124 research outputs found
Reconstructing the effects of hurricanes over 155 years on the structure and diversity of trees in two tropical montane rainforests in Jamaica
Nutrient transporter expression in both the placenta and fetal liver are affected by maternal smoking
ACKNOWLEGDEMENTS Authors would like to thank the nurses of ward 309 (Aberdeen Royal Infirmary) for consenting participants and NHS Grampian Biorepository staff. Also, Gary Cameron for performing the LC-MS/MS cotinine analyses and Ms Linda Robertson for technical assistance. The authors state there are no conflicts of interest. Author contributions: NW, PF and PAF designed the research; NW conducted research, analysed data and wrote paper; PAF responsible for ethics (SAFeR study). All authors read and approved the final manuscript. Authors would like to thank the study funders: Glasgow Childrenâs Hospital Charity YRSS/PHD/2016/05 and UK Medical Research Council: MR/L010011/1, to PAF & PJOS and MR/P011535/1 to PAF. The funders played no role in the conduct, analysis or publication of the studyPeer reviewedPublisher PD
Prioritizing species, pathways, and sites to achieve conservation targets for biological invasion
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Endemic trees in a tropical biodiversity hotspot imperilled by an invasive tree
Non-native plants invade some tropical forests but there are few long-term studies of these invasions, and the consequences for plant richness and diversity are unclear. Repeated measurements of permanent plots in tropical montane rain forests in the Blue and John Crow Mountains National Park in Jamaica over 24 to 40 years coincided with invasion by a non-native tree, Pittosporum undulatum. By 2014, P. undulatum comprised, on average, 11.9% of stems â„ 3 cm diameter and 10.4% of the basal area across 16 widespread plots within c. 250 ha of the forests. Across these plots, the more P. undulatum increased in basal area over 24 years, the greater the decline in local, plot-scale tree species richness, and the greater the reduction in the percentage of stems of endemic tree species. Plot-scale tree diversity (Shannon and Fisher\u27s alpha) also declined the more P. undulatum basal area increased, but beta diversity across the plots was not reduced. Declines in local-scale tree species diversity and richness as the invasion progresses is especially concerning because Jamaica is a global biodiversity hotspot. Native birds disperse P. undulatum seeds widely, and future hurricanes will probably further increase its invasion by reducing canopy cover and therefore promoting growth rates of its established shade-tolerant seedlings. Remedial action is needed now to identify forest communities with greatest endemism, and to protect them through a continuing programme of control and removal of P. undulatum
Placental transporter localization and expression in the Human : the importance of species, sex, and gestational age differences
Grant Support: This work was supported by the Medical Research Council, UK (MR/L010011/1 to PAF, PJOS) and a Glasgow Children's Hospital Charity Research Fund and University of Aberdeen, UK, Elphinstone Scholarship to NW.Peer reviewedPublisher PD
Non-Native Plants Disrupt Dual Promotion of Native Alpha and Beta Diversity
Abstract Non-native species can alter patterns of species diversity at multiple spatial scales, but the processes that underlie multi-scale effects remain unclear. Here we show that non-native species reduce native diversity at multiple scales through simultaneous disruption of two processes of native community assembly: species immigration, which enhances alpha diversity, and community divergence, which enhances beta diversity. Community divergence refers to the process in which local communities diverge over time in species composition because the history of species immigration and, consequently, the way species affect one another within communities are variable among communities. Continuous experimental removal of species over four years of floodplain succession revealed that, when non-native species were excluded, stochastic variation in the timing of a dominant native species' arrival allowed local communities to diverge, thereby enhancing beta diversity, without compromising promotion of alpha diversity by species immigration. In contrast, when non-native species were allowed to enter experimental plots, they not only reduced native alpha diversity by limiting immigration, but also diminished the dominant native species' role in enhancing native beta diversity. Our results highlight the importance of community assembly and succession for understanding multi-scale effects of non-native species
Alterations in hypoglossal motor neurons due to GAD67 and VGAT deficiency in mice
There is an emerging body of evidence that glycinergic and GABAergic synaptic inputs onto motor neurons (MNs) help regulate the final number of MNs and axonal muscle innervation patterns. Using mutant glutamate decarboxylase 67 (GAD67) and vesicular inhibitory amino acid transporter (VGAT) deficient mice, we describe the effect that deficiencies of presynaptic GABAergic and/or glycinergic release have on the post-synaptic somato-dendritic structure of motor neurons, and the development of excitatory and inhibitory synaptic inputs to MNs. We use whole-cell patch clamp recording of synaptic currents in E18.5 hypoglossal MNs from brainstem slices, combined with dye-filling of these recorded cells with Neurobiotinâą, high-resolution confocal imaging and 3-dimensional reconstructions. Hypoglossal MNs from GAD67- and VGAT-deficient mice display decreased inhibitory neurotransmission and increased excitatory synaptic inputs. These changes are associated with increased dendritic arbor length, increased complexity of dendritic branching, and increased density of spiny processes. Our results show that presynaptic release of inhibitory amino acid neurotransmitters are potent regulators of hypoglossal MN morphology and key regulators of synaptic inputs during this critical developmental time point
Investigating Methodological Differences in the Assessment of Dendritic Morphology of Basolateral Amygdala Principal Neurons-A Comparison of Golgi-Cox and Neurobiotin Electroporation Techniques
Quantitative assessments of neuronal subtypes in numerous brain regions show large variations in dendritic arbor size. A critical experimental factor is the method used to visualize neurons. We chose to investigate quantitative differences in basolateral amygdala (BLA) principal neuron morphology using two of the most common visualization methods: Golgi-Cox staining and neurobiotin (NB) filling. We show in 8-week-old Wistar rats that NB-filling reveals significantly larger dendritic arbors and different spine densities, compared to Golgi-Cox-stained BLA neurons. Our results demonstrate important differences and provide methodological insights into quantitative disparities of BLA principal neuron morphology reported in the literature
Intraspecific trait variation can weaken interspecific trait correlations when assessing the whole-plant economic spectrum
The worldwide plant economic spectrum hypothesis predicts that leaf, stem, and root traits are correlated across vascular plant species because carbon gain depends on leaves being adequately supplied with water and nutrients, and because construction of each organ involves a trade-off between performance and persistence. Despite its logical and intuitive appeal, this hypothesis has received mixed empirical support. If traits within species diverge in their responses to an environmental gradient, then interspecific trait correlations could be weakened when measured in natural ecosystems. To test this prediction, we measured relative growth rates (RGR) and seven functional traits that have been shown to be related to fluxes of water, nutrients, and carbon across 56 functionally diverse tree species on (1) juveniles in a controlled environment, (2) juveniles in forest understories, and (3) mature trees in forests. Leaf, stem, and fine root traits of juveniles grown in a controlled environment were closely correlated with each other, and with RGR. Remarkably, the seven leaf, stem, and fine root tissue traits spanned a single dimension of variation when measured in the controlled environment. Forest-grown juveniles expressed lower leaf mass per area, but higher wood and fine root tissue density, than greenhouse-grown juveniles. Traits and growth rates were decoupled in forest-grown juveniles and mature trees. Our results indicate that constraints exist on the covariation, not just the variation, among vegetative plant organs; however, divergent responses of traits within species to environmental gradients can mask interspecific trait correlations in natural environments. Correlations among organs and relationships between traits and RGR were strong when plants were compared in a standardized environment. Our results may reconcile the discrepancies seen among studies, by showing that if traits and growth rates of species are compared across varied environments, then the interorgan trait correlations observed in controlled conditions can weaken or disappear
Alternative (backdoor) androgen production and masculinization in the human fetus
Funding: The study was supported by the following grants: Chief Scientist Office (Scottish Executive, CZG/4/742) (PAF and PJOS) (http://www.cso.scot.nhs.uk/funding-2/); NHS Grampian Endowments 08/02 (PAF and PJOS) and 15/1/010 (PAF, PF, US, and PJOS) (https://www.nhsgcharities.com/); the Glasgow Childrenâs Hospital Research Charity Research Fund, YRSS/PHD/2016/05 (NW, MB, PJOS, and PAF) (http://www.glasgowchildrenshospitalcharity.org/research/glasgow-childrens-hospital-charity-research-fund); the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement number 212885 (PAF) (https://ec.europa.eu/research/fp7/index_en.cfm); Medical Research Council Grants MR/L010011/1 (PAF and PJOS) and MR/K501335/1 (MB, PAF, and PJOS) (https://mrc.ukri.org/); and the Kronprinsessan Lovisas Foundation, âStiftelsen Gunvor och Josef AnĂ©rs,â the âStiftelsen Jane och Dan Olssons,â and the âStiftelsen Tornspiranâ (KS and OS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
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