Biology subjects

Kam, J.

Publications and source records attributed to Kam, J..

3 recordsLinked to original sources

bioRxiv2026

Beyond rumination: an ecological momentary assessment of daily thinking patterns in maladaptive daydreaming

Maladaptive daydreaming is a form of maladaptive repetitive thought characterized by excessive, dysfunctional fantasy engagement, with notable links to psychological distress and poor well-being. Although symptoms can be reliably measured along a continuum, it remains unclear how they manifest in the phenomenological characteristics of everyday thinking, as well as which thought characteristics are unique to maladaptive daydreaming versus shared with trait rumination, a transdiagnostic manifestation of maladaptive repetitive thinking that frequently co-occurs with maladaptive daydreaming. To advance these questions, we conducted a pre-registered study using ecological momentary assessment to track the everyday thoughts of 446 young adults (aged 18 to 34) spanning a range of maladaptive daydreaming symptom severity as assessed with the 16-item Maladaptive Daydreaming Scale. Higher maladaptive daydreaming scores were associated with several poor mental health indicators, including higher trait rumination. Positive associations between maladaptive daydreaming scores and both negatively-valenced and task-unrelated thinking emerged, yet these relationships were accounted for by variance shared with rumination. Beyond rumination, higher maladaptive daydreaming scores were uniquely associated with worse mood, as well as greater internally-oriented attention, more socially-oriented thought, and greater overall thought persistence. Maladaptive daydreaming also uniquely moderated the relationship between internal orientation and social orientation, such that the positive association between internal and social thought content became stronger at higher levels of maladaptive daydreaming. Overall, these findings provide novel evidence that maladaptive daydreaming levels are linked to unique socioemotional features and restricted dynamics, beyond its overlap with general ruminative distress in everyday life. These insights suggest that clinical interventions should target immersive fantasy engagement alongside transdiagnostic maladaptive repetitive thinking.

neuroscience↗

bioRxiv2025

Mitochondrial dysfunction in Machado Joseph disease: insights from a multi-model system

Spinocerebellar ataxia type-3 (SCA3), also known as Machado Joseph disease, MJD) is a fatal, neurodegenerative disease belonging to the polyglutamine repeat disease family, caused by inheritance of an abnormal form of the ATXN3 gene, carrying a longer than usual trinucleotide repeat sequence. Within this study we explored mitochondrial function in a range of different experimental models of MJD, including transgenic zebrafish, mice and neuronal cells, to gain an understanding of mitochondrial function in the disease, and possible mechanisms of any dysfunction. Firstly, we examined the transgenic CMVMJD135 mouse model that develops impaired movement, neurodegeneration and decreased survival. We performed proteomic analysis on brain lysates extracted from a cohort of male and female WT and MJD mice, for analysis of differences in male and female mice separately. We identified that a major difference predicted by Ingenuity Pathway Analysis to be in both male and female MJD mice was related to impaired oxidative phosphorylation and mitochondrial dysfunction. We examined primary neuron cultures obtained from CMVMJD135 mice, validating the findings of the proteomic analysis, and finding changes to mitochondrial morphology, as well. We further examined a transgenic zebrafish model of MJD that expresses EGFP fused human ataxin-3 with short or long polyQ stretches (23 or 84Q, respectively) in neurons (expression driven under the elav/HuC promoter). The MJD zebrafish also exhibit altered mitochondrial electron transport chain complex protein levels, together with enhanced sensitivity to rotenone administration, which may be a valuable readout for treatment investigation studies in the future. Together, this study confirms, and extends on, the growing body of evidence suggesting that mitochondrial dysfunction plays a role in MJD, warranting investigation for therapeutic intervention.

neuroscience↗

bioRxiv2019

BaRTv1.0: an improved barley reference transcript dataset to determine accurate changes in the barley transcriptome using RNA-seq

BackgroundTime consuming computational assembly and quantification of gene expression and splicing analysis from RNA-seq data vary considerably. Recent fast non-alignment tools such as Kallisto and Salmon overcome these problems, but these tools require a high quality, comprehensive reference transcripts dataset (RTD), which are rarely available in plants.\n\nResultsA high-quality, non-redundant barley gene RTD and database (Barley Reference Transcripts - BaRTv1.0) has been generated. BaRTv1.0, was constructed from a range of tissues, cultivars and abiotic treatments and transcripts assembled and aligned to the barley cv. Morex reference genome (Mascher et al., 2017). Full-length cDNAs from the barley variety Haruna nijo (Matsumoto et al., 2011) determined transcript coverage, and high-resolution RT-PCR validated alternatively spliced (AS) transcripts of 86 genes in five different organs and tissue. These methods were used as benchmarks to select an optimal barley RTD. BaRTv1.0-Quantification of Alternatively Spliced Isoforms (QUASI) was also made to overcome inaccurate quantification due to variation in 5 and 3 UTR ends of transcripts. BaRTv1.0-QUASI was used for accurate transcript quantification of RNA-seq data of five barley organs/tissues. This analysis identified 20,972 significant differentially expressed genes, 2,791 differentially alternatively spliced genes and 2,768 transcripts with differential transcript usage.\n\nConclusionA high confidence barley reference transcript dataset consisting of 60,444 genes with 177,240 transcripts has been generated. Compared to current barley transcripts, BaRTv1.0 transcripts are generally longer, have less fragmentation and improved gene models that are well supported by splice junction reads. Precise transcript quantification using BaRTv1.0 allows routine analysis of gene expression and AS.

genomics↗