Warming effects on lizard gut microbiome depend on habitat connectivity

Climate warming and landscape fragmentation are both factors well known to threaten biodiversity and to generate species responses and adaptation. However, the impact of warming and fragmentation interplay on organismal responses remains largely under-explored, especially when it comes to gut symbionts, which may play a key role in essential host functions and traits by extending its functional and genetic repertoire. Here, we experimentally examined the combined effects of climate warming and habitat connectivity on the gut bacterial communities of the common lizard (Zootoca vivipara) over three years. While the strength of effects varied over the years, we found that a 2°C warmer climate decreases lizard gut microbiome diversity in isolated habitats. However, enabling connectivity among habitats with warmer and cooler climates offset or even reversed warming effects. The warming effects and the association between host dispersal behaviour and microbiome diversity appear to be a potential driver of this interplay. This study suggests that preserving habitat connectivity will play a key role in mitigating climate change impacts, including the diversity of the gut microbiome, and calls for more studies combining multiple anthropogenic stressors when predicting the persistence of species and communities through global changes.

Demography and movement patterns of a freshwater ciliate: The influence of oxygen availability

In freshwater habitats, aerobic animals and microorganisms can react to oxygen deprivation by a series of behavioural and physiological changes, either as a direct consequence of hindered performance or as adaptive responses towards hypoxic conditions. Since oxygen availability can vary throughout the water column, different strategies exist to avoid hypoxia, including that of active 'flight' from low-oxygen sites. Alternatively, some organisms may invest in slower movement, saving energy until conditions return to more favourable levels, which may be described as a 'sit-and-wait' strategy. Here, we aimed to determine which, if any, of these strategies could be used by the freshwater ciliate Tetrahymena thermophila when faced with decreasing levels of oxygen availability in the culture medium. We manipulated oxygen flux into clonal cultures of six strains (i.e. genotypes) and followed their growth kinetics for several weeks using automated image analysis, allowing to precisely quantify changes in density, morphology and movement patterns. Oxygen effects on demography and morphology were comparable across strains: reducing oxygen flux decreased the growth rate and maximal density of experimental cultures, while greatly expanding the duration of their stationary phase. Cells sampled during their exponential growth phase were larger and had a more elongated shape under hypoxic conditions, likely mirroring a shift in resource investment towards individual development rather than frequent divisions. In addition to these general patterns, we found evidence for intraspecific variability in movement responses to oxygen limitation. Some strains showed a reduction in swimming speed, potentially associated with a 'sit-and-wait' strategy; however, the frequent alteration of movement paths towards more linear trajectories also suggests the existence of an inducible 'flight response' in this species. Considering the inherent costs of turns associated with non-linear movement, such a strategy may allow ciliates to escape suboptimal environments at a low energetic cost.

Non-genetic phenotypic variability affects populations and communities in protist microcosms

Intraspecific trait variation (ITV), potentially driven by genetic and non-genetic mechanisms, can underlie variability in resource acquisition, individual fitness and ecological interactions. Impacts of ITV at higher levels of biological organizations are hence likely, but up-scaling our knowledge about ITV importance to communities and comparing its relative effects at population and community levels has rarely been investigated. Here, we tested the effects of genetic and non-genetic ITV on morphological traits in microcosms of protist communities by contrasting the effects of strains showing different ITV levels (i.e. trait averages and variance) on population growth, community composition and biomass production. We found that genetic and non-genetic ITV can lead to different effects on populations and communities across several generations. Furthermore, the effects of ITV declined across levels of biological organization: ITV directly altered population performance, with cascading but indirect consequences for community composition and biomass productivity. Overall, these results show that the drivers of ITV can have distinct effects on populations and communities, with cascading impacts on higher levels of biological organization that might mediate biodiversity-ecosystem functioning relationships.

The macronuclear genomic landscape within Tetrahymena thermophila

The extent of intraspecific genomic variation is key to understanding species evolutionary history, including recent adaptive shifts. Intraspecific genomic variation remains poorly explored in eukaryotic micro-organisms, especially in the nuclear dimorphic ciliates, despite their fundamental role as laboratory model systems and their ecological importance in many ecosystems. We sequenced the macronuclear genome of 22 laboratory strains of the oligohymenophoran Tetrahymena thermophila, a model species in both cellular biology and evolutionary ecology. We explored polymorphisms at the junctions of programmed eliminated sequences, and reveal their utility to barcode very closely related cells. As for other species of the genus Tetrahymena, we confirm micronuclear centromeres as gene diversification centres in T. thermophila, but also reveal a two-speed evolution in these regions. In the rest of the genome, we highlight recent diversification of genes coding for extracellular proteins and cell adhesion. We discuss all these findings in relation to this ciliate's ecology and cellular characteristics.

Beyond reaction norms: the temporal dynamics of phenotypic plasticity

Phenotypic plasticity can allow organisms to cope with environmental changes. Although reaction norms are commonly used to quantify plasticity along gradients of environmental conditions, they often miss the temporal dynamics of phenotypic change, especially the speed at which it occurs. Here, we argue that studying the rate of phenotypic plasticity is a crucial step to quantify and understand its adaptiveness. Iteratively measuring plastic traits allows us to describe the actual dynamics of phenotypic changes and avoid quantifying reaction norms at times that do not truly reflect the organism's capacity for plasticity. Integrating the temporal component in how we describe, quantify, and conceptualise phenotypic plasticity can change our understanding of its diversity, evolution, and consequences.

The emerging role of lipid nanosystems and nanomicelles in liver diseases

Nanoparticles (NPs) exhibit remarkable potential in the diagnosis and treatment of various liver ailments, including primary liver cancer or hepatocellular carcinoma (HCC), liver cirrhosis, viral hepatitis, and alcoholic and non-alcoholic liver diseases. High surface area-to-volume ratio with distinct physicochemical and bio-pharmaceutical properties have contributed numerous benefits to NPs, such as high intracellular uptake and efficient drug delivery capabilities stemming from their ability to encapsulate a diverse range of drugs. Lipid-based nanosystems have demonstrated significant potential as reliable and efficient transport vehicles for a variety of actives, including small interfering RNA, targeting the liver, owing to their excellent in vivo compatibility, biodegradable nature, and non-toxic properties. Multiple aspects of various lipid-based materials, lipid nanosystems like solid lipid NPs, nanovesicles such as nanoemulsions, liposomes, and nanomicelles for liver-specific active targeting have been comprehensively reviewed. Ongoing and completed clinical trials of lipid nanosystems developed for HCC, hepatic fibrosis, and hepatitis are tabulated. Types of receptors and ligands typically used for active liver targeting in HCC are extensively discussed. The US FDA's recent approval for the use of Onpattro (Patisiran) injection to treat polyneuropathy in adult patients is indicative of the rapid development of lipid nanosystems employed for hepatic targeting. Nanoemulsions loaded with diagnostic imaging agents for multi-modal liver imaging were briefly discussed. Emerging technologies are being developed to integrate desirable properties of nanoparticles (NPs), including high stability, efficient drug loading, opsonization avoidance, active liver targeting, and facilitation of endosomal escape. Clinical translations of many lipid NPs for drug and gene therapy applications targeting different liver diseases are expected in the near future.

Resident-Disperser Differences and Genetic Variability Affect Communities in Microcosms

AbstractDispersal is a key process mediating ecological and evolutionary dynamics. Its effects on the dynamics of spatially structured systems, population genetics, and species range distribution can depend on phenotypic differences between dispersing and nondispersing individuals. However, scaling up the importance of resident-disperser differences to communities and ecosystems has rarely been considered, in spite of intraspecific phenotypic variability being an important factor mediating community structure and productivity. Here, we used the ciliate Tetrahymena thermophila, in which phenotypic traits are known to differ between residents and dispersers, to test (i) whether these resident-disperser differences affect biomass and composition in competitive communities composed of four other Tetrahymena species and (ii) whether these effects are genotype dependent. We found that dispersers led to a lower community biomass compared with residents. This effect was highly consistent across the 20 T. thermophila genotypes used, despite intraspecific variability in resident-disperser phenotypic differences. We also found a significant genotypic effect on biomass production, showing that intraspecific variability has consequences for communities. Our study suggests that individual dispersal strategy can scale up to community productivity in a predictable way, opening new perspectives to the functioning of spatially structured ecosystems.

Dispersal syndromes in challenging environments: A cross-species experiment

Dispersal is a central biological process tightly integrated into life-histories, morphology, physiology and behaviour. Such associations, or syndromes, are anticipated to impact the eco-evolutionary dynamics of spatially structured populations, and cascade into ecosystem processes. As for dispersal on its own, these syndromes are likely neither fixed nor random, but conditional on the experienced environment. We experimentally studied how dispersal propensity varies with individuals' phenotype and local environmental harshness using 15 species ranging from protists to vertebrates. We reveal a general phenotypic dispersal syndrome across studied species, with dispersers being larger, more active and having a marked locomotion-oriented morphology and a strengthening of the link between dispersal and some phenotypic traits with environmental harshness. Our proof-of-concept metacommunity model further reveals cascading effects of context-dependent syndromes on the local and regional organisation of functional diversity. Our study opens new avenues to advance our understanding of the functioning of spatially structured populations, communities and ecosystems.

Dispersal plasticity driven by variation in fitness across species and environmental gradients

Dispersal plasticity, when organisms adjust their dispersal decisions depending on their environment, can play a major role in ecological and evolutionary dynamics, but how it relates to fitness remains scarcely explored. Theory predicts that high dispersal plasticity should evolve when environmental gradients have a strong impact on fitness. Using microcosms, we tested in five species of the genus Tetrahymena whether dispersal plasticity relates to differences in fitness sensitivity along three environmental gradients. Dispersal plasticity was species- and environment-dependent. As expected, dispersal plasticity was generally related to fitness sensitivity, with higher dispersal plasticity when fitness is more affected by environmental gradients. Individuals often preferentially disperse out of low fitness environments, but leaving environments that should yield high fitness was also commonly observed. We provide empirical support for a fundamental, but largely untested, assumption in dispersal theory: the extent of dispersal plasticity correlates with fitness sensitivity to the environment.

The onset of puberty in colony-housed male and female titi monkeys (Plecturocebus cupreus): Possible effects of oxytocin treatment during peri-adolescent development

Oxytocin has been used to treat neurodevelopmental conditions in adolescent patients but possible effects on reproductive development have not been well investigated. The effects of daily intra-nasal oxytocin treatment (12-18 months of age) on puberty and fertility were studied in colony-housed, male and female titi monkeys (Plecturocebus cupreus). Body weight, urinary conjugated pregnanes and estrogens (defining cyclicity) in females, and androgens and sperm in urine of in males, were measured from 1 to 3 years of age to detect puberty. Serum testosterone was also measured in males at 13, 23 and 33 months of age and hemi-castration at 3 years of age enabled assessment of testicular morphometry and oxytocin receptor expression. An oxytocin treatment*time interaction suggested a minor, transient suppression in weight gain after treatment ended. Note that females weighed 10% less across all ages. Oxytocin-treated females exhibited early, spurious ovulations but neither regular cyclicity (≈30 months) nor pregnancies were affected by treatment. Oxytocin did not affect the pubertal increase in urinary androgen or the first appearance of sperm, which occurred as early as 15 months of age. Treatment did delay the puberty-associated rise in serum testosterone in males. All males were pubertal by 22 months and all females by 32 months of age. Although no major male or female fertility outcome was observed, oxytocin demonstrated some physiological effects through a delay of testosterone secretion in males, induction of precocious ovulation in females, and a suppression of general weight gain for the months following treatment.

Risk of pacemaker implantation after radiotherapy for breast cancer: A study based on French nationwide health care database sample

Background

Among cardiac complications of breast cancer radiotherapy (BC RT), there are very limited data on arrhythmia and conduction disorders, in particular severe cases requiring permanent pacemaker implantation (PPMI). Therefore, this exploratory study aimed to evaluate the risk of PPMI for BC patients treated with RT, compared with the general population and with BC patients not treated with RT.

Methods

The study was performed on a 1/97 representative sample of the French health care database (EGB database). Adult women with a first BC treated with or without RT between 2008 and 2016 were included, followed until 2018, and de novo PPMI were identified. We compared the PPMI incidence in BC cohort relative to the general population with standardized incidence ratio (SIR) and evaluated the risk of PPMI in RT patients compared to patients without RT with a competing risk survival analysis.

Results

A total of 3853 BCE patients were included. Among BC patients treated with RT, 28 PPMI cases were observed compared with 13 expected cases, corresponding to a SIR of 2.18 [95% CI: 1.45-3.06]. For BC patients not treated with RT, the SIR was 1.01 [95% CI: 0.40-1.90]. Patients treated with RT showed a borderline significant higher risk of PPMI compared with those not treated with RT (subdistribution Hazard Ratio = 2.08, 95% CI 0.87-4.97, p = 0.09).

Conclusions

Our exploratory findings indicate that, over the last decade in France, BC patients treated with RT appeared to be at higher risk of PPMI than general population. Further studies are needed to expand on this topic.

Dispersal syndromes can link intraspecific trait variability and meta-ecosystem functioning

Dispersal mediates the flow of organisms in meta-communities and subsequently energy and material flows in meta-ecosystems. Individuals within species often vary in dispersal tendency depending on their phenotypic traits (i.e., dispersal syndromes), but the implications of dispersal syndromes for meta-ecosystems have been rarely studied. Using empirical examples on vertebrates, arthropods, and microbes, we highlight that key functional traits can be linked to dispersal. We argue that this coupling between dispersal and functional traits can have consequences for meta-ecosystem functioning, mediating flows of functional traits and thus the spatial heterogeneity of ecosystem functions. As dispersal syndromes may be genetically determined, the spatial heterogeneity of functional traits may be further carried over across generations and link meta-ecosystem functioning to evolutionary dynamics.

Breast cancer radiotherapy and risk of pacemaker implantation: an epidemiologic analysis using the French nationwide claims database

Background

Radiotherapy (RT) is a major treatment for breast cancer (BC), but it is also associated with an increased long-term (>5–10 years) risk of cardiac complications. Specific data on cardiac arrhythmias and conduction disorders are warranted.

Purpose

To evaluate whether pacemaker (PM) implantation risk is higher in BC patients treated with RT compared to the general population or population of BC patients treated without RT.

Methods

Our study was based on the Echantillon Généraliste de Bénéficiaires (EGB), the 1/97 random sample of the French nationwide health insurance claims database. The population of patients treated for BC consisted of adult women with a first BC identified by the ICD-10 diagnosis codes between 2008 and 2016, and followed through 2018. PM implantations and RT were identified with medical procedures codes in the french Common Classification of Medical Procedures (CCAM). For each year from 2008 to 2018, the reference population included all adult women of the EGB database. History of PM or BC was an exclusion criteria. Annual incidence rates of PM implantations were evaluated between 2008 and 2018 in the reference populations. The number of PM cases observed in BC patients at least one year after BC diagnosis was compared with the expected number of PM cases calculated by using reference incidence rates with age standardization. We then computed the standardized incidence ratio (SIR) as the ratio of the observed number of PM to the expected number of PM, with 95% confidence intervals (CIs). Thereafter, a survival analysis was performed in BC patients using a Cox regression model (Hazard Ratio – HR) in order to evaluate the risk of PM associated with treatment including RT (RT) compared with treatment not including RT (no RT).

Results

A total of 3,853 patients were included in the population of patients treated for BC between 2008 and 2016 with a mean age of 60 years old and a mean follow-up of 5.6 years. In this population, 35 cases of PM were observed, compared with 19.9 expected cases of PM, corresponding to a significant SIR=1.76 (95% CI: 1.22 - 2.39). This excess risk was carried by the RT group of 2973 patients (77% of BC population): 28 observed PM vs 12.9 expected, SIR=2.18 (95% CI: 1.45–3.06). In Cox regression analysis, after adjustment on age, RT was associated with an increased risk of PM compared with no RT, but this result did not reach statistical significance (HR=1.73; p-value=0.21).

Conclusion

Based on our study, BC patients receiving RT appeared to be at higher risk of PM implantation than general female population and BC patients without RT, illustrating a potential association between cardiac exposure during BC RT and conduction disorders.

Funding Acknowledgement

Type of funding sources: None.

Impact of transcatheter aortic valve implantations on temporal trends of pacemaker implantations among French octogenarians: a nation-wide cohort study over the period 2008–2018

Background

The indications for permanent pacemaker implantation (PPMI) are strongly associated with age, with the highest rates for octogenarians (>80 years old). Over the last decade, impact of aging on temporal trends in PPMI rates among octogenarians is questionable. In the 2010's, transcatheter aortic valve implantation (TAVI) has emerged for inoperable or high-risk patients, mainly octogenarians, with an exponential increase over years. PPMI is a common short-term complication after TAVI procedure. Many studies have explored these post-TAVI PPMI in terms of incidence, timing and outcomes of PPMI following TAVI, but there are no data on the impact of TAVI on PPMI temporal trend at a nationwide scale.

Purpose

To evaluate whether PPMI in octogenarians have increased during the last decade, independently from age and sex, on a nationwide scale. Eventually, to estimate the potential contribution of TAVI in PPMI increase in this setting.

Methods

Our study was based on octogenarians from the Echantillon Généraliste de Bénéficiaires, the 1/97 random sample of the French nationwide health insurance claims database. Between 2008 and 2018, we identified de novo PPMI and TAVI with medical procedures codes in the French Common Classification of Medical Procedures (CCAM). Annual incidence rates of PPMI were evaluated between 2008 and 2012 (preTAVI-period). The number of observed PPMI cases, O, in the period 2013–2018 (TAVI-period) was compared with the expected number of PPMI cases, E, calculated by using 2008–2012 incidence rates with age and sex standardization. We then computed the standardized incidence ratio (SIR) of the observed number of PPMI to the expected number of PPMI (O/E), with 95% confidence intervals (CIs). Thereafter, we evaluated the contribution of post-TAVI PPMI in the number of excess cases of PPMI (O-E) for the period 2013–2018.

Results

The population of octogenarians increased from 23,822 in 2008 to 33,752 in 2018. In 2008, 130 PPMI were observed (546/100,000 inhabitants) reaching 228 PPMI (676/100,000) in 2018 with a marked increase in rates from the year 2012. During the period 2013–2018, for all octogenarians, 1242 cases of PPMI were observed, compared with 1171.3 expected cases of PPMI, corresponding to a significant SIR=1.06 (95% CI: 1.01–1.12). For the subpopulation of octogenarians without TAVI, no excess risk was observed with a SIR=1.01 (95% CI: 0.95–1.06). Among the excess cases of PPMI observed in 2013–2018 in all octogenarians, 72% were post-TAVI PPMI.

Conclusion

Based on our study, the number of observed PPMI in octogenarians in period 2013–2018 is 6% higher than the number we would expect. Nearly three-quarter of these excess cases are attributable to TAVI complication.

Funding Acknowledgement

Type of funding sources: None.

Phenotypic plasticity can reverse the relative extent of intra- and interspecific variability across a thermal gradient

Intra- and interspecific variability can both ensure ecosystem functions. Generalizing the effects of individual and species assemblages requires understanding how much within and between species trait variation is genetically based or results from phenotypic plasticity. Phenotypic plasticity can indeed lead to rapid and important changes of trait distributions, and in turn community functionality, depending on environmental conditions, which raises a crucial question: could phenotypic plasticity modify the relative importance of intra- and interspecific variability along environmental gradients? We quantified the fundamental niche of five genotypes in monocultures for each of five ciliate species along a wide thermal gradient in standardized conditions to assess the importance of phenotypic plasticity for the level of intraspecific variability compared to differences between species. We showed that phenotypic plasticity strongly influences trait variability and reverses the relative extent of intra- and interspecific variability along the thermal gradient. Our results show that phenotypic plasticity may lead to either increase or decrease of functional trait variability along environmental gradients, making intra- and interspecific variability highly dynamic components of ecological systems.

Assessing the probability of having attained 16 years of age in juveniles using third molar development in a sample of South Indian population

Juvenile crime or delinquency has been increasing at an alarming rate in recent times. In many countries, including India, the minimum age for criminal responsibility is 16 years. The present study aimed to estimate the probability of a south Indian adolescent either being or being older than the legally relevant age of 16 years using Demirjian's tooth formation stages. Orthopantomograms (OPG) of 640 south Indian adolescents (320 boys and 320 girls) aged between 12 and 20 years were retrospectively analyzed. In each OPG, Demirjian's formation stage of the mandibular left third molar was recorded and the data was subjected to statistical analysis. Descriptive and Pearsons correlation statistics were performed. The empirical probabilities were provided relative to the medico-legal question of predicting 16 years of age. The distribution of age throughout the 10th, 25th, 50th, 75th and 90th percentile follows a logical distribution pattern horizontally and vertically. Pearson's correlation statistics showed a strong positive correlation between the Demirjian's stages and age for both sexes. Therefore, it can be concluded that stage "F" can be used to predict the attainment of age equal to or older than 16 years with a probability of 93.9% for boys and 96.6% for girls.

Covid-19 presentation among symptomatic healthcare workers in Ireland

BACKGROUND

It is recognized that healthcare workers (HCWs) are at high risk of contracting Covid-19. It is incumbent on occupational health staff to recognize potential symptoms of Covid-19 among HCWs.

AIMS

The aims of the study were to describe the presenting symptoms of HCWs who developed Covid-19 in Ireland, and to estimate the odds of specific symptoms being associated with a positive Covid-19 polymerase chain reaction (PCR) result.

METHODS

A retrospective chart review of all symptomatic HCWs who self-presented for Covid-19 testing in Cork from March to May 2020 was conducted. A sex-matched case-control study was carried out to compare presenting features among those who tested positive compared to those who tested negative. Univariate and multivariable-adjusted conditional logistic regression models were run using Stata 15.0 to identify the symptoms associated with positive Covid-19 swab results.

RESULTS

Three hundred and six HCWs were included in the study; 102 cases and 204 controls. Common presenting features among cases were fever/chills (55%), cough (44%) and headache (35%). The symptoms which were significantly associated with a positive Covid-19 swab result were loss of taste/smell (adjusted odds ratio [aOR] 12.15, 95% confidence interval [CI] 1.36-108.79), myalgia (aOR 2.36, 95% 1.27-4.38), fatigue (aOR 2.31, 95% CI 1.12-4.74), headache (aOR 2.11, 95% CI 1.19-3.74) and fever/chills (aOR 1.88, 95% CI 1.12-3.15).

CONCLUSIONS

Fever, fatigue, myalgia, loss of taste/smell and headache were associated with increased odds of a Covid-19 diagnosis among symptomatic self-referred HCWs compared with those had negative swab results. Testing criteria for HCWs should reflect the broad range of possible symptoms of Covid-19.

Maternal and personal information mediates the use of social cues about predation risk

Organisms can gain information about predation risks from their parents, their own personal experience, and their conspecifics and adjust their behavior to alleviate these risks. These different sources of information can, however, provide conflicting information due to spatial and temporal variation of the environment. This raises the question of how these cues are integrated to produce adaptive antipredator behavior. We investigated how common lizards (Zootoca vivipara) adjust the use of conspecific cues about predation risk depending on whether the information is maternally or personally acquired. We experimentally manipulated the presence of predator scent in gestating mothers and their offspring in a full-crossed design. We then tested the consequences for social information use by monitoring offspring social response to conspecifics previously exposed to predator cues or not. Lizards were more attracted to the scent of conspecifics having experienced predation cues when they had themselves no personal information about predation risk. In contrast, they were more repulsed by conspecific scent when they had personally obtained information about predation risk. However, the addition of maternal information about predation risk canceled out this interactive effect between personal and social information: lizards were slightly more attracted to conspecific scent when these two sources of information about predation risk were in agreement. A chemical analysis of lizard scent revealed that exposure to predator cues modified the chemical composition of lizard scents, a change that might underlie lizards’ use of social information. Our results highlight the importance of considering multiple sources of information while studying antipredator defenses.

Characterization of cultural traits and fungicidal activity of strains belonging to the fungal genus Chaetomium

AIMS

Compare and characterize Chaetomium strains with special regard to their potentialities as biocontrol agents.

METHODS AND RESULTS

Twelve strains of the fungal genus Chaetomium from diverse ecological niches were identified as belonging to six different species. Large differences were observed between the strains with regard to temperature requirements for mycelial growth and pigmentation of culture filtrates. Culture filtrates and ethyl acetate extracts were assayed for fungicidal effects against important phytopathogens both on agar media and in multiwell plates. The samples from Chaetomium globosum were particularly active against Botrytis cinerea, Pyrenophora graminea and Bipolaris sorokiniana, while those from C. cochliodes and C. aureum were inhibitory towards Phytophthora infestans, and P. infestans and Fusarium culmorum respectively. To narrow down the active principle, the most promising extracts were separated by preparative HPLC and the resulting fractions tested in bioassays. Chaetoglobosins were identified as active compounds produced by C. globosum.

CONCLUSIONS

The bioassays revealed C. aureum and C. cochliodes as promising candidates for use in biocontrol. Both showed remarkably good activity against the prominent plant pathogen P. infestans.

SIGNIFICANCE AND IMPACT OF THE STUDY

We provide the first systematic study comparing six different Chaetomium species with regard to their use as biocontrol agents.

COVID-19-related intracranial imaging findings: a large single-centre experience

AIM

To describe the neuroradiological changes in patients with coronavirus disease 2019 (COVID-19).

MATERIALS AND METHODS

A retrospective review was undertaken of 3,403 patients who were confirmed positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and admitted to Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK between 1 March 2020 and 31 May 2020, and who underwent neuroimaging. Abnormal brain imaging was evaluated in detail and various imaging patterns on magnetic resonance imaging MRI were identified.

RESULTS

Of the 3,403 patients with COVID-19, 167 (4.9%) had neurological signs or symptoms warranting neuroimaging. The most common indications were delirium (44/167, 26%), focal neurology (37/167, 22%), and altered consciousness (34/167, 20%). Neuroimaging showed abnormalities in 23% of patients, with MRI being abnormal in 20 patients and computed tomography (CT) in 18 patients. The most consistent neuroradiological finding was microhaemorrhage with a predilection for the splenium of the corpus callosum (12/20, 60%) followed by acute or subacute infarct (5/20, 25%), watershed white matter hyperintensities (4/20, 20%), and susceptibility changes on susceptibility-weighted imaging (SWI) in the superficial veins (3/20, 15%), acute haemorrhagic necrotising encephalopathy (2/20, 10%), large parenchymal haemorrhage (2/20, 10%), subarachnoid haemorrhage (1/20, 5%), hypoxic–ischaemic changes (1/20, 5%), and acute disseminated encephalomyelitis (ADEM)-like changes (1/20, 5%).

CONCLUSION

Various imaging patterns on MRI were observed including acute haemorrhagic necrotising encephalopathy, white matter hyperintensities, hypoxic-ischaemic changes, ADEM-like changes, and stroke. Microhaemorrhages were the most common findings. Prolonged hypoxaemia, consumption coagulopathy, and endothelial disruption are the likely pathological drivers and reflect disease severity in this patient cohort.

Occupational low-dose irradiation and cancer risk among medical radiation workers

Background

Medical workers are the largest group of workers occupationally exposed to low doses of ionizing radiation (IR) worldwide.

Aims

This review presents all the cohorts of medical workers exposed in the world and summarizes cancer risks associated with radiation exposure in this population.

Methods

Epidemiological studies on health professionals exposed to IR published from 1975 to 2019 were reviewed. Strength of evidence was assessed according to the modified Royal College of General Practitioners three-star system.

Results

Among the 16 epidemiological studies focusing on cancers from 11 cohorts among medical staff exposed to radiation, higher risks of cancer were observed for pre-1950 exposure and for medical workers who performed fluoroscopically guided interventional procedures or radionuclides procedures compared to those who did not. However, strength of evidence supporting the associations remains moderate as several methodological limits including the lack of dosimetry data, lifestyle factors and recent updates may obscure the link between medical occupational exposure and cancer occurrence.

Conclusions

Excess risk of cancer is suspected for high and former exposures. The more highly exposed professions, i.e. interventional physicians and nuclear medicine workers, should be monitored carefully. Collaborative projects aiming to increase the quantity and quality of information of the studied populations would be a key point

Fragmentation mediates thermal habitat choice in ciliate microcosms

Habitat fragmentation is expected to reduce dispersal movements among patches as a result of increased inter-patch distances. Furthermore, since habitat fragmentation is expected to raise the costs of moving among patches in the landscape, it should hamper the ability or tendency of organisms to perform informed dispersal decisions. Here, we used microcosms of the ciliate Tetrahymena thermophila to test experimentally whether habitat fragmentation, manipulated through the length of corridors connecting patches differing in temperature, affects habitat choice. We showed that a twofold increase of inter-patch distance can as expected hamper the ability of organisms to choose their habitat at immigration. Interestingly, it also increased their habitat choice at emigration, suggesting that organisms become choosier in their decision to either stay or leave their patch when obtaining information about neighbouring patches gets harder. This study points out that habitat fragmentation might affect not only dispersal rate but also the level of non-randomness of dispersal, with emigration and immigration decisions differently affected. These consequences of fragmentation might considerably modify ecological and evolutionary dynamics of populations facing environmental changes.

Surgical management of oral submucous fibrosis with "Seagull-nasolabial flap" combined with short-term oral pentoxifylline for preventing relapse

The aim of the study was to evaluate the effectiveness of seagull-shaped nasolabial flap (NLF) along with adjunctive short-term oral pentoxifylline in the surgical reconstruction of oral sub mucous fibrosis (OSMF) following fibrotomy. We retrospectively evaluated 18 patients with grade IV oral sub mucous fibrosis treated by NLF. There were 3 females and 15 males. All patients were classified as stage IV OSMF with a mean preoperative mouth opening of 8.11±3.38mm. Postoperatively, patients were administered 400mg of pentoxifylline (PTX) thrice daily for 3 months. Patients were followed up at one month, six months and one year. Mouth opening, presence or absence of malignant transformation, relapse and complications were recorded at each follow-up. We found statistically significant increase in mouth opening from 8.11±3.3 to 37.67±3.74 in the postoperative period. The complications associated with NLF were very minimal. The PTX was well tolerated by all the patients. There was no incidence of relapse or rebound fibrosis seen in our series. To the best of our knowledge, this is the first time that oral pentoxifylline has been administered along with surgical treatment of oral submucous fibrosis to prevent relapse. The use of oral PTX as an adjunct along with surgical reconstruction in OSMF improves mouth opening, reduces burning sensation and relapse.

Cerebral phaeohyphomycosis due to Cladophialophora bantiana in a French Guianese child

We report a case of cerebral phaeohyphomycosis, a fungal brain infection due to a dark (dematiaceous) fungi in a 6-year-old French Guyanese boy. The child presented fever and drowsiness due to several paraventricular brain abscesses. Neurological surgeries were performed to reduce intracranial hypertension and to obtain abscess biopsies. Mycological cultures of intraoperative samples led to the diagnosis of cerebral phaeohyphomycosis due to Cladophialophora bantiana. The patient neurological status deteriorated and remained critical after several weeks of combination antifungal therapy with voriconazole 8mg/kg/day, liposomal amphotericin B 10mg/kg/day and flucytosine 200mg/kg/day. A complete surgical resection was not possible because of multiple small abscesses. A multidisciplinary ethical staff decided on home medical care with palliative ventriculoperitoneal shunt, nasogastric feeding and analgesics. One year later, the patient's neurological condition had improved and cerebral lesions had regressed, while he had not received any antifungal treatment but only traditional medicines. Cerebral phaeohyphomycosis are rare diseases affecting immunocompromised but also apparently non-immunocompromised patients, as in this case. A complete surgical resection is not always possible and mortality rates are high in spite of treatments with a combination of antifungals. The diagnosis may be difficult because of these dematiaceous fungi's slowly growing and their potential pathogenicity for laboratory staff.

Personalised treatments for acute whiplash injuries: A pilot study of nested N-of-1 trials in a multiple baseline single-case experimental design

BACKGROUND

Whiplash associated disorder (WAD), a common and disabling condition, incurs huge burden and costs to Australia. Yet, current treatments for whiplash are not very effective; improved outcomes are urgently needed. Clinical guidelines recommend simple analgesia (paracetamol and non-steroidal anti-inflammatory drugs) but there have been no trials of guideline-recommended drugs. This study will investigate the effectiveness of evidence-based advice (EBA), paracetamol, naproxen, and both paracetamol and naproxen, in reducing daily neck pain and preventing chronic neck pain after whiplash injury.

METHODS

This study is a pilot series of multi-cycle, double-blinded, randomised N-of-1 trials, nested in a multiple baseline design. The design will comprise three baselines of 5, 8 or 11 days duration. Post enrolment, participants will be randomly assigned to one of the baselines. Fifteen participants with acute (<2 weeks) Grade II WAD, experiencing at least moderate pain (NRS: ≥ 5/10), and at risk of poor recovery will be recruited from hospitals in Queensland, Australia, and through local physiotherapists. Patients will receive EBA plus a randomised sequence of three cycles of ten day treatment triplets (paracetamol designated as a C phase, naproxen, designated as a D phase, and both paracetamol and naproxen, designated as an E phase).

DISCUSSION

We will test the effects of different treatments on the primary outcome of average neck pain intensity collected daily and at 4 and 7 months post-injury. Secondary outcomes, including disability, depression, post-traumatic stress symptoms, pain catastrophizing, and feasibility of study procedures, will also be evaluated. The results of this study will inform a larger trial aiming to strengthen the evidence on EBA and simple analgesics for WAD.

TRIAL REGISTRATION

Clinical Trials Primary Registry: Australian and New Zealand Clinical Trials Registry.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12618001291279.

DATE OF REGISTRATION

31/07/2018.

PRIMARY TRIAL SPONSOR

The University of Queensland, Brisbane QLD 4072 Australia.

FUNDING

The University of Queensland.

Altered trophic interactions in warming climates: consequences for predator diet breadth and fitness

Species interactions are central in predicting the impairment of biodiversity with climate change. Trophic interactions may be altered through climate-dependent changes in either predator food preferences or prey communities. Yet, climate change impacts on predator diet remain surprisingly poorly understood. We experimentally studied the consequences of 2°C warmer climatic conditions on the trophic niche of a generalist lizard predator. We used a system of semi-natural mesocosms housing a variety of invertebrate species and in which climatic conditions were manipulated. Lizards in warmer climatic conditions ate at a greater predatory to phytophagous invertebrate ratio and had smaller individual dietary breadths. These shifts mainly arose from direct impacts of climate on lizard diets rather than from changes in prey communities. Dietary changes were associated with negative changes in fitness-related traits (body condition, gut microbiota) and survival. We demonstrate that climate change alters trophic interactions through top-predator dietary shifts, which might disrupt eco-evolutionary dynamics.

Variability in Dispersal Syndromes Is a Key Driver of Metapopulation Dynamics in Experimental Microcosms

Evolutionary ecology studies have increasingly focused on the impact of intraspecific variability on population processes. However, the role such variation plays in the dynamics of spatially structured populations and how it interacts with environmental changes remains unclear. Here we experimentally quantify the relative importance of intraspecific variability in dispersal-related traits and spatiotemporal variability of environmental conditions for the dynamics of two-patch metapopulations using clonal genotypes of a ciliate in connected microcosms. We demonstrate that in our simple two-patch microcosms, differences among genotypes are at least as important as spatiotemporal variability of resources for metapopulation dynamics. Furthermore, we show that an important proportion of this effect results from variability of dispersal syndromes. These syndromes can therefore be as important for metapopulation dynamics as spatiotemporal variability of environmental conditions. This study demonstrates that intraspecific variability in dispersal syndromes can be key in the functioning of metapopulations facing environmental changes.

Habitat fragmentation experiments on arthropods: what to do next?

Habitat fragmentation has the potential to influence ecological and evolutionary dynamics in various ways. Fragmentation experiments explore these multiple influences and the underlying mechanisms. We review experiments used in arthropods and highlight gaps in biological focus, methodology and questions addressed. While the consequences on community structure were often reported, fewer studies focused on ecosystem functions and evolutionary processes, with striking gaps on genetic and eco-evolutionary dynamics. Regarding fragmentation components, matrix quality was often overlooked while inter-patch (and source-patch) distance was the most studied component. The identified gaps outlined our need to study fragmentation at different time-scales, and on teasing apart the respective roles of each fragmentation component on each eco-evolutionary process.