915 research outputs found
Selection in parental species predicts hybrid evolution
AbstractWhile hybridization is recognized as important in evolution, its contribution to adaptation and diversification remains poorly understood. Using genomically diverged island populations of the homoploid hybrid Italian sparrow, we test predictions for phenotypic trait values and evolvability based on patterns of parental species divergence in four plumage color traits. We find associations between parental divergence and trait evolution in Italian sparrows. Fixed major QTL in species differences lead to hybrids with higher trait variation, and hence evolvability, than the parent species. Back and crown plumage show no correlation between current within-parent variability and among-parent differentiation. For these traits, Italian sparrow phenotypes are biased towards axes of high parental differentiation and show greater phenotypic novelty along axes of low current parental evolvability, as predicted when major QTL are involved in species differences. Crown color has consistently evolved back towards one parent, while back color varies among islands. We also find significant among-population diversification within the Italian sparrow. Hence, hybridization of the same parent species can generate different phenotypes. In conclusion, we find support for parental phenotypic divergence patterns reflecting divergence mechanisms, and hence such patterns can be useful in predicting how hybridization alters the potential to evolve and adapt.</jats:p
Multi-Sensor Field Studies of Lightning and Implications for MTG-LI
Future geostationary satellite systems will offer a variety of improved observing capabilities which will be
extremely useful for many applications like numerical weather forecasting, nowcasting of severe weather,
climate research or hydrology. The planning for MTG (Meteosat Third Generation) includes an optical
lightning imager (LI) as part of the payload. One requirement for a proper interpretation of these optical
data is a better understanding of what components of a flash are to be seen from space and how these
observations relate to ground based radio frequency observations. Therefore, the objectives of the present
study concern the improvement of the understanding of the complex lightning process which then enables
a proper interpretation of the optical data.
For assessing the future performances and benefits of a geostationary lightning sensor this study takes
advantage of the comprehensive lightning data sets obtained from the recent CHUVA field experiment
performed in Brazil. (CHUVA - Cloud processes of tHe main precipitation systems in Brazil: A contribUtion
to cloud resolVing modeling and to the GPM (GlobAl Precipitation Measurement)). During the rainy season
of 2011-2012 a large number of ground based lightning detection systems was set up in the Sao Paulo
area in Brazil. In the present study we look at the detailed radio frequency (RF) based observation from
LINET (Lightning detection network operated by DLR, nowcast and USP) and observing strokes in the
VLF/LF (very low and low frequency) range, the LMA (Lightning mapping array) from NASA observing RF
sources in the VHF (very high frequency) range and the TRMM-LIS (Tropical Rainfall Measuring
Mission-Lightning Imaging Sensor) optical space borne lightning imager. The LIS is used as a reference
instrument for the future MTG-LI sensor as well as for the corresponding GLM sensor (Geostationary
Lightning Mapper) on GOES-R. Thus it is possible to study the relations between the RF and optical
signals from lightning in detail and to assess the performance of the future geostationary observations from
a set of proxy satellite data generated from the ground based observations.
In confirmation of previous studies, it was found that often a direct temporal coincidence of RF
signals (LINET strokes) and optical pulses (LIS groups) exists. The short baseline configuration
of LINET allowed to observe the strokes mapping the flash branches similar to LMA, but by
locating the limited number of strong cloud strokes rather than a large number of weak source
points from leader steps. An initial breakdown phase of vertically propagating sources can often
be found in LINET and LMA data. The higher level LINET and LMA signals have higher
probability to be optically detected. Lower level LINET and LMA signals are optically detected
from above in case of missing high level precipitation as inferred from radar observations
provided by USP. The new comprehensive data set allows for constructing proxy data for the
future geostationary lightning mappers
"Palliative care is so much more than that” : a qualitative study exploring experiences of hospice staff and bereaved carers during the COVID-19 pandemic
Background: The way in which end-of-life care was provided changed significantly during the first 2 years of the COVID-19 pandemic. The national lockdown restrictions reduced formal care support services and increased the burden on many carers taking on the caring role for the first time. We aimed to explore decision-making about the place of care during the COVID-19 pandemic and the impact on experience from the perspectives of carers and hospice staff caring for people at the end-of-life.
Methods: A qualitative study using virtual interviews was conducted between October 2020 and April 2021. Data were analyzed thematically using framework analysis, an analytical framework that enables qualitative research to be organized into defined themes derived from the research question. Findings were presented to stakeholders in policy roundtables between March 2022 and March 2023 and discussed collaboratively with staff, stakeholders, and the public to inform policy and practice change.
Findings: A total of 37 participants (15 bereaved carers and 22 staff) were recruited via hospice services in England and Scotland. Four key themes were identified: (1) changing preferences relating to decision-making about the place of care and the impact at the time of death and into bereavement; (2) missed opportunities related to not being there, not having others around, and being robbed of memory-making; (3) the lone carer during a period of high intensity and reduced home support; (4) process vs. person-centered care resulting from changing rules and restrictions and prioritization of regulations over essential palliative care.
Conclusion: The study provides valuable global implications for all involved in end-of-life care. Despite great efforts to provide dignified, quality care, palliative care during the pandemic changed, focusing on essential ‘physical care'. The psychological suffering experienced by staff and carers may need longer-term support mechanisms put in place, which will benefit from a public health approach. Policymakers should consider improving carer identification and resources for wider end-of-life care education to support the needs of carers, health and social care staff, and citizens
Elliptic integral evaluations of Bessel moments
We record what is known about the closed forms for various Bessel function
moments arising in quantum field theory, condensed matter theory and other
parts of mathematical physics. More generally, we develop formulae for
integrals of products of six or fewer Bessel functions. In consequence, we are
able to discover and prove closed forms for with integers and , obtaining new results
for the even moments and . We also derive new closed forms
for the odd moments with and for with , relating the latter to Green functions on
hexagonal, diamond and cubic lattices. We conjecture the values of
, make substantial progress on the evaluation of ,
and and report more limited progress regarding
, and . In the process, we obtain 8
conjectural evaluations, each of which has been checked to 1200 decimal places.
One of these lies deep in 4- dimensional quantum field theory and two are
probably provable by delicate combinatorics. There remains a hard core of five
conjectures whose proofs would be most instructive, to mathematicians and
physicists alike.Comment: 51 pages, 1 Postscript figure, uses amsmath.sty, added reference
Habitat Association and Seasonality in a Mosaic and Bimodal Hybrid Zone between Chorthippus brunneus and C. jacobsi (Orthoptera: Acrididae)
Understanding why some hybrid zones are bimodal and others unimodal can aid in identifying barriers to gene exchange following secondary contact. The hybrid zone between the grasshoppers Chorthippus brunneus and C. jacobsi contains a mix of allopatric parental populations and inter-mingled bimodal and unimodal sympatric populations, and provides an ideal system to examine the roles of local selection and gene flow between populations in maintaining bimodality. However, it is first necessary to confirm, over a larger spatial scale, previously identified associations between population composition and season and habitat. Here we use cline-fitting of one morphological and one song trait along two valley transects, and intervening mountains, to confirm previously identified habitat associations (mountain versus valley) and seasonal changes in population composition. As expected from previous findings of studies on a smaller spatial scale, C. jacobsi dominated mountain habitats and mixed populations dominated valleys, and C. brunneus became more prevalent in August. Controlling for habitat and incorporating into the analysis seasonal changes in cline parameters and the standard errors of parental trait values revealed wider clines than previous studies (best estimates of 6.4 to 24.5 km in our study versus 2.8 to 4.7 km in previous studies) and increased percentage of trait variance explained (52.7% and 61.5% for transects 1 and 2 respectively, versus 17.6%). Revealing such strong and consistent patterns within a complex hybrid zone will allow more focused examination of the causes of variation in bimodality in mixed populations, in particular the roles of local selection versus habitat heterogeneity and gene flow between differentiated populations
The Sao Paulo Lightning Mapping Array (SPLMA): Prospects to GOES-R GLM and CHUVA
This paper presents the characteristics and prospects of a Lightning Mapping Array to be deployed at the city of S o Paulo (SPLMA). This LMA network will provide CHUVA campaign with total lightning, lightning channel mapping and detailed information on the locations of cloud charge regions for the thunderstorms investigated during one of its IOP. The real-time availability of LMA observations will also contribute to and support improved weather situational awareness and mission execution. For GOES-R program it will form the basis of generating unique and valuable proxy data sets for both GLM and ABI sensors in support of several on-going research investigation
Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China
A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak-feeding cynipid gallwasps are one of the best-studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom-up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant-associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae-associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores
Network structure and taxonomic composition of tritrophic communities of Fagaceae, cynipid gallwasps and parasitoids in Sichuan, China
A key question in insect community ecology is whether parasitoid assemblages are structured by the food plants of their herbivore hosts. Tritrophic communities centred on oak‐feeding cynipid gallwasps are one of the best‐studied tritrophic insect communities. Previous work suggests that host plant identity is a much stronger predictor of oak–cynipid interactions than of cynipid–parasitoid interactions. However, these relationships have not been formally quantified. We reason that the potential for ‘bottom‐up’ effects should increase with host plant phylogenetic diversity. We, therefore, generated quantified interaction network data for previously unstudied tritrophic cynipid communities in Sichuan, China, where, in addition to Quercus, cynipid host plants include Castanea, Castanopsis and Lithocarpus. We characterise these communities taxonomically and compare the extent to which host plant taxonomy predicts plant–herbivore and plant–parasitoid associations. We sampled 42,620 cynipid galls of 176 morphotypes from 23 host plant species, yielding over 4500 specimens of 64 parasitoid morphospecies. Many parasitoids were identifiable to chalcidoid taxa present in other Holarctic oak cynipid communities, with the addition of Cynipencyrtus (Cynipencyrtidae). As elsewhere, Sichuan parasitoid assemblages were dominated by generalists. Gallwasp–plant interaction networks were significantly more modular than parasitoid–plant association networks. Gallwasps were significantly more specialised to host plants (i.e. had higher mean d' values) than parasitoids. Parasitoid assemblages nevertheless showed significant plant‐associated beta diversity, with a dominant turnover component. We summarise parallels between our study and other Fagaceae‐associated cynipid communities and discuss our findings in light of the processes thought to structure tritrophic interactions centred on endophytic insect herbivores
Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases.
Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article
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