A taste of space: Remote animal observations and discrete-choice models provide new insights into foraging and density dynamics for a large subarctic herbivore

Competition for resources and space can drive forage selection of large herbivores from the bite through the landscape scale. Animal behaviour and foraging patterns are also influenced by abiotic and biotic factors. Fine-scale mechanisms of density-dependent foraging at the bite scale are likely consistent with density-dependent behavioural patterns observed at broader scales, but few studies have directly tested this assertion. Here, we tested if space use intensity, a proxy of spatiotemporal density, affects foraging mechanisms at fine spatial scales similarly to density-dependent effects observed at broader scales in caribou. We specifically assessed how behavioural choices are affected by space use intensity and environmental processes using behavioural state and forage selection data from caribou (Rangifer tarandus granti) observed from GPS video-camera collars using a multivariate discrete-choice modelling framework. We found that the probability of eating shrubs increased with increasing caribou space use intensity and cover of Salix spp. shrubs, whereas the probability of eating lichen decreased. Insects also affected fine-scale foraging behaviour by reducing the overall probability of eating. Strong eastward winds mitigated negative effects of insects and resulted in higher probabilities of eating lichen. At last, caribou exhibited foraging functional responses wherein their probability of selecting each food type increased as the availability (% cover) of that food increased. Space use intensity signals of fine-scale foraging were consistent with density-dependent responses observed at larger scales and with recent evidence suggesting declining reproductive rates in the same caribou population. Our results highlight potential risks of overgrazing on sensitive forage species such as lichen. Remote investigation of the functional responses of foraging behaviours provides exciting future applications where spatial models can identify high-quality habitats for conservation.

Optimal trade-off between boosted tolerance and growth fitness during adaptive evolution of yeast to ethanol shocks

BACKGROUND

The selection of Saccharomyces cerevisiae strains with higher alcohol tolerance can potentially increase the industrial production of ethanol fuel. However, the design of selection protocols to obtain bioethanol yeasts with higher alcohol tolerance poses the challenge of improving industrial strains that are already robust to high ethanol levels. Furthermore, yeasts subjected to mutagenesis and selection, or laboratory evolution, often present adaptation trade-offs wherein higher stress tolerance is attained at the expense of growth and fermentation performance. Although these undesirable side effects are often associated with acute selection regimes, the utility of using harsh ethanol treatments to obtain robust ethanologenic yeasts still has not been fully investigated.

RESULTS

We conducted an adaptive laboratory evolution by challenging four populations (P1-P4) of the Brazilian bioethanol yeast, Saccharomyces cerevisiae PE-2_H4, through 68-82 cycles of 2-h ethanol shocks (19-30% v/v) and outgrowths. Colonies isolated from the final evolved populations (P1c-P4c) were subjected to whole-genome sequencing, revealing mutations in genes enriched for the cAMP/PKA and trehalose degradation pathways. Fitness analyses of the isolated clones P1c-P3c and reverse-engineered strains demonstrated that mutations were primarily selected for cell viability under ethanol stress, at the cost of decreased growth rates in cultures with or without ethanol. Under this selection regime for stress survival, the population P4 evolved a protective snowflake phenotype resulting from BUD3 disruption. Despite marked adaptation trade-offs, the combination of reverse-engineered mutations cyr1A1474T/usv1Δ conferred 5.46% higher fitness than the parental PE-2_H4 for propagation in 8% (v/v) ethanol, with only a 1.07% fitness cost in a culture medium without alcohol. The cyr1A1474T/usv1Δ strain and evolved P1c displayed robust fermentations of sugarcane molasses using cell recycling and sulfuric acid treatments, mimicking Brazilian bioethanol production.

CONCLUSIONS

Our study combined genomic, mutational, and fitness analyses to understand the genetic underpinnings of yeast evolution to ethanol shocks. Although fitness analyses revealed that most evolved mutations impose a cost for cell propagation, combination of key mutations cyr1A1474T/usv1Δ endowed yeasts with higher tolerance for growth in the presence of ethanol. Moreover, alleles selected for acute stress survival comprising the P1c genotype conferred stress tolerance and optimal performance under conditions simulating the Brazilian industrial ethanol production.

IL-10 dependent adaptation allows macrophages to adjust inflammatory responses to TLR4 stimulation history

During an infection, innate immune cells must adjust nature and strength of their responses to changing pathogen abundances. To determine how stimulation of the pathogen sensing TLR4 shapes subsequent macrophage responses, we systematically varied priming and restimulation concentrations of its ligand KLA. We find that different priming strengths have very distinct effects at multiple stages of the signaling response, including receptor internalization, MAPK activation, cytokine and chemokine production, and nuclear translocation and chromatin association of NFκB and IκB members. In particular, restimulation-induced TNF-α production required KLA doses equal to or greater than those used for prior exposure, indicating that macrophages can detect and adaptively respond to changing TLR4 stimuli. Interestingly, while such adaptation was dependent on the anti-inflammatory cytokine IL-10, exogenous concentrations of IL-10 corresponding to those secreted after strong priming did not exert suppressive effects on TNF-α without such prior priming, confirming the critical role of TLR4 stimulation history.

Patterns of Failure in Pediatric and Young Adult Rhabdomyosarcoma

PURPOSE/OBJECTIVE(S)

To characterize patterns of failure in pediatric and young adult patients with rhabdomyosarcoma (RMS) from a single institution with over 20 years of experience.

MATERIALS/METHODS

Patients diagnosed with RMS from 2000 to 2022 were identified retrospectively. Time to failure was calculated from diagnosis. Local only failure was defined as first failure at the primary site without distant failure. Distant failure was defined as first failure outside of the primary site with or without local failure. Cumulative incidence (CI) of failure was calculated using death as a competing risk. Fine-Gray regression was used to evaluate impact of prognostic factors.

RESULTS

Ninety-five patients were eligible. Median age was 7.28 years (range 0 - 35 years), 41% of patients were >10 years old. Median follow up was 33.3 months. Approximately half (n = 47, 49.5%) of the tumors demonstrated alveolar histology. FOXO1 fusion status was available in 76 (80%) patients, of which 7 out of 37 alveolar tumors (18.9%) were FOXO1 fusion negative. The majority of tumors presented with unfavorable primary site (n = 72, 75.8%) and advanced stage (Stage III and IV, n = 72, 75.8%). The 5-yr CI of local only failure and distant failure for the entire cohort was 19.0% (95% CI 11.3, 28.3) and 34.6% (24.0, 45.5%), respectively. The predominant pattern of failure by Group was: Groups 1&2: Local only (5yr CI 14.8%), Group 3: Distant (5yr CI: 25.9%), Group 4: Distant (5yr CI: 67.6%). CI of distant failure by primary site was higher in perianal/gluteal (n = 2/5, 5yr CI 60.0%) and extremity (n = 8/19, 5yr CI 45.9%) sites. Of the 28 distant failures, 10 (36%) also had a local failure component. CI of local only failure by primary site was higher in parameningeal head and neck (n = 6/25, 5yr CI 30%) and bladder/prostate (n = 2/12, 5yr CI 23%) sites. The following were associated with an increased CI of distant failures: increasing age (HR 1.08, p<0.01), alveolar vs. embryonal histology (HR 3.01, p = 0.0095), FOXO1 fusion positive vs. negative (HR 2.8, p = 0.02) and Group IV vs. Groups I/II (HR 7.7, p = 0.0007). FOXO1 fusion and alveolar histology were associated with older age and Group IV, both of which were independently associated with increased distant failure on multivariate analysis.

CONCLUSION

Failures were predominantly distant in older patients and patients with Group IV RMS, both of which were associated with FOXO1 fusion and alveolar histology, highlighting the need to improve therapies in this population. Local only failures were highest in parameningeal head and neck and bladder/prostate primaries, highlighting the need to improve local control strategies at these sites.

EasyGuide Plasmids Support in Vivo Assembly of gRNAs for CRISPR/Cas9 Applications in Saccharomyces cerevisiae

Most CRISPR/Cas9 applications in yeast rely on a plasmid-based expression of Cas9 and its guide RNA (gRNA) containing a 20-nucleotides (nts) spacer tailored to each genomic target. The lengthy assembly of this customized gRNA requires at least 3-5 days for its precloning in Escherichia coli, purification, validation, and cotransformation with Cas9 into a yeast strain. Here, we constructed a series of 12 EasyGuide plasmids to simplify CRISPR/Cas9 applications in Saccharomyces cerevisiae. The new vectors provide templates for generating PCR fragments that can assemble up to six functional gRNAs directly into yeasts via homologous recombination between the 20-nts spacers. By dispensing precloning in E. coli, yeast in vivo gRNA assembly significantly reduces the CRISPR/Cas9 experimental workload. A highly efficient yeast genome editing procedure, involving PCR amplification of gRNAs and donors, followed by their transformation into a Cas9-expressing strain, can be easily accomplished through a quick protocol.

POS0993 RADIOLOGICAL CERVICAL INVOLVMENT IN ANKYLOSING SPONDYLITIS

Background

Cervical involvement in ankylosing spondylitis (AS) is particularly disabling and has been poorly studied yet. Actual radiologic scoring design to assess disease progression does not provide a comprehensive picture of the cervical involvement in AS. [1] Association with clinical features such as psoriasis are discussed.

Objectives

We aimed to assess radiographic features of cervical involvement in AS and clinico-biological parameters associated with this specific radiographic location.

Methods

Cross-sectional study based on radiographic analysis of a subgroup of patients included in the French BambooSpine cohort, originally designed to study the genetic risk factors of AS structural severity. The analysis was based on patients included in Parisian hospitals to have access to images of the entire spine on the Picture Archiving and Communication System (PACS) shared by all University Hospitals in Paris. A double reading of the images was performed by a rheumatologist/radiologist pair until consensus was reached, to identify syndesmophytes, zygapophyseal joint (ZJ) involvement and posterior ligament structures (PLS) at each cervical level, syndesmophytes in the thoracic region, and ZJ and PLS involvement in the lumbar region.

Results

Of the 113 assessed patients, 101 were men, mean age 53 years (+/- 11 years) with 27 years (+/- 13 years) of disease duration (Table 1). Of those whose HLA B27 status was known, 85% (70/82) were carriers. Among 86 patients with radiological cervical involvement, 83% had syndesmophytes, 86% had ZJ involvement and 24% had PLS involvement. In the cervical region, 13 patients (15%) had zygapophyseal fusion without syndesmophytes. 26/113 patients were completely free of any cervical involvement while 30/113 had a maximal cervical involvement (anterior and posterior). In univariate analyses, HLA-B27 was significantly associated with ZJ involvement at the cervical and lumbar level (p=0.016). Cervical involvement of any type was not associated with psoriasis. Low educational level (not beyond secondary school) was significantly associated with syndesmophytic involvement (p=0.035). There was a non-significant trend for an association between arthritis and ZJ involvement.

Table 1.

Clinical features

Men (n,%)101/11389,4%Age at diagnosis (mean, SD)31,211,68Duration of evolution (mean, SD)27,013,0Smoking ever (n,%)65/11258,0 %Chronic Back Pain (for > 3 months) (n,%)109/11396,5%Chest pain45/11040,9%Buttock pain78/10971,6%Arthritis36/11132,4%Enthesitis38/11233,9%Dactylitis6/1115,4%HLA B2770/8285,4%CRP87/10384,5%X ray sacro-iliitis112/112100%Personnal history -Uveitis41/11336,3% -Inflammatory bowel disease13/11311,5% -Reactive arthritis2/1121,8% -Psoriasis19/11117,1%

Conclusion

Cervical involvement was very frequent (76% of this severe AS population) but not associated with psoriasis, as usually thought. Zygapophyseal involvement was present in 86 % of cases and exclusive in 15 % of cases. This latter radiological form of the disease, i.e. without syndesmophytes, is usually more difficult to diagnose, and should be systematically assessed among AS patients with cervical pain and/or patients with reduced cervical mobility.

References

[1]Wanders AJB, Landewé RBM, Spoorenberg A, et al. What is the most appropriate radiologic scoring method for ankylosing spondylitis? Arthritis & Rheumatism 2004

Disclosure of Interests

None declared

MR Imaging Differences in the Circle of Willis between Healthy Children and Adults

BACKGROUND AND PURPOSE

Asymmetries in the circle of Willis have been associated with several conditions, including migraines and stroke, but they may also be age-dependent. This study examined the impact of age and age-dependent changes in cerebral perfusion on circle of Willis anatomy in healthy children and adults.

MATERIALS AND METHODS

We performed an observational, cross-sectional study of bright and black-blood imaging of the proximal cerebral vasculature using TOF-MRA and T2 sampling perfection with application-optimized contrasts by using different flip angle evolution (T2-SPACE) imaging at the level of the circle of Willis in 23 healthy children and 43 healthy adults (4-74 years of age). We compared arterial diameters measured manually and cerebral perfusion via pseudocontinuous arterial spin-labeling between children and adults.

RESULTS

We found that the summed cross-sectional area of the circle of Willis is larger in children than in adults, though the effect size was smaller with T2-SPACE-based measurements than with TOF-MRA. The circle of Willis is also more symmetric in children, and nonvisualized segments occur more frequently in adults than in children. Moreover, the size and symmetry of the circle of Willis correlate with cerebral perfusion.

CONCLUSIONS

Our results demonstrate that the circle of Willis is different in size and symmetry in healthy children compared with adults, likely associated with developmental changes in cerebral perfusion. Further work is needed to understand why asymmetric vasculature develops in some but not all adults.

Comparative Genomics Supports That Brazilian Bioethanol Saccharomyces cerevisiae Comprise a Unified Group of Domesticated Strains Related to Cachaça Spirit Yeasts

Ethanol production from sugarcane is a key renewable fuel industry in Brazil. Major drivers of this alcoholic fermentation are Saccharomyces cerevisiae strains that originally were contaminants to the system and yet prevail in the industrial process. Here we present newly sequenced genomes (using Illumina short-read and PacBio long-read data) of two monosporic isolates (H3 and H4) of the S. cerevisiae PE-2, a predominant bioethanol strain in Brazil. The assembled genomes of H3 and H4, together with 42 draft genomes of sugarcane-fermenting (fuel ethanol plus cachaça) strains, were compared against those of the reference S288C and diverse S. cerevisiae. All genomes of bioethanol yeasts have amplified SNO2(3)/SNZ2(3) gene clusters for vitamin B1/B6 biosynthesis, and display ubiquitous presence of a particular family of SAM-dependent methyl transferases, rare in S. cerevisiae. Widespread amplifications of quinone oxidoreductases YCR102C/YLR460C/YNL134C, and the structural or punctual variations among aquaporins and components of the iron homeostasis system, likely represent adaptations to industrial fermentation. Interesting is the pervasive presence among the bioethanol/cachaça strains of a five-gene cluster (Region B) that is a known phylogenetic signature of European wine yeasts. Combining genomes of H3, H4, and 195 yeast strains, we comprehensively assessed whole-genome phylogeny of these taxa using an alignment-free approach. The 197-genome phylogeny substantiates that bioethanol yeasts are monophyletic and closely related to the cachaça and wine strains. Our results support the hypothesis that biofuel-producing yeasts in Brazil may have been co-opted from a pool of yeasts that were pre-adapted to alcoholic fermentation of sugarcane for the distillation of cachaça spirit, which historically is a much older industry than the large-scale fuel ethanol production.

Negative affect, affect regulation, and food choice: A value-based decision-making analysis

Introduction

Research has shown that negative affect leads to unhealthy eating, the top cause of death in the United States.

Objectives

This project examined whether AR (Affect Regulation) can be applied to incidental negative affect to improve eating behavior.

Methods

We conducted four studies.

Results

In Studies 1 and 2 (n=80), we developed a autobiographical negative affect induction, showed that it induces negative affect, and demonstrated that participants can learn to downregulate this negative affect. In Study 3 (n=40), participants completed a three-phase dietary food choice task. In phase 1, participants made food choices under neutral conditions. In phase 2, participants made food choices after receiving the negative affect induction from Studies 1 and 2. In phase 3, participants made food choices while downregulating the negative affect caused by the induction. In phase 2, participants placed less importance on health (b=-0.15, z=-5.99, p<.001) when making food choices than under neutral conditions (phase 1). In phase 3, participants successfully downregulated their negative affect (b=-1.2, t=-22.01, p<.001) and placed the same level of importance on health when making food choices as in phase 1, indicating that AR applied to incidental affect is an effective method for improving eating behavior. In Study 4 (n=120), we pre-registered and replicated our findings from Study 3. In addition, we fit drift-diffusion models to participants reaction time data and show that these results extent to the by-participant weights participants place on health when making food choices.

Conclusions

These results are a step towards scalable AR interventions to improve eating behavior.

Disclosure

No significant relationships.

Computer Retrieval of Mechanically - Indexed Articles

A program package offered by the Institute for Scientific Information, Philadelphia, for computer retrieval of machine-indexed scientific articles has been adapted for use on an IBM 360/30 system. Titles provided on magnetic tapes serve as input to the automatic retrieval programs; corresponding information from Current Contents is scanned manually for comparison.

Seven user interest profiles are matched against 45,000 titles, and the computer retrieval ratio is found to be 89% compared to 60% for manual search; computer relevance ratio is over 99%. The programs used are described and a simplified flow chart and a sample user profile are presented. Questions of computer running time and minimum configuration are considered, and reasons for non-retrieval are discussed. Future improvements being planned are indicated.

MEG sensor and source measures of visually induced gamma-band oscillations are highly reliable

High frequency brain oscillations are associated with numerous cognitive and behavioral processes. Non-invasive measurements using electro-/magnetoencephalography (EEG/MEG) have revealed that high frequency neural signals are heritable and manifest changes with age as well as in neuropsychiatric illnesses. Despite the extensive use of EEG/MEG-measured neural oscillations in basic and clinical research, studies demonstrating test-retest reliability of power and frequency measures of neural signals remain scarce. Here, we evaluated the test-retest reliability of visually induced gamma (30-100Hz) oscillations derived from sensor and source signals acquired over two MEG sessions. The study required participants (N=13) to detect the randomly occurring stimulus acceleration while viewing a moving concentric grating. Sensor and source MEG measures of gamma-band activity yielded comparably strong reliability (average intraclass correlation, ICC=0.861). Peak stimulus-induced gamma frequency (53-72Hz) yielded the highest measures of stability (ICCsensor=0.940; ICCsource=0.966) followed by spectral signal change (ICCsensor=0.890; ICCsource=0.893) and peak frequency bandwidth (ICCsensor=0.856; ICCsource=0.622). Furthermore, source-reconstruction significantly improved signal-to-noise for spectral amplitude of gamma activity compared to sensor estimates. Our assessments highlight that both sensor and source derived estimates of visually induced gamma-band oscillations from MEG signals are characterized by high test-retest reliability, with source derived oscillatory measures conferring an improvement in the stability of peak-frequency estimates. Importantly, our finding of high test-retest reliability supports the feasibility of pharma-MEG studies and longitudinal aging or clinical studies.