20 research outputs found
Environmental assessment of the valorisation and recycling of selected food production side flows
Abstract Residues from the food manufacturing industry require management options with the best overall environmental outcome. The identification of sustainable solutions depends however, on many influencing factors such as energy input, transport distance, and substituted product. This study shows the influence of the choice of substituted products on the overall greenhouse gas (GHG) emissions for three specific food side-flows and their treatment in the European Union: animal blood, apple pomace and brewers' spent grain (BSG). In a direct comparison of possible treatment options, it is notable that the conversion to food ingredients (valorisation) does not always result in reduced environmental net impacts (GHG savings), which means that other options at lower levels of the waste hierarchy might be more beneficial to the environment. The further use of apple pomace or BSG for the production of food ingredients is only advantageous if the processing emissions are smaller than the emissions from the substituted products. The use of food side-flows as animal feed shows environmental advantages in all scenarios, as the use of conventional feed, such as soybean meal or hay, is reduced and so are the GHG emissions. The anaerobic digestion of food side-flows is associated with significant GHG emissions, but alternative energy also display a high GHG factor when based on fossil resources. The measuring of circularity in the food sector is a challenge in itself due to the complexity of renewable materials. This study shall help to understand the interwoven influences of certain parameters to the results
Investigation of the Young's Modulus and the Residual Stress of 4H-SiC Circular Membranes on 4H-SiC Substrates
International audienceThe stress state is a crucial parameter for the design of innovative microelectromechanical systems based on silicon carbide (SiC) material. Hence, mechanical properties of such structures highly depend on the fabrication process. Despite significant progresses in thin-film growth and fabrication process, monitoring the strain of the suspended SiC thin-films is still challenging. However, 3C-SiC membranes on silicon (Si) substrates have been demonstrated, but due to the low quality of the SiC/Si heteroepitaxy, high levels of residual strains were always observed. In order to achieve promising self-standing films with low residual stress, an alternative micromachining technique based on electrochemical etching of high quality homoepitaxy 4H-SiC layers was evaluated. This work is dedicated to the determination of their mechanical properties and more specifically, to the characterization of a 4H-SiC freestanding film with a circular shape. An inverse problem method was implemented, where experimental results obtained from bulge test are fitted with theoretical static load-deflection curves of the stressed membrane. To assess data validity, the dynamic behavior of the membrane was also investigated: Experimentally, by means of laser Doppler vibrometry (LDV) and theoretically, by means of finite element computations. The two methods provided very similar results since one obtained a Young's modulus of 410 GPa and a residual stress value of 41 MPa from bulge test against 400 GPa and 30 MPa for the LDV analysis. The determined Young's modulus is in good agreement with literature values. Moreover, residual stress values demonstrate that the fabrication of low-stressed SiC films is achievable thanks to the micromachining process developed
Unfair Trading Practice Regulation and Voluntary Agreements targeting food waste: A policy assessment in select EU Member States
This report provides a qualitative assessment of Voluntary Agreements (VAs) and Unfair Trading Practices (UTPs) as two typologies of policy interventions having an impact on food loss and waste.
To carry out this assessment, two sets of country-based comparative case studies were developed, namely in the UK and Italy for regulations against UTPs, and in the UK and the Netherlands for VAs.
The report found that, for both VAs and regulations against UTPs, a preliminary assessment of underlying food supply chain market structure is important to identify the most appropriate policy measures for a specific EU MS (e.g. the size and number of actors at each level of the food supply chain, the level of market concentration and power imbalance among actors, etc.).
Specifically concerning UTPs, the following was identified:
- Food supply chains are particularly susceptible to UTPs in MS where market power is concentrated within a few large retailers interacting with many suppliers. Perishable products, such as fresh fruits and vegetables supplied direct from primary producers to retailers are particularly at risk due to the time constraints in finding alternate outlets;
- It is important to identify solutions for food surplus generated by UTPs (ex: redistributing surplus that results from order cancellations linked to UTPs or ensuring that the \u201cwrongdoer\u201d assumes the responsibility of the food product resulting from the UTPs);
- To tackle UTPs, it was found that an effective approach would be the creation of an independent authority to investigate any infringement of good trading practices, (ex: through an industry code of practice, and, if needed, the introduction of sanctions on actors who are found to have not met the standard required by the industry code;
- Other recommendations identified include adopting a common EU-level definition of UTPs in relation to grocery supply to avoid unequal treatment of comparable situations across EU, and to allow the judgement of cases based on the principle of equity. Furthermore, indirect and foreign suppliers also need to be protected against UTPs.
Specifically concerning VAs the following was identified:
- The level and the nature of funding has a significant impact on their lifetime and agendas (a mix of public and private is optimal);
- To ensure a VA\u2019s relevance, signatories must benefit from their participating, either financially or in terms of heightened visibility;
- VAs should establish ambitious yet realistic targets, achievable by their signatories, and robustness and transparency of data reporting should be forefront to ensure the credibility of the initiatives;
- VAs can be implemented alongside compulsory legislation or provide an alternative to it. An advantage of them, compared to legislation, is that they can be designed and adapted relatively quickly depending on political goals related to food waste;
- The role of a third party is crucial in managing a VA, notably to facilitate actor accession to it, ensure confidentiality of data, supervise and eventually nudge compliance with the agreement.
The report ultimately shows that VAs and UTPs interlinked as VAs can be an effective tool to explore the effects of regulation against UTPs and assess actors\u2019 readiness to avoid market power abuse
Aberrant subcutaneous adipogenesis precedes adult metabolic dysfunction in an ovine model of polycystic ovary syndrome (PCOS)
Polycystic ovary syndrome (PCOS) affects over 10% of women. Insulin resistance, elevated free fatty acids (FFAs) and increased adiposity are key factors contributing to metabolic dysfunction in PCOS. We hypothesised that aberrant adipogenesis during adolescence, and downstream metabolic perturbations, contributes to the metabolic phenotype of adult PCOS. We used prenatally androgenized (PA) sheep as a clinically realistic model of PCOS. During adolescence, but not during fetal or early life of PA sheep, adipogenesis was decreased in subcutaneous adipose tissue (SAT) accompanied by decreased leptin, adiponectin, and increased FFAs. In adulthood, PA sheep developed adipocyte hypertrophy in SAT paralleled by increased expression of inflammatory markers, elevated FFAs and increased expression of genes linked to fat accumulation in visceral adipose tissue. This study provides better understanding into the pathophysiology of PCOS from puberty to adulthood and identifies opportunity for early clinical intervention to normalise adipogenesis and ameliorate the metabolic phenotype
Exocomets from a Solar System Perspective
Exocomets are small bodies releasing gas and dust which orbit stars other
than the Sun. Their existence was first inferred from the detection of variable
absorption features in stellar spectra in the late 1980s using spectroscopy.
More recently, they have been detected through photometric transits from space,
and through far-IR/mm gas emission within debris disks. As (exo)comets are
considered to contain the most pristine material accessible in stellar systems,
they hold the potential to give us information about early stage formation and
evolution conditions of extra Solar Systems. In the Solar System, comets carry
the physical and chemical memory of the protoplanetary disk environment where
they formed, providing relevant information on processes in the primordial
solar nebula. The aim of this paper is to compare essential compositional
properties between Solar System comets and exocomets. The paper aims to
highlight commonalities and to discuss differences which may aid the
communication between the involved research communities and perhaps also avoid
misconceptions. Exocomets likely vary in their composition depending on their
formation environment like Solar System comets do, and since exocomets are not
resolved spatially, they pose a challenge when comparing them to high fidelity
observations of Solar System comets. Observations of gas around main sequence
stars, spectroscopic observations of "polluted" white dwarf atmospheres and
spectroscopic observations of transiting exocomets suggest that exocomets may
show compositional similarities with Solar System comets. The recent
interstellar visitor 2I/Borisov showed gas, dust and nuclear properties similar
to that of Solar System comets. This raises the tantalising prospect that
observations of interstellar comets may help bridge the fields of exocomet and
Solar System comets.Comment: 25 pages, 3 figures. To be published in PASP. This paper is the
product of a workshop at the Lorentz Centre in Leiden, the Netherland
COVID-19 trajectories among 57 million adults in England: a cohort study using electronic health records
BACKGROUND:
Updatable estimates of COVID-19 onset, progression, and trajectories underpin pandemic mitigation efforts. To identify and characterise disease trajectories, we aimed to define and validate ten COVID-19 phenotypes from nationwide linked electronic health records (EHR) using an extensible framework.
METHODS:
In this cohort study, we used eight linked National Health Service (NHS) datasets for people in England alive on Jan 23, 2020. Data on COVID-19 testing, vaccination, primary and secondary care records, and death registrations were collected until Nov 30, 2021. We defined ten COVID-19 phenotypes reflecting clinically relevant stages of disease severity and encompassing five categories: positive SARS-CoV-2 test, primary care diagnosis, hospital admission, ventilation modality (four phenotypes), and death (three phenotypes). We constructed patient trajectories illustrating transition frequency and duration between phenotypes. Analyses were stratified by pandemic waves and vaccination status.
FINDINGS:
Among 57â032â174 individuals included in the cohort, 13â990â423 COVID-19 events were identified in 7â244â925 individuals, equating to an infection rate of 12·7% during the study period. Of 7â244â925 individuals, 460â737 (6·4%) were admitted to hospital and 158â020 (2·2%) died. Of 460â737 individuals who were admitted to hospital, 48â847 (10·6%) were admitted to the intensive care unit (ICU), 69â090 (15·0%) received non-invasive ventilation, and 25â928 (5·6%) received invasive ventilation. Among 384â135 patients who were admitted to hospital but did not require ventilation, mortality was higher in wave 1 (23â485 [30·4%] of 77â202 patients) than wave 2 (44â220 [23·1%] of 191â528 patients), but remained unchanged for patients admitted to the ICU. Mortality was highest among patients who received ventilatory support outside of the ICU in wave 1 (2569 [50·7%] of 5063 patients). 15â486 (9·8%) of 158â020 COVID-19-related deaths occurred within 28 days of the first COVID-19 event without a COVID-19 diagnoses on the death certificate. 10â884 (6·9%) of 158â020 deaths were identified exclusively from mortality data with no previous COVID-19 phenotype recorded. We observed longer patient trajectories in wave 2 than wave 1.
INTERPRETATION:
Our analyses illustrate the wide spectrum of disease trajectories as shown by differences in incidence, survival, and clinical pathways. We have provided a modular analytical framework that can be used to monitor the impact of the pandemic and generate evidence of clinical and policy relevance using multiple EHR sources.
FUNDING:
British Heart Foundation Data Science Centre, led by Health Data Research UK
Sonde Hybride Bi-FrĂ©quence -Ămission cMUT/RĂ©ception P(VDF- TrFE)- pour lâImagerie Harmonique
Lâimagerie harmonique est aujourdâhui un standard en pratique clinique. Elle consiste Ă Ă©mettre des ultrasons Ă une frĂ©quence f<sub>0</sub> et de les recevoir Ă 2f<sub>0</sub>. De plus, lâutilisation de microbulles (agents de contraste) permet dâobtenir des images Ă©chographiques avec un contraste amĂ©liorĂ© et lâimagerie super-harmonique dâexploiter en rĂ©ception des harmoniques jusquâĂ 7f<sub>0</sub> pour des applications haute-rĂ©solution comme lâangiographie. Dans ce cas, lâĂ©cart de frĂ©quence entre lâĂ©mission et la rĂ©ception ne permet plus dâeffectuer correctement ces deux fonctions en utilisant un seul et mĂȘme transducteur. Le choix de combiner deux technologies de sondes ultrasonores pour rĂ©pondre Ă cette problĂ©matique peut ĂȘtre une solution : le P(VDF-TrFE) est un copolymĂšre piĂ©zoĂ©lectrique sensible en rĂ©ception sur une trĂšs large gamme de frĂ©quences. NĂ©anmoins, son manque de puissance Ă lâĂ©mission nĂ©cessite dâutiliser une autre technologie comme un cMUT. Sa bande passante est moindre mais reste gĂ©nĂ©ralement supĂ©rieure Ă celle dâun transducteur intĂ©grant un matĂ©riau piĂ©zoĂ©lectrique classique. PremiĂšrement, les transducteurs sont Ă©tudiĂ©s sĂ©parĂ©ment. Le champ de pression de la barrette de 128 Ă©lĂ©ments de cMUT (f<sub>c</sub>=7MHz) est mesurĂ© afin de sâassurer que le volume insonifiĂ© est supĂ©rieur Ă la taille dâune tumeur de 4mm<sup>3</sup> avec une pression nĂ©gative minimale de 300kPa Ă 1,7cm pour obtenir un index mĂ©canique supĂ©rieur Ă 0,3 pour lâexcitation des microbulles. La barrette est caractĂ©risĂ©e sur sa bande de frĂ©quence 5-10MHz pour sâadresser Ă diffĂ©rentes familles de microbulles. La barrette Ă base de P(VDF-TrFE) constituĂ©e de 32 Ă©lĂ©ments est caractĂ©risĂ©e en rĂ©ception sur la gamme 5-40MHz. Un banc in-vitro est rĂ©alisĂ© et utilisĂ© avec des bulles MicroVevo Markerâą afin dâobtenir une image en utilisant des formations de faisceau standard (ici, compounding) mais adaptĂ©es Ă la configuration de la sonde unifiĂ©e. Les rĂ©sultats montrent clairement lâintĂ©rĂȘt de ce dispositif pour amĂ©liorer la rĂ©solution de lâimage obtenue