44197 research outputs found
Sort by
Going Dutch: Invasion pathways and current European distribution of non-native land flatworm species belonging to Geoplaninae and Bipaliinae with focus on the Netherlands
No full textNon-native land flatworms can have a negative impact on local ecosystems, due to their ferociousness in hunting earthworms or snails. Accurate knowledge on the distribution of non-native populations of land flatworms is necessary to design effective policy to control their spread across Europe. The aim of this study is to address the spatiotemportal distribution of selected species of non-native land flatworms (Geoplaninae and Bipaliinae) in the Netherlands, and provide their current distribution and introduction pathways in a pan-European perspective.
Specimens of Obama spp., Bipalium kewense and Diversibipalium multilineatum were reported across selected Dutch gardens, greenhouses, plant nurseries or garden centers. European distribution of these planarians species was reconstructed using previously published datasets and from records available on GBIF. Morphological species identification was supported by DNA barcoding using a portion of the 28S rDNA marker. Introduction pathways were addressed via haplotype networks based on COX1 mtDNA.
In total, 27 specimens of non-native land flatworms were collected in the Netherlands. Their different spatiotemporal distribution pattern indicates differences in tolerance to environmental conditions in Northern Europe between B. kewense restricted to greenhouses and D. multilineatum found in gardens. Generally, an increasing trend in the number of total records of O. nungara is observed in the Netherlands and in Europe, with the highest number of records per country reported in France (1.428) followed by the Netherlands (150) and Italy (64). The high numbers of France are however artificial and originate from communication towards the public, which has not been as pronounced in other European countries. Genetic analyses suggest multiple introductions of O. nungara in Europe. Combination of morphological and molecular species identification revealed the presence of Obama anthropophila being the first record of this species outside its native range in Brazil. Our results further support the established status of these species in Europe and highlight the importance of citizen scientists in invasive species research.NK received support from the Special Research Fund of Hasselt University 837(BOF21PD01). NK is currently funded by theBelgian Science Policy Office (BELSPO) 838(AfroWetMaP project). This study was carried out with the Belgian National Scientific 839Secretariat on Invasive Alien Species as technological partner
We are grateful to all citizens who posted findings of land flatworms on Waarneming.nl, 881or who reported their findings over the email. A special thanks to all the citizens who 882let us roam in their garden in search of land flatworms. or who took the time to collect 883the animal and send it over the mail. We thank Hugh Jones for sharing his factsheets 884on land flatworms in the United Kingdom. 885We are grateful to Maurits Waaijenberg who helped with the production of distribution 886maps
New species of groundwater Candonidae (Crustacea, Ostracoda) from Benin: towards their use as bioindicators of water quality
No full textAquatic ecosystems are currently being subjected to major transformations as a result of anthropogenic actions and the effects of climate change, with a significant impact on public health by increasing the prevalence of water-borne diseases in Africa. Monitoring of groundwater quality is therefore becoming crucial to ensure clean drinking water supplies and preserving local ecosystems. Ostracods are small and bivalved aquatic crustaceans and due to their sensitivity to environmental variations, they are considered to be reliable bioindicators, although an accurate understanding of their ecology and distribution is required. Between 2015 and 2022, ostracods were sampled from more than 200 wells distributed over four catchment areas in Benin to explore the potential of ostracods as bioindicators. Sixty species of ostracods were identified and divided into two distinct ecological groups: 36 new to science stygobitic species from the family Candonidae, marking an endemic evolutionary radiation, and 24 non-stygobitic species, mainly from the family Cyprididae. Five new species of Candonidae were described, belonging to a new genus and subfamily, characterised by distinctive features such as a sevensegmented antennule, a specific caudal ramus, and other features of carapace and hemipenis morphology. Presence of ostracods was studied as a function of predictor variables, including water quality variables and other characteristics of the wells. The results showed that factors such as electrical conductivity, pH, temperature, bicarbonate concentration and NO2- levels significantly influenced the structure of ostracod communities. Stygobitic species compared to non-stygobites were found to be particularly sensitive to high nitrite levels, highlighting their vulnerability to anthropogenic disturbance. Thus, we conclude that the new stygobitic ostracod species, show promising potential to serve as reliable bioindicators for groundwater quality in tropical West Africa.
Keywords: Freshwater Ostracoda, Africa, water quality, ecology, bioindicator
Negative radiation pressure scheme for simultaneous suppression of arduous back-action evasion and shot noise in gravitational wave detectors
No full textAiming at applications for gravitational wave (GW) detection, in particular at
the reduction of quantum back action noise, we propose a novel scheme how
to obtain back action evading measurements performed on an opto-mechanical
cavity, by introducing a negative radiation pressure coupling between the cavity field and the end mirror. The scheme consists of introducing a double cavity
with end mirrors interlocked by a pivot and moving in opposite directions. The
measurement is performed by sending a two-mode squeezed vacuum to both
cavities and detecting the output through the heterodyne detection. Compared
to the previously proposed hybrid negative mass spin-optomechanical system in Khalili and Polzik (2018 Phys. Rev. Lett. 121 031101), we see that
our scheme is capable to suppress back action noise by nearly two orders of
magnitude more in the lower frequency region. Overall, the setup has been
able to squeeze the output noise below the standard quantum limit, with more
efficiency. The scheme has also proven to be beneficial for reducing thermal
noise by a significant amount. We confirm our result by a numerical analysis
and compared it with the previous proposals (Khalili and Polzik 2018 Phys.
Rev. Lett. 121 031101)
The molecular and urban exposome signature of telomere length in early life: data-driven insights from birth cohort studies
No full textAging is a multi-factor physiological process characterized by molecular and cellular damage, functional decline and increased vulnerability to diseases and death. As one of the hallmarks of aging that are considered to contribute to the aging process, telomere attrition, the progressive and cumulative shortening of the repetitive nucleotide sequences at the end of chromosomes, occurs in age-related diseases as well as in normal aging throughout life. Aging has been extensively explored in adulthood. Nevertheless, differences in aging and developmental trajectories in early life may already set the vulnerability differences to diseases that could persist and accumulate over time. Complex interactions of cellular and biochemical processes are involved in biological aging and are reflected in the molecular profiles of various omics layers. The advent of high-throughput omics approaches enabled a global assessment of this interaction and identification of relevant biological pathways. Environmental factors contribute to the acceleration of aging processes and progression of a wide range of age-associated diseases. Early-life exposome, encompassing all environmental factors from the prenatal period to childhood, plays a critical role in
life-course aging. Yet, evidence on the environmental determinants and molecular mechanisms underlying early-life aging is scarce. In this dissertation, we aim to evaluate the omics signatures and the health effect
of exposome related to telomere length in early life, based on birth cohort data collected from mother-newborn pairs at birth and during childhood. Telomere length measured at both time points was used as an indicator of biological age of the population of the corresponding age, and telomere attrition from birth to childhood was used as a marker of biological aging. This doctoral dissertation consists of our works which fall into four chapters as summarized in Table I. In the first part, we modeled the variation in newborn telomere length and telomere attrition rate from birth to around 4 years with epigenome-wide DNA methylation profiled in cord blood at birth, considering both the first-order additive effect and two-way interactions of the methylation level at CpG loci. From 850K CpG loci, distinct epigenetic signatures were found for baseline biological age and aging
rates: 47 CpGs and 7 between-CpG interactions explained 76% of the variance
in newborn telomere length, while 72% of the total variance in telomere attrition
rate was explained by 31 CpGs and five interactions.
The second part of this dissertation focused on the potential interplay between
genetic variants and epigenome-wide DNA methylation in setting the newborn
telomere length. Starting from candidate single nucleotide polymorphisms (SNPs),
we identified 57 cis methylation quantitative trait loci, of which 22 confirmed
previous findings. Indirect effects were found in five SNPs via a mediating CpG,
and the effect of rs911874 (SOD2) was modified by nearby DNA methylation.
These findings suggested that DNA methylation in cis might have a mediation or modification effect on the genetic difference in newborn telomere length.
The investigation of omics signatures of childhood biological age was then extended
to multi-omics, including genome-wide genetic variants, epigenome-wide DNA
methylation, gene expression and mRNA transcriptome, plasma protein profile,
and serum and urine metabolites. Through omics-wide association analysis, two
CpGs (cg23686403 and cg16238918 at PARD6G gene) were identified to strongly
associate with childhood telomere length, while supervised multi-omics integration
revealed robust associations between the multi-omics signature of telomere length
and child body mass index, with metabolites and proteins emerging as the primary
contributing molecular features.
Finally, we explored the health effect in biological age reflected in childhood
telomere length of the longitudinal urban environment, including the built
environment, air pollution, noise, meteorology, natural space, and road traffic
measures that are quantified both prenatally and postnatally. We identified, via
both an exposome-wide association study and a mixture effect analysis, that
higher early-life exposure to natural spaces and land use diversity, as well as
lower exposure to the urban built environment and traffic-related factors, were
associated with longer childhood telomere length.
The findings from this dissertation prove the effectiveness of our data analysis
workflow, suggest potential novel targets of further investigation and an intricate
interplay between telomere length, metabolism and immune responses, and
provide evidence that the reductions in adverse urban exposures may promote
molecular longevity from early life onward
Molecular miscibility of ASD blend components: an evaluation of (the added value of) solid state NMR spectroscopy and relaxometry
No full textIn order to evaluate the stability of an amorphous solid dispersion (ASD) it is crucial to be able to accurately determine whether the ASD components are homogeneously mixed or not. Several solid-state analysis techniques are at the disposal of the formulation scientist, such as for example modulated differential scanning calorimetry (mDSC) and solid-state nuclear magnetic resonance spectroscopy (ssNMR). ssNMR is a robust, versatile, and accurate analysis technique with a large number of application possibilities. Especially ssNMR relaxometry, which allows the measurement of the proton relaxation times T1H and T1rH, is very useful for evaluating the miscibility of ASDs. In this paper, the miscibility of a model ASD, composed of indomethacin (IND) and poly(vinylpyrrolidone-co-vinyl acetate) (PVPVA), was assessed using mDSC and various ssNMR techniques, in order to compare the different techniques and to evaluate the advantages and disadvantages of each. It was found that measuring the relaxation times via the chemical shift selective carbon signals using 13C-cross-polarization magic angle spinning (13C-CPMAS) is still the golden standard to evaluate miscibility, even giving information about the miscibility at the nm scale. Although non-chemical shift selective 1Hwideline measurements are significantly faster than 13C-CPMAS measurements to determine the relaxation times, the results are often hard to interpret, especially with regard to the T1rH relaxation times. 2D 1H-13C dipolar heteronuclear correlation (dipolar HETCOR) NMR is an additional technique that can be used, and which provides information about the special proximity of 1H and 13C nuclei with respect to each other and therefore about the miscibility of the components at the nm scale. Additionally, it often allows to acquire information regarding the intermolecular interactions and the functional groups involved. Nevertheless, optimalization of the experiments, data processing and interpretation of the results require some expertise. Compared to mDSC, the ssNMR techniques are more sensitive and robust and can often provide information about the miscibility at nm scale. However, mDSC is a very fast analysis technique that requires less optimalization. Therefore, it remains recommended to use mDSC always for a first screening and as a complementary analysis technique. (c) 2025 American Pharmacists Association. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.This project is funded by a strategic basic research grant for L.C. from FWO Vlaanderen (Fonds voor Wetenschappelijk Onderzoek Vlaanderen) (grantnumber 1SD5524N). This work is also supported by Hasselt University and FWO Vlaanderen via the Hercules project AUHL/15/2 - GOH3816N
Een kwalitatieve studie naar de perspectieven van interprofessionele zorgteams omtrent differentiatie tussen verpleegkundige expertfuncties
No full textDOEL: Het doel van dit onderzoek was om de differentiatie tussen verpleegkundige expertfuncties in kaart te brengen, dit met een focus op verpleegkundig specialisten en verpleegkundig consulenten vanuit het perspectief van interprofessionele zorgteams in een Vlaamse ziekenhuiscontext. METHODE: Aan de hand van doelgerichte steekproeftrekking werden interprofessionele zorgteams gerekruteerd om deel te nemen aan semigestructureerde focusgroep-interviews. De volgende aspecten werden hierbij in beschouwing genomen: teamsamenstelling, type ziekenhuis, geografische locatie en beschikbaarheid. RESULTATEN: Hoewel Interprofessionele zorgteams beperkte kennis hebben over functiedifferentiatie tussen verpleegkun-dige expertfuncties, erkennen zij de toegevoegde waarde die deze functiedifferentiatie kan hebben voor zowel het team als voor de patiëntenzorg. Bovendien nemen verpleegkundig consulenten en verpleegkundig specialisten een aantal rollen op waarop zij zich differentiëren en elkaar aanvullen: opleider, coach en coördinator van zorg. Naast deze gemeenschappelijke rollen werd de wetenschappelijke rol alleen voor de verpleegkundig specialist geïdentificeerd. CONCLUSIES: De differentiatie tussen verpleegkundig consulenten en verpleegkundig specialisten stelt deze functies in staat om op een synergistische manier samen te werken, vandaar dat beide functies geïmplementeerd moeten worden om elkaars praktijkvoering aan te vullen. Hoewel interprofessionele teams beperkte kennis hebben over functiedifferentiatie in de verpleegkunde erkennen ze hiervan de meervoudige meerwaarde. TREFWOORDEN: verpleegkundig specialisten; verpleegkundig consulenten; APN; functiedifferentiatie; interprofessioneel zorgtea
Digital mapping of soil organic carbon using drone remote sensing
No full textSoil organic carbon (SOC) content is a key indicator of soil health informing about sustainable land management practices, but parcel-wide SOC mapping is challenging as it requires high-resolution data. Unoccupied Aerial Vehicles (UAVs) can collect data with cm-resolution but are not yet fully ready to be practically implemented. The aim of this study is to provide more insights in the explanatory capabilities of UAV-derived spectral and topographical variables. To this end, mixed models were employed to estimate the SOC content of three agricultural parcels with different crop types in Greece. Results showed variations in SOC content among parcels, with a vineyard and a kiwi orchard having higher values compared to a peach orchard. All models, containing topographical and/or spectral variables, explained 81% of SOC content variation of the training dataset. Besides crop type, other topographical and spectral variables were identified as significant predictors. The study emphasizes the feasibility of UAV data and specific modeling techniques for accurate SOC estimation at the parcel level, providing valuable insights for precision agriculture. The findings recommend further exploration, including machine-learning approaches in future studies
Optimizing City Logistics: Analyzing the Benefits of a City Hub by means of Integrated Inventory Routing Decisions
No full textAlthough extensive literature exists on the use of urban consolidation centers (UCC) as a solution for
urban logistics, its implementation is often not well supported by operational and tactical planning
tools. Moreover, it is likely that the efficiency and sustainability of modern urban supply chains can
be considerably improved by coordination and collaboration among supply chain actors. The sharing
of logistic resources such as transport vehicles and urban logistics space is key to reduce costs. Even
though the city is often not the main decision maker in new logistics initiatives, it can both support
the supply chain companies operating on its territory and nudge them in a sustainable direction.
Many cities struggle, however, to develop appropriate policies for the supply chain services in their
urban region.
In our research we investigate how to organize distribution activities for B2B flows in a multi-echelon
distribution system making use of a UCC. UCCs still offer new opportunities for urban B2B flows, as
they could act as an intermediate storage facility, allowing retailers to save costly storage space in
expensive commercial areas (Johansson and Björklund (2017). Only a few research efforts have
studied the integration of inventory management (i.e., store replenishment) and distribution (i.e.,
routing) decisions in such a system (e.g., De Maio and Laganà (2020)). While there is a large body of
literature on related inventory routing problems (IRPs), most of this work does not account for the
specific aspects that arise in urban areas (Archetti and Bertazzi, 2021).
Our goal is to analyze to what extent the integration of inventory and routing decisions leads to
additional operational benefits compared to a traditional setting in which the UCC is only used as a
consolidation point. To address our research question, two scenarios are considered and compared:
a traditional one in which inventory and routing decisions are taken sequentially (as in Iswari et al.,
2023) and an integrated one in which both decisions are taken simultaneously. In this second
scenario, the city hub simultaneously determines if and how many products of each type will be
delivered to the retailers every day, and the corresponding delivery routes, while ensuring sufficient
inventory at the retailers. This results in a multi-period Inventory Routing Problem (IRP) with multiple
products, time windows, a heterogeneous fleet and multiple trips.
A matheuristic algorithm is proposed to solve this integrated inventory routing problem. Our
algorithm is based on the same idea of Bertazzi et al. (2019), who first generate promising routes and
then solve a model to select both which routes to apply on which days and to define the
corresponding delivery quantities. However, as our problem is considerably different from the one of
Bertazzi et al. (2019), several changes are made. First, in our problem setting all products originate
from a single location, i.e. the city hub, thus we only consider the second and third phases of the
method of Bertazzi et al. (2019). As such, our two phase matheuristic algorithm consists of a route
generation phase and an optimization phase. Second, as we do not create customer clusters, the
route generation phase is based on solving a VRP rather than a TSP per cluster. Third, we adapt the
method to our specific problem context by extending it to a multi-product, heterogeneous, multi-trip
context with a more complex objective function that also includes holding costs, order costs, and
duration-based routing costs. Due to the increased complexity, we propose an algorithm variant in
which we solve the MILP model in the optimization phase heuristically using column generation.
An experimental setup is designed to provide insights into critical factors that impact the
implementation of the integrated inventory routing scenario. Retailer storage capacity is found to
significantly influence the cost savings achieved through integration. Although the integrated
scenario consistently yields lower costs, the potential savings of the integrated scenario decrease as
the storage capacity at retailers decreases, as there are fewer opportunities for consolidating
deliveries and achieving efficiency gains. Additionally, the order cost plays a crucial role in shaping
the cost savings obtained from this scenario. A higher order cost leads to reduced savings.
Furthermore, retailer participation in the integrated decision-making process is a critical determinant
of cost savings. Higher levels of retailer participation result in more substantial cost reductions in
both the second and first echelons. Actively involving retailers in the decision-making process allows
for better resource utilization and overall cost benefits. Finally, as the cost of organizing a city hub
may considerably offset potential savings, a sensitivity analysis of transshipment costs is also
performed. The results indicate that in specific settings, such as a high number of retailers, using the
city hub may result in minimal or no cost savings, particularly in case of high transshipment costs.
Additionally, the findings highlight that the integrated inventory routing scenario consistently
outperforms the scenario in which separate inventory and routing decisions are taken. Lower costs
per delivery point are observed across all transshipment cost ranges considered in both scenarios. As
transshipment costs increase, the cost difference becomes even larger.This study is supported by the Special Research Fund (BOF) of Hasselt University, Belgium
(BOF20OWB26) and by VLAIO cSBO project STRAUSSHBC.2023.0008. The computational resources
and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by
the Research Foundation Flanders (FWO) and the Flemish Government
Notes on semisimple tensor categories of rank two
No full textIn this paper, we show that there are infinitely many semisimple tensor (or monoidal) categories of rank two over an algebraically closed field F.This work is supported by NNSF of China (Nos. 12071412,12201545)