Biology subjects

Hendriks, M.

Publications and source records attributed to Hendriks, M..

4 recordsLinked to original sources

bioRxiv2025

A TaqMan Assay That Knows Its Mite: Specific Detection of Tropilaelaps mercedesae Clade I

Tropilaelaps mercedesae (Mesostigmata: Laelapidae), an invasive mite native to Southeast Asia, is spreading rapidly due to global bee trade and climate change. Its detection in Eastern Europe raises concerns about its entry into the EU. As a notifiable parasite under EU Animal Health Law, early and reliable detection is essential. We developed a sensitive TaqMan assay targeting the cytochrome C oxidase subunit I (COI) gene, using synthetic double-stranded DNA fragments (gBlocks). This assay enables rapid, specific, and scalable detection of T. mercedesae Clade I.

molecular biology↗

bioRxiv2020

Novelty Processing Depends on Medial Temporal Lobe Structures

ObjectivesThe goal of the present study was to identify the role of the medial temporal lobe (MTL) in the detection and later processing of novelty stimuli. MethodsTwenty-one epilepsy patients with unilateral MTL resection (10 left-sided; 11 right-sided) performed an adapted visual novelty oddball task. In this task two streams of stimuli were presented on the left and right of fixation while the patients electroencephalogram was measured. Patients responded to infrequent target stimuli, while ignoring frequent standard, and infrequent novel stimuli that could appear either contra- or ipsilateral to the resected side. ResultsNovelty detection, as indexed by the N2 ERP component elicited by novels, was not affected by the MTL resections. Later processing of novels, however, as indexed by the novelty P3 ERP component, was reduced for novels presented contra-versus ipsilateral to the resected side. Target processing, as indexed by the P3b, was unaffected. ConclusionsThe current results suggest that MTL structures play a role in novelty processing, but that the novelty signal may originate from a distinct neural source.

neuroscience↗

bioRxiv2019

Corruption of the Pearson correlation coefficient by measurement error: estimation, bias, and correction under different error models

Correlation coefficients are abundantly used in the life sciences. Their use can be limited to simple exploratory analysis or to construct association networks for visualization but they are also basic ingredients for sophisticated multivariate data analysis methods. It is therefore important to have reliable estimates for correlation coefficients. In modern life sciences, comprehensive measurement techniques are used to measure metabolites, proteins, gene-expressions and other types of data. All these measurement techniques have errors. Whereas in the old days, with simple measurements, the errors were also simple, that is not the case anymore. Errors are heterogeneous, non-constant and not independent. This hampers the quality of the estimated correlation coefficients seriously. We will discuss the different types of errors as present in modern comprehensive life science data and show with theory, simulations and real-life data how these affect the correlation coefficients. We will briefly discuss ways to improve the estimation of such coefficients.

bioinformatics↗

bioRxiv2019

Social touch observation in adults with autism: intact neural representations of affective meaning but lack of embodied resonance

Humans can easily grasp the affective meaning of touch when observing social interactions. Several neural systems support this ability, including theory of mind (ToM) and somatosensory resonance systems, but it is unclear how these systems are affected in autism spectrum disorder (ASD). Individuals with ASD are characterized by impairments in social interaction and the use of (non)verbal communication such as social and reciprocal touch. The present study applies an ecologically valid stimulus set and multivoxel pattern fMRI neuroimaging to pinpoint atypicalities in the neural circuitry underlying socio-affective touch observation in adults with ASD as compared to matched neurotypical controls. The MVPA results reveal that the affective meaning of touch is well represented in the temporoparietal junction, a core ToM mentalizing area, in both groups. Conversely, only the neurotypical group hosts affective touch representations in the somatosensory cortex, not the ASD group, yielding a significant group difference. Lastly, individuals with a more positive attitude towards receiving, witnessing, and providing social touch and with a higher score on social responsivity, show more differentiated representations of the affective meaning of touch in these somatosensory areas. Together, our findings imply that individuals with ASD are able to cognitively represent the affective meaning of touch, but they lack the spontaneous embodied somatosensory resonance when observing social touch communications. Individual differences in this diminished resonance appear to be related to social touch avoidance and quantitative autism traits.\n\nSignificance StatementAutism is characterized by socio-communicative impairments, including abnormal processing of interpersonal touch. Little is known about the neural basis of atypicalities in social touch processing in autism. Here, adults with and without autism watched video clips displaying social touch interactions and judged the affective valence of the touch. Subsequently, they underwent functional magnetic resonance imaging while watching the same videos. Brain activity patterns demonstrate that adults with autism show intact cognitive understanding (i.e. \"knowing\") of observed socio-affective touch experiences but lack of embodied emotional resonance (i.e. \"feeling\"). This lack of emotional resonance is linked to social touch avoidance and quantitative autism traits. These findings highlight that the depth of experiencing the state of others is shallower in people with autism.

neuroscience↗