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Item does not contain fulltext, BACKGROUND: Cyclooxygenase inhibitors are commonly used in infants with patent ductus arteriosus (PDA), but the benefit of these drugs is uncertain. METHODS: In this multicenter, noninferiority trial, we randomly assigned infants with echocardiographically confirmed PDA (diameter, >1.5 mm, with left-to-right shunting) who were extremely preterm (<28 weeks' gestational age) to receive either expectant management or early ibuprofen treatment. The composite primary outcome included necrotizing enterocolitis (Bell's stage IIa or higher), moderate to severe bronchopulmonary dysplasia, or death at 36 weeks' postmenstrual age. The noninferiority of expectant management as compared with early ibuprofen treatment was defined as an absolute risk difference with an upper boundary of the one-sided 95% confidence interval of less than 10 percentage points. RESULTS: A total of 273 infants underwent randomization. The median gestational age was 26 weeks, and the median birth weight was 845 g. A primary-outcome event occurred in 63 of 136 infants (46.3%) in the expectant-management group and in 87 of 137 (63.5%) in the early-ibuprofen group (absolute risk difference, -17.2 percentage points; upper boundary of the one-sided 95% confidence interval [CI], -7.4; P<0.001 for noninferiority). Necrotizing enterocolitis occurred in 24 of 136 infants (17.6%) in the expectant-management group and in 21 of 137 (15.3%) in the early-ibuprofen group (absolute risk difference, 2.3 percentage points; two-sided 95% CI, -6.5 to 11.1); bronchopulmonary dysplasia occurred in 39 of 117 infants (33.3%) and in 57 of 112 (50.9%), respectively (absolute risk difference, -17.6 percentage points; two-sided 95% CI, -30.2 to -5.0). Death occurred in 19 of 136 infants (14.0%) and in 25 of 137 (18.2%), respectively (absolute risk difference, -4.3 percentage points; two-sided 95% CI, -13.0 to 4.4). Rates of other adverse outcomes were similar in the two groups. CONCLUSIONS: Expectant management for PDA in extreme

We study the effect an atmosphere has on pebble orbits and spin build-up on a planet's surface during pebble accretion in the extreme case of a static atmosphere. We numerically integrate the equations of motion of pebbles in a planar, global frame with a planet, a central star and gas from a protoplanetary disc. An adiabatic atmosphere is then placed around the planet, and the spin deposited onto the planet's surface is measured. These simulations are evaluated for different distances to the star, Stokes numbers, and planet masses. Pebble feedback to the gas is not taken into account. We find that a static atmosphere dampens the spin the planet's surface receives by absorbing part of the angular momentum of the pebbles and circularising their orbits. This could prevent the excessive spin values predicted in some 3D pebble accretion simulations without an atmosphere. For planets larger than 0.5 Earth masses, a stationary atmosphere absorbs all angular momentum, leaving no spin for the surface. Significant quantities of angular momentum are stored in the inner and intermediate atmosphere ($<0.3$ Bondi radii). Depending on the atmospheric and disc model, this spin could be transported either to the disc through atmospheric recycling or to the planet through drag between the surface and the atmosphere. Further research is required to quantify the spin transfer within the atmosphere., Comment: 18 pages, 14 figures, Accepted for publication in Astronomy and Astrophysics (A&A)

Item does not contain fulltext, BACKGROUND: A Dutch committee for National Guidelines in Neonatology developed nineteen evidence- and consensus-based guidelines to be used in all Dutch neonatal intensive care units (NICUs). The primary goal was to make clinical practices more uniform and consistent. OBJECTIVE: This study investigated to what extent the guidelines were implemented and which factors played a role in implementation. STUDY DESIGN: A mixed method study design was used to investigate both the level and the process of implementation. A nationwide, multicenter, cross-sectional survey was performed using a validated instrument for measuring the level of implementation (Normalization MeAsure Development questionnaire, NoMAD). The number of implemented guidelines per NICU and the frequency and content of the amendments that NICUs made to the original consensus guidelines were analyzed. Through semi-structured interviews, perceived barriers and facilitators for implementation were explored. PARTICIPANTS: Fellows and neonatologists working at all ten Dutch level 3-4 NICUs were eligible. RESULTS: On an average, NICUs implemented 12.6 (of 19) guidelines (range 6-17). The Normalization Process Scale was 54 (of 65). Main influencing factors impeding implementation were guideline-related (e.g., unpractical, lengthy guidelines) and personal (e.g., an active representative responsible for local implementation). CONCLUSION: The implementation of our guidelines appears to be successful. Ways for improvement can be distinguished in personal, guideline-related and external factors. Empowerment of local representatives was considered most essential.

Binary solar system objects are common and range from satellite systems with very large mass ratios $M_1/M_2$ to mass ratios very close to unity. A well-known example of a binary is the Pluto-Charon system. With Charon only eight times less massive than Pluto the question arises as for many other systems, why the mass-ratio is still close to unity. There is much evidence that (binary) planet(esimal) formation happened early, when the protoplanetary gas disk was still around. It is likely that (some of) these binaries grew up together subject to pebble accretion. Here we focus on the question of how the mass arriving in the gravitational influence zone of the binary during pebble accretion, is distributed over the binary components. Does the accretion through time lead to a converging mass ratio, or to a diverging mass ratio? We numerically integrate pebble paths in the same well-known fashion as for a single mass subject to pebble accretion and track what the efficiency of accretion is for the two separate binary components, compared to a single body with the same mass. These numerical simulations are done for a range of binary mass-ratios, mutual separations, Stokes numbers and two orbital distances, 2.5 and 39 au. We find that in the limit where pebbles start to spiral around the primary (this holds for relatively large pebbles), the pebble preferentially collides with the secondary, causing the mass ratio to converge towards unity on Myr timescales. In this regime the total sweep-up efficiency can lower to half that of a pebble-accreting single body because pebbles that are thrown out of the system, after close encounters with the system. The results show that systems such as Pluto-Charon and other larger equal mass binaries could well have co-accreted by means of pebble accretion in the disk phase without producing binaries with highly diverging mass-ratios., Comment: 10 pages, 8 figures, submitted to Astronomy and Astrophysics

Intoxication can be a factor in unwanted sex, but research on the extent of the issue in both women and men is limited. We assessed the prevalence, correlates, and 10-year time-trends of unwanted sex due to intoxication among a representative sample of 4,279 women and 3,875 men aged 16–69 years in Australia and considered how these vary by gender. In 2012–13, 16% of women and 10% of men reported ever having had a sexual experience when they “did not want to because they were too drunk or high at the time.” For both women and men, this was associated with younger age, bisexual activity, and reports of lifetime injection drug use, sexually transmitted infections, and forced sex. Among women only, it was associated with drinking above guideline levels and ever having terminated a pregnancy. Among men only, it was associated with current tobacco smoking, elevated psychosocial distress, and poor general health. Compared with 2001–02 data, fewer men reported unwanted intoxicated sex, while there were no changes for women as a whole. Interpreting these findings through an intersectional assemblage framework supports stronger understanding of the multiple factors influencing sexuality and substance use with implications for promoting equity, safety, and sexual health.

This chapter describes perspectives on studying cultural differences in alcohol consumption and reviews the relevant literature. After introducing the concept of culture and the main approaches used to study drinking cultures, different conceptualisations of such cultures are discussed. The chapter includes a systematic review of the recent literature on drinking cultures. It ends with a discussion of strengths and weaknesses of existing literature on drinking cultures, gaps in the field and directions for future research.

Background: Early Intervention in Psychosis (EIP) services improve health outcomes for young people with psychosis in the medium–long term, but 25% of young people disengage in the first 12 months with costs to their mental health, families, society and the NHS. This study will evaluate the effectiveness, cost-effectiveness and implementation of a team-based motivational Early Youth Engagement (EYE-2) intervention. Method: The study design is a cluster randomised controlled trial (RCT) with economic evaluation, comparing the EYE-2 intervention + standardised EIP service to standardised EIP service alone, with randomisation at the team level. A process evaluation will evaluate the delivery of the intervention qualitatively and quantitatively across contexts. The setting is 20 EIP teams in 5 sites: Manchester, South London, East Anglia, Thames Valley and Hampshire. Participants are young people (14–35 years) with first episode psychosis, and EIP staff. The intervention is the team-based motivational engagement (EYE-2) intervention, delivered alongside standardised EIP services, and supported by additional training, website, booklets and social groups. The comparator is the standardised EIP service. Both interventions are delivered by EIP clinicians. The primary outcome is time to disengagement (time in days from date of allocation to care coordinator to date of last contact following refusal to engage with EIP service, or lack of response to EIP contact for a consecutive 3-month period). Secondary outcomes include mental and physical health, deaths, social and occupational function, recovery, satisfaction and service use at 6, 12, 18 and 24 months. A 12-month within-trial economic evaluation will investigate cost-effectiveness from a societal perspective and from an NHS perspective. Discussion: The trial will provide the first test of an engagement intervention in standardised care, with the potential for significant impact on the mental health and wellbeing of young

We discuss options to reform the EU genetically modified organism (GMO) regulatory framework, make risk assessment and decision-making more consistent with scientific principles, and lay the groundwork for international coherence. In this third of three articles, we focus on labeling and coexistence as well as discuss the political reality and potential ways forward., Not duplicate with DiVA 1413755.Not duplicate with DiVA 1597019.QC 20200714. QC 20210923.

The authors report a high prevalence of delirium in COVID-19 old patients admitted in an academic hospital. During the recent COVID-19 period, delirium was present in 38% of old patients admitted with delirium at the COVID ward of the Erasmus MC University Medical Center of Rotterdam. We do not know in which patients COVID-19 can cause delirium; however, considering the high prevalence of delirium in COVID-19 old patients and the potential serious consequences, attention is needed in order to reduce disability and mortality in this vulnerable category of patients.

Achtergrond: Scholieren die pestgedrag vertonen lopen een verhoogd risico op het ontwikkelen van depressieve gevoelens en het vertonen van antisociaal gedrag. Rots en watertraining (R&W) is gericht op het verminderen van pestgedrag onder scholieren door het verhogen van hun zelfcontrole. Doel: In deze studie werd de effectiviteit van R&W op het verminderen van pestgedrag onder vmbo-scholieren onderzocht. Daarnaast werd onderzocht of zelfcontrole een mediator is in het verband tussen R&W en pestgedrag. Methode: Eerste klas vmboscholieren (660 jongens en 631 meisjes) met een leeftijd van 11 tot 15 jaar (M = 12,81, SD = 0,66) werden verdeeld in vier condities: ‘licht’ (een kernteam van leraren is getraind in R&W), ‘standaard’ (het hele schoolteam is getraind in R&W), ‘plus’ (het hele schoolteam is getraind en ouders zijn betrokken) of de ‘controleconditie’ (gebruikelijk anti-pestbeleid). Scholieren vulden een vragenlijst in om pestgedrag, gemeten met de ‘Olweus Bully/Victim-vragenlijst’, en zelfcontrole, gemeten met de ‘Self-Control Scale’ en de ‘Monetary Choice-Vragenlijst’, te onderzoeken. Resultaten: ANCOVA toonde aan dat de conditiegroepen niet verschilden in pestgedrag op de nameting, waarbij gecontroleerd werd voor pestgedrag op de voormeting. Verder bleek uit mediatieanalyse, onderzocht met de mediatiemethode van Baron en Kenny (1986), dat zelfcontrole geen mediator is in het verband tussen R&W en pestgedrag. Discussie: Huidig onderzoek wijst uit dat R&W niet effectiever is in het verminderen van pestgedrag dan het gebruikelijke anti-pestbeleid en dat zelfcontrole niet fungeert als mediator in dit verband. De implementatie van R&W op vmbo-scholen voor het verminderen van pestgedrag wordt niet aanbevolen.

Hyperhydricity (HH) occurs when plants are faced with accumulation of water and reduction of air in the apoplast of the leaves. One of the characteristics of hyperhydric plants is the reduction of cell wall lignification (hypolignification), but how this is related to the abnormalities is still unclear. Lignin is hydrophobic and based on this it can be speculated that a reduction in lignin levels leads to more capillary action of the cell wall and, consequently, to more water in the intercellular spaces. p-coumaric acid is a hydroxy derivative of cinnamic acid and a precursor for lignin and flavonoids in higher plants. In the present work, the relative amount of apoplast water and air to the total apoplast volume of Arabidopsis thaliana wild-type (Col-0) leaves was evaluated. Exogenously applied p-coumaric acid can be channelled into the phenylpropanoid pathway through action of the enzyme 4-hydroxycinnamoyl-CoA ligase (4CL), ultimately resulting in an increase in the total lignin content. Exogenously applied p-coumaric acid led to increases in apoplastic air and lowering of apoplastic water in seedlings grown on medium solidified with gelrite. The symptoms of HH are also greatly diminished. These findings corroborate our hypothesis that lignin plays a role in the development of the HH and that an increase of lignin production by exogenously applying p-coumaric acid can lead to a decrease of water in the apoplast and thus to a reduction in the occurrence of HH.

Effects of prolonged darkness on Arctic phytoplankton composition were investigated with lab experimentsand a pigment time series in Kongsfjorden, Spitsbergen (78�550N). Chlorophylla(Chla), pigment composition,particulate organic carbon, cell numbers, and photosynthetic characteristics were studied in Arctic diatoms(Thalassiosira antarctica,Thalassiosira nordenskioeldii) andflagellates (Rhodomonassp.,Micromonassp.) during8 weeks of darkness and subsequent recovery in irradiance. Loss of photosynthetic functionality after 2 weeks ofdarkness was reversible in all species when returned to irradiance. Diatoms were more resistant to prolonged dark-ness (> 2 weeks) compared to theflagellates, with lower decline rates of Chlaand maximum quantum yield ofPSII.T. nordenskioeldiishowed rapid growth during recovery throughout 8 weeks of dark incubation, whereasrecovery offlagellates diminished within 4 weeks. Ratios of taxonomic marker pigments relative to Chlaof allspecies showed limited variation during 8 weeks of dark incubation. The experimentally observed enhanced darksurvival of diatoms was in agreement with pigment observations during four polar nights (2013–2017) inKongsfjorden, which showed increased relative diatom abundance during declining biomass (down to0.02 mg Chlam−3). Therefore, a period of prolonged darkness gives Arctic diatoms a head start during the earlystages of the spring bloom. The taxon-specific survival traits can influence the geographical distribution of dia-toms andflagellates within the polar oceans and their phenology. Furthermore, the persistence of Chlaof non-viable phytoplankton during darkness might influence biomass estimates during the polar night.

Most major planetary bodies in the solar system rotate in the same direction as their orbital motion: their spin is prograde. Theoretical studies to explain the direction as well as the magnitude of the spin vector have had mixed success. When the accreting building blocks are $\sim$ km-size planetesimals -- as predicted by the classical model -- the accretion process is so symmetric that it cancels out prograde with retrograde spin contributions, rendering the net spin minute. For this reason, the currently-favored model for the origin of planetary rotation is the giant impact model, in which a single collision suffices to deliver a spin, which magnitude is close to the breakup rotation rate. However, the giant impact model does not naturally explain the preference for prograde spin. Similarly, an increasing number of spin-vector measurement of asteroids also shows that the spin vector of large (primordial) asteroids is not isotropic. Here, we re-assess the viability of smaller particles to bestow planetary bodies with a net spin, focusing on the pebble accretion model in which gas drag and gravity join forces to accrete small particles at a large cross section. Similar to the classical calculation for planetesimals, we integrate the pebble equation of motion and measure the angular momentum transfer at impact. We consider a variety of disk conditions and pebble properties and conduct our calculations in the limits of 2D (planar) and 3D (homogeneous) pebble distributions. We find that in certain regions of the parameter space the angular momentum transfer is significant, much larger than with planetesimals and on par with or exceeding the current spin of planetary bodies., Comment: Accepted for publication in Icarus

‘’How could the bi-directional flow profile at the Brouwersdam be guided through the system in such a way that the water management is satisfied while ensuring critical factors like power generation and economic feasibility are suitably addressed?’’

Item does not contain fulltext, Difficulties with anger regulation in individuals with mild intellectual disability or borderline intellectual functioning (MID-BIF) are often associated with aggressive behaviour. Psychomotor therapy (PMT), a mind-body intervention often applied in Dutch facilities for this target group, uses body awareness and physical activities as a medium to learn how to gain control over one’s anger and reduce aggressive behaviour. With Intervention Mapping as a framework, 17 Dutch psychomotor therapists were asked to describe their PMT programme to investigate its content and coherence. Results suggested that interoceptive awareness (IA) and adaptive coping skills (ACS) are key elements of the PMT programmes. The theoretical basis of the PMT programmes is however limited and specific instruments for evaluating PMT are not available yet, especially for IA. Psychomotor therapists would gain from a well-described PMT programme. Future research is warranted on IA, and specific instruments need to be developed and validated for this target group.

Item does not contain fulltext

Background: In critically ill (preterm) neonates, central venous catheters (CVCs) are increasingly used for administration of medication or parenteral nutrition. A serious complication, however, is the development of catheter-related thrombosis (CVC-thrombosis), which may resolve by itself or cause severe complications. Due to lack of evidence, management of neonatal CVC-thrombosis varies among neonatal intensive care units (NICUs). In the Netherlands an expert-based national management guideline has been developed which is implemented in all 10 NICUs in 2014. Methods: The NEOCLOT study is a multicentre prospective observational cohort study, including 150 preterm and term infants (0-6 months) admitted to one of the 10 NICUs, developing CVC-thrombosis. Patient characteristics, thrombosis characteristics, risk factors, treatment strategies and outcome measures will be collected in a web-based database. Management of CVC-thrombosis will be performed as recommended in the protocol. Violations of the protocol will be noted. Primary outcome measures are a composite efficacy outcome consisting of death due to CVC-thrombosis and recurrent thrombosis, and a safety outcome consisting of the incidence of major bleedings during therapy. Secondary outcomes include individual components of primary efficacy outcome, clinically relevant non-major and minor bleedings and the frequency of risk factors, protocol variations, residual thrombosis and post thrombotic syndrome. Discussion: The NEOCLOT study will evaluate the efficacy and safety of the new, national, neonatal CVC-thrombosis guideline. Furthermore, risk factors as well as long-term consequences of CVC-thrombosis will be analysed.

The original version of this Article contained an error in the spelling of the author Pleuntje J. van der Sluijs, which was incorrectly given as Eline (P. J.) van der Sluijs. This has now been corrected in both the PDF and HTML versions of the Article.

_Background:_ Much controversy exists about the optimal management of a patent ductus arteriosus (PDA) in preterm infants, especially in those born at a gestational age (GA) less than 28weeks. No causal relationship has been proven between a (haemodynamically significant) PDA and neonatal complications related to pulmonary hyperperfusion and/or systemic hypoperfusion. Although studies show conflicting results, a common understanding is that medical or surgical treatment of a PDA does not seem to reduce the risk of major neonatal morbidities and mortality. As the PDA might have closed spontaneously, treated children are potentially exposed to iatrogenic adverse effects. A conservative approach is gaining interest worldwide, although convincing evidence to support its use is lacking. _Methods:_ This multicentre, randomised, non-inferiority trial is conducted in neonatal intensive care units. The study population consists of preterm infants (GA<28weeks) with an echocardiographic-confirmed PDA with a transductal diameter>1.5mm. Early treatment (between 24 and 72h postnatal age) with the cyclooxygenase inhibitor(COXi) ibuprofen (IBU) is compared with an expectative management (no intervention intended to close a PDA). The primary outcome is the composite of mortality, and/or necrotising enterocolitis (NEC) Bell stage ≥ IIa, and/or bronchopulmonary dysplasia (BPD) defined as the need for supplemental oxygen, all at a postmenstrual age (PMA) of 36weeks. Secondary outcome parameters are short term sequelae of cardiovascular failure, comorbidity and adverse events assessed during hospitalization and long-term neurodevelopmental outcome assessed at a corrected age of 2 years. Consequences regarding health economics are evaluated by cost effectiveness analysis and budget impact analysis. _Discussion:_ As a conservative approach is gaining interest, we investigate whether in preterm infants, born at a GA less than 28weeks, with a PDA an expectative management is non-inferior to

Contains fulltext : 169851.pdf (publisher's version ) (Open Access), AIM: This study assessed whether increased amino acid and energy intake in preterm infants during the first week of life was associated with improved neurodevelopment at the corrected age (CA) of 24 months. METHODS: We evaluated preterm infants from two consecutive cohorts in 2004 (Cohort 1) and 2005 (Cohort 2) with different nutritional intakes in the Netherlands. Nutritional intake and growth were recorded until week 5 and after discharge. Neurodevelopment was determined using the Bayley Scales of Infant Development - Second Edition at a CA of 24 months. RESULTS: Compared to Cohort 1 (n = 56), Cohort 2 (n = 56) received higher nutritional intake during week 1 (p < 0.001). The weight gain in Cohort 2 was higher until week 5, especially among boys (p < 0.002). The mean Mental Developmental Index (MDI) scores did not differ, but Cohort 2 was associated with an increased chance of having an MDI >/= 85, with an odds ratio of 6.4 and 95% confidence interval (CI) of 1.5-27.4, among all girls with a higher protein intake (5.3, 1.2-23.3). The Psychomotor Developmental Index increased with increasing nutritional intake, especially among boys (beta-coefficient 3.1, 95% CI 0.2-6.0). CONCLUSION: Higher nutritional intake was associated with different improvements in growth and neurodevelopment in boys and girls.

In a national telephone-based survey, information on sexual behaviour and outcomes were collected from 20 091 randomly selected Australians in 2012–13. Data were weighted and analysed to determine the proportion of those who had received school-based sex education and to examine the associations between sex education and sexual health outcomes, specifically a history of a sexually transmissible infection (STI), early pregnancy, contraception use at first sex, and level of STI knowledge. Just over half the respondents (53%; n = 19 836) reported receiving sex education that included information about condoms and contraception. Using logistic regression analysis after adjusting for age, education and non-English-speaking background, we found that sex education was strongly associated with increased odds of using contraception at first vaginal intercourse (odds ratio (OR) = 1.57; 95% confidence interval (CI) 1.44–1.71; P < 0.001) and higher levels of STI knowledge (OR = 1.75; 95% CI 1.46–2.12; P < 0.001).

Bright ring-like structure emission of the CN molecule has been observed in protoplanetary disks. We investigate whether such structures are due to the morphology of the disk itself or if they are instead an intrinsic feature of CN emission. With the intention of using CN as a diagnostic, we also address to which physical and chemical parameters CN is most sensitive. A set of disk models were run for different stellar spectra, masses, and physical structures via the 2D thermochemical code DALI. An updated chemical network that accounts for the most relevant CN reactions was adopted. Ring-shaped emission is found to be a common feature of all adopted models; the highest abundance is found in the upper outer regions of the disk, and the column density peaks at 30-100 AU for T Tauri stars with standard accretion rates. Higher mass disks generally show brighter CN. Higher UV fields, such as those appropriate for T Tauri stars with high accretion rates or for Herbig Ae stars or for higher disk flaring, generally result in brighter and larger rings. These trends are due to the main formation paths of CN, which all start with vibrationally excited H2* molecules, that are produced through far ultraviolet (FUV) pumping of H2. The model results compare well with observed disk-integrated CN fluxes and the observed location of the CN ring for the TW Hya disk. CN rings are produced naturally in protoplanetary disks and do not require a specific underlying disk structure such as a dust cavity or gap. The strong link between FUV flux and CN emission can provide critical information regarding the vertical structure of the disk and the distribution of dust grains which affects the UV penetration, and could help to break some degeneracies in the SED fitting. In contrast with C2H or c-C3H2, the CN flux is not very sensitive to carbon and oxygen depletion., Comment: New version of paper, correcting too high H2 excitation rates and consequently too high CN column densities. Qualitative conclusions of the paper remain unchanged. Quantitatively, the CN column densities are an order of magnitude lower whereas fluxes decrease by a factor of 3-4. Rings are larger by up to a factor of 2. 13 pages, 19 figures, accepted for publication in A&A

(Abridged) Through spectrally unresolved observations of high-J CO transitions, Herschel-PACS has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components using spectrally resolved Herschel-HIFI data. Observations are presented of the highly excited CO line J=16-15 with Herschel-HIFI toward 24 low-mass protostellar objects. The spectrally resolved profiles show two distinct velocity components: a broad component with an average FWHM of 20 km/s, and a narrower component with a FWHM of 5 km/s that is often offset from the source velocity. The average rotational temperature over the entire profile, as measured from comparison between CO J=16-15 and 10-9 emission, is ~300 K. A radiative-transfer analysis shows that the average H2O/CO column-density ratio is ~0.02, suggesting a total H2O abundance of ~2x10^-6. Two distinct velocity profiles observed in the HIFI line profiles suggest that the CO ladder observed with PACS consists of two excitation components. The warm component (300 K) is associated with the broad HIFI component, and the hot component (700 K) is associated with the offset HIFI component. The former originates in either outflow cavity shocks or the disk wind, and the latter in irradiated shocks. The ubiquity of the warm and hot CO components suggests that fundamental mechanisms govern the excitation of these components; we hypothesize that the warm component arises when H2 stops being the dominant coolant. In this scenario, the hot component arises in cooling molecular H2-poor gas just prior to the onset of H2 formation. High spectral resolution observations of highly excited CO transitions uniquely shed light on the origin of warm and hot gas in low-mass protostellar objects., Comment: Accepted for publication in A&A

In molecular outflows from forming low-mass protostars, most oxygen is expected to be locked up in water. However, Herschel observations have shown that typically an order of magnitude or more of the oxygen is still unaccounted for. To test if the oxygen is instead in atomic form, SOFIA-GREAT observed the R1 position of the bright molecular outflow from NGC1333-IRAS4A. The [OI] 63 um line is detected and spectrally resolved. From an intensity peak at +15 km/s, the intensity decreases until +50 km/s. The profile is similar to that of high-velocity (HV) H2O and CO 16-15, the latter observed simultaneously with [OI]. A radiative transfer analysis suggests that ~15% of the oxygen is in atomic form toward this shock position. The CO abundance is inferred to be ~10^-4 by a similar analysis, suggesting that this is the dominant oxygen carrier in the HV component. These results demonstrate that a large portion of the observed [OI] emission is part of the outflow. Further observations are required to verify whether this is a general trend., Comment: Accepted for publication in A&A Letters

[Abridged] We present spectroscopic observations in H$_{2}$O, CO and related species with \textit{Herschel} HIFI and PACS, as well as ground-based follow-up with the JCMT and APEX in CO, HCO$^{+}$ and isotopologues, of a sample of 49 nearby ($d<$500\,pc) candidate protostars. These data are used to study the outflow and envelope properties of these sources. We also compile their continuum SEDs in order to constrain their physical properties. Water emission is dominated by shocks associated with the outflow, rather than the cooler, slower entrained outflowing gas probed by ground-based CO observations. These shocks become less energetic as sources evolve from Class 0 to Class I. The fraction of mass in the outflow relative to the total envelope (i.e. $M_{\mathrm{out}}/M_{\mathrm{env}}$) remains broadly constant between Class 0 and I. The median value ($\sim$1$\%$) is consistent with a core to star formation efficiency on the order of 50$\%$ and an outflow duty cycle on the order of 5$\%$. Entrainment efficiency, as probed by $F_{\mathrm{CO}}/\dot{M}_{\mathrm{acc}}$, is also invariant with source properties and evolutionary stage. The median value (6.3\kms{}) suggests an entrainment efficiency of between 30 and 60$\%$ if the wind is launched at $\sim$1AU. $L$[O\,{\sc i}] is strongly correlated with $L_{\mathrm{bol}}$ but not with $M_{\mathrm{env}}$, while low-$J$ CO is more closely correlated with the latter than the former. This suggests that [O\,{\sc i}] traces the present-day accretion activity while CO traces time-averaged accretion over the dynamical timescale of the outflow. $L$[O\,{\sc i}] does not vary from Class 0 to Class I, unlike CO and H$_{2}$O. This is likely due to the ratio of atomic to molecular gas in the wind increasing as the source evolves, balancing out the decrease in mass accretion rate. Infall signatures are detected in HCO$^{+}$ and H$_{2}$O in a few sources., Comment: Accepted to A&A, version after language editor corrections. 47 pages, 18 figures, 15 tables. The figures have been converted to pdf due to file-size considerations, which may lead to some degradation

In molecular outflows from forming low-mass protostars, most oxygen is expected to be locked up in water. However, Herschel observations have shown that typically an order of magnitude or more of the oxygen is still unaccounted for. To test if the oxygen is instead in atomic form, SOFIA-GREAT observed the R1 position of the bright molecular outflow from NGC 1333-IRAS4A. The [O I] 63 mu m line is detected and spectrally resolved. From an intensity peak at + 15 kms(-1), the intensity decreases until + 50 kms-1. The profile is similar to that of high-velocity (HV) H2O and CO 16-15, the latter observed simultaneously with [O I]. A radiative transfer analysis suggests that similar to 15% of the oxygen is in atomic form toward this shock position. The CO abundance is inferred to be similar to 10(-4) by a similar analysis, suggesting that this is the dominant oxygen carrier in the HV component. These results demonstrate that a large portion of the observed [O I] emission is part of the outflow. Further observations are required to verify whether this is a general trend.

Although shoreface nourishments are an increasingly interesting option for coastal managers to counteract coastal erosion, their design is often highly empirical. A better understanding of the way shoreface nourishments interact with the initial beach profile may help to reduce the degree of empiricism in nourishment design. Literature study has shown that numerical modelling is commonly used to design shoreface nourishments and to assess their development and efficiency. It has also shown that there are two dominant mechanism are to be expected from a shoreface nourishment to lower the coastal erosion. These mechanisms correspond to an increase in beach width and a lowering in significant wave height. Previous performed studies on shoreface nourishment design effects along the North-Holland coast (de Sonneville, 2012) concluded that the differentiating factors possibly influencing the counteraction of coastal erosion are; offshore distance, height and alongshore length. Therefore the objective of this study is to investigate how the significant wave height and beach width are affected by changing the; offshore distance, height and length of a shoreface nourishment using a process based modelling suite. These effects are divided in two different time scales: • First the long term shoreface nourishment effects are modelled in Delft3D to check how the beach width and wave height are affected after one year of morphological modelling. • The short term storm events effects of a shoreface nourishment are checked by modelling a storm event in XBeach. To see whether the effects per nourishment are alike for various beaches, two different cases are considered for the long term modelling approach. For the location of the two cases eyes fell on previous studies on shoreface nourishments in Noordwijk (NL) and Nags Head (NC,USA). Long term modelling results of both cases show that shoreface nourishments with low height and large alongshore length are best for lowering the signi, Civil Engineering and Geosciences, Hydraulic Engineering

Context. Through spectrally unresolved observations of high-J CO transitions, Herschel Photodetector Array Camera and Spectrometer (PACS) has revealed large reservoirs of warm (300 K) and hot (700 K) molecular gas around low-mass protostars. The excitation and physical origin of this gas is still not understood. Aims. We aim to shed light on the excitation and origin of the CO ladder observed toward protostars, and on the water abundance in different physical components within protostellar systems using spectrally resolved Herschel-HIFI data. Methods. Observations are presented of the highly excited CO line J = 16-15 (Eup/kB = 750 K) with the Herschel Heterodyne Instrument for the Far Infrared (HIFI) toward a sample of 24 low-mass protostellar objects. The sources were selected from the Herschel "Water in Star-forming regions with Herschel" (WISH) and "Dust, Ice, and Gas in Time" (DIGIT) key programs. Results. The spectrally resolved line profiles typically show two distinct velocity components: a broad Gaussian component with an average FWHM of 20 km s-1 containing the bulk of the flux, and a narrower Gaussian component with a FWHM of 5 km s-1 that is often offset from the source velocity. Some sources show other velocity components such as extremely-high-velocity features or "bullets". All these velocity components were first detected in H2O line profiles. The average rotational temperature over the entire profile, as measured from comparison between CO J = 16-15 and 10-9 emission, is ~300 K. A radiative-transfer analysis shows that the average H2O/CO column-density ratio is ~0.02, suggesting a total H2O abundance of ~2 × 10-6, independent of velocity. Conclusions. Two distinct velocity profiles observed in the HIFI line profiles suggest that the high-J CO ladder observed with PACS consists of two excitation components. The warm PACS component (300 K) is associated with the

Presentatie van het Groot TKI-BBE overleg op 8 maart 2017 in Geertruidenberg.

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We investigate the delivery of regular and deuterated forms of water from prestellar cores to circumstellar disks. We adopt a semi-analytical axisymmetric two-dimensional collapsing core model with post-processing gas-ice astrochemical simulations, in which a layered ice structure is considered. The physical and chemical evolutions are followed until the end of the main accretion phase. When mass averaged over the whole disk, a forming disk has a similar H2O abundance and HDO/H2O abundance ratio as their precollapse values (within a factor of 2), regardless of time in our models. Consistent with previous studies, our models suggest that interstellar water ice is delivered to forming disks without significant alteration. On the other hand, the local vertically averaged H2O ice abundance and HDO/H2O ice ratio can differ more, by up to a factor of several, depending on time and distance from a central star. Key parameters for the local variations are the fluence of stellar UV photons en route into the disk and the ice layered structure, the latter of which is mostly established in the prestellar stages. We also find that even if interstellar water ice is destroyed by stellar UV and (partly) reformed prior to disk entry, the HDO/H2O ratio in reformed water ice is similar to the original value. This finding indicates that some caution is needed in discussions on the prestellar inheritance of H2O based on comparisons between the observationally derived HDO/H2O ratio in clouds/cores and that in disks/comets. Alternatively, we propose that the ratio of D2O/HDO to HDO/H2O better probes the prestellar inheritance of H2O. It is also found that icy organics are more enriched in deuterium than water ice in forming disks. The differential deuterium fractionation in water and organics is inherited from the prestellar stages., Comment: 20 pages, 15 figures, accepted by A&A

How protostars accrete mass is one of the fundamental problems of star formation. High column densities and complex kinematical structures make direct observations challenging and they only provide a snapshot. Chemical tracers provide an interesting alternative to characterise the infall histories of protostars. Previous observations of H13CO+ towards the low-mass protostar IRAS15398-3359 showed a depression in the abundance. This is a sign of destruction of HCO+ by an enhanced presence of gaseous water in an extended region, possibly related to a recent burst in the accretion. Direct observations of water vapour can determine the exact extent of the emission and confirm the hypothesis that HCO+ is indeed a good tracer of the water snow-line. IRAS15398 was observed using ALMA at 0.5" resolution. Maps of HDO(101-000) and H218O(414-321) were taken simultaneously with observations of the CS(8-7) and N2H+(5-4) lines and continuum at 0.65 and 0.75 mm. The maps were interpreted using dust radiative transfer calculations of the protostellar infalling envelope with an outflow cavity. HDO is clearly detected and extended over the scales of the H13CO+ depression, although it is displaced by ~500 AU in the direction of the outflow. H218O is tentatively detected towards the red-shifted outflow lobe, but otherwise it is absent from the mapped region, which suggests that temperatures are low. Based on the temperature structure obtained from dust radiative transfer models, we conclude that the water was most likely released from the grains in an extended hour-glass configuration during a recent accretion burst. HDO is only detected in the region closest to the protostar, at distances of up to 500 AU. These signatures can only be explained if the luminosity has recently been increased by orders of magnitudes. Additionally, the densities in the outflow cones must be sufficiently low., Comment: Accepted for publication in A&A. 8 pages, 6 figures

Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides, such as CH+ and OH+, and also HCO+ that affect the chemistry of molecules such as water, provide complementary information on irradiation by far UV (FUV) or X-rays and gas temperature. The targeted lines of CH+, OH+, H2O+, C+ and CH are detected mostly in blue-shifted absorption. H3O+ and SH+ are detected in emission and only toward some high-mass objects. The observed line parameters and correlations suggest two different origins, related to gas entrained by the outflows and to the circumstellar envelope. The column density ratios of CH+/OH+ are estimated from chemical slab models, assuming that the H2 density is given by the specific density model of each object at the beam radius. For the low-mass YSOs the observed ratio can be reproduced for an FUV flux of 2-400 times the ISRF at the location of the molecules. In two high-mass objects, the UV flux is 20-200 times the ISRF derived from absorption lines, and 300-600 ISRF using emission lines. If the FUV flux required for low-mass objects originates at the central protostar, a substantial FUV luminosity, up to 1.5 L_sun, is required. There is no molecular evidence for X-ray induced chemistry in the low-mass objects on the observed scales of a few 1000 AU. For high-mass regions, the FUV flux required to produce the observed molecular ratios is smaller than the unattenuated flux expected from the central object(s) at the Herschel beam radius. This is consistent with an FUV flux reduced by circumstellar extinction or by bloating of the protostar., Comment: 40 pages, 97 figures, accepted by Astronomy and Astrophysics

The CV3 Pueblito de Allende meteorite is used to test new in situ methods to identify organic compounds. These methods can potentially be a good alternative to avoid the difficult extraction methods, reducing the risk of losing organic molecules and contaminating the samples with terrestrial organics. The distribution, formation, and characteristics of the organic compounds of the Pueblito de Allende meteorite are studied by Electron MicroProbe (EMP), Raman spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) and nuclear magnetic resonance (NMR). Elemental maps, spot analysis and Raman measurements show the heterogeneous distribution of organic compounds in the matrix and chondrules. The G- and D-bands are used to reveal the differences between the thermally stressed organics of Allende and the relative unaltered organics of other CV3 chondrites. The SERS method, where synthesized silver nanoparticles are added to the surface of minerals have an enhancement effect (~106) on organics, is used to show that this method works when the organics are added to the minerals in thin film. This study shows that the enhancements effects on the intensities of the organics are dramatically reduced when the silver colloids are used to determine the organic compounds imbedded in the matrix. The G- and D-band are enhanced slightly (101-102), but no other organic compounds could be detected. The addition of chloride ions used to stabilize the silver particles decreases the enhancements effects even more.

Due to the predicted rise in sea level, it is quite possible that river deltas in low-lying areas will start to drown. When the rate of sea level rise exceeds sediment accretion in a wetland, loss of delta land is inevitable. The Netherlands has many wetlands and the Biesbosch in the south-western part of the Netherlands is one of the best known examples. The area investigated in this thesis is called the Kleine Noordwaard. In this area, a recently inundated tidal freshwater wetland provides an ideal opportunity for investigating the sediment budget of such a wetland. This can give information on the survival chances of such a wetland. The main focus in this thesis is to gain information on the short term sediment budget in the Kleine Noordwaard. In order to answer this question, stream velocities and suspended sediment concentrations were measured. Using the suspended sediment measurements, maps of suspended sediment concentration were made. From the stream velocities, discharges were calculated which in turn were used for flux calculations. These flux values were used for sediment budget calculation in order to answer the main research question. Fall velocities were computed as well and used for the calculation of the trapping efficiency of the Kleine Noordwaard. Temporal differences in suspended sediment concentrations were seen on the maps which were made, the flux calculations and meteorological data. It has been found that the research area was a source of sediment during low river discharges and strong SSW winds. The area acted as a sink of sediment during high river discharges and low SSW winds and during average river discharges and strong NE winds. The mean median settling velocity of the suspended sediment was 0.04 mm/sec. The trapping values that were calculated using two different formulas varied between 51% and 71%. In contrast to the positive trapping efficiency of the Kleine Noordwaard, the calculated accretion rate of the area shows a smaller value

Project MARCH is designing and building an exoskeleton for paraplegic people in order for them to walk again and participate with it in the 2016 Cybathlon in Zürich. The exoskeleton has many sensors, which acquire data from their surroundings. Project MARCH required a system, which allows for wireless external monitoring of the exoskeleton., Electrical Engineering, Mathematics and Computer Science, Software Technology, TI3800

[Context] Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides such as CH+ and OH+ (and also HCO+), which affect the chemistry of molecules such as water, provide complementary information on irradiation by far-UV (FUV) or X-rays and gas temperature., [Aims] We explore hydrides of the most abundant heavier elements in an observational survey covering young stellar objects (YSOs) with different mass and evolutionary state. The focus is on hydrides associated with the dense protostellar envelope and outflows, contrary to previous work that focused on hydrides in diffuse foreground clouds., [Methods] Twelve YSOs were observed with HIFI on Herschel in six spectral settings providing fully velocity-resolved line profiles as part of the Water in star-forming regions with Herschel (WISH) program. The YSOs include objects of low (Class 0 and I), intermediate, and high mass, with luminosities ranging from 4 L⊙ to 2 × 105 L⊙., [Results] The targeted lines of CH+, OH+, H2O+, C+, and CH are detected mostly in blue-shifted absorption. H3O+ and SH+ are detected in emission and only toward some high-mass objects. The observed line parameters and correlations suggest two different origins related to gas entrained by the outflows and to the circumstellar envelope. The derived column densities correlate with bolometric luminosity and envelope mass for all molecules, best for CH, CH+, and HCO+. The column density ratios of CH+/OH+ are estimated from chemical slab models, assuming that the H2 density is given by the specific density model of each object at the beam radius. For the low-mass YSOs the observed ratio can be reproduced for an FUV flux of 2–400 times the interstellar radiation field (ISRF) at the location of the molecules. In two high-mass objects, the UV flux is 20–200 times the ISRF derived from absorption lines, and 300–600 ISRF using emission lines. Upper limits for the X-ray luminosity can be derived from H3O+ observations for some low-mass objects., [Conclusions] If the FUV flux required for low-mass objects originates at the central protostar, a substantial FUV luminosity, up to 1.5 L⊙, is required. There is no molecular evidence for X-ray induced chemistry in the low-mass objects on the observed scales of a few 1000 AU. For high-mass regions, the FUV flux required to produce the observed molecular ratios is smaller than the unattenuated flux expected from the central object(s) at the Herschel beam radius. This is consistent with an FUV flux reduced by circumstellar extinction or by bloating of the protostar.