16 k per hectare. However, deficits (where maximum potential was not being reached due to a lack of pollination) were recorded and the extent of these varied across orchards, and from year to year, with a 22% deficit in output in the worst (equivalent to ~£14 k/ha) compared to less than 3% (equivalent to ~£2 k/ha) in the best year. Although no direct effect of our habitat interventions on deficits in gross output was observed, initial fruit set and seed set deficits were reduced by abundant bumblebees, and orchards with a greater abundance of solitary bees saw lower deficits in fruit size. The abundance of pollinators in apple orchards is influenced by different local and landscape factors that interact and vary between years. Consequently, pollination, and the extent of economic output deficits, also vary between orchards and years. We highlight how approaches, including establishing wildflower areas and optimizing the ratio of cropped and non-cropped habitats can increase the abundance of key apple pollinators and improve outcomes for growers.
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Malus , Polinização , Abelhas , Animais , Ecossistema , Insetos , Frutas , Produtos Agrícolas , FloresRESUMO
The effective and safe detection of illicit materials, explosives in particular, is currently of growing importance taking into account the geopolitical situation and increasing risk of a terrorist attack. The commonly used methods of detection are based predominantly on metal detectors and georadars, which show only the shapes of the possible dangerous objects and do not allow for exact identification and risk assessment. A supplementary or even alternative method may be based on neutron activation analysis, which provides the possibility of a stoichiometric analysis of the suspected object and its non-invasive identification. One such sensor is developed by the SABAT collaboration, with its primary application being underwater threat detection. In this article, we present performance studies of this sensor, integrated with a mobile robot, in terms of the minimal detectable quantity of commonly used explosives in different environmental conditions. The paper describes the functionality of the used platform considering electronics, sensors, onboard computing power, and communication system to carry out manual operation and remote control. Robotics solutions based on modularized structures allow the extension of sensors and effectors that can significantly improve the safety of personnel as well as work efficiency, productivity, and flexibility.
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Substâncias Explosivas , Robótica , Simulação por Computador , Eletrônica , NêutronsRESUMO
In view of a result recently published in the context of the deformation theory of linear Hamiltonian systems, we reconsider the eigenvalue problem associated with the angular equation arising after the separation of the Dirac equation in the Kerr metric, and we show how a quasilinear first order PDE for the angular eigenvalues can be derived efficiently. We also prove that it is not possible to obtain an ordinary differential equation for the eigenvalues when the role of the independent variable is played by the particle energy or the black hole mass. Finally, we construct new perturbative expansions for the eigenvalues in the Kerr case and obtain an asymptotic formula for the eigenvalues in the case of a Kerr naked singularity.
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We reconsider the case of the geodesic motion of a massive and massless beam of test particles in a gravitational wave. In particular, we use a direct Lagrangian approach which simplifies the calculation. Our findings differ partly from previously performed calculations The final result can be interpreted as rings of light seen by the observer. We give a new interpretation to this picture and show that over large distances the effect, albeit rare, could in principle be observable.
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Sown wildflower areas are increasingly recommended as an agri-environmental intervention measure, but evidence for their success is limited to particular insect groups or hampered by the challenges of establishing seed mixes and maintaining flower abundance over time. We conducted a replicated experiment to establish wildflower areas to support insect pollinators in apple orchards. Over three years, and across 23 commercial UK orchards with and without sown wildflowers, we conducted 828 transect surveys across various non-crop habitats. We found that the abundance of flower-visiting solitary bees, bumblebees, honeybees, and beetles was increased in sown wildflower areas, compared with existing non-crop habitats in control orchards, from the second year following floral establishment. Abundance of hoverflies and other non-syrphid flies was increased in wildflower areas from the first year. Beyond the effect of wildflower areas, solitary bee abundance was also positively related to levels of floral cover in other local habitats within orchards, but neither local nor wider landscape-scale context affected abundance of other studied insect taxa within study orchards. There was a change in plant community composition on the sown wildflower areas between years, and in patterns of flowering within and between years, showing a succession from unsown weedy species towards a dominance of sown species over time. We discuss how the successful establishment of sown wildflower areas and delivery of benefits for different insect taxa relies on appropriate and reactive management practices as a key component of any such agri-environment scheme.
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OBJECTIVES: To assess the skeletal status in asthmatic children treated with inhaled corticosteroids in a longitudinal observation by quantitative ultrasound (US) measurement at the hand phalanges. METHODS: Thirty-four children were studied prospectively. Quantitative US measurements were performed at baseline and after a mean ± SD of 2.35 ± 0.20 years. The obtained results were compared to age-, sex-, and body size-matched control participants selected from a database of previously examined healthy children. Individual changes in the amplitude-dependent speed of sound (Ad-SoS) during the follow-up period were also analyzed. RESULTS: The mean age of the asthmatic children was 10.6 ± 2.5 years. The mean Ad-SoS in the asthmatic children at baseline was 1940.5 ± 49.6 m/s, and the mean Z score was -0.26 ± 0.80. Corresponding values at the follow-up examination were 1976.2 ± 63.6 m/s and -0.18 ± 1.16. The results did not differ significantly in comparison to the healthy controls. The analysis of individual changes in Ad-SoS revealed that 18 participants had a significant increase in this parameter (ie, exceeding the least significant change threshold), and 16 did not have a significant change in their values. No one had a significant decrease in Ad-SoS. CONCLUSIONS: Quantitative US at the hand phalanges applied as a diagnostic tool revealed no essential differences in the pattern of skeletal development between asthmatic children treated with inhaled glucocorticosteroids and healthy controls.
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Corticosteroides/uso terapêutico , Asma/tratamento farmacológico , Falanges dos Dedos da Mão/anatomia & histologia , Ultrassonografia/métodos , Administração por Inalação , Adolescente , Adulto , Criança , Estudos de Avaliação como Assunto , Feminino , Falanges dos Dedos da Mão/efeitos dos fármacos , Seguimentos , Humanos , Estudos Longitudinais , Masculino , Estudos Prospectivos , Adulto JovemRESUMO
Ecological intensification has been promoted as a means to achieve environmentally sustainable increases in crop yields by enhancing ecosystem functions that regulate and support production. There is, however, little direct evidence of yield benefits from ecological intensification on commercial farms growing globally important foodstuffs (grains, oilseeds and pulses). We replicated two treatments removing 3 or 8% of land at the field edge from production to create wildlife habitat in 50-60 ha patches over a 900 ha commercial arable farm in central England, and compared these to a business as usual control (no land removed). In the control fields, crop yields were reduced by as much as 38% at the field edge. Habitat creation in these lower yielding areas led to increased yield in the cropped areas of the fields, and this positive effect became more pronounced over 6 years. As a consequence, yields at the field scale were maintained--and, indeed, enhanced for some crops--despite the loss of cropland for habitat creation. These results suggested that over a 5-year crop rotation, there would be no adverse impact on overall yield in terms of monetary value or nutritional energy. This study provides a clear demonstration that wildlife-friendly management which supports ecosystem services is compatible with, and can even increase, crop yields.
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Agricultura/métodos , Animais Selvagens/fisiologia , Biodiversidade , Conservação dos Recursos Naturais , Produtos Agrícolas/crescimento & desenvolvimento , Animais , InglaterraRESUMO
Agricultural intensification is a leading cause of global biodiversity loss, especially for threatened and near-threatened species. One widely implemented response is 'wildlife-friendly farming', involving the close integration of conservation and extensive farming practices within agricultural landscapes. However, the putative benefits from this controversial policy are currently either unknown or thought unlikely to extend to rare and declining species. Here, we show that new, evidence-based approaches to habitat creation on intensively managed farmland in England can achieve large increases in plant, bee and bird species. In particular, we found that habitat enhancement methods designed to provide the requirements of sensitive target biota consistently increased the richness and abundance of both rare and common species, with 10-fold to greater than 100-fold more rare species per sample area than generalized conventional conservation measures. Furthermore, targeting landscapes of high species richness amplified beneficial effects on the least mobile taxa: plants and bees. Our results provide the first unequivocal support for a national wildlife-friendly farming policy and suggest that this approach should be implemented much more extensively to address global biodiversity loss. However, to be effective, these conservation measures must be evidence-based, and developed using sound knowledge of the ecological requirements of key species.
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Abelhas/fisiologia , Aves/fisiologia , Fenômenos Fisiológicos Vegetais , Agricultura/métodos , Animais , Biodiversidade , Conservação dos Recursos Naturais/métodos , Produtos Agrícolas/metabolismo , Ecologia/métodos , Ecossistema , Meio Ambiente , Plantas/metabolismo , Distribuição de Poisson , Especificidade da EspécieRESUMO
The aim of the study was to assess the skeletal status by quantitative ultrasound measurement at hand phalanges in asthmatic children treated with inhaled corticosteroids. Sixty-nine (69) children with a mean age of 10.9 ± 2.6 y and 251 controls matched for age and body size were enrolled into the study. The mean value of amplitude-dependent speed of sound in asthmatic children was 1953.8 ± 60.2 m/s and the mean Z-score was -0.05 ± 1.02; the corresponding values in the controls were 1951.0 ± 53.9 m/s and -0.26 ± 1.05, respectively. The results did not differ between the asthmatic and the healthy (control) children. A cumulative dose of inhaled steroids was identified in a stepwise regression analysis as a factor with potentially negative influence on bone status. In conclusion, the skeletal status in asthmatic children, assessed by quantitative ultrasound, shows no difference in comparison with healthy children. Nonetheless, special caution is necessary in case of long-term corticosteroid therapy, in which a slightly negative influence of treatment on the skeleton cannot be excluded.
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Determinação da Idade pelo Esqueleto , Asma/tratamento farmacológico , Falanges dos Dedos da Mão/diagnóstico por imagem , Glucocorticoides/administração & dosagem , Administração por Inalação , Tamanho Corporal , Estudos de Casos e Controles , Criança , Feminino , Humanos , Masculino , Projetos Piloto , Análise de Regressão , Estatísticas não Paramétricas , UltrassonografiaRESUMO
UNLABELLED: The presence of chronic disease is a risk factor for the development of mood disturbances and panic disorders. They can influence the course of disease and effectiveness of therapy. Depression may be the cause of making light doctor's advice. Anxious patients often aggravate symptoms of the disease. AIM: To study symptoms of anxiety and depression in patients suffering from atopic eczema/dermatitis syndrome (ZAZS). Material. We studied 38 patients suffering from adequately controlled moderate ZAZS and 62 volunteers in the control group. METHODS: Mental status of subjects was assessed by means of State and Trait Anxiety Inventory (STAI) and Beck Depression Inventory (BDI) questionnaires. RESULTS: ZAZS patients demonstrated higher intensity of anxiety (as a trait and as a state) than healthy subjects. Intensity and prevalence of depression in the atopic eczema/ dermatitis syndrome group was higher than in the control group. CONCLUSIONS: Patients suffering from atopic/eczema dermatitis syndrome are pre-disposed to anxiety and depression manifestation. Even adequately controlled symptoms of atopic/eczema dermatitis syndrome may be the cause of those disturbances' occurrence.
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Adaptação Psicológica , Ansiedade/etiologia , Depressão/etiologia , Dermatite Atópica/psicologia , Qualidade de Vida , Adulto , Estudos de Casos e Controles , Dermatite Atópica/terapia , Feminino , Nível de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Índice de Gravidade de Doença , Estresse Psicológico/etiologia , Inquéritos e QuestionáriosRESUMO
Blood platelet significance in inflammation is recognized but poorly characterized in urticaria. It is known that platelets are activated during inflammatory processes and are involved in modulating inflammatory and immune response via various mediator release. The aim of our study was to investigate the functional state of platelets, expressed by release reaction of C-X-C chemokines such as platelet factor 4 (PF-4) and beta-thromboglobulin (beta-TG) in chronic idiopathic urticaria (CIU). Plasma levels of PF-4 and beta-TG, which are established markers of in vivo platelet activation and which play important role in inflammatory processes, were measured by enzyme-linked immunosorbent assay in 19 patients with CIU and in 25 healthy subjects. Mean plasma PF-4 level in CIU patients and control subjects was 5.01 +/- 1.67 and 4.13 +/- 2.05 IU/ml, respectively, whereas that for beta-TG was 29.3 +/- 14.0 and 25.2 +/- 12.6 IU/ml, respectively. In our small study, there have been no significant differences found between the members of the control and CIU group regarding plasma levels of PF-4 and beta-TG. Further studies should be performed to elucidate whether any systemic platelet activation occurs in CIU.
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Ativação Plaquetária , Fator Plaquetário 4/metabolismo , Urticária/sangue , beta-Tromboglobulina/metabolismo , Adolescente , Adulto , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Mediadores da Inflamação/sangue , Masculino , Urticária/imunologiaRESUMO
Data gathered prove that circulating platelets are activated upon human allergic inflammation, partly as a result of direct IgE-mediated process. It has been indicated that platelets may contribute to pathogenesis of atopic eczema/dermatitis syndrome (AEDS). Authors of the recent study have investigated systemic platelet activation in patients with AEDS on the basis of blood level of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4), which are recognized markers of platelet activation, also belonging to C-X-C chemokine family. Plasma levels of beta-TG and PF4 were measured by enzyme-linked immunoassay (ELISA) in 18 AEDS patients with moderate disease activity and 23 healthy, nonatopic individuals. No differences in peripheral platelet count of the two groups were noted. Only four (33.3%) AEDS patients represented beta-TG and PF4 within the control range; plasma beta-TG and PF4 were significantly increased (p < 0.001) in the AEDS group compared as a whole with the control subjects. No association between circulating concentrations of beta-TG or PF4 and total IgE levels in AEDS patients was proved. The results suggest that some patients with AEDS may have enhanced blood platelet activity as expressed by beta-TG and PF4 level.
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Dermatite Atópica/imunologia , Eczema/imunologia , Ativação Plaquetária , Adolescente , Adulto , Plaquetas/imunologia , Plaquetas/metabolismo , Dermatite Atópica/sangue , Dermatite Atópica/metabolismo , Eczema/sangue , Eczema/metabolismo , Feminino , Humanos , Imunoglobulina E/análise , Masculino , Ativação Plaquetária/imunologia , Fator Plaquetário 4/análise , Síndrome , beta-Tromboglobulina/análiseRESUMO
We discuss two applications of a Riccati equation to Newton's laws of motion. The first one is the motion of a particle under the influence of a power law central potential V(r)=kr(epsilon). For zero total energy we show that the equation of motion can be cast in the Riccati form. We briefly show here an analogy to barotropic Friedmann-Robertson-Lemaitre cosmology where the expansion of the universe can be also shown to obey a Riccati equation. A second application in classical mechanics, where again the Riccati equation appears naturally, are problems involving quadratic friction. We use methods reminiscent to nonrelativistic supersymmetry to generalize and solve such problems.
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The purpose of this study was an evaluation of the ability of the multiphase spiral CT and MR imaging to localise focal liver lesions referring to specific hepatic segments. The authors studied prospectively 26 focal liver lesions in 26 patients who had undergone spiral CT and MRI before surgery. Multiphase spiral CT included non-contrast scans, hepatic arterial-dominant phase, portal venous--dominant phase and equilibrium phase. MRI was performed in all cases. The following sequences were performed: SE and TSE T1- and T2-weighted images, STIR and dynamic T1-weighted FFE study after i.v. administration of gadolinium (Gd-DTPA). The CT and MR scans were prospectively and independently reviewed by three radiologists for visualisation of hepatic and portal veins and segmental localisation of hepatic lesions. The authors used the right and left main portal veins along with transverse fissura, hepatic veins and gallbladder fossa as landmarks for the tumour localisation to specific hepatic segments. The primary segmental locations of the lesions were correctly determined with CT in 22 of 26 focal liver lesions (85%) and with MR imaging in 24 of 26 lesions (92%). The full extent of lesions was correctly described with sCT in 19 of 26 focal lesions and with MR in 21 of 26 tumours. MRI and CT were helpful preoperative tools for determining the segmental location of focal liver lesions and for planning the surgical approach.