296 research outputs found
Limited ecological opportunity influences the tempo of morphological evolution in birds
Funding Information: J.P.D., J.C., and H.M. received funding from the Hubert Curien Alliance (project 607280675 ). J.R. received funding from the Agence Nationale de la Recherche ( CEBA : ANR-10-LABX-25-01, TULIP : ANR-10-LABX-0041 , JCJC : ANR-23-CE02-0005-01 ). Collection of trait data was supported by Natural Environment Research Council ( NE/I028068/1 , NE/P004512/1 to J.A.T.). We thank Erandi Bonillas-Monge, Dan Nesbit, Christophe Patterson, Trevor Price, Francisco Henao Diaz, and several anonymous reviewers for helpful comments.Peer reviewe
Slowly but surely: gradual diversification and phenotypic evolution in the hyper-diverse tree fern family Cyatheaceae
Background and Aims
The tremendously unbalanced distribution of species richness across clades in the tree of life is often interpreted as the result of variation in the rates of diversification, which may themselves respond to trait evolution. Even though this is likely a widespread pattern, not all diverse groups of organisms exhibit heterogeneity in their dynamics of diversification. Testing and characterizing the processes driving the evolution of clades with steady rates of diversification over long periods of time are of importance in order to have a full understanding of the build-up of biodiversity through time.
Methods
We studied the macroevolutionary history of the species-rich tree fern family Cyatheaceae and inferred a time-calibrated phylogeny of the family including extinct and extant species using the recently developed fossilized birth–death method. We tested whether the high diversity of Cyatheaceae is the result of episodes of rapid diversification associated with phenotypic and ecological differentiation or driven by stable but low rates of diversification. We compared the rates of diversification across clades, modelled the evolution of body size and climatic preferences and tested for trait-dependent diversification.
Key Results
This ancient group diversified at a low and constant rate during its long evolutionary history. Morphological and climatic niche evolution were found to be overall highly conserved, although we detected several shifts in the rates of evolution of climatic preferences, linked to changes in elevation. The diversification of the family occurred gradually, within limited phenotypic and ecological boundaries, and yet resulted in a remarkable species richness.
Conclusions
Our study indicates that Cyatheaceae is a diverse clade which slowly accumulated morphological, ecological and taxonomic diversity over a long evolutionary period and provides a compelling example of the tropics as a museum of biodiversity
British Gynaecological Cancer Society recommendations and guidance on patient-initiated follow-up (PIFU)
The National Cancer Survivorship Initiative through the National Health Service (NHS) improvement in the UK started the implementation of stratified pathways of patient-initiated follow-up (PIFU) across various tumor types. Now the initiative is continued through the Living With and Beyond Cancer program by NHS England. Evidence from non-randomized studies and systematic reviews does not demonstrate a survival advantage to the long-established practice of hospital-based follow-up regimens, traditionally over 5 years. Evidence shows that patient needs are inadequately met under the traditional follow-up programs and there is therefore an urgent need to adapt pathways to the needs of patients. The assumption that hospital-based follow-up is able to detect cancer recurrences early and hence improve patient prognosis has not been validated. A recent survey demonstrates that follow-up practice across the UK varies widely, with telephone follow-up clinics, nurse-led clinics and PIFU becoming increasingly common. There are currently no completed randomized controlled trials in PIFU in gynecological malignancies, although there is a drive towards implementing PIFU. PIFU aims to individualize patient care, based on risk of recurrence and holistic needs, and optimizing resources. The British Gynaecological Cancer Society wishes to provide the gynecological oncology community with guidance and a recommendations statement regarding the value, indications, and limitations of PIFU in endometrial, cervical, ovarian, and vulvar cancers in an effort to standardize practice and improve patient care. [Abstract copyright: © IGCS and ESGO 2020. No commercial re-use. See rights and permissions. Published by BMJ.
Molecular ecology studies of species radiations: current research gaps, opportunities and challenges
Understanding the drivers and limits of species radiations is a crucial goal of evolutionary genetics and molecular ecology, yet research on this topic has been hampered by the notorious difficulty of connecting micro- and macroevolutionary approaches to studying the drivers of diversification. To chart the current research gaps, opportunities and challenges of molecular ecology approaches to studying radiations, we examine the literature in the journal Molecular Ecology and revisit recent high-profile examples of evolutionary genomic research on radiations. We find that available studies of radiations are highly unevenly distributed among taxa, with many ecologically important and species-rich organismal groups remaining severely understudied, including arthropods, plants and fungi. Most studies employed molecular methods suitable over either short or long evolutionary time scales, such as microsatellites or restriction site-associated DNA sequencing (RAD-seq) in the former case and conventional amplicon sequencing of organellar DNA in the latter. The potential of molecular ecology studies to address and resolve patterns and processes around the species level in radiating groups of taxa is currently limited primarily by sample size and a dearth of information on radiating nuclear genomes as opposed to organellar ones. Based on our literature survey and personal experience, we suggest possible ways forward in the coming years. We touch on the potential and current limitations of whole-genome sequencing (WGS) in studies of radiations. We suggest that WGS and targeted (‘capture’) resequencing emerge as the methods of choice for scaling up the sampling of populations, species and genomes, including currently understudied organismal groups and the genes or regulatory elements expected to matter most to species radiations
Effect of milk protein and whey permeate in large quantity lipid-based nutrient supplement on linear growth and body composition among stunted children: A randomized 2 × 2 factorial trial in Uganda
Background:
Despite possible benefits for growth, milk is costly to include in foods for undernourished children. Furthermore, the relative effects of different milk components, milk protein (MP), and whey permeate (WP) are unclear. We aimed to assess the effects of MP and WP in lipid-based nutrient supplement (LNS), and of LNS itself, on linear growth and body composition among stunted children.
Methods and findings:
We performed a randomized, double-blind, 2 × 2 factorial trial among 12 to 59 months old stunted children in Uganda. Children were randomized to 4 formulations of LNS with MP or soy protein isolate and WP or maltodextrin (100 g/day for 12 weeks) or no supplementation. Investigators and outcome assessors were blinded; however, participants were only blinded to the ingredients in LNS. Data were analyzed based on intention-to-treat (ITT) using linear mixed-effects models adjusted for age, sex, season, and site. Primary outcomes were change in height and knee-heel length, and secondary outcomes included body composition by bioimpedance analysis (ISRCTN13093195).
Between February and September 2020, we enrolled 750 children with a median age of 30 (interquartile range 23 to 41) months, with mean (± standard deviation) height-for-age z-score (HAZ) −3.02 ± 0.74 and 12.7% (95) were breastfed. The 750 children were randomized to LNS (n = 600) with or without MP (n = 299 versus n = 301) and WP (n = 301 versus n = 299), or no supplementation (n = 150); 736 (98.1%), evenly distributed between groups, completed 12-week follow-up. Eleven serious adverse events occurred in 10 (1.3%) children, mainly hospitalization with malaria and anemia, all deemed unrelated to the intervention.
Unsupplemented children had 0.06 (95% confidence interval, CI [0.02, 0.10]; p = 0.015) decline in HAZ, accompanied by 0.29 (95% CI [0.20, 0.39]; p < 0.001) kg/m2 increase in fat mass index (FMI), but 0.06 (95% CI [−0.002; 0.12]; p = 0.057) kg/m2 decline in fat-free mass index (FFMI).
There were no interactions between MP and WP. The main effects of MP were 0.03 (95% CI [−0.10, 0.16]; p = 0.662) cm in height and 0.2 (95% CI [−0.3, 0.7]; p = 0.389) mm in knee-heel length. The main effects of WP were −0.08 (95% CI [−0.21, 0.05]; p = 220) cm and −0.2 (95% CI [−0.7; 0.3]; p = 403) mm, respectively. Interactions were found between WP and breastfeeding with respect to linear growth (p < 0.02), due to positive effects among breastfed and negative effects among non-breastfed children.
Overall, LNS resulted in 0.56 (95% CI [0.42, 0.70]; p < 0.001) cm height increase, corresponding to 0.17 (95% CI [0.13, 0.21]; p < 0.001) HAZ increase, and 0.21 (95% CI [0.14, 0.28]; p < 0.001) kg weight increase, of which 76.5% (95% CI [61.9; 91.1]) was fat-free mass. Using height-adjusted indicators, LNS increased FFMI (0.07 kg/m2, 95% CI [0.0001; 0.13]; p = 0.049), but not FMI (0.01 kg/m2, 95% CI [−0.10, 0.12]; p = 0.800). Main limitations were lack of blinding of caregivers and short study duration.
Conclusions:
Adding dairy to LNS has no additional effects on linear growth or body composition in stunted children aged 12 to 59 months. However, supplementation with LNS, irrespective of milk, supports linear catch-up growth and accretion of fat-free mass, but not fat mass. If left untreated, children already on a stunting trajectory gain fat at the expense of fat-free mass, thus nutrition programs to treat such children should be considered
The role of Comprehension in Requirements and Implications for Use Case Descriptions
Within requirements engineering it is generally accepted that in writing specifications (or indeed any requirements phase document), one attempts to produce an artefact which will be simple to comprehend for the user. That is, whether the document is intended for customers to validate requirements, or engineers to understand what the design must deliver, comprehension is an important goal for the author. Indeed, advice on producing ‘readable’ or ‘understandable’ documents is often included in courses on requirements engineering. However, few researchers, particularly within the software engineering domain, have attempted either to define or to understand the nature of comprehension and it’s implications for guidance on the production of quality requirements.
Therefore, this paper examines thoroughly the nature of textual comprehension, drawing heavily from research in discourse process, and suggests some implications for requirements (and other) software documentation. In essence, we find that the guidance on writing requirements, often prevalent within software engineering, may be based upon assumptions which are an oversimplification of the nature of comprehension. Hence, the paper examines guidelines which have been proposed, in this case for use case descriptions, and the extent to which they agree with discourse process theory; before suggesting refinements to the guidelines which attempt to utilise lessons learned from our richer understanding of the underlying discourse process theory. For example, we suggest subtly different sets of writing guidelines for the different tasks of requirements, specification and design
Bringing traits back in the equation : A roadmap to understand species redistribution
Acknowledgments This research is a product of the BIOSHIFTS working group funded by the synthesis center (CESAB) of the French Foundation for Research on Biodiversity (FRB; www.fondationbiodiversite.fr) and the project FRAGSHIFTS funded by the Ministry of Ecological Transition (MTE), French Office for Biodiversity (OFB), and the French Foundation for Research on Biodiversity (FRB). We thank Holly Embke and two reviewers (including Tom Luhring) for their time and constructive comments that have improved the initial submission.Peer reviewe
British Gynaecological Cancer Society Recommendations for Evidence Based, Population Data Derived Quality Performance Indicators for Ovarian Cancer
Ovarian cancer survival in the UK lags behind comparable countries. Results from the ongoing National Ovarian Cancer Audit feasibility pilot (OCAFP) show that approximately 1 in 4 women with advanced ovarian cancer (Stage 2, 3, 4 and unstaged cancer) do not receive any anticancer treatment and only 51% in England receive international standard of care treatment, i.e., the combination of surgery and chemotherapy. The audit has also demonstrated wide variation in the percentage of women receiving anticancer treatment for advanced ovarian cancer, be it surgery or chemotherapy across the 19 geographical regions for organisation of cancer delivery (Cancer Alliances). Receipt of treatment also correlates with survival: 5 year Cancer survival varies from 28.6% to 49.6% across England. Here, we take a systems wide approach encompassing both diagnostic pathways and cancer treatment, derived from the whole cohort of women with ovarian cancer to set out recommendations and quality performance indicators (QPI). A multidisciplinary panel established by the British Gynaecological Cancer Society carefully identified QPI against criteria: metrics selected were those easily evaluable nationally using routinely available data and where there was a clear evidence base to support interventions. These QPI will be valuable to other taxpayer funded systems with national data collection mechanisms and are to our knowledge the only population level data derived standards in ovarian cancer. We also identify interventions for Best practice and Research recommendations
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