289 research outputs found

    Abundance, movements and biodiversity of flying predatory insects in crop and non-crop agroecosystems

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    [EN] Predatory insects are key natural enemies that can highly reduce crops pest damage. However, there is a lack of knowledge about the movements of flying predatory insects in agroecosystems throughout the year. In particular, it is still unclear how these predators move from crop to non-crop habitats, which are the preferred habitats to overwinter and to spread during the spring and if these predators leave or stay after chemical treatments. Here, the Neuroptera, a generalist, highly mobile, flying predator order of insects, was selected as model. We studied the effects of farming management and the efficiency of edge shelterbelts, ground cover vegetation, and fruit trees canopy on holding flying predatory insects in Mediterranean traditional agroecosystems. Seasonal movements and winter effects were also assessed. We evaluated monthly nine fruit agroecosystems, six organic, and three pesticides sprayed, of 0.5-1 ha in eastern Spain during 3 years using two complementary methods, yellow sticky traps and aspirator. Results show surprisingly that the insect abundance was highest in pesticide sprayed systems, with 3.40 insects/sample versus 2.32 insects/sample in organic systems. The biodiversity indices were highest in agroecosystems conducted under organic management, with S of 4.68 and D of 2.34. Shelterbelts showed highest biodiversity indices, S of 3.27 and D of 1.93, among insect habitats. Insect species whose adults were active during the winter preferred fruit trees to spend all year round. However, numerous species moved from fruit trees to shelterbelts to overwinter and dispersed into the orchard during the following spring. The ground cover vegetation showed statistically much lower attractiveness for flying predatory insects than other habitats. Shelterbelts should therefore be the first option in terms of investment in ecological infrastructures enhancing flying predators.Sorribas Mellado, JJ.; González Cavero, S.; Domínguez Gento, A.; Vercher Aznar, R. (2016). Abundance, movements and biodiversity of flying predatory insects in crop and non-crop agroecosystems. Agronomy for Sustainable Development. 36(2). doi:10.1007/s13593-016-0360-3S362Altieri MA, Letourneau DK (1982) Vegetation management and biological control in agroecosystems. Crop Prot 1:405–430. doi: 10.1016/0261-2194(82)90023-0Altieri MA, Schmidt LL (1986) The dynamics of colonizing arthropod communities at the interface of abandoned, organic and commercial apple orchards and adjacent woodland habitats. Agric Ecosyst Environ 16:29–43. doi: 10.1016/0167-8809(86)90073-3Bengtsson J, Ahnström J, Weibull A (2005) The effects of organic agriculture on biodiversity and abundance: a meta-analysis. 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J Appl Ecol 52:270–279. doi: 10.1111/1365-2664.12363Pollard KA, Holland JM (2006) Arthropods within the woody element of hedgerows and their distribution pattern. Agric Forest Entomol 8:203–211. doi: 10.1111/j.1461-9563.2006.00297.xRand TA, Tylianakis JM, Tscharntke T (2006) Spillover edge effects: the dispersal of agriculturally subsidized insect natural enemies into adjacent natural habitats. Ecol Lett 9:603–614. doi: 10.1111/j.1461-0248.2006.00911.xSilva EB, Franco JC, Vasconcelos T, Branco M (2010) Effect of ground cover vegetation on the abundance and diversity of beneficial arthropods in citrus orchards. Bull Entomol Res 100:489–499. doi: 10.1017/S0007485309990526Smukler SM, Sánchez-Moreno S et al (2010) Biodiversity and multiple ecosystem functions in an organic farmscape. Agric Ecosyst Environ 139:80–97. doi: 10.1016/j.agee.2010.07.004Stelzl M, Devetak D (1999) Neuroptera in agricultural ecosystems. 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    Impact Factor: outdated artefact or stepping-stone to journal certification?

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    A review of Garfield's journal impact factor and its specific implementation as the Thomson Reuters Impact Factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.Comment: 25 pages, 12 figures, 6 table

    Age differences in physiological responses to self-paced and incremental V˙O2max\dot V O_{2max} testing

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    Purpose: A self-paced maximal exercise protocol has demonstrated higher V˙O2max\dot V O_{2max} values when compared against traditional tests. The aim was to compare physiological responses to this self-paced V˙O2max\dot V O_{2max} protocol (SPV) in comparison to a traditional ramp V˙O2max\dot V O_{2max} (RAMP) protocol in young (18–30 years) and old (50–75 years) participants. Methods: Forty-four participants (22 young; 22 old) completed both protocols in a randomised, counter-balanced, crossover design. The SPV included 5 × 2 min stages, participants were able to self-regulate their power output (PO) by using incremental ‘clamps’ in ratings of perceived exertion. The RAMP consisted of either 15 or 20 W min1^{−1}. Results: Expired gases, cardiac output (Q), stroke volume (SV), muscular deoxyhaemoglobin (deoxyHb) and electromyography (EMG) at the vastus lateralis were recorded throughout. Results demonstrated significantly higher V˙O2max\dot V O_{2max} in the SPV (49.68 ± 10.26 ml kg1^{−1} min1^{−1}) vs. the RAMP (47.70 ± 9.98 ml kg1^{−1} min1^{−1}) in the young, but not in the old group (>0.05). Q and SV were significantly higher in the SPV vs. the RAMP in the young (0.05). No differences seen in deoxyHb and EMG for either age groups (>0.05). Peak PO was significantly higher in the SPV vs. the RAMP in both age groups (<0.05). Conclusion: Findings demonstrate that the SPV produces higher V˙O2max\dot V O_{2max}, peak Q and SV values in the young group. However, older participants achieved similar V˙O2max\dot V O_{2max} values in both protocols, mostly likely due to age-related differences in cardiovascular responses to incremental exercise, despite them achieving a higher physiological workload in the SPV

    Self-assembled amyloid fibrils with controllable conformational heterogeneity

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    Amyloid fibrils are a hallmark of neurodegenerative diseases and exhibit a conformational diversity that governs their pathological functions. Despite recent findings concerning the pathological role of their conformational diversity, the way in which the heterogeneous conformations of amyloid fibrils can be formed has remained elusive. Here, we show that microwave-assisted chemistry affects the self-assembly process of amyloid fibril formation, which results in their conformational heterogeneity. In particular, microwave-assisted chemistry allows for delicate control of the thermodynamics of the self-assembly process, which enabled us to tune the molecular structure of ??-lactoglobulin amyloid fibrils. The heterogeneous conformations of amyloid fibrils, which can be tuned with microwave-assisted chemistry, are attributed to the microwave-driven thermal energy affecting the electrostatic interaction during the self-assembly process. Our study demonstrates how microwave-assisted chemistry can be used to gain insight into the origin of conformational heterogeneity of amyloid fibrils as well as the design principles showing how the molecular structures of amyloid fibrils can be controlledopen0

    Mitral Cells of the Olfactory Bulb Perform Metabolic Sensing and Are Disrupted by Obesity at the Level of the Kv1.3 Ion Channel

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    Sixty-five percent of Americans are over-weight. While the neuroendocrine controls of energy homeostasis are well known, how sensory systems respond to and are impacted by obesity is scantily understood. The main accepted function of the olfactory system is to provide an internal depiction of our external chemical environment, starting from the detection of chemosensory cues. We hypothesized that the system additionally functions to encode internal chemistry via the detection of chemicals that are important indicators of metabolic state. We here uncovered that the olfactory bulb (OB) subserves as an internal sensor of metabolism via insulin-induced modulation of the potassium channel Kv1.3. Using an adult slice preparation of the olfactory bulb, we found that evoked neural activity in Kv1.3-expressing mitral cells is enhanced following acute insulin application. Insulin mediated changes in mitral cell excitability are predominantly due to the modulation of Kv1.3 channels as evidenced by the lack of effect in slices from Kv1.3-null mice. Moreover, a selective Kv1.3 peptide blocker (ShK186) inhibits more than 80% of the outward current in parallel voltage-clamp studies, whereby insulin significantly decreases the peak current magnitude without altering the kinetics of inactivation or deactivation. Mice that were chronically administered insulin using intranasal delivery approaches exhibited either an elevation in basal firing frequency or fired a single cluster of action potentials. Following chronic administration of the hormone, mitral cells were inhibited by application of acute insulin rather than excited. Mice made obese through a diet of ∼32% fat exhibited prominent changes in mitral cell action potential shape and clustering behavior, whereby the subsequent response to acute insulin stimulation was either attenuated or completely absent. Our results implicate an inappropriate neural function of olfactory sensors following exposure to chronic levels of the hormone insulin (diabetes) or increased body weight (obesity)

    Role and Mechanism of Arsenic in Regulating Angiogenesis

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    Arsenic is a wide spread carcinogen associated with several kinds of cancers including skin, lung, bladder, and liver cancers. Lung is one of the major targets of arsenic exposure. Angiogenesis is the pivotal process during carcinogenesis and chronic pulmonary diseases, but the role and mechanism of arsenic in regulating angiogenesis remain to be elucidated. In this study we show that short time exposure of arsenic induces angiogenesis in both human immortalized lung epithelial cells BEAS-2B and adenocarcinoma cells A549. To study the molecular mechanism of arsenic-inducing angiogenesis, we find that arsenic induces reactive oxygen species (ROS) generation, which activates AKT and ERK1/2 signaling pathways and increases the expression of hypoxia-inducible factor 1 (HIF-1) and vascular endothelial growth factor (VEGF). Inhibition of ROS production suppresses angiogenesis by decreasing AKT and ERK activation and HIF-1 expression. Inhibition of ROS, AKT and ERK1/2 signaling pathways is sufficient to attenuate arsenic-inducing angiogenesis. HIF-1 and VEGF are downstream effectors of AKT and ERK1/2 that are required for arsenic-inducing angiogenesis. These results shed light on the mechanism of arsenic in regulating angiogenesis, and are helpful to develop mechanism-based intervention to prevent arsenic-induced carcinogenesis and angiogenesis in the future

    Characterization of collective ground states in single-layer NbSe2

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    Layered transition metal dichalcogenides (TMDs) are ideal systems for exploring the effects of dimensionality on correlated electronic phases such as charge density wave (CDW) order and superconductivity. In bulk NbSe2 a CDW sets in at TCDW = 33 K and superconductivity sets in at Tc = 7.2 K. Below Tc these electronic states coexist but their microscopic formation mechanisms remain controversial. Here we present an electronic characterization study of a single 2D layer of NbSe2 by means of low temperature scanning tunneling microscopy/spectroscopy (STM/STS), angle-resolved photoemission spectroscopy (ARPES), and electrical transport measurements. We demonstrate that 3x3 CDW order in NbSe2 remains intact in 2D. Superconductivity also still remains in the 2D limit, but its onset temperature is depressed to 1.9 K. Our STS measurements at 5 K reveal a CDW gap of {\Delta} = 4 meV at the Fermi energy, which is accessible via STS due to the removal of bands crossing the Fermi level for a single layer. Our observations are consistent with the simplified (compared to bulk) electronic structure of single-layer NbSe2, thus providing new insight into CDW formation and superconductivity in this model strongly-correlated system.Comment: Nature Physics (2015), DOI:10.1038/nphys352

    Adventurous Physical Activity Environments: A Mainstream Intervention for Mental Health

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    Adventurous physical activity has traditionally been considered the pastime of a small minority of people with deviant personalities or characteristics that compel them to voluntarily take great risks purely for the sake of thrills and excitement. An unintended consequence of these traditional narratives is the relative absence of adventure activities in mainstream health and well-being discourses and in large-scale governmental health initiatives. However, recent research has demonstrated that even the most extreme adventurous physical activities are linked to enhanced psychological health and well-being outcomes. These benefits go beyond traditional ‘character building’ concepts and emphasize more positive frameworks that rely on the development of effective environmental design. Based on emerging research, this paper demonstrates why adventurous physical activity should be considered a mainstream intervention for positive mental health. Furthermore, the authors argue that understanding how to design environments that effectively encourage appropriate adventure should be considered a serious addition to mainstream health and well-being discourse

    Properties that influence business process management maturity and its effect on organizational performance

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    Abstract BPM maturity is a measure to evaluate how professionally an organization manages its business processes. Previous research provides evidence that higher BPM maturity leads to better performance of processes and of the organization as a whole. It also claims that different organizations should strive for different levels of maturity, depending on their properties. This paper presents an empirical investigation of these claims, based on a sample of 120 organizations and looking at a selection of organizational properties. Our results reveal that higher BPM maturity contributes to better performance, but only up to a point. Interestingly, it contradicts the popular belief that higher innovativeness is associated with lower BPM maturity, rather showing that higher innovativeness is associated with higher BPM maturity. In addition, the paper shows that companies in different regions have a different level of BPM maturity. These findings can be used as a benchmark and a motivation for organizations to increase their BPM maturity
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