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Sexual violence and risk markers in othered sexual and migrant minorities in Belgium
No full textPrevious international sexual violence research has shown that certain populations – such as migrants, applicants for international protection (AIPs), and refugees (MARs) and sexual and gender minorities (SGM) – are more at risk for sexual victimisation than others. From this evidence base, we learned that these population may have risk markers for sexual victimisation in common. In addition, the literature indicates that the increased risk for (sexual) violence exposure observed in minority groups may be explained by their exposure to stigma, prejudice, and discrimination and the ensuing othering-based stress.
Objectives: The general objective of this study is to contribute first to a better understanding of the mechanisms, nature, prevalence, and impact of sexual victimisation in MARs, SGM and persons who identify as belonging to a minority group in Belgium and their associated help-seeking behaviour upon sexual victimisation. Second, this PhD research explores the relationship between sexual victimisation, belonging to one or more minority group(s) in Belgium, and othering-based stress.
Methods: Based on the UN-MENAMAIS project, a mixed-methods methodology was applied. A critical interpretive synthesis was combined with a survey on sexual victimisation in a nationally representative sample (n = 4,632) and a randomly selected sample of applicants for international protection (AIPS) (n=62), and with in-depth interviews with 51 minority victims of sexual violence. In addition, we discussed our findings with professionals and policy makers during the Café Dialogue focus groups to formulate recommendations on prevention, care, policies, and research.
Results: In this mixed-methods PhD research, we found that minority groups in Belgium (70%) report significantly higher prevalence of sexual victimisation than majority groups (62%). More specifically, the occurrence of sexual victimisation in AIPs (84%) and LGB+ (78%) persons is very high and they report specific help-seeking barriers that may be linked to experiencing othering-based stress. Furthermore, in this thesis we also found that the mere fact of identifying oneself as belonging to a minority group is insufficient to explain the observed differences in sexual violence exposure. Yet, identifying with multiple minority statuses did serve as a sexual victimisation risk marker. In addition, identifying as LGB+ was not found to be a predictor of sexual victimisation. However, besides the identified unique risk markers for sexual victimisation in othered minorities, the variability in observed victimisation between minority and majority groups was explained by sociodemographic characteristics, a higher numbers of sexual partners, mental health status, and coping mechanisms, which show different patterns in minorities and majorities, but are of high predictive value in victims of sexual violence regardless of minority status.
Conclusion: We conclude from these findings that in order to understand the underlying mechanisms to the increased vulnerability for sexual victimisation of othered minorities, researchers and policy makers should focus on both the risk markers minorities have in common with each other and those they share with majorities as well as the risk markers that are unique to specific minority groups when designing research, prevention, and care strategies with the ultimate goal of reducing the high prevalence of sexual victimisation observed in minorities. Focusing on both common and specific vulnerabilities in research contributes to helping policy makers allocate resources to those interventions with the largest impact on societal level
A functional metagenomic pipeline for phage lysin discovery from environmental samples
No full textThe growing threat of antibiotic-resistant bacteria has intensified the need for alternative antimicrobial strategies. Phage lysins, enzymes derived from bacteriophages that break down bacterial cell walls, represent a promising new class of antibacterial agents. This study explores the discovery of novel lysins using functional metagenomics, a cultivation-independent approach that enables the identification of bioactive genes through heterologous expression and activity-based screening. We developed a comprehensive pipeline for mining viral genomes and metagenomes, consisting of: (i) partial DNA digestion with a restriction enzyme, (ii) adaptor ligation, (iii) size selection, (iv) PCR amplification, (v) a second size selection, (vi) cloning into a bi-directional expression vector, and (vii) muralytic activity screening. This workflow enabled the construction of genomic libraries and was validated by the identification of four lysins from Enterococcus phage AQEF5 and Escherichia phage λ. When applied to metagenomic libraries, sampled from sewage and pig feces, the pipeline yielded four more lysins, active against E. coli, E. faecalis, or both. Our findings highlight the effectiveness of this pipeline in uncovering novel lysins from environmental samples, offering a valuable tool to fill the discovery pipeline in the ongoing battle against antibiotic resistance
Timing matters! Using delayed signaling to improve experiential learning in procedural VR training
No full text‘Learning by doing’, or experiential learning, is increasingly implemented through immersive media such as virtual reality (VR) across domains like education and professional training. Immersive technologies enable dynamic instruction and guidance, but this potential remains underexplored. To support learning, cognitive load theory promotes signaling to reduce cognitive load by guiding attention to essential content, while discovery learning encourages minimal guidance to foster exploration. While the temporal aspect of the signaling principle is underrepresented in literature, this study suggests that striking a balance between the theoretical approaches is possible by delaying additional guidance. This work therefore investigates the impact of delayed signaling on experiential learning in VR, using a VR training module on electrofusion welding that is currently used in industry. When comparing performance after training either with immediate or delayed signaling, the data suggested improved procedural learning when signaling was delayed, with an average improvement of 8% in task completion time (p < .05, d = .76). Furthermore, the method with delayed signaling did not increase cognitive load, as measured by self-reports, suggesting that discovery learning in combination with (delayed) guidance does not place undue cognitive demand on participants. The findings stress the – currently underexposed – importance of timing of visual aids through signaling and how they can be used to optimize training effectiveness. The results are interpreted in light of existing learning literature with future directions for adaptive training systems highlighted
Scaling up the Capitalocene : paratexts, storyworld, and climate change in New York 2140
No full textIn response to the representational challenges that climate change poses to narrative, econarratology seeks to forge chains between the storyworld and broader extranarrative contexts. This article argues that paratexts, serving as a liminal zone mediating between the inside and the outside of the text, are well-suited to grappling with the scalar complexity of climate change by expanding the parameters of the storyworld to scale up narrative time and space and by complicating the author–text–reader collectivity. Using New York 2140 (2017) as a case study, the article illustrates how the interplay between the epigraphs and the core text of this novel can foster a collective subject position that evokes readerly engagement and contribute to a scalar extension, which I analyze in dialogue with the spatio-temporal scale compression underlying capitalism’s expansion, particularly drawn from ideas of David Harvey. By including the paratextual dimensions within the ambit of the storyworld of climate change texts, the article helps to extend the purview of what it means for a novel to engage with the trans-scalar collectivity in the Anthropocene
Are we on the same wavelength? Social interaction between individuals with Autism Spectrum Disorder
No full textPesticide risk indicator development for solitary bee species (Osmia spp.)
No full textPesticides are widely used in fruit orchards in Flanders (Belgium). Nonetheless, in the context of Integrated Pest Management (IPM), farmers are advised to restrict the use of pesticides. Alternative strategies to protects crops from pests, diseases and weeds are being used increasingly. However, pesticide residues could still pose a threat to beneficial organisms, such as pollinators. The introductory Chapter 1 takes a closer look at what pesticides are, how risk assessments are conducted on a European level, and the IPM situation in Flemish fruit orchards.
In 2018, at the start of this research, it was not well known which pesticide residues were present in IPM orchards. The environmental characterization of fruit orchards and their contamination, is the subject of Chapter 2. The first main research objective of the doctoral thesis was to elucidate pesticide contamination in fruit orchards. Pesticide concentration in ecologically relevant environmental compartments (topsoil, orchard flora, Osmia-collected pollen and their nesting material) was measured. Non-target organisms (NTOs) with potential pesticide exposure in a fruit orchard are soil-dwelling organisms (for example Arthropoda and Annelida) and wild and managed pollinators (such as solitary bees, bumble bees and honey bees). Therefore, risk assessments were conducted, based on data gathered during the monitoring campaign. Especially pollinators play a crucial role in fruit orchards, both ecologically and economically, precisely because they proved the ecosystem service pollination. The safety of solitary bees raised a lot of concern in Europe. European regulatory testing is still largely performed with the eusocial honey bee (Apis mellifera). However, it is recognized that only one standard test organism in toxicity testing, representing all pollinators, is insufficient. With this in mind, a risk assessment tool was developed for solitary bees: a pesticide risk indicator.
In 2018 and 2019, the aforementioned environmental compartments were sampled in ten sweet cherry (Prunus avium) and eight apple (Malus domestica) orchards. Solitary bee trap nests were provided in each fruit orchard, allowing for continuous pollen sample collection. In these bee trap
nests, solitary bees from the genus Osmia make their nest. In spring, female Osmia spp. collect pollen. They stockpile pollen provisions in the nest, on which they lay an egg, containing a bee larva. A few days later, the larva hatches and start consuming the pollen provision, whereby it develops in about thirty days into a prepupa. The prepupa starts spinning a cocoon and pupation occurs under natural circumstances in September. The adult bee overwinters in a diapausal state (hibernation) in the cocoon, and it is only when temperatures rise (March-April), that the adult bee emerges. The adult bee chews its way through the cocoon and the nesting material, and the life cycle can start all over again.
The second main research objective of the doctoral thesis, was to perform a risk assessment of pesticide residues in topsoil. This was demonstrated in detail in Chapter 3. This chapter might seem a bit odd, because it is not about solitary bees. However, the aboveground-nesting Osmia spp. come into contact with topsoil as well. They use mud to build small walls (hence mason bees) in the nest to separate the different pollen provisions and larvae. It is a challenge to include this kind of exposure in a risk assessment. Above all, there are many more underground-nesting solitary bees. It is evident that these bees are potentially exposed to pesticide residues in topsoil, but it remains difficult to quantify this exposure. Nevertheless, there are bioassays to estimate the terrestrial ecotoxicity in soil. Beneficial organisms such as earthworms are being used for that reason. Hence, it was the aim of this doctoral thesis to take a look at the potential risks for soil-dwelling organisms. Risks for all approved and applied pesticides in fruit orchards were acceptable. However, there were potential unacceptable risks due to persistent residues, coming from historic use. These pesticides had already been banned for more than ten years. This signifies the importance of multi-residue screening in monitoring campaigns, so the current status of banned pesticides in the environment can be assessed as well.
The third main research objective of this doctoral thesis was to validate a toxicity test protocol (bioassay), with two solitary bee species, the European orchard bee (O. cornuta) and the red mason bee (O. bicornis). Full detail of the bioassay is explained in Chapter 4. With this bioassay, it is possible to assess sublethal effects, due to chronic exposure to low concentrations of pesticides. This implies that at low pesticide concentrations, bee larvae do not immediately die, but experience adverse effects, resulting in lower survival chances and a reduced fitness. The larval stage was assumed to be the most vulnerable life stage, because it is the stage where (oral) exposure to pesticide residues is most likely, because larvae consume potentially contaminated pollen. The oral toxicity bioassay for solitary bee larvae was successfully validated in 2021 with as test chemical the neonicotinoid insecticide thiacloprid. The bioassay was immediately put to the test with field-realistic concentrations of six selected insecticides (acetamiprid, methiocarb, pirimicarb, spinosyn A, methoxyfenozide and thiacloprid).
The six aforementioned insecticides were selected, because high toxicity towards solitary bees was presumed. In this bioassay, the 90th percentiles (P90) of measured concentrations were used. The reason for that, is that the specific protection goal for pollinators, as stated by the European Food Safety Authority (EFSA), is exactly this P90 exposure. For the pollination service to be safeguarded, P90 exposure to pesticides should lead to negligible effects (both short term and long term). The bioassay could be seen as an alarm: if adverse effects are observed in a well-controlled laboratory environment, there would likely be a problem in the field as well. During the bioassay, numerous endpoints were observed or measured. The endpoints could be categorized as either acute endpoints, such as larval mortality, or chronic endpoints, such as faster or slower larval development time. Besides these two endpoints, the following endpoints were assessed as well: cocoon mass, pollen consumption, winter mortality, mass loss during overwintering, emergence time and adult longevity.
No adverse effects on both acute and chronic endpoints were recorded, even when the six pesticides were administered in a worst case mixture at the same P90 concentrations. Because no effects (compared to a negative control group) were found, the P90 concentrations are referred to in ecotoxicological terms: No Observed Effect Levels (NOEL). Further testing these insecticides in a dose-response experimental set up (multiple increasing concentrations of the same pesticide) remains necessary in order to refine the obtained NOEL values. From which point onwards (which higher concentration) would the risk be unacceptable?
The fourth main research objective of the doctoral thesis was the development of a pesticide risk indicator for solitary bees. This was illustrated in Chapter 5. One of the constraints of performing a risk assessment for solitary bees, is the lack of toxicological endpoints. There were very few (adult bees) to none (bee larvae) endpoints available in the scientific literature for solitary bees. Although Europe recognizes the importance of solitary bees and bumble bees (Bombus spp.) in regulatory risk assessment of pesticides, thé standard test organism remains the honey bee (Apis mellifera). There is a wide consensus regarding the exposure route variability between bee species and their sensitivity towards pesticides.
A theoretical risk assessment was performed, based on the developed NOEL values for the six selected insecticides. In other words, the newly developed pesticide risk indicator was applied. Briefly, a pesticide risk indicator is a ratio between for example P90 exposure and a Predicted No Effect Level (PNEL). If this ratio is higher than 1, unacceptable risk cannot be excluded. Firstly, exposure is a function of both concentration (µg pesticide per kg pollen) and consumption (kg pollen) (pollen consumption of Osmia spp. was measured as well in this research). Secondly, the derivation of PNEC values (for all solitary bees) from NOEL values (obtained from a bioassay with Osmia spp.) is not straightforward. EFSA assumes that a safety factor of 5 is sufficient to take into account inter-laboratory variability: PNECsolitary bee = NOECOsmia spp./5. By contrast, when honey bee-derived endpoints are used, EFSA recommends an additional safety factor of 10, for taking into consideration the extrapolation from one species to another: PNECsolitary bee = NOEChoney bee/50.
The pesticide risk indicator was used for the risk assessment of the six selected insecticides, and an additional three pesticides, of which honey bee endpoints, were available in literature. These pesticides were the fungicides boscalid and pyrimethanil, approved for use in fruit orchards and also frequently detected in Osmia-collected pollen. The third one was the herbicide linuron, which had an approval for use in fruit cultivation up to 2018. Pesticide residues of linuron were also frequently found in pollen samples. The pesticide risk indicator showed that there was a potential risk due to methiocarb, pirimicarb, thiacloprid and pyrimethanil. For these substances it is highly recommended to perform the larval oral toxicity bioassay for Osmia spp. in a dose-response experimental set-up. This could lead to a less conservative (higher) estimate of the NOEL values. If risks are still unacceptably high, risk assessment should be even more refined, and possibly risk mitigation measures should be put in place.
Finally, a theoretical approach for mixture toxicity risk assessment was showcased. The concept of concentration addition was hereby adopted, a frequently used concept in other domains of ecotoxicological risk assessment. With a method, called the copula method, it was taken into account that pesticide residues do not occur independently in the environment. The combination of these two has never been done, according to the author, in a risk assessment for solitary bees. The theoretical mixture of nine pesticides (of which toxicological endpoints were available) was potentially not safe for solitary bees. The same pesticides as before (as single components) contributed the most to the mixture toxicity. Reason for this: again the probably too conservative estimate of the NOEL values. The only way to refine the risk assessment, is, as was stated before, performing dose-response experiments with the potentially problematic pesticides.
The concluding Chapter 6 concisely provides insight into how all research objectives were met. Of course, answering research questions gives rise to new research questions. Future perspectives are given on how solitary bee risk assessment research should evolve and how this doctoral thesis can be of use
Towards an integrated pest management in quinoa in traditional and new production zones of Peru
No full textMeta data enrichment for improving the quality and usability of botanical collections
No full textSinds het begin van de jaren negentig hebben bibliotheken en botanische tuinen regelmatig digitaliseringsinitiatieven uitgevoerd van herbariaboeken en wetenschappelijke bronnen met als doel dergelijke collecties te restaureren en te bewaren. Het stijgende aantal gedigitaliseerde herbariumbladen biedt ook de mogelijkheid om computergebaseerde beeldverwerkingstechnieken, zoals deep learning, toe te passen. Dit om automatisch soorten en hogere taxa te identificeren, of andere nuttige informatie uit de herbariumbladen te halen zoals handgeschreven tekst en streepjescodes. Daarom stellen we in dit werk een werkwijze voor om plantenspecimens in herbaria automatisch te lokaliseren. Het online beschikbaar maken van de specimens met de bijbehorende gegevens en het samenvoegen van gegevens van verschillende instellingen maakt domeinoverschrijdend onderzoek en analyse mogelijk. De collecties worden vaak vermeld in een lange lijst die het zoek- en leerproces vervelend maakt. Een soortgelijke situatie is ook te zien bij kunst waar veel informatieve details in het werk dikwijls over het hoofd gezien worden. Het verrijken van schilderijen met planteninformatie opent de mogelijkheid om plantencollecties te koppelen aan kunstwerken waardoor beide domeinen gelijktijdig verkend kunnen worden. In dit werk wordt een werkwijze voorgesteld en gedemonstreerd aan de hand van Het Lam Gods waarbij meerdere collecties met elkaar verbonden en geïntegreerd worden
Engineering covalent organic frameworks as photocatalysts for chemical transformations
No full textEnglish summary
Covalent organic frameworks (COFs) are an emerging category of organic
polymers with highly porous crystalline structures and have a synthesis mechanism
comparable to that of metal-organic frameworks (MOFs) affording materials with a
well-defined topology and pore structure. They offer positional control over their
building blocks in two and three dimensions. This control enables the synthesis of
rigid porous structures with high regularity and the ability to fine-tune the chemical
and physical properties of the network. Due to the large surface area, easy
functionalization of the monomers, the possibility of post-synthetic modification,
and their highly ordered and crystalline structure, they are reported to be excellent
heterogeneous photocatalysts for visible-light-driven chemical transformations.
Nonetheless, they are still relatively new materials and show a lot of potential in
terms of structural design and advanced application. In this thesis, some novel COFs
were designed and synthesized and advancements have been applied as efficient
heterogeneous photocatalysts for visible-light-driven organic transformations.
Chapter 1 provides a general overview of COFs and delineates how the COFs
are unique compared to other porous organic materials. From a design perspective,
the reader will be introduced to different topologies, various linkages, synthetic
approaches, and functionalization strategies for building crystalline porous COFs
materials.
Chapter 2 provided a comprehensive and systematic overview of COF-based
photocatalysts for organic transformations subdivided according to the type of
reactions. The first section discusses the photophysical properties of COF-based
photocatalysts and the photophysical characterization methods. Then, the general
photocatalytic mechanism of COF-based photocatalysts is discussed. After that, the
advantages of COF-based heterogeneous photocatalysts are presented. Next,
strategies to improve the photocatalytic efficiency of COF-based photocatalysts are
summarized. And then as the main body, advanced examples of COF-based
photocatalysts for organic transformation are analyzed concerning the underlying
mechanisms. Subsequently, a brief perspective on the challenges and prospects for
the further development of COF-based photocatalysts is proposed. Finally, the
objective of this thesis is presented.
In Chapter 3, a new photosensitive triazine-based COF is decorated with single
Ni-sites to form a dual catalyst is described. This triazine-based COF possesses highly
crystalline, appropriately porous, suitable energy level, and widely visible light
absorption. The photoactive COF acts as the photocatalyst while the incorporated
single nickel sites act as the active transition metal species for the visible-light-driven
S-C cross-coupling reaction. The resulting COF exhibits high catalytic activity, broad
substrate adaptability, and outstanding recyclability and stability due to the ordered
structure and proximity of the photosensitizer and the nickel catalytic active sites.
The ability to incorporate single transition metal sites in a photosensitive COF
scaffold which acts as a two-component synergistic catalyst in organic
transformation is demonstrated for the first time.
Chapter 4 is presented my research that developed a novel quinoline-linked
COF-based dual catalyst via a multicomponent one-pot polymerization strategy. The
photoactive COF acts as the photocatalyst while the grafted Brønsted acid act as the
acid catalytic site for the visible-light-driven aerobic oxidative C-C bond cleavage of
cycloalkanones. The resulting dual catalyst exhibits high catalytic activity, broad
substrate adaptability, and outstanding recyclability and stability due to the large
surface area, permanent porosity, long-range conjugation as well as an orderly
arrangement of catalytic sites. This work not only provides an environmentally
benign and sustainable way to achieve the C-C bond cleavage of cycloketones for
distal keto ester production but also demonstrates the ability to graft Brønsted acid
catalytic sites in a photoactive COF scaffold and to form a dual catalyst to
synergistically perform organic transformations.
In Chapter 5, A general discussion and conclusion of this paper are provided
and an outlook is proposed from a personal standpoint