bluuebunny/crossref_metadata_2025 huggingface dataset:
Sulfoxaflor Alters Bemisia tabaci MED (Hemiptera: Aleyrodidae) Preference, Feeding, and TYLCV Transmission
Authors: Liu Baiming , Preisser Evan L , Yang Zezhong , Jiao Xiaoguo , Zhang Youjun
Published: May 2021

Many damaging agricultural pests can, in addition to their direct feeding damage, acquire and transmit plant pathogens. Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) is considered a ‘supervector’ of disease-causing plant pathogens and viruses. One of the most damaging of these is Tomato yellow leaf curl virus (TYLCV), a circulatively transmitted begomovirus than can extensively damage field and greenhouse crops. Because sustained feeding periods are necessary to acquire and transmit circulatively transmitted viruses, pesticides that, in addition to their direct lethality, suppress feeding in surviving individuals may be particularly effective in decreasing viral transmission. We assessed the impact of sulfoxaflor, a sulfoximine insecticide, on the settling preference, feeding, and viral transmission of TYLCV-carrying B. tabaci on tomato. We found that viruliferous B. tabaci avoided both settling and feeding on sulfoxaflor-treated plants, and that sulfoxaflor virtually eliminated the transmission of TYLCV by B. tabaci. The antifeedant properties of sulfoxaflor have previously been reported in other pest systems; our results document similar effects on viruliferous B. tabaci and demonstrate that this pesticide can reduce TYLCV transmission by surviving individuals.
Associations Between Salivary Bacteriome Diversity and Salivary Human Herpesvirus Detection in Early Childhood: A Prospective Cohort Study
Authors: Blostein Freida , Foote Sydney , Salzman Elizabeth , McNeil Daniel W , Marazita Mary L , Martin Emily T , Foxman Betsy
Published: May 2021

Background

The bacteriome is associated with susceptibility to some eukaryotic viruses, but no study has examined associations between the salivary bacteriome and human herpesviruses (HHVs). We provide new prevalence and incidence estimates for salivary herpesviruses detection and estimate associations with bacteriome diversity in young children.

Methods

Salivary samples collected at ages ~2, 8, 12, and 24 months from 153 children participating in the Center for Oral Health Research in Appalachia cohort 2 (COHRA2) were screened for HHVs using the Fast-Track Neuro9 multiplex PCR assay, and for the bacteriome using 16S rRNA amplicon sequencing. We used Cox proportional hazard models to test for associations between the salivary bacteriome and hazards of cytomegalovirus (CMV) and human herpesvirus-6 (HHV6).

Results

CMV, HHV6, and Epstein-Barr virus (EBV) were detected at all visits. Human herpesvirus-7 (HHV7) was first detected at the 8-month visit and herpes simplex virus 1 (HSV1) was only detected at the 12-month visit. Varicella-zoster virus, herpes simplex virus 2, and human herpesvirus-8 were never detected. HHV6 (24-month cumulative incidence: 73.8%) and CMV (24-month cumulative incidence: 32.3%) were detected most frequently. Increasing salivary bacteriome diversity was associated with longer survival to first detection of CMV (hazard ratio [95% CI]: 0.24 [0.12, 0.49]) and HHV6 (hazard ratio [95% CI]: 0.24 [0.13, 0.44]).

Conclusion

CMV, HHV6, EBV, HHV7, and HSV1 were detected in the saliva during the first 2 years of life. Time to first detection of CMV and HHV6 was associated with salivary bacteriome diversity, suggesting a possible interaction between HHVs and the salivary bacteriome.
First reported congenital lumbar hernia with lumbo-costo-vertebral syndrome in the Middle-East: a case report
Authors: Danial Aghyad Kudra , Morjan Mohamad , Assi Ahmadfateh , Raslan Hasan , Bedon Mario , Khalil Hayat , Kalaji Nour
Published: May 2021

Congenital lumbar hernia is a rare disease affecting mainly infants. Its association with lumbo-costo-vertebral syndrome (LCVS) is hardly seen in the literature. We present a case of LCVS in a 1-month-old female infant presenting with a soft bulge in left lumbar region. Abdominal X-ray revealed absence of multiple ribs with a mild lumbar scoliosis and defective ninth vertebra. Ultrasonography showed absence lateral abdominal wall muscles in left lumbar region and 2.5 cm diameter lumbar hernia. Primary repair of the adnominal wall defect was performed without meshplasty and no recurrence was reported. We hope to enhance the literature of this rare disease with our case.
A novel class of inhibitors that target SRSF10 and promote p53-mediated cytotoxicity on human colorectal cancer cells
Authors: Sohail Muhammad , Shkreta Lulzim , Toutant Johanne , Rabea Safwat , Babeu Jean-Philippe , Huard Caroline , Coulombe-Huntington Jasmin , Delannoy Aurélie , Placet Morgane , Geha Sameh , Gendron Fernand-Pierre , Boudreau François , Tyers Mike , Grierson David S , Chabot Benoit
Published: May 2021

The elevated expression of the splicing regulator SRSF10 in metastatic colorectal cancer (CRC) stimulates the production of the pro-tumorigenic BCLAF1-L splice variant. We discovered a group of small molecules with an aminothiazole carboxamide core (GPS167, GPS192 and others) that decrease production of BCLAF1-L. While additional alternative splicing events regulated by SRSF10 are affected by GPS167/192 in HCT116 cells (e.g. in MDM4, WTAP, SLK1 and CLK1), other events are shifted in a SRSF10-independent manner (e.g. in MDM2, NAB2 and TRA2A). GPS167/192 increased the interaction of SRSF10 with the CLK1 and CLK4 kinases, leading us to show that GPS167/192 can inhibit CLK kinases preferentially impacting the activity of SRSF10. Notably, GPS167 impairs the growth of CRC cell lines and organoids, inhibits anchorage-independent colony formation, cell migration, and promotes cytoxicity in a manner that requires SRSF10 and p53. In contrast, GPS167 only minimally affects normal colonocytes and normal colorectal organoids. Thus, GPS167 reprograms the tumorigenic activity of SRSF10 in CRC cells to elicit p53-dependent apoptosis.
Polee: RNA-Seq analysis using approximate likelihood
Authors: Jones Daniel C , Ruzzo Walter L
Published: May 2021

The analysis of mRNA transcript abundance with RNA-Seq is a central tool in molecular biology research, but often analyses fail to account for the uncertainty in these estimates, which can be significant, especially when trying to disentangle isoforms or duplicated genes. Preserving uncertainty necessitates a full probabilistic model of the all the sequencing reads, which quickly becomes intractable, as experiments can consist of billions of reads. To overcome these limitations, we propose a new method of approximating the likelihood function of a sparse mixture model, using a technique we call the Pólya tree transformation. We demonstrate that substituting this approximation for the real thing achieves most of the benefits with a fraction of the computational costs, leading to more accurate detection of differential transcript expression and transcript coexpression.
Carbon ion radiotherapy eradicates medulloblastomas with chromothripsis in an orthotopic Li-Fraumeni patient-derived mouse model
Authors: Simovic Milena , Bolkestein Michiel , Moustafa Mahmoud , Wong John K L , Körber Verena , Benedetto Sarah , Khalid Umar , Schreiber Hannah Sophia , Jugold Manfred , Korshunov Andrey , Hübschmann Daniel , Mack Norman , Brons Stephan , Wei Pei-Chi , Breckwoldt Michael O , Heiland Sabine , Bendszus Martin , Debus Jürgen , Höfer Thomas , Zapatka Marc , Kool Marcel , Pfister Stefan M , Abdollahi Amir , Ernst Aurélie
Published: May 2021

Background

Medulloblastomas with chromothripsis developing in children with Li-Fraumeni Syndrome (germline TP53 mutations) are highly aggressive brain tumors with dismal prognosis. Conventional photon radiotherapy and DNA-damaging chemotherapy are not successful for these patients and raise the risk of secondary malignancies. We hypothesized that the pronounced homologous recombination deficiency in these tumors might offer vulnerabilities that can be therapeutically utilized in combination with high linear energy transfer carbon ion radiotherapy.

Methods

We tested high-precision particle therapy with carbon ions and protons as well as topotecan with or without PARP inhibitor in orthotopic primary and matched relapsed patient-derived xenograft models. Tumor and normal tissue underwent longitudinal morphological MRI, cellular (markers of neurogenesis and DNA damage-repair), and molecular characterization (whole-genome sequencing).

Results

In the primary medulloblastoma model, carbon ions led to complete response in 79% of animals irrespective of PARP inhibitor within a follow-up period of 300 days postirradiation, as detected by MRI and histology. No sign of neurologic symptoms, impairment of neurogenesis or in-field carcinogenesis was detected in repair-deficient host mice. PARP inhibitors further enhanced the effect of proton irradiation. In the postradiotherapy relapsed tumor model, median survival was significantly increased after carbon ions (96 days) versus control (43 days, P < .0001). No major change in the clonal composition was detected in the relapsed model.

Conclusion

The high efficacy and favorable toxicity profile of carbon ions warrants further investigation in primary medulloblastomas with chromothripsis. Postradiotherapy relapsed medulloblastomas exhibit relative resistance compared to treatment-naïve tumors, calling for exploration of multimodal strategies.
Cecum perforation due to a fish bone
Authors: Dung Le Thanh , Duc Nguyen Minh , My Thieu-Thi Tra , Linh Le Tuan , Luu Vu Dang , Thong Pham Minh
Published: May 2021

Foreign body (FB) ingestion is a common condition encountered in clinical practice, especially among the pediatric age group; however, this occurrence is rare among adults. Some FBs can induce the perforation of the gastrointestinal tract, including fish bones, chicken bones and toothpicks. The ingestion of FBs is rarely associated with bowel perforation, and most FBs are passed spontaneously. The ingestion of sharp and pointed objects typically produces adverse events related to the upper gastrointestinal system, and FBs are rarely retained in the colon. Bowel perforation caused by the ingestion of FBs should be diagnosed and treated in a timely manner. Here, we present the unusual case of a 51-year-old male who presented to the emergency room with complaints of acute abdominal pain secondary to fish bone ingestion, which triggered cecum perforation.
Examining climate change and sustainable/fast fashion in the 21st century: ‘Trash the Runway’
Authors: Boykoff Maxwell , Chandler Patrick , Church Presley , Osnes Beth
Published: May 2021

We interrogate fast fashion in the 21st century in the context of a changing climate, assessing emergent trends in sustainable fashion as an alternative consumption pathway through the annual ‘Trash the Runway’ event in Boulder, Colorado. In this research, we interviewed and surveyed designers and analyzed workshop activities that led up to their annual fashion show. We also interviewed and surveyed students at the University of Colorado who worked with designers to produce short films about them and their work. The project centers on decolonial practice by providing —who are often marginalized in decision-making processes—a stage to articulate policy and behavior changes to address climate change and sustainability. We found designers expressed reticence before the workshops and events to speak about climate change in everyday life, yet their design work creatively spoke powerfully for them, and they expressed less discomfort after the experience, while they advanced their skillset as climate communicators. Moreover, we found both designers and student partners reported that they think climate change will impact people greatly in the future. Also, while comparatively fewer respondents reported that climate change impacts them personally, our findings showed those noting personal impacts nearly doubled after participation in the sustainable fashion project. Although engagement with sustainable fashion helps to defetishize production processes and link consumption habits with awareness of climate and environmental change, more creative work should be done through fast- and sustainable-fashion endeavors to draw out spatial and temporal considerations of climate change threats here and now.
The role of negative emissions in meeting China’s 2060 carbon neutrality goal
Authors: Fuhrman Jay , Clarens Andres F , McJeon Haewon , Patel Pralit , Ou Yang , Doney Scott C , Shobe William M , Pradhan Shreekar
Published: May 2021

China’s pledge to reach carbon neutrality before 2060 is an ambitious goal and could provide the world with much-needed leadership on how to limit warming to +1.5°C warming above preindustrial levels by the end of the century. But the pathways that would achieve net zero by 2060 are still unclear, including the role of negative emissions technologies. We use the Global Change Analysis Model to simulate how negative emissions technologies, in general, and direct air capture (DAC) in particular, could contribute to China’s meeting this target. Our results show that negative emissions could play a large role, offsetting on the order of 3 GtCO2 per year from difficult-to-mitigate sectors, such as freight transportation and heavy industry. This includes up to a 1.6 GtCO2 per year contribution from DAC, constituting up to 60% of total projected negative emissions in China. But DAC, like bioenergy with carbon capture and storage and afforestation, has not yet been demonstrated anywhere approaching the scales required to meaningfully contribute to climate mitigation. Deploying NETs at these scales will have widespread impacts on financial systems and natural resources, such as water, land and energy in China.
Gene co-expression network analysis identifies BEH3 as a stabilizer of secondary vascular development in Arabidopsis
Authors: Furuya Tomoyuki , Saito Masato , Uchimura Haruka , Satake Akiko , Nosaki Shohei , Miyakawa Takuya , Shimadzu Shunji , Yamori Wataru , Tanokura Masaru , Fukuda Hiroo , Kondo Yuki
Published: May 2021

In plants, vascular stem cells located in the cambium continuously undergo self-renewal and differentiation during secondary growth. Recent advancements in cell sorting techniques have enabled access to the transcriptional regulatory framework of cambial cells. However, mechanisms underlying the robust control of vascular stem cells remain unclear. Here, we identified a new cambium-related regulatory module through co-expression network analysis using multiple transcriptome datasets obtained from an ectopic vascular cell transdifferentiation system using Arabidopsis cotyledons, Vascular cell Induction culture System Using Arabidopsis Leaves (VISUAL). The cambium gene list included a gene encoding the transcription factor BES1/BZR1 Homolog 3 (BEH3), whose homolog BES1 negatively affects vascular stem cell maintenance. Interestingly, null beh3 mutant alleles showed a large variation in their vascular size, indicating that BEH3 functions as a stabilizer of vascular stem cells. Genetic analysis revealed that BEH3 and BES1 perform opposite functions in the regulation of vascular stem cells and the differentiation of vascular cells in the context of the VISUAL system. At the biochemical level, BEH3 showed weak transcriptional repressor activity and functioned antagonistically to other BES/BZR members by competing for binding to the brassinosteroid response element. Furthermore, mathematical modeling suggested that the competitive relationship between BES/BZR homologs leads to the robust regulation of vascular stem cells.
Phosphorylation of WRKY16 by MPK3-1 is essential for its transcriptional activity during fiber initiation and elongation in cotton (Gossypium hirsutum)
Authors: Wang Na-Na , Li Yang , Chen Yi-Hao , Lu Rui , Zhou Li , Wang Yao , Zheng Yong , Li Xue-Bao
Published: May 2021

Cotton, one of the most important crops in the world, produces natural fiber materials for the textile industry. WRKY transcription factors play important roles in plant development and stress responses. However, little is known about whether and how WRKY transcription factors regulate fiber development of cotton so far. In this study, we show that a fiber-preferential WRKY transcription factor, GhWRKY16, positively regulates fiber initiation and elongation. GhWRKY16-silenced transgenic cotton displayed a remarkably reduced number of fiber protrusions on the ovule and shorter fibers compared to the wild-type. During early fiber development, GhWRKY16 directly binds to the promoters of GhHOX3, GhMYB109, GhCesA6D-D11, and GhMYB25 to induce their expression, thereby promoting fiber initiation and elongation. Moreover, GhWRKY16 is phosphorylated by the mitogen-activated protein kinase GhMPK3-1 at residues T-130 and S-260. Phosphorylated GhWRKY16 directly activates the transcription of GhMYB25, GhHOX3, GhMYB109, and GhCesA6D-D11 for early fiber development. Thus, our data demonstrate that GhWRKY16 plays a crucial role in fiber initiation and elongation, and that GhWRKY16 phosphorylation by GhMPK3-1 is essential for the transcriptional activation on downstream genes during the fiber development of cotton.
How Much Does Size Erode Mutual Fund Performance? A Regression Discontinuity Approach
Authors: Reuter Jonathan , Zitzewitz Eric
Published: May 2021

The level of diseconomies of scale in asset management has important implications for tests of manager skill and the expected level of performance persistence. To identify the causal impact of fund size on future returns, we exploit the fact that small differences in returns can cause discrete changes in Morningstar ratings that, in turn, generate discrete differences in fund size. Using our regression discontinuity approach, we find that ratings significantly increase fund size, but that fund size has a negligible effect on fund returns. Within Berk and Green’s (2004) model, the absence of meaningful fund-level diseconomies of scale implies that the lack of performance persistence arises from a lack of fund manager skill. Alternatively, the lack of performance persistence may arise from competitive pressures outside of their model.
Changes of evening exposure to electronic devices during the COVID-19 lockdown affect the time course of sleep disturbances
Authors: Salfi Federico , Amicucci Giulia , Corigliano Domenico , D’Atri Aurora , Viselli Lorenzo , Tempesta Daniela , Ferrara Michele
Published: May 2021

Study Objectives

During the coronavirus disease 2019 (COVID-19) lockdown, there was a worldwide increase in electronic devices’ daily usage. Prolonged exposure to backlit screens before sleep influences the circadian system leading to negative consequences on sleep health. We investigated the relationship between changes in evening screen exposure and the time course of sleep disturbances during the home confinement period due to COVID-19.

Methods

2,123 Italians (mean age ± standard deviation, 33.1 ± 11.6) were tested longitudinally during the third and the seventh week of lockdown. The web-based survey evaluated sleep quality and insomnia symptoms through the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. The second assessment survey inquired about intervening changes in backlit screen exposure in the two hours before falling asleep.

Results

Participants who increased electronic device usage showed decreased sleep quality, exacerbated insomnia symptoms, reduced sleep duration, prolonged sleep onset latency, and delayed bedtime and rising time. In this subgroup, the prevalence of poor sleepers and individuals reporting moderate/severe insomnia symptoms increased. Conversely, respondents reporting decreased screen exposure exhibited improved sleep quality and insomnia symptoms. In this subgroup, the prevalence of poor sleepers and moderate/severe insomniacs decreased. Respondents preserving screen time habits did not show variations of the sleep parameters.

Conclusions

Our investigation demonstrated a strong relationship between modifications of evening electronic device usage and time course of sleep disturbances during the lockdown period. Monitoring the potential impact of excessive evening exposure to backlit screens on sleep health is recommendable during the current period of restraining measures due to COVID-19.
A systematic review of psychosocial interventions for Latinx and American Indian patient-family caregiver dyads coping with chronic health conditions
Authors: McCarthy Michael J , Sanchez Angelica , Garcia Y Evie , Bakas Tamilyn
Published: May 2021

Latinx and American Indians experience high rates of chronic health conditions. Family members play a significant role as informal caregivers for loved ones with chronic conditions and both patients and family caregivers report poor psychosocial outcomes. This systematic review synthesizes published studies about psychosocial interventions for Latinx and American Indian care dyads to determine: (i) the benefits of these interventions; (ii) their distinguishing features or adaptations, and; (iii) recommendations for future intervention development. Out of 366 records identified, seven studies met inclusion criteria. Interventions demonstrated benefits to outcomes such as disease knowledge, caregiver self-efficacy and burden, patient and caregiver well-being, symptom distress, anxiety and depression, and dyadic communication. Distinguishing features included tailoring to cultural values, beliefs, and delivery preferences, participants’ level of acculturation, and population-specific issues such as migratory stressors and support networks. Based upon this review, six recommendations for future intervention development are put forth.
COVID-19 exposure and diagnosis among college student drinkers: links to alcohol use behavior, motives, and context
Authors: Allen Hannah K , Cohen-Winans Samantha , Armstrong Kaitlyn , Clark Nash C , Ford M Allison
Published: May 2021

The COVID-19 pandemic is a public health crisis. College student alcohol use is highly prevalent and primarily occurs in social settings where risk for COVID-19 transmission is heightened. This study explored the associations between alcohol use frequency, quantity, motives, and context with: (i) quarantine due to COVID-19 exposure and (ii) a positive diagnosis for COVID-19. A sample of n = 409 college student drinkers completed an online survey about their health and behaviors during the Fall 2020 semester. Since the start of the semester, 36% of students quarantined and 13% of students received a COVID-19 diagnosis. More frequent alcohol use was associated with increased odds of both quarantine and COVID-19 diagnosis. More frequent drinking for social motives was associated with increased likelihood of quarantine, and more frequent drinking for conformity motives was associated with increased likelihood of COVID-19 diagnosis. Participants who often drank alone or with a small group of friends were about half as likely to have quarantined, while those who often drank with a large group of friends were almost twice as likely to have quarantined. Participants who often drank in a bar or nightclub had almost three times the odds of a COVID-19 diagnosis. Frequent alcohol use and drinking for social and conformity motives and in certain contexts are linked to increased likelihood of COVID-19 exposure and diagnosis. Alcohol use prevention efforts, coupled with messaging to discourage large social gatherings in public places, might help to mitigate the spread of COVID-19 among college students.
Novel next-generation sequencing-based methodologies to characterize the mutational consequences of (prenatal) chemotherapy exposure in noncancerous tissue
Authors: Struys Ilana , Lenaerts Liesbeth , Thienpont Bernard , Amant Frédéric
Published: May 2021

Purpose of review

Although chemotherapeutics are considered as genotoxins for decades, their exact mutagenic impact on the genome of cancerous and normal cells of cancer patients was unknown for a long time. However, this knowledge is necessary to understand the long-term side effects of chemotherapy. A particular condition represents pregnant cancer patients being treated with chemotherapy. Since certain chemotherapeutics can cross the placenta, concerns exist about possible mutational effects on the fetus’ genome with potential long-term health consequences.

Recent findings

Recent advances of next-generation sequencing (NGS) techniques have opened possibilities to explore the exact mutational footprint of chemotherapies in healthy tissue from treated cancer patients. However, the ultra-low frequency of chemotherapy-induced mutations, introduction of technical artefacts, and inaccessibility of normal tissue has posed important limitations. This review discusses five state-of-the-art approaches that were recently designed to overcome these drawbacks.

Results of the latest investigations give valuable insights into the genome-wide genotoxicity profile of frequently applied chemotherapies, with most of these drugs being associated with a signature of random base substitutions and small indels. Though these findings still might be limited to extrapolate to healthy tissue, they pave the way for studies on the origin of long-term chemotherapy-related adverse health effects.
The inherent flexibility of type I non-ribosomal peptide synthetase multienzymes drives their catalytic activities
Authors: Bonhomme Sarah , Dessen Andréa , Macheboeuf Pauline
Published: May 2021

Non-ribosomal peptide synthetases (NRPSs) are multienzymes that produce complex natural metabolites with many applications in medicine and agriculture. They are composed of numerous catalytic domains that elongate and chemically modify amino acid substrates or derivatives and of non-catalytic carrier protein domains that can tether and shuttle the growing products to the different catalytic domains. The intrinsic flexibility of NRPSs permits conformational rearrangements that are required to allow interactions between catalytic and carrier protein domains. Their large size coupled to this flexibility renders these multi-domain proteins very challenging for structural characterization. Here, we summarize recent studies that offer structural views of multi-domain NRPSs in various catalytically relevant conformations, thus providing an increased comprehension of their catalytic cycle. A better structural understanding of these multienzymes provides novel perspectives for their re-engineering to synthesize new bioactive metabolites.
A novel modelling and simulation approach for the hindered mobility of charged particles in biological hydrogels
Authors: Grill Maximilian J. , Eichinger Jonas F. , Koban Jonas , Meier Christoph , Lieleg Oliver , Wall Wolfgang A.
Published: May 2021

This article presents a novel computational model to study the selective filtering of biological hydrogels due to the surface charge and size of diffusing particles. It is the first model that includes the random three-dimensional fibre orientation and connectivity of the biopolymer network and that accounts for elastic deformations of the fibres by means of beam theory. As a key component of the model, novel formulations are proposed both for the electrostatic and repulsive steric interactions between a spherical particle and a beam. In addition to providing a thorough validation of the model, the presented computational studies yield new insights into the underlying mechanisms of hindered particle mobility, especially regarding the influence of the aforementioned aspects that are unique to this model. It is found that the precise distribution of fibre and thus charge agglomerations in the network have a crucial influence on the mobility of oppositely charged particles and gives rise to distinct motion patterns. Considering the high practical significance for instance with respect to targeted drug release or infection defence, the provided proof of concept motivates further advances of the model towards a truly predictive computational tool that allows a case- and patient-specific assessment for real (biological) systems.
Predation favours
Bicyclus anynana
butterflies with fewer forewing eyespots
Authors: Chan Ian Z. W. , Ngan Zhe Ching , Naing Lin , Lee Yueying , Gowri V , Monteiro Antónia
Published: May 2021

There are fewer eyespots on the forewings versus hindwings of nymphalids but the reasons for this uneven distribution remain unclear. One possibility is that, in many butterflies, the hindwing covers part of the ventral forewing at rest and there are fewer forewing sectors to display eyespots (covered eyespots are not continuously visible and are less likely to be under positive selection). A second explanation is that having fewer forewing eyespots confers a selective advantage against predators. We analysed wing overlap at rest in 275 nymphalid species with eyespots and found that many have exposed forewing sectors without eyespots: i.e. wing overlap does not constrain the forewing from having the same number or more eyespots than the hindwing. We performed two predation experiments with mantids to compare the relative fitness of and attack damage patterns on two forms of
Bicyclus anynana
butterflies, both with seven hindwing eyespots, but with two (in wild-type) or four (in Spotty) ventral forewing eyespots. Spotty experienced more intense predation on the forewings, were shorter-lived and laid fewer eggs. These results suggest that predation pressure limits forewing eyespot number in
B. anynana
. This may occur if attacks on forewing eyespots have more detrimental consequences for flight than attacks on hindwing eyespots.
Individual telomere dynamics and their links to life history in a viviparous lizard
Authors: Fitzpatrick L. J. , Olsson M. , Pauliny A. , While G. M. , Wapstra E.
Published: May 2021

Emerging patterns suggest telomere dynamics and life history are fundamentally linked in endotherms through life-history traits that mediate the processes underlying telomere attrition. Unlike endotherms, ectotherms maintain the ability to lengthen somatic telomeres throughout life and the link between life-history strategies and ectotherm telomere dynamics is unknown. In a well-characterized model system (
Niveoscincus ocellatus
), we used long-term longitudinal data to study telomere dynamics across climatically divergent populations. We found longer telomeres in individuals from the cool highlands than those from the warm lowlands at birth and as adults. The key determinant of adult telomere length across populations was telomere length at birth, with population-specific effects of age and growth on adult telomere length. The reproductive effort had no proximate effect on telomere length in either population. Maternal factors influenced telomere length at birth in the warm lowlands but not the cool highlands. Our results demonstrate that life-history traits can have pervasive and context-dependent effects on telomere dynamics in ectotherms both within and between populations. We argue that these telomere dynamics may reflect the populations' different life histories, with the slow-growing cool highland population investing more into telomere lengthening compared to the earlier-maturing warm lowland population.
The emergence of cooperation by evolutionary generalization
Authors: Geoffroy Félix , André Jean-Baptiste
Published: May 2021

In principle, any cooperative behaviour can be evolutionarily stable as long as it is incentivized by a reward from the beneficiary, a mechanism that has been called reciprocal cooperation. However, what makes this mechanism so powerful also has an evolutionary downside. Reciprocal cooperation faces a chicken-and-egg problem of the same kind as communication: it requires two functions to evolve at the same time—cooperation and response to cooperation. As a result, it can only emerge if one side first evolves for another reason, and is then recycled into a reciprocal function. Developing an evolutionary model in which we make use of machine learning techniques, we show that this occurs if the fact to cooperate and reward others’ cooperation become general abilities that extend beyond the set of contexts for which they have initially been selected. Drawing on an evolutionary analogy with the concept of generalization, we identify the conditions necessary for this to happen. This allows us to understand the peculiar distribution of reciprocal cooperation in the wild, virtually absent in most species—or limited to situations where individuals have partially overlapping interests, but pervasive in the human species.
Rapid frequency modulation in a resonant system: aerial perturbation recovery in hawkmoths
Authors: Gau Jeff , Gemilere Ryan , (FM subteam) LDS-VIP , Lynch James , Gravish Nick , Sponberg Simon
Published: May 2021

Centimetre-scale fliers must contend with the high power requirements of flapping flight. Insects have elastic elements in their thoraxes which may reduce the inertial costs of their flapping wings. Matching wingbeat frequency to a mechanical resonance can be energetically favourable, but also poses control challenges. Many insects use frequency modulation on long timescales, but wingstroke-to-wingstroke modulation of wingbeat frequencies in a resonant spring-wing system is potentially costly because muscles must work against the elastic flight system. Nonetheless, rapid frequency and amplitude modulation may be a useful control modality. The hawkmoth
Manduca sexta
has an elastic thorax capable of storing and returning significant energy. However, its nervous system also has the potential to modulate the driving frequency of flapping because its flight muscles are synchronous. We tested whether hovering hawkmoths rapidly alter frequency during perturbations with vortex rings. We observed both frequency modulation (32% around mean) and amplitude modulation (37%) occurring over several wingstrokes. Instantaneous phase analysis of wing kinematics revealed that more than 85% of perturbation responses required active changes in neurogenic driving frequency. Unlike their robotic counterparts that abdicate frequency modulation for energy efficiency, synchronous insects use wingstroke-to-wingstroke frequency modulation despite the power demands required for deviating from resonance.
Faecal metabarcoding reveals pervasive long-distance impacts of garden bird feeding
Authors: Shutt Jack D. , Trivedi Urmi H. , Nicholls James A.
Published: May 2021

Supplementary feeding of wildlife is widespread, being undertaken by more than half of households in many countries. However, the impact that these supplemental resources have is unclear, with impacts largely considered to be restricted to urban ecosystems. We reveal the pervasiveness of supplementary foodstuffs in the diet of a wild bird using metabarcoding of blue tit (
Cyanistes caeruleus
) faeces collected in early spring from a 220 km transect in Scotland with a large urbanization gradient. Supplementary foodstuffs were present in the majority of samples, with peanut (
Arachis hypogaea
) the single commonest (either natural or supplementary) dietary item. Consumption rates exhibited a distance decay from human habitation but remained high at several hundred metres from the nearest household and continued to our study limit of 1.4 km distant. Supplementary food consumption was associated with a near quadrupling of blue tit breeding density and a 5-day advancement of breeding phenology. We show that woodland bird species using supplementary food have increasing UK population trends, while species that do not, and/or are outcompeted by blue tits, are likely to be declining. We suggest that the impacts of supplementary feeding are larger and more spatially extensive than currently appreciated and could be disrupting population and ecosystem dynamics.
Contemporary and historical selection in Tasmanian devils (
Sarcophilus harrisii
) support novel, polygenic response to transmissible cancer
Authors: Stahlke Amanda R. , Epstein Brendan , Barbosa Soraia , Margres Mark J. , Patton Austin H. , Hendricks Sarah A. , Veillet Anne , Fraik Alexandra K. , Schönfeld Barbara , McCallum Hamish I. , Hamede Rodrigo , Jones Menna E. , Storfer Andrew , Hohenlohe Paul A.
Published: May 2021

Tasmanian devils (
Sarcophilus harrisii
) are evolving in response to a unique transmissible cancer, devil facial tumour disease (DFTD), first described in 1996. Persistence of wild populations and the recent emergence of a second independently evolved transmissible cancer suggest that transmissible cancers may be a recurrent feature in devils. Here, we compared signatures of selection across temporal scales to determine whether genes or gene pathways under contemporary selection (six to eight generations) have also been subject to historical selection (65–85 Myr). First, we used targeted sequencing, RAD-capture, in approximately 2500 devils in six populations to identify genomic regions subject to rapid evolution. We documented genome-wide contemporary evolution, including 186 candidate genes related to cell cycling and immune response. Then we used a molecular evolution approach to identify historical positive selection in devils compared to other marsupials and found evidence of selection in 1773 genes. However, we found limited overlap across time scales, with only 16 shared candidate genes, and no overlap in enriched functional gene sets. Our results are consistent with a novel, multi-locus evolutionary response of devils to DFTD. Our results can inform conservation by identifying high priority targets for genetic monitoring and guiding maintenance of adaptive potential in managed populations.
Host–pathogen immune feedbacks can explain widely divergent outcomes from similar infections
Authors: Ellner Stephen P. , Buchon Nicolas , Dörr Tobias , Lazzaro Brian P.
Published: May 2021

A long-standing question in infection biology is why two very similar individuals, with very similar pathogen exposures, may have very different outcomes. Recent experiments have found that even isogenic
Drosophila melanogaster
hosts, given identical inoculations of some bacterial pathogens at suitable doses, can experience very similar initial bacteria proliferation but then diverge to either a lethal infection or a sustained chronic infection with much lower pathogen load. We hypothesized that divergent infection outcomes are a natural result of mutual negative feedbacks between pathogens and the host immune response. Here, we test this hypothesis
in silico
by constructing process-based dynamic models for bacterial population growth, host immune induction and the feedbacks between them, based on common mechanisms of immune system response. Mathematical analysis of a minimal conceptual model confirms our qualitative hypothesis that mutual negative feedbacks can magnify small differences among hosts into life-or-death differences in outcome. However, explaining observed features of chronic infections requires an extension of the model to include induced pathogen modifications that shield themselves from host immune responses at the cost of reduced proliferation rate. Our analysis thus generates new, testable predictions about the mechanisms underlying bimodal infection outcomes.
Clinical utility of 16S rRNA PCR in pleural infection
Authors: Lampejo Temi , Ciesielczuk Holly , Lambourne Jonathan
Published: May 2021

Pleural infections cause major morbidity and mortality, particularly amongst paediatric and elderly populations. The aetiology is broad, but pleural culture fails to yield a causative pathogen in approximately 40 % of cases. Alternative pathogen identification methods are therefore required. The aim of the study was to investigate the yield from and impact on patient care when performing 16S rRNA PCR on culture-negative pleural fluid specimens and to determine whether any individual laboratory parameters were associated with a positive 16S rRNA PCR result. We conducted a study on 90 patients with suspected pleural infection, who had a culture-negative pleural fluid specimen, which underwent 16S rRNA PCR analysis between August 2017 and June 2019. This study was undertaken at a large NHS Trust in London, UK. Thirty-one per cent of culture-negative pleural fluid specimens tested by 16S rRNA PCR yielded a positive PCR result. Our data demonstrated that 16S rRNA PCR detected a significantly higher proportion of

Streptococcus pneumoniae

(P<0.0001) and fastidious, slow-growing and anaerobic pathogens (P=0.0025) compared with culture-based methods. Of the 25 16S rRNA PCR results that were positive for a causative pathogen, 76 % had a direct impact on clinical management. No single laboratory variable was found to be associated with a positive 16S rRNA PCR result. The findings from our real-world evaluation highlight the importance of 16S rRNA PCR in confirming pleural infection when the aetiology is unknown, and its direct, positive impact on clinical management.
Emergence of a new SARS-CoV-2 variant from GR clade with a novel S glycoprotein mutation V1230L in West Bengal, India
Authors: Sarkar Rakesh , Saha Ritubrita , Mallick Pratik , Sharma Ranjana , Kaur Amandeep , Dutta Shanta , Chawla-Sarkar Mamta
Published: May 2021

India is currently facing the devastating second wave of COVID-19 pandemic resulting in approximately 4000 deaths per day. To control this pandemic continuous mutational surveillance and genomic epidemiology of circulating strains is very important. In this study, we performed mutational analysis of the protein coding genes of SARS-CoV-2 strains (n=2000) collected during January 2021 to March 2021. Our data revealed the emergence of a new variant in West Bengal, India, which is characterized by the presence of 11 co-existing mutations including D614G, P681H and V1230L in S-glycoprotein. This new variant was identified in 70 out of 412 sequences submitted from West Bengal. Interestingly, among these 70 sequences, 16 sequences also harbored E484K in the S glycoprotein. Phylogenetic analysis revealed strains of this new variant emerged from GR clade (B.1.1) and formed a new cluster. We propose to name this variant as GRL or lineage B.1.1/S:V1230L due to the presence of V1230L in S glycoprotein along with GR clade specific mutations. Co-occurrence of P681H, previously observed in UK variant, and E484K, previously observed in South African variant and California variant, demonstrates the convergent evolution of SARS-CoV-2 mutation. V1230L, present within the transmembrane domain of S2 subunit of S glycoprotein, has not yet been reported from any country. Substitution of valine with more hydrophobic amino acid leucine at position 1230 of the transmembrane domain, having role in S protein binding to the viral envelope, could strengthen the interaction of S protein with the viral envelope and also increase the deposition of S protein to the viral envelope, and thus positively regulate virus infection. P618H and E484K mutation have already been demonstrated in favor of increased infectivity and immune invasion respectively. Therefore, the new variant having G614G, P618H, P1230L and E484K is expected to have better infectivity, transmissibility and immune invasion characteristics, which may pose additional threat along with B.1.617 in the ongoing COVID-19 pandemic in India.
Does immune recognition of SARS-CoV2 epitopes vary between different ethnic groups?
Authors: Bose Tungadri , Pant Namrata , Pinna Nishal Kumar , Bhar Subhrajit , Dutta Anirban , Mande Sharmila S.
Published: May 2021

The SARS-CoV2 mediated Covid-19 pandemic has impacted humankind at an unprecedented scale. While substantial research efforts have focused towards understand the mechanisms of viral infection and developing vaccines/ therapeutics, factors affecting the susceptibility to SARS-CoV2 infection and manifestation of Covid-19 remain less explored. Given that the Human Leukocyte Antigen (HLA) system is known to vary among ethnic populations, it is likely to affect the recognition of the virus, and in turn, the susceptibility to Covid-19. To understand this, we used bioinformatic tools to probe all SARS-CoV2 peptides which could elicit T-cell response in humans. We also tried to answer the intriguing question of whether these potential epitopes were equally immunogenic across ethnicities, by studying the distribution of HLA alleles among different populations and their share of cognate epitopes. We provide evidence that the newer mutations in SARS-CoV2 are unlikely to alter the T-cell mediated immunogenic responses among the studied ethnic populations. The work presented herein is expected to bolster our understanding of the pandemic, by providing insights into differential immunological response of ethnic populations to the virus as well as by gauging the possible effects of mutations in SARS-CoV2 on efficacy of potential epitope-based vaccines through evaluating ∼40000 viral genomes.
Feasibility and utility of rapid antigen testing for COVID-19 in a university residence: a cross sectional study
Authors: Wong Sabrina T. , Romney Marc , Matic Nancy , Haase Kristen , Ranger Manon , Dhari Ranjit , Affleck Frances , Tan Elsie , Ndateba Innocent , Tobias Erica , Saewyc Elizabeth , Schwandt Michael , Sin Don
Published: May 2021

Importance

Understanding feasibility of rapid testing in congregate living setting provides critical data to reduce the risk of outbreaks in these settings.

Objective

Use rapid antigen screening to detect SARS-CoV-2 in an asymptomatic group of university students and staff.

Design

Cross-sectional

Setting

University of British Columbia, Vancouver, Canada.

Participants

Students and staff living or working in congregate housing.

Intervention

Health care professional administered rapid antigen test

Main Outcomes and measures

Use of BD Veritor rapid antigen testing and asymptomatic participants’ experiences with rapid testing

Results

A total of 3536 BD Veritor tests were completed in 1141 unique individuals. One third of participants completed between two to four tests and 21% were screened five or more times. The mean number of tests completed per person was three. The mean length of time between those who had more than one test was seven days. There were eight false positives and 25 PCR confirmed COVID-19 positive individuals identified through this work. All individuals reported having no symptoms that they attributed to COVID-19. Almost all (n=22, 88%) COVID-19 positive cases were found in male participants. A total of 86 additional students from multiple different student residences (n=9) were asked to self-isolate while they waited for their COVID-19 diagnostic test results. An average of seven additional students positive for COVID-19 living in congregate housing were identified through contact tracing by finding one positive case.

Conclusions and relevance

Rapid testing is a relatively inexpensive and operationally easy method of identifying asymptomatic individuals with COVID-19.