Towards a methodology for cluster searching to provide conceptual and contextual "richness" for systematic reviews of complex interventions: case study (CLUSTER)

Background Systematic review methodologies can be harnessed to help researchers to understand and explain how complex interventions may work. Typically, when reviewing complex interventions, a review team will seek to understand the theories that underpin an intervention and the specific context for that intervention. A single published report from a research project does not typically contain this required level of detail. A review team may find it more useful to examine a “study cluster”; a group of related papers that explore and explain various features of a single project and thus supply necessary detail relating to theory and/or context. We sought to conduct a preliminary investigation, from a single case study review, of techniques required to identify a cluster of related research reports, to document the yield from such methods, and to outline a systematic methodology for cluster searching. Methods In a systematic review of community engagement we identified a relevant project – the Gay Men’s Task Force. From a single “key pearl citation” we conducted a series of related searches to find contextually or theoretically proximate documents. We followed up Citations, traced Lead authors, identified Unpublished materials, searched Google Scholar, tracked Theories, undertook ancestry searching for Early examples and followed up Related projects (embodied in the CLUSTER mnemonic). Results Our structured, formalised procedure for cluster searching identified useful reports that are not typically identified from topic-based searches on bibliographic databases. Items previously rejected by an initial sift were subsequently found to inform our understanding of underpinning theory (for example Diffusion of Innovations Theory), context or both. Relevant material included book chapters, a Web-based process evaluation, and peer reviewed reports of projects sharing a common ancestry. We used these reports to understand the context for the intervention and to explore explanations for its relative lack of success. Additional data helped us to challenge simplistic assumptions on the homogeneity of the target population. Conclusions A single case study suggests the potential utility of cluster searching, particularly for reviews that depend on an understanding of context, e.g. realist synthesis. The methodology is transparent, explicit and reproducible. There is no reason to believe that cluster searching is not generalizable to other review topics. Further research should examine the contribution of the methodology beyond improved yield, to the final synthesis and interpretation, possibly by utilizing qualitative sensitivity analysis

Environmental-dependent proline accumulation in plants living on gypsum soils

[EN] Biosynthesis of proline¿or other compatible solutes¿is a conserved response of all organisms to different abiotic stress conditions leading to cellular dehydration. However, the biological relevance of this reaction for plant stress tolerance mechanisms remains largely unknown, since there are very few available data on proline levels in stress-tolerant plants under natural conditions. The aim of this work was to establish the relationship between proline levels and different environmental stress factors in plants living on gypsum soils. During the 2-year study (2009¿2010), soil parameters and climatic data were monitored, and proline contents were determined, in six successive samplings, in ten taxa present in selected experimental plots, three in a gypsum area and one in a semiarid zone, both located in the province of Valencia, in south-east Spain. Mean proline values varied significantly between species; however, seasonal variations within species were in many cases even wider, with the most extreme differences registered in Helianthemum syriacum (almost 30 lmol g-1 of DW in summer 2009, as compared to ca. 0.5 in spring, in one of the plots of the gypsum zone). Higher proline contents in plants were generally observed under lower soil humidity conditions, especially in the 2009 summer sampling preceded by a severe drought period. Our results clearly show a positive correlation between the degree of environmental stress and the proline level in most of the taxa included in this study, supporting a functional role of proline in stress tolerance mechanisms of plants adapted to gypsum. However, the main trigger of proline biosynthesis in this type of habitat, as in arid or semiarid zones, is water deficit, while the component of ¿salt stress¿ due to the presence of gypsum in the soil only plays a secondary role.This work has been supported by the Spanish Ministry of Science and Innovation (Project CGL2008-00438/BOS), with contribution from the European Regional Development Fund.Boscaiu, M.; Bautista Carrascosa, I.; Lidón Cerezuela, AL.; Llinares Palacios, JV.; Lull, C.; Donat-Torres, M.; Mayoral García-Berlanga, O.... (2013). Environmental-dependent proline accumulation in plants living on gypsum soils. Acta Physiologiae Plantarum. 35:2193-2204. https://doi.org/10.1007/s11738-013-1256-3S2193220435Alvarado JJ, Ruiz JM, López-Cantarero I, Molero J, Romero L (2000) Nitrogen metabolism in five plant species characteristic of gypsiferous soils. J Plant Physiol 156:612–616Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot 59:206–216Bates LS, Waldren RP, Teare ID (1973) Rapid determination of free proline for water stress studies. Plant Soil 39:205–207Briens M, Larher F (1982) Osmoregulation in halophytic higher plants: a comparative study of soluble carbohydrates, polyols, betaines and free proline. Plant, Cell Environ 5:287–292Burriel F, Hernando V (1947) Nuevo método para determinar el fósforo asimilable en los suelos. Anales de Edafología y Fisiología Vegetal 9:611–622Caballero I, Olano JM, Loidi J, Escudero A (2003) Seed bank structure along a semi-arid gypsum gradient in Central Spain. J Arid Environ 55:287–299Escudero A, Carnes LF, Pérez García F (1997) Seed germination of gypsophytes and gypsovags in semi-arid central Spain. J Arid Environ 36:487–497Escudero A, Somolinos RC, Olano JM, Rubio A (1999) Factors controlling the establishment of Helianthemum squamatum, an endemic gypsophite of semi-arid Spain. J Ecol 87:290–302FAO (1990) Management of gypsiferous soils. FAO Soils Bull 62Ferriol M, Pérez I, Merle H, Boira H (2006) Ecological germination requirements of the aggregate species Teucrium pumilum (Labiatae) endemic to Spain. Plant Soil 284:205–216Flowers TJ, Colmer TD (2008) Salinity tolerance in halophytes. New Phytol 179:945–963Flowers TJ, Troke PF, Yeo AR (1977) The mechanism of salt tolerance in halophytes. Ann Rev Plant Physiol 28:89–121Gil R, Lull C, Boscaiu M, Bautista I, Lidón A, Vicente O (2011) Soluble carbohydrates as osmolytes in several halophytes from a Mediterranean salt marsh. Not Bot Horti Agrobo 39(2):9–17Grigore MN, Boscaiu M, Vicente O (2011) Assessment of the relevance of osmolyte biosynthesis for salt tolerance of halophytes under natural conditions. Eur J Plant Sci Biotech 5:12–19Hare PD, Cress WA, Van Standen J (1998) Dissecting the roles of osmolyte accumulation during stress. Plant Cell Environ 21:535–553Keeney DR, Nelson DW (1982) Nitrogen inorganic forms. In: Page AL et al (eds) Methods of soil analysis, part 2: chemical and microbiological properties. Soil Science Society of America, Madison, pp 643–698Knudsen D, Peterson GA, Pratt PF (1982) Lithium, Sodium and Potassium. In: Page AL et al (eds) Methods of soil analysis, part 2: chemical and microbiological properties. Soil Science Society of America, Madison, pp 225–246Kuo S (1996) Phosphorus. In: Spark DL (ed) Methods of soil analysis: chemical methods, part 3. Soil Science Society of America, Madison, pp 869–919Martens H, Maes T (1989) Multivariate calibration. Wiley, New York, pp 97–108Martínez-Duro E, Ferrandis P, Escudero A, Luzuriaga AL, Herranz JM (2010) Secondary old-field succession in an ecosystem with restrictive soils: does time from abandonment matter? Appl Veg Sci 13:234–248Meyer SE (1986) The ecology of gypsophile endemism in the eastern Mojave desert. Ecology 67:1303–1313Meyer SE, García-Moya E (1989) Plant community patterns and soil moisture regime in gypsum grasslands of north central Mexico. J Arid Environ 16:147–155Meyer SE, García-Moya E, Lagunes-Espinoza LC (1992) Topographic and soil surface effects on gypsophile plant community patterns in central Mexico. J Veg Sci 3:429–438Moruno F, Soriano P, Vicente O, Boscaiu M, Estrelles E (2011) Opportunistic germination behaviour of Gypsophila (Caryophyllaceae) in two priority habitats from semi-arid Mediterranean steppes. Not Bot Horti Agrobo 39(1):18–23Mota JF, Sánchez Gómez P, Merlo Calvente ME, Catalán Rodríguez P, Laguna Lumbreras E, de la Cruz Rot M, Navarro Reyes FB, Marchal Gallardo F, Bartolomé Esteban C, Martínez Labarga JM, Sainz Ollero H, Valle Tendero F, Serra Laliga L, Martínez Hernández F, Garrido Becerra JA, Pérez García FJ (2009) Aproximación a la checklist de los gipsófitos ibéricos. Anales de Biología 31:71–80Murakeözy ÉP, Nagy Z, Duhazé C, Bouchereau A, Tuba Z (2003) Seasonal changes in the levels of compatible osmolytes in three halophytic species of inland saline vegetation in Hungary. J Plant Physiol 160:395–401Nelson DW, Sommers LE (1982) Total carbon, organic carbon, and organic matter. In: Page AL et al (eds) Methods of soil analysis, part 2: chemical and microbiological properties. Soil Science Society of America, Madison, pp 539–577Palacio S, Escudero A, Montserrat-Martí G, Maestro M, Milla R, Albert M (2007) Plants living on gypsum: beyond the specialist model. Ann Bot 99:333–343Parsons RF (1977) Gypsophily in plants—a review. Am Midl Nat 96:1–20Pueyo Y, Alados CL, Maestro M, Komac B (2007) Gypsophile vegetation patterns under a range of soil properties induced by topographical position. Plant Ecol 189:301–311Rivas-Martínez S, Rivas-Sáenz S (2009) Worldwide Bioclimatic Classification System. Phytosociological Research Center, Complutense University of Madrid, Spain. http://www.globalbioclimatics.org/ . Accessed 15 Nov 2012Romão RL, Escudero A (2005) Gypsum physical soil crusts and the existence of gypsophytes in semi-arid central Spain. Plant Ecol 181:127–137Rubio A, Escudero A (2000) Small-scale spatial soil-plant relationship in semi-arid gypsum environment. Plant Soil 220:139–150Ruíz JM, López-Cantarero I, Rivero RM, Romero L (2003) Sulphur phytoaccumulation in plant species characteristic of gypsiferous soils. Int J Phytorem 5:203–210Szabados L, Savouré A (2010) Proline: a multifunctional amino acid. Trends Plant Sci 15:89–97Szabados L, Kovács H, Zilberstein A, Bouchereau A (2011) Plants in extreme environments: importance of protective compounds in stress tolerance. Adv Bot Res 57:105–150Tecator Application Note (1984) AN 5226: Determination of ammonium in 2 M KCl soil extracts by FIAstar 5000. AN 5201: Determination of the sum of nitrate and nitrite in water by FIAstar 5000. (Adapted for 2 M KCl soil extracts)Tipirdamaz R, Gagneul D, Duhazé C, Aïnouche A, Monnier C, Özkum D, Larher F (2006) Clustering of halophytes from an inland salt marsh in Turkey according to their ability to accumulate sodium and nitrogenous osmolytes. Environ Exp Bot 57:139–153Verheye WH, Boyadgiev TG (1997) Evaluating the land use potential of gypsiferous soils from field pedogenic characteristics. Soil Use Manage 13:97–103Vicente O, Boscaiu M, Naranjo MA, Estrelles E, Bellés JM, Soriano P (2004) Responses to salt stress in the halophyte Plantago crassifolia (Plantaginaceae). J Arid Environ 58:463–481Yancey PH (2005) Organic osmolytes as compatible, metabolic and counteracting cytoprotectants in high osmolarity and other stresses. J Exp Biol 208:2819–283

Is salinity the main ecologic factor that shapes the distribution of two endemic Mediterranean plant species of the genus Gypsophila?

The final publication is available at Springer via http://dx.doi.org/10.1007/s11104-014-2218-2Aims Responses to salt stress of two Gypsophila species that share territory, but with different ecological optima and distribution ranges, were analysed. G. struthium is a regionally dominant Iberian endemic gypsophyte, whereas G. tomentosa is a narrow endemic reported as halophyte. Theworking hypothesis is that salt tolerance shapes the presence of these species in their specific habitats. Methods Taking a multidisciplinary approach, we assessed the soil characteristics and vegetation structure at the sampling site, seed germination and seedling development, growth and flowering, synthesis of proline and cation accumulation under artificial conditions of increasing salt stress and effect of PEG on germination and seedling development. Results Soil salinity was low at the all sampling points where the two species grow, but moisture was higher in the area of G. tomentosa. Differences were found in the species salt and drought tolerance. The different parameters tested did not show a clear pattern indicating the main role of salt tolerance in plant distribution. Conclusions G. tomentosa cannot be considered a true halophyte as previously reported because it is unable to complete its life cycle under salinity. The presence of G. tomentosa in habitats bordering salt marshes is a strategy to avoid plant competition and extreme water stressSoriano, P.; Moruno Manchón, JF.; Boscaiu Neagu, MT.; Vicente Meana, Ó.; Hurtado, A.; Llinares Palacios, JV.; Estrelles, E. (2014). Is salinity the main ecologic factor that shapes the distribution of two endemic Mediterranean plant species of the genus Gypsophila?. Plant and Soil. 384(1-2):363-379. doi:10.1007/s11104-014-2218-2S3633793841-2Alonso MA (1996) Flora y vegetación del Valle de Villena (Alicante). Instituto de Cultura Juan Gil-Albert, AlicanteAlvarado JJ, Ruiz JM, López-Cantarero I, Molero J, Romero L (2000) Nitrogen metabolism in five plant species characteristic of gypsiferous soils. Plant Physiol 156:612–616Ashraf M, Foolad MR (2007) Roles of glycine betaine and proline in improving plant abiotic stress resistance. Environ Exp Bot 59:206–216Ashraf MY (2009) Salt tolerance mechanisms in some halophytes from Saudi Arabia and Egypt. Res J Agric Biol Sci 5:191–206Bates LS, Waldren RP, Tear LD (1973) Rapid determination of free proline for water-stress studies. Plant Soil 39:205–207Ben-Gal A, Neori-Borochov H, Yermiyahu U, Shani U (2009) Is osmotic potential a more appropriate property than electrical conductivity for evaluating whole plant response to salinity? Environ Exp Bot 65:232–237Biondi E (2011) Phytosociology today: Methodological and conceptual evolution. Plant Biosyst 145:19–29Boscaiu M, Bautista I, Lidón A, Llinares J, Lull C, Donat P, Mayoral O, Vicente O (2013a) Environmental-dependent proline accumulation in plants living on gypsum soils. Acta Physiol Plant 35:2193–2204Boscaiu M, Llul C, Llinares J, Vicente O, Boira H (2013b) Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species. J Plant Ecol 6:177–186Bradford KJ (1990) A water relations analysis of seed germination rates. Plant Physiol 94:840–849Breckle SW (1999) Halophytic and gypsophytic vegetation of the Ebro-Basin at Los Monegros. In: Melic A, Blasco-Zumeta J (eds) Manifiesto científico por Los Monegros, vol 24, Bol. SEA., pp 101–104Brenchley JL, Probert RJ (1998) Seed germination responses to some environmental factors in the sea grass Zoostera capricorni from eastern Australia. Aquat Bot 62:177–188Cañadas EM, Ballesteros M, Valle F, Lorite J (2013) Does gypsum influence seed germination? Turk J Bot 38:141–147Chen Z, Cuin TA, Zhou M et al (2007) Compatible solute accumulation and stress-mitigating effects in barley genotypes contrasting in their salt tolerance. J Exp Bot 58:4245–4255Chutipaijit S, Cha-Um S, Sompornailin K (2009) Differential accumulation of proline and flavonoids in Indica rice varieties against salinity. Pak J Bot 41:2497–2506Cushman JC (2001) Osmoregulation in plants: implications for agriculture. Am Zool 41:758–769Debussche M, Thompson JD (2003) Habitat differentiation between two closely related Mediterranean plant species, the endemic Cyclamen balearicum and the widespread C. repandum. Acta Oecol 24:35–45Eskandari H, Kazemi K (2011) Germination and seedling properties of different wheat cultivars under salinity conditions. Not Sci Biol 3:130–134FAO (2006) Guidelines for soil descriptions, 5th edn. Food and Agricultural Organization of United Nation, RomeFerrandis P, Herranz JM, Copete MA (2005) Caracterización florística y edáfica de las estepas yesosas de Castilla-La Mancha. Invest Agrar Sist Recur For 14:195–216Flowers TJ, Hall JL (1978) Salt tolerance in Suaeda maritima (L.) Dum. The effect of sodium chloride on growth and soluble enzymes in a comparative study with Pisum sativum L. J Exp Bot 23:310–321Flowers TJ, Colmer TD (2008) Salinity tolerance in halophytes. New Phytol 179:945–963Flowers TJ, Hajibagheri MA, Clipson NJW (1986) Halophytes. Q Rev Biol 61:313–335García-Fuentes A, Salazar C, Torres JA, Cano E, Valle F (2001) Review of communities of Lygeum spartum L. in the south-eastern Iberian Peninsula (western Mediterranean). J Arid Environ 48:323–339Géhu JM (2006) Dictionnaire de Sociologie et Synécologie Végétales. J. Cramer, Berlin-Stuttgart, p 899Géhu JM (2011) On the opportunity to celebrate the centenary of modern phytosociology in 2010. Plant Biosyst 145(suppl):4–8Ghassemi F, Jakeman AJ, Nix HA (1995) Salinisation of land and water resources: human causes, extent, management and case studies. Canberra, Australia. CAB International, The Australian National University, WallingfordGrigore MN, Boscaiu M, Vicente O (2011) Assessment of the relevance of osmolyte biosynthesis for salt tolerance of halophytes under natural conditions. Eur J Plant Sci Biotech 5:12–19Grigore MN, Villanueva M, Boscaiu M, Vicente O (2012a) Do halophytes really require salts for their growth and development? An experimental approach mitigation of salt stress-induced inhibition of Plantago crassifolia reproductive development by supplemental calcium or magnesium. Not Sci Biol 4:23–29Grigore MN, Boscaiu M, Llinares J, Vicente O (2012b) Mitigation of salt stressed-induced Inhibition of Plantago crassifolia reproductive development by supplemental calcium or magnesium. Not Bot Horti Agrobo 40:58–66Hare PD, Cress WA (1997) Metabolic implications of stress-induced proline accumulation in plants. Plant Growth Regul 21:79–102Ishikawa SI, Kachi N (2000) Differential salt tolerance of two Artemisia species growing in contrasting coastal habitats. Ecol Res 15:241–247Kebreab E, Murdoch AJ (1999) Modelling the effects of water stress and temperature on germination rate of Orobanche aegyptiaca seeds. J Exp Bot 50:655–664Khan MA (2002) Halophyte seed germination: Success and Pitfalls. In: Hegazi AM, El-Shaer HM, El-Demerdashe S et al (eds) International symposium on optimum resource utilization in salt affected ecosystems in arid and semi arid regions. Desert Research Centre, Cairo, pp 346–358Khan MA, Gul B, Weber DJ (2000) Germination responses of Salicornia rubra to temperature and salinity. J Arid Environ 45:207–214Khan A, Rayner GD (2003) Robustness to non-normality of common tests for the many-sample location problem. J Appl Math Decis Sci 7:187–206Lidón A, Boscaiu M, Collado F, Vicente O (2009) Soil requirements of three salt tolerant, endemic species from south-east Spain. Not Bot Horti Agrobo 37:64–70López González G (1990) Gypsohila L. In: Castroviejo S, Laínz M, López G et al (eds) Flora Ibérica 2. Real Jardín Botánico, Madrid, pp 408–415Lutts S, Kinet JM, Bouharmont J (1996) Effects of salt stress on growth, mineral nutrition and proline accumulation in relation to osmotic adjustment in rice (Oryza sativa L.) cultivars differing in salinity resistance. Plant Growth Regul 19:207–218Madidi S, Baroudi B, Ameur FB (2004) Effects of salinity on germination and early growth of barley (Hordeum vulgare L.) cultivars. Int J Agric Biol 6:767–770Marchal FM, Lendínez ML, Salazar C, Torres JA (2008) Aportaciones al conocimiento de la vegetación gispsícola en el occidente de la provincia de Granada (sur de España). Lazaroa 29:95–100Médail F, Verlaque R (1997) Ecological characteristics and rarity of endemic plants from southern France and Corsica: implications for biodiversity conservation. Biol Conserv 80:269–281Meyer SE (1986) The ecology of gypsophile endemism in the Eastern Mojave desert. Ecology 67:1303–1313Moruno F, Soriano P, Oscar V, Boscaiu M, Estrelles E (2011) Opportunistic germination behaviour of Gypsophila (Caryophyllaceae) in two priority habitats from semi-arid Mediterranean steppes. Not Bot Horti Agrobo 9:18–23Mota JF, Sánchez Gómez P, Merlo Calvente ME, Catalán Rodríguez P, Laguna Lumbreras E, de la Cruz RM, Navarro Reyes FB, Marchal Gallardo F, Bartolomé Esteban C, Martínez Labarga JM, Sainz Ollero H, Valle Tendero F, Serra Laliga L, Martínez Hernández F, Garrido Becerra JA, Pérez García FJ (2009) Aproximación a la checklist de los gipsófitos ibéricos. An Biol 31:71–80Mota JF, Sola AJ, Jiménez-Sánchez ML, Pérez-García F, Merlo ME (2004) Gypsicolous flora, conservation and restoration of quarries in the southeast of the Iberian Peninsula. Biodivers Conserv 13:1797–1808Munns R (2002) Comparative physiology of salt and water stress. Plant Cell Environ 25:239–250Palacio S, Escudero A, Montserrat-Martí G, Maestro M, Milla R, Albert M (2007) Plants living on gypsum: beyond the specialist model. Ann Bot 99:333–343Peinado M, Martínez-Parras JM (1982) Sobre la posición fitosociológica de Gypsophila tomentosa L. Lazaroa 4:129–140Pueyo Y, Alados CL, Maestro M, Komac B (2007) Gypsophile vegetation patterns under a range of soil properties induced by topographical position. Plant Ecol 189:301–311Rasband WS (1997–2012) ImageJ. U S National Institutes of Health. http://rsb.info.nih.gov/ij/ , Bethesda, MarylandRivas-Martínez S (2005) Notions on dynamic-catenal phytosociology as a basis of landscape science. Plant Biosyst 139:135–144Rivas-Martínez S, Rivas-Saenz S (1996–2009) Worldwide bioclimatic classification system, Phytosociological Research Center, Spain. http://www.globalbioclimatics.org . Accessed 1 July 2013Rivas-Martínez S, Fernández-González F, Loidi J, Lousã M, Penas A (2001) Syntaxonomical checklist of vascular plant communities of Spain and Portugal to association level. Itinera Geobot 14:5–341Salmerón-Sánchez E, Martínez-Nieto MI, Martínez-Hernández F, Garrido-Becerra JA, Mendoza-Fernández AJ, Gil de Carrasco C, Ramos-Miras JJ, Lozano R, Merlo ME, Mota JF (2014) Ecology, genetic diversity and phylogeography of the Iberian endemic plant Jurinea pinnata (Lag.) DC. (Compositae) on two special edaphic substrates: dolomite and gypsum. Plant Soil 374:233–250Saradhi P, Alia P, Arora S, Prasad KV (1995) Proline accumulates in plants exposed to UV radiation and protects them against UV induced peroxidation. Biochem Biophys Res Commun 209:1–5Sekmen AH, Turkan I, Tanyolac ZO, Ozfidan C, Dinc A (2012) Different antioxidant defense responses to salt stress during germination and vegetative stages of endemic halophyte Gypsophila oblanceolata Bark. Environ Exp Bot 77:63–76Tipirdamaz R, Gagneul D, Duhaze C, Ainouche A, Monnier C, Ozkum D, Larher F (2006) Clustering of halophytes from an inland salt marsh in Turkey according to their ability to accumulate sodium and nitrogenous osmolytes. Environ Exp Bot 57:139–153Ungar IA (1996) Effect of salinity on seed germination, growth, and ion accumulation of Atriplex patula (Chenopodiaceae). Am J Bot 83:604–607USDA-ARS (2008) Research databases. Bibliography on salt tolerance. George E. Brown, Jr. Salinity Lab. US Dep. Agric., Agric. Res. Serv. Riverside, CA. http://www.ars.usda.gov/Services/docs.htm?docid=8908USSL Staff (1954) Diagnosis and improvement of saline and alkali soils. US Department of Agriculture Handbook no. 60, 160 ppVicente O, Boscaiu M, Naranjo M, Estrelles E, Bellés JM, Soriano P (2004) Responses to salt stress in the halophyte Plantago crassifolia (Plantaginaceae). J Arid Environ 58:463–48

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO

TESS Reveals a Short-period Sub-Neptune Sibling (HD 86226c) to a Known Long-period Giant Planet

The Transiting Exoplanet Survey Satellite mission was designed to find transiting planets around bright, nearby stars. Here, we present the detection and mass measurement of a small, short-period (≈4 days) transiting planet around the bright (V = 7.9), solar-type star HD 86226 (TOI-652, TIC 22221375), previously known to host a long-period (~1600 days) giant planet. HD 86226c (TOI-652.01) has a radius of 2.16 ± 0.08 R⊕ and a mass of ${7.25}_{-1.12}^{+1.19}$ M⊕, based on archival and new radial velocity data. We also update the parameters of the longer-period, not-known-to-transit planet, and find it to be less eccentric and less massive than previously reported. The density of the transiting planet is 3.97 g cm−3, which is low enough to suggest that the planet has at least a small volatile envelope, but the mass fractions of rock, iron, and water are not well-constrained. Given the host star brightness, planet period, and location of the planet near both the "radius gap" and the "hot Neptune desert," HD 86226c is an interesting candidate for transmission spectroscopy to further refine its composition

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres