The Internet of Things (IoT) is expected to bring new opportunities for improving several services for the Society, from transportation to agriculture, from smart cities to fleet management. In this ...framework, massive connectivity represents one of the key issues. This is especially relevant when IoT systems are expected to cover a large geographical area or a region not reached by terrestrial network connections. In such scenarios, the usage of satellites might represent a viable solution for providing wide area coverage and connectivity in a flexible and affordable manner. Our paper presents a survey on current solutions for the deployment of IoT services in remote/rural areas by exploiting satellites. Several architectures and technical solutions are analyzed, underlining their features and limitations, and real test cases are presented. It has been highlighted that low-orbit satellites offer an efficient solution to support long-range IoT services, with a good trade-off in terms of coverage and latency. Moreover, open issues, new challenges, and innovative technologies have been focused, carefully considering the perimeter that current IoT standardization framework will impose to the practical implementation of future satellite based IoT systems.
Social Theory and the Politics of Higher Education brings together an international group of scholars who shine a theoretical light on the politics of academic life and higher education. The book ...covers three key areas:
Institutional governance, with a specific focus on issues such as measurement, surveillance, accountability, regulation, performance and institutional reputation.Academic work, covering areas such as the changing nature of academic labour, neoliberalism and academic identity, and the role of gender and gender studies in university life.Student experience, which includes case studies of student politics and protest, the impact of graduate debt and changing student identities. The editors and chapter authors explore these topics through a theoretical lens, using the ideas of Michel Foucault, NiklasLuhmann, Barbara Adams, Donna Massey, Margaret Archer, Jürgen Habermas, Pierre Bourdieu, Hartmut Rosa, Norbert Elias and Donna Haraway, among others. The case studies, from Africa, Europe, Australia and South America, draw on a wide range of research approaches, and each chapter includes a set of critical reflections on how social theory and research methodology can work in tandem.
Summary
AIR9 is a cytoskeleton‐associated protein in Arabidopsis thaliana with roles in cytokinesis and cross wall maturation, and reported homologues in land plants and excavate protists, including ...trypanosomatids. We show that the Trypanosoma brucei AIR9‐like protein, TbAIR9, is also cytoskeleton‐associated and colocalizes with the subpellicular microtubules. We find it to be expressed in all life cycle stages and show that it is essential for normal proliferation of trypanosomes in vitro. Depletion of TbAIR9 from procyclic trypanosomes resulted in increased cell length due to increased microtubule extension at the cell posterior. Additionally, the nucleus was re‐positioned to a location posterior to the kinetoplast, leading to defects in cytokinesis and the generation of aberrant progeny. In contrast, in bloodstream trypanosomes, depletion of TbAIR9 had little effect on nucleus positioning, but resulted in aberrant cleavage furrow placement and the generation of non‐equivalent daughter cells following cytokinesis. Our data provide insight into the control of nucleus positioning in this important pathogen and emphasize differences in the cytoskeleton and cell cycle control between two life cycle stages of the T. brucei parasite.
Damming of large rivers has promoted well‐documented ecosystem changes that constitute critical threats to freshwater fish biodiversity. However, it is unclear how trait–environment relationships ...drive community assembly in older (>50 years) tropical river‐reservoir systems. We assessed physical features filtering functional traits (RLQ and fourth‐corner approaches) in seven tropical reservoirs along a major river, in southeastern Brazil, and correlated taxonomic and functional counterparts of local and beta diversity to assess niche‐based assembly processes under prevailing environmental conditions (null model approach). Lower littoral habitat availability (smaller area, volume, and riverine influence) favored species inhabiting open areas that feed on the bottom (mostly migratory species). Downstream position (lower elevation and inflow of water from the mainstem) allowed migrators to enter the reservoirs and promoted environmental heterogeneity, favoring detritivores, invertivores, and carnivorous generalists. Total blocking of the main channel excluded most migratory species from reservoirs at upstream reaches, whereas higher riverine influence and hydrological stability (larger area, volume, and water residence time) favored small‐sized sedentary species (omnivores and piscivores with parental care, mostly non‐native species) in the littoral zone. Correlations differing from null expectations for alpha diversity and nestedness revealed that niche‐based processes support species richness and loss under higher riverine influence and hydrological stability. Our study supports the importance of physical features to set functional spaces available for fish species, but random processes that boost taxonomic differences between reservoirs, largely related to non‐native species introductions, are the primary drivers of fish assemblage structure in tropical reservoirs long‐term disconnected from riverine dynamics.
The antimicrobial activities of the isomers and enantiomers of pinene were evaluated against bacterial and fungal cells. The agar diffusion test showed that only the positive enantiomers of the α- ...and β-isomers of pinene were active. The minimal inhibitory concentration (MIC) and minimal microbicidal concentration (MMC) of these monoterpenes were also determined, confirming that the positive enantiomers exhibited microbicidal activity against all fungi and bacteria tested with MICs ranging from 117 to 4,150 μg/mL. However, no antimicrobial activity was detected with the negative enantiomers up to 20 mg/mL. Time-kill curves showed that (+)-α-pinene and (+)-β-pinene were highly toxic to Candida albicans, killing 100% of inoculum within 60 min. By contrast, the bactericidal effect occurred after 6 h in methicillin-resistant Staphylococcus aureus (MRSA). In combination with commercial antimicrobials, ciprofloxacin plus (+)-α-pinene or (+)-β-pinene presented synergistic activity against MRSA whereas an indifferent effect against all fungi was detected when amphotericin B was combined with the positive enantiomers of pinene. The potential of (+)-α-pinene and (+)-β-pinene to inhibit phospholipase and esterase activities was also evaluated, and the best inhibition results were obtained with Cryptococcus neoformans. C. albicans biofilm formation was prevented with the MIC concentration of (+)-α-pinene and twice the MIC value of (+)-β-pinene. Finally, the cytotoxicity of the positive enantiomers of pinene to murine macrophages was evaluated, and 250 μg/mL of (+)-α-pinene and (+)-β-pinene reduced the cell viability to 66.8% and 57.7%, respectively.
With the growth of nanotechnology and widespread use of nanomaterials, there is an increasing risk of environmental contamination by nanomaterials. However, the potential implications of such ...environmental contamination are hard to evaluate since the toxicity of nanomaterials if often not well characterized. The objective of this study was to evaluate the toxicity of a chromium-based nanoparticle, Cr2O3-NP, used in a wide diversity of industrial processes and commercial products, on the unicellular green alga Chlamydomonas reinhardtii. The deleterious impacts of Cr2O3-NP were characterized using cell density measurements, production of reactive oxygen species (ROS), esterase enzymes activity, and photosystem II electron transport as indicators of toxicity. Cr2O3-NP exposure inhibited culture growth and significantly lowered cellular Chlorophyll a content. From cell density measurements, EC50 values of 2.05±0.20 and 1.35±0.06gL−1 Cr2O3-NP were obtained after 24 and 72h of exposure, respectively. In addition, ROS levels were increased to 160.24±2.47% and 59.91±0.15% of the control value after 24 and 72h of exposition to 10gL−1 Cr2O3-NP. At 24h of exposure, the esterase activity increased to 160.24% of control value, revealing a modification of the short-term metabolic response of algae to Cr2O3-NP exposure. In conclusion, the metabolism of C. reinhardtii was the most sensitive to Cr2O3-NP after 24h of treatment.
Display omitted
•Cr2O3 nanoparticles are unstable and form large aggregates in the medium.•EC50 for growth inhibition of C. reinhardtii is 1.35gL−1 at 72h.•Cr2O3 nanoparticles increase ROS levels at 10gL−1.•Cr2O3 nanoparticles affect photosynthetic electron transport.
Programmable virtualized networks decouple data and control planes and have the power of supporting the demands of diverse and varied use cases, allowing the services to scale and adapt dynamically. ...The diverse demands of Enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low-latency Communications (uRLLC), and massive Machine Type Communications (mMTC) users inevitably increase the network complexity, making programmability alone not sufficient. To fulfill these demands, next generation mobile networks need to respond with the capacity of supporting a greater number of heterogeneous devices, the availability of more spectrum and the introduction of complex protocol stacks, making automated and intelligent tools for management, reconfiguration, adaptation, and coordination of network resources an impelling necessity.
Increases in temperatures over the last century, more intensively after the eighties, were recorded in several databases for the south‐eastern Brazil. These increases are likely to change fish ...communities in aquatic systems by decreasing abundances, biomass and sizes of some species more sensitive to climate change. Reservoirs may be particularly susceptible to the effects of climate change, as they isolate previously connected areas limiting fish dispersal and migration, as well as increasing water temperature and thermal stratification. We assessed temporal changes in the abundance and biomass of the ichthyofauna in an isolate reservoir (inflowing waters from small tributaries in a highland region) aiming to associate changes with climate effects over three decades (1990, 2000, 2010). Two abundant native species, a loricariid Loricariichthys castaneus (Castelnau, 1855) and a cichlid Geophagus brasiliensis (Quoy & Gaimard, 1824), were selected to assess eventual response to climate changes in their geographical distribution in the Southeast Atlantic Hydrographic Region, considering different carbon emission scenarios using ecological niche models. A decrease in the densities and biomass of the ichthyofauna and of the two selected species were observed in both summer and winter over the three decades, coinciding with increases in temperatures. These decreases were correlated with increases in positive anomalies of temperature, which may be an indicator of climatic changes, although with low explanation of the data variation. The mean size of L. castaneus decreased between the nineties and 2010, whereas no significant trend was found for the size of G. brasiliensis. Our predictions of new area for future adequacy indicated a loss in the distribution area for both species (mainly for G. brasiliensis), considering the most pessimistic scenario for 2050 and 2070, possibly due to climatic changes. Both hydroelectric dams and global warming pose threats to freshwater fish diversity, and both will interact. Changes observed in the fish assemblage over the last decades were essential for an assessment of the consequences of global warming in this type of reservoir combining larger scale studies with future projections.
is a versatile bacterium capable of adapting to a wide range of stress factors, including solar UVA radiation (400-315 nm). High UVA doses produce lethal effects due to the action of reactive oxygen ...species. Sublethal UVA doses also induces oxidative damage, but, in addition, it triggers a variety of adaptive responses, including the overexpression of
and
genes in
. These genes encode the synthesis of Pel and Psl, which are essential polysaccharides in biofilm formation. The present study analysed the role of Pel and Psl in the adaptive responses generated by exposure to low UVA doses, and their importance in the response to lethal doses of UVA, hydrogen peroxide (H
O
), and sodium hypochlorite, in both planktonic cells and submerged and air-liquid interface (ALI) biofilms. It also studied the roles of Pel and Psl in
interaction. The results demonstrate that the capacity of sublethal UVA exposure to increase cell hydrophobicity and cell attachment and generate cross-protection phenomena in
depends on the presence of Pel and Psl. The study also shows that Pel and Psl have a key role in the tolerance to lethal doses of UVA radiation, sodium hypochlorite and H
O
, in both biofilms and planktonic cells. Finally, co-culture assays showed total inhibition of
growth in presence of
. This phenomenon depends, at least in part, on the simultaneous presence of Pel and Psl in planktonic cells and biofilms, suggesting a relevant role of these polysaccharides in the interaction between these species.
PDF
