Canopy CO2 concentrations and Crassulacean acid metabolism in Hoya carnosa in a subtropical rain forest in Taiwan: consideration of CO2 avallability and the evolution of CAM in epiphytes

The potential importance of CO2 derived from host tree respiration at night as a substrate for night time CO2 uptake during CAM was investigated in the subtropical and tropical epiphytic vine Hoya carnosa in a subtropical rainforest in north-eastern Taiwan. Individuals were examined within the canopies of host trees in open, exposed situations, as well as in dense forests. Although night time CO2 concentrations were higher near the epiphytic vines at night, relative to those measured during the day, presumably the result Of CO2 added to the canopy air by the host tree, no evidence for substantial use of this CO2 was found. In particular, stable carbon isotope ratios of H. carnosa were not substantially lower than those of many other CAM plants, as would be expected if host-respired CO2 were an important source Of CO2 for these CAM epiphytes. Furthermore, laboratory measurements of diel CO2 exchange revealed a substantial contribution of daytime CO2 uptake in these vines, which should also result in lower carbon isotope values than those characteristic of a CAM plant lacking daytime CO2 uptake. Overall, we found that host-respired CO2 does not contribute substantially to the carbon budget of this epiphytic CAM plant. This finding does not support the hypothesis that CAM may have evolved in tropical epiphytes in response to diel changes in the CO2 concentrations within the host tree canopy

Crystal structure of Cu-Sn-In alloys around the {\eta} phase field studied by neutron diffraction

The study of the Cu-Sn-In ternary system has become of great importance in recent years, due to new environmental regulations forcing to eliminate the use of Pb in bonding technologies for electronic devices. A key relevant issue concerns the intermetallic phases which grow in the bonding zone and are determining in their quality and performance. In this work, we focus in the {\eta}-phase (Cu2In or Cu6Sn5) that exists in both end binaries and as a ternary phase. We present a neutron diffraction study of the constitution and crystallography of a series of alloys around the 60 at.% Cu composition, and with In contents ranging from 0 to 25 at.%, quenched from 300\degreeC. The alloys were characterized by scanning electron microscopy, probe microanalysis and high-resolution neutron diffraction. The Rietveld refinement of neutron diffraction data allowed to improve the currently available model for site occupancies in the hexagonal {\eta}-phase in the binary Cu-Sn as well as in ternary alloys. For the first time, structural data is reported in the ternary Cu-Sn-In {\eta}-phase as a function of composition, information that is of fundamental technological importance as well as valuable input data for ongoing modelisations of the ternary phase diagram.Comment: 8 pages, 10 figure

Understorey plant community and light availability in conifer plantations and natural hardwood forests in Taiwan

Questions: What are the effects of replacing mixed species natural forests with Cryptomeria japonica plantations on understorey plant functional and species diversity? What is the role of the understorey light environment in determining understorey diversity and community in the two types of forest? Location: Subtropical northeast Taiwan. Methods: We examined light environments using hemispherical photography, and diversity and composition of understorey plants of a 35‐yr C. japonica plantation and an adjacent natural hardwood forest. Results: Understorey plant species richness was similar in the two forests, but the communities were different; only 18 of the 91 recorded understorey plant species occurred in both forests. Relative abundance of plants among different functional groups differed between the two forests. Relative numbers of shade‐tolerant and shade‐intolerant seedling individuals were also different between the two forest types with only one shade‐intolerant seedling in the plantation compared to 23 seedlings belonging to two species in the natural forest. In the natural forest 11 species of tree seedling were found, while in the plantation only five were found, and the seedling density was only one third of that in the natural forest. Across plots in both forests, understorey plant richness and diversity were negatively correlated with direct sunlight but not indirect sunlight, possibly because direct light plays a more important role in understorey plant growth. Conclusions: We report lower species and functional diversity and higher light availability in a natural hardwood forest than an adjacent 30‐yr C. japonica plantation, possibly due to the increased dominance of shade‐intolerant species associated with higher light availability. To maintain plant diversity, management efforts must be made to prevent localized losses of shade‐adapted understorey plants

Detection of race 1 strains of Ralstonia solanacearum in field samples in Taiwan using a BIO-PCR method

Bacterial wilt caused by race 1 strains of Ralstonia solanacearum is endemic on tomato produced in diverse agro-ecosystems in Taiwan. Using a new BIO-PCR protocol developed in this study, R. solanacearum was detected in soil, weed, and water samples collected from eight fields with different disease histories and cropping systems located in major tomato production areas. The sensitivity of the BIO-PCR was 1.9 CFU ml(-1) and 17 CFU g(-1) of soil for pure suspension and infested soil, respectively. The positive detection frequency of the BIO-PCR method was 66.6, 39.6, 23.1, and 31.8% for all tested samples of soil, weed rhizosphere soil, weed root, and water, respectively, and was higher than plating on MSM-1 medium. Detection of R. solanacearum from field soil indicated that spatial distribution of the pathogen in the field was not even regardless of the presence or absence of the disease and the different agro-ecosystems where the sampled fields were located, and the degree of unevenness was higher when tomato was absent from the field. Weed rhizosphere soils could be good sampling targets to monitor the pathogen in the field, because a higher positive detection proportion and population of R. solanacearum were found in the rhizosphere rather than the root of the collected weed samples. Symptomless weeds and contaminated irrigation, standing, or drainage waters were found to be important for the over-season survival and dissemination of R. solanacearum

A single amino acid substitution in PthA of Xanthomonas axonopodis pv. citri altering canker formation on grapefruit leaves

The typical citrus canker lesions produced by Xanthomonas axonopodis pv. citri are erumpent, callus-like, with water-soaked margins. Three novel atypical symptom-producing variants of X. axonopodis pv. citri were described recently in Taiwan. Only the variant designated as A(f) type produces typical erumpent canker lesions on Mexican lime (Citrus aurantifolia) but induces flat necrotic with water-soaked margin lesions on grapefruit leaves (C. paradisi). Two homologous pthA were cloned and characterized from strains XW19 (a typical canker lesion producing strain) and XW47 (a strain of A(f) type). The pthA homolog from XW19 was transformed into XW47. The transformant of XW47 induced typical erumpent canker lesions on grapefruit leaves. Sequence analyses of transformants XW19 and XW47 revealed over 99% homology in nucleotide and deduced amino acid sequences compared with pthA homologs deposited in GenBank. The amino acid residues located at positions 49, 286, 742 and 767 of PthA were different between XW47 and XW19. The PthA mutants with a single amino acid substitution at each of these four positions were constructed by site-directed mutagenesis. Modified PthA (S286P) from XW47 in transformant 47SP induced erumpent canker lesions on grapefruit leaves, whereas another modified PthA (P286S) from XW19 in transformant 47PS only induced flat necrotic lesions. These results suggested that a single amino acid substitution from either serine to proline or proline to serine at position 286 of PthA can alter canker formation by X. axonopodis pv. citri on grapefruit leaves

Surgical Treatment of Kawasaki Disease with Intestinal Pseudo-obstruction

A 5-year-old boy suffering from abdominal pain accompanied by a fever of up to 39.5 degrees C for 2 days was admitted to the hospital. Although Flomoxef was administered following admission, the boy's fever persisted and abdominal distension gradually worsened. On the 4th day, dry lips, red eyes and a strawberry tongue were noted. An echocardiogram revealed pericoronary enhancement with mild mitral valve regurgitation and a small degree of pericardial effusion, characteristics compatible with Kawasaki disease. Although intravenous immunoglobulin was administered, the fever and abdominal distension persisted. On the 8th day, a pediatric surgeon was consulted and an exploratory laparotomy was arranged. During the operation, intestinal pseudo-obstruction and fibrin coatings around the intestine near the splenic flexure were found. A colostomy was performed for decompression of the dilated bowel and a biopsy of the lymph node surrounding the splenic flexure was taken. The fever subsided dramatically after decompression of the bowel and the recovery course was uneventful. The pathologic report revealed necrotic lymphadenitis. We report this rare case and review the literature

How to compare arc-annotated sequences: The alignment hierarchy

International audienceWe describe a new unifying framework to express comparison of arc-annotated sequences, which we call alignment of arc-annotated sequences. We first prove that this framework encompasses main existing models, which allows us to deduce complexity results for several cases from the literature. We also show that this framework gives rise to new relevant problems that have not been studied yet. We provide a thorough analysis of these novel cases by proposing two polynomial time algorithms and an NP-completeness proof. This leads to an almost exhaustive study of alignment of arc-annotated sequences

A high performance dye-sensitized solar cell with a novel nanocomposite film of PtNP/MWCNT on the counter electrode

An imide-functionalized material, poly(oxyethylene)-segmented polymer, was synthesized from the reaction of poly(oxyethylene) diamine of 2000 g mol(-1) M(w) and 4,4'-oxydiphthalic anhydride and used to disperse hybrid nanomaterials of platinum nanoparticles and multi-wall carbon nanotubes (PtNP/MWCNT). The composite material was spin-coated into film and further prepared as the counter electrode (PtNP/MWCNT-CE) for a dye-sensitized solar cell (DSSC). The short-circuit current density (J(SC)) and power-conversion efficiency (eta) of the DSSC with PtNP/MWCNT-CE were found to be 18.01 +/- 0.91 mA cm(-2) and 8.00 +/- 0.23%, respectively, while the corresponding values were 14.62 +/- 0.19 mA cm(-2) and 6.92 +/- 0.07% for a DSSC with a bare platinum counter electrode (Pt-CE). The presence and distribution of PtNP/MWCNT on the CE were characterized by using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The attachment of PtNPs on MWCNTs was observed by transmission electron microscopy (TEM). Cyclic voltammetry (CV), incident-photo-to-current efficiency (IPCE) and electrochemical impedance spectra (EIS) were correlated to explain the efficacy of this nanocomposite system