1,299 research outputs found
Waste prevention and education in five european countries
Artigo desenvolvido no Ăąmbito de uma Unidade Curricular que funcionou em rede entre vĂĄrias Universidades Europeias. Este artigo foi desenvolvido num trabalho em rede desenvolvido entre estudantes de diversas universidade e que avaliaram a implementação da diretiva quadro de resĂduos em diversos paĂses da UniĂŁo Europeia e apresentarem um conjunto de recomendaçÔes para se uniformizar e melhorar a gestĂŁo de resĂduos na Europa com a aplicação da hierarquia dos resĂduos.This research assessed the different goals of the EU Waste Framework Directive (2008) concerning waste prevention in five countries of the EU. The countries under research are the home countries of the EVS group members: Austria, Belgium, Germany, Netherlands and Portugal. The research about the status quo of waste prevention revealed that waste preven-tion has not reached yet. All the countries have high recycling rates and low dumping rate, ex-cept Portugal. Although decoupling trends start to appear and the countries are climbing up the waste hierarchy, waste prevention is still a mountain too far. The EVS group also checked if education was included in the waste prevention programmes and education plays a very im-portant role. The group looked for good examples of waste prevention and analyzed them with SWOT. The examples are a success in the home countries and can be implemented in other EU or even worldwide countries.info:eu-repo/semantics/publishedVersio
Translation-invariance of two-dimensional Gibbsian point processes
The conservation of translation as a symmetry in two-dimensional systems with
interaction is a classical subject of statistical mechanics. Here we establish
such a result for Gibbsian particle systems with two-body interaction, where
the interesting cases of singular, hard-core and discontinuous interaction are
included. We start with the special case of pure hard core repulsion in order
to show how to treat hard cores in general.Comment: 44 pages, 6 figure
Content in fatty acids and carotenoids in phytoplankton blooms during the seasonal sea ice retreat in Hudson Bay complex, Canada.
The Hudson Bay complex (HBC) is home to numerous indigenous communities that traditionally have relied
heavily on its marine resources. The nutritional quality and stocks of the entire HBC food web depend in
large part on the phytoplankton production of bioactive molecules (long chain polyunsaturated fatty acids
and carotenoids) and their transfer through trophic levels. The purpose of this study was thus to
determine which molecules were produced during spring phytoplankton blooms, as well as the
environmental factors driving this production. We investigated 21 stations in 5 sub-regions of the HBC.
At the time of sampling, the sub-regions studied had different environmental settings (e.g., ice cover,
nutrients, seawater salinity and temperature) conditioning their bloom stages. Pre- and post-bloom stages
were associated with relatively low concentrations of bioactive molecules (either fatty acids or
carotenoids). In contrast, the highest concentrations of bioactive molecules (dominated by
eicosapentaenoic acid and fucoxanthin) were associated with the diatom bloom that typically occurs at
the ice edge when silicates remain available. Interestingly, the large riverine inputs in eastern Hudson Bay
led to a change in protist composition (larger contribution of Dinophyceae), resulting in lower while more
diverse content of bioactive molecules, whether fatty acids (e.g., aa-linolenic acid) or carotenoids
(e.g., peridinin). As greater stratification of the HBC is expected in the future, we suggest that
a mixotrophic/heterotrophic flagellate-based food web would become more prevalent, resulting in
a smaller supply of bioactive molecules for the food web
Constructing solutions to the Bj\"orling problem for isothermic surfaces by structure preserving discretization
In this article, we study an analog of the Bj\"orling problem for isothermic
surfaces (that are more general than minimal surfaces): given a real analytic
curve in , and two analytic non-vanishing orthogonal
vector fields and along , find an isothermic surface that is
tangent to and that has and as principal directions of
curvature. We prove that solutions to that problem can be obtained by
constructing a family of discrete isothermic surfaces (in the sense of Bobenko
and Pinkall) from data that is sampled along , and passing to the limit
of vanishing mesh size. The proof relies on a rephrasing of the
Gauss-Codazzi-system as analytic Cauchy problem and an in-depth-analysis of its
discretization which is induced from the geometry of discrete isothermic
surfaces. The discrete-to-continuous limit is carried out for the Christoffel
and the Darboux transformations as well.Comment: 29 pages, some figure
Addition of platinum derivatives to neoadjuvant single-agent fluoropyrimidine chemoradiotherapy in patients with stage II/III rectal cancer: protocol for a systematic review and meta-analysis (PROSPERO CRD42017073064)
Background Neoadjuvant (chemo-)radiation has proven to improve local control compared to surgery alone, but this improvement did not translate into better overall or disease-specific survival. The addition of oxaliplatin to fluoropyrimidine-based neoadjuvant chemoradiotherapy holds the potential of positively affecting survival in this context since it has been proven effective in the palliative and adjuvant setting of colorectal cancer. Thus, the objective of this systematic review is to assess the efficacy, safety, and quality of life resulting from adding a platinum derivative to neoadjuvant single-agent fluoropyrimidine-based chemoradiotherapy in patients with Union for International Cancer Control stage II and III rectal cancer.
Methods: MEDLINE, Web of Science, and Cochrane Central Register of Controlled Trials will be systematically searched to identify all randomized controlled trials comparing single-agent fluoropyrimidine-based chemoradiotherapy to combined neoadjuvant therapy including a platinum derivative. Predefined data on trial design, quality, patient characteristics, and endpoints will be extracted. Quality of included trials will be assessed according to the Cochrane Risk of Bias Tool, and the GRADE recommendations will be applied to judge the quality of the resulting evidence. The main outcome parameter will be survival, but also treatment toxicity, perioperative morbidity, and quality of life will be assessed.
Discussion: The findings of this systematic review and meta-analysis will provide novel insights into the efficacy and safety of combined neoadjuvant chemoradiotherapy including a platinum derivative and may form a basis for future clinical decision-making, guideline evaluation, and research prioritization. Systematic review registration PROSPERO CRD4201707306
The influence of spectral solar irradiance data on stratospheric heating rates during the 11 year solar cycle
Heating rate calculations with the FUBRad shortwave (SW) radiation parameterization have been performed to examine the effect of prescribed spectral solar fluxes from the NRLSSI, MPS and IUP data sets on SW heating rates over the 11 year solar cycle 22. The corresponding temperature response is derived from perpetual January General Circulation Model (GCM) simulations with prescribed ozone concentrations. The different solar flux input data sets induce clear differences in SW heating rates at solar minimum, with the established NRLSSI data set showing the smallest solar heating rates. The stronger SW heating in the middle and upper stratosphere in the MPS data warms the summer upper stratosphere by 2 K. Over the solar cycle, SW heating rate differences vary up to 40% between the irradiance data sets, but do not result in a significant change of the solar temperature signal. Lower solar fluxes in the newer SIM data lead to a significantly cooler stratosphere and mesosphere when compared to NRLSSI data for 2007. Changes in SW heating from 2004 to 2007 are however up to six times stronger than for the NRLSSI data.
Key Points:
- Solar minimum and solar cycle differences in SW heating rates and temperature
- Comparison of three spectral solar input data sets for solar cycle 22
- Comparison of the newly compiled SORCE-data with the commonly used NRLSSI-dat
Formation of Structure in Snowfields: Penitentes, Suncups, and Dirt Cones
Penitentes and suncups are structures formed as snow melts, typically high in
the mountains. When the snow is dirty, dirt cones and other structures can form
instead. Building on previous field observations and experiments, this work
presents a theory of ablation morphologies, and the role of surface dirt in
determining the structures formed. The glaciological literature indicates that
sunlight, heating from air, and dirt all play a role in the formation of
structure on an ablating snow surface. The present work formulates a
mathematical model for the formation of ablation morphologies as a function of
measurable parameters. The dependence of ablation morphologies on weather
conditions and initial dirt thickness are studied, focusing on the initial
growth of perturbations away from a flat surface. We derive a single-parameter
expression for the melting rate as a function of dirt thickness, which agrees
well with a set of measurements by Driedger. An interesting result is the
prediction of a dirt-induced travelling instability for a range of parameters.Comment: 28 pages, 13 figure
Conditional Intensity and Gibbsianness of Determinantal Point Processes
The Papangelou intensities of determinantal (or fermion) point processes are
investigated. These exhibit a monotonicity property expressing the repulsive
nature of the interaction, and satisfy a bound implying stochastic domination
by a Poisson point process. We also show that determinantal point processes
satisfy the so-called condition which is a general form of
Gibbsianness. Under a continuity assumption, the Gibbsian conditional
probabilities can be identified explicitly.Comment: revised and extende
Environmental drivers of spring primary production in Hudson Bay
Pertinent environmental factors influencing the microalgal bloom during sea-ice breakup in Hudson Bay were
investigated in June 2018, producing the first observations of late spring primary production in the offshore
waters of this vast inland sea. Phytoplankton production was found to commence at the onset of ice melt,
with surface nutrient depletion leading to the formation of a subsurface chlorophyll maximum in the open
waters of western Hudson Bay. Concurrently, the melting mobile ice cover in central Hudson Bay created
favorable conditions for a diatom-dominated under-ice bloom, with photosynthetic characteristics and
relatively high production confirming that phytoplankton cells were able to acclimate to increasing light
levels. Lower mean values of phytoplankton production and total chlorophyll a (TChl a) concentration
observed under the sea ice (414 mg C mâ2 dâ1 and 33.7 mg TChl a mâ2) than those observed in open waters
during the late bloom stage in the western region (460 mg C mâ2 dâ1 and 53.5 mgTChl a mâ2) were attributed to
reduced under-ice light levels and low surface concentrations of dissolved inorganic nitrogen (<2 mmol Lâ1) in
central Hudson Bay. However, the highly abundant subice diatom, Melosira arctica, was estimated to
contribute an additional 378 mg C mâ2 dâ1 to under-ice production in this region. Therefore, this subice
algal bloom appears to play a similar role in the seasonally ice-covered sub-Arctic as in the central Arctic
Ocean where it contributes significantly to local production. By updating historical total production
estimates of Hudson Bay ranging between 21.5 and 39 g C mâ2 yrâ1 with our late spring observations
including the novel observation of M. arctica, annual production was recalculated to be 72 g C mâ2 yrâ1,
which equates to mean values for interior Arctic shelves
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