525 research outputs found
ECO-DISTRICTS AND SUSTAINABLE CITIES - INSTITUTIONALIZATION THROUGH EXPERIMENTATION
International audienceJudging from the number of communities and cities striving or claiming to be sustainable and how often eco-development is invoked as the means for urban regeneration, it appears that sustainable and eco-development have become "the leading paradigm within urban development" (Whitehead 2003). But what is it that is driving these urban transformations? Clearly, there are many probable answers to this complex question and in what follows we will focus on one particular catalyst of change - urban design competitions. Considered as field changing events (Lampel & Meyer 2008, Anand and Jones 2008), urban design competitions are understudied mechanisms for bringing about field level changes. This paper examines how urban design competitions can bring about changes within two types of fields - professional fields and local geographical fields. The context for our study is urban regeneration in two cities in France and Denmark, both of which have been suffering from industrial decline and have invested in establishing "eco-districts". Based on these two case studies we explore how the different parties involved in these urban development projects have developed innovative design templates and practices that can instantiate field level changes
INNOVATION IN SUSTAINABLE CONSTRUCTION: ECO-CITIES AND SOCIAL HOUSING IN FRANCE AND DENMARK
International audienceThe construction sector is often characterized as a reactive sector, as lagging behind other sectors of the economy, notably industry, when it comes to innovation; as mechanically responding to external (client) needs and implementing innovations that originate elsewhere (Winch 1998, Harty 2008). The sector is often presented as un-dynamic and un-innovative and as precluding novel design practices and tools, an orientation that seems to flow from its rigid routines, professional boundaries, division of labor, national legislation, established performance measures, and fixed ideas about best practices. Accordingly, building projects in the construction sector tend to reflect objectives and institutionalized practices other than those related to innovation and sustainability
Institutionalization Through Experimentation
Judging from the number of communities and cities striving or claiming to be sustainable and how often eco-development is invoked as the means for urban regeneration, it appears that sustainable and eco-development have become âthe leading paradigm within urban developmentâ (Whitehead 2003). But what is it that is driving these urban transformations? Clearly, there are many probable answers to this complex question and in what follows we will focus on one particular catalyst of change â urban design competitions. Considered as field changing events (Lampel & Meyer 2008, Anand and Jones 2008), urban design competitions are understudied mechanisms for bringing about field level changes. This paper examines how urban design competitions can bring about changes within two types of fields â professional fields and local geographical fields. The context for our study is urban regeneration in two cities in France and Denmark, both of which have been suffering from industrial decline and have invested in establishing âeco-districtsâ. Based on these two case studies we explore how the different parties involved in these urban development projects have developed innovative design templates and practices that can instantiate field level changes
Optical Probing of Ultrafast Laser-Induced Solid-to-Overdense-Plasma Transitions
Understanding the target dynamics during its interaction with a relativistic
ultrashort laser pulse is a challenging fundamental multi-physics problem
involving at least atomic and solid-state physics, plasma physics, and laser
physics. Already, the properties of the so-called pre-plasma formed as the
laser pulse's rising edge ionizes the target are complicated to access in
experiments and modeling, and many aspects of this laser-induced transition
from solid to overdense plasma over picosecond time scales are still open
questions. At the same time, applications like laser-driven ion acceleration
require precise knowledge and control of the pre-plasma because the efficiency
of the acceleration process itself crucially depends on the target properties
at the arrival of the relativistic intensity peak of the pulse. By capturing
the dynamics of the initial stage of the interaction, we report on a detailed
visualization of the pre-plasma formation and evolution. Nanometer-thin
diamond-like carbon foils are shown to transition from solid to plasma during
the laser rising edge with intensities < 10^16 W/cm^2. Single-shot
near-infrared probe transmission measurements evidence sub-picosecond dynamics
of an expanding plasma with densities above 10^23 cm^-3 (about 100 times the
critical plasma density). The complementarity of a solid-state interaction
model and a kinetic plasma description provides deep insight into the interplay
of ionization, collisions, and expansion
Disease Severity and Progression in Progressive Supranuclear Palsy and Multiple System Atrophy: Validation of the NNIPPS â PARKINSON PLUS SCALE
BACKGROUND
The Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS) study was a large phase III randomized placebo-controlled trial of riluzole in Progressive Supranuclear Palsy (PSP, n = 362) and Multiple System Atrophy (MSA, n = 398). To assess disease severity and progression, we constructed and validated a new clinical rating scale as an ancillary study.
METHODS AND FINDINGS
Patients were assessed at entry and 6-montly for up to 3 years. Evaluation of the scale's psychometric properties included reliability (n = 116), validity (n = 760), and responsiveness (n = 642). Among the 85 items of the initial scale, factor analysis revealed 83 items contributing to 15 clinically relevant dimensions, including Activity of daily Living/Mobility, Axial bradykinesia, Limb bradykinesia, Rigidity, Oculomotor, Cerebellar, Bulbar/Pseudo-bulbar, Mental, Orthostatic, Urinary, Limb dystonia, Axial dystonia, Pyramidal, Myoclonus and Tremor. All but the Pyramidal dimension demonstrated good internal consistency (Cronbach α ℠0.70). Inter-rater reliability was high for the total score (Intra-class coefficient = 0.94) and 9 dimensions (Intra-class coefficient = 0.80-0.93), and moderate (Intra-class coefficient = 0.54-0.77) for 6. Correlations of the total score with other clinical measures of severity were good (rho ℠0.70). The total score was significantly and linearly related to survival (p<0.0001). Responsiveness expressed as the Standardized Response Mean was high for the total score slope of change (SRM = 1.10), though higher in PSP (SRM = 1.25) than in MSA (SRM = 1.0), indicating a more rapid progression of PSP. The slope of change was constant with increasing disease severity demonstrating good linearity of the scale throughout disease stages. Although MSA and PSP differed quantitatively on the total score at entry and on rate of progression, the relative contribution of clinical dimensions to overall severity and progression was similar.
CONCLUSIONS
The NNIPPS-PPS has suitable validity, is reliable and sensitive, and therefore is appropriate for use in clinical studies with PSP or MSA.
TRIAL REGISTRATION
ClinicalTrials.gov NCT00211224
Georg Schmorl prize of the German spine society (DWG) 2022: current treatment for inpatients with osteoporotic thoracolumbar fractures-results of the EOFTT study
AIM
Osteoporotic thoracolumbar fractures are of increasing importance. To identify the optimal treatment strategy this multicentre prospective cohort study was performed.
PURPOSE
Patients suffering from osteoporotic thoracolumbar fractures were included. Excluded were tumour diseases, infections and limb fractures. Age, sex, trauma mechanism, OFÂ classification, OF-score, treatment strategy, pain condition and mobilization were analysed.
METHODS
A total of 518 patients' aged 75â±â10 (41-97) years were included in 17 centre. A total of 174 patients were treated conservatively, and 344 were treated surgically, of whom 310 (90%) received minimally invasive treatment. An increase in the OF classification was associated with an increase in both the likelihood of surgery and the surgical invasiveness.
RESULTS
Five (3%) complications occurred during conservative treatment, and 46 (13%) occurred in the surgically treated patients. 4 surgical site infections and 2 mechanical failures requested revision surgery. At discharge pain improved significantly from a visual analogue scale score of 7.7 (surgical) and 6.0 (conservative) to a score of 4 in both groups (pâ<â0.001). Over the course of treatment, mobility improved significantly (pâ=â0.001), with a significantly stronger (pâ=â0.007) improvement in the surgically treated patients.
CONCLUSION
Fracture severity according to the OF classification is significantly correlated with higher surgery rates and higher invasiveness of surgery. The most commonly used surgical strategy was minimally invasive short-segmental hybrid stabilization followed by kyphoplasty/vertebroplasty. Despite the worse clinical conditions of the surgically treated patients both conservative and surgical treatment led to an improved pain situation and mobility during the inpatient stay to nearly the same level for both treatments
Treatment and Outcome of Osteoporotic Thoracolumbar Vertebral Fractures With Anterior or Posterior Tension Band Failure (OF 5): Short-Term Results From the Prospective EOFTT Multicenter Study.
STUDY DESIGN
Subgroup analysis of a multicenter prospective cohort study.
OBJECTIVE
To analyse surgical strategies applied to osteoporotic thoracolumbar osteoporotic fracture (OF) 5 injuries with anterior or posterior tension band failure and to assess related complications and clinical outcome.
METHODS
A multicenter prospective cohort study (EOFTT) was conducted at 17 spine centers including 518 consecutive patients who were treated for an osteoporotic vertebral fracture (OVF). For the present study, only patients with OF 5 fractures were analysed. Outcome parameters were complications, Visual Analogue Scale (VAS), Oswestry Disability Questionnaire (ODI), Timed Up & Go test (TUG), EQ-5D 5L, and Barthel Index.
RESULTS
In total, 19 patients (78 ± 7 years, 13 female) were analysed. Operative treatment consisted of long-segment posterior instrumentation in 9 cases and short-segment posterior instrumentation in 10 cases. Pedicle screws were augmented in 68 %, augmentation of the fractured vertebra was performed in 42%, and additional anterior reconstruction was done in 21 %. Two patients (11 %) received short-segment posterior instrumentation without either anterior reconstruction or cement-augmentation of the fractured vertebra. No surgical or major complications occurred, but general postoperative complications were observed in 45%. At a follow-up of mean 20 ± 10 weeks (range, 12 to 48 weeks), patients showed significant improvements in all functional outcome parameters.
CONCLUSIONS
In this analysis of patients with type OF 5 fractures, surgical stabilization was the treatment of choice and lead to significant short-term improvement in terms of functional outcome and quality of life despite a high general complication rate
Treatment and Outcome of Osteoporotic Thoracolumbar Vertebral Body Fractures With Deformation of Both Endplates With or Without Posterior Wall Involvement (OF 4): Short-Term Results from the Prospective EOFTT Multicenter Study.
STUDY DESIGN: Multicenter prospective cohort study.
OBJECTIVE: To analyse therapeutical strategies applied to osteoporotic thoracolumbar OF 4 injuries, to assess related complications and clinical outcome.
METHODS: A multicenter prospective cohort study (EOFTT) including 518 consecutive patients who were treated for an Osteoporotic vertebral compression fracture (OVCF). For the present study, only patients with OF 4 fractures were analysed. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5L, and Barthel Index after a minimum follow-up of 6Â weeks.
RESULTS: A total of 152 (29%) patients presented with OF 4 fractures with a mean age of 76 years (range 41-97). The most common treatment was short-segment posterior stabilization (51%; hybrid stabilization in 36%). Mean follow up was 208 days (±131 days), mean ODI was 30 ± 21. Dorsoventral stabilized patients were younger compared to the other groups (P .602, Barthel: P > .252, EQ-5D 5L index value: P > .610, VAS-EQ-5D 5L: P = 1.000). The inpatient complication rate was 8% after conservative and 16% after surgical treatment. During follow-up period 14% of conservatively treated patients and 3% of surgical treated patients experienced neurological deficits.
CONCLUSIONS: Conservative therapy of OF 4 injuries seems to be viable option in patients with only moderate symptoms. Hybrid stabilization was the dominant treatment strategy leading to promising clinical short-term results. Stand-alone cement augmentation seems to be a valid alternative in selected cases
Clinical Evaluation of the Osteoporotic Fracture Treatment Score (OF-Score): Results of the Evaluation of the Osteoporotic Fracture Classification, Treatment Score and Therapy Recommendations (EOFTT) Study.
STUDY DESIGN
Multicenter prospective cohort study.
OBJECTIVE
The study aims to validate the recently developed OF score for treatment decisions in patients with osteoporotic vertebral compression fractures (OVCF).
METHODS
This is a prospective multicenter cohort study (EOFTT) in 17 spine centers. All consecutive patients with OVCF were included. The decision for conservative or surgical therapy was made by the treating physician independent of the OF score recommendation. Final decisions were compared to the recommendations given by the OF score. Outcome parameters were complications, Visual Analogue Scale, Oswestry Disability Questionnaire, Timed Up & Go test, EQ-5D 5Â L, and Barthel Index.
RESULTS
In total, 518 patients (75.3% female, age 75 ± 10) years were included. 344 (66%) patients received surgical treatment. 71% of patients were treated following the score recommendations. For an OF score cut-off value of 6.5, the sensitivity and specificity to predict actual treatment were 60% and 68% (AUC .684, P < .001). During hospitalization overall 76 (14.7%) complications occurred. The mean follow-up rate and time were 92% and 5 ± 3.5 months, respectively. While all patients in the study cohort improved in clinical outcome parameters, the effect size was significantly less in the patients not treated in line with the OF score's recommendation. Eight (3%) patients needed revision surgery.
CONCLUSIONS
Patients treated according to the OF score's recommendations showed favorable short-term clinical results. Noncompliance with the score resulted in more pain and impaired functional outcome and quality of life. The OF score is a reliable and save tool to aid treatment decision in OVCF
Silica burial enhanced by iron limitation in oceanic upwelling margins
In large swaths of the ocean, primary production by diatoms may be limited by the availability of silica, which in turn limits the biological uptake of carbon dioxide. The burial of biogenic silica in the form of opal is the main sink of marine silicon. Opal burial occurs in equal parts in iron-limited open-ocean provinces and upwelling margins, especially the eastern Pacific upwelling zone. However, it is unclear why opal burial is so efficient in this margin. Here we measure fluxes of biogenic material, concentrations of diatom-bound iron and silicon isotope ratios using sediment traps and a sediment core from the Gulf of California upwelling margin. In the sediment trap material, we find that periods of intense upwelling are associated with transient iron limitation that results in a high export of silica relative to organic carbon. A similar correlation between enhanced silica burial and iron limitation is evident in the sediment core, which spans the past 26,000 years. A global compilation also indicates that hotspots of silicon burial in the ocean are all characterized by high silica to organic carbon export ratios, a diagnostic trait for diatoms growing under iron stress. We therefore propose that prevailing conditions of silica limitation in the ocean are largely caused by iron deficiency imposing an indirect constraint on oceanic carbon uptake
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