Resumo Em Lisboa, durante o período de pandemia covid19, a ação dos movimentos sociais urbanos acirrou-se, capitalizando a visibilidade para o direito à habitação, como direito humano básico e ...imperativo incondicional de saúde pública, para cumprir os deveres de quarentena e isolamento social, impostos pelo Estado de Excepção. Descrevendo o processo de lutas urbanas, participação e contestação, e ganhos na moratória contra os despejos e pagamento dos alugueres, concluímos que os atores nessa luta urbana têm poder limitado sobre as mudanças que iniciam ou fazem um esforço para infligir, se não estiverem envolvidos em uma ação concertada e politicamente integrada, até porque as conquistas que obtêm são temporárias e excepcionais, à semelhança do próprio estado de emergência imposto pela covid19.
Abstract In Lisbon, during the covid-19 pandemic period, the action of urban social movements was intensified, capitalizing on the visibility of the right to housing as a basic human right and an unconditional public health imperative to fulfill the duties of quarantine and social isolation imposed by the State of Exception. Describing the process of urban struggles, participation and contestation, as well as gains from the moratorium on evictions and rent payments, we conclude that the actors in this urban struggle have limited power over the changes they initiate, or make an effort to inflict, if they are not involved in a concerted and politically integrated action, not least because the achievements they obtain are temporary and exceptional, similar to the state of emergency imposed by covid-19.
Although environmental effects are mostly assessed via standard individual species the ecological relevance of multispecies testing is well-recognized and highly recommended. Hence, the effect of ...copper oxide nanomaterials (CuONM) and CuCl2 were assessed using the validated soil multispecies system (SMS). Besides the individual species (IS) “standard” tests for all, a predation study was done. Toxicity was higher in the SMS than in the IS, and longer exposure showed increased toxicity. The predator (Hypoaspis aculeifer) preyed most on smaller species, but the net biomass consumed was similar across species. Internal Cu in Folsomia candida reached ca. 140 μg Cu/g dry weight, fluctuating over time, especialy for CuCl2. Copper was mostly bound to soil components for both Cu forms (<0.2% of the total Cu in soil solution, < 0.007% on the ionic form, but the soil solution content increased with the total added concentration). Hazard Concentrations (HC5) showed higher toxicity and more similarity between Cu forms at longer-term exposure. Risk of NMs is relatively limited at present (IS based instead of SMS) with short exposure times (i.e., longer is required) and too few IS tested. The impact of species interactions is highlighted and is of key importance to include in ecosystem hazard prediction.
Eisenia andrei
is considered in OECD and ISO guidelines to be a suitable replacement for
Eisenia fetida
in ecotoxicological assays. This suggests that other alternative materials and methods could ...also be used in standard procedures for toxicity testing. The guidelines also favor using less time-consuming procedures and reducing costs and other limitations to ecotoxicological assessments. In recent years, spent coffee grounds (SCG) have been used to produce vermicompost and biochar and as an additive to organic fertilizers. In addition, the physicochemical characteristics of SCG indicate that the material is a suitable substrate for earthworms, with the organisms performing as well as in natural soil. In the present study, a battery of ecotoxicological tests was established with unwashed and washed SCG and a natural reference soil (LUFA 2.2). The test substrates were spiked with different concentrations of silver nitrate. Survival and reproduction of the earthworm
E. andrei
were assessed under different conditions, along with substrate basal respiration (SBR) as a proxy for microbial activity. Seedling emergence and the germination index of
Lepidium sativum
were also determined, following standard guidelines. Exposure to silver nitrate had similar effects on earthworm survival and reproduction, as the estimated effective concentrations (EC
10
and EC
50
) in unwashed SCG and LUFA 2.2 overlapped. A hormetic effect was observed for SBR in LUFA 2.2 spiked with 12.8 mg/kg but not in unwashed SCG. Both SBR and root development were inhibited by similar concentrations of silver nitrate in washed SCG. The findings indicate that unwashed SCG could potentially be used as a substrate in
E. andrei
toxicity tests and support the eventual inclusion of this material in the standard guidelines.
We present novel velocimetry algorithms based on the hybridization of correlation-based Particle Image Velocimetry (PIV) and a combination of Lucas–Kanade and Liu–Shen optical flow (OpF) methods. An ...efficient Aparapi/OpenCL implementation of those methods is also provided in the accompanying open-source QuickLabPIV-ng tool enabled with a Graphical User Interface (GUI). Two different options of hybridization were developed and tested: OpF as a last step, after correlation-based PIV, and OpF as a substitute for sub-pixel interpolation. Hybridization increases the spatial resolution of PIV, enabling the characterization of small turbulent scales and the computation of key turbulence parameters such as the rate of dissipation of turbulent kinetic energy. The method was evaluated using both synthetic and real databases, representing flows that exhibit a variety of locally isotropic homogeneous turbulent scales. The proposed hybrid PIV-OpF results in a 3-fold increase in the PIV density for synthetic images. The analysis of power spectral density functions and auto-correlation demonstrated the impact of PIV image quality on the accuracy of the method and its ability to extend the turbulence range. We discuss the challenges posed by optical noise and tracer density in the quality of the vector map density.
We present a benchmark study of Optical Flow (OpF) methods for fluid mechanics applications. It is aimed at assessing the performance of three OpF methods, Lucas and Kanade (in: Proceedings of the ...7th 1519 international joint conference on artificial intelligence, 1981), Horn and Schunck (AI 17:185–203, 1981) and Farnebäck (Two-frame motion estimation based on polynomial expansion, in: Bigun, Gustavsson (eds) Image analysis, Springer, 2003), combined or not with the Liu and Shen (JFM 614:253–291, 2008) algorithm. The performance of the OpF methods, evaluated exclusively as the difference between the values of the methods and of ground-truth (reference values), is benchmarked for deformation dominated, rotation-dominated and uniform flows. For each flow type, relative and absolute errors are computed for different tracer displacements, noise levels, pixel particle sizes, image bit-depths and particle concentrations. The accuracy of the OpF methods seems mainly affected by the magnitude of velocity gradients and convective accelerations. It does not seem to be affected by the relative preponderance of rotational and deformation components. The inner region of the Poiseuille flow and the saddle point in the Rankine vortex combined with uniform flow pose significant difficulties to all methods. The performance of the Lucas-Kanade/Liu-Shen combination is the best for all flow types, image conditions and image bit depths. The Farnebäck/Liu-Shen combination has a similar high performance but only for image depths of 10 bit or higher. These OpF methods maintain a high performance for tracer sizes and concentrations outside the PIV optimal range. Horn-Schunck is the worst performing method, due to high sensitiveness to particle concentration variations or particle sizes. These results can be used to plan new particle-based velocimetry experiments or to retrieve further information from existing PIV databases.
Graphical abstract
Clinical translation of cell‐based products is hampered by their limited predictive in vivo performance. To overcome this hurdle, engineering strategies advocate to fabricate tissue products through ...processes that mimic development and regeneration, a strategy applicable for the healing of large bone defects, an unmet medical need. Natural fracture healing occurs through the formation of a cartilage intermediate, termed “soft callus,” which is transformed into bone following a process that recapitulates developmental events. The main contributors to the soft callus are cells derived from the periosteum, containing potent skeletal stem cells. Herein, cells derived from human periosteum are used for the scalable production of microspheroids that are differentiated into callus organoids. The organoids attain autonomy and exhibit the capacity to form ectopic bone microorgans in vivo. This potency is linked to specific gene signatures mimicking those found in developing and healing long bones. Furthermore, callus organoids spontaneously bioassemble in vitro into large engineered tissues able to heal murine critical‐sized long bone defects. The regenerated bone exhibits similar morphological properties to those of native tibia. These callus organoids can be viewed as a living “bio‐ink” allowing bottom‐up manufacturing of multimodular tissues with complex geometric features and inbuilt quality attributes.
Developmentally engineered callus organoids allow implementation of bone by design strategies. Callus organoids exhibit a remarkable capacity to form bone microorgans upon implantation. This capacity is linked to specific gene profiles that correspond to developmental and fracture healing processes. When assembled in vitro, the callus organoids fuse resulting in large multimodular implants able to rapidly heal critical‐sized long bone defects.
Repetitive transcranial magnetic stimulation (rTMS) over motor cortex and trans-spinal direct current stimulation (tsDCS) modulate corticospinal circuits in healthy and injured subjects. However, ...their associated effects with physical exercise is still not defined. This study aimed to investigate the effect of three different settings of rTMS and tsDCS combined with treadmill exercise on spinal cord and cortical excitability of healthy subjects. We performed a triple blind, randomized, sham-controlled crossover study with 12 healthy volunteers who underwent single sessions of rTMS (1Hz, 20Hz and Sham) and tsDCS (anodal, cathodal and Sham) associated with 20 minutes of treadmill walking. Cortical excitability was assessed by motor evoked potential (MEP) and spinal cord excitability by the Hoffmann reflex (Hr), nociceptive flexion reflex (NFR) and homosynaptic depression (HD). All measures were assessed before, immediately, 30 and 60 minutes after the experimental procedures. Our results demonstrated that anodal tsDCS/treadmill exercise reduced MEP's amplitude and NFR's area compared to sham condition, conversely, cathodal tsDCS/treadmill exercise increased NFR's area. High-frequency rTMS increased MEP's amplitude and NFR's area compared to sham condition. Anodal tsDCS/treadmill exercise and 20Hz rTMS/treadmill exercise reduced Hr amplitude up to 30 minutes after stimulation offset and no changes were observed in HD measures. We demonstrated that tsDCS and rTMS combined with treadmill exercise modulated cortical and spinal cord excitability through different mechanisms. tsDCS modulated spinal reflexes in a polarity-dependent way acting at local spinal circuits while rTMS probably promoted changes in the presynaptic inhibition of spinal motoneurons. In addition, the association of two neuromodulatory techniques induced long-lasting changes.
In Lisbon, during the COVID‐19 pandemic period, new spaces for contestation and the action of urban social movements intensified, capitalising on the visibility for the right to housing, as a basic ...human right and an unconditional public health imperative, to fulfil the duties of lockdown and social isolation, imposed by the State of Exception. Its narrative and strategies reinforces the counter‐hegemonic movement that denounces the logics of commodification and financialisation in the housing sector, placing hope in a post‐capitalist transition in the post‐COVID horizon. We conclude that the actors in this urban struggle have limited power over the changes they initiate, or make an effort to inflict, if they are not involved in a concerted and politically integrated action, not least because the achievements they obtain are temporary and exceptional, like the state of emergency imposed by COVID‐19.
In Lisbon, during the COVID‐19 pandemic period, urban social movements intensified, capitalizing on the public and political visibility for the right to housing. The social movements argue the right to housing as a basic human right and an unconditional public health imperative, to fulfill the duties of lockdown and social isolation, imposed by the State of Exception. There achievements are limited, because they are temporary and exceptional and are not concerted and politically integrated.
The tree Acacia dealbata is native to Australia but has become invasive in many parts of the world thanks to its N-fixing capacity and to the allelopathic compounds present in its biomass. We ...conducted a pilot-scale study to assess the potential conversion of A. dealbata biomass by vermicomposting via the earthworm Eisenia andrei. The flowering aerial A. dealbata biomass was shredded and placed in a vermireactor under greenhouse conditions for 56 days. The vermicomposted material was sampled every two weeks to analyse its biological and chemical parameters. The phytotoxicity of the fresh A. dealbata material and vermicompost was assessed via an ecotoxicological test with Lepidium sativum seeds. The activity of the earthworms caused strong modifications of the properties of the processed material: the electric conductivity, basal respiration, and organic matter content were reduced, whereas the concentrations of other elements such as N, P, or Zn increased. The earthworm biomass increased steadily until day 42 and then decreased, probably due to the depletion of labile organic matter during the initial stages of vermicomposting. The fresh A. dealbata material reduced the germination and radicle elongation of L. sativum, whereas vermicompost showed the same values as control. The produced vermicompost was an organic fertiliser rich in N and was not phytotoxic. Vermicomposting provides an opportunity to create a new value chain for the control of the invasive tree A. dealbata.
Decellularized extracellular matrix (dECM) is emerging as a valuable tool for generating 3D in vitro tumor models that better recapitulate tumor-stroma interactions. However, the development of ...dECM-3D heterotypic microtumors exhibiting a controlled morphology is yet to be materialized. Precisely controlling microtumors morphologic features is key to avoid an inaccurate evaluation of therapeutics performance during preclinical screening. To address this, herein we employed ultra-low adhesion surfaces for bioengineering organotypic 3D metastatic breast cancer-fibroblast models enriched with dECM microfibrillar fragments, as a bottom-up strategy to include major matrix components and their associated biomolecular cues during the early stages of 3D microtissue spheroids assembly, simulating pre-existing ECM presence in the in vivo setting. This biomimetic approach enabled the self-assembly of dECM-3D tumor-stroma spheroids with tunable size and reproducible morphology. Along time, dECM enriched and stroma-rich microtumors exhibited necrotic core formation, secretion of key biomarkers and higher cancer-cell specific resistance to different chemotherapeutics in comparison to standard spheroids. Exometabolomics profiling of dECM-Spheroid in vitro models further identified important breast cancer metabolic features including glucose/pyruvate consumption and lactate excretion, which suggest an intense glycolytic activity, recapitulating major hallmarks of the native microenvironment. Such organotypic dECM-enriched microtumors overcome the morphologic variability generally associated with cell-laden dECM models, while providing a scalable testing platform that can be foreseeable leveraged for high-throughput screening of candidate therapeutics.
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