Exposing the error hidden in plain sight: A critique of Calder's (1983) group selectionist seed-dispersal hypothesis for mistletoe "mimicry" of host plants

Some mistletoe species (Loranthaceae) resemble their host plants to a striking degree. Various mechanisms have been proposed for the developmental origins of novel traits that cause mistletoes to appear similar to their hosts, as well as for the adaptive phenotypic evolution of such traits. Calder (1983) proposed a logically flawed group selectionist seed-dispersal hypothesis for mistletoes to resemble their hosts. Calder's (1983) hypothesis does not provide a viable potential explanation for mistletoe resemblance to hosts.

82 THE IMPACT OF THE COVID-19 PANDEMIC ON THE ACTIVITY OF A RAPID-ACCESS GERIATRIC DAY HOSPITAL SERVICE

Background

In the 1970s, Jack Flanagan developed the first Geriatric Day Hospital (GDH) in Ireland. Since, the GDH model of care has evolved to accommodate for the growing demands of our ageing population. Before the COVID-19 pandemic, the operational scope of our GDH was extended to allow for the rapid medical and multidisciplinary assessment and follow-up of older patients. During the pandemic, the GDH did not suspend operations and remained open as a COVID-negative ambulatory pathway. We evaluated the activity of this GDH service.

Methods

Retrospective Service Evaluation Approval was granted by our Research & Innovation Office (Reference: 7419). Pseudonymised data corresponding to all GDH attendances between January 2017 and December 2021 were retrieved from the hospital electronic records. Yearly trends in proportions were tested with the Chi-square for trend statistic. Trends in monthly attendances were assessed via Statistical Process Control (SPC) charts with three-sigma limits. Statistical significance was set at p<0.05.

Results

There were 27,278 attendances of patients aged 65 and over to the GDH over the 5-year period (6,362, 5,978, 6,115, 4,306, and 4,517, respectively). Mean age was 82 every year. Of the 7,813 new episodes, yearly proportions referred directly by primary care teams were 10.4%, 29.5%, 38.6%, 24.5%, and 16.3% (p<0.001). SPC charts showed that Apr-May 2020 and Jan-Feb 2021 had significantly lower numbers of review attendances (50-59 and 146-142, respectively, average 324 p/m). However, new appointments did not significantly decline (average 130 p/m). Of the 7,813 new episodes, 2,595 (33.2%) were seen by Physiotherapy, and 1,860 (23.8%) by Occupational Therapy.

Conclusion

Our GDH saw a sustained number of new attendances and demonstrated increased community availability during the unprecedented COVID-19 crisis, especially during the first wave of the pandemic when hospital access was most affected. A rapid access GDH model can facilitate integrated care at times of crisis to promote ageing in place.

A genome resource for Acacia, Australia's largest plant genus

Acacia (Leguminosae, Caesalpinioideae, mimosoid clade) is the largest and most widespread genus of plants in the Australian flora, occupying and dominating a diverse range of environments, with an equally diverse range of forms. For a genus of its size and importance, Acacia currently has surprisingly few genomic resources. Acacia pycnantha, the golden wattle, is a woody shrub or tree occurring in south-eastern Australia and is the country's floral emblem. To assemble a genome for A. pycnantha, we generated long-read sequences using Oxford Nanopore Technology, 10x Genomics Chromium linked reads, and short-read Illumina sequences, and produced an assembly spanning 814 Mb, with a scaffold N50 of 2.8 Mb, and 98.3% of complete Embryophyta BUSCOs. Genome annotation predicted 47,624 protein-coding genes, with 62.3% of the genome predicted to comprise transposable elements. Evolutionary analyses indicated a shared genome duplication event in the Caesalpinioideae, and conflict in the relationships between Cercis (subfamily Cercidoideae) and subfamilies Caesalpinioideae and Papilionoideae (pea-flowered legumes). Comparative genomics identified a suite of expanded and contracted gene families in A. pycnantha, and these were annotated with both GO terms and KEGG functional categories. One expanded gene family of particular interest is involved in flowering time and may be associated with the characteristic synchronous flowering of Acacia. This genome assembly and annotation will be a valuable resource for all studies involving Acacia, including the evolution, conservation, breeding, invasiveness, and physiology of the genus, and for comparative studies of legumes.

Anhedonia and anergia predict mortality in older Australians living in residential aged care

OBJECTIVES

Depression is common in older adults and is linked to morbidity and mortality. The aim of this study was to investigate whether specific symptoms of depression (dysphoria, anhedonia and anergia) predicted mortality in older Australian Aged Care residents.

METHODS

Eighty older adults (M = 83.16 ± 7.14) without cognitive impairment residing in 14 Residential Aged Care facilities located in Melbourne, Australia, completed the 15-item Geriatric Depression Scale-Short Form (GDS-15) and the Standardized Mini Mental State Examination. Residential Aged Care facilities provided the primary end-point of all-cause mortality at follow-up (M = 5.4 years ± 0.1).

RESULTS

Univariate Kaplan-Meier survival curves and Cox Proportional Hazards regression analyses were used to evaluate whether symptoms of depression predicted all-cause mortality, with known prognostic factors controlled. The results indicated that anhedonia (Hazard Ratio = 2.931 [95% CI 1.278-6.722], p = .011) and anergia (Hazard Ratio = 2.783 [95% CI 1.065-7.276], p = .037) were associated with almost a threefold increased risk of mortality in older adults living in RAC in adjusted analyses. Dysphoria did not predict mortality.

CONCLUSIONS

These findings advance understanding of the mortality risks of anhedonia and anergia in an understudied population. Symptoms of anhedonia and anergia should be targeted for screening in older adults living in Aged Care to increase the detection and potential for referral to treatment for depressive presentation.

Towards a Systems Biology Approach to Understanding the Lichen Symbiosis: Opportunities and Challenges of Implementing Network Modelling

Lichen associations, a classic model for successful and sustainable interactions between micro-organisms, have been studied for many years. However, there are significant gaps in our understanding about how the lichen symbiosis operates at the molecular level. This review addresses opportunities for expanding current knowledge on signalling and metabolic interplays in the lichen symbiosis using the tools and approaches of systems biology, particularly network modelling. The largely unexplored nature of symbiont recognition and metabolic interdependency in lichens could benefit from applying a holistic approach to understand underlying molecular mechanisms and processes. Together with ‘omics’ approaches, the application of signalling and metabolic network modelling could provide predictive means to gain insights into lichen signalling and metabolic pathways. First, we review the major signalling and recognition modalities in the lichen symbioses studied to date, and then describe how modelling signalling networks could enhance our understanding of symbiont recognition, particularly leveraging omics techniques. Next, we highlight the current state of knowledge on lichen metabolism. We also discuss metabolic network modelling as a tool to simulate flux distribution in lichen metabolic pathways and to analyse the co-dependence between symbionts. This is especially important given the growing number of lichen genomes now available and improved computational tools for reconstructing such models. We highlight the benefits and possible bottlenecks for implementing different types of network models as applied to the study of lichens.

Assessing the benefits and usefulness of Schwartz Centre rounds in second-year medical students using clinical educator-facilitated group work session: not just "a facilitated moan"!

BACKGROUND

An experiential curriculum exposing medical students to the clinic early has many benefits but comes with the emotional stress this environment engenders. Schwartz rounds (SR) are an effective means to combat emotional stress and increasingly used in UK and USA hospitals. Recent studies show that the SR format may also provide benefits for medical students. This study aimed to investigate whether the guidance of SR in second year medical students provides the same benefits as to healthcare professionals.

METHODS

SR assessment involved 83 s year MBChB students in facilitated groupwork sessions. Topics discussed were "change and resilience" and "duty of candour". Students completed a Likert Scale questionnaire evaluating outcomes proffered by the Point of Care Foundation in collaboration with the Schwartz Foundation, with freeform feedback.

RESULTS

There was an 86% completion rate with 25% providing written feedback. Participants were more likely to agree than disagree that SR were beneficial. SR effectiveness in enhancing students' working relationship awareness and skills was strongly correlated with understanding the purpose of, and engagement with, the SR (P < 0.001). Similarly, engagement with the SR was strongly correlated with self-reporting of enhanced patient-centredness (P < 0.001). Freeform feedback could be grouped into five themes that revolved around understanding of the SR and engagement with the process. Many positive comments regarded the SR as a forum not only to "learn experientially" but to so in a "safe environment". Many negative comments stemmed from students not seeing any benefits of engagement with the SR, in that sharing experiences was "unbeneficial", "empathy is inherent and not learnt", or that sharing emotional problems is simply "moaning".

CONCLUSION

SRs are an effective way of fostering empathy and understanding towards patients and colleagues. However, for the students to benefit fully from the SR it is necessary for them to engage and understand the process. Therefore, for the successful implementation of SR into pre-clinical medical education, it is important to help students realise that SR are not merely a "facilitated whinge".

Accumulation over evolutionary time as a major cause of biodiversity hotspots in conifers

Biodiversity hotspots are important for understanding how areas of high species richness form, but disentangling the processes that produce them is difficult. We combine geographical ranges, phylogenetic relationships and trait data for 606 conifer species in order to explore the mechanisms underlying richness hotspot formation. We identify eight richness hotspots that overlap known centres of plant endemism and diversity, and find that conifer richness hotspots occur in mountainous areas within broader regions of long-term climate stability. Conifer hotspots are not unique in their species composition, traits or phylogenetic structure; however, a large percentage of their species are not restricted to hotspots and they rarely show either a preponderance of new radiating lineages or old relictual lineages. We suggest that conifer hotspots have primarily formed as a result of lineages accumulating over evolutionary time scales in stable mountainous areas rather than through high origination, preferential retention of relictual lineages or radiation of species with unique traits, although such processes may contribute to nuanced differences among hotspots. Conifers suggest that a simple accumulation of regional diversity can generate high species richness without additional processes and that geography rather than biology may play a primary role in hotspot formation.

Confirming a beneficial effect of the six-minute walk test on exercise confidence in patients with heart failure

Background:

Low confidence to exercise is a barrier to engaging in exercise in heart failure patients. Participating in low to moderate intensity exercise, such as the six-minute walk test, may increase exercise confidence.

Aim:

To compare the effects of a six-minute walk test with an educational control condition on exercise confidence in heart failure patients.

Methods:

This was a prospective, quasi-experimental design whereby consecutive adult patients attending an out-patient heart failure clinic completed the Exercise Confidence Scale prior to and following involvement in the six-minute walk test or an educational control condition.

Results:

Using a matched pairs, mixed model design ( n=60; 87% male; Mage=58.87±13.16), we identified a significantly greater improvement in Total exercise confidence ( F(1,54)=4.63, p=0.036, partial η2=0.079) and Running confidence ( F(1,57)=4.21, p=0. 045, partial η2=0.069) following the six-minute walk test compared to the educational control condition. These benefits were also observed after adjustment for age, gender, functional class and depression.

Conclusion:

Heart failure patients who completed a six-minute walk test reported greater improvement in exercise confidence than those who read an educational booklet for 10 min. The findings suggest that the six-minute walk test may be used as a clinical tool to improve exercise confidence. Future research should test these results under randomized conditions and examine whether improvements in exercise confidence translate to greater engagement in exercise behavior.

An overview of extant conifer evolution from the perspective of the fossil record

PREMISE OF THE STUDY

Conifers are an important living seed plant lineage with an extensive fossil record spanning more than 300 million years. The group therefore provides an excellent opportunity to explore congruence and conflict between dated molecular phylogenies and the fossil record.

METHODS

We surveyed the current state of knowledge in conifer phylogenetics to present a new time-calibrated molecular tree that samples ~90% of extant species diversity. We compared phylogenetic relationships and estimated divergence ages in this new phylogeny with the paleobotanical record, focusing on clades that are species-rich and well known from fossils.

KEY RESULTS

Molecular topologies and estimated divergence ages largely agree with the fossil record in Cupressaceae, conflict with it in Araucariaceae, and are ambiguous in Pinaceae and Podocarpaceae. Molecular phylogenies provide insights into some fundamental questions in conifer evolution, such as the origin of their seed cones, but using them to reconstruct the evolutionary history of specific traits can be challenging.

CONCLUSIONS

Molecular phylogenies are useful for answering deep questions in conifer evolution if they depend on understanding relationships among extant lineages. Because of extinction, however, molecular datasets poorly sample diversity from periods much earlier than the Late Cretaceous. This fundamentally limits their utility for understanding deep patterns of character evolution and resolving the overall pattern of conifer phylogeny.

Generating DNA sequence data with limited resources for molecular biology: Lessons from a barcoding project in Indonesia

The advent of the DNA sequencing age has led to a revolution in biology. The rapid and cost-effective generation of high-quality sequence data has transformed many fields, including those focused on discovering species and surveying biodiversity, monitoring movement of biological materials, forensic biology, and disease diagnostics. There is a need to build capacity to generate useful sequence data in countries with limited historical access to laboratory resources, so that researchers can benefit from the advantages offered by these data. Commonly used molecular techniques such as DNA extraction, PCR, and DNA sequencing are within the reach of small laboratories in many countries, with the main obstacles to successful implementation being lack of funding and limited practical experience. Here we describe a successful approach that we developed to obtain DNA sequence data during a small DNA barcoding project in Indonesia.

Testicular seminoma: Are clinical features and treatment outcomes any different in India?

AIM

This study aims to identify clinical features, treatment outcomes, and prognostic factors for relapse and survival in patients with testicular seminoma.

MATERIALS AND METHODS

Retrospective analysis of all patients with pure seminoma treated at our center during over a decade (January 2005-December 2014) was carried out. Patient demographics, tumor characteristics, and treatment details and pattern of recurrence were recorded in a structured format, and disease-free survival and overall survival were calculated.

RESULTS

Sixty-three patients' case records were included in the analysis. Ten patients developed disease in the undescended testis. All patients underwent orchiectomy as the initial treatment procedure. Majority of the patients were Stage I (57.14%) followed by Stage II (39.6%). Among the patients with Stage I, 55.5% received adjuvant chemotherapy while 22.2% received adjuvant radiation and the rest opted for surveillance. The compliance for active surveillance was very poor. Among patients with Stage II disease, majority (80%) were treated with adjuvant chemotherapy and the rest with radiation. At a median follow-up of 49 months, there were four recurrences of which three were salvaged successfully, and one patient remained alive with disease. There were no disease-related deaths.

CONCLUSIONS

Testicular seminoma remains to be relatively low and majority of them presented with Stage I disease and single agent carboplatin appeared to be the preferred adjuvant treatment. Advanced disease patients were treated with etoposide and cisplatin/bleomycin, etoposide and cisplatin chemotherapy and the clinical outcome is comparable with the Western literature.

Empirical evidence of fixed and homeostatic patterns of polyploid advantage in a keystone grass exposed to drought and heat stress

A long-standing hypothesis in evolutionary biology is that polyploid plants have a fitness advantage over diploids in climatically variable or extreme habitats. Here we provide the first empirical evidence that polyploid advantage in these environments is caused by two distinct processes: homeostatic maintenance of reproductive output under elevated abiotic stress, and fixed differences in seed development. In an outdoor climate manipulation experiment using coastal to inland Australian populations of the perennial grass Themeda triandra Forssk., we found that total output of viable seed in drought- and heat-stressed tetraploid plants was over four times higher than in diploids, despite being equal under more favourable growing conditions. Tetraploids also consistently produced heavier seeds with longer hygroscopic awns, traits which increase propagule fitness in extreme environments. These differences add to fitness benefits associated with broader-scale local adaptation of inland T. triandra populations to drought stress. Our study provides evidence that nucleotypic effects of genome size and increased reproductive flexibility can jointly underlie polyploid advantage in plants in stressful environments, and argue that ploidy can be an important criterion for selecting plant populations for use in genetic rescue, restoration and revegetation projects, including in habitats affected by climate change.