bluuebunny/crossref_metadata_2025 huggingface dataset:
Lucerne, phalaris, and wallaby grass in short-term pasture phases in two eastern Australian wheatbelt environments. 2. Effect of perennial density and species on subterranean clover populations and the relative success of 3 clover cultivars of different maturity
Authors: Dear B. S. , Sandral G. A. , Virgona J. M. , Swan A. D. , Orchard B. A. , Cocks P. S.
Published: May 2013

The effect of the density of 3 perennial species, phalaris (Phalaris aquatica L.), wallaby grass (Austrodanthonia richardsonii Kunth), and lucerne (Medicago sativa L.), on seed set, regeneration, and the relative competitiveness of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was examined in 2 environments in the south-eastern Australian wheatbelt.
Seed yields of subterranean clover were inversely related to perennial density at both sites over the first 2 years, the relationship varying with perennial species. Phalaris depressed the seed yield of clover more than lucerne and wallaby grass in the second and third year at equivalent densities. Clover seed yield was positively related to clover herbage yield in late spring at both sites, and inversely related to perennial herbage yield. Clover seed yield displayed an increasing linear relationship with the proportion of light reaching the clover understorey in spring, which in turn was inversely related to perennial density and perennial herbage yield.
Clover seedling regeneration in mixed swards in autumn was positively related to the size of the summer seed bank, but negatively related to perennial density. Clover seedling survival following a premature germination at Kamarah was inversely correlated to the density of phalaris and lucerne in the sward.
The relative competitiveness of the 3 subterranean clover cultivars varied between sites, with climatic conditions (rainfall and growing-season length) having a greater effect on the relative cultivar performance than companion perennial species or density. The later maturing subterranean clover cv. Goulburn became the dominant cultivar at the wetter site, constituting 72% of the seed bank, but declined to only 3–8% of the seed bank at the drier site. The proportion of the early flowering cultivar Dalkeith in the seed bank increased over time at the drier site and was highest (53%) in plots with the highest perennial density.
We concluded that although perennial pasture species will depress clover seed yield and subsequent regeneration, these effects could be minimised by reducing perennial densities and exploiting variations in competitiveness between perennial species as identified in this study. Sowing earlier maturing subterranean clover cultivars would only be an advantage in increasing clover content in low-rainfall environments. The findings suggest that clover seed reserves and regeneration could also be increased by using grazing management to reduce the level of shading of clover by perennials, a factor associated with reduced clover seed yield.
Resprouting and mortality of juvenile eucalypts in an Australian savanna: impacts of fire season and annual sorghum
Authors: Werner Patricia A. , Franklin Donald C.
Published: May 2013

In northern Australian savannas, canopy tree species often have juvenile tree banks that are composed mainly of small individuals of indeterminate age that have resprouted repeatedly after fire. Little is known about their demography. We report the initial responses (mortality, topkill and resprouting type) of 3133 marked juvenile eucalypts to set fires of different seasons (early dry season, late dry season, wet season, unburnt) in a 32 400 m2 field experiment. Fire treatments were repeated in plots dominated by a native annual grass (sorghum) that becomes senescent before the early dry season and provides the main fuel of savanna fires, and in others with little or no sorghum, but instead other native grasses and forbs that remain green well into the dry season. Most juvenile eucalypts <150 cm high were topkilled but resprouted from underground tissues regardless of fire season or understorey (86–100% vs <5% in unburnt plots). Few saplings 200–500 cm high died or were topkilled, but impacts of fire were harsher in sorghum than in non-sorghum vegetation. The response of eucalypts 150–199 cm high was intermediate, suggesting a ‘tactical’ transition from suppressed persistence to growth toward maturity. Counter-intuitively, genet death of juvenile trees was >22% in the low-intensity early dry season fire in plots with little or no annual sorghum, compared with <2% in all other fire/understorey combinations. We suggest results are related to fire behaviour, seasonal carbohydrate storage dynamics and competition with ground-layer plants.
Theoretical Investigation of Organic Amines as Hole Transporting Materials: Correlation to the Hammett Parameter of the Substituent, Ionization Potential, and Reorganization Energy Level
Authors: Pan Jiunn-Hung , Chou Yu-Ma , Chiu Houn-Lin , Wang Bo-Cheng
Published: May 2013

Theoretical calculations on organic amines widely used as hole-transporting materials (HTMs) in multilayer organic light-emitting diodes have been performed. The calculated Ip and the reorganization energy for hole transport (λ+) of triphenylamine (TPA), 9-phenyl-9H-carbazole (PC), and their derivatives, are found to be related to their Hammett parameter (σ). In this study, the density functional theory (DFT) calculation is used to optimize 82 TPA and PC derivatives. Electronic structures of these compounds in the neutral and the radical-cation states are obtained based on calculations on optimized geometrical structures. The Ip and λ+ values are derived from calculated heats of formation (or total energy) of the neutral and the radical-cation states. In particular, the calculated Ips for these derivatives correlate well with the experimental data. The substitution effect for the mono-substituted TPA and PC is displayed in that the Ips of the TPA and PC derivatives with electron-donating and -withdrawing substituents are lower and higher than those of TPA and PC, respectively. For the effect of substitution position, the para-substituted TPA derivatives have higher Ip and –EHOMO than those of meta-substituted TPAs. The substitution effects in di- and tri-substituted TPAs are more pronounced than that of mono-substituted ones. According to the results, the calculated Ips shows an excellent agreement with the experimental oxidation potentials (EP/2) in these TPA derivatives. Furthermore, these calculation results can be employed to predict electro-luminescent properties for new and improved HTMs.
Synthesis and Characterization of New N-Alkylamino-3,5-diphenylpyrazole Ligands and Reactivity Toward PdII and PtII. Study of the cis–trans Isomerization
Authors: Aragay Gemma , Pons Josefina , Branchadell Vicenç , García-Antón Jordi , Solans Xavier , Font-Bardía Mercé , Ros Josep
Published: May 2013

In this paper, the synthesis and characterization of two new N-alkylaminopyrazole ligands, 1-[2-(ethylamino)ethyl]-3,5-diphenylpyrazole (dpea) and 1-[2-(octylamino)ethyl]-3,5-diphenylpyrazole (dpoa) are reported. The reaction of these ligands with [MCl2(CH3CN)2] (M = PdII, PtII) affords the following square planar complexes: cis-[MCl2(NN′)] (M = PdII: NN′ = dpea, 1; dpoa, 2; M = PtII: NN′ = dpea, 3; dpoa, 4). Reaction of [PdCl2(CH3CN)2] and dpea or dpoa in 1:2 M:NN′ molar ratio, in the presence of NaBF4, yields complexes [Pd(NN′)2](BF4)2 (NN′ = dpea, [5](BF4)2); dpoa, [6](BF4)2). The solid-state structures of complexes 1, 3, and [5](BF4)2 have been determined by single-crystal X-ray diffraction methods. In complexes 1 and 3, the dpea ligand is coordinated through the Npz and Namino atoms to the metallic centre, which completes its coordination with two chlorine atoms in a cis disposition. For complex [5](BF4)2, the crystal structure consists of cations involving a [Pd(Npz)2(Namino)2]2+ core with a cis disposition of the two dpea ligands in a square-planar geometry and BF4
– anions. Theoretical calculations were carried out to optimize the geometries of the cis and trans isomers of the [Pd(dpea)2]2+ cation and of the [Pd(dpea)2](BF4)2 complex. The results show that the trans isomer is the most stable for [Pd(dpea)2]2+, in contrast with the cis stereochemistry observed in the crystal structure of [Pd(dpea)2](BF4)2. The calculations also predict that in acetonitrile solution, the dissociation of this complex into the corresponding ions is thermodynamically favourable. The cis–trans isomerization process of [Pd(dpea)2]2+ in acetonitrile solution has been studied by NMR spectroscopy at different temperatures. These experimental results confirm that the trans isomer is the thermodynamically most stable form of the complexes [5](BF4)2 and [6](BF4)2.
Steroidal Saponins Isolated from an Australian Yam Dioscorea sp.
Authors: Challinor Victoria L. , Smith David M. , De Voss James J.
Published: May 2013

Phytochemical characterization of the rhizome of an Australian species of Dioscorea, acquired as Dioscorea transversa R Br. but botanically identified as Dioscorea sp., led to the isolation of two steroidal saponins. The major constituent 1β-hydroxyprotogracillin (1) was previously unknown while the minor one was identified as protogracillin (2). The structure and stereochemistry of 1 were elucidated using a combination of MS studies, 1D and 2D NMR experiments and chemical degradation.
Intramolecular Hydroamination of Aminoalkenes using Rhodium(I) and Iridium(I) Complexes with N,N- and P,N-Donor Ligands
Authors: Nguyen Thi O. , Man Bradley Y.-W. , Hodgson Richard , Messerle Barbara A.
Published: May 2013

Cationic rhodium(i) and iridium(i) complexes containing the bidentate heterocyclic N,N-donor ligand bis(1-pyrazolyl)methane (bpm) and the counterion tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (BArF–) were found to be efficient catalysts for the cyclization of activated and unactivated aminoalkenes. The rates of cyclization were found to be highly dependent upon the size and steric bulk of the substituents at the γ-position of the aminoalkene, with large steric bulk leading to faster rates of cyclization. In comparison, analogous rhodium(i) and iridium(i) complexes with the mixed P,N-donor ligand 1-[2-(diphenylphosphino)ethyl]pyrazole (PyP) were found to be less effective as catalysts for this reaction.
An Ab Initio Investigation of the Chain-Length Dependence of the Addition–Fragmentation Equilibria in RAFT Polymerization
Authors: Lin Ching Yeh , Coote Michelle L.
Published: May 2013

Ab initio molecular orbital theory has been used to study and explain the effects of chain length on the addition–fragmentation equilibrium constant in reversible addition–fragmentation chain transfer (RAFT) polymerization. New data is presented for azobisisobutyronitrile-initiated t-butyl dithiobenzoate-mediated polymerization of methyl methacrylate, and 2-(((ethylthio)carbonothioyl)thio)propanoic acid-mediated polymerization of acrylamide, and compared with published results for a dithiobenzoate-mediated polymerization of styrene and a trithiocarbonate-mediated polymerization of methyl acrylate. The effects of primary and penultimate substituents on the addition–fragmentation equilibrium constants in RAFT polymerization can be very large (up to eight orders and four orders of magnitude respectively) and should be taken into account in kinetic models. Antepenultimate unit effects are relatively small, implying that, for most systems, chain length effects have largely converged by the dimer stage. However, for sterically bulky monomers capable of undergoing anchimeric interactions such as hydrogen bonding, the onset and convergence of these substituent effects is delayed to slightly longer chain lengths. The magnitude and direction of chain-length effects in the addition–fragmentation equilibrium constants varies considerably with the nature of the RAFT agent, the initiating species, the propagating radical, and the solvent. The observed substituent effects arise primarily in the differing stabilities of the attacking radicals, but are further modified by homoanomeric effects and, where possible, hydrogen-bonding interactions.
Halogenated Terpenoids. XXIII. The Dichlorocineoles
Authors: Carman RM , Fletcher MT
Published: May 2013

Eleven dichlorides of cineole have been synthesized. Spectral data for the compounds are listed.
Polyfluoroalkyl compounds in the Canadian Arctic atmosphere
Authors: Ahrens Lutz , Shoeib Mahiba , Del Vento Sabino , Codling Garry , Halsall Crispin
Published: May 2013

Environmental contextPerfluoroalkyl compounds are of rising environmental concern because of their ubiquitous distribution in remote regions like the Arctic. The present study quantifies these contaminants in the gas and particle phases of the Canadian Arctic atmosphere. The results demonstrate the important role played by gas–particle partitioning in the transport and fate of perfluoroalkyl compounds in the atmosphere.
AbstractPolyfluoroalkyl compounds (PFCs) were determined in high-volume air samples during a ship cruise onboard the Canadian Coast Guard Ship Amundsen crossing the Labrador Sea, Hudson Bay and the Beaufort Sea of the Canadian Arctic. Five PFC classes (i.e. perfluoroalkyl carboxylates (PFCAs), polyfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs)) were analysed separately in the gas phase collected on PUF/XAD-2 sandwiches and in the particle phase on glass-fibre filters (GFFs). The method performance of sampling, extraction and instrumental analysis were compared between two research groups. The FTOHs were the dominant PFCs in the gas phase (20–138 pg m–3), followed by the FOSEs (0.4–23 pg m–3) and FOSAs (0.5–4.7 pg m–3). The PFCAs could only be quantified in the particle phase with low levels (<0.04–0.18 pg m–3). In the particle phase, the dominant PFC class was the FOSEs (0.3–8.6 pg m–3). The particle-associated fraction followed the general trend of: FOSEs (~25 %) > FOSAs (~9 %) > FTOHs (~1 %). Significant positive correlation between ∑FOSA concentrations in the gas phase and ambient air temperature indicate that cold Arctic surfaces, such as the sea-ice snowpack and surface seawater could be influencing FOSAs in the atmosphere.
Environmental levels and distribution of structural isomers of perfluoroalkyl acids after aqueous fire-fighting foam (AFFF) contamination
Authors: Kärrman A. , Elgh-Dalgren K. , Lafossas C. , Møskeland T.
Published: May 2013

Environmental contextPerfluoroalkyl acids are used in many products and have spread into the environment where their persistence and potential toxicity pose a threat to humans and wildlife. The present study describes environmental contamination from usage of aqueous film forming foams, and investigates the distribution of structural isomers of perfluoroalkyl acids from a point source to the surrounding environment. Isomer patterns might be used to track contamination sources since isomer composition differs in the various products containing perfluoroalkyl acids. The environmental behaviour of these structural isomers is described, and limitations of their use to track contamination sources are identified.
AbstractThe environment (soil, water, sediment, fish, crab and mussel) around a training facility using aqueous film forming foams (AFFFs) was studied with respect to perfluorinated alkyl acids (PFAAs) and 6 : 2 fluorotelomer sulfonate (FTS) and their structural isomers. High levels of many PFAAs and 6 : 2 FTS were detected in soil, seepage water, sediment and fish liver. Structural isomers were found for sulfonates, except PFBuS, and for PFOA. Quantification using authentic standards revealed an isomer pattern of 63% linear PFOS (L-PFOS) and 80% linear PFOA (L-PFOA) in the soil at the contamination site, which indicated a source produced by electrochemical fluorination (ECF). The 6 : 2 FTS was 100% linear in all compartments thus coming from a telomerisation product. Enrichment of the linear structure of PFOS and PFOA in soil was seen with increasing distance from the training centre, and an enrichment of branched isomers for both compounds could be found in the seepage water. Sorption to sediment and accumulation in fish liver led to an enrichment of L-PFOS whereas all PFOA remained in the water body.
Perfluoroalkyl and polyfluoroalkyl substances: current and future perspectives
Authors: Kannan Kurunthachalam
Published: May 2013

Environmental contextPerfluoroalkyl substances were recognised as global environmental pollutants 10 years ago. Although considerable advancements have been made in our understanding of the environmental distribution, fate and toxicity of perfluoroalkyl substances, several important issues remain to be resolved. This article identifies existing knowledge gaps that deserve further investigations to enable meaningful regulatory decisions.
AbstractIt has been over a decade since perfluoroalkyl substances (PFASs) were discovered as global environmental contaminants. Considerable progress has been made in our understanding of the environmental fate and toxic effects of PFASs since then. Government regulations and voluntary emission reduction initiatives by industry have been effective in reducing environmental and human exposure to a major PFAS, perfluorooctane sulfonate (PFOS), in the United States and several other western countries. Although significant advances have been made in our understanding of the environmental chemistry of PFASs, considerable knowledge gaps still exist in several areas of environmental fate and risk assessments. Owing to their complex chemistry, involving existence of multiple precursors with significant numbers of structural isomers and mixtures of homologues, multiple degradation pathways and unique physicochemical properties, challenges remain in elucidating sources and environmental fate. In this overview, some of the knowledge gaps in PFASs’ research have been identified and suggestions for future research have been made.
Nitrogen and oxygen isotope effects of tissue nitrate associated with nitrate acquisition and utilisation in the moss Hypnum plumaeforme
Authors: Liu Xue-Yan , Koba Keisuke , Yoh Muneoki , Liu Cong-Qiang
Published: May 2013

Mosses are effective accumulators and indicators of N deposition, but the mechanisms of moss N utilisation remain unclear. This study monitored nitrate concentrations ([NO3–]) in solutions supplied to Hypnum plumaeforme Wils. to characterise NO3– uptake from rain events. Concentrations and isotopic ratios (δ15N and δ18O) of residual NO3– in moss tissues were measured to interpret induced NO3– reduction. Noninduced NO3– reduction was inferred from endogenous [NO3–] and isotopic variations that occurred during 65 days of N deprivation. H. plumaeforme scavenges NO3– effectively from supplied solutions. The uptake rate increased with substrate [NO3–] (0.4−3.9 mg N L–1) and generally obeyed saturation (Michaelis–Menten) kinetics. The uptake rate was maximised within 60 min after receiving NO3–, irrespective of the initial substrate [NO3–]. Lower tissue [NO3–] and greater isotopic enrichment verified the inducibility of nitrate reductase activity (NRA) by NO3– availability, but short-term darkness did not markedly influence moss NO3– uptake or reduction. Significant reduction and isotopic enrichment were detected in moss NO3– reserves during N deprivation, showing 15ε of 12.1‰ and 18ε of 14.4‰. The Δδ15N : Δδ18O ratios of ~1 : 1 implied that NRA is the single process driving 15N and 18O fractionations. These results provide new isotopic insights into the nitrate reductase dynamics of the moss.
Genotypic variation in the accumulation of water soluble carbohydrates in wheat
Authors: McIntyre C. Lynne , Seung David , Casu Rosanne E. , Rebetzke Gregory J. , Shorter Ray , Xue Gang Ping
Published: May 2013

Water-soluble carbohydrates (WSC) stored in the stems and leaf sheaths of winter cereals provide an important source of assimilate for remobilisation during grain-filling. Consequently, WSC are a major contributor to wheat grain yield and grain size in all environments but especially where photosynthesis is compromised as occurs where water is limiting. Breeding programs targeting greater WSC should provide improved varieties with greater and more stable yields in stress environments. To facilitate selection for WSC, genetic and genomic approaches are being used to determine the genetic basis of – and define DNA probes for – marker-aided selection for this important drought-adaptive trait. Empirical studies have identified both WSC concentration and content to be under complex genetic control of many genes. Quantitative trait loci (QTL) for WSC have been identified in several wheat populations with individual QTL explaining small amounts of phenotypic variation, typically of less than 20%. Many of these QTL are common across multiple, genetically-unrelated wheat populations. Evaluation of gene expression in high and low WSC wheat progeny lines from a well characterised wheat population has identified significant differences in expression of genes from different gene categories. For example, high WSC progeny lines have higher levels of expression of genes involved in carbohydrate metabolism and lower levels of expression of genes involved in cell wall and amino acid metabolism than low WSC lines. Genetic mapping reveals several candidate genes co-locating with QTL for WSC. In addition, expression QTL (eQTL) for selected candidate genes co-locate with WSC QTL; co-location of the genes and eQTL with WSC QTL make these genes stronger candidate genes for the WSC trait.
Phylogeny and taxonomy of the Rhinorhynchinae (Coleoptera:Nemonychidae)
Authors: Kuschel Guillermo , Leschen Richard A. B.
Published: May 2013

An overview of the taxa of Rhinorhynchinae (Nemonychidae) is presented. A phylogenetic analysis of the 19 extant genera of the Rhinorhynchinae and one fossil genus from the Lower Cretaceous (Cratomacer Zherikhin & Gratshev), based on 29 characters of adults, larvae and host plant associations, shows three monophyletic groups, treated as tribes (Rhinorhynchini, Mecomacerini and Rhynchitomacerini). Primitive associations are unknown for Rhinorhynchinae and early host use diversification included associations with Ranunculaceae (Nemonyx Redtenbacher), Pinaceae (Cimberis Gozis), Nothofagaceae (Rhynchitomacerini) and Podocarpaceae (Rhinorhynchini). While Mecomacerini diversified on Araucariaceae, within Rhinorhynchini there was a single reversal to Araucariaceae and a shift in Atopomacer Kuschel to Pinaceae. Placement of Cratomacer into Mecomacerini is consistent with geological and molecular data that suggest gymnosperms may have been the primitive hosts for the family. Three new genera are described in Rhinorhynchinae: Araucomacer, gen. nov. (type species A. hirticeps Kuschel) from Chile, Idiomacer, gen. nov. (type species I. basicornis, sp. nov.) from New Caledonia, and Zimmiellus, gen. nov. (type species Z. fronto, sp. nov.) from Queensland, Australia, while Stenomacer Kuschel, stat. nov. from Chile is reinstated from synonymy. Seven species are described as new: Atopomacer grandifurca, sp. nov. from Costa Rica and Panama, A. obrieni, sp. nov. from Mexico, A. panamensis, sp. nov. from Panama, A. pini, sp. nov. from Mexico, A. podocarpi, sp. nov. from Venezuela, Basiliogeus dracrycarpi, sp. nov. from western New Guinea and B. inops, sp. nov. from Queensland. Rhynchitomacer rufus Kuschel is a new junior subjective synonym of R. nigritus Kuschel, syn. nov., R. viridulus Kuschel is a new junior subjective synonym of R. flavus Voss, syn. nov. and Stenomacer fuscus Kuschel is a new junior subjective synonym of S. vernus Kuschel, syn. nov. Keys to genera of Rhinorhynchinae and to species of Atopomacer, Rhynchitomacer and Stenomacer are included. Diagnoses of the three extant subfamilies of Nemonychidae are included.
Systematic revision and cladistic analysis of the Brazilian subfamily Sodreaninae (Opiliones:Gonyleptidae)
Authors: Pinto-da-Rocha Ricardo , Bragagnolo Cibele
Published: May 2013

Sodreaninae is reviewed and all ten species are combined under its type genus, Sodreana Mello-Leitão, 1922, according to a cladistic analysis of morphological characters, which revealed a pectinate pattern of clades. The subfamily is endemic to the Brazilian Atlantic rainforest from Santa Catarina state to Rio de Janeiro state. Sodreana is herein considered a senior synonym of Stygnobates Mello-Leitão, 1927, Zortalia Mello-Leitão, 1936, Gertia B. Soares & H. Soares, 1946 and Annampheres H. Soares, 1979. The following new combinations are proposed: Sodreana barbiellinii (Mello-Leitão, 1927), Sodreana hatschbachi (B. Soares & H. Soares, 1946), Sodreana inscripta (Mello-Leitão, 1939), Sodreana leprevosti (B. Soares & H. Soares, 1947b), Sodreana bicalcarata (Mello-Leitão, 1936). Sodreana granulata (Mello-Leitão, 1937) is revalidated from the synonymy of Sodreana sodreana Mello-Leitão, 1922. Three new species are described: Sodreana glaucoi from Ilhabela and Boraceia, São Paulo state; S. curupira from Parque Nacional da Serra dos Órgãos, Rio de Janeiro state, and S. caipora from Ubatuba, São Paulo state. Sodreaninae species are restricted to forested areas and most occur in the southern part of the coastal Atlantic rainforest, one species occurs in interior Atlantic rainforest. The biogeographical analysis (Brooks Parsimony Analysis) resulted in a single and fully resolved most parsimonious tree with three main: components: northern (Bahia and Serra do Espinhaço), southern (Santa Catarina, Paraná, Serra do Mar of São Paulo), and central (Espírito Santo, Serra da Bocaina, southern state of Rio de Janeiro, Serra dos Órgãos, Serra da Mantiqueira, Serra do Mar of São Paulo).
Resolving the phylogenetic position of enigmatic New Guinea and Seychelles Scutigeromorpha (Chilopoda): a molecular and morphological assessment of Ballonemini
Authors: Butler Aodhán D. , Edgecombe Gregory D. , Ball Alexander D. , Giribet Gonzalo
Published: May 2013

Recent phylogenetic analyses of scutigeromorph centipedes omitted New Guinea endemics for lack of modern data, either from morphology or molecular sequences. Among these is the tribe Ballonemini, originally established for Ballonema Verhoeff, 1904, and Parascutigera Verhoeff, 1904, based on similar tergal prominences. Subsequent systematic revision led to their separation into different subfamilies. Combined analyses of morphology and sequence data including Ballonema gracilipes Verhoeff, 1904, resolve Ballonema either in a grade of Scutigerinae or as sister to all other Scutigerinae + Thereuoneminae. Confocal laser scanning microscopy (CLSM) of the types of B. gracilipes demonstrates the utility of this technique for non-destructive imaging of historical museum material at a resolution comparable to scanning electron microscopy. A possible record of Ballonema in the Seychelles is dismissed; a collection from Silhouette samples a member of Thereuoneminae described as Seychellonema gerlachi, gen. nov. sp. nov. Morphological data, analysed with sequence data for other Scutigeromorpha, ally Seychellonema with the Oriental–Australian genus Thereuopoda Verhoeff, 1904, but it displays a novel patterning of its tergal spinula and tarsal papillae. The phylogenetic analyses include sequence data for African Pselliodidae, corroborating a sister group relationship to remaining Scutigeromorpha and generating a more stable result than in earlier analyses using only Neotropical species.
Climate change impedes scleractinian corals as primary reef ecosystem engineers
Authors: Wild Christian , Hoegh-Guldberg Ove , Naumann Malik S. , Colombo-Pallotta M. Florencia , Ateweberhan Mebrahtu , Fitt William K. , Iglesias-Prieto Roberto , Palmer Caroline , Bythell John C. , Ortiz Juan-Carlos , Loya Yossi , van Woesik Robert
Published: May 2013

Coral reefs are among the most diverse and productive ecosystems on our planet. Scleractinian corals function as the primary reef ecosystem engineers, constructing the framework that serves as a habitat for all other coral reef-associated organisms. However, the coral’s engineering role is particularly susceptible to global climate change. Ocean warming can cause extensive mass coral bleaching, which triggers dysfunction of major engineering processes. Sub-lethal bleaching results in the reduction of both primary productivity and coral calcification. This may lead to changes in the release of organic and inorganic products, thereby altering critical biogeochemical and recycling processes in reef ecosystems. Thermal stress-induced bleaching and subsequent coral mortality, along with ocean acidification, further lead to long-term shifts in benthic community structure, changes in topographic reef complexity, and the modification of reef functioning. Such shifts may cause negative feedback loops and further modification of coral-derived inorganic and organic products. This review emphasises the critical role of scleractinian corals as reef ecosystem engineers and highlights the control of corals over key reef ecosystem goods and services, including high biodiversity, coastal protection, fishing, and tourism. Thus, climate change by impeding coral ecosystem engineers will impair the ecosystem functioning of entire reefs.
Some Recent Developments in Atomic Lifetime Determinations
Authors: Hannaford P , Lowe RM
Published: May 2013

A lifetimes technique that is readily applicable to neutral and singly ionised atoms of a wide range of elements, including the highly refractory elements, is reviewed. With this technique an atomic vapour of the element under study is generated by cathodic sputtering in a low pressure rare-gas discharge and fluorescence decay signals emitted by the vapour following pulsed laser excitation are recorded directly in a fast transient digitiser. Theoretical expressions are presented for the form of the time-resolved fluor~scence signal appropriate to the collisional environment of a rare-gas sputtering discharge. A summary is given of the atomic systems studied to date using this technique, and some new results for Sm and Ba are compared with recently reported results for these elements.
Evidence for cross-talk between the LH receptor and LH during implantation in mice
Authors: Gridelet Virginie , Tsampalas Marie , Berndt Sarah , Hagelstein Marie-Thérèse , Charlet-Renard Chantal , Conrath Valérie , Ectors Fabien , Hugé Fabian , Munaut Carine , Foidart Jean-Michel , Geenen Vincent , Perrier d'Hauterive Sophie
Published: May 2013

The present study investigated the first interaction that occurs between the blastocyst and endometrium during implantation. Given the ethical objections to studying implantation in humans, a mouse model was used to study the dialogue between luteinising hormone (LH) and luteinising hormone receptor (LHCGR). Several studies performed on LHCGR-knockout mice have generated controversy regarding the importance of the dialogue between LH and LHCGR during implantation. There has been no demonstration of a bioactive LH-like signal produced by the murine blastocyst. The first aim of the present study was to examine and quantify, using radioimmunoassay, the generation of a bioactive LH signal by the murine blastocyst. We went on to examine and quantify endometrial Lhcgr expression to validate the mouse model. Expression of LHCGR in mouse uteri was demonstrated using immunohistochemistry and western blot analysis. To quantify the expression of Lh in the mouse blastocyst and Lhcgr in the endometrium, reverse transcription–polymerase chain reaction (RT-PCR) and real-time quantitative (q) RT-PCR were performed. The results demonstrate that Lhcgr expression in BALB/c mouse endometrial epithelium is increased at the time of implantation and indicate that LHCGR may contribute to the implantation process. In support of this hypothesis, we identified a bioactive LH signal at the time of murine blastocyst implantation.
Spermatogenesis is seasonal in the large hairy armadillo, Chaetophractus villosus (Dasypodidae, Xenarthra, Mammalia)
Authors: Luaces Juan P. , Rossi Luis F. , Merico Valeria , Zuccotti Maurizio , Redi Carlo A. , Solari Alberto J. , Merani Maria S. , Garagna Silvia
Published: May 2013

Very little is known about the distinct reproductive biology of armadillos. Very few studies have investigated armadillo spermatogenesis, with data available only for Euphractus sexcinctus and Dasypus novemcinctus. In the present study, we analysed male germ cell differentiation in the large hairy armadillo Chaetophractus villosus throughout the year, describing a cycle of the seminiferous epithelium made of eight different stages. Evaluation of the testis/body mass ratio, analysis of the architecture of the seminiferous epithelium and the frequency of defective seminiferous tubules allowed identification of a temporal interruption of spermatogenesis during the period between mid-May to July (mid–end autumn) in correlation with very low testosterone levels. Overall, these results suggest that spermatogenesis is seasonal in C. villosus.
In vivo embryo production in cows superovulated 1 or 2 days after ovum pick-up
Authors: Surjus Ricardo S. , Prata Alexandre B. , Borsato Marta , Mattos Fernanda C. S. Z. , Martins da Silveira Mariana C. , Mourão Gerson B. , Pires Alexandre V. , Wiltbank Milo C. , Sartori Roberto
Published: May 2013

The present study evaluated superovulatory responses and in vivo embryo production in cows treated with FSH starting 1 or 2 days after ovum pick-up (OPU). Thirty-three non-lactating Nelore cows were subjected to aspiration of all follicles ≥3 mm for OPU. After OPU, cows were randomly divided into two groups in which the follicle superstimulatory treatments with FSH started 1 or 2 days after OPU (Groups D1 and D2, respectively). Data are presented as the least squares mean ± s.e.m. The number of follicles ≥3 mm before OPU was similar between groups (~34); however, cows in Group D2 had more follicles ≥3 mm on the first day of FSH (15.2 ± 2.3 vs 7.6 ± 1.7; P = 0.04) and a higher ratio of the number of follicles at first FSH/number of follicles before OPU (0.41 ± 0.04 vs 0.24 ± 0.02; P = 0.01). In addition, Group D2 cows had a greater superovulatory response than did cows in Group D1 (18.9 ± 2.8 vs 9.1 ± 1.9 corpora lutea, respectively; P < 0.03). However, there was no difference in the total number of recovered ova and embryos from cows in Groups D2 and D1 (5.1 ± 1.4 vs 4.9 ± 1.3, respectively; P > 0.10). Nevertheless Group D2 cows had more freezable embryos than Group D1 cows (3.2 ± 1.1 vs 1.3 ± 0.5, respectively; P < 0.05). Cows from Group D2 had a much higher proportion (P < 0.001) of follicles ≥8 mm compared with follicles ≥6 mm and <8 mm at the time of the last treatment with FSH. In conclusion, to obtain a greater production of viable embryos in superovulated cows after OPU, it is recommended to wait at least 2 days before starting FSH treatment.
Embryo development and sex ratio of in vitro-produced porcine embryos are affected by the energy substrate and hyaluronic acid added to the culture medium
Authors: Torner Eva , Bussalleu Eva , Briz M. Dolors , Yeste Marc , Bonet Sergi
Published: May 2013

In the present study, the effects of replacing glucose with pyruvate–lactate and supplementing these in vitro culture (IVC) media with hyaluronic acid (HA) on porcine embryo development and sex ratio were examined. The in vitro-produced (IVP) porcine embryos were cultured in NCSU-23 medium with 0.0, 0.5 or 1.0 mg mL–1 HA, and with either 5.55 mM glucose (IVC-Glu) or pyruvate (0.17 mM)–lactate (2.73 mM) from 0 to 48 h post insemination (h.p.i.) and then with glucose from 48 to 168 h.p.i. (IVC-PL). Those embryos cultured with IVC-PL had significantly higher blastocyst rates (23.7 ± 1.5%) than those cultured with IVC-Glu (14.27 ± 2.75%). At 1.0 mg mL–1, HA tended to skew the sex ratio of blastocysts towards males in those embryos cultured in IVC-PL, and led to a significant decrease in the blastocyst rate compared with embryos cultured in the presence of 0.5 and 0.0 mg mL–1 HA and IVC-Glu (4.28 ± 0.28% vs 11.01 ± 1.42% and 10.14 ± 2.77%, respectively) and IVC-PL (14.37 ± 1.35% vs 20.96 ± 2.85% and 22.99 ± 1.39%, respectively). In contrast, there were no significant differences in the total cell number per blastocyst or in apoptosis rates. In conclusion, pyruvate and lactate were the preferred energy substrates in the early stages of IVP porcine embryos. Moreover, 1.0 mg mL–1 HA significantly decreased the percentage of blastocyst rates in both the IVC-Glu and IVC-PL groups, but only by a preferential loss of female embryos for those cultured in IVC-PL.
Spectral and wavelet analysis of gilgai patterns from air photography
Authors: Milne A. E. , Webster R. , Lark R. M.
Published: May 2013

Gilgais form repeating patterns that seem to be regular to some degree. We have analysed the patterns of gilgais as they appear on aerial photographs of the Bland Plain of New South Wales to discover to what degree they exhibit regularity and to estimate the spatial frequencies of the repeating patterns. We digitised rectangular sections of the photographs to produce grids of pixels at 0.063-mm intervals, equivalent to 1.3 m on the ground, with the optical density of each pixel recorded as a level of grey in the range 0 (black) to 255 (white). From the data we computed autocorrelograms and power spectra in both 1 and 2 dimensions and wavelet coefficients and wavelet packet coefficients and their variances.
Spectra of many of the individual rows of the grids contained peaks corresponding to wavelengths of ≈32 m (at Caragabal) and ≈52 m (at Back Creek). The 2-dimensional spectra have rings of relatively large power corresponding to these wavelengths in addition to their central peaks. The 1-dimensional wavelet variances have pronounced peaks at the 16–32 pixel scale, corresponding to 20–40 m on the ground. The 2-dimensional wavelet analyses revealed peaks in the variances in the same range. Back Creek has in addition a low-frequency feature caused by the much darker than average gilgais in one corner of the digitised rectangle, and this is equally evident in the 1-dimensional analyses of rows that cross this corner, where the largest contribution to wavelet packet variation is at wavelength 84–167 m. Where this feature is absent, the best wavelet packet basis indicates that variation at frequencies at or below the repeating pattern is consistent with an underlying stationary random variable, while higher-frequency components show more complex (non-stationary) behaviour. We conclude that the gilgai patterns we have examined have a regularity with wavelengths in the range 30–50 m.
Carbon stock in the solum of some coarse-textured soils under secondary forest, grassland fallow, and bare footpath in the derived savanna of south-eastern Nigeria
Authors: Obalum S. E. , Watanabe Y. , Igwe C. A. , Obi M. E. , Wakatsuki T.
Published: May 2013

Quantitative data on carbon stock (C stock) in and beyond the topsoil (0–30 cm) under natural terrestrial ecosystems in West African savanna could provide information about their relative potential, and management options, for C sequestration, but these data are still scanty in the region. In selected locations (Nsukka, Obimo, and Ibagwa-aka) in the derived savanna zone of south-eastern Nigeria, secondary forest (SFT), grassland fallow (GLF), and bare footpath (BFP) were sampled from the topsoils (0–30 cm) and subsoils (30–60 cm) in triplicate. The soils are generally sandy, with low (1.4–13.8%) mean silt content. Mean bulk density ranged from 1.30 to 1.83 Mg/m3. The soils were acidic (pHwater 4.0–4.8) and low in organic C (0.10–1.14%). There was a consistent trend in C stock (SFT > GLF > BFP) in the topsoil, whereas only higher values in SFT than BFP were consistent in the subsoil. In both soil layers, the scale of the differences among the land-cover types was location-specific. Values of C stock were higher in the topsoil than subsoil, except for GLF and BFP at Obimo due to recent bush burning. Irrespective of location, the mean topsoil–subsoil values under SFT, GLF, and BFP were 45.7–30.6, 27.7–25.8, and 19.0–18.8 Mg/ha, respectively. Soil structural stability, indexed as the ratio of organic matter to silt + clay, explained roughly 61 and 89% of the variability in C stock of topsoils and subsoils, respectively. These results should benefit the planning of C sequestration projects in savanna agroecosystems of West Africa.
Modelling long-term fire regimes of southern California shrublands
Authors: Peterson Seth H. , Moritz Max A. , Morais Marco E. , Dennison Philip E. , Carlson Jean M.
Published: May 2013

This paper explores the environmental factors that drive the southern California chaparral fire regime. Specifically, we examined the response of three fire regime metrics (fire size distributions, fire return interval maps, cumulative total area burned) to variations in the number of ignitions, the spatial pattern of ignitions, the number of Santa Ana wind events, and live fuel moisture, using the HFire fire spread model. HFire is computationally efficient and capable of simulating the spatiotemporal progression of individual fires on a landscape and aggregating results for fully resolved individual fires over hundreds or thousands of years to predict long-term fire regimes. A quantitative understanding of the long-term drivers of a fire regime is of use in fire management and policy.
Effects of salvage logging and pile-and-burn on fuel loading, potential fire behaviour, fuel consumption and emissions
Authors: Johnson Morris C. , Halofsky Jessica E. , Peterson David L.
Published: May 2013

We used a combination of field measurements and simulation modelling to quantify the effects of salvage logging, and a combination of salvage logging and pile-and-burn fuel surface fuel treatment (treatment combination), on fuel loadings, fire behaviour, fuel consumption and pollutant emissions at three points in time: post-windstorm (before salvage logging), post-salvage logging and post-surface fuel treatment (pile-and-burn). Salvage logging and the treatment combination significantly reduced fuel loadings, fuelbed depth and smoke emissions. Salvage logging and the treatment combination reduced total surface fuel loading (sound plus rotten) by 73 and 77%. All fine woody fuels (<7.6cm) were significantly reduced by salvage logging and the treatment combination. In contrast, there was significant increase in the 1000-h (7.6–22.9cm) fuel loading. Salvage logging and the treatment combination reduced mean fuelbed depth by 38 and 65%. Salvage logging reduced PM2.5 emissions by 19%, and the treatment combination reduced emissions by 27%. Salvage logging and the treatment combination reduced PM10 emissions by 19 and 28%. We observed monotonic changes in flame length, reaction intensity and rate-of-spread after salvage logging and treatment combination. Study results illustrate potential differences between the effects of salvage logging after windstorms and the effects of salvage logging after wildfire.
Effects of tourist pressure and reproduction on physiological stress response in wildcats: management implications for species conservation
Authors: Piñeiro Ana , Barja Isabel , Silván Gema , Illera Juan Carlos
Published: May 2013

Context
Ecotourism and human recreational activities are increasing and can have a significant impact on fauna. The analysis of faecal glucocorticoid concentrations is a non-invasive method of measuring physiological stress responses of wildlife to various factors (i.e. human disturbances).

Aims
The aim of the present study was to determine whether increased physiological stress levels in wildcats (Felis silvestris) were a response to the level of tourism allowed within different zones in a natural park and/or a response to the seasonal reproductive state of wildcats.

Methods
The study was conducted from May 2005 to June 2009 at the Natural Park Montes do Invernadeiro (north-western Spain). The Natural Park is divided into the following three zones according to the level of tourism allowed: restricted public-use, restricted zone and integral reserve. An enzyme immunoassay technique was used to quantify cortisol metabolites and sex hormones from each of 110 fresh wildcat faecal samples collected from walked transects on forest roads within each zone. The number of visitors was recorded as a measure of tourist pressure.

Key results
The general linear model indicated that park zone and faecal progesterone levels were the factors that explained the variation in the faecal glucocorticoid metabolite levels. Cortisol metabolite concentrations were higher in some park zones where tourism intensity was higher (restricted public-use zone). Faecal cortisol metabolite concentrations were more elevated during gestation (spring) and during the young dispersal period (autumn).

Key conclusions
Therefore, we recommend that some zones of park (integral reserve) continue being maintained free of visitor impact and that visitor numbers be specially controlled during the animals’ sensitive periods (gestation) in the zone of restricted public use and in the restricted zone.
Effects of egg oiling on ground-nesting double-crested cormorants at a colony in Lake Ontario: an examination of nest-attendance behaviour
Authors: Taylor Bernard , Fraser Gail S.
Published: May 2013

Context
We assessed the effects of egg oiling on ground-nesting double-crested cormorants (Phalacrocorax auritus) in the context of an emerging management strategy for the largest known cormorant colony on the lower Great Lakes. We designed the present study to answer specific questions in response to concerns raised by stakeholders and members of the public regarding this management technique.

Aims
The aim of the present study was to examine the behavioural response of adult cormorants to egg oiling. Prior work on this issue has focussed on population-response questions rather than the behavioural level. Consequently, detailed observations on how cormorants respond to egg oiling are lacking.

Methods
Using instantaneous and focal observations to measure behaviours, we compared Treatment nests (n = 24, 23) to Control (n = 24) and Sham (handled, but not treated; n = 24) nests. We observed nest attendance, incubation and mate-presence behaviour, and divided observations into pre-chick and entire-season categories for analysis.

Key results
Our study determined that egg oiling does not cause immediate nest desertion by adult birds; Treatment birds incubated their nests as long as did Sham and Control birds. We found no difference among the three groups in the proportion of time a mate was present during incubation for Control and Sham nests in the pre-chick period. We found that the total seasonal duration of nest attendance by Treatment birds was shorter than that for the birds in the other groups.

Conclusions
Both incubation and mate-presence data suggest that egg oiling did not measurably affect the behaviour of adult cormorants in the pre-chick period. Our study also suggests that Treatment birds attended their nest long enough to preclude re-nesting within the breeding season, although this may not apply for regions with longer nesting seasons.

Implications
Our study indicates that egg oiling, administered judiciously, may be an appropriate management technique for ground-nesting cormorants, although management targets must be clearly articulated.