bluuebunny/crossref_metadata_2025_split huggingface dataset:
A molecular phylogeny of the grass subfamily Panicoideae (Poaceae) shows multiple origins of C4 photosynthesis
Authors: Giussani Liliana M. , Cota‐Sánchez J. Hugo , Zuloaga Fernando O. , Kellogg Elizabeth A. 
Published: February 2007

DNA sequence data from the chloroplast gene ndhF were analyzed to estimate the phylogeny of the subfamily Panicoideae, with emphasis on the tribe Paniceae. Our data suggest that the subfamily is divided into three strongly supported clades, corresponding to groups with largely identical base chromosome numbers. Relationships among the three clades are unclear. In unweighted parsimony analyses, the two major clades with x = 10 (Andropogoneae and x = 10 Paniceae) are weakly supported as sister taxa. The third large clade corresponds to x = 9 Paniceae. In analyses under implied weight, the two clades of Paniceae are sisters, making the tribe monophyletic. Neither resolution is strongly supported.Our molecular phylogenies are not congruent with previous classifications of tribes or subtribes. Based on this sample of species, we infer that C4 photosynthesis has evolved independently several times, although a single origin with multiple reversals and several reacquisitions is only slightly less parsimonious. The phosphoenol pyruvate carboxykinase (PCK) subtype of C4 photosynthesis has evolved only once, as has the NAD‐malic enzyme (ME) subtype; all other origins are NADP‐ME. Inflorescence bristles are apparently homologous in the genera Setaria and Pennisetum, contrary to opinions of most previous authors. Some genera, such as Digitaria, Echinochloa, and Homolepis are supported as monophyletic. The large genus Paspalum is shown to be paraphyletic, with Thrasya derived from within it. As expected, Panicum is polyphyletic, with lineages derived from multiple ancestors across the tree. Panicum subg. Panicum is monophyletic. Panicum subg. Dichanthelium, subg. Agrostoides, and subg. Phanopyrum are unrelated to each other, and none is monophyletic. Only Panicum subg. Dichanthelium sect. Dichanthelium, represented by P. sabulorum and P. koolauense, is monophyletic. Panicum subg. Megathyrsus, a monotypic subgenus including only the species P. maximum, is better placed in Urochloa, as suggested by other authors.
TheScilla plumbeapuzzle—present status of the genusScillasensu lato in southern Africa and description ofSpetaea lachenaliiflora, a new genus and species of Massonieae (Hyacinthaceae)
Authors: Wetschnig Wolfgang , Pfosser Martin 
Published: February 2007

AbstractWe have studied a taxon from South Africa that has been hidden for more than 150 years withinScilla plumbea(Hyacinthaceae). However, phylogenetic reconstruction based ontrnL-Fdata, morphological evidence (including seed characters), and karyology suggest independent status. DNA data place it close to theDaubenyaalliance but not close to any particular genus of Massonieae previously included withinScillas.l. Unique characters of seeds indicate that this taxon does not belong to theDaubenyaclade. Analysis of the iconotype ofScilla plumbeaLindl., on the other hand, reveals morphological details suggesting membership in theScilla natalensisclade (= genusMerwillain the recent classification of Speta).Merwilla, however, occupies a basal position among Massonieae and is not related to theDaubenyaclade. Based on all data, we describe this taxon as a new genus and speciesSpetaea lachenaliifloraWetschnig & Pfosser.
How many species of seed plants are there?
Authors: Scotland Robert W. , Wortley Alexandra H. 
Published: February 2007

AbstractRecent estimates of the number of described species of seed plant have varied by as much as 62%. The underlying methodology of these estimates is characterised and discussed. We present a revised figure for the number of seed plants based on estimating rates of synonymy in a sample of recently monographed taxa. We conclude that some recent figures overestimate the number of described seed plant species by more than 200,000. This discrepancy is explained by an over­reliance on checklists and floristic studies that underestimate synonymy rates.
The systematic status of Plagiochila sects. Bidentes Carl and Caducilobae Inoue (Hepaticae) inferred from nrDNA ITS sequences
Authors: Groth Henk , Helms Gert , Heinrichs Jochen 
Published: February 2007

AbstractPlagiochila section Bidentes Carl was erected for some of the tiniest species of the genus that often possess caducous or fragmenting leaves. Current discussions focus on whether P. sect. Bidentes represents a natural species group or should be broken up into two lineages, P. sect. Bidentes s.str. and P. sect. Caducilobae Inoue. Phylogenetic analyses of nrITS sequences of 28 species of Plagiochila produced several independent lineages that correspond with morphologically and phytochemically defined sections of Plagiochila (i.e., P. sects. Arrectae, Fuscoluteae, Glaucescentes, Hylacoetes, Plagiochila, Rutilantes, and Vagae). Plagiochila bidens, the type of P. sect. Bidentes, is placed in a clade with several members of P. sect. Arrectae Carl; therefore, P. sect. Bidentes is treated as a synonym of P. sect. Arrectae. The type of P. sect. Caducilobae, P. caduciloba H.L. Blomq., as well as several other members of the “Bidentes/Caducilobae‐complex”, cluster with members of P. sect. Rutilantes Carl, a group to which can therefore be assigned the majority of species currently placed in P. sect. Bidentes, i.e., excluding the type. Morphologically, members of P. sect. Rutilantes are characterized by a “free” perianth. In contrast, the members of P. sect. Arrectae usually possess perianths that are covered by bracts at least in the basal half. Plagiochila loriloba Herzog ex Carl [syn.: P. cuneata var. loriloba (Herzog ex Carl) Herzog] is recognized at the rank of species.
nrDNA ITS sequences and affinities (Umbelliferae) of Sino‐Himalayan Apioideae
Authors: Valiejo-Roman Carmen M. , Terentieva Elena I. , Samigullin Tagir H. , Pimenov Michael G. 
Published: February 2007

AbstractThe internal transcribed spacers (ITS1 and ITS2) of 18S‐26S nuclear ribosomal DNA were sequenced for 13 species of Apioideae from the Sino‐Himalayan flora [Apium ventricosum(=Sium frigidum),Arcuatopterus thalictrioideus, Cyclorhiza peucedanifolia, Meeboldia achilleifolia, Notopterygium forbesii, N. weberbauerianum, Pternopetalum delavayi, P. vulgare, Pterocyclus rivulorum, Sinocarum cruciatum, Sinodielsia delavayi, Tongoloa elata, andTrachydium simplicifolium], relationships of which are controversial or obscure and unresolved on the basis of morphological data. Phylogenetic trees inferred by neighbor‐joining, parsimony analysis, and Bayesian inference are topologically congruent, but not identical. The newly obtained data permit testing of several hypotheses regarding these taxa. Some of the early hypotheses treat local species under well‐known European genera (e.g.,Apium, Carum, Pimpinella, etc.), but these are not supported by phylogenetic analysis of nuclear rDNA spacer sequences. In particular,Sinodielsia, Meeboldia, Tongoloa, andPternopetalumare distant fromPimpinella; Pternopetalum, SinocarumandTongoloaare remote fromCarum; Arcuatopterusis separate fromPeucedanumandAngelica;Pternopetalumis distinct fromCryptotaenia; andNotopterygiumandPterocyclusare separate fromPleurospermum. ChineseNotopterygiumis shown to be closely related to Siberian and MongolianHansenia; this, plus similarity in fruit structure, suggests that they are congeneric.Apium ventricosum, more commonly known as Sium frigidum, appears a close relative of Sinocarum. Affinities of most Sino‐Himalayan Apioideae, therefore, are found among taxa from the same and adjacent territories. Wide disjunction between presumptively related taxa has been revealed only inCyclorhizaandKomarovia. SinodielsiaandMeeboldiaare also revealed to be clearly distinct genera.
Validation of the namesUtrechtiaceae,Utrechtia, andUtrechtia floriniformis
Authors: Rothwell Gar W. , Mapes Gene 
Published: February 2007

AbstractThe details of the type specimens ofU. floriniformisand their repository are reported in order to validly publish the namesUtrechtiaceaeMapes & G. W. Rothwell,UtrechtiaMapes & G. W. Rothwell, andUtrechtia floriniformisMapes & G. W. Rothwell.
Phylogenetic relationships in Ribes (Grossulariaceae) inferred from ITS sequence data
Authors: Senters Anne E. , Soltis Douglas E. 
Published: February 2007

AbstractNuclear ITS sequence data were employed to assess phylogenetic relationships within Ribes, an angiosperm genus of approximately 200 species that is well­known for its taxonomic complexity. Our analyses revealed several major clades within Ribes, informally referred to here as the Berisia, Calobotrya, Coreosma, and Grossularia sensu lato clades. The clades recovered indicate that some of the subgenera recognized in previous taxonomic treatments are largely monophyletic, including Calobotrya, Grossularia, and Grossularioides. Our data suggest broader circumscriptions of Lobbia, Berisia, and Coreosma. Other subgenera, such as Heritiera and Ribesia are likely polyphyletic, with constituent taxa scattered throughout the topology. The gooseberries in the broad sense (subgenera Grossularia, Hesperia, Lobbia and Robsonia), sometimes treated as a distinct genus Grossularia, are clearly embedded within Ribes and do not merit status as a separate genus. Comparison with a cpDNA topology reveals some similarities, such as the monophyly of subgenera Calobotrya and Grossularia and the inclusion of all gooseberries (Grossularia s.l.) within Ribes. There are also noteworthy differences. In contrast to both ITS sequence data and morphological data, cpDNA restriction site data do not reveal a monophyletic Grossularia sensu lato clade comprising subgenera Grossularia, Hesperia, Lobbia, and Robsonia. However, few of the differences between the cpDNA and ITS trees are strongly supported. Our ITS topology suggests that dioecy may have evolved several times in the genus. We similarly explored floral form in light of our topology; highly reflexed sepals represent a morphological synapomorphy that unites the subgenera Grossularia, Hesperia, Lobbia and Robsonia, with a reversal in a single taxon.
Chiangiodendron (Achariaceae): an example of the Laurasian flora of tropical forests of Central America
Authors: Sosa Victoria , Chase Mark W. , Barcenas Cristina 
Published: February 2007

AbstractUsing plastid rbcL DNA sequences, we evaluated relationships of the monotypic genus Chiangiodendron (C. mexicanum), which has been thought to be the only New World member of Flacourtiaceae, tribe Pangieae, by some authors. The analysis consisted of two steps. In the first, we analyzed the rbcL sequence of Chiangiodendron in a large eudicot matrix (more than 500 representatives). Based on these results, a second, restricted analysis with 142 taxa was conducted. Chiangiodendron belongs to tribe Pangieae (which is now recognized as part of Achariaceae, whereas the rest of former Flacourtiaceae fall into Salicaceae s.l.), making Chiangiodendron the only American representative of that tribe. Its closest relatives are from Asia. Chiangiodendron is a relict of a wet‐tropical Laurasian flora that has been preserved in Neotropical refugia.
Chromosome studies in the grass subfamily Chloridoideae. I. Basic chromosome numbers
Authors: Roodt Rouvay , Spies Johan J. 
Published: February 2007

AbstractTwo main basic chromosome numbers occur in the majority of southern African Chloridoideae, i.e., 9 and 10, the majority being x = 10. Two main evolutionary pathways, one following x = 10 and the other following an aneuploid/dysploid reduction to x = 9 are suggested for the subfamily. Evidence indicates that x = 9, 10 are paleopolyploid basic chromosome numbers, with x = 10 derived from x = 5. This corresponds to the closely related Panicoideae where five is accepted as the basic chromosome number.
Rediscovery of the first collection of the "Living Fossil",Metasequoia glyptostroboides
Authors: Ma Jinshuang , Shao Guofan 
Published: February 2007

AbstractLiving trees of the early Cenozoic taxonMetasequoia glyptostroboideswere first discovered in 1943. The first specimen that triggered its discovery, however, was lost. After three years of searching, we have located the first specimen stored in an unregistered, abandoned "herbarium" at the Jiangsu Forestry Academy (JFA), Nanjing, Jiangsu, China. This first specimen was collected by C. Wang (number 118) on 21 Jul 1943 from a large tree at Modaoxi, Wan Xian, Sichuan, also known as the type tree since the type was collected from the same tree by C. J. Hsueh in 1946.
Phylogenetic relationships in Asphodelaceae (subfamily Alooideae) inferred from chloroplast DNA sequences (rbcL, matK) and from genomic fingerprinting (ISSR)
Authors: Treutlein Jens , Smith Gideon F. , van Wyk Ben-Erik , Wink Michael 
Published: February 2007

AbstractTwo independent lines of molecular evidence have been studied to explore phylogenetic relationships in the family Asphodelaceae. Genomic fingerprinting by ISSR (Inter Simple Sequence Repeats) analysis was compared to sequence data of the chloroplast genes matK and rbcL. Molecular data indicate that some long­established taxonomic concepts would have to be re­evaluated. The subfamily Asphodeloideae clusters as a sister group to a distinctly monophyletic Alooideae. However, several Alooideae genera, including Aloe and Haworthia, are apparently not monophyletic. From a molecular point of view, Haworthia can be divided into two distinct groups that agree closely with the current subgeneric classification: a monophyletic group including species of subgenus Haworthia, and a second polyphyletic group with the subgenera Hexangulares and Robustipedunculares. This second clade includes Poellnitzia, Astroloba, Gasteria and even one Haworthia­like aloe (Aloe aristata). In the polyphyletic assemblage currently classified as Aloe, several smaller clades can be recognised, often reflecting morphological, chemical and geographical discontinuities. The tree aloes (sections Aloidendron and Dracoaloe) and climbing aloes (series Macrifoliae) appear to have separated early in Alooideae, while other groups (e.g., the flavonoid­containing group and a Madagascan group) are embedded within and amongst other genera. Chortolirion clusters with the grass­like aloes (section Graminialoe Reynolds, syn. Leptaloe Berger), A. boylei and A. verecunda , on a well­defined branch. The current taxonomic system clearly does not reflect the phylogenetic affinities and relationships amongst the succulent genera Aloe, Astroloba, Chortolirion, Gasteria, Haworthia, and Poellnitzia.
Proposal for a mercury isolation procedure using cold vapor method in combination with voltammetric determination using a rotating gold electrode
Authors: Chýlková Jaromíra , Šelešovská-Fadrná Renáta , Machalíková Jaroslava 
Published: February 2007

Abstract
The optimal process of pre-treatment and activation of gold rotating disc electrode (AuRDE) before voltammetric determination of mercury is proposed. This treatment encompasses polishing of the electrode surface, electrochemical cycling, and activation. This procedure both increases determination sensitivity as well as improves determination reproducibility. The detection limit on the working electrode achieved using this approach amounted to 8.26·10−10 mol L−1for direct mercury determination in water solution (applying 200 s running accumulation). The procedure of the quantitative mercury isolation from complicated sample matrix was developed as well. It provides better selectivity and significant increase of sensitivity of mercury determination. In case of mercury isolation from one liter of water the detection limit is 6.23·10−11 mol L−1 (analyzing a greater sample volume the determined concentration could be lower).
Human dental microwear from Ohalo II (22,500–23,500 cal BP), southern Levant
Authors: Mahoney Patrick 
Published: January 2007

AbstractDietary hardness and abrasiveness are inferred from human dental microwear at Ohalo II, a late Upper Palaeolithic site (22,500–23,500 cal BP) in the southern Levant. Casts of molar grinding facets from two human skeletons were examined with a scanning electron microscope. The size and frequency of microwear was measured, counted, and compared to four prehistoric human groups from successive chronological periods in the same region: pre‐pottery Neolithic A, Chalcolithic (this study); Natufian, pre‐pottery Neolithic B (Mahoney: Am J Phys Anthropol 130 (2006) 308–319). The Ohalo molars had a high frequency of long narrow scratches, and a few small pits, suggesting a tough abrasive diet that required more shearing rather than compressive force while chewing. These results imply that the diet of the two late Upper Palaeolithic hunter‐gatherers did not focus on very hard foods. Aquatic foods with adherent contaminants, as well as grit from plant grinding tools seemed likely causal agents. The size of the pits and scratches on the Ohalo molars were most similar to microwear from the pre‐pottery Neolithic A period, though they also compared well to the Chalcolithic period. These results contrasted with the larger pits and scratches from the Natufian hunter‐gatherers and pre‐pottery Neolithic B farmers, implying that there is no simple increase or decrease in dietary hardness and abrasiveness across the late Upper Palaeolithic to Chalcolithic development in the Southern Levant. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Palladium‐Katalysatorsysteme für die Synthese von konjugierten Eninen durch Sonogashira‐Kupplungen und verwandte Alkinylierungen
Authors: Doucet Henri , Hierso Jean‐Cyrille 
Published: January 2007

AbstractKonjugierte Alkine sind stets wiederkehrende Synthesebausteine in Naturstoffen, zahlreichen unverzichtbaren industriellen Zwischenstufen, in Pharmazeutika und Agrochemikalien sowie in molekularen Materialien für Optik und Elektronik. Daher zählt die palladiumkatalysierte Verknüpfung der sp2‐hybridisierten Kohlenstoffatome von Aryl‐, Heteroaryl‐ und Vinylhalogeniden mit den sp‐hybridisierten Kohlenstoffatomen von terminalen Acetylenen in einer Kreuzkupplung unbestreitbar zu den bedeutendsten Entwicklungen der Alkinchemie in den vergangenen fünfzig Jahren. Auf die grundlegenden Arbeiten der 1970er folgte eine intensive Suche nach allgemeineren und verlässlicheren Reaktionsbedingungen. Das Interesse an einer katalytischen Aktivierung anspruchsvoller Substrate, die unbedingte Notwendigkeit, den Ressourcenverbrauch zu minimieren, und die einfache Synthese einer stetig wachsenden Zahl an funktionalisierten Eninen führte allmählich zu den aktuellen Katalysatoren mit hohen Umsatzzahlen. Der vorliegende Aufsatz gibt einen Überblick über hoch wirksame Palladium‐Katalysatorsysteme für die direkte Alkinylierung von C(sp2)‐Halogeniden mit terminalen Alkinen in homogener oder heterogener Phase.
Palladium‐Based Catalytic Systems for the Synthesis of Conjugated Enynes by Sonogashira Reactions and Related Alkynylations
Authors: Doucet Henri , Hierso Jean‐Cyrille 
Published: January 2007

AbstractConjugated alkynes are recurring building blocks in natural products, a wide range of industrial intermediates, pharmaceuticals and agrochemicals, and molecular materials for optics and electronics. The palladium‐catalyzed cross‐coupling between sp2‐hybridized carbon atoms of aryl, heteroaryl, and vinyl halides with sp‐hybridized carbon atoms of terminal acetylenes is one of the most important developments in the field of alkyne chemistry over the past 50 years. The seminal work of the 1970s has initiated an intense search for more general and reliable reaction conditions. The interest in the catalytic activation of demanding substrates, the need to minimize the consumption of depletive resources, and the search for easy access to an increased variety of functionalized enynes has led to the current generations of high‐turnover catalysts. This Review gives an overview of the highly efficient palladium catalyst systems for the direct alkynylation of C(sp2) halides with terminal alkynes, both in homogeneous and heterogeneous phases.
Cotton fabric surface modification for improved UV radiation protection using sol–gel process
Authors: Abidi Noureddine , Hequet Eric , Tarimala Sowmitri , Dai Lenore L. 
Published: January 2007

AbstractIn this study, lightweight 100% cotton fabric was successfully modified by the sol–gel process to impart high ultraviolet radiation (UVR) scattering property to the fabric surface. Active ingredients were tetraethyl orthotitanate [Ti(OCH2CH3)4] and tetraethyl orthosilicate [Si(OCH2CH3)4]. The cotton fabric was padded with the nanosol solution, dried at 60°C, and cured at 150°C. Scanning electron microscopy showed continuous and uniform film on the fiber surface. Excellent UVR scattering was obtained with all treated fabrics. Increasing titania content in the nanosol solution leads to increased UVR protection. This is attributed to the increase of the refractive index of the film formed on the fabric surface. Excellent durability of the treatment was obtained, which indicates a good adhesion between the coating and the fabric surface. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 111–117, 2007.
Morphological analysis of the tiger stripe on injection molding of polypropylene/ethylene‐propylene rubber/talc blends dependent on based polypropylene design
Authors: Hirano Koki , Suetsugu Yoshiyuki , Kanai Toshitaka 
Published: January 2007

AbstractTiger stripe of injection molding of polypropylene (PP)/elastomer/talc blends was analyzed in terms of the morphology of the dispersed phase comprising elastomer components by using gloss and scanning electron microscopy (SEM). In addition, the contribution of the polymer design of PP, i.e., industrial block‐type grade consisting of a homo‐PP portion as the matrix and an ethylene propylene random copolymer portion as the domain is discussed. Local gloss measurement of the injected specimen along with the flow direction of the molten blends indicates a periodic fluctuation repeating higher and lower degrees of gloss, corresponding to the period of glossy and cloudy portions of the tiger stripe, respectively. These local gloss degrees are highly dependent on the morphologies of the dispersed phases near the surface layer of the injected specimen. The gloss increases when the ratio long axis (L) and diameter (D), L/D, of the dispersed phase are increased, and the gloss decreases when the L/D is decreased. Increasing the intrinsic viscosity of the ethylene‐propylene rubber portion of the PP is an effective design factor for restricting the deformation against shear strain during injection process by giving the dispersed phases high elasticity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 192–199, 2007