52 research outputs found
Duurzaamheid van ethanolbieten : het toetsingskader toegepast
In deze studie is een poging gedaan om in een concrete bio-energieketen en aan de hand van concrete datasets, het toetsingskader toe te passen waar mogelijk. Gekozen is voor ethanolproductie op basis van suikerbieten waarbij het accent is gelegd op het agronomische deel van de keten. De duurzaamheid van de suikerbietethanolketen, zoals hier berekend, scoort goed op de criteria die in ogenschouw zijn genomen. De reductie van broeikasgasemissie voldoet aan de norm van 30%. Een intensievere teelt van suikerbieten heeft geen betekenisvolle invloed op de C-voorraad in de bodem noch op het milieu. De energiebalans is positief, met een netto-energieopbrengst van gemiddeld 76 GJ per ha gedurende 3 jaren op 2 proefbedrijven in Nederland. Hierbij moet worden opgemerkt dat relatief gunstige aannames zijn gebruikt. Indien minder optimistische waarden zouden worden gebruikt, liggen de resultaten minder gunstig maar nog steeds voldoende positief. Er is echter wel sprake van veel onzekerheden. Met name de berekeningen van de lachgasemissie, N-mineralisatie en parameters voor de bodem organische stof vragen een betere onderbouwing
Twisting of the zebrafish heart tube during cardiac looping is a tbx5-dependent and tissue-intrinsic process
Organ laterality refers to the left-right asymmetry in disposition and conformation of internal organs and is established during embryogenesis. The heart is the first organ to display visible left-right asymmetries through its left-sided positioning and rightward looping. Here, we present a new zebrafish loss-of-function allele for tbx5a, which displays defective rightward cardiac looping morphogenesis. By mapping individual cardiomyocyte behavior during cardiac looping, we establish that ventricular and atrial cardiomyocytes rearrange in distinct directions. As a consequence, the cardiac chambers twist around the atrioventricular canal resulting in torsion of the heart tube, which is compromised in tbx5a mutants. Pharmacological treatment and ex vivo culture establishes that the cardiac twisting depends on intrinsic mechanisms and is independent from cardiac growth. Furthermore, genetic experiments indicate that looping requires proper tissue patterning. We conclude that cardiac looping involves twisting of the chambers around the atrioventricular canal, which requires correct tissue patterning by Tbx5a.Analysis and StochasticsAnimal science
Crystal chemistry search of multiferroics with the stereochemically active lone pair
On the basis of our previous studies of magnetoelectric ordering of BiFeO3,
TbMnO3, TbMn2O5 and BiMn2O5 we formulate the crystal chemistry criteria for the
search of multiferroics and reveal potential multiferroics Pb2Cu(OH)4Cl2,
Pb5Cr3F19, Mn(SeO3){\dot}H2O and BiPbSr2MnO6 each containing the ion with a
lone pair.Comment: 4 pages, 8 figures,submitted to J Supercond Nov Mag
Advances in ab-initio theory of Multiferroics. Materials and mechanisms: modelling and understanding
Within the broad class of multiferroics (compounds showing a coexistence of
magnetism and ferroelectricity), we focus on the subclass of "improper
electronic ferroelectrics", i.e. correlated materials where electronic degrees
of freedom (such as spin, charge or orbital) drive ferroelectricity. In
particular, in spin-induced ferroelectrics, there is not only a {\em
coexistence} of the two intriguing magnetic and dipolar orders; rather, there
is such an intimate link that one drives the other, suggesting a giant
magnetoelectric coupling. Via first-principles approaches based on density
functional theory, we review the microscopic mechanisms at the basis of
multiferroicity in several compounds, ranging from transition metal oxides to
organic multiferroics (MFs) to organic-inorganic hybrids (i.e. metal-organic
frameworks, MOFs)Comment: 22 pages, 9 figure
The cardiovascular risk profile of middle-aged women with polycystic ovary syndrome
Objectives: Contradictory results have been reported regarding the association between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD). We assessed the cardiometabolic phenotype and prevalence of CVD in middle-aged women with PCOS, compared with age-matched controls from the general population, and estimated 10-year CVD risk and cardiovascular health score. Design: A cross-sectional study. Participants: 200 women aged >45 with PCOS, and 200 age-matched controls. Measurements: Anthropometrics, insulin, lipid levels, prevalence of metabolic syndrome and type II diabetes. Ten-year Framingham risk score and the cardiovascular health score were calculated, and carotid intima-media thickness (cIMT) was measured. Results: Mean age was 50.5 years (SD = 5.5) in women with PCOS and 51.0 years (SD = 5.2) in controls. Increased waist circumference, body mass index and hypertension were more often observed in women with PCOS (P <.001). In women with PCOS, the prevalence of type II diabetes and metabolic syndrome was not significantly increased and lipid levels were not different from controls. cIMT was lower in women with PCOS (P <.001). Calculated cardiovascular health and 10-year CVD risk were similar in women with PCOS and controls. Conclusions: Middle-aged women with PCOS exhibit only a moderately unfavourable cardiometabolic profile compared to age-matched controls, even though they present with an increased BMI and waist circumference. Furthermore, we found no evidence for increased (10-year) CVD risk or more severe atherosclerosis compared with controls from the general population. Long-term follow-up of women with PCOS is necessary to provide a definitive answer concerning lon
Track E Implementation Science, Health Systems and Economics
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138412/1/jia218443.pd
More than smell - COVID-19 is associated with severe impairment of smell, taste, and chemesthesis
Recent anecdotal and scientific reports have provided evidence of a link between COVID-19 and chemosensory impairments, such as anosmia. However, these reports have downplayed or failed to distinguish potential effects on taste, ignored chemesthesis, and generally lacked quantitative measurements. Here, we report the development, implementation, and initial results of a multilingual, international questionnaire to assess self-reported quantity and quality of perception in 3 distinct chemosensory modalities (smell, taste, and chemesthesis) before and during COVID-19. In the first 11 days after questionnaire launch, 4039 participants (2913 women, 1118 men, and 8 others, aged 19-79) reported a COVID-19 diagnosis either via laboratory tests or clinical assessment. Importantly, smell, taste, and chemesthetic function were each significantly reduced compared to their status before the disease. Difference scores (maximum possible change ±100) revealed a mean reduction of smell (-79.7 ± 28.7, mean ± standard deviation), taste (-69.0 ± 32.6), and chemesthetic (-37.3 ± 36.2) function during COVID-19. Qualitative changes in olfactory ability (parosmia and phantosmia) were relatively rare and correlated with smell loss. Importantly, perceived nasal obstruction did not account for smell loss. Furthermore, chemosensory impairments were similar between participants in the laboratory test and clinical assessment groups. These results show that COVID-19-associated chemosensory impairment is not limited to smell but also affects taste and chemesthesis. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms. © 2020 The Author(s) 2020. Published by Oxford University Press. All rights reserved
Black box tussen aanbod, werving en selectie van vrouwen: Onderzoek naar genderpraktijken in de benoemingen voor leden van RvB's en RvC's in het Nederlandse bedrijfsleven
Contains fulltext :
162255.pdf (publisher's version ) (Open Access)Dit onderzoek gaat over de valkuilen in het wervings- en selectieproces, waardoor vrouwen minder kans maken benoemd te worden. Opvallend is dat de onderzoekers stellen dat bedrijven die moeite doen om een vrouw te vinden, daar ook in slagen. De geschikte vrouwen zijn er wel, maar zonder inspanning worden ze niet gevonden. Deze vrouwen kunnen gevonden worden door een expliciete wens te uiten een vrouw te benoemen, het juiste search bureau een duidelijke opdracht te geven en het loslaten van het klassieke profiel voor een benoeming dat vaak meer van hetzelfde vraagt. De rol van executive search bureaus is opvallend. De onderzoekers vonden in een enkel geval dat een van deze bureaus geen vrouw voordroeg, ook al was het de wens van het bedrijf om wel een vrouw te benoemen. De onderzoekers stellen mede daarom dat goede intenties alleen niet genoeg zijn, er moet ook naar gehandeld worden door controle te houden op het proces, hierop te reflecteren en zo nodig ook te interveniëren.42 p
Ethanol from sugar beet in The Netherlands: energy production and efficiency
Prospects for ethanol production from sugar beet in The Netherlands have been analysed using measured production data from two experimental farms and literature on beet to ethanol conversion. The analyses include beet cultivation and harvesting, transport to the factory, conversion into ethanol and delivery of the ethanol to distribution points. Under the prevailing conditions, ethanol production from sugar beet shows to be reasonably energy efficient. A net energy production has been calculated of 32 and 37 GJ/ha. Crop and ethanol yields are above those reported elsewhere, as is the energy use per hectare which is related to crop yield. Applying alternative energy generating technology at the ethanol factory suggests that considerable energy gains can be realised. Another source of variation is the allocation ratio of energy to ethanol and by-products. The calculations suggest that the prospects for ethanol production from sugar beet in Europe can be considerable, if energy inputs can be reduced, by using crop residue
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