Estonian Academy of Sciences

Here we report the Simons Genome Diversity Project data set: high quality genomes from 300 individuals from 142 diverse populations. These genomes include at least 5.8 million base pairs that are not present in the human reference genome. Our analysis reveals key features of the landscape of human genome variation, including that the rate of accumulation of mutations has accelerated by about 5% in non-Africans compared to Africans since divergence. We show that the ancestors of some pairs of present-day human populations were substantially separated by 100,000 years ago, well before the archaeologically attested onset of behavioural modernity. We also demonstrate that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans; instead, their modern human ancestry is consistent with coming from the same source as that of other non-Africans. Deep whole-genome sequencing of 300 individuals from 142 diverse populations provides insights into key population genetic parameters, shows that all modern human ancestry outside of Africa including in Australasians is consistent with descending from a single founding population, and suggests a higher rate of accumulation of mutations in non-Africans compared to Africans since divergence. Three international collaborations reporting in this issue of Nature describe 787 high-quality genomes from individuals from geographically diverse populations. David Reich and colleagues analysed whole-genome sequences of 300 individuals from 142 populations. Their findings include an accelerated estimated rate of accumulation of mutations in non-Africans compared to Africans since divergence, and that indigenous Australians, New Guineans and Andamanese do not derive substantial ancestry from an early dispersal of modern humans but from the same source as that of other non-Africans. Eske Willerlsev and colleagues obtained whole-genome data for 83 Aboriginal Australians and 25 Papuans from the New Guinea Highlands. They estimate that Aboriginal Australians and Papuans diverged from Eurasian populations 51,000–72,000 years ago, following a single out-of-Africa dispersal. Luca Pagani et al. report on a dataset of 483 high-coverage human genomes from 148 populations worldwide, including 379 new genomes from 125 populations. Their analyses support the model by which all non-African populations derive most of their genetic ancestry from a single recent migration out of Africa, although a Papuan contribution suggests a trace of an earlier human expansion.

We present an Aboriginal Australian genomic sequence obtained from a 100-year-old lock of hair donated by an Aboriginal man from southern Western Australia in the early 20th century. We detect no evidence of European admixture and estimate contamination levels to be below 0.5%. We show that Aboriginal Australians are descendants of an early human dispersal into eastern Asia, possibly 62,000 to 75,000 years ago. This dispersal is separate from the one that gave rise to modern Asians 25,000 to 38,000 years ago. We also find evidence of gene flow between populations of the two dispersal waves prior to the divergence of Native Americans from modern Asian ancestors. Our findings support the hypothesis that present-day Aboriginal Australians descend from the earliest humans to occupy Australia, likely representing one of the oldest continuous populations outside Africa.

High-throughput sequencing studies generate vast amounts of taxonomic data. Evolutionary ecological hypotheses of the recovered taxa and Species Hypotheses are difficult to test due to problems with alignments and the lack of a phylogenetic backbone. We propose an updated phylum- and class-level fungal classification accounting for monophyly and divergence time so that the main taxonomic ranks are more informative. Based on phylogenies and divergence time estimates, we adopt phylum rank to Aphelidiomycota, Basidiobolomycota, Calcarisporiellomycota, Glomeromycota, Entomophthoromycota, Entorrhizomycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota and Olpidiomycota. We accept nine subkingdoms to accommodate these 18 phyla. We consider the kingdom Nucleariae (phyla Nuclearida and Fonticulida) as a sister group to the Fungi. We also introduce a perl script and a newick-formatted classification backbone for assigning Species Hypotheses into a hierarchical taxonomic framework, using this or any other classification system. We provide an example of testing evolutionary ecological hypotheses based on a global soil fungal data set.

Water is the key resource limiting world agricultural production. Although an impressive number of research reports have been published on plant drought tolerance enhancement via genetic modifications during the last few years, progress has been slower than expected. We suggest a feasible alternative strategy by application of rhizospheric bacteria coevolved with plant roots in harsh environments over millions of years, and harboring adaptive traits improving plant fitness under biotic and abiotic stresses. We show the effect of bacterial priming on wheat drought stress tolerance enhancement, resulting in up to 78% greater plant biomass and five-fold higher survivorship under severe drought. We monitored emissions of seven stress-related volatiles from bacterially-primed drought-stressed wheat seedlings, and demonstrated that three of these volatiles are likely promising candidates for a rapid non-invasive technique to assess crop drought stress and its mitigation in early phases of stress development. We conclude that gauging stress by elicited volatiles provides an effectual platform for rapid screening of potent bacterial strains and that priming with isolates of rhizospheric bacteria from harsh environments is a promising, novel way to improve plant water use efficiency. These new advancements importantly contribute towards solving food security issues in changing climates.

Research Article| April 01, 1994 Bathymetric and isotopic evidence for a short-lived Late Ordovician glaciation in a greenhouse period P. J. Brenchley; P. J. Brenchley 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom Search for other works by this author on: GSW Google Scholar J. D. Marshall; J. D. Marshall 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom Search for other works by this author on: GSW Google Scholar G. A. F. Carden; G. A. F. Carden 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom Search for other works by this author on: GSW Google Scholar D. B. R. Robertson; D. B. R. Robertson 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom Search for other works by this author on: GSW Google Scholar D. G. F. Long; D. G. F. Long 2Department of Geology, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada Search for other works by this author on: GSW Google Scholar T. Meidla; T. Meidla 3Institute of Geology, Tartu University, Tartu, EE2400, Estonia Search for other works by this author on: GSW Google Scholar L. Hints; L. Hints 4Institute of Geology, Academy of Sciences, Tallinn, EE0105 Estonia Search for other works by this author on: GSW Google Scholar T. F. Anderson T. F. Anderson 5Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 Search for other works by this author on: GSW Google Scholar Author and Article Information P. J. Brenchley 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom J. D. Marshall 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom G. A. F. Carden 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom D. B. R. Robertson 1Department of Earth Sciences, University of Liverpool, Liverpool L69 3BX, United Kingdom D. G. F. Long 2Department of Geology, Laurentian University, Sudbury, Ontario, P3E 2C6, Canada T. Meidla 3Institute of Geology, Tartu University, Tartu, EE2400, Estonia L. Hints 4Institute of Geology, Academy of Sciences, Tallinn, EE0105 Estonia T. F. Anderson 5Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1994) 22 (4): 295–298. https://doi.org/10.1130/0091-7613(1994)022<0295:BAIEFA>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation P. J. Brenchley, J. D. Marshall, G. A. F. Carden, D. B. R. Robertson, D. G. F. Long, T. Meidla, L. Hints, T. F. Anderson; Bathymetric and isotopic evidence for a short-lived Late Ordovician glaciation in a greenhouse period. Geology 1994;; 22 (4): 295–298. doi: https://doi.org/10.1130/0091-7613(1994)022<0295:BAIEFA>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The end Ordovician glaciation is distinct among Phanerozoic glaciations in that CO2, levels were generally high, yet major continental ice sheets accumulated on the Gondwana supercontinent. New oxygen isotopic data indicate substantial changes in sea-water temperatures and ice volume coinciding with glacio-eustatic changes in sea level reflecting the growth and decay of the Gondwana ice cap. Major glaciation was apparently confined to the Hirnantian and was 0.5-1 m.y. long, rather than the 35 m.y. of earlier estimates. Carbon isotope values indicate significant changes in carbon cycling as the oceans changed from a state with warm saline bottom waters to a state with cold deep-water circulation and then back again. We believe that the changes in the carbon cycle effected a reduction in PCO2 levels in the oceans and atmosphere and thus promoted glaciation but were unable to sustain icehouse conditions in a greenhouse world. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Summary By means of meta‐analyses we determined how 70 traits related to plant anatomy, morphology, chemistry, physiology, growth and reproduction are affected by daily light integral ( DLI ; mol photons m −2 d −1 ). A large database including 500 experiments with 760 plant species enabled us to determine generalized dose–response curves. Many traits increase with DLI in a saturating fashion. Some showed a more than 10‐fold increase over the DLI range of 1–50 mol m −2 d −1 , such as the number of seeds produced per plant and the actual rate of photosynthesis. Strong decreases with DLI (up to three‐fold) were observed for leaf area ratio and leaf payback time. Plasticity differences among species groups were generally small compared with the overall responses to DLI . However, for a number of traits, including photosynthetic capacity and realized growth, we found woody and shade‐tolerant species to have lower plasticity. We further conclude that the direction and degree of trait changes adheres with responses to plant density and to vertical light gradients within plant canopies. This synthesis provides a strong quantitative basis for understanding plant acclimation to light, from molecular to whole plant responses, but also identifies the variables that currently form weak spots in our knowledge, such as respiration and reproductive characteristics.

By means of rotations around two axes inclined at zeros (magic angles) of the l = 2 and l = 4 Legendre polynomials, first-order and second-order N.M.R. broadening can be averaged away. Experiments with a double-rotor on the central (1/2 ↔ - 1/2) transition of sodium-23 in polycrystalline sodium oxalate illustrate the elimination of broadening due to second-order quadrupolar effects leading to a thirtyfold increase in resolution compared to magic-angle spinning.

It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.

Summary Extensive within‐canopy light gradients importantly affect the photosynthetic productivity of leaves in different canopy positions and lead to light‐dependent increases in foliage photosynthetic capacity per area ( A A ). However, the controls on A A variations by changes in underlying traits are poorly known. We constructed an unprecedented worldwide database including 831 within‐canopy gradients with standardized light estimates for 304 species belonging to major vascular plant functional types, and analyzed within‐canopy variations in 12 key foliage structural, chemical and physiological traits by quantitative separation of the contributions of different traits to photosynthetic acclimation. Although the light‐dependent increase in A A is surprisingly similar in different plant functional types, they differ fundamentally in the share of the controls on A A by constituent traits. Species with high rates of canopy development and leaf turnover, exhibiting highly dynamic light environments, actively change A A by nitrogen reallocation among and partitioning within leaves. By contrast, species with slow leaf turnover exhibit a passive A A acclimation response, primarily determined by the acclimation of leaf structure to growth light. This review emphasizes that different combinations of traits are responsible for within‐canopy photosynthetic acclimation in different plant functional types, and solves an old enigma of the role of mass‐ vs area‐based traits in vegetation acclimation. Contents Summary 973 I. Introduction 973 II. Defining the structural, chemical and partitioning controls on foliage photosynthetic potentials 974 III. Construction of a global database on within‐canopy variation in leaf structural, chemical and photosynthetic characteristics 976 IV. Methodology for analysis of within‐canopy leaf trait variation: concepts and standardizations 978 V. Global variation in leaf characteristics through the canopies 981 VI. Trait scaling with light, plasticity and quantitative limitations 982 VII. Conclusions: the economics spectrum for the within‐canopy plasticity 989 Acknowledgements 989 References 990

Transpiration and ozone uptake rates were measured simultaneously in sunflower leaves at different stomatal openings and various ozone concentrations. Ozone uptake rates were proportional to the ozone concentration up to 1500 nanoliters per liter. The leaf gas phase diffusion resistance (stomatal plus boundary layer) to water vapor was calculated and converted to the resistance to ozone multiplying it by the theoretical ratio of diffusion coefficients for water vapor and ozone in air (1.67). The ozone concentration in intercellular air spaces calculated from the ozone uptake rate and diffusion resistance to ozone scattered around zero. The ozone concentration in intercellular air spaces was measured directly by supplying ozone to the leaf from one side and measuring the equilibrium concentration above the other side, and it was found to be zero. The total leaf resistance to ozone was proportional to the gas phase resistance to water vapor with a coefficient of 1.68. It is concluded that ozone enters the leaf by diffusion through the stomata, and is rapidly decomposed in cell walls and plasmalemma.

1. A cornerstone concept of ecological immunology is that immune function, interacting with various aspects of individual health state, plays a central role in the life‐history trade‐offs between conflicting demands of survival and reproduction. In order to develop this research, more knowledge about the applicability and usefulness of different health state assays is needed. 2. Eleven, mostly hemato‐serological, health state indices are described and their suitability for sensing the condition of breeding Great Tits ( Parus major L.) in terms of measurement precision, constancy in time, diurnal variation, and sex‐ and site‐related differences, is examined. 3. Measurement errors for the plasma albumin content, residual body mass, heterophile/lymphocyte ratio and total plasma protein content were relatively small compared with the total variation, suggesting these indices to be most adequate for ecological research. Measurement precision was lowest for the heterophile count and ‘buffy coat’ layer height (relative amount of leucocytes in total blood volume). Buffy coat layer height correlated weakly ( r =0·21) with total leucocyte count estimated from blood smears and therefore appeared inappropriate for estimation of the leucocyte number. 4. Body mass (residual in respect to size) and intensity of Haemoproteus blood parasite infection were the least variable state indices during the nestling period (for both, the correlation between the values measured on the 8th and 15th days of the nestling period=0·71). Haematocrit, heterophile count and albumin/globulin ratio showed no individual constancy across the nestling period, while other traits revealed moderate but statistically significant correlations between 8th‐ and 15th‐day values. 5. Leucocyte (both lymphocyte and heterophile) counts were higher among females captured at night compared with those captured during the day. 6. Females had higher intensities of Haemoproteus infection, higher heterophile counts and higher heterophile/lymphocyte ratios than males. Contrary to published information, females had higher haematocrits than males. 7. Haematocrit values in both sexes, as well as total plasma protein and albumin concentrations in males, differed significantly between Great Tits breeding in urban habitat and rural woodlands, respectively.

• Ectomycorrhizal (ECM) fungi are widespread plant root symbionts in boreal forests, but information is lacking on the fine scale distribution of roots and fungi in substrate patches of different quality, including coarse woody debris (CWD). • Wood and soil cores were taken systematically both horizontally and vertically through decayed logs and underlying soil layers in a mixed forest. Root tips were counted and ECM fungi identified by morphotyping and sequencing. • The abundance of root tips and ECM fungi was highly variable on a 5-cm scale. Most species were replaced on a 50-cm scale. Detrended correspondence analysis demonstrated strong preference of resupinate thelephoroid and athelioid fungi and Sebacinaceae for CWD, whereas ascomycetes and euagarics appeared more frequently in mineral soil. Clavulicium delectabile was determined to be an ECM fungus for the first time. • ECM fungi occupy different niches and show variable distribution patterns. CWD plays an important role as a habitat both for roots and ECM fungi. We suggest sampling larger soil cores and selecting random root tips in future studies. Sequencing is a powerful tool in ECM community studies.

Data sharing is one of the cornerstones of modern science that enables large-scale analyses and reproducibility. We evaluated data availability in research articles across nine disciplines in Nature and Science magazines and recorded corresponding authors' concerns, requests and reasons for declining data sharing. Although data sharing has improved in the last decade and particularly in recent years, data availability and willingness to share data still differ greatly among disciplines. We observed that statements of data availability upon (reasonable) request are inefficient and should not be allowed by journals. To improve data sharing at the time of manuscript acceptance, researchers should be better motivated to release their data with real benefits such as recognition, or bonus points in grant and job applications. We recommend that data management costs should be covered by funding agencies; publicly available research data ought to be included in the evaluation of applications; and surveillance of data sharing should be enforced by both academic publishers and funders. These cross-discipline survey data are available from the plutoF repository.

Maximum Rubisco activities (V(cmax)), rates of photosynthetic electron transport (J(max)), and leaf nitrogen and chlorophyll concentrations were studied along a light gradient in the canopies of four temperate deciduous species differing in shade tolerance according to the ranking: Populus tremula L. < Fraxinus excelsior L. < Tilia cordata Mill. = Corylus avellana L. Long-term light environment at the canopy sampling locations was characterized by the fractional penetration of irradiance in the photosynthetically active spectral region (I(sum)). We used a process-based model to distinguish among photosynthesis limitations resulting from variability in fractional nitrogen investments in Rubisco (P(R)), bioenergetics (P(B), N in rate-limiting proteins of photosynthetic electron transport) and light harvesting machinery (P(L), N in chlorophyll and thylakoid chlorophyll-protein complexes). On an area basis, V(cmax) and J(max) (V(a) (cmax) and J(a) (max)) increased with increasing growth irradiance in all species, and the span of variation within species ranged from two (T. cordata) to ten times (C. avellana). Examination of mass-based V(cmax) and J(max) (V(m) (cmax) and J(m) (max)) demonstrated that the positive relationships between area-based quantities and relative irradiance mostly resulted from the scaling of leaf dry mass per area (M(A)) with irradiance. Although V(m) (cmax) and J(m) (max) were positively related to growth irradiance in C. avellana, and J(m) (max) was positively related to irradiance in P. tremula, the variation range was only a factor of two. Moreover, V(m) (cmax) and J(m) (max) were negatively correlated with relative irradiance in T. cordata. Rubisco activity in crude leaf extracts generally paralleled the gas-exchange data, but it was independent of light in T. cordata, suggesting that declining V(m) (cmax) with increasing relative irradiance was related to increasing diffusive resistances from the intercellular air spaces to the sites of carboxylation in this species. Because irradiance had little effect on foliar nitrogen concentration, the relationships of P(B) and P(R) with irradiance were similar to those of V(m) (cmax) and J(m) (max). Shade-intolerant species tended to have greater P(B) and P(R) and also larger V(a) (cmax) and J(a) (max) than more shade-tolerant species. However, for the whole material, P(B) and P(R) varied only about 50%, whereas V(a) (cmax) and J(a) (max) varied more than 15-fold, further emphasizing the importance of leaf anatomical plasticity in determining photosynthetic acclimation to high irradiance. Leaf chlorophyll concentrations and fractional nitrogen investments in light harvesting increased hyperbolically with decreasing irradiance to improve quantum use efficiency for incident irradiance. The effect of irradiance on P(L) was of the same order as its effect in the opposite direction on M(A), leading to either a constant model estimate of leaf absorptance with I(sum) or a slightly positive correlation. We conclude that leaf morphological plasticity is a more relevant determinant of foliage adaptation to high irradiance than foliage biochemical properties, whereas biochemical adaptation to low irradiance is of the same magnitude as the anatomical adjustments. Although shade-tolerant species did not have greater chlorophyll concentrations and P(L) than shade-intolerant species, they possessed lower M(A), and could maintain a more extensive foliar display for light capture with constant biomass investment in leaves.

Abstract The resonant secondary radiation spectrum of impurity centres in crystals is studied on the basis of a second‐order approximation for the interaction between the electromagnetic field and the material. It is shown that for the case of excitation in the phonon wing of the absorption band, the main part of the secondary radiation represents the ordinary luminescence. The spectrum also contains Rayleigh and Raman scattering which is considerably weaker (by about four orders of magnitude). Formulas are obtained for the intensities of Rayleigh‐ and Raman scattering; particular consideration is made for the case of large Stokes' losses. It is also shown that excitation in the region of the pure‐electronic line yields a spectrum consisting of the Rayleigh and the pure‐electronic line, and the phonon wing of the luminescence.

IMPORTANCE: Neuroticism is a pervasive risk factor for psychiatric conditions. It genetically overlaps with major depressive disorder (MDD) and is therefore an important phenotype for psychiatric genetics. The Genetics of Personality Consortium has created a resource for genome-wide association analyses of personality traits in more than 63,000 participants (including MDD cases). OBJECTIVES: To identify genetic variants associated with neuroticism by performing a meta-analysis of genome-wide association results based on 1000 Genomes imputation; to evaluate whether common genetic variants as assessed by single-nucleotide polymorphisms (SNPs) explain variation in neuroticism by estimating SNP-based heritability; and to examine whether SNPs that predict neuroticism also predict MDD. DESIGN, SETTING, AND PARTICIPANTS: Genome-wide association meta-analysis of 30 cohorts with genome-wide genotype, personality, and MDD data from the Genetics of Personality Consortium. The study included 63,661 participants from 29 discovery cohorts and 9786 participants from a replication cohort. Participants came from Europe, the United States, or Australia. Analyses were conducted between 2012 and 2014. MAIN OUTCOMES AND MEASURES: Neuroticism scores harmonized across all 29 discovery cohorts by item response theory analysis, and clinical MDD case-control status in 2 of the cohorts. RESULTS: A genome-wide significant SNP was found on 3p14 in MAGI1 (rs35855737; P = 9.26 × 10-9 in the discovery meta-analysis). This association was not replicated (P = .32), but the SNP was still genome-wide significant in the meta-analysis of all 30 cohorts (P = 2.38 × 10-8). Common genetic variants explain 15% of the variance in neuroticism. Polygenic scores based on the meta-analysis of neuroticism in 27 cohorts significantly predicted neuroticism (1.09 × 10-12 < P < .05) and MDD (4.02 × 10-9 < P < .05) in the 2 other cohorts. CONCLUSIONS AND RELEVANCE: This study identifies a novel locus for neuroticism. The variant is located in a known gene that has been associated with bipolar disorder and schizophrenia in previous studies. In addition, the study shows that neuroticism is influenced by many genetic variants of small effect that are either common or tagged by common variants. These genetic variants also influence MDD. Future studies should confirm the role of the MAGI1 locus for neuroticism and further investigate the association of MAGI1 and the polygenic association to a range of other psychiatric disorders that are phenotypically correlated with neuroticism.

Fossil pollen data supplemented by tree macrofossil records were used to reconstruct the vegetation of the Former Soviet Union and Mongolia at 6000 years. Pollen spectra were assigned to biomes using the plant‐functional‐type method developed by Prentice et al . (1996). Surface pollen data and a modern vegetation map provided a test of the method. This is the first time such a broad‐scale vegetation reconstruction for the greater part of northern Eurasia has been attempted with objective techniques. The new results confirm previous regional palaeoenvironmental studies of the mid‐Holocene while providing a comprehensive synopsis and firmer conclusions. West of the Ural Mountains temperate deciduous forest extended both northward and southward from its modern range. The northern limits of cool mixed and cool conifer forests were also further north than present. Taiga was reduced in European Russia, but was extended into Yakutia where now there is cold deciduous forest. The northern limit of taiga was extended (as shown by increased Picea pollen percentages, and by tree macrofossil records north of the present‐day forest limit) but tundra was still present in north‐eastern Siberia. The boundary between forest and steppe in the continental interior did not shift substantially, and dry conditions similar to present existed in western Mongolia and north of the Aral Sea.

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A theoretical analysis of the general excitation phenomena of half-integer $I&gt;\frac{1}{2}$ nuclear spins in a strong radio-frequency field shows that coherence between the affected spin states leads to complicated time behavior of the total nuclear magnetization. Very short excitation pulses lead to quantitatively useful high-resolution NMR spectra of quadrupolar nuclei in powder samples spun at the magic angle, while selective spin-state time development during longer rf pulses permits the use of two-dimensional Fourier-transform NMR techniques with simultaneous measurement of the isotropic chemical shifts and the corresponding quadrupole interaction parameters.

Leaf economics and hydraulic traits are critical to leaf photosynthesis, yet it is debated whether these two sets of traits vary in a fully coordinated manner or there is room for independent variation. Here, we tested the relationship between leaf economics traits, including leaf nitrogen concentration and leaf dry mass per area, and leaf hydraulic traits including stomatal density and vein density in five tropical-subtropical forests. Surprisingly, these two suites of traits were statistically decoupled. This decoupling suggests that independent trait dimensions exist within a leaf, with leaf economics dimension corresponding to light capture and tissue longevity, and the hydraulic dimension to water-use and leaf temperature maintenance. Clearly, leaf economics and hydraulic traits can vary independently, thus allowing for more possible plant trait combinations. Compared with a single trait dimension, multiple trait dimensions may better enable species adaptations to multifarious niche dimensions, promote diverse plant strategies and facilitate species coexistence.