Spatial and temporal specificity of Ca2+signalling inChlamydomonas reinhardtiiin response to osmotic stress

Ca2+-dependent signalling processes enable plants to perceive and respond to diverse environmental stressors, such as osmotic stress. A clear understanding of the role of spatiotemporal Ca2+ signalling in green algal lineages is necessary in order to understand how the Ca2+ signalling machinery has evolved in land plants. We used single-cell imaging of Ca2+-responsive fluorescent dyes in the unicellular green alga Chlamydomonas reinhardtii to examine the specificity of spatial and temporal dynamics of Ca2+ elevations in the cytosol and flagella in response to salinity and osmotic stress. We found that salt stress induced a single Ca2+ elevation that was modulated by the strength of the stimulus and originated in the apex of the cell, spreading as a fast Ca2+ wave. By contrast, hypo-osmotic stress induced a series of repetitive Ca2+ elevations in the cytosol that were spatially uniform. Hypo-osmotic stimuli also induced Ca2+ elevations in the flagella that occurred independently from those in the cytosol. Our results indicate that the requirement for Ca2+ signalling in response to osmotic stress is conserved between land plants and green algae, but the distinct spatial and temporal dynamics of osmotic Ca2+ elevations in C. reinhardtii suggest important mechanistic differences between the two lineages.

Spatial and temporal specificity of Ca2+signalling inChlamydomonas reinhardtiiin response to osmotic stress

Ca2+-dependent signalling processes enable plants to perceive and respond to diverse environmental stressors, such as osmotic stress. A clear understanding of the role of spatiotemporal Ca2+ signalling in green algal lineages is necessary in order to understand how the Ca2+ signalling machinery has evolved in land plants. We used single-cell imaging of Ca2+-responsive fluorescent dyes in the unicellular green alga Chlamydomonas reinhardtii to examine the specificity of spatial and temporal dynamics of Ca2+ elevations in the cytosol and flagella in response to salinity and osmotic stress. We found that salt stress induced a single Ca2+ elevation that was modulated by the strength of the stimulus and originated in the apex of the cell, spreading as a fast Ca2+ wave. By contrast, hypo-osmotic stress induced a series of repetitive Ca2+ elevations in the cytosol that were spatially uniform. Hypo-osmotic stimuli also induced Ca2+ elevations in the flagella that occurred independently from those in the cytosol. Our results indicate that the requirement for Ca2+ signalling in response to osmotic stress is conserved between land plants and green algae, but the distinct spatial and temporal dynamics of osmotic Ca2+ elevations in C. reinhardtii suggest important mechanistic differences between the two lineages.

Spatial and Temporal Variations in Airborne Ambrosia Pollen in Europe

Aim: The European Commission Cooperation in Science and Technology (COST) Action FA1203 “SMARTER” aims to make recommendations for the sustainable management of Ambrosia across Europe and for monitoring its efficiency and cost effectiveness. The goal of the present study is to provide a baseline for spatial and temporal variations in airborne Ambrosia pollen in Europe that can be used for the management and evaluation of this noxious plant . Location: The full range of Ambrosia artemisiifolia L. distribution over Europe (39oN-60oN; 2oW-45oE). Methods: Airborne Ambrosia pollen data for the principal flowering period of Ambrosia (August-September) recorded during a 10-year period (2004-2013) were obtained from 242 monitoring sites. The mean sum of daily average airborne Ambrosia pollen and the number of days that Ambrosia pollen was recorded in the air were analysed. The mean and Standard Deviation (SD) were calculated regardless of the number of years included in the study period, while trends are based on those time series with 8 or more years of data. Trends were considered significant at p < 0.05. Results: There were few significant trends in the magnitude and frequency of atmospheric Ambrosia pollen (only 8% for the mean sum of daily average Ambrosia pollen concentrations and 14% for the mean number of days Ambrosia pollen was recorded in the air). Main conclusions: The direction of any trends varied locally and reflect changes in sources of the pollen, either in size or in distance from the monitoring station. Pollen monitoring is important for providing an early warning of the expansion of this invasive and noxious plant.

Spatial and Temporal Dynamics of Larval Atlantic Menhaden on the East Coast of the United States

Atlantic Menhaden Brevoortia tyrannus is a commercially and ecologically important forage fish abundant on the Atlantic Coast of the United States. We conducted spatial and temporal analyses of larval Atlantic Menhaden using data collected from two large-scale ichthyoplankton programs during 1977-1987 and 1999-2013 to construct indices of larval abundance and survival over time, evaluate how environmental factors affect early life survival, and examine how larvae are distributed in space to gain knowledge on spawning and larval dispersal. Over time, we found larval abundance to increase, while early life survival declined. Coastal temperature, wind speed, and Atlantic Multidecadal Oscillation were found to potentially explain some of this decline in survival. Over both periods, we found evidence spawning predominantly occurs near shore, from New York to North Carolina, increasing in intensity southwards. While the general spatial patterns were consistent, we observed some localized variation and overall expansion of occupied area by larvae.

Spatial and temporal interaction between sediment and microphytobenthos in a temperate estuarine macro-intertidal bay

Intertidal flats of the estuarine macro-intertidal Baie des Veys (France) were investigated to identify spatial features of sediment and microphytobenthos (MPB) in April 2003. Gradients occurred within the domain, and patches were identified close to vegetated areas or within the oyster-farming areas where calm physical conditions and biodeposition altered the sediment and MPB landscapes. Spatial patterns of chl a content were explained primarily by the influence of sediment features, while bed elevation and compaction brought only minor insights into MPB distribution regulation. The smaller size of MPB patches compared to silt patches revealed the interplay between physical structure defining the sediment landscape, the biotic patches that they contain, and that median grain-size is the most important parameter in explaining the spatial pattern of MPB. Small-scale temporal dynamics of sediment chl a content and grain-size distribution were surveyed in parallel during 2 periods of 14 d to detect tidal and seasonal variations. Our results showed a weak relationship between mud fraction and MPB biomass in March, and this relationship fully disappeared in July. Tidal exposure was the most important parameter in explaining the summer temporal dynamics of MPB. This study reveals the general importance of bed elevation and tidal exposure in muddy habitats and that silt content was a prime governing physical factor in winter. Biostabilisation processes seemed to behave only as secondary factors that could only amplify the initial silt accumulation in summer rather than primary factors explaining spatial or long-term trends of sediment changes.

Spatial and temporal measurements using polyoxometalate, enzymatic and biofilm layers on a CMOS 0.35 μm 64 X 64-pixel I.S.F.E.T. array sensor

This thesis presents the achievements and scientific work conducted using a previously designed and fabricated 64 x 64-pixel ion camera with the use of a 0.35 μm CMOS technology. We used an array of Ion Sensitive Field Effect Transistors (ISFETs) to monitor and measure chemical and biochemical reactions in real time. The area of our observation was a 4.2 x 4.3 mm silicon chip while the actual ISFET array covered an area of 715.8 x 715.8 μm consisting of 4096 ISFET pixels in total with a 1 μm separation space among them. The ion sensitive layer, the locus where all reactions took place was a silicon nitride layer, the final top layer of the austriamicrosystems 0.35 μm CMOS technology used. Our final measurements presented an average sensitivity of 30 mV/pH. With the addition of extra layers we were able to monitor a 65 mV voltage difference during our experiments with glucose and hexokinase, whereas a difference of 85 mV was detected for a similar glucose reaction mentioned in literature, and a 55 mV voltage difference while performing photosynthesis experiments with a biofilm made from cyanobacteria, whereas a voltage difference of 33.7 mV was detected as presented in literature for a similar cyanobacterial species using voltamemtric methods for detection. To monitor our experiments PXIe-6358 measurement cards were used and measurements were controlled by LabVIEW software. The chip was packaged and encapsulated using a PGA-100 chip carrier and a two-component commercial epoxy. Printed circuit board (PCB) has also been previously designed to provide interface between the chip and the measurement cards.

Determination of biodiversity and spatial and temporal distribution pattern of demersal fishes in the Oman Sea

In this project, have been studied to determine the appropriate model to spatial, temporal and diversity of demersal fishes in the Sea of Oman, including Trichiuridae, Nemipteridae, Haemulidae, Arridae, Synodontidae, Batoidfishes, Carangidae, Scianidae, Carchariniformes and Serranidae. This research became operational from catch data during 2003 to 2013 (in 2007, due to the lack of ship failed). Processing and calculations was evaluated by using the software Excel, SPSS, Arc GIS and table curve 3D highest biomass and abundance was showed in strata A and C and 10-30 m depth layers was showed the best condition biomass. In other words, highest biomass was showed in the eastern region in the Oman Sea than the central and western regions. Batoidfishes and Trichiuridae had the highest biomass .Depth factors was showed a significant correlation with the biomass. Scianidae, Serranidae and Haemulidae were showed a large decline. Synodontidae was showed a very large increase. The largest of Shannon index belong to central and western region of the Oman Sea. The highest Shannon index was showed 10-20 and 50-100 m, respectively. The Distribution maps based on the biomass was analyzed by using Arc GIS software. So that were identified in the first time in a ten-year period and carefully catch stations any economic of aquatic group. In conclusion, the depth can be found in the pattern of distribution, abundance and diversity of fish from away the beach so that follow specific pattern.

Development of nanostructured hydrogel for spatial and temporal controlled release of active compounds

L’utilisation de nanovecteurs pour la livraison contrôlée de principes actifs est un concept commun de nous jours. Les systèmes de livraison actuels présentent encore cependant des limites au niveau du taux de relargage des principes actifs ainsi que de la stabilité des transporteurs. Les systèmes composés à la fois de nanovecteurs (liposomes, microgels et nanogels) et d’hydrogels peuvent cependant permettre de résoudre ces problèmes. Dans cette étude, nous avons développé un système de livraison contrôlé se basant sur l’incorporation d’un nanovecteur dans une matrice hydrogel dans le but de combler les lacunes des systèmes se basant sur un vecteur uniquement. Une telle combinaison pourrait permettre un contrôle accru du relargage par stabilisation réciproque. Plus spécifiquement, nous avons développé un hydrogel structuré intégrant des liposomes, microgels et nanogels séparément chargés en principes actifs modèles potentiellement relargués de manière contrôlé. Ce contrôle a été obtenu par la modification de différents paramètres tels que la température ainsi que la composition et la concentration en nanovecteurs. Nous avons comparé la capacité de chargement et la cinétique de relargage de la sulforhodamine B et de la rhodamine 6G en utilisant des liposomes de DOPC et DPPC à différents ratios, des nanogels de chitosan/acide hyaluronique et des microgels de N-isopropylacrylamide (NIPAM) à différents ratios d’acide méthacrylique, incorporés dans un hydrogel modèle d’acrylamide. Les liposomes présentaient des capacités de chargement modérés avec un relargage prolongé sur plus de dix jours alors que les nanogels présentaient des capacités de chargement plus élevées mais une cinétique de relargage plus rapide avec un épuisement de la cargaison en deux jours. Comparativement, les microgels relarguaient complétement leur contenu en un jour. Malgré une cinétique de relargage plus rapide, les microgels ont démontré la possibilité de contrôler finement le chargement en principe actif. Ce contrôle peut être atteint par la modification des propriétés structurelles ou en changeant le milieu d’incubation, comme l’a montré la corrélation avec les isothermes de Langmuir. Chaque système développé a démontré un potentiel contrôle du taux de relargage, ce qui en fait des candidats pour des investigations futures.

Effects of a rhythmic and choreographic program in obese and overweight participants

Introduction: Currently there is a growing trend in the prevalence of overweight and obesity. This increased prevalence trend leads to an increase in the costs of health care. Objective: The aim of the present study was to analyze the effects on physical fitness and bone mineral density through an intervention program of physical activity based on rhythmic and choreographic activities in an overweight and obese population. Method: An 8-month physical activity based on rhythmic and choreographic activities was conducted in overweight and obese people. Thirty-four participants aged 50.43 ± 10.57 with a body mass index (BMI) 38.37 ± 4.82 took part in the physical activity program. This study assesses the effects of fitness, percentage of body fat and bone mineral density (BMD). Results: After an 8-month physical activity intervention program based on rhythmic and choreographic activities, significant differences were found in: percentage of body fat (p = 0.004), aerobic capacity (p = 0.023), flexibility of the lower limbs (flexibility in the right leg p = 0.029 and left leg p = 0.002), balance (p < 0.001), strength in lower limbs (p = 0..003) and strength in upper limbs (p < 0.001). Besides that, significant differences were found in parameters related with BMD such as T-Score (p = 0.025) and Z-Score (p = 0.012), Bone Quality Index (BQI) (p = 0.026) and an increase in Broadband Ultrasound Attenuation (BUA) although not a statistically significant one (p = 0.939). Conclusions: These findings suggest that a physical activity program based on rhythmic and choreographic activities can act as a preventive method of mobility and fragility, as well as preventing bone loss.

Motion Planning and Controls with Safety and Temporal Constraints

Motion planning, or trajectory planning, commonly refers to a process of converting high-level task specifications into low-level control commands that can be executed on the system of interest. For different applications, the system will be different. It can be an autonomous vehicle, an Unmanned Aerial Vehicle(UAV), a humanoid robot, or an industrial robotic arm. As human machine interaction is essential in many of these systems, safety is fundamental and crucial. Many of the applications also involve performing a task in an optimal manner within a given time constraint. Therefore, in this thesis, we focus on two aspects of the motion planning problem. One is the verification and synthesis of the safe controls for autonomous ground and air vehicles in collision avoidance scenarios. The other part focuses on the high-level planning for the autonomous vehicles with the timed temporal constraints. In the first aspect of our work, we first propose a verification method to prove the safety and robustness of a path planner and the path following controls based on reachable sets. We demonstrate the method on quadrotor and automobile applications. Secondly, we propose a reachable set based collision avoidance algorithm for UAVs. Instead of the traditional approaches of collision avoidance between trajectories, we propose a collision avoidance scheme based on reachable sets and tubes. We then formulate the problem as a convex optimization problem seeking control set design for the aircraft to avoid collision. We apply our approach to collision avoidance scenarios of quadrotors and fixed-wing aircraft. In the second aspect of our work, we address the high level planning problems with timed temporal logic constraints. Firstly, we present an optimization based method for path planning of a mobile robot subject to timed temporal constraints, in a dynamic environment. Temporal logic (TL) can address very complex task specifications such as safety, coverage, motion sequencing etc. We use metric temporal logic (MTL) to encode the task specifications with timing constraints. We then translate the MTL formulae into mixed integer linear constraints and solve the associated optimization problem using a mixed integer linear program solver. We have applied our approach on several case studies in complex dynamical environments subjected to timed temporal specifications. Secondly, we also present a timed automaton based method for planning under the given timed temporal logic specifications. We use metric interval temporal logic (MITL), a member of the MTL family, to represent the task specification, and provide a constructive way to generate a timed automaton and methods to look for accepting runs on the automaton to find an optimal motion (or path) sequence for the robot to complete the task.

Spatial and Temporal Patterns in the Distribution, Behavior, and Activity of Fishes in Canals of the Everglades

Landscape characteristics, disturbances, and temporal variability influence predator-prey relationships, but are often overlooked in experimental studies. In the Everglades, seasonal disturbances force the spatial overlap of predators and prey, potentially increasing predation risk for prey. This study examined seasonal and diel patterns of fish use of canals and assessed predation risk for small fishes using an encounter rate model. I deployed an imaging sonar in Everglades canals to quantify density and swimming speeds of fishes, and detect anti-predator behaviors by small fishes. Generally, seasonal declines of marsh water-levels increased the density of large fishes in canals. Densities of small and large fishes were positively correlated and, as small-fish density increased, schooling frequency also increased. At night, schools disbanded and small fishes were observed congregating along the canal edge. The encounter rate model predicted highest predator-prey encounters during the day, but access to cover may reduce predation risk for small fishes.

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease.

Hilbert Space Valued Signal Plus Noise Models: Analysis of Structural Breaks under High Dimensionality and Temporal Dependence

This thesis is concerned with change point analysis for time series, i.e. with detection of structural breaks in time-ordered, random data. This long-standing research field regained popularity over the last few years and is still undergoing, as statistical analysis in general, a transformation to high-dimensional problems. We focus on the fundamental »change in the mean« problem and provide extensions of the classical non-parametric Darling-Erdős-type cumulative sum (CUSUM) testing and estimation theory within highdimensional Hilbert space settings. In the first part we contribute to (long run) principal component based testing methods for Hilbert space valued time series under a rather broad (abrupt, epidemic, gradual, multiple) change setting and under dependence. For the dependence structure we consider either traditional m-dependence assumptions or more recently developed m-approximability conditions which cover, e.g., MA, AR and ARCH models. We derive Gumbel and Brownian bridge type approximations of the distribution of the test statistic under the null hypothesis of no change and consistency conditions under the alternative. A new formulation of the test statistic using projections on subspaces allows us to simplify the standard proof techniques and to weaken common assumptions on the covariance structure. Furthermore, we propose to adjust the principal components by an implicit estimation of a (possible) change direction. This approach adds flexibility to projection based methods, weakens typical technical conditions and provides better consistency properties under the alternative. In the second part we contribute to estimation methods for common changes in the means of panels of Hilbert space valued time series. We analyze weighted CUSUM estimates within a recently proposed »high-dimensional low sample size (HDLSS)« framework, where the sample size is fixed but the number of panels increases. We derive sharp conditions on »pointwise asymptotic accuracy« or »uniform asymptotic accuracy« of those estimates in terms of the weighting function. Particularly, we prove that a covariance-based correction of Darling-Erdős-type CUSUM estimates is required to guarantee uniform asymptotic accuracy under moderate dependence conditions within panels and that these conditions are fulfilled, e.g., by any MA(1) time series. As a counterexample we show that for AR(1) time series, close to the non-stationary case, the dependence is too strong and uniform asymptotic accuracy cannot be ensured. Finally, we conduct simulations to demonstrate that our results are practically applicable and that our methodological suggestions are advantageous.