Biology subjects

Tasnim, N.

Publications and source records attributed to Tasnim, N..

8 recordsLinked to original sources

bioRxiv2026

Social attention and coordinated movement produce dissociable spectral and network changes during dyadic improvisational dance

Dance is increasingly delivered as an intervention for social and affective functioning, but a live dyadic encounter confounds several distinct ingredients - social attention, verbal engagement, coordinated movement, and in-the-moment generation - so its neural effects cannot be assigned to any one of them. We recorded dual-brain mobile EEG from adult human participants of both sexes (16 female, 2 male) and a dance instructor across six five-minute conditions that vary these ingredients independently: solitary rest, direct eye gaze, conversation, teacher-led and participant-led mirroring, and free improvisation, with concurrent head-mounted accelerometry. Referencing each condition to eye gaze - socially engaging but nearly motionless - rather than to solitary rest partitioned the response. The components proved dissociable. Nonverbal social attention alone reorganized the power spectrum, flattening the aperiodic exponent (g = -0.97) and desynchronizing alpha-band oscillations (g = -0.90), while leaving inter-regional connectivity unchanged (amplitude g = +0.15; phase g = +0.11). Verbal engagement added high-frequency amplitude coupling (g = +2.61) without further spectral change. Coordinated movement added a decrease in theta/alpha coupling involving the frontoparietal-control network (g = -0.59), the signature of an externally directed state, alongside a further spectral shift (g = -0.61). Movement-vigor covariates, corticokinematic coherence, and aperiodic-adjusted power indicated that the spectral effects were cortical rather than myogenic. Four weeks of improvisational dance training increased empathic responsiveness to others' distress relative to a movie control (g = 0.82). Coordinated social movement thus acts on the brain componentially, with mutual attention rather than motor load establishing the engaged state.

neuroscience↗

bioRxiv2026

Amplitude without phase: interpersonal movement coordination grades inter-brain coupling

Interpersonal movement coordination is a foundational feature of human sociality, scaffolding communication, affiliation, and joint action from infancy onward. Whether this behavioral coupling is accompanied by genuine coupling between brains, rather than one manufactured by shared sensory input or motion artifact, has proven difficult to establish. We recorded dual-brain EEG with synchronized head-mounted accelerometry from participant-partner dyads (16 dyads, 155 dyad-condition recordings) across six conditions grading interpersonal coordination from stillness to fully reciprocal joint movement, using improvisational dance to elicit sustained, naturalistic, gradable coordination. Windowed cross-correlation confirmed graded, partner-specific movement coordination, including a lead-lag signature that reversed with who led. Against a pseudo-dyad surrogate, inter-brain synchrony took one specific form: amplitude-envelope coupling in the high-beta and gamma bands, robust to a leakage-corrected measure, with no phase-based or slow-band coupling. Within dyads, movement synchrony predicted the strength of this amplitude coupling (standardized beta = 0.54 in gamma), an association that strengthened monotonically with frequency, held under a dyad fixed-effects estimator, and was undiminished when the amount of movement was entered into the model. Movement synchrony and inter-brain coupling also co-fluctuated within interactions, above surrogate. Two control analyses excluded the leading alternatives: the coupling was not sensorimotor rhythm-tracking, since corticokinematic coherence was present but non-localized and not movement-selective, and not a shared movement-frequency rhythm linking the brains. These results identify interpersonal movement coordination as an organizing variable for inter-brain coupling and specify that coupling as fast-band amplitude co-modulation, not phase synchrony. Brains couple when bodies coordinate, not when they merely move together.

neuroscience↗

bioRxiv2026

The Choreography of Coupled Brains: Coordinated Movement and Multi-Scale Neural Synchrony in Musical Theater for Individuals with Developmental Disabilities

Performing together, which demands moving, singing, and coordinating in real time, is among the most social things people do, yet whether such coordination synchronizes not only behavior but brain activity, within and between performers, has rarely been examined during genuine performance. In this pilot study, we used mobile electroencephalography, including dual-brain hyperscanning of co-performing partners, to resolve neural change over a 16-week musical-theater program in adolescents and adults with developmental disabilities, the majority autistic. We examined four levels: behavior, spectral power, within-brain (source-space) connectivity, and between-brain synchrony, framing all estimates as effect sizes. Anxiety decreased from pre- to post-intervention, consistently across participant and parent reports. During performance, high-beta and gamma power and within-brain amplitude connectivity rose broadly across the cortex, with maximal effects seen in parieto-occipital regions. Between-brain coupling was similarly carried by amplitude co-fluctuation rather than phase; however, it was graded by the degree of interpersonal movement coordination (strongest when partners mirrored one another) and scaled with movement vigor. Local and within-brain changes were thus broad and state-like, whereas coupling between brains was specific to interpersonal coordination. Coordinated movement may organize neural synchrony across scales, positioning musical theater as a tractable model for studying the social brain in motion.

neuroscience↗

bioRxiv2025

FLP-15 modulates the amplitude of body bends during locomotion in Caenorhabditis elegans

Locomotion is essential for executing most behaviours. In Caenorhabditis elegans. Efficient locomotion is exhibited as a result of the coordination of excitatory and inhibitory signals from the nervous system onto the body-wall muscles. Although neurotransmitters play a vital role in maintaining and executing coordinated movements, neuropeptides have emerged as important players in the regulation and sustenance of locomotory states. In our previous study we explored the role of the neuropeptide FLP-15 in regulating reversal frequency during foraging behaviour in C. elegans. We were also interested in exploring other possible locomotory defects in flp-15 mutant animals. In this work we show that flp-15 mutants show an increased length of reversals during foraging resulting in defects in maintaining the direction of reversals. Mutants in flp-15 exhibited a "floral" pattern of reversals as opposed to near linear patterns of reversal in wild-type control animals. We further show that the defect in maintaining the direction of reversals could be due to increased amplitude of the body-bends with flp-15 mutants showing a large increase in the mean amplitude of body-bends. Our data suggests that FLP-15 partially functions through the G-protein coupled receptor (GPCR), NPR-3, to regulates the amplitude of body-bends. Finally, we show that loss of flp-15 leads to an increase in the expression of another neuropeptide, NLP-12, whose over expression has been implicated in causing increased amplitude of body-bends allowing us to speculate that the regulation of NLP-12 by FLP-15 may allow for the observed locomotory defects in flp-15 mutant animals.

neuroscience↗

bioRxiv2025

FLP-15 functions through the GPCR NPR-3 to regulate local and global search behaviours in Caenorhabditis elegans

Foraging is essential for sustenance and well-being of all organisms. The transition from well-fed to food-deprived conditions in C. elegans triggers a localized exploration of the environment characterized by frequent reorientations. However, over time the cumulative frequency of these reorientations decreases, facilitating the transition to global search behaviour. To investigate the genetic regulation of foraging in C. elegans, we conducted a screen of neuropeptide mutants and identified several candidates involved in modulating this behaviour. Among these, neuropeptide FLP-15 emerged as a key regulator of both local and global search behaviours. Our observations revealed that FLP-15 regulates the frequency and duration of reversals during foraging. Further investigation indicated that FLP-15 is expressed in and functions through the I2 pharyngeal neuron via the G-protein coupled receptor NPR-3. Mutants lacking either flp-15 or npr-3 displayed a significant decrease in reversal frequency during local search behaviours. Interestingly, unlike wild-type animals, the reversal frequency in flp-15 and npr-3 mutants did not decrease over time. This study also describes the expression pattern of NPR-3, in a subset of head neurons, predominantly comprising of dopaminergic neurons. This expression pattern highlights a potential link between neuropeptide signalling and dopaminergic modulation of behaviour. Finally, exogenous dopamine supplementation assays revealed that FLP-15 may regulate foraging by modulating dopamine transmission, highlighting a novel neuropeptide-dopamine interaction involved in the control of foraging behaviours.

neuroscience↗

bioRxiv2025

The Development of Wet Laboratory Methods for Improved Downstream Analysis of High Throughput Sequencing Data for Virus and Viroid Diagnostics of Vitis vinifera in Australian Post-Entry Quarantine

High throughput sequencing (HTS) methods are an essential tool in Australias Post-Entry Quarantine (PEQ) facility to facilitate the rapid, reliable and sensitive diagnostics of plant viruses and viroids. Small RNA sequencing (sRNAseq) for the detection of viruses and viroids has been implemented for several plant commodities in PEQ, including clonal grasses, Prunus spp., Rubus spp., and Fragaria spp., with the potential to expand to further plant genera. Currently, imported grapevine (Vitis spp.) require many PCR assays (22) which are both laborious and time consuming. In this study we compare different wet laboratory processes for Vitis vinifera ribonucleic acid (RNA) extraction, including different tissue types, tissue weights and elution volumes and their effects on detecting viruses and viroids by Illumina sRNA sequencing. Overall, our results suggest that increased RNA concentration of V. vinifera can be achieved by using cambium tissue, reducing elution volume and decreasing the tissue weight. Furthermore, when comparing sRNAseq to current PCR methods in post-entry quarantine, sRNAseq outperformed the prescribed PCRs.

molecular biology↗

bioRxiv2023

Seroprevalence of IgG Antibody against SARS-CoV-2 Nucleocapsid protein and Associated Risk Factors

Estimation of antibody development against SARS-CoV-2 is essential means for understanding the immune response against the virus. We reported IgG antibody development status against Nucleocapsid protein of the virus and compared with lifestyle (health and food habits), co-existing diseases, vaccination and COVID-19 infection status. ELISA (Enzyme Linked Immunosorbent Assay) was performed to assess IgG antibodies targeted against the Nucleocapsid protein of SARS-CoV-2 in participants (n=500). In this seroprevalence study, serological data were estimated for a period of 10 months in the participants who were aged 10 years and above. Sociodemographic and risk factors related data were collected through a written questionnaire and chi-square test was performed to determine the association with seropositivity. The overall seroprevalence of anti-SARS-CoV-2 antibodies among the study subjects was 47.8%. Estimates were highest among the participants of 21-40 years old (55.1%), and lowest in older aged (>60 years) participants (39.5%). Among the Sinopharm vaccinated individuals 81.8% had developed anti-Nucleocapsid antibody. Physical exercise and existence of comorbidities like hypertension and diabetes were the distinguishing factors between seropositive and seronegative individuals. Seropositivity rate largely varied among symptomatic (67%) and asymptomatic (33.1%) COVID-19 infected participants. The findings suggest that residents of Dhaka city had a higher prevalence of anti-nucleocapsid antibody in the second year of the pandemic. This indicates the improvement of immunological status among the population. Finally, the study emphasizes on maintaining active and healthy lifestyle to improve immunity. However, the absence of IgG antibodies in many cases of COVID-19 infected individuals suggests that antibodies wane with time. Key messagesO_LIThe overall seroprevalence of anti-Nucleocapsid IgG among the study subjects was determined to be 47.8%. C_LIO_LIAge, regular physical exercise, existence of comorbidities were the identified parameters associated with seroprevalence. C_LIO_LIThis study observed lower prevalence of Anti-Nucleocapsid antibody among asymptomatic cases of COVID-19 infected individuals compared to symptomatic cases. C_LI

immunology↗

bioRxiv2020

Choice of assemblers has a critical impact on de novo assembly of SARS-CoV-2 genome and characterizing variants

BackgroundCoronavirus Disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic following its initial emergence in China. Using next-generation sequencing technologies, a large number of SARS-CoV-2 genomes are being sequenced at an unprecedented rate and being deposited in public repositories. For the de novo assembly of the SARS-CoV-2 genomes, a myriad of assemblers is being used, although their impact on the assembly quality has not been characterized for this virus. In this study, we aim to understand the variabilities on assembly qualities due to the choice of the assemblers. ResultsWe performed 6,648 de novo assemblies of 416 SARS-CoV-2 samples using 8 different assemblers with different k-mers. We used Illumina paired-end sequencing reads and compared the genome assembly quality to that of different assemblers. We showed the choice of assemblers plays a significant role in reconstructing the SARS-CoV-2 genome. Two metagenomic assemblers e.g. MEGAHIT and metaSPAdes performed better compared to others in most of the assembly quality metrics including, recovery of a larger fraction of the genome, constructing larger contigs and higher N50, NA50 values etc. We showed that at least 09% (259/2,873) of the variants present in the assemblies between MEGAHIT and metaSPAdes are unique to the assembly methods. ConclusionOur analyses indicate the critical role of assembly methods for assembling SARS-CoV-2 genome using short reads and their impact on variant characterization. This study could help guide future studies to determine which assembler is best suited for the de novo assembly of virus genomes.

bioinformatics↗