4,697 research outputs found
Capacity assessment of railway infrastructure: Tools, methodologies and policy relevance in the EU context
The transport sector is increasingly faced with several issues related to the rising of traffic demand such as congestion, energy
consumption, noise, pollution, safety, etc.. Due to its low external and environmental costs, railway can be considered (together with inland
waterways and short-sea-shipping) as a key factor for the sustainable development of a more competitive and resource-efficient transport
system (European Commission, White Paper 2011). In order to reinforce the role of rail in European transport , there is a strong need of
addressing the efficiency of the system and customers' satisfaction through targeted actions, i.e. rising reliability and quality of service.
This becomes particularly pressing as many parts of the existing railway infrastructures are reaching their maximum capacity thus shrinking
their capability to provide users and customers a higher or even adequate level of service. Taking also into account that transport demand
forecasts for 2030 clearly show a marked increase of rail activity across the whole Europe, we aim to address the issue of rail congestion in
the context of relevant policy questions: Is the actual rail Infrastructure really able to absorb forecasted traffic, without significant impacts
on punctuality of the system? Would the already planned interventions on the European railway infrastructure guarantee an adequate
available capacity and consequently adequate reliability and level of service? To which extent would the coveted competition in an open
railway market be influenced by capacity scarcity, mainly during peak hours or along more profitable corridors?
An accurate estimation of capacity of the rail network can help answer these questions, leading policy makers to better decisions and
helping to minimize costs for users. In this context this report explores the issue of capacity scarcity and sets this issue in the context of
other relevant policy issues (track access charges, cost/benefit and accessibility measures, maintenance programmes, freight services’
reliability, external, marginal congestion or scarcity cost for rail, impacts of climate changes, etc.), providing a methodological review of
capacity and punctuality assessment procedures. To better explore the real applicability and the time and/or data constraints of each
methodology, the study reports some practical applications to the European railway network. Finally in the last section the report discusses
the topic from a modelling perspective, as the quantitative estimation of railway capacity constraints is a key issue in order to provide
better support to transport policies at EU level.JRC.J.1-Economics of Climate Change, Energy and Transpor
International Respiratory Infections Society COVID Research Conversations: Podcast 1 with Dr. Francesco Blasi
Section(s) Topics
1–2 Introductions
3 Foundations of best practice
4 COVID-19 as stimulus for innovation
5 Adapting and evolving therapeutic approach
6 Age and comorbidities as risk factors
7 Over-capacity ICU
8 Adapting the ER for COVID-19
9 Training personnel for COVID-19
10 Psychological support, healthcare heroes, and COVID fatigue
11 Increased oxygen requirement
12–13 Milan’s multi-disciplinary unit
14 Standardizing respiratory support measures
15 Nutrition, sedation, and life support
16 CPAP successes and failures
17 Prone and lateral positioning of patients on CPAP
18 Different COVID-19 phenotypes?
19 Thromboembolism risk score, age, and comorbidities
20 Cardiorespiratory considerations: hypertension, echocardiography
21 Thrombosis and thromboembolism
22 Hypertension and anti-hyperintensive drugs
23 Inflammation and steroid therapies
24 Lung transplantation
25 Possible genetic risk factors
26 Dr. Blasi’s summary
27–28 Hypertension and COVID-19 pneumonia
29–30 Smoking, COPD, bronchiectasis, and cystic fibrosis
31–35 Pathophysiology of COVID-19; treatment with steroids
36–39 Lung transplantation in the Time of COVID
40–41 “COVID fatigue”
42–43 Vaccination
44–45 Thanks and sign-of
Cooperative Interactions between PBX, PREP, and HOX Proteins Modulate the Activity of the α2(V) Collagen (COL5A2) Promoter
Cell type-specific expression of the human alpha2(V) collagen (COL5A2) gene depends on a cis-acting element that consists of two contiguous protein binding sites (FPA and FPB) located between nucleotides -149 and -95, relative to the transcription start site. The present study focused on the characterization of the FPB-bound complex. DNA binding assays and cell transfection experiments revealed that the bipartite core sequence of FPB (5'-ATCAATCA-3') binds the PBX1/2, PREP1, and HOXB1 proteins, and this in turn leads to promoter transactivation. In the presence of all three nuclear factors, cooperative interactions between recombinant PBX1 and PREP1 or PBX1 and HOXB1 result in binding of the heterodimers to FPB in vitro. Similarly, overexpression of different combinations of PBX1, PREP1, and HOXB1 transactivates FPB-driven transcription. In contrast to the composition of the FPB complex purified from COL5A2-positive cells, the FPB complex from COL5A2-negative cells contains PBX2 and PREP1 but lacks PBX1. However, PBX1 exogenously introduced into COL5A2-negative cells cannot stimulate FPB-driven transcription unless co-expressed with PREP1. Within the intrinsic limitations of the experimental model, our results indicate that combinatorial interactions among PBX and PREP or HOX proteins are involved in regulating tissue-specific production of collagen V
Avaliação das alterações da hemostasia e anticorpo anticardiolipina em pacientes com a forma grave da leptospirose
A prospective study was designed to evaluate disorders of hemostasis and levels of anticardiolipin antibodies (ACL) in 30 patients with severe leptospirosis and acute renal failure (ARF) (ARF was defined as serum creatinine >; or = 1.5 mg/dL). The patients had been admitted to the Walter Cantídio University Hospital, São José Infectious Diseases Hospital and General Hospital of Fortaleza, Ceará, from August 1999 to July 2001. They all were male, with a mean age of 32 ± 14 years and with clinical and laboratory diagnoses of ARF leptospirosis. The time elapsed between onset of symptoms and the first hemorrhagic manifestation was 9 ± 4 days. Bleeding was observed in 86% of the patients. Laboratory tests showed significantly high levels of urea (181 ±95 mg/dl), fibrinogen, (515 ± 220 mg/dl), prothrombin time (13.3 ± 0.9 seconds) and low platelet counts (69 ± 65x10³/mm³) on admission. There was no elevation in activated partial thromboplastin time or thrombin time. Levels of IgM and IgG ACL concentrations were significantly increased (p ; ou = 1,5 mg/dl). Os pacientes foram internados no Hospital Universitário Walter Cantídio, Hospital São José de Doenças Infecciosas e Hospital Geral de Fortaleza, Ceará, de agosto/1999 a julho/2001. Todos eram do sexo masculino com idade de 32 ± 14 anos e apresentavam manifestações clínicas com diagnóstico laboratorial de leptospirose associada à IRA. O tempo do início dos sintomas ao aparecimento das manifestações hemorrágicas foi de 9 ± 4 dias. As manifestações hemorrágicas foram observadas em 86% dos pacientes. Dados laboratoriais mostraram níveis significativamente elevados de uréia, 181 ±95 mg/dl; fibrinogênio, 515 ± 220 mg/dl; tempo ativado de protrombina, 13,3 ± 0,9 seg e diminuição das plaquetas, 69 ± 65x10³/mm³ na admissão. Não houve alteração no tempo de trombina e de tromboplastina parcial ativado. Os níveis de ACL IgG e IgM estavam significativamente elevados (p < 0,05) na forma grave da leptospirose quando comparados ao grupo controle (28,5 ± 32,4 vs. 11,5 ± 7,9MPL U/ml e 36,7 ± 36,1 vs. 6,5 ± 2,5 GPL U/ml), respectivamente. A vasculite, trombocitopenia e uremia devem ser consideradas como fatores importantes na patogênese dos distúrbios hemorrágicos observados na forma grave da leptospirose que constituem a principal causa de óbito na doença
Ha-Ras stabilization mediates pro-fibrotic signals in dermal fibroblasts
ABSTRACT:Scleroderma (systemic sclerosis; SSc) is a clinically heterogeneous and often lethal acquired disorder of the connective tissue that is characterized by vascular, immune/inflammatory and fibrotic manifestations. Tissue fibrosis is the main cause of morbidity and mortality in SSc and an unmet medical challenge, mostly because of our limited understanding of the molecular factors and signalling events that trigger and sustain disease progression. Recent evidence has correlated skin fibrosis in SSc with stabilization of proto-oncogene Ha-Ras secondary to auto-antibody stimulation of reactive oxygen species production. The goal of the present study was to explore the molecular connection between Ha-Ras stabilization and collagen I production, the main read-out of fibrogenesis, in a primary dermal fibroblast culture system that replicates the early stages of disease progression in SSc.Forced expression of proto-oncogene Ha-Ras in dermal fibroblasts demonstrated the promotion of an immediate collagen I up-regulation, as evidenced by enhanced activity of a collagen I-driven luciferase reporter plasmid and increased accumulation of endogenous collagen I proteins. Moreover, normal levels of Tgfβ transcripts and active transforming growth factor-beta (TGFβ) implied Ha-Ras stimulation of the canonical Smad2/3 signalling pathway independently of TGFβ production or activation. Heightened Smad2/3 signalling was furthermore correlated with greater Smad3 phosphorylation and Smad3 protein accumulation, suggesting that Ha-Ras may target both Smad2/3 activation and turnover. Additional in vitro evidence excluded a contribution of ERK1/2 signalling to improper Smad3 activity and collagen I production in cells that constitutively express Ha-Ras.Our study shows for the first time that constitutively elevated Ha-Ras protein levels can directly stimulate Smad2/3 signalling and collagen I accumulation independently of TGFβ neo-synthesis and activation. This finding therefore implicates the Ha-Ras pathway with the early onset of fibrosis in SSc and implicitly identifies new therapeutic targets in SSc
Doxycycline delays aneurysm rupture in a mouse model of Marfan syndrome
ObjectivesThoracic aneurysms are the main cardiovascular complication of Marfan syndrome (MFS) resulting in premature death. MFS has been associated with mutations of the gene encoding fibrillin-1 (FBN1), a major constituent of the elastic fibers. Matrix metalloproteinases (MMPs) are important in the pathogenesis of abdominal aortic aneurysms but their precise role in MFS is not clear. Doxycycline is a nonspecific MMP inhibitor. The objective of the study was to determine whether docycycline can attenuate matrix degradation and prolong the survival of mice with MFS.MethodsThe study employed a well-characterized animal model of MFS, namely fibrillin-1 under-expressing mice (mgR/mgR mice) that die spontaneously from rupture of the thoracic aorta between 2 to 4 months of age. Mutant and wild type mice were given doxycycline in their drinking water at a concentration designed to provide 100 mg/kg/day beginning at postnatal day (PD) 1, whereas control mice were given water. Treated mice were divided into two groups. One group of animals was followed until death or for 7 months to determine lifespan. In the second group of mice, the ascending thoracic aortas were collected for histological analysis (H&E staining, trichrome staining) and zymography for examining MMP-2 and MMP-9 levels at 6 weeks.ResultsMMP-2 and MMP-9 levels were higher in the thoracic aorta of mgR/mgR mice compared with wild type littermates. Doxycycline-treated mgR/mgR mice lived 132 ± 14.6 days (n = 16) or significantly longer than untreated mutant mice (79 ± 6.7 days, n = 30) (P < 0.01). Connective tissue staining showed that doxycycline treatment decreased elastic fiber degradation in mgR/mgR mice. Furthermore, mgR/mgR mice treated with doxycycline had lower MMP-2 and MMP-9 levels compared with untreated mgR/mgR mice.ConclusionsThis study demonstrates that doxycycline significantly delays aneurysm rupture in MFS-like mice by inhibiting expression of tissue MMP-2 and MMP-9 and thus, degradation of the elastic matrix. The results suggest that MMPs contribute to the progression of thoracic aneurysm in MFS and that doxycycline has the potential to significantly alter the course of the disease.Clinical RelevanceAortic aneurysms are the main cardiovascular complication of Marfan syndrome (MFS) resulting in premature death. β-blockers offer some benefit but do not address the underlying cause of the progressive aortic degradation. Medical treatment that actually targets recently identified pathogenic factors leading to progressive matrix destruction could significantly impact the clinical course of the disease. A recent study using a mouse model of MFS has demonstrated that TGF- β antibodies or the angiotensin II type I receptor (AT1) antagonist losartan can both effectively rescue aneurysm progression. We have found that doxycycline, a nonspecific inhibitor of matrix metalloproteinases (MMPs), can decrease elastin degradation and prolong the lifespan of genetically engineered mice that mimic the human disease process. Based on these results, further testing may be warranted to determine if doxycycline could favorable impact the natural history of Marfan syndrome
Neural Processing of Tri-Plane Hybrid Neural Fields
Driven by the appealing properties of neural fields for storing and communicating 3D data, the problem of directly processing them to address tasks such as classification and part segmentation has emerged and has been investigated in recent works. Early approaches employ neural fields parameterized by shared networks trained on the whole dataset, achieving good task performance but sacrificing reconstruction quality. To improve the latter, later methods focus on individual neural fields parameterized as large Multi-Layer Perceptrons (MLPs), which are, however, challenging to process due to the high dimensionality of the weight space, intrinsic weight space symmetries, and sensitivity to random initialization. Hence, results turn out significantly inferior to those achieved by processing explicit representations, e.g., point clouds or meshes. In the meantime, hybrid representations, in particular based on tri-planes, have emerged as a more effective and efficient alternative to realize neural fields, but their direct processing has not been investigated yet. In this paper, we show that the tri-plane discrete data structure encodes rich information, which can be effectively processed by standard deep-learning machinery. We define an extensive benchmark covering a diverse set of fields such as occupancy, signed/unsigned distance, and, for the first time, radiance fields. While processing a field with the same reconstruction quality, we achieve task performance far superior to frameworks that process large MLPs and, for the first time, almost on par with architectures handling explicit representations
Regulation of limb patterning by extracellular microfibrils
To elucidate the contribution of the extracellular microfibril–elastic fiber network to vertebrate organogenesis, we generated fibrillin 2 (Fbn2)–null mice by gene targeting and identified a limb-patterning defect in the form of bilateral syndactyly. Digit fusion involves both soft and hard tissues, and is associated with reduced apoptosis at affected sites. Two lines of evidence suggest that syndactily is primarily due to defective mesenchyme differentiation, rather than reduced apoptosis of interdigital tissue. First, fusion occurs before appearance of interdigital cell death; second, interdigital tissues having incomplete separation fail to respond to apoptotic clues from implanted BMP-4 beads. Syndactyly is associated with a disorganized matrix, but with normal BMP gene expression. On the other hand, mice double heterozygous for null Fbn2 and Bmp7 alleles display the combined digit phenotype of both nullizygotes. Together, these results imply functional interaction between Fbn2-rich microfibrils and BMP-7 signaling. As such, they uncover an unexpected relationship between the insoluble matrix and soluble factors during limb patterning. We also demonstrate that the Fbn2- null mutation is allelic to the recessive shaker-with-syndactyly (sy) locus on chromosome 18
Transcription factor KLF7 regulates differentiation of neuroectodermal and mesodermal cell lineages
Previous gene targeting studies in mice have implicated the nuclear protein Krüppel-like factor 7 (KLF7) in nervous system development while cell culture assays have documented its involvement in cell cycle regulation. By employing short hairpin RNA (shRNA)-mediated gene silencing, here we demonstrate that murine Klf7 gene expression is required for in vitro differentiation of neuroectodermal and mesodermal cells. Specifically, we show a correlation of Klf7 silencing with down-regulation of the neuronal marker microtubule-associated protein 2 (Map2) and the nerve growth factor (NGF) tyrosine kinase receptor A (TrkA) using the PC12 neuronal cell line. Similarly, KLF7 inactivation in Klf7-null mice decreases the expression of the neurogenic marker brain lipid-binding protein/fatty acid-binding protein 7 (BLBP/FABP7) in neural stem cells (NSCs). We also report that Klf7 silencing is detrimental to neuronal and cardiomyocytic differentiation of embryonic stem cells (ESCs), in addition to altering the adipogenic and osteogenic potential of mouse embryonic fibroblasts (MEFs). Finally, our results suggest that genes that are key for self-renewal of undifferentiated ESCs repress Klf7 expression in ESCs. Together with previous findings, these results provide evidence that KLF7 has a broad spectrum of regulatory functions, which reflect the discrete cellular and molecular contexts in which this transcription factor operates. © 2010 Elsevier Inc
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