Search results for "sampling"

Observations of molecular hydrogen mixing ratio and stable isotopic composition at the Cabauw tall tower in the Netherlands

2016

AbstractMeasurements of the stable isotopic composition (δD(H2) or δD) of atmospheric molecular hydrogen (H2) are a useful addition to mixing ratio (χ(H2)) measurements for understanding the atmospheric H2 cycle. δD datasets published so far consist mostly of observations at background locations. We complement these with observations from the Cabauw tall tower at the CESAR site, situated in a densely populated region of the Netherlands. Our measurements show a large anthropogenic influence on the local H2 cycle, with frequently occurring pollution events that are characterized by χ(H2) values that reach up to ≈1 ppm and low δD values. An isotopic source signature analysis yields an apparent…

Data quality oriented procedure, for detailed mapping of heavy metals in urban topsoil as an approach to human health risk assessment

2021

Abstract Urban soils' health is important to the community because of the soils' potential use for recreational activities. A data quality-oriented approach to sampling design is proposed for performing soil representative surveys that gives support to defensible and statistically-based decisions. Krowoderski park in Cracow (Poland) was selected as a study case to investigate heavy metals (HMs) accumulation and to assess human risk exposure according to simulated scenarios. Statistical power was computed for optimizing the number of samples to compare HMs concentration against legal upper tolerance levels (LUTL). The samples' location was iteratively designed as random spatial distribution …

Phytoscreening as an efficient tool to delineate chlorinated solvent sources at a chlor-alkali facility

2017

Chlorinated ethenes (CE) are among the most common volatile organic compounds (VOC) that contaminate groundwater, currently representing a major source of pollution worldwide. Phytoscreening has been developed and employed through different applications at numerous sites, where it was generally useful for detection of subsurface chlorinated solvents. We aimed at delineating subsurface CE contamination at a chlor-alkali facility using tree core data that we compared with soil data. For this investigation a total of 170 trees from experimental zones was sampled and analyzed for perchloroethene (PCE) and trichloroethene (TCE) concentrations, measured by solid phase microextraction gas chromato…

Case Studies of Macro-and Microplastics Pollution in Coastal Waters and Rivers: Is There a Solution With New Removal Technologies and Policy Actions?.

2020

This opinion paper on microplastics pollution has selected different aspects and case studies of micro and macro-plastic litter pollution in coastal waters, and rivers. We point out a discussion on this topic and ask ourselves if there is a solution to the global problem by developing new microplastics removal technologies as well as policy actions. The first two case studies are related with macroplastics marine litter in beaches, a third report describes a new simple sampling device for microplastics in coastal and nearshore areas, five case study assess microplastics pollution in worldwide coastal environments, sediments and catchments (India, Mexico, Australia, Europe and the Nordic Sea…

Random forests, a novel approach for discrimination of fish populations using parasites as biological tags.

2008

Due to the complexity of host-parasite relationships, discrimination between fish populations using parasites as biological tags is difficult. This study introduces, to our knowledge for the first time, random forests (RF) as a new modelling technique in the application of parasite community data as biological markers for population assignment of fish. This novel approach is applied to a dataset with a complex structure comprising 763 parasite infracommunities in population samples of Atlantic cod, Gadus morhua, from the spawning/feeding areas in five regions in the North East Atlantic (Baltic, Celtic, Irish and North seas and Icelandic waters). The learning behaviour of RF is evaluated in …

The Impact of COVID-19 Pandemic and Lockdown Measures on Quality of Life among Italian General Population

2021

The COVID-19 pandemic that has hit the world in the year 2020 has put a strain on our ability to cope with events and revolutionized our daily habits. On 9 March, Italy was forced to lockdown to prevent the spread of the infection, with measures including the mandatory closure of schools and nonessential activities, travel restrictions, and the obligation to spend entire weeks in the same physical space. The aim of this study was to assess the impact of the COVID-19 pandemic and lockdown measures on quality of life (QoL) in a large Italian sample, in order to investigate possible differences in QoL levels related to both demographic and pandemic-specific variables. A total of 2251 Italian a…

Metabolic flux understanding of Pichia pastoris grown on heterogenous culture media

2014

[EN] Within the emergent field of Systems Biology, mathematical models obtained from physical chemical laws (the so-called first principles-based models) of microbial systems are employed to discern the principles that govern cellular behaviour and achieve a predictive understanding of cellular functions. The reliance on this biochemical knowledge has the drawback that some of the assumptions (specific kinetics of the reaction system, unknown dynamics and values of the model parameters) may not be valid for all the metabolic possible states of the network. In this uncertainty context, the combined use of fundamental knowledge and data measured in the fermentation that describe the behaviour…

FC10.06 What is a Psychiatrist? What are They Really Doing? A Qualitative Study Combining Focus Groups and Work Sampling

2000

Effective 1-day ahead prediction of hourly surface ozone concentrations in eastern Spain using linear models and neural networks

2002

The aim of this research was to develop pure predictive models in order to provide 24 h advance forecasts of the hourly ozone concentration for the rural site of Carcagente (Valencia, Spain) and the urban sites of Paterna (Valencia, Spain) and Alcoy (Alicante, Spain) over 4 years from 1996 to 1999. The peculiarity of the model presented here is that it uses past and previously predicted information of inputs exclusively, thus being this is the first genuine 24 h advance O3 predictive model with neural networks. We used autoregressive-moving average with exogenous inputs (ARMAX), multilayer perceptrons and FIR neural networks. Five performance measures yield reasonably good results in the th…

Blood pressure responsiveness to obstructive events during sleep after chronic CPAP

2003

The aim of this study was to investigate whether chronic continuous positive airway pressure (CPAP) affects blood pressure (BP) responsiveness to obstructive events occurring on the first night of CPAP withdrawal in obstructive sleep apnoea (OSA) after chronic treatment. Thirteen male subjects with severe OSA underwent nocturnal polysomnography with beat­by­beat BP monitoring before treatment and after 4.9±3.4 months of home CPAP (mean daily use 5.1±1.7 h). Variations in oxyhaemoglobin saturation (Δ S a,O2), systolic (Δ P s), and diastolic (Δ P d) BP within nonrapid eye movement apnoeas and hypopnoeas were measured on a sample of pre­ and post­treatment events. In addition, a pretreatment s…