Biology subjects

Anwar, M. Z.

Publications and source records attributed to Anwar, M. Z..

10 recordsLinked to original sources

bioRxiv2026

Tail Flaring as an Agonistic Signal in Hummingbirds

Bird tails in flight generate lift, reduce pressure drag, and stabilize pitch. Hummingbirds can sustain hovering in still air and generate lift in both the up- and downstroke due to their proportionally enormous primary flight muscles and derived wing skeleton. Given their mass-specific wing power, it is possible that tails are less essential to the aerodynamics of hummingbird flight than they are in other birds, freeing them for non-locomotor functions. Hummingbird tails are well known for their morphological elaboration as sexually selected ornaments, including sound generation. From informal observations of agonism, we hypothesized tail flaring may also be a visual signal used by males during fighting. To begin testing this, we measured the frequency and magnitude of tail flaring during fighting. We measured kinematics of tail flaring during male-male fighting of Calliope hummingbirds (Selasphorus calliope, n = 10) indoors. Consistent with our hypothesis, captive males exhibited greater angles of tail flare when engaged in a fight (34.6 {+/-} 45.5{degrees}, mean {+/-} sd) than when performing solitary landing (-14.2 {+/-} 9.12 {degrees}) and takeoff (-14.1 {+/-} 7.0 {degrees}) maneuvers. When birds won a fight, the angles of their tail spread were greater than when they lost (p = 0.01). Moreover, recordings of seven species of hummingbird in the field revealed 95% of inter- and intra- specific contests included tail flaring. We evaluate these results in the context of signaling during animal contests and propose future tests of whether tail flaring is an honest signal of individual quality and Resource Holding Potential. Summary StatementMale-male fighting is common in hummingbirds with competition over food and mates. During these competitions, tail flaring and waggle maneuvers are used as a signal of aggressive intent.

evolutionary biology↗

bioRxiv2025

VIRUS-MVP: A framework for comprehensive surveillance of viral mutations and their functional impacts

As viruses evolve, they accumulate genetic mutations that can influence disease severity, transmissibility, and the effectiveness of vaccines and therapeutics. Real-time tracking of viral mutations and their functional impacts is essential to understand these changes and assess their implications for public health responses. VIRUS-MVP is an interactive, portable platform designed for the comprehensive surveillance of viral mutations. Initially developed for SARS-CoV-2, it now fully supports mpox and is expanding to include influenza and RSV. The platform links viral mutations to functional annotations, providing insights into their predicted effects on viral infectivity, immune evasion, and protein functionality. It features an interactive interface for visualizing mutation distributions, a modular and reproducible genomics workflow, and a curated annotation resource that captures known impacts on viral proteins and host interactions. Users can also import custom functional annotations to tailor analyses to specific research needs or emerging pathogens. Developed collaboratively with public health and academic partners, VIRUS-MVP enhances understanding of viral evolution and its public health impact by bridging genomic data with biological insights. The platform is open-source, adaptable, and accessible on GitHub.

bioinformatics↗

bioRxiv2023

Hummingbirds rapidly respond to the removal of vision and control a sequence of rate-commanded maneuvers in milliseconds

Hummingbird flight is the epitome of extreme aerial agility and controlled stability, as hummingbirds routinely exercise a variety of stunning aerobatic feats. Yet, the control of these amazing maneuvers is not well understood. Here we examined how hummingbirds control a sequence of maneuvers within milliseconds and tested whether and when their vision is active during this rapid process. We elicited escape flight in calliope hummingbirds and removed visible light at various instants during the maneuvers and quantified their flight kinematics and responses. We show that the escape maneuvers were composed of rapidly-controlled sequential modules, including evasion, reorientation, nose-down dive, forward flight, and nose-up to hover. The hummingbirds did not respond to the light removal during evasion and reorientation until a critical light-removal time; afterward they showed two categories of luminance-based responses that rapidly altered maneuvering modules to terminate the escape. We also show that hummingbird maneuvers are rate-commanded and require no active braking, i.e., their body angular velocities were proportional to the change of wing motion patterns, a trait that likely alleviates the computational demand on flight control. Together, this work uncovers the key traits of hummingbird agility, which can also inform and inspire designs for next-generation agile aerial systems.

animal behavior and cognition↗

bioRxiv2023

Concurrent stimulation of diflufenican biodegradation and changes in the active microbiome in gravel revealed by Total RNA

The use of slowly degrading pesticides poses a particular problem when these are applied to urban areas such as gravel paths. The urban gravel provides an environment very different from agricultural soils; i.e., it is both lower in carbon and microbial activity. We, therefore, endeavoured to stimulate the degradation of the pesticide diflufenican added to an urban gravel microcosm amended with dry alfalfa to increase microbial activity. In the present study, the formation of the primary diflufenican metabolite 2-[3-(Trifluoromethyl)phenoxy]nicotinic acid (commonly abbreviated as AE-B) was stimulated by the alfalfa amendment. The concurrent changes of the active microbial communities within the gravel were explored using shotgun metatranscriptomic sequencing of ribosomal RNA and messenger RNA. Our results showed, that while the active microbial communities in the gravel were dominated by bacteria with a relative abundance of 87.0 - 98.5 %, the eukaryotic groups, fungi and micro-eukaryotes, both had a 4-5 fold increase in relative abundance over time in the alfalfa amended treatment. Specifically, the relative abundance of microorganisms involved in degradation of complex carbon sources, Bacteroidetes, Verrucomicrobia, Sordariomycetes, Mortierellales, and Tremellales, were shown to increase in the alfalfa amended treatment. Further, the functional gene profile showed an increase in genes involved in increased activity and production of new biomass in the alfalfa treatment compared to the control, as well as pointing to genes potentially involved in biodegradation of complex carbon sources and the biotransformation of diflufenican.

microbiology↗

bioRxiv2022

COVID-MVP: an interactive visualization for tracking SARS-CoV-2 mutations, variants, and prevalence, enabled by curated functional annotations and portable genomics workflow

The SARS-CoV-2 pandemic has reemphasized the importance of genomic epidemiology to track the evolution of the virus, dynamics of epidemics, geographic origins, and the emerging variants. It is vital in understanding the epidemiological spread of the virus on global, national, and local scales. Several analytical (bioinformatics) resources have been developed for molecular surveillance. However, a resource that combines genetic mutations and functional annotations on the impact of these mutations has been lacking in SARS-CoV-2 genomics surveillance. COVID-MVP provides an interactive visualization application that summarizes the mutations and their prevalence in SARS-CoV-2 viral lineages and provides functional annotations from the literature curated in an ongoing effort, Pokay. COVID-MVP is a tool that can be used for routine surveillance including spatio-temporal analyses. We have powered the visualization through a scalable and reproducible genomic analysis workflow nf-ncov-voc wrapped in Nextflow. COVID-MVP allows users to interactively explore data and download summarized surveillance reports. COVID-MVP, Pokay, and nf-ncov-voc are open-source tools available under the Massachusetts Institute of Technology (MIT) and GPL-3.0 licenses. COVID-MVP source code is available at https://github.com/cidgoh/COVID-MVP and an instance is hosted at https://covidmvp.cidgoh.ca.

bioinformatics↗

bioRxiv2022

Three-dimensional actuation of hummingbird wings requires diverse effects from the primary flight muscles

Hummingbirds have evolved to hover and maneuver with exceptional flight control. This is directly enabled by their musculoskeletal system that successfully exploits the agile motion of flapping wings. Here, we reveal novel principles of hummingbird wing actuation that provide insights into the evolution and robotic emulation of hummingbird flight. We develop a functional model of hummingbird musculoskeletal system, which predicts instantaneous, three-dimensional torque produced by primary (pectoralis and supracoracoideus) and combined secondary muscles. It also reveals primary muscle contractile behavior, including stress, strain, elasticity, and work. Results show that the primary muscles (i.e., the flight "engine") function as diverse effectors, as they do not simply power the stroke, but also actively deviate and pitch the wing. The secondary muscles produce controlled-tightening effects, by acting against primary muscles in deviation and pitching. The diverse effector capacity of pectoralis is associated with the evolution of a comparatively enormous bicipital crest on humerus.

biophysics↗

bioRxiv2019

Biogeographical patterns in soil bacterial communities across the Arctic region

The considerable microbial diversity of soils, their variety and key role in biogeochemical cycling has led to growing interest in their global distribution and the impact that environmental change might have at the regional level. In the broadest study of Arctic soil bacterial communities to date, we used high-throughput DNA sequencing to investigate the bacterial diversity from 200 independent Arctic soil samples from 43 sites. We quantified the impact of spatial and environmental factors on bacterial community structure using variation partitioning analysis, illustrating a non-random distribution across the region. pH was confirmed as the key environmental driver structuring Arctic soil bacterial communities, while total organic carbon, moisture and conductivity were shown to have little effect. Specialist taxa were more abundant in acidic and alkaline soils while generalist taxa were more abundant in acidoneutral soils. Of 48,147 bacterial taxa, a core microbiome composed of only 13 taxa that were ubiquitously distributed and present within 95% of samples was identified, illustrating the high potential for endemism in the region. Overall, our results demonstrate the importance of spatial and edaphic factors on the structure of Arctic soil bacterial communities.

microbiology↗

bioRxiv2019

To assemble or not to resemble -- A validated Comparative Metatranscriptomics Workflow (CoMW)

BackgroundMetatranscriptomics has been used widely for investigation and quantification of microbial communities activity in response to external stimuli. By assessing the genes expressed, metatranscriptomics provide an understanding of the interactions between different major functional guilds and the environment. Here, we present de-novo assembly-based Comparative Metatranscriptomics Workflow (CoMW) implemented in a modular, reproducible structure, significantly improving the annotation and quantification of metatranscriptomes. Metatranscriptomics typically utilize short sequence reads, which can either be directly aligned to external reference databases (\"assembly-free approach\") or first assembled into contigs before alignment (\"assembly-based approach\"). We also compare CoMW (assembly-based implementation) with assembly-free alternative workflow, using simulated and real-world metatranscriptomes from Arctic and Temperate terrestrial environments. We evaluate their accuracy in precision and recall using generic and specialized hierarchical protein databases.\n\nResultsCoMW provided significantly fewer false positives resulting in more precise identification and quantification of functional genes in metatranscriptomes. Using the comprehensive database M5nr, the assembly-based approach identified genes with only 0.6% false positives at thresholds ranging from inclusive to stringent compared to the assembly-free approach yielding up to 15% false positives. Using specialized databases (Carbohydrate Active-enzyme and Nitrogen Cycle), the assembly-based approach identified and quantified genes with 3-5x less false positives. We also evaluated the impact of both approaches on real-world datasets.\n\nConclusionsWe present an open source de-novo assembly-based Comparative Metatranscriptomics Workflow (CoMW). Our benchmarking findings support the argument of assembling short reads into contigs before alignment to a reference database, since this provides higher precision and minimizes false positives.

bioinformatics↗

bioRxiv2019

Total RNA-sequencing reveals multi-level microbial community changes and functional responses to wood ash application in agricultural and forest soil

Recycling of wood ash from energy production may counteract soil acidification and return essential nutrients to soils. However, wood ash amendment affects soil physicochemical parameters that control composition and functional expression of the soil microbial community. Here, we applied Total RNA-sequencing to simultaneously assess the impact of wood ash amendment on the active soil microbial communities and the expression of functional genes from all microbial taxa. Wood ash significantly affected the taxonomic (rRNA) as well as functional (mRNA) profiles of both agricultural and forest soil. Increase in pH, electrical conductivity, dissolved organic carbon and phosphate were the most important physicochemical drivers for the observed changes. Wood ash amendment increased the relative abundance of the copiotrophic groups Chitinonophagaceae (Bacteroidetes) and Rhizobiales (Alphaproteobacteria) and resulted in higher expression of genes involved in metabolism and cell growth. Finally, Total RNA-sequencing allowed us to show that some groups of bacterial feeding protozoa increased concomitantly to the enhanced bacterial growth, which shows their pivotal role in the regulation of bacterial abundance in soil.

microbiology↗

bioRxiv2019

Transcriptomic responses to warming and cooling of an Arctic tundra soil microbiome

BackgroundArctic surface soils experience pronounced seasonal changes in temperature and chemistry. However, it is unclear how these changes affect microbial degradation of organic matter, nitrogen cycling and microbial stress responses. We combined measurements of microbiome transcriptional activity, CO2 production, and pools of carbon and nitrogen to investigate the microbial response to warming in the laboratory, from -10 {degrees}C to 2 {degrees}C, and subsequent cooling, from 2 {degrees}C to -10 {degrees}C, of a high Arctic tundra soil from Svalbard, Norway.\n\nResultsGene expression was unaffected by warming from -10 {degrees}C to -2 {degrees}C and by cooling from -2 {degrees}C to -10 {degrees}C, while upon freezing (2 {degrees}C to -2 {degrees}C) a defense response against oxidative stress was observed. Following modest transcriptional changes one day after soil thaw, a more pronounced response was observed after 17 days, involving numerous functions dominated by an upregulation of genes involved in transcription, translation and chaperone activity. Transcripts related to carbohydrate metabolism and degradation of complex polymers (e.g. cellulose, hemicellulose and chitin) were also enhanced following 17 days of soil thaw, which was accompanied by a four-fold increase in CO2 production. In addition, anaerobic ammonium oxidation and turnover of organic nitrogen were upregulated. In contrast, nitrification, denitrification and assimilatory nitrate reduction were downregulated leading to an increase in the concentration of soil inorganic nitrogen.\n\nConclusionthe microorganisms showed negligible response to changes in sub-zero temperatures and a delayed response to thaw, which after 17 days led to upregulation of soil organic matter degradation and enhanced CO2 production, as well as downregulation of key pathways in nitrogen cycling and a concomitant accumulation of inorganic nitrogen available for plants.

microbiology↗