Peak Abundance Research Articles

The Entomo-Toxicological Effect Of Dichlorvos on Cuticular Hydrocarbon Profiles of Some Sarco-Saprophagous Insects for Forensic Applications.

Forensic entomology has relied on species-specificity, quantitative and qualitative variations of cuticular hydrocarbons to successfully carry out chemotaxonomic identification of insects based on species, age and gender. This work studied the effects of dichlorvos on the cuticular hydrocarbon profiles of some adult sarco-saprophagous insects of forensic importance that fed on dichlorvos-poisoned carrions for utility during death investigations. Cuticular hydrocarbons (CHCs) were extracted from adult insects of the species Chrysomya albiceps, Sarcophaga exuberans, Musca domestica, Hermetia illucens, Dermestes maculatus and Necrobia rufipes from both dichlorvos-poisoned and control pig (Sus scrofa Linnaeus) carrions and subjected to chemotaxonomic profiling using Gas Chromatography-Mass Spectrometry (GC-MS). A total of 41 CHCs were successfully identified from insects of both the dichlorvos-poisoned and control carrions ranging from C8 to C33 carbons consisting of majorly the n-alkanes, methyl branched alkanes and an alkene. There was a higher abundance of CHCs present in the insects of dichlorvos-poisoned carrions than the control group. The highest mean peak concentration and abundance of the CHCs was recorded by 2,6,10,14 -Tetramethyl Pentadecane (10.38 ± 0.53μg/mg for dichlorvos-poisoned carrions and 8.99 ± 1.13μg/mg for the control carrions). The visualization of the species-specific differences in CHCs compositions showed less overlapping CHCs clusters and quantitative metrics of principal component analysis plots of the insects from both carrion groups with high eigenvalues > 3 which were indications of good species level discrimination. The study showed that insects' CHCs profiles of dichlorvos-poisoned and control carrions exhibited uniqueness cum variations in terms of abundance and chemical identity.

Integrating single-cell RNA and T cell/B cell receptor sequencing with mass cytometry reveals dynamic trajectories of human peripheral immune cells from birth to old age

A comprehensive understanding of the evolution of the immune landscape in humans across the entire lifespan at single-cell transcriptional and protein levels, during development, maturation and senescence is currently lacking. We recruited a total of 220 healthy volunteers from the Shanghai Pudong Cohort (NCT05206643), spanning 13 age groups from 0 to over 90 years, and profiled their peripheral immune cells through single-cell RNA-sequencing coupled with single T cell and B cell receptor sequencing, high-throughput mass cytometry, bulk RNA-sequencing and flow cytometry validation experiments. We revealed that T cells were the most strongly affected by age and experienced the most intensive rewiring in cell–cell interactions during specific age. Different T cell subsets displayed different aging patterns in both transcriptomes and immune repertoires; examples included GNLY+CD8+ effector memory T cells, which exhibited the highest clonal expansion among all T cell subsets and displayed distinct functional signatures in children and the elderly; and CD8+ MAIT cells, which reached their peaks of relative abundance, clonal diversity and antibacterial capability in adolescents and then gradually tapered off. Interestingly, we identified and experimentally verified a previously unrecognized ‘cytotoxic’ B cell subset that was enriched in children. Finally, an immune age prediction model was developed based on lifecycle-wide single-cell data that can evaluate the immune status of healthy individuals and identify those with disturbed immune functions. Our work provides both valuable insights and resources for further understanding the aging of the immune system across the whole human lifespan.

Abundance survey of crustacean “y-larvae” (Thecostraca: Facetotecta) over a fringing reef in Okinawa, Japan, with special reference to the two dominant planktotrophic and lecithotrophic naupliar types

Facetotecta, or “y-larvae”, are mysterious planktonic crustaceans that are known only from their larval instars, but which are often assumed to be endoparasitic as adults. Dozens of mostly undescribed forms occur in the shallow-water plankton over a fringing reef at Sesoko Island, Okinawa, Japan. Recently, it has become possible to discriminate the different forms of their nauplius-stage larvae (“y-nauplii”) in a replicable way. A large year-to-year overlap in morphospecies recovered during fieldwork at Sesoko Island in 2018, 2019, and 2023 suggests that a full inventory is close at hand. To date, 49 morphospecies of y-nauplii (8 planktotrophic, 41 lecithotrophic) have been recognized in the area, among which three have been formally described. A detailed analysis of the temporal fluctuations in abundance during October 2023 showed that most morphospecies were rare, but two were particularly common: Type A*, a planktotroph with a long (> 3 weeks) period of naupliar development allowing for long-distance dispersal, and Type AG*, a lecithotroph with a short (3 days) period of development that implies rapid local recolonization. During the survey, both types showed distinct, largely non-overlapping peaks in abundance, related perhaps to their different dispersal/feeding strategies. An examination of the morphology of the swimming/feeding appendages in y-nauplii of Types A* and AG*, together with a mapping of feeding versus non-feeding nauplii on a recent comprehensive phylogeny of Facetotecta, suggests that broader taxonomic coverage of naupliar feeding structures in this group may provide useful information regarding the evolutionary direction of planktotrophy versus lecithotrophy in marine larvae.

Important ecophysiological roles of Nocardiopsis in lignocellulose degradation during aerobic compost with humic acid addition.

Improving lignocellulose degradation and organic matter conversion in agricultural and livestock wastes remains a great challenge. Here, the contribution of humic acid (HA) to lignocellulose degradation was investigated, focusing on the abundance of key microbial species and carbohydrate-active enzymes during aerobic composting. The results demonstrated that the addition of HA not only increased the complexity of the microbial network, but also enhanced the positive interaction between microorganism. The abundance of phylum Actinobacteria related to lignin degradation was significantly increased, especially genus Nocardiopsis (50.97 %), and Nocardiopsis was significantly positively correlated with HA and humus (HS) (p<0.05). Additionally, the abundance of GH (43.45%) and AA (5.88%) enzymes and the activation of metabolic pathways of AA, carbohydrates and energy were significantly increased (p<0.05). Remarkably, the quantity of lignocellulose-degrading genes and carbohydrate-active enzymes experienced a marked boost (p<0.05), with the peak abundance observed in Nocardiopsis. The structural equation model revealed that the addition of HA boosted the abundance of Nocardiopsis, which in turn amplified lignocellulose degradation by up-regulating lignocellulose degradation genes and enhancing carbohydrase activity, and facilitating the conversion of HA and FA. The lignocellulose degradation experiment verified that Nocardiopsis alba exhibited good ability in the degradation of cellulose and hemicellulose. These findings provided a novel perspective on the mechanisms underlying lignocellulose degradation, and broaden the understanding of the ecophysiological role of Nocardiopsis in composting system.

Dynamic Modelling Analysis of &lt;i&gt;Vibrio &lt;/i&gt;sp. and Plankton Abundance in Intensive Shrimp Pond

Vibrio sp. and plankton are important microorganisms in shrimp pond ecosystems. The research aims to predict the dynamics of Vibrio sp. and plankton abundance in intensive shrimp pond ecosystems based on causal model analysis. The research method used is an ex-pose facto causal design concept with quantitative descriptive data analysis using causal dynamic modeling. The results showed the water quality in the pond has a high correlation, except Vibrio sp. and alkalinity. In the pond ecosystem 24 genus of plankton from 6 classes. Chlorella sp. is the dominant plankton genus with an abundance of 1.00E+05-4.00E+05 cells/ml. Vibrio sp. abundance in ponds ranged from 1.38E+03 - 1.31E+05 CFU/ml. Based on the results of dynamic modelling, the growth pattern of Vibrio sp. lasted for 30 weeks which was divided into 4 growth phases. The conclusion of this study is that Vibrio sp. will dynamically experience a pure growth rate for 30 weeks with details of the initial growth phase (1-7 weeks), logarithmic growth phase (8-14 weeks), exponential phase (15-21 weeks), and growth declination phase (22-30 weeks). The growth phase of Vibrio sp. has a high degree of similarity to the growth pattern of plankton in the pond water ecosystem correlatively. The novelty of this research lies in the discovery of an estimation model for the abundance of Vibrio sp. and plankton during the shrimp farming cycle. This finding can serve as a fundamental reference for farmers to optimize feeding processes and conduct regular siphoning during the peak abundance of Vibrio sp. and plankton.

Climate-driven variation in the phenology of juvenile Ixodes pacificus on lizard hosts.

Ectothermic arthropods, like ticks, are sensitive indicators of environmental changes, and their seasonality plays a critical role in tick-borne disease dynamics in a warming world. Juvenile tick phenology, which influences pathogen transmission, may vary across climates, with longer tick seasons in cooler climates potentially amplifying transmission. However, assessing juvenile tick phenology is challenging in climates where desiccation pressures reduce the time ticks spend seeking blood meals. To improve our understanding of juvenile tick seasonality across a latitudinal gradient, we examine Ixodes pacificus phenology on lizards, the primary juvenile tick host in California, and explore how climate factors influence phenological patterns. Between 2013 and 2022, ticks were removed from 1,527 lizards at 45 locations during peak tick season (March-June). Tick counts were categorized by life stage (larvae and nymphs) and linked with remotely sensed climate data. Juvenile phenology metrics, including abundance, date of peak abundance, and temporal overlap between larval and nymphal populations, were analyzed along a latitudinal gradient, including tick abundances on lizards, Julian date of peak mean abundance. Generalized Additive Models (GAMs) were applied to assess climate-associated variation in juvenile abundance on lizards. Mean tick abundance per lizard ranged from 0.17 to 47.21 across locations, with the highest in the San Francisco Bay Area and lowest in Los Angeles, where more lizards had zero ticks attached. In the San Francisco Bay Area, peak nymphal abundance occurred 25 days earlier than peak larval abundance. Temporal overlap between larval and nymphal stages at a given location varied regionally, with northern areas showing higher overlap. We found that locations with higher temperatures and increased drought stress were linked to lower tick abundances, though the magnitude of these effects depended on regional location. Our study, which compiled 10 years of data, reveals significant regional variation in juvenile I. pacificus phenology across California, including differences in the abundance, peak timing, and temporal overlap. These findings highlight the influence of local climate on tick seasonality, with implications for tick-borne disease dynamics in a changing climate.

Seasonal Distribution and Diversity of Non-Insect Arthropods in Arid Ecosystems: A Case Study from the King Abdulaziz Royal Reserve, Kingdom Saudi Arabia.

The biodiversity of invertebrate animals is largely affected by climatic changes. This study evaluates the seasonal abundance and diversity of non-insect arthropods in the King Abdulaziz Royal Reserve (KARR), Saudi Arabia, over four collection periods (summer, autumn, winter, and spring) during 2023. Sampling was conducted across multiple sites in the reserve using both active (manual collection and active surveying for the diurnal species) and passive (pitfall traps and malaise traps for the nocturnal species) methods. A total of 586 non-insect arthropod specimens were collected, representing four classes: Arachnida, Chilopoda, Branchiopoda, and Malacostraca. The results show that the most abundant species was the jumping spider Plexippus paykulli, which dominated collections across two seasons, with a peak abundance of 50.7% in late summer. Seasonal variations in non-insect arthropod diversity were observed, with a lower diversity recorded during January-March (4 species, and this may be attributed to this period revealing the lowest temperature reading recorded during the study period) and higher diversity in August-September (end of summer) and October-November (mid of autumn), with 14 species. Scorpions, particularly species from the families Buthidae and Scorpionidae, were common during the summer months, while solifuges and centipedes showed sporadic occurrences across seasons. These findings align with the results for arthropod distribution in arid regions, with temperature and resource availability as key drivers of biodiversity in desert environments because of their direct effects on the biochemical processes of these creatures. This study contributes valuable baseline data on the non-insect arthropod fauna of the KARR. The insights gained from this study can aid in conservation efforts and provide a foundation for further research on non-insect arthropod ecology in arid landscapes.

Impact of late rainy season indoor residual spraying on holoendemic malaria transmission: a cohort study in northern Zambia.

Indoor residual spraying (IRS) is a malaria control strategy implemented before the rainy season. Nchelenge District, Zambia is a holoendemic setting where IRS has been conducted since 2008 with little impact on malaria incidence or parasite prevalence. Pre-rainy season IRS may not reduce the post-rainy season peak abundance of the major vector, Anopheles funestus. A controlled, pre-post, prospective cohort study assessed the impact of late-rainy season IRS on malaria prevalence, incidence, hazard, and vector abundance. Three hundred eighty-two individuals were enrolled across four household clusters, of which two were sprayed in April 2022 toward the end of the rainy season. Monthly household and individual surveys and indoor overnight vector collections were conducted through August 2022. Multivariate regression and time-to-event analyses estimated the impact of IRS on outcomes measured by rapid diagnostic tests, microscopy, and quantitative polymerase chain reaction. Seventy two percent of participants tested positive by rapid diagnostic test at least once and incidence by microscopy was 3.4 infections per person-year. Residing in a household in a sprayed area was associated with a 52% reduction in infection hazard (hazards ratio: 0.48, 95% confidence interval [0.29, 0.78]) but not with changes in incidence, prevalence, or vector abundance. The study-wide entomological inoculation rate was 34 infectious bites per person per year. Monthly tracking of incidence and prevalence did not demonstrate meaningful changes in holoendemic transmission intensity. However, hazard of infection, which provides greater power for detecting changes in transmission, demonstrated that late rainy season IRS reduced malaria risk.

Vole hunting: novel predatory and carnivorous behavior by California ground squirrels

Dietary flexibility allows animals to respond adaptively to food pulses in the environment. Here we document the novel emergence of widespread hunting of California voles and carnivorous feeding behavior by California ground squirrels. Over two months in the twelfth year of a long-term study on the squirrel population, we document 74 events of juvenile and adult ground squirrels of both sexes depredating, consuming, and/or competing over vole prey. Our video footage, photographic evidence, and direct observations of marked individual squirrels provide insights into the ecological circumstances favoring behavioral flexibility in foraging associated with a decadal peak in vole abundance. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo241126ob01a

Spatio-temporal distribution and biotechnological potential of culturable yeasts in the intertidal sediments and seawater of Aoshan Bay, China.

Marine yeasts play a crucial role in marine microbial ecology, facilitating the biogeochemical cycling of carbon and nitrogen in marine ecosystems, while also serving as important reservoirs of bioactive compounds with extensive applications in pharmaceuticals, agriculture, and various industries. Intertidal flats, characterized by their complex ecological dynamics, are postulated to harbor a wealth of yeast resources. This study employed a culture-dependent approach to assess the diversity, spatio-temporal distribution, and biotechnological potential of yeast communities residing within the intertidal sediments and seawater of Aoshan Bay. A total of 392 yeast strains were identified from 20 distinct genera, encompassing 43 recognized species and four candidate novel species. Notably, 17 of these species were identified as novel occurrences in marine environments, underscoring the rich yeast biodiversity of the Aoshan Bay ecosystem, with Candida emerging as the dominant genus in both sedimentary and aqueous habitats. Yeast community composition exhibited significant spatial and temporal variation, with peak diversity and abundance observed in autumn, the subtidal zone, and the surface soil layer. No clear pattern, however, emerged linking these shifts to specific changes in community composition, highlighting the complex interactions between microbial communities, environmental variables, and anthropogenic disturbance. Although several yeast species isolated here have been previously recognized for their biotechnological potential, their diverse and abundant extracellular enzyme profiles were characterized, further highlighting their crucial role in organic matter decomposition and nutrient cycling within the tidal ecosystem, as well as their potential applicability in the food, fine chemical, textile, and pharmaceutical industries.IMPORTANCEThis study presents groundbreaking insights into the yeast diversity of Aoshan Bay, offering invaluable information on their spatial and temporal distribution patterns, as well as their biotechnological potential in the tidal environment. The findings reveal that the eutrophic intertidal flat is a rich repository of yeasts with abundant extracellular enzymatic activity and an important role in nutrient cycling and decomposition processes. Also, these yeasts serve as crucial indicators of ecosystem health and function and are excellent candidates for biotechnological and industrial applications. Collectively, this study not only expands our knowledge of the diversity and distribution of intertidal yeasts but also highlights their promising potential for biotechnological applications.

A glimpse into the Late Cretaceous (Cenomanian) palynology of the Arlington Archosaur Site, Texas, USA

The Arlington Archosaur Site between Dallas and Fort Worth, Texas, USA, is known as a rich fossiliferous section. The age of these rocks is generally considered to be Middle Cenomanian, but conflicting evidence suggests they may be as young as the Late Cenomanian–Early Turonian. To address the issue, a palynological study was designed and conducted based on close sampling of the four lithofacies associations, labelled A to D, in ascending order. The study was quantitative and focused on palynological associations to determine the palaeoenvironment, palaeoclimate, biostratigraphy and age of the exposure. The rich palynological assemblages comprise spores from seedless plants, gymnosperms, angiosperms, fungi, freshwater algae, acritarchs and dinoflagellate cysts. Bryophyte spores were abundant mainly in Facies A and B, with Zlivisporis cenomanianus taking over the habitat of bryophytes in Facies D. Lycophytes abundant in the alluvial and coastal plains are considered to have been transported. Conifer pollen represent the predominant group of gymnosperms, mainly transported into the section. Freshwater algal remains include Schizophacus laevigatus/Ovoidites parvus, Schizosporis reticulatus, Botryococcus sp. and Pediastrum sp. The overall terrestrial vegetation represented in the palynological assemblages indicates tropical to subtropical palaeoclimatic conditions. In addition, the assemblage richness and abundance peaks of dinoflagellate cysts are interpreted as increased marine influence and possible flooding surfaces. The results support the alternation of marine incursions within deltaic and floodplain sequences related to short-term climate oscillations that affected the vegetation on the upland and lowland drainage areas. Key palynological markers point to an early Late Cenomanian age whereas the Cyclonephelium compactum–membraniphorum (Ccm morphological plexus) presence signals the incursion of boreal waters during the Plenus Cold Event of the Ocean Anoxic Event 2 reaching the southern coast of Appalachia.

Colonization of Blowflies (Diptera: Calliphoridae) and Association Time Between Adults and Immatures in Pig Carcass Decomposition: One Day to Change.

Blowflies are often the first to colonize a cadaver, making them valuable forensic indicators for estimating the post-mortem interval (PMI). However, understanding the decomposition process by blowflies in practice presents challenges due to the direct influence of adults and larvae on the process. Environmental factors can either hinder or stimulate colonization by different species, leading to variability across different settings. In this study, we aimed to investigate the variation in the community of adult and immature stages of Calliphoridae blowflies during pig carcass decomposition in an island area of the Amazon rainforest. We identified changes in abundance, richness, and species composition separately for adults and larvae and measured the congruence between larval and adult communities. Our findings revealed that the peak abundance of adults preceded the peak abundance of larvae during carcass decomposition. Eleven species were collected within the first 4days of decomposition, of which only seven colonized the carcass. Species composition differed between life stages and decomposition phases, with larvae associated with the skeletonization phase and adults with the colliquative phase. The species composition of adults collected from the decomposing carcass corresponded to that of larvae collected 1day later. This is the first study conducted in an Amazonian island environment in the extreme north of Brazil to document the cadaveric fauna and analyze the congruence between adult and larval communities of blowflies. These insights contribute to forensic entomology understanding and assist forensic professionals, particularly in tropical regions with high rates of unsolved homicides like Brazil.

Characteristics of typical habitats of the river lamprey Lampetra fluviatilis larvae (Petromyzontidae)

The paper describes typical habitats of the European river lamprey (Lampetra fluviatilis (L., 1758)) larvae in the rivers of the Leningrad Region. The density of ammocoetes, abiotic components of biotopes, as well as the structure of benthic and planktonic algae communities, zooplankton, and macrozoobenthos were estimated. It has been shown that the preferred soils for larvae are sands 0.25 mm. Oligochaeta and Chironomidae larvae reached high levels of quantitative development together with ammocoetes. Algae and zooplankton communities were not decisive for lamprey larvae and have expressed seasonal patterns with peaks of abundance in the spring. The part of lamprey larvae in the abundance of benthic coenoses can reach significant values – the part in the total biomass of macrozoobenthos was 30–80%.

Temperature niche and body size condition phenological responses of moths to urbanization in a subtropical city.

Urbanization in temperate climates often advances the beginning and peak of biological events due to multiple factors, especially urban heat islands. However, the effect of urbanization on insect phenology remains understudied in more tropical areas, where temperature may be a weaker phenological cue. We surveyed moths across an urban gradient in a subtropical city weekly for a year to test how impervious surface and canopy cover impact phenology at the caterpillar and adult life stages. For macro-moths, we also examine how these effects vary with life history traits. When pooling all individuals, we found no effect of urbanization proxy variables on timing of caterpillar or adult phenology. At the species-specific level, we found timing of peak adult macro-moths is influenced by canopy cover, which also interacts with two traits: temperature niche and body size. Cold-adapted species delay timing of peak abundance in more shaded sites, while warm-adapted species were not affected. Smaller species, associated with lower dispersal ability, were more phenologically sensitive to canopy cover than larger bodied species. These results highlight the importance of canopy cover within cities and its interaction with species' traits in mediating impact of urbanization on moth phenology in subtropical systems.

Individual Choices of Wintering Areas Drive Adult Survival Heterogeneity in a Long-Lived Seabird.

Seasonal migration has evolved as an adaptation for exploiting peaks of resource abundance and avoiding unfavourable climatic conditions. Differential migratory strategies and choices of wintering areas by long-distance migratory species may impose varying selective pressures and mortality risks with fitness consequences. Recently developed tracking technologies allow wintering movements of migratory species to be studied. However, these technologies typically involve a limited number of tracked individuals, which gives low statistical power for any robust estimate of survival probabilities. Additionally, when utilising geolocators, data become accessible only upon individual recapture, presenting a potential source of bias. We used multievent modelling to include information of 147 identified wintering tracks in the analysis of 1104 long-term individual capture histories (2000-2022) of migratory seabird Calonectris diomedea and then test if individual preferences for wintering areas may drive heterogeneity in adult survival. We also examined individual fidelity to wintering areas and tested if climatic and oceanographic conditions, as represented by the wNAO and SOI climatic indices, influenced survival and fidelity. The probability of fidelity to a wintering area was ca. 0.79. Annual changes between areas were influenced by environmental variability driven by the wNAO. Survival probability was influenced by the SOI and differed between wintering areas; these differences coupled with high wintering site fidelity, generated individual heterogeneity in adult survival. Our study reveals that, over the last two decades, some individuals wintered in less suitable areas, with nonnegligible consequences on adult survival, the parameter to which the population growth rate is most sensitive in long-lived species. Winter oceanographic conditions such as stormy weather or the proximity to upwellings probably play a relevant role in driving survival heterogeneity. Further research is needed to enhance our understanding of how the interlinked effects of climate, local selective pressures and individual condition shape population dynamics in migratory species.

Long-term data reveal widespread phenological change across major US estuarine food webs.

Climate change is shifting the timing of organismal life-history events. Although consequential food-web mismatches can emerge if predators and prey shift at different rates, research on phenological shifts has traditionally focused on single trophic levels. Here, we analysed >2000 long-term, monthly time series of phytoplankton, zooplankton, and fish abundance or biomass for the San Francisco, Chesapeake, and Massachusetts bays. Phenological shifts occurred in over a quarter (28%) of the combined series across all three estuaries. However, phenological trends for many taxa (ca. 29-68%) did not track the changing environment. While planktonic taxa largely advanced their phenologies, fishes displayed broad patterns of both advanced and delayed timing of peak abundance. Overall, these divergent patterns illustrate the potential for climate-driven trophic mismatches. Our results suggest that even if signatures of global climate change differ locally, widespread phenological change has the potential to disrupt estuarine food webs.

1997–2016, Twenty Years of Pollen Monitoring Activity in Rome Tor Vergata (Rome South-East): Trends Analysis

Global environmental change is rapidly altering the dynamics of terrestrial vegetation, with consequences for the functioning of the Earth system. Recent studies show that climate change is influencing the phenology and distribution of plants. Airborne pollen reflects the flowering period of the plant, which is influenced by meteorological variables such as temperature and rainfall. The analysis of pollen trends is a very useful tool for understanding the effects of climate change on vegetation. In fact, it is accepted that the onset and peak abundance of certain pollen types should be used as possible bioindicators of climate change. The aim of the work is to analyze the presence of various pollen in Rome—from their release from the anthers to their permanence in the atmosphere, the trends of phenological (start, length, and end of the pollen season) and production (pollen abundance and pollen peaks) pollen indicators, the trends of the meteorological variables mainly involved (temperature and precipitation), and any relationships between pollen and meteorological variables, also based on the variation in vegetation. In the period considered, the analysis of the pollen spectra shows an increasing trend in herbaceous taxa, probably attributed to a gradual abandonment of farming practices in the neighboring area, which in recent years has been the subject of intense new construction activity and to a progressive deterioration in the maintenance of green areas.

Diversity and prevalence of Leucocytozoon in black flies (Diptera: Simuliidae) of Thailand.

Leucocytozoonosis, a parasitic disease of birds, is caused by haemosporidian protozoan parasites of the genus Leucocytozoon, which infect diverse avian species, including poultry. These parasites are transmitted by several black fly species, but knowledge of the factors determining the diversity and prevalence in these vectors, which is crucial for fully understanding disease epidemiology, is largely unexplored. In this study, we investigated factors associated with the prevalence and diversity of Leucocytozoon species in black flies from Thailand. Adults of two black fly taxa (Simulium asakoae Takaoka and Davies complex and S. khelangense Takaoka, Srisuka and Saeung) were collected using sweep nets at nine locations in northern and northeastern regions of Thailand. Specimens were identified morphologically and the results corroborated by DNA barcoding. Molecular methods using specific primers for amplification of the mitochondrial cytochrome b (cyt b) gene of Leucocytozoon were used to detect the parasite in black flies. Species and lineages of Leucocytozoon were determined using the MalAvi database of malaria parasites and related haemosporidians in avian hosts. Regression analysis was used to examine relationships between Leucocytozoon diversity and prevalence, black fly abundance and habitat characteristics. A total of 11,718 adult black flies were collected, of which 4367 were members of the S. asakoae complex and 7351 were S. khelangense. For molecular detection of Leucocytozoon, we randomly selected 300 individual female black flies of the S. asakoae complex and 850 females of S. khelangense pooled into groups of five individuals (= 170 pools). A total of 34 of the 300 specimens of the S. asakoae complex and 118 of the 170 pools of S. khelangense were positive for Leucocytozoon. Fifty-four lineages (haplotypes) were identified, all of which belonged to those reported in domestic chickens, Gallus gallus, with one exception that was identified in S. khelangense and found to be closely related to the Leucocytozoon lineages reported in owls; this is the first record of the latter lineage in Asian black flies. Among these haplotypes, nine and 45 were exclusively found in the S. asakoae complex and S. khelangense, respectively. No lineage was shared between these black fly taxa. Analysis of similarity (ANOSIM) revealed significant Leucocytozoon lineage composition between the two black flies. Phylogenetic analysis found that Leucocytozoon lineages in the S. asakoae complex and S. khelangense are largely isolated, agreeing with the ANOSIM result. The overall prevalence of Leucocytozoon in the S. asakoae complex was 11.3% and ranged from 9% to 13% in each collection. Leucocytozoon prevalence in S. khelangense was 21%, varying from 13% to 37% in each collection. The Shannon H' index indicated greater Leucocytozoon diversity in S. khelangense (H' = 3.044) than in the S. asakoae complex (H' = 1.920). Regression analysis revealed that Leucocytozoon diversity was positively related to black fly abundance and negatively related to maximum air temperature. The results of this study show that the prevalence and diversity of Leucocytozoon lineages in the S. asakoae complex and S. khelangense from Thailand were associated with the abundance of these black flies and with air temperature. The Leucocytozoon lineages identified also showed some degree of black fly taxon specificity, possibly related to different abundance peaks of these vectors. The environmental conditions that favor the development of black flies are possibly a driver of Leucocytozoon prevalence, diversity and vector-parasite co-evolution.

Revision of Sagenopteris (Caytoniales): a major lineage of the Mesozoic seed plants

AbstractSagenopteris is the most common fossil organ attributed to Caytoniales and is represented by compound leaves having several (usually four) lanceolate leaflets in pseudo‐palmate arrangement. Since Presl's description of Sagenopteris in 1838, at least 82 species have been identified worldwide. However, most were established on a few isolated leaflets without sufficient details for confident segregation from other forms. After a global evaluation of the character states, nomenclature and taxonomic validity of all described Sagenopteris species, only five can be retained as nomenclaturally valid and morphologically distinct: Sagenopteris acuminata (lectotype species), S. colpodes, S. hallei, S. phillipsii and S. pualensis. Comprehensive assessment of Sagenopteris foliage based on historical studies and institutional collections shows a high degree of morphological plasticity within individual leaf populations. Multivariate plots of key leaf characters show broad morphotypes within populations that, if selectively sampled, might readily result in the recognition of multiple fossil‐species. Cuticular features are more stable for species‐level differentiation. Temporo‐spatial analysis of Sagenopteris suggests it originated in the European (palaeo‐subtropical) region by the Anisian (Middle Triassic) and underwent significant range expansion during the Late Triassic. Surviving the end‐Triassic mass extinction, Sagenopteris quickly became one of the dominant gymnosperms in the aftermath of the biotic crisis, reaching its peak abundance during the Early and Middle Jurassic. This taxon began to decline in floristic importance from the Late Jurassic to Late Cretaceous. The youngest occurrences of Sagenopteris, globally, are from Cenomanian–Campanian assemblages of middle to high northern latitudes. No examples are known from the Cenozoic.

The glomerular circadian clock temporally regulates basement membrane dynamics and the podocyte glucocorticoid response

Kidney physiology shows diurnal variation, and a disrupted circadian rhythm is associated with kidney disease. However, it remains largely unknown whether glomeruli, the filtering units in the kidney, are under circadian control. Here, we investigated core circadian clock components in glomeruli, together with their rhythmic targets and modes of regulation. With clock gene reporter mice, cell-autonomous glomerular clocks which likely govern rhythmic fluctuations in glomerular physiology were identified. Using circadian time-series transcriptomic profiling, the first circadian glomerular transcriptome with 375 rhythmic transcripts, enriched for extracellular matrix and glucocorticoid receptor signaling ontologies, were identified. Subsets of rhythmic matrix-related genes required for basement membrane assembly and turnover, and circadian variation in matrix ultrastructure, coinciding with peak abundance of rhythmic basement membrane proteins, were uncovered. This provided multiomic evidence for interactions between glomerular matrix and intracellular time-keeping mechanisms. Furthermore, glucocorticoids, which are frequently used to treat glomerular disease, reset the podocyte clock and induce rhythmic expression of potential glomerular disease genes associated with nephrotic syndrome that included NPHS1 (nephrin) and NPHS2 (podocin). Disruption of the clock with pharmacological inhibition altered the expression of these disease genes, indicating an interplay between clock gene expression and key genes required for podocyte health. Thus, our results provide a strong basis for future investigations of the functional implications and therapeutic potential of chronotherapy in glomerular health and disease.