94 research outputs found

    Shade trees decrease pest abundances on brassica crops in Kenya

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    Agroforestry practices may mitigate the current loss of biodiversity and ecosystem services due to deforestation and agricultural intensification. To examine the effects of agroforestry on the ecosystem service of pest regulation, we assessed pest abundances and biological control potential in shaded and open kale (Brassica oleracea L. acephala) fields in Western Kenya. Specifically, we compared the abundance of pest aphids and caterpillars, ground-dwelling ants, spiders and predatory beetles, and examined aphid parasitism rates, predation rates on diamondback moth eggs, attack rates on surrogate caterpillars and bird predation on aphids. Shade trees effectively reduced abundances of aphids, caterpillars and increased abundances of spiders and predatory beetles, but neither affected ant abundances, or predation and parasitism rates. Our results suggest that presence of shade trees can decrease pest abundances, but that this is not only due to improved biological control by natural enemies but also due to microclimatic conditions affecting pest performance and bottom-up processes such as changes in plant quality and soil conditions. We encourage studies exploring simultaneously how top-down and bottom-up processes affect pest regulation in agroforestry settings

    A global horizon scan of the future impacts of robotics and autonomous systems on urban ecosystems

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    Technology is transforming societies worldwide. A significant innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionise cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the findings of an online horizon scan involving 170 expert participants from 35 countries. We conclude that RAS are likely to transform land-use, transport systems and human-nature interactions. The prioritised opportunities were primarily centred on the deployment of RAS for monitoring and management of biodiversity and ecosystems. Fewer challenges were prioritised.Those that were emphasised concerns surrounding waste from unrecovered RAS, and the quality and interpretation of RAS-collected data. Although the future impacts of RAS for urban ecosystems are hard to predict, examining potentially important developments early is essential if we are to avoid detrimental consequences, but fully realise the benefits

    Tissue engineering approaches for the repair and regeneration of the anterior cruciate ligament: towards 3D bioprinted ACL-on-chip.

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    The anterior cruciate ligament (ACL) is the most frequently injured ligament in the knee. The current method to treat the injured ligament is reconstruction using autografts and allografts. Reconstruction requires the regeneration of ligament, bone and their interface to ensure proper recovery. Recently, researchers have focused on using tissue-engineered scaffolds made of synthetic materials and biomaterials -such as collagen, decellularised tissues, silk and synthetic polymers produced following different manufacturing methods - for ACL reconstruction,. Different materials can be easily processed using various fabrication methods for mimicking the mechanical properties of the ACL. The advances in technologies play an important role in the production of constructions that can mimic native ACL.. The present review addresses integrative scaffold design, different challenges in the potential materials and manufacturing methods as well as future strategies for ACL repair. Furthermore, the review provides a road map to 3D printing combined with organ-on-chip technology to demonstrate the potential for cost-effective and user-friendly fabrication methods for ACL engineering. Finally, it underlines the potential of 3D bioprinting and organ-on-chip technologies for micro-engineering of ligaments and their associated environment

    A global meta-analysis reveals contrasting impacts of air, light, and noise pollution on pollination

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    In the face of biodiversity decline, understanding the impact of anthropogenic disturbances on ecosystem functions is critical for mitigation. Elevated levels of pollution are a major threat to biodiversity, yet there is no synthesis of their impact on many of the major ecosystem functions, including pollination. This ecosystem function is both particularly vulnerable as it depends on the fine-tuned interaction between plants and pollinators and hugely important as it underpins the flora of most habitats as well as food production. Here, we untangle the impact of air, light, and noise pollution on the pollination system by systematically evaluating and synthesizing the published evidence via a meta-analysis. We identified 58 peer-reviewed articles from three databases. Mixed-effects meta-regression models indicated that air pollution negatively impacts pollination. However, there was no effect of light pollution, despite previous studies that concentrated solely on pollinators suggesting a negative impact. Evidence for noise pollution was extremely limited. Unless action is taken to tackle air pollution, the capacity to support well-functioning diverse pollination systems will be compromised, with negative consequences for habitat conservation and food security

    Urban green infrastructure and ecosystem services in sub-Saharan Africa

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    Africa is urbanizing at an astonishing rate. To meet many of the Sustainable Development Goals there will be a requirement for cities in sub-Saharan Africa to plan for, and manage, the rapid rise in the urban population. Green infrastructure has the potential to provide multiple ecosystem services to benefit the urban population. The general objective of this review is to consolidate research undertaken on urban green infrastructure and the associated ecosystem services in sub-Saharan African cities. The 68 reviewed papers spanned 20 countries and included 74 urban areas. However, only 38% of sub-Saharan countries had any research carried out in them. The most represented ecosystem services were regulating and provisioning, with supporting services getting the least attention. Overall there was a lack of in-depth studies on all ecosystem services, especially supporting and cultural services. Seven overarching categories of barriers and challenges to the sustainable delivery of ecosystem services emerged from the reviewed papers, namely: (i) socio-cultural values, traditions and perceptions; (ii) lack of capacity; (iii) governance, urban planning and social inequality; (iv) lack of data and/or case studies; (v) ecosystem disservices; (vi) spatial trade-offs and conflicts; (vii) climate change. These barriers we identified will need to be addressed if the future, long-term sustainable provision of ecosystem services in sub-Saharan African cities is to be assured

    Empirical chemosensitivity testing in a spheroid model of ovarian cancer using a microfluidics-based multiplex platform.

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    The use of biomarkers to infer drug response in patients is being actively pursued, yet significant challenges with this approach, including the complicated interconnection of pathways, have limited its application. Direct empirical testing of tumor sensitivity would arguably provide a more reliable predictive value, although it has garnered little attention largely due to the technical difficulties associated with this approach. We hypothesize that the application of recently developed microtechnologies, coupled to more complex 3-dimensional cell cultures, could provide a model to address some of these issues. As a proof of concept, we developed a microfluidic device where spheroids of the serous epithelial ovarian cancer cell line TOV112D are entrapped and assayed for their chemoresponse to carboplatin and paclitaxel, two therapeutic agents routinely used for the treatment of ovarian cancer. In order to index the chemoresponse, we analyzed the spatiotemporal evolution of the mortality fraction, as judged by vital dyes and confocal microscopy, within spheroids subjected to different drug concentrations and treatment durations inside the microfluidic device. To reflect microenvironment effects, we tested the effect of exogenous extracellular matrix and serum supplementation during spheroid formation on their chemotherapeutic response. Spheroids displayed augmented chemoresistance in comparison to monolayer culturing. This resistance was further increased by the simultaneous presence of both extracellular matrix and high serum concentration during spheroid formation. Following exposure to chemotherapeutics, cell death profiles were not uniform throughout the spheroid. The highest cell death fraction was found at the center of the spheroid and the lowest at the periphery. Collectively, the results demonstrate the validity of the approach, and provide the basis for further investigation of chemotherapeutic responses in ovarian cancer using microfluidics technology. In the future, such microdevices could provide the framework to assay drug sensitivity in a timeframe suitable for clinical decision making

    Electrochemical activation and inhibition of neuromuscular systems through modulation of ion concentrations with ion-selective membranes

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    Conventional functional electrical stimulation aims to restore functional motor activity of patients with disabilities resulting from spinal cord injury or neurological disorders. However, intervention with functional electrical stimulation in neurological diseases lacks an effective implantable method that suppresses unwanted nerve signals. We have developed an electrochemical method to activate and inhibit a nerve by electrically modulating ion concentrations in situ along the nerve. Using ion-selective membranes to achieve different excitability states of the nerve, we observe either a reduction of the electrical threshold for stimulation by up to approximately 40%, or voluntary, reversible inhibition of nerve signal propagation. This low-threshold electrochemical stimulation method is applicable in current implantable neuroprosthetic devices, whereas the on-demand nerve-blocking mechanism could offer effective clinical intervention in disease states caused by uncontrolled nerve activation, such as epilepsy and chronic pain syndromes.Massachusetts Institute of Technology. Faculty Discretionary Research FundNational Institutes of Health (U.S.) (Award UL1 RR 025758)Harvard Catalyst (Grant

    A dualistic model of primary anal canal adenocarcinoma with distinct cellular origins, etiologies, inflammatory microenvironments and mutational signatures: implications for personalised medicine.

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    Primary adenocarcinoma of the anal canal is a rare and aggressive gastrointestinal disease with unclear pathogenesis. Because of its rarity, no clear clinical practice guideline has been defined and a targeted therapeutic armamentarium has yet to be developed. The present article aimed at addressing this information gap by in-depth characterising the anal glandular neoplasms at the histologic, immunologic, genomic and epidemiologic levels. In this multi-institutional study, we first examined the histological features displayed by each collected tumour (n = 74) and analysed their etiological relationship with human papillomavirus (HPV) infection. The intratumoural immune cell subsets (CD4, CD8, Foxp3), the expression of immune checkpoints (PD-1, PD-L1), the defect in mismatch repair proteins and the mutation analysis of multiple clinically relevant genes in the gastrointestinal cancer setting were also determined. Finally, the prognostic significance of each clinicopathological variable was assessed. Phenotypic analysis revealed two region-specific subtypes of anal canal adenocarcinoma. The significant differences in the HPV status, density of tumour-infiltrating lymphocytes, expression of immune checkpoints and mutational profile of several targetable genes further supported the separation of these latter neoplasms into two distinct entities. Importantly, anal gland/transitional-type cancers, which poorly respond to standard treatments, displayed less mutations in downstream effectors of the EGFR signalling pathway (i.e., KRAS and NRAS) and demonstrated a significantly higher expression of the immune inhibitory ligand-receptor pair PD-1/PD-L1 compared to their counterparts arising from the colorectal mucosa. Taken together, the findings reported in the present article reveal, for the first time, that glandular neoplasms of the anal canal arise by HPV-dependent or independent pathways. These etiological differences leads to both individual immune profiles and mutational landscapes that can be targeted for therapeutic benefits

    IL-1β Suppresses Innate IL-25 and IL-33 Production and Maintains Helminth Chronicity.

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    Approximately 2 billion people currently suffer from intestinal helminth infections, which are typically chronic in nature and result in growth retardation, vitamin A deficiency, anemia and poor cognitive function. Such chronicity results from co-evolution between helminths and their mammalian hosts; however, the molecular mechanisms by which these organisms avert immune rejection are not clear. We have found that the natural murine helminth, Heligmosomoides polygyrus bakeri (Hp) elicits the secretion of IL-1β in vivo and in vitro and that this cytokine is critical for shaping a mucosal environment suited to helminth chronicity. Indeed in mice deficient for IL-1β (IL-1β(-/-)), or treated with the soluble IL-1βR antagonist, Anakinra, helminth infection results in enhanced type 2 immunity and accelerated parasite expulsion. IL-1β acts to decrease production of IL-25 and IL-33 at early time points following infection and parasite rejection was determined to require IL-25. Taken together, these data indicate that Hp promotes the release of host-derived IL-1β that suppresses the release of innate cytokines, resulting in suboptimal type 2 immunity and allowing pathogen chronicity
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