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Quantitative plant biology is an interdisciplinary field that builds on a long history of biomathematics and biophysics. Today, thanks to high spatiotemporal resolution tools and computational modelling, it sets a new standard in plant science. Acquired data, whether molecular, geometric or mechanical, are quantified, statistically assessed and integrated at multiple scales and across fields. They feed testable predictions that, in turn, guide further experimental tests. Quantitative features such as variability, noise, robustness, delays or feedback loops are included to account for the inner dynamics of plants and their interactions with the environment. Here, we present the main features of this ongoing revolution, through new questions around signalling networks, tissue topology, shape plasticity, biomechanics, bioenergetics, ecology and engineering. In the end, quantitative plant biology allows us to question and better understand our interactions with plants. In turn, this field opens the door to transdisciplinary projects with the society, notably through citizen science.
Introduction: Low acuity patients have been controversially tagged as a source of emergency department (ED) misuse. Authorities for many Canadian health regions have set up policies so these patients preferably present to walk-in clinics (WIC). We compared the cost and quality of the care given to low acuity patients in an academic ED and a WIC of Québec City during fiscal year 2015-16. Methods: We conducted an ambidirectional (prospective and retrospective) cohort study using a time-driven activity-based costing method. This method uses duration of care processes (e.g., triage) to allocate to patient care all direct costs (e.g., personnel, consumables), overheads (e.g., building maintenance) and physician charges. We included consecutive adult patients, ambulatory at all time and discharged from the ED or WIC with a diagnosis of upper respiratory tract infection (URTI), urinary tract infection (UTI) or low back pain. Mean cost [95%CI] per patient per condition was compared between settings after risk-adjustment for age, sex, vital signs, number of regular medications and co-morbidities using generalized log-gamma regression models. Proportions [95%CI] of antibiotic prescription and chest X-Ray use in URTI, compliance with provincial guidelines on use of antibiotics in UTI, and column X-Ray use in low back pain were compared between settings using a Pearson Chi-Square test. Results: A total of 409 patients were included. ED and WIC groups were similar in terms of age, sex and vital signs on presentation, but ED patients had a greater burden of comorbidities. Adjusted mean cost (2016 CAN$) of care was significantly higher in the ED than in the WIC (p < 0.0001) for URTI (78.42[64.85-94.82] vs. 59.43[50.43-70.06]), UTI (78.88[69.53-89.48] vs. 53.29[43.68-65.03]), and low back pain (87.97[68.30-113.32] vs. 61.71[47.90-79.51]). For URTI, antibiotics were more frequently prescribed in the WIC (44.1%[34.3-54.3] vs. 5.8%[1.2-16.0]; p < 0.0001) and chest X-Rays, more frequently used in the ED (26.9%[15.6-41.0] vs. 13.7%[7.7-22.0]; p = 0.05). No significant differences were observed in the compliance with guidelines on use of antibiotics in UTI and in the use of column X-Ray in low back pain. Conclusion: Total cost of care for low acuity patients is lower in walk-in clinics than in EDs. However, our results suggest that quality-of-care issues should be considered in determining the best alternate setting for treating ambulatory emergency patients.
Late-life depression (LLD) is associated with a decline in physical activity. Typically this is assessed by self-report questionnaires and, more recently, with actigraphy. We sought to explore the utility of a bespoke activity monitor to characterize activity profiles in LLD more precisely.
The activity monitor was worn for 7 days by 29 adults with LLD and 30 healthy controls. Subjects underwent neuropsychological assessment and quality of life (QoL) (36-item Short-Form Health Survey) and activities of daily living (ADL) scales (Instrumental Activities of Daily Living Scale) were administered.
Physical activity was significantly reduced in LLD compared with controls (t = 3.63, p < 0.001), primarily in the morning. LLD subjects showed slower fine motor movements (t = 3.49, p < 0.001). In LLD patients, activity reductions were related to reduced ADL (r = 0.61, p < 0.001), lower QoL (r = 0.65, p < 0.001), associative learning (r = 0.40, p = 0.036), and higher Montgomery–Åsberg Depression Rating Scale score (r = −0.37, p < 0.05).
Patients with LLD had a significant reduction in general physical activity compared with healthy controls. Assessment of specific activity parameters further revealed the correlates of impairments associated with LLD. Our study suggests that novel wearable technology has the potential to provide an objective way of monitoring real-world function.
The aim of this paper is to show that historical technical archives and complementary physico-chemical studies can be combined to obtain relevant information on the materials and processes used in the manufacturing of a Breguet 765 Sahara airplane. This will be useful both in history of sciences and technology and in the renovation of this more than fifty years old airplane.
The Breguet 765 Sahara plane is the last version of a family of French double-deck transport aircraft produced by Breguet between 1948 and 1960. The gathering of multi-disciplinary information from the literature of the period of production with laboratory investigations has revealed that a “new” aluminum-copper-magnesium alloy was used in the rivets of the Breguet 765. The A-U3G alloy was developed to meet properties requirements of the aeronautical industry for joining sheets of aluminum and was used in the Breguet 765 Sahara to strengthen the joints. Analytical techniques included TEM, EPMA microprobe and metallography.
In the context of the preservation of the cultural heritage, it is important to understand the alteration mechanisms of the materials constituting historical monuments and architecture. Limestone especially is widely used in many French monuments exposed to an urban aggressive atmosphere affecting their durability. To better understand the alteration mechanisms, the first step is to characterize at different scales the stone material properties. In one hand, the pore network that drives the fluids transfer inside the materials was characterized. And on the other hand, the alteration layer formed on several decades aged materials was studied. Results on this fine-scale characterization are discussed.
We theoretically and experimentally investigate a novel modulation concept on silicon (Si) based on the combination of quantum confinement and plasmon enhancement effects. We experimentally study the suitability of Ge/SiGe quantum wells (QWs) on Si as the active material for a plasmon-enhanced optical modulator. We demonstrate that in QW structures absorption and modulation of light with transverse magnetic (TM) polarization are greatly enhanced due to favorable selection rules. Later, we theoretically study the plasmon propagation at the metal-Ge/SiGe QW interface. We design a novel Ge/SiGe QW structure that allows maximized overlap between the plasmonic mode and the underlying Ge/SiGe QWs.
Here we present the installation and successful commissioning of an L'-band Annular Groove Phase Mask (AGPM) coronagraph on VLT/NACO. The AGPM is a vector vortex coronagraph made from diamond subwavelength gratings tuned to the L' band. The vector vortex coronagraph enables high contrast imaging at very small inner working angle (here 0″.09, the diffraction limit of the VLT at L'), potentially being the key to a new parameter space. During technical and science verification runs, we discovered a late-type companion at two beamwidths from an F0V star (Mawet et al. 2013), and imaged the inner regions of β Pictoris down to the previously unexplored projected radius of 1.75 AU. The circumstellar disk was also resolved from ≃ 1″ to 5″ (see J. Milli et al., these proceedings). These results showcase the potential of the NACO L-band AGPM over a wide range of spatial scales.
Fifty years after the hyporheic zone was first defined (Orghidan, 1959), there are still gaps in the knowledge regarding the role of biodiversity in hyporheic processes. First, some methodological questions remained unanswered regarding the interactions between biodiversity and physical processes, both for the study of habitat characteristics and interactions at different scales. Furthermore, many questions remain to be addressed to help inform our understanding of invertebrate community dynamics, especially regarding the trophic niches of organisms, the functional groups present within sediment, and their temporal changes. Understanding microbial community dynamics would require investigations about their relationship with the physical characteristics of the sediment, their diversity, their relationship with metabolic pathways, their interactions with invertebrates, and their response to environmental stress. Another fundamental research question is that of the importance of the hyporheic zone in the global metabolism of the river, which must be explored in relation to organic matter recycling, the effects of disturbances, and the degradation of contaminants. Finally, the application of this knowledge requires the development of methods for the estimation of hydrological exchanges, especially for the management of sediment clogging, the optimization of self-purification, and the integration of climate change in environmental policies. The development of descriptors of hyporheic zone health and of new metrology is also crucial to include specific targets in water policies for the long-term management of the system and a clear evaluation of restoration strategies.
The copper precursor N,N'-diisopropylacetamidinate has been decomposed at low temperature (80-110°C) in a liquid process under a moderate H2 pressure. Depending on the choice of the solvent, the process leads to a colloidal solution of well controlled copper nanoparticles or the deposition of composite Cu-SiO2 films on the surfaces. The latter layer is highly adhesive to silica surface, behaves as an active seed layer for electroless copper deposition and allows a conformal covering inside deep trenches.
This work aims at attaining a more complete understanding of the principles governing resistive contrast imaging (RCI) of copper/low-k interconnects used for dielectric breakdown studies in a nanoprober scanning electron microscope (SEM) system. RCI is employed in such in situ dielectric breakdown studies to facilitate the localization of interconnect defect sites related to various stages in the degradation process of the low-k dielectric material. This work shows that RCI is suitable for detecting high-resistance sites, like opens, in copper/low-k interconnects. Moreover, RCI demonstrates potential in locating defects that lie deep in the test structure and are, thus, not detectable by SEM. A model is also proposed to explain the formation of RCI images of specific interconnect test structures with complex layout.
We have undertaken an adaptive optics imaging survey of extra-solar planetary systems and stars showing interesting radial velocity trends from high precision radial velocity searches. Adaptive Optics increases the resolution and dynamic range of an image, substantially improving the detectability of faint close companions. This survey is sensitive to objects less luminous than the bottom of the main sequence at separations as close as 1″. We have detected stellar companions to the planet bearing stars HD 114762 and Tau Boo. We have also detected a companion to the non-planet bearing star 16 Cyg A.
The Mössbauer spectroscopy is an efficient experimental tool to study lithium insertion mechanisms in negative electrodes of Li-ion batteries at the atomic scale. However, a quantitative interpretation of the experimental data is often difficult due to the complexity of the spectra and we propose to use first-principle calculations of the hyperfine parameters. Three different types of negative electrode materials are considered. First, the experimental 119Sn Mössbauer spectrum obtained for the insertion of 3.5 Li into SnO is compared to the theoretical spectrum, which clearly establishes the existence of Li-Sn stable phases. Then, the analysis of the 121Sb Mössbauer spectra for metal antimonides at the end of the first discharge shows different behaviours depending on the lithium rate. Finally, tin and iron doped titanates are considered to study changes in Ti local environments during lithium insertion.
Background: Studies on normal aging and cognitive functioning commonly describe early and more pronounced age-related changes in executive functions (EFs) compared to other cognitive abilities. Two of the three most common neurodegenerative disorders associated with aging (vascular dementia [VaD] and extrapyramidal [EP]-related dementia) show executive dysfunctions in their clinical presentation; and these cognitive deficits are not uncommon in the third one: Alzheimer's disease (AD). Methods: Nine EF tests (yielding 12 measures) were administered to 123 randomly selected community dwellers, aged 81 years and over, with the view to determine the effect of age on performance. Markers of AD, VaD, and EP-related dementia, as well as sociodemographic and psychological variables, were selected and their contribution to EF performance was investigated. Results: Multiple linear regression analyses revealed the greatest contribution to EF scores from the markers of AD and estimated IQ but not from the markers of VaD and EP-related dementia or from age. Conclusions: These findings suggest that chronological age acts as a proxy variable mediating the impact of other factors such as subclinical signs of neurodegenerative disorders and that it has little independent contribution to make. They also indicate the importance of cognitive abilities supported by posterior cortical circuits in EF problem resolution. This study demonstrates that cognitive decline is not an ineluctable process that is associated with “normal” aging but rather represents, in many cases, a byproduct of neurodegenerative disorders, albeit themselves highly age-related.
This paper addresses the development of plasma polymer coatings that should prevent bacteria from adhering to medical devices, implants, textile fibers, packaging materials, etc. The two main parameters affecting bacterial colonization onto surfaces are the surface energy and the surface roughness. Both parameters can be adjusted by the deposition of a thin plasma polymer coating in an atmospheric pressure dielectric barrier glow discharge. According to SEM, FTIR, SPM, XPS and contact angle measurements, smooth, hydrophilic plasma polymer coatings were obtained under specific plasma conditions starting from 2-hydroxyethyl methacrylate (HEMA) and ethyl diazoacetate (EDA).
Individuals aged over 80 years represent the fastest growing segment of the population. It is becoming increasingly important to investigate the effect of age on cognitive functions such as language, in order to document “normal” and “abnormal” functioning. A task commonly used to test naming ability in clinical practice is the Boston Naming Test (BNT). Although norms exist for this age group, they may have limited applications because of small sample sizes on which they were derived. In addition, this test uses stimulus items that have been shown to be culturally specific. This study presents normative data for the BNT for two levels of education and two age bands based on a randomly selected Australian sample of older adults between the age of 81 and 94 years. Frequencies of the most common error types made in this group of nondemented individuals are also reported.
In running water, the main natural factor of disturbance is hydraulic. Investigation of its biological impact is currently complicated by the increase of anthropogenic disturbances which tend to mask the natural functioning of rivers. Monitoring of the impacts of the artificial alterations undergone by the Middle Rhone River for some decades took place in the mid-1980s. Discharge and temperature could constitute the major events controlling the biological dynamics in terms of variations in species richness, diversity, and abundance. The between-years changes of the structure and diversity of macroinvertebrate communities were connected with the amplitude of discharge fluctuations. This was in accordance with the disturbance-diversity concept and it seems to confirm the intermediate disturbance hypothesis. The fish community mainly depended on hydroclimatic factors that influenced breeding success. Variations in nutrient input played a secondary role in controlling changes in some communities (particularly the periphyton). Therefore it appears that the study of long-term changes in river systems, including
the dynamics of their biological communities, requires continuous observations and data collection that only medium- to long-term studies can provide, implying the setting up of ecological monitoring centres for the natural environment such as the Long Term Ecological Research (LTER) sites in United.