Background

Surgical treatment options for horses with overriding dorsal spinous processes include interspinous ligament desmotomy and partial spinous process ostectomy. The impact of spinal surgery on the three-dimensional biomechanics of the equine thoracolumbar spine and the epaxial musculature is unclear.

Objectives

To investigate the influence of interspinous ligament desmotomy and cranial wedge ostectomy on the biomechanics of the equine thoracolumbar spine and the paraspinal Musculi multifidi.

Study design

Ex-vivo experiments.

Methods

Twelve equine thoracolumbar spine specimens were mounted in a custom-made mechanical test rig. Based on computed tomographic imaging, distances between dorsal spinous processes and the spinal range of motion (lateral bending, axial rotation, flexion, extension) were compared before and after desmotomy and cranial wedge ostectomy performed at two or five surgical sites. Anatomical dissection was subsequently conducted to document surgical trauma to the Musculi multifidi following desmotomy.

Results

The distance between spinous processes in neutral position did not increase significantly after desmotomy (median preoperative = 7.2 mm, interquartile range [IQR] = 3.6 mm; median postoperative = 7.4 mm, IQR = 3.7 mm; p = 0.09), but increased significantly after ostectomy (median preoperative = 8.8 mm, IQR = 4.2 mm; median postoperative = 13 mm, IQR = 6.1 mm; p < 0.001). Both surgical procedures significantly increased the rotational spinal range of motion (p = 0.001), particularly at the level T14/T15 (median preoperative = 6.4°, IQR = 3.2°; median postoperative = 8.2°, IQR = 3.5°; increase = 28.1%; p = 0.02). Musculi multifidi injury was evident at all desmotomy sites.

Main limitations

Ex-vivo study with limited sample size.

Conclusions

Neither interspinous ligament desmotomy nor cranial wedge ostectomy resulted in an increased range of motion during flexion, extension or lateral bending but both procedures influenced the rotational component of the equine thoracolumbar spinal mobility.

The ecological state of aquatic ecosystems is systematically monitored using various bioindicators in many countries worldwide. In the European Union, freshwater biomonitoring is the central component of the EU Water Framework Directive (WFD, 2000/60/EC) and currently based on morpho-taxonomic methods. DNA metabarcoding is a novel approach to assess the ecological state fast and efficiently based on organismal DNA signatures and thereby support and upscale biomonitoring. However, compliance of metabarcoding with existing morpho-taxonomic methods must be ensured prior to official implementation. Thus, this study, co-designed by research institutions and environmental agencies, explored necessary key parameters and performed method intercalibration for the implementation of metabarcoding into WFD assessments of running waters. We focussed on benthic invertebrates as the most commonly used bioindicators. We analysed 170 invertebrate samples collected as part of the German federal state WFD routine stream biomonitoring, first via microscopic determination and then using metabarcoding. Our goals were to quantify overlap in i) taxonomic composition and ii) ecological status derived with both methods. For this purpose, we established data harmonisation measures to integrate invertebrate metabarcoding data into the official national WFD classification modules considering abundance and presence/absence data. Our results revealed a high (ca. 70 %) overlap of bioindicator taxa found with both methods. Metabarcoding identified significantly more small invertebrate taxa and detected similar proportions of the important bioindicator ‘EPT’ taxa (mayflies, stoneflies, caddisflies). Despite deviations in some detected bioindicator taxa, the derived ecological status classes were highly correlated between methods, particularly after intercalibration (R2 = 0.74, Spearman rho = 0.86). Regardless of whether we used abundance or presence/absence data, the resulting stream type classifications showed strong agreement. Thus, our study not only demonstrates the consistency of the methods for the stream types analysed but is also the first to operationalise a path to integration of metabarcoding data into the WFD assessment modules based on formal intercalibration guidelines.

The pentafluoroorthotellurate group (−OTeF5, teflate) exhibits high electron-withdrawing properties. Indeed, it is often used as a bulky substitute for fluoride due to its high chemical stability and larger size, which reduces its tendency to act as a bridging ligand. These characteristics make it a valuable ligand in synthetic chemistry, facilitating the preparation of molecular structures analogous to polymeric fluoride-based compounds. In this study, we explore the electronic structure of the teflate group by using advanced Quantum Chemical Topology (QCT) methods to better understand its bonding nature and compare its group electronegativity with that of the halogens. For that, we examine XOTeF5 systems (X = F, Cl, Br, I) and decompose X–OTeF5 interactions into classical (ionic) and exchange-correlation (covalent) contributions by using interacting quantum atoms (IQA) energy decomposition scheme. We also conduct a detailed analysis of electron distribution by utilizing the statistical framework of electron distribution functions (EDFs) and examine the electron localization function (ELF), electron density, and reduced density gradient scalar functions, as well as delocalization indices and QTAIM charges. The results show that the electron-withdrawing properties of the teflate group are comparable to those of fluorine, albeit slightly lower. Moreover, its internal bonding is primarily ionic. Additionally, we compare −OTeF5 with other O-donor groups, demonstrating that the electron-withdrawing properties within OEF5 (E = S, Se, Te) systems are nearly identical, and these groups show a higher group electronegativity than OCF3, OC(CF3)3, and OC6F5.

Reconstructing large, inflammatory maxillofacial defects using stem cell-based therapy faces challenges from adverse microenvironments, including high levels of reactive oxygen species (ROS), inadequate oxygen, and intensive inflammation. Here, inspired by the reaction mechanisms of intracellular antioxidant defense systems, we propose the de novo design of an artificial antioxidase using Ru-doped layered double hydroxide (Ru-hydroxide) for efficient redox homeostasis and maxillofacial bone regeneration. Our studies demonstrate that Ru-hydroxide consists hydroxyls-synergistic monoatomic Ru centers, which efficiently react with oxygen species and collaborate with hydroxyls for rapid proton and electron transfer, thus exhibiting efficient, broad-spectrum, and robust ROS scavenging performance. Moreover, Ru-hydroxide can effectively sustain stem cell viability and osteogenic differentiation in elevated ROS environments, modulating the inflammatory microenvironment during bone tissue regeneration in male mice. We believe this Ru-hydroxide development offers a promising avenue for designing antioxidase-like materials to treat various inflammation-associated disorders, including arthritis, diabetic wounds, enteritis, and bone fractures.

Clastic-dominated (CD-type) Zn-Pb ± Ag deposits account for significant global Zn and Pb resources. In this contribution, we describe a new Zn-Pb ± Ag deposit, Boundary Zone, recently discovered in the Macmillan Pass district, Yukon, Canada. Nine drill holes were sampled and studied using petrography, mineralogy (whole-rock and clay fraction X-ray diffractometry), and U-Pb geochronology on fluorapatite. These methods were used to develop a mineralogical paragenesis in order to constrain the timing of and controls on sulfide mineralization.

The mineralization at Boundary Zone is hosted by the Late Ordovician-Early Silurian Duo Lake and the Middle-Late Devonian Portrait Lake Formations. The discovery of mineralized Ordovician-Silurian rocks at Boundary Zone is the first time that significant stratabound mineralization has been identified in rocks of this age within the Macmillan Pass district. The premineralization stage is dominated by early diagenetic phases, including quartz, barite, pyrite, fluorapatite, and phyllosilicates. Two genetically distinct mineralization stages have been identified. Mineralization stage I comprises stratabound fine-grained sphalerite, pyrite, galena, sulfosalts, and barian mica. Mineralization stage I sulfides formed via barite replacement, nucleation on premineralization pyrite, and porosity exploitation during early biogenic silica transformation of opal-A to cryptocrystalline and microquartz in highly siliceous mudstones (up to 85 wt % quartz). The high-grade and volumetrically major mineralization stage II formed following significant hydrothermal fluid-induced brecciation and veining of the host rocks and is accompanied by silicification and siderite formation. The presence of kaolinite, pyrophyllite, quartz, and fluorapatite suggests that hydrothermal fluids were likely F rich with temperatures up to 240°C.

In one sample from the Niddery Lake Member, a discordant vein crosscuts mineralization stage I, but its paragenetic relationship with mineralization stage II could not be determined. Fluorapatite in this vein records a Middle Jurassic U-Pb age. We suggest the multiple mineralizing events at Boundary Zone formed during a prolonged period of fluid flow, spanning from diagenetic stages in the basin, possibly to periods of Cordilleran-related deformation in the Selwyn basin. These findings have significant implications for exploration strategies in the Macmillan Pass district and similar geologic settings, where biosiliceous mudstone deposition, diagenetic barite formation, and multiple hydrothermal fluid pulses are evident.

Reversible transformation of bovine leukocytes by the intracellular parasites Theileria annulata and Theileria parva is central to pathogenesis of the diseases they cause, tropical theileriosis and East Coast Fever, respectively. Parasite-dependent constitutive activation of major host transcription factors such as AP-1 (Activating Protein 1) and NF-κB (Nuclear Factor-Kappa B) sustains the transformed state. Although parasite interaction with host cell signaling pathways upstream of AP-1 have been studied, the precise contribution of Theileria encoded factors capable of modulating AP-1 transcriptional activity, and other infection-altered signaling pathways is not fully understood. We previously showed that the Ta9 protein from T. annulata (TA15705) is secreted into the host cell cytoplasm and contributes to infection-induced AP-1 transcriptional activity. The current study employed RNA-seq to investigate the ability of ectopically expressed Ta9 to modulate the gene transcription profile of a bovine macrophage cell line, BoMac. RNA-seq identified 560 (400 upregulated and 160 downregulated) differentially expressed genes. KEGG analysis predicted a high number of upregulated genes associated with carcinogenesis such as CCND1, CDKN1A, ETV4, ETV5, FLI1, FRA1, GLI2, GRO1, HCK, IL7R, MYBL1, MYCN, PIM1 and TAL1. Ta9 introduction also affected genes associated with proinflammatory processes such as cytokines, chemokines, growth factors and metalloproteinases. Enrichment analysis of differentially expressed genes revealed that Ta9 is potentially involved in activating other host cell signaling pathways in addition to those that lead to induction of AP-1. Comparing our data with data on differentially expressed BoMac genes modulated by the secreted TashAT2 factor of T. annulata identified the gene encoding the tyrosine protein kinase hematopoietic cell kinase (HCK) as common to both data sets. HCK is essential for the proliferation of T. parva-transformed B cells and herein, we demonstrate that enzymatic activity of HCK is also essential for T. annulata- and T. lestoquardi-transformed macrophage proliferation.

This study deals with the unprecedented reactivity of a [(cyclam)MnII(OTf)2] (3-cis; OTf = CF3SO3−) with O2, which, depending on the presence or absence of a hydrogen atom donor like 1-hydroxy-2,2,6,6-tetramethyl-piperidine (TEMPO-H), selectively generates di-μ-oxo Mn(III)Mn(IV) (1) or MnIV2 (2) complexes, respectively. Both dimers have been characterized by different techniques including single-crystal X-ray diffraction, X-ray absorption spectroscopy, and electron paramagnetic resonance. Oxygenation reactions carried out with labeled 18O2 and Resonance Raman spectroscopy unambiguously show that the oxygen atoms present in the MnIVMnIII dimer originate from O2. Experimental evidences are provided for a novel method of dioxygen activation involving three Mn ions or two Mn ions and TEMPO-H to generate the bis(μ-oxo)dimanganese(IV) or bis(μ-oxo) dimanganese(III, IV) cores, respectively.

Introduction: Multi-target anti-Alzheimer's disease (AD) compounds are promising leads for the development of AD modifying agents. Ionic compounds containing quaternary ammonium moiety were synthesized, and their multi-targeted anti-AD effects were examined. Methods: Imidazole derivatives containing a quaternary ammonium moiety were synthesized and evaluated for their potential anti-Alzheimer properties using computational (in silico), cellular (in vitro), and animal (in vivo) models. The inhibition kinetics of both human acetylcholinesterase (hAChE) and butyrylcholinesterase (hBuChE) were assessed. Neuroprotective effects in amyloid-beta (Aβ)-exposed PC12 cells were also examined. Furthermore, the compounds' impact on Aβ-induced memory impairment in Wistar rats was evaluated, with a detailed analysis of the underlying mechanisms. Results: Compound 5g demonstrated acceptable cytotoxicity against human cells. This compound exhibited non-competitive dual inhibition of both hAChE and hBuChE. Additionally, compound 5g mitigated the morphological changes induced by amyloid-beta (Aβ) in PC12 cells and decreased cell mortality. It exhibited anti-oxidative stress properties, evident by reduction in reactive oxygen species (ROS) production, and inhibition of lipid peroxidation. The compound also down regulated the expression of pro-inflammatory genes IL-1β and TNF-α. In vitro studies validated compound 5g's ability to inhibit lactate dehydrogenase (LDH), attenuate neuroinflammation, and prevent the autophagy-apoptosis cascade. When administered to rats with Aβ-induced memory dysfunction, compound 5g enhanced cognitive function and improved spatial memory. In the hippocampi of treated rats, there was a noted downregulation of TNF-α and NF-kB. Furthermore, compound 5g counteracted the elevated activity of AChE. Molecular modeling validated the binding of compound 5g to both steric and catalytic sites of cholinesterase enzymes. Conclusion: The novel quaternary ammonium derivative, compound 5g, demonstrated multi-target anti-AD properties, as evidenced by in silico, in vitro and in vivo studies. Behavioral assessments and molecular analyses further confirmed its therapeutic efficacy in amyloid-beta (Aβ)-challenged rats.

Emotions affect judgments and decision making. Our paper presents a study to show that incidental background emotions (i.e., emotions not related to the actual decision) influence individuals’ tax compliance attitudes and behavior. A large-scale survey of 22,220 German taxpayers and a controlled laboratory experiment provide evidence that positive background emotions reduce willingness to comply compared to aversive (negative) background emotions. The participants in our survey show less favorable tax compliance attitudes on weekends, which are usually associated with more positive background emotions. These findings are supported by the results of a controlled laboratory experiment in which background emotions were induced by standardized pictures. Individuals choose to evade taxes more often after being exposed to positive emotions than after being exposed to aversive emotions.

The recent record of extremely rare rhabdopleurid graptolites with a supposed epibiontic life style in the Fezouata biota has to be rejected, as the specimens indicate an epibenthic growth on a shell fragment lying on the sea bottom. In absence of morphological data that support a truly colonial development on these encrusters, it cannot be ruled out that the specimens may alternatively represent the pseudo-colonial tubaria of cephalodiscid-like pterobranchs. The interpretation of the presence of benthic graptolites (class Pterobranchia; subclass Graptolithina) from the Fezouata Shale biota of Morocco provides us with some serious problems. Their life style as benthic or epibenthic organisms living on firm substrates and hardgrounds makes it difficult for them to be preserved in these highly fossiliferous, originally ‘soupy’ soft sediments of the Fezouata Shale, unless they are transported and covered by sediment subsequently. The graptolite record of the Fezouata biota appears to be restricted to planktic forms of Graptoloidea: the review of the few benthic dendroids so far cited for the Lagerstätte resulted in the identification of the rare planktic dendroid genus Calyxdendrum. The problematic species Webbyites felix may represent a hydrozoan (Cnidaria) rather than a benthic graptolite.

Higher education institutions have implemented various affirmative action policies aimed at increasing the representation of female professors, including measures to reduce gender bias in professorship appointments. This raises the question of whether gender bias still exists. Research on gender bias in assistant professor appointments remains sparse. We therefore examine whether gender bias in assistant professor recruitment exists and differs across disciplines (looking at mathematics/physics, economics/sociology/political science, and German studies). Our analysis is based on a factorial survey experiment with 1857 professors from German universities in 2020. We draw on Crandall and Eshleman's (2003) justification-suppression model to argue that gender policies can help suppress the expression of prejudices (negative stereotypes) against female applicants. Our results show that in all disciplines studied, female applicants receive higher ratings than male applicants, both for perceived qualification for an assistant professorship and for being invited for an interview. The female advantage is more pronounced in mathematics/physics when applicants are perceived to be equally qualified, suggesting a greater normative pressure to comply with gender-based preferential selection. In mathematics/physics, however, we also find a smaller premium for having received a research grant among female applicants. Overall, the observed female advantage is rather small in all disciplines studied.

Analytical thin layer chromatography (TLC) is a simple yet powerful chromatographic technique that is widely used for the qualitative characterization of complex mixtures such as plant extracts. For their qualitative and visual characterisation, a large number of more or less specific colour reactions are at hand and numerous reference substances are available as well. However, the identification of extract components by colour and the comparison of retention times is not straightforward. In contrast, the coupling of TLC with MALDI-TOF mass spectrometry can enable the identification of components and contribute to the optimization of TLC protocols. One of the most important steps for a successful TLC-MALDI process is the deposition of a sufficient amount of matrix onto the TLC plate. Standard methods such as the dip-coating protocol have major drawbacks. Here we present an improved and robust procedure for matrix application by means of matrix lines. The practicability of the method was tested on plant extracts from Agrostemma githago L. and Papaver somniferum L. (opium).

In the early 1990s we met as postdocs in Cambridge just after finishing our PhDs in geophysics and geochemistry. We engaged in an informal discussion on lithospheric mantle melting in convergent orogens that was guided by two questions: (1) how can plutons have a mantle source signature in cold convergence zones; and (2) be located in the downgoing plate? The ‘slab breakoff’ hypothesis emerged. Here we review from our personal perspective how the idea was originally developed. We then provide our view looking back from our role as spectators, given that we have left the topic after the design of the hypothesis.

1. Plant invasions pose a major threat to terrestrial biodiversity, and microplastic pollution in soil could exacerbate this problem. Seed germination, a crucial stage for plants, can be affected by microplastics through both physical interference of plastic particles and chemical leaching from plastic additives. 2. We conducted a greenhouse experiment using native and invasive plant species of European grasslands, and evaluated individual and combined effects of plastic particles and additives on germination parameters. 3. We found that plastic particles primarily affected seed germination as physical agents, while additives from these particles exerted a comparatively lesser impact. 4. Particles negatively affected seed germination of all native species. Germination velocity, synchrony and total germination decreased by ~30%, ~11% and ~11%, respectively, in soils containing plastic particles compared to those without. Certain species were negatively affected by plastic additives. For Achillea millefolium and Dactylis glomerata, germination velocity and total germination decreased by ~26% and ~7%, respectively, while germination synchrony of Dactylis glomerata decreased by ~21% in soils with additives than without them. Plastic particles may have blocked seed pores and inhibited hypocotyl and radicle growth, while toxic compounds from additives may have disrupted key germination processes. 5. By contrast, particles and additives generally did not affect invasive species, suggesting that the negative effects of plastic experienced by natives, whether physical or chemical, were counteracted by effects resulting from the novel conditions created by microplastics, which may include the amelioration of soil physical properties such as increased soil porosity and aeration, and potential positive plant–soil feedbacks. Invasive species may profit from windows of variable resource availability, with positive effects on seed germination. 6. Synthesis. Plastic particles and additives may promote plant invasion by negatively affecting seed germination of native species while having neutral effects on invasive species. The delayed germination of natives due to microplastics poses a potential threat, leading to competitive disadvantages, reduced reproductive success and increased vulnerability to invasive species. Microplastic pollution appears to favour invasive species over natives during the early stages of seed germination, highlighting that the negative effect of microplastics on terrestrial ecosystems may be more severe than previously thought.

Helen Pfeifer’s Empire of Salons employs the tools of intellectual and social history to analyze the role that salons played in the integration of the Arabic-speaking lands into the Ottoman Empire. Based primarily on Arabic and Ottoman Turkish sources, Pfeifer uses the figure of the Damascus-based scholar Badr al-Dīn al-Ghazzī (1499-1577) and the members of his family and network to demonstrate that salons were of central importance to both Arabs and Rumis as they navigated the new, post-conquest realities of the 16th century.

The fluorination of the peri-substituted acenaphthyl scaffolds 5-PhE-Ace-6-PPh2 (1E, E=O, S, Se, Te) using XeF2 afforded the difluorinated products 5-PhE-Ace-6-PF2Ph2 (2E, E=O, S, Se, Te) and tetrafluorinated products 5-PhEF2-Ace-6-PF2Ph2 (3E, E=Se, Te) depending on the stoichiometry applied. Fluoride abstraction of 2E using Me3SiOTf gave rise to the chalcogenide supported fluorophosphonium ions [5-PhE-Ace-6-P(F)Ph2](OTf) (4O and 5E, E=S, Se, Te). The molecular structure of 4O features a tetrahedral P atom, whereas those of the heavier analogues (5E, E=S, Se) contain trigonal bipyramidal P atoms that arise from intramolecular LP(E)→σ*(P−F) interactions.

The study addresses the utilization of food waste by-products from faba bean (Vicia faba L.) pods (FBP) as an alternative feed supplement to promote sustainable piglet growth by reducing antimicrobial use. Objectives include evaluation of FBP in terms of nutritional components (proximate composition, fibres, minerals), phytochemical composition (total phenols, HPLC-MS profiling), and in vitro biological activities. Air-dried FBP from the cultivar ‘Bizon’ contained high levels of crude protein (144 g/kg), dietary fibre (413 g/kg), potassium (27.8 g/kg), and iron (126 mg/kg). Phytochemical analysis of methanolic extract from FBP revealed significant levels of polyphenols, including vestitol, piscidic acid, hydroxyeucomic acid, quercetin, and kaempferol glycosides with no detectable tannins. The extract showed negligible activity against porcine digestive enzymes (α-amylase, lipase, and trypsin) (IC50 > 4 mg/mL) and demonstrated a dose-dependent antibacterial activity against Escherichia coli and Salmonella enterica in concentrations of 1–8 mg/mL. The extract had low cytotoxicity (IC50 = 432.6 µg/mL) against IPEC-J2 – cells derived from porcine jejunal epithelium. The results indicate that FBP ‘Bizon’ is a valuable source of bioactive compounds with antibacterial properties, without adverse effects on porcine enzymes or IPEC-J2 cells, supporting its potential as a sustainable feed in piglet nutrition, in line with circular economy concepts.

Since water is both a product and a common reactant impurity in the (partial) methanol oxidation to methyl formate (MeFo) on gold, its effect on the isothermal selectivity to methyl formate was investigated under well-defined single-collision conditions employing pulsed molecular beam experiments and in situ IRAS measurements. Both a flat Au(111) and a stepped Au(332) surface were used as model catalysts to elucidate how water affects the reactivity of low-coordinated step sites as compared to (111) terrace sites employing a range of reaction conditions. The interactions of water with methanol/methoxy as well as with oxygen species are addressed. Theoretical calculations, including static DFT and ab initio molecular dynamics (AIMD) simulations, are employed to enhance the microscopic understanding of water-induced changes in the oxygen species and overoxidation reactivity on gold, which are essential for the selectivity. The results provide not only information on conditions that mitigate the generally negative effect of water on methyl formate formation but also atomic-level insights into water-induced changes in the complex reaction network that governs the reactivity in applied gold catalysts, such as nanoporous gold.

Background: Results on parental burden during the COVID-19 pandemic are predominantly available from nonrepresentative samples. Although sample selection can significantly influence results, the effects of sampling strategies have been largely underexplored.

Objective: This study aimed to investigate how sampling strategy may impact study results. Specifically, we aimed to (1) investigate if outcomes on parental health and child maltreatment during the COVID-19 pandemic from a convenience sample differ from those of a specific representative sample and (2) investigate reasons for differences in the results.

Methods: In 2020, we simultaneously conducted 2 studies: (1) a web-based survey using a convenience sample of 4967 parents of underage children, primarily recruited via social media, and (2) a study using a quota sample representative of the German adult population with underage children (N=1024), recruited through a combination of telephone interviews and computer-assisted web interviews. In both studies, the same questionnaire was used. To evaluate the impact of sampling, we compared the results on outcomes (parental stress, subjective health, parental mental health, general stress, pandemic-related stress, and the occurrence of child maltreatment) between the 2 samples. To explain differences in the results between the 2 studies, we controlled for sociodemographic data, parent-related risk factors, and COVID-19–related experiences.

Results: Compared to parents from the quota sample, parents from the convenience sample reported significantly more parental stress (η2=0.024); decreased subjective health (η2=0.016); more anxiety and depression symptoms (η2=0.055); more general stress (η2=0.044); more occurrences of verbal emotional abuse (VEA; φ=0.12), witnessing domestic violence (WDV; φ=0.13), nonverbal emotional abuse (NEA; φ=0.03), physical abuse (φ=0.10), and emotional neglect (φ=0.06); and an increase of child maltreatment (VEA: exp(B)=2.95; WDV: exp(B)=3.19; NEA: exp(B)=1.65). Sociodemographic data, parent-related risk factors, and COVID-19–related experiences explained the differences in parental stress (remaining difference between samples after controlling for covariates: η2=0.002) and subjective health (remaining difference between samples after controlling for covariates: η2=0.004) and partially explained differences in parental mental health (remaining: η2=0.016), general stress (remaining: η2=0.014), and child maltreatment (remaining: VEA: exp(B)=2.05 and WDV: exp(B)=2.02) between the 2 samples. The covariates could not explain the difference in NEA (exp(B)=1.70). We discuss further factors that may explain the unexplained differences.

Conclusions: Results of studies can be heavily impacted by the sampling strategy. Scientists are advised to collect relevant explaining variables (covariates) that are possibly related to sample selection and the outcome under investigation. This approach enables us to identify the individuals to whom the results apply and to combine findings from different studies. Furthermore, if data on the distribution of these explanatory variables in the population are available, it becomes possible to adjust for sample selection bias. J Med Internet Res 2025;27:e52043

doi:10.2196/52043