91 research outputs found
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The vulnerabilities of agricultural land and food production to future water scarcity
Rapidly increasing populations coupled with increased food demand requires either an expansion of agriculturalland or sufficient production gains from current resources. However, in a changing world, reduced wateravailability might undermine improvements in crop and grass productivity and may disproportionately affectdifferent parts of the world. Using multi-model studies, the potential trends, risks and uncertainties to land useand land availability that may arise from reductions in water availability are examined here. In addition, theimpacts of different policy interventions on pressures from emerging risks are examined.Results indicate that globally, approximately 11% and 10% of current crop- and grass-lands could be vul-nerable to reduction in water availability and may lose some productive capacity, with Africa and the MiddleEast, China, Europe and Asia particularly at risk. While uncertainties remain, reduction in agricultural land areaassociated with dietary changes (reduction of food waste and decreased meat consumption) offers the greatestbuffer against land loss and food insecurity
GW190814: gravitational waves from the coalescence of a 23 solar mass black hole with a 2.6 solar mass compact object
We report the observation of a compact binary coalescence involving a 22.2–24.3 Me black hole and a compact object with a mass of 2.50–2.67 Me (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO’s and Virgo’s third observing run on 2019 August 14 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of - + 241 45
41 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with gravitational waves, - + 0.112 0.009 0.008, and its secondary component is either the lightest black hole or the heaviest neutron star ever discovered in a double compact-object system. The
dimensionless spin of the primary black hole is tightly constrained to �0.07. Tests of general relativity reveal no measurable deviations from the theory, and its prediction of higher-multipole emission is confirmed at high confidence. We estimate a merger rate density of 1–23 Gpc−3 yr−1 for the new class of binary coalescence sources
that GW190814 represents. Astrophysical models predict that binaries with mass ratios similar to this event can form through several channels, but are unlikely to have formed in globular clusters. However, the combination of mass ratio, component masses, and the inferred merger rate for this event challenges all current models of the formation and mass distribution of compact-object binaries
Unravelling complexities involved in parenting a child with cystic fibrosis: an interpretative phenomenological analysis
We conducted a qualitative study with caregivers for a contemporary understanding of the challenge of caring for a child with cystic fibrosis (CF). A single case is presented that details one woman’s experience from her unique perspective of both, ‘mother to a child with CF’ and ‘CF healthcare provider’ using an interpretative phenomenological analysis. Emergent themes include: ‘trying to keep things normal,’ which includes different types of normality and routine management of treatment; ‘when things become difficult,’ which includes dealing with symptoms and battling with CF related decline; and, ‘the complexity of decision making.’ The discussion section expands on how, for this mother contrasting modes of managing CF (everyday life/full-on alert) co-existed and were further complicated by (i) role discrepancies (mother/nurse), and (ii) a dialectic between affect and reason. The CF parenting challenge increasingly involves responsibility for complex healthcare interventions and this study suggests a need for further enquiry into how caregivers are involved in the treatment plan and decision-making about treatment. Practice implications are proposed
Pine savanna overstorey influences on ground‐cover biodiversity
Question: Does the overstorey of pine savannas influence plant species biodiversity in the ground cover? Location: Camp Whispering Pines (30°41\u27 N; 90°29\u27 W), eastern Louisiana (USA). Methods: We used ecologically sensitive restoration logging to remove patches of Pinus palustris (longleaf pine) in a second-growth loess plain Pinus palustris savanna managed using frequent lightning season fires. Five years later, we measured numbers of vascular plant species and transmitted light in replicated 100-m2 plots. Treatments involved three different overstorey conditions: no overstorey for 5 years, no overstorey for several decades, and overstorey pines present for decades. Results: Both recent and long-term openings contained, on average, about 100 vascular plant species per 100 m2, 20% more than in similar-sized areas beneath overstorey trees. Responses varied with life form; more herbaceous species occurred in recent and older overstorey openings than beneath overstorey trees. Total numbers of all species and of less abundant forb species were positively and linearly related to light transmitted to ground level. Those species responding to openings in the overstorey and positively associated with increased transmitted light levels were monocarpic and short-lived perennial forb and grass species with a seed bank in the soil. In addition, community structure, as reflected in species composition and abundances, appeared to vary with canopy condition. Conclusions: Restoration involving ecologically sensitive removal of patches of overstorey pines in frequently burned pine savannas should benefit the ground cover and increase plant species biodiversity as a result of increased abundance of seed bank species. © IAVS; Opulus Press
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