Universality of rain event size distributions

We compare rain event size distributions derived from measurements in climatically different regions, which we find to be well approximated by power laws of similar exponents over broad ranges. Differences can be seen in the large-scale cutoffs of the distributions. Event duration distributions suggest that the scale-free aspects are related to the absence of characteristic scales in the meteorological mesoscale.Comment: 16 pages, 10 figure

Modeling the evolution space of breakage fusion bridge cycles with a stochastic folding process

Breakage-Fusion-Bridge cycles in cancer arise when a broken segment of DNA is duplicated and an end from each copy joined together. This structure then 'unfolds' into a new piece of palindromic DNA. This is one mechanism responsible for the localised amplicons observed in cancer genome data. The process has parallels with paper folding sequences that arise when a piece of paper is folded several times and then unfolded. Here we adapt such methods to study the breakage-fusion-bridge structures in detail. We firstly consider discrete representations of this space with 2-d trees to demonstrate that there are 2^(n(n-1)/2) qualitatively distinct evolutions involving n breakage-fusion-bridge cycles. Secondly we consider the stochastic nature of the fold positions, to determine evolution likelihoods, and also describe how amplicons become localised. Finally we highlight these methods by inferring the evolution of breakage-fusion-bridge cycles with data from primary tissue cancer samples

Obesity is underestimated using body mass index and waist-hip ratio in long-term adult survivors of childhood cancer

Objective: Obesity, represented by high body mass index (BMI), is a major complication after treatment for childhood cancer. However, it has been shown that high total fat percentage and low lean body mass are more reliable predictors of cardio

Shallow cumulus convection = Ondiepe cumulus convectie

Clouds play an important role in the earth's climate. Firstly, they are important in the radiative energy budget of the global atmosphere. Clouds absorb and reflect ultraviolet solar radiation, and emit infrared radiation depending on their temperature. Secondly, an important part of the vertical transport of heat, moisture and momentum in the atmosphere is associated with the relatively strong vertical motions inside certain types of clouds, also called convective clouds. These clouds often produce intense precipitation, and play an important role in the global water cycle. In the tropics near the equator, these clouds act as the engine for whole large-scale atmospheric circulations.This thesis is concerned with clouds in the lowest few kilometers of the atmosphere surrounding the earth. This sphere is also known as the atmospheric or planetary boundary layer (PBL), defined as the part of the atmosphere directly influenced by the proximity of the surface of the earth. In this layer the exchange takes place of heat and moisture between the earth and the atmosphere. Basically the boundary layer is formed and maintained by vertical motions of air, known as turbulence . The turbulence is driven by heating of air close to the surface, and by the drag on the horizontal winds by the roughness of the earth's surface. The resulting turbulent eddies mix heat, moisture and momentum throughout the boundary layer. As rising air cools adiabatically, some eddies can get cooled so much in certain situations that water droplets form inside them, forming cumuliform clouds. This type of clouds is the main subject of this thesis. More specifically, the research is focused on shallow cumulus clouds, also known as fair-weather cumulus.Because of their important role in the earth's radiative budget and in the vertical transport of air, it is essential for weather and climate prediction modelling to know where, when and to what extent cumuliform clouds occur. Since a few decades ago numerical models for the general circulation are used to make weather and climate predictions. Despite the rapid developments in supercomputing, the typical spatial and temporal resolutions used in state of the art models are still as large as 30 to 50km. These grid-spacings are still much too large to realistically resolve shallow cumulus clouds, as their dimensions are in the order of a few kilometers at maximum. Nevertheless, their strength lies in their numbers, as these clouds typically occur in whole populations covering large areas of the globe. In order to represent the impact of these clouds on the general atmospheric circulation which is to be resolved by the models, it is necessary to implement simplified formulas which mimic the presence of shallow cumulus clouds. This technique is known as parameterization. These formulations typically are dependent on a few relevant meteorological parameters. Due to the complexity of this problem much effort has already been put in the scientific research on cumulus convection.In parameterizations for cumulus it is custom to separate the modeling of turbulent transport in the cloud layer and in the dry air below the clouds. This often leads to unwanted interactions of the modeling of these mechanisms in the lower atmosphere. The purpose of the research project behind this thesis was twofold: firstly to comprehend and model the exchange of air between the subcloud layer and the cumulus clouds, and secondly to quantify and model the mixing of this ventilated air over the cloud layer. Associated with this approach is a study of the typical turbulent and geometrical variability of cumulus cloud populations. The research is performed using observations of natural cumulus clouds by aircraft, surface-based meteorological instrumentation, remote sensing devices on satellites and cloud radar. To supplement these datasets which are often scarce and incomplete on important points, use is also made of high-resolution numerical models for atmospheric flow, also known as large-eddy simulation . These models simulate a domain of ten by ten by five kilometers, including whole populations of cumulus clouds. These simulated fields are used as a virtual laboratory to study cumulus convection.Large-eddy simulation results on shallow cumulus convection are directly evaluated against detailed cloud observations in Chapter 3, using aircraft-measurements of the Small Cumulus Microphysics Study (SCMS) as well as high-resolution Landsat images. The results show that given the correct initial and boundary conditions the LES concept is capable of realistically predicting the bulk thermodynamic properties of temperature, moisture and liquid water content of the cumulus cloud ensemble as observed in SCMS. Furthermore the vertical component of the in-cloud turbulent kinetic energy and the cloud size distribution in LES were in agreement with the observations. Several hypotheses which make use of conditionally sampled fields were tested on the SCMS data. The magnitudes and the decrease with height of the bulk entrainmen t rate following from the SCMS data confirm the typical values first suggested by Siebesma and Cuijpers (1995) using LES results on the Barbados Oceanic and Meteorological Experiment (BOMEX). An alternative formulation of the lateral entrainment rate as a function of the liquid water content and the mean lapse rate agrees well with the original form based on the conserved variables. Applying the simplified equation for the cloud vertica l velocity by Simpson and Wiggert (1969) to the aircraft-measurements results in a reasonably closed budget. These results support the credibility of cloud statistics as produced by LES in general, and encourage its use as a tool for testing hypotheses and developing parameterizations of shallow cumulus cloud processes.The geometrical variability of shallow cumulus cloud populations is assessed in Chapter 4 by means of calculating cloud size densities. We find a power-law scaling at the small cloud sizes and the presence of a scale break. The corresponding functional parameters have values which are typical for observed populations. The scale-break size appears to be the relevant length-scale to non-dimensionalize the cloud size, as this causes a data-collapse of the cloud size densities over several different cumulus cases. These findings suggest that a universal functional form exists for the cloud size density of shallow cumulus. A better understanding of the scale-break size is essential for for a complete definition this function. The scale-break co-determines the cloud size density, and defines the intermediate dominating size in the mass flux and cloud fraction decompositions. Its intermediate position between the largest clouds and the grid-spacing in LES implies that the clouds which do matter are resolved well by LES.In Chapter 5 the (thermo)dynamic variability of shallow cumulus is visualized by means of conserved variable diagrams, showing the joint pdfs of the conserved thermodynamic variables and (vertical) momentum. This approach inspired the formulation of a multi parcel model, meant to at least partially reproduce the joint pdfs. A new conceptual model for the lateral mixing of such an updraft-parcel is presented, based on an adjustment time-scale for the dilution of the excess of the conserved properties of this updraft parcel over its environment. A statistical analysis of many LES clouds showed that this adjustment time-scale is constant in all clouds, which implies a lateral mixing rate which is inversely proportional to the vertical velocity. This dynamical feedback between thermodynamics and vertical momentum is shown to be capable of reproducing the cloud population-average characteristics as well as the increase of the in-cloud variances with height.Chapter 6 deals with the cloud-subcloud coupling, which manifests itself in many aspects of shallow cumulus topped boundary layers, not in the last place in the turbulent variability. The parameterization of the transport properties of the simplified top-hat pdf is expressed in the mass flux model, of which the closure at cloud base represents this cloud-subcloud interaction. Three closure methods for shallow cumulus are critically examined for the difficult case of a diurnal cycle of shallow cumulus over land. First the various closures are diagnostically evaluated in a large-eddy simulation of a diurnal cycle. Subsequently they are implemented in an offline 1D model to study their impact on the development of the modelled cloudy boundary layer. Significant moistening occurs in the subcloud mixed layer in the first hours after cloud onset in LES, which makes the boundary-layer equilibrium closure Tiedtke (1989) substantially overestimate the mass flux at cloud base. As a result the boundary layer deepens unrealistically rapid at that stage in the single column model. The adjustment closure on the convective available potential energy (CAPE) of Fritsch and Chappell (1980) fails at the early and final stages of the diurnal cycle, when the cloud base transport is controlled by subcloud layer properties. The subcloud convective velocity scale closure of Grant (2001) is promising, as it reproduces the timing of both the maximum and the final decrease of the cloud base mass flux in LES. Apparently this closure catches the coupling between the two layers at cloud base. As a consequence the development of the thermodynamic structure of the boundary layer in the 1D model strongly resembles that in LES.The validation of global weather and climate models with observations in general shows that in many situations the characteristics of clouds are not represented well. Especially concerning low convective clouds it has become clear that existing parameterizations for important meteorological parameters such as cloud cover and occurrence of different type of clouds do not always give realistic results. Misrepresentations of these parameters can lead to serious deviations in the modelled circulation and climatology. It is clear that further research and development is required in this field of meteorology. The results as presented in this thesis have contributed to this in several ways. The thermodynamic variability and population statistics of cumulus cloud fields has been further charted and quantified. The interaction between shallow cumulus cloud layers and subcloud layers has been analyzed and the performance of several well-known conceptual models for this interaction has been compared. The dynamics of mixing between cumulus clouds and their environment has been studied and captured in a coneptual model. Finally, it has been shown that the cloud populations as produced by LES models have realistic cloud size statistics and thermodynamic properties

Lanreotide Autogel 120 mg at extended dosing intervals in patients with acromegaly biochemically controlled with octreotide LAR: The LEAD study

Objective: To evaluate extended dosing intervals (EDIs) with lanreotide Autogel 120 mg in patients with acromegaly previously biochemically controlled with octreotide LAR 10 or 20 mg. Design and methods: Patients with acromegaly had received octreotide LAR 10 or 20 mg/4 weeks for R6 months and had normal IGF1 levels. Lanreotide Autogel 120 mg was administered every 6 weeks for 24 weeks (phase 1); depending on week-24 IGF1 levels, treatment was then administered every 4, 6 or 8 weeks for a further 24 weeks (phase 2). Hormone levels, patient-reported outcomes and adverse events were assessed. Primary endpoint: proportion of patients on 6- or 8-week EDIs with normal IGF1 levels at week 48 (study end). Results: 107/124 patients completed the study (15 withdrew from phase 1 and two from phase 2). Of 124 patients enrolled, 77.4% were allocated to 6- or 8-week EDIs in phase 2 and 75.8% (95% CI: 68.3-83.3) had normal IGF1 levels at week 48 with the EDI (primary analysis). A total of 88.7% (83.1-94.3) had normal IGF1 levels after 24 weeks with 6-weekly dosing. GH levels were ≤2.5 mg/l in >90% of patients after 24 and 48 weeks. Patient preferences for lanreotide Autogel 120 mg every 4, 6 or 8 weeks over octreotide LAR every 4 weeks were high. Conclusions: Patients with acromegaly achieving biochemical control with octreotide LAR 10 or 20 mg/4 weeks are possible candidates for lanreotide Autogel 120 mg EDIs. EDIs are effective and well received among such patients

Power-Law Scaling in the Internal Variability of Cumulus Cloud Size Distributions due to Subsampling and Spatial Organization

In this study, the spatial structure of cumulus cloud populations is investigated using three-dimensional snapshots from large-domain LES experiments. The aim is to understand and quantify the internal variability in cloud size distributions due to subsampling effects and spatial organization. A set of idealized shallow cumulus cases is selected with varying degrees of spatial organization, including a slowly organizing marine precipitating case and five more quickly organizing diurnal cases over land. A subdomain analysis is applied, yielding cloud number distributions at sample sizes ranging from severely undersampled to nearly complete. A strong power-law scaling is found in the relation between cloud number variability and subdomain size, reflecting an inverse linear relation. Scaling subdomain size by cloud size yields a data collapse across time points and cases, highlighting the role played by cloud spacing in controlling the stochastic variability. Spatial organization acts on top of this baseline model by increasing the maximum cloud size and by enhancing the variability in the number of smallest clouds. This reflects that the smaller clouds start to live on top of larger-scale thermodynamic structures, such as cold pools, which favor or inhibit their formation. Compositing all continental cumulus cases suggests the existence of a prototype diurnal time dependence in the spatial organization. A simple stochastic expression for cloud number variability is proposed that is formulated in terms of two dimensionless groups, which allows objective estimation of the degree of spatial organization in simulated and observed cumulus cloud populations

Gaze–mouse coordinated movements and dependency with coordination demands in tracing.

Eye movements have been shown to lead hand movements in tracing tasks where subjects have to move their fingers along a predefined trace. The question remained, whether the leading relationship was similar when tracing with a pointing device, such as a mouse; more importantly, whether tasks that required more or less gaze–mouse coordination would introduce variation in this pattern of behaviour, in terms of both spatial and temporal leading of gaze position to mouse movement. A three-level gaze–mouse coordination demand paradigm was developed to address these questions. A substantial dataset of 1350 trials was collected and analysed. The linear correlation of gaze–mouse movements, the statistical distribution of the lead time, as well as the lead distance between gaze and mouse cursor positions were all considered, and we proposed a new method to quantify lead time in gaze–mouse coordination. The results supported and extended previous empirical findings that gaze often led mouse movements. We found that the gaze–mouse coordination demands of the task were positively correlated to the gaze lead, both spatially and temporally. However, the mouse movements were synchronised with or led gaze in the simple straight line condition, which demanded the least gaze–mouse coordination

Modeled contrast in the response of the surface energy balance to heat waves for forest and grassland

Observations have shown that differences in surface energy fluxes over grasslands and forests are amplified during heat waves. The role of land-atmosphere feedbacks in this process is still uncertain. In this study, a single-column model (SCM) is used to investigate the difference between forest and grassland in their energy response to heat waves. Three simulations for the period 2005-11 were carried out: a control run using vegetation characteristics for Cabauw (the Netherlands), a run where the vegetation is changed to 100% forest, and a run with 100% short grass as vegetation. A surface evaporation tendency equation is used to analyze the impact of the land-atmosphere feedbacks on evapotranspiration and sensible heat release under normal summer and heat wave conditions with excessive shortwave radiation. Land-atmosphere feedbacks modify the contrast in surface energy fluxes between forest and grass, particularly during heat wave conditions. The surface resistance feedback has the largest positive impact, while boundary layer feedbacks generally tend to reduce the contrast. Overall, forests give higher air temperatures and drier atmospheres during heat waves. In offline land surface model simulations, the difference between forest and grassland during heat waves cannot be diagnosed adequately owing to the absence of boundary layer feedbacks

Conceptualizing pathways linking women's empowerment and prematurity in developing countries.

BackgroundGlobally, prematurity is the leading cause of death in children under the age of 5. Many efforts have focused on clinical approaches to improve the survival of premature babies. There is a need, however, to explore psychosocial, sociocultural, economic, and other factors as potential mechanisms to reduce the burden of prematurity. Women's empowerment may be a catalyst for moving the needle in this direction. The goal of this paper is to examine links between women's empowerment and prematurity in developing settings. We propose a conceptual model that shows pathways by which women's empowerment can affect prematurity and review and summarize the literature supporting the relationships we posit. We also suggest future directions for research on women's empowerment and prematurity.MethodsThe key words we used for empowerment in the search were "empowerment," "women's status," "autonomy," and "decision-making," and for prematurity we used "preterm," "premature," and "prematurity." We did not use date, language, and regional restrictions. The search was done in PubMed, Population Information Online (POPLINE), and Web of Science. We selected intervening factors-factors that could potentially mediate the relationship between empowerment and prematurity-based on reviews of the risk factors and interventions to address prematurity and the determinants of those factors.ResultsThere is limited evidence supporting a direct link between women's empowerment and prematurity. However, there is evidence linking several dimensions of empowerment to factors known to be associated with prematurity and outcomes for premature babies. Our review of the literature shows that women's empowerment may reduce prematurity by (1) preventing early marriage and promoting family planning, which will delay age at first pregnancy and increase interpregnancy intervals; (2) improving women's nutritional status; (3) reducing domestic violence and other stressors to improve psychological health; and (4) improving access to and receipt of recommended health services during pregnancy and delivery to help prevent prematurity and improve survival of premature babies.ConclusionsWomen's empowerment is an important distal factor that affects prematurity through several intervening factors. Improving women's empowerment will help prevent prematurity and improve survival of preterm babies. Research to empirically show the links between women's empowerment and prematurity is however needed

Airborne measurements of mesoscale divergence at high latitudes during HALO-(AC)3

Boundary layer cloud transformations at high latitudes play a key role for the Arctic climate and are partially controlled by large-scale dynamics such as subsidence. While measuring large-scale and mesoscale divergence on spatial scales on the order of 100 km has proven notoriously difficult, recent airborne campaigns in the subtropics have successfully applied measurement techniques using multiple dropsonde releases in circular flight patterns. In this paper, it is shown that this method can also be effectively applied at high latitudes, in spite of the considerable differences in atmospheric dynamics compared to the subtropics. To show the applicability, data collected during the airborne High Altitude and Long Range Research Aircraft–Transregional Collaborative Research Center TRR 172-Arctic Amplification: Climate Relevant Atmospheric and Surface Processes and Feedback Mechanisms [HALO–(AC)3] field campaign near Svalbard in spring 2022 were analyzed, where several flight patterns involving multiple dropsonde launches were realized by two aircraft. This study presents a first overview of the results. We find that the method indeed yields reliable estimates of mesoscale gradients in the Arctic, producing robust vertical profiles of horizontal divergence and, consequently, subsidence. Sensitivity to aspects of the method is investigated, including dependence on sampling area and the divergence calculation.</p