174 research outputs found
Exploring Thessaloniki: The Evolution and Impact of Urban Public Spaces and Green Areas
Thessaloniki, a bustling and lively city, faces the challenge of limited public and
green spaces amidst its dense urban fabric. Compared to European standards,
Thessaloniki has one of the lowest ratios of green space per resident, with only
2.6 m² per inhabitant (Latinopoulos et al. 2016:132). On average, some 40 %
of the surface area of European cities is made up of urban green infrastructure,
with around 18.2 m2 of publicly accessible green space per inhabitant;
44 % of Europe‘s urban population lives within 300 m of a public park (European
Commission n.d). This suggests that prior policies and initiatives aimed at
tackling this problem have faced significant hurdles and have not yet produced
substantial outcomes (cf. Karagianni 2023). The scarcity of green spaces is
further exacerbated by the city‘s high residential densities (COT 2017). These
circumstances highlight the pressing need for effective interventions and strategies
to enhance the availability and accessibility of public and green spaces
in Thessaloniki. This text primarily focuses on the western part of Thessaloniki
for the analysis of visibility, characteristics/typologies, impact on surroundings,
challenges, and solutions & measures of green spaces. Therefore, this text gives
an overview of the accessibility of green spaces; some are more hidden as
they are small and not in prominent locations, whilst others are very visible due
to their size and location. Further, different typologies of green spaces could
be defined in the study area due to their different characteristics; these include
squares & parks, pathway greenery, tree lines, school courtyards, sports areas,
and open non-designed spaces. Each green space brings a potential to enhance
its surroundings socially, environmentally, and economically. Finally, some
solutions and measures are formulated to combat the challenges the green
spaces of Thessaloniki face. By narrowing the scope to this specific area, we
aim to gain a comprehensive understanding of the dynamics and issues related
to public and green spaces in this particular region of the city
High-order splitting finite element methods for the subdiffusion equation with limited smoothing property
In contrast with the diffusion equation which smoothens the initial data to
for (away from the corners/edges of the domain), the
subdiffusion equation only exhibits limited spatial regularity. As a result,
one generally cannot expect high-order accuracy in space in solving the
subdiffusion equation with nonsmooth initial data. In this paper, a new
splitting of the solution is constructed for high-order finite element
approximations to the subdiffusion equation with nonsmooth initial data. The
method is constructed by splitting the solution into two parts, i.e., a
time-dependent smooth part and a time-independent nonsmooth part, and then
approximating the two parts via different strategies. The time-dependent smooth
part is approximated by using high-order finite element method in space and
convolution quadrature in time, while the steady nonsmooth part could be
approximated by using smaller mesh size or other methods that could yield
high-order accuracy. Several examples are presented to show how to accurately
approximate the steady nonsmooth part, including piecewise smooth initial data,
Dirac--Delta point initial data, and Dirac measure concentrated on an
interface. The argument could be directly extended to subdiffusion equations
with nonsmooth source data. Extensive numerical experiments are presented to
support the theoretical analysis and to illustrate the performance of the
proposed high-order splitting finite element methods.Comment: 25 page
Edge-Assisted V2X Motion Planning and Power Control Under Channel Uncertainty
Edge-assisted vehicle-to-everything (V2X) motion planning is an emerging
paradigm to achieve safe and efficient autonomous driving, since it leverages
the global position information shared among multiple vehicles. However, due to
the imperfect channel state information (CSI), the position information of
vehicles may become outdated and inaccurate. Conventional methods ignoring the
communication delays could severely jeopardize driving safety. To fill this
gap, this paper proposes a robust V2X motion planning policy that adapts
between competitive driving under a low communication delay and conservative
driving under a high communication delay, and guarantees small communication
delays at key waypoints via power control. This is achieved by integrating the
vehicle mobility and communication delay models and solving a joint design of
motion planning and power control problem via the block coordinate descent
framework. Simulation results show that the proposed driving policy achieves
the smallest collision ratio compared with other benchmark policies
Hypoxia associated multi-omics molecular landscape of tumor tissue in patients with hepatocellular carcinoma
The present study was designed to update the knowledge about hypoxia-related multi-omic molecular landscape in hepatocellular carcinoma (HCC) tissues. Large-size HCC datasets from multiple centers were collected. The hypoxia exposure of tumor tissue from patients in 10 HCC cohorts was estimated using a novel HCC-specific hypoxia score system constructed in our previous study. A comprehensive bioinformatical analysis was conducted to compare hypoxia-associated multi-omic molecular features in patients with a high hypoxia score to a low hypoxia score. We found that patients with different exposure to hypoxia differed significantly in transcriptomic, genomic, epigenomic, and proteomic alterations, including differences in mRNA, microRNA (miR), and long non-coding RNA (lncRNA) expression, differences in copy number alterations (CNAs), differences in DNA methylation levels, differences in RNA alternative splicing events, and differences in protein levels. HCC survival-associated molecular events were identified. The potential correlation between molecular features related to hypoxia has also been explored, and various networks have been constructed. We revealed a particularly comprehensive hypoxia-related molecular landscape in tumor tissues that provided novel evidence and perspectives to explain the role of hypoxia in HCC. Clinically, the data obtained from the present study may enable the development of individualized treatment or management strategies for HCC patients with different levels of hypoxia exposure.</p
A Sterol and Spiroditerpenoids from a Penicillium sp. Isolated from a Deep Sea Sediment Sample
A new polyoxygenated sterol, sterolic acid (1), three new breviane spiroditerpenoids, breviones I–K (2–4), and the known breviones (5–8), were isolated from the crude extract of a Penicillium sp. obtained from a deep sea sediment sample that was collected at a depth of 5115 m. The structures of 1–4 were elucidated primarily by NMR experiments, and 1 was further confirmed by X-ray crystallography. The absolute configurations of 2 and 3 were deduced by comparison of their CD spectra with those of the model compounds. Compounds 2 and 5 showed significant cytotoxicity against MCF-7 cells, which is comparable to the positive control cisplatin
Single-cell transcriptomics and In vitro lineage tracing reveals differential susceptibility of human iPSC-derived midbrain dopaminergic neurons in a cellular model of Parkinson's Disease
Advances in stem cell technologies open up new avenues for modelling development and diseases. The success of these pursuits, however, relies on the use of cells most relevant to those targeted by the disease of interest, for example, midbrain dopaminergic neurons for Parkinson’s disease. In the present study, we report the generation of a human induced pluripotent stem cell (iPSC) line capable of purifying and tracing nascent midbrain dopaminergic progenitors and their differentiated progeny via the expression of a Blue Fluorescent Protein (BFP). This was achieved by CRISPR/Cas9-assisted knock-in of BFP and Cre into the safe harbour locus AAVS1 and an early midbrain dopaminergic lineage marker gene LMX1A, respectively. Immunocytochemical analysis and single-cell RNA sequencing of iPSC-derived neural cultures confirm developmental recapitulation of the human fetal midbrain and high-quality midbrain cells. By modelling Parkinson’s disease-related drug toxicity using 1-Methyl-4-phenylpyridinium (MPP+), we showed a preferential reduction of BFP+ cells, a finding demonstrated independently by cell death assays and single-cell transcriptomic analysis of MPP+ treated neural cultures. Together, these results highlight the importance of disease-relevant cell types in stem cell modelling
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