709,868 research outputs found
Endophytic Fungi of Bitter Melon \u3ci\u3e(Momordica Charantia)\u3c/i\u3e in Guangdong Province, China
Endophytic fungi can mutualistically interact with their host plants by deterring herbivores. Overall 1172 endophytic fungal isolates were recovered from roots, stems, leaves, flowers and fruits of bitter melon, Momordica charantia, at five sites in Guangdong Province. These isolates were identified to 25 genera using morphological and molecular characteristics. The endophyte communities at the five sites were similar. Alternaria alternata, Aspergillus spp., Cladosporium spp., Colletotrichum spp., Nigrospora spp., Penicillium spp., Arthrinium spp., Chaetimium spp., Curvularia spp., Fusarium spp., Phoma spp., and Phomopsis spp. were isolated from at least three of the five sites. The coefficient of similarity for endophytes ranged from 60.6% to 83.3% between any two sites. There were significant differences in the species composition of endophytes recovered from different tissues of bitter melon. Fusarium spp. was the most frequent in root and stem samples, Colletotrichum spp. in leaf samples, A. alternata in flower samples, and Cladosporium spp. in fruit samples. The coefficients of similarity for endophytes were between 42.9% and 80.0% from any two tissues. We found that the composition of endophytes of bitter melon was relatively stable across sites, but differed greatly among tissues. We also found that there were fewer insects such as aphids (Homoptera: Aphididae), leafminers (Lepidoptera, Gracillariidae), and cotton leafworms Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) collected from the leaves of bitter melon at the Huadu site compared to those collected at the Yunfu site. Whether this is related to the endophyte communities isolated from different sites requires further research
Descriptions of new genera and species of South African spiders
The present paper contains descriptions of 4 new genera and 62 new species of South African Spiders contained in the Collection of the South African Museum. With the exception of 3 new species of Prodidomidae, all of them belong to the groups Mygalomorphae (Migidce, 1 n. sp.; Ctenizidae, 1 n. gen. and 5 n. spp.; Barychelidae, 2 n. spp.), Cribellatae (Uloboridae, 1 n. gen. and 3 n. spp.; Dictynirlce, 4 n. spp.; Eresidae, 6 n. spp.) , and Ecribellatae Haplogynae (Sicariidae, 19 n. spp.; Dysderidae, 1 n. geu. and 11 n. spp.; Caponiidae, 1 n. gen. and 8 n. spp.)
Efficient unidirectional nanoslit couplers for surface plasmons
Plasmonics is based on surface plasmon polariton (SPP) modes which can be
laterally confined below the diffraction limit, thereby enabling ultracompact
optical components. In order to exploit this potential, the fundamental
bottleneck of poor light-SPP coupling must be overcome. In established SPP
sources (using prism, grating} or nanodefect coupling) incident light is a
source of noise for the SPP, unless the illumination occurs away from the
region of interest, increasing the system size and weakening the SPP intensity.
Back-side illumination of subwavelength apertures in optically thick metal
films eliminates this problem but does not ensure a unique propagation
direction for the SPP. We propose a novel back-side slit-illumination method
based on drilling a periodic array of indentations at one side of the slit. We
demonstrate that the SPP running in the array direction can be suppressed, and
the one propagating in the opposite direction enhanced, providing localized
unidirectional SPP launching.Comment: 13 pages, 4 figure
Mycobiome of the Bat White Nose Syndrome (WNS) Affected Caves and Mines reveals High Diversity of Fungi and Local Adaptation by the Fungal Pathogen Pseudogymnoascus (Geomyces) destructans
The investigations of the bat White Nose Syndrome (WNS) have yet to provide
answers as to how the causative fungus Pseudogymnoascus (Geomyces) destructans
(Pd) first appeared in the Northeast and how a single clone has spread rapidly
in the US and Canada. We aimed to catalogue Pd and all other fungi (mycobiome)
by the culture-dependent (CD) and culture-independent (CI) methods in four
Mines and two Caves from the epicenter of WNS zoonotic. Six hundred sixty-five
fungal isolates were obtained by CD method including the live recovery of Pd.
Seven hundred three nucleotide sequences that met the definition of operational
taxonomic units (OTUs) were recovered by CI methods. Most OTUs belonged to
unidentified clones deposited in the databases as environmental nucleic acid
sequences (ENAS). The core mycobiome of WNS affected sites comprised of 46
species of fungi from 31 genera recovered in culture, and 17 fungal genera and
31 ENAS identified from clone libraries. Fungi such as Arthroderma spp.,
Geomyces spp., Kernia spp., Mortierella spp., Penicillium spp., and
Verticillium spp. were predominant in culture while Ganoderma spp., Geomyces
spp., Mortierella spp., Penicillium spp. and Trichosporon spp. were abundant is
clone libraries. Alpha diversity analyses from CI data revealed that fungal
community structure was highly diverse. However, the true species diversity
remains undetermined due to under sampling. The frequent recovery of Pd
indicated that the pathogen has adapted to WNS-afflicted habitats. Further,
this study supports the hypothesis that Pd is an introduced species. These
findings underscore the need for integrated WNS control measures that target
both bats and the fungal pathogen.Comment: 59 pages, 7figure
Grating-coupled excitation of multiple surface plasmon-polariton waves
The excitation of multiple surface-plasmon-polariton (SPP) waves of different
linear polarization states and phase speeds by a surface-relief grating formed
by a metal and a rugate filter, both of finite thickness, was studied
theoretically, using rigorous coupled-wave-analysis. The incident plane wave
can be either p or s polarized. The excitation of SPP waves is indicated by the
presence of those peaks in the plots of absorbance vs. the incidence angle that
are independent of the thickness of the rugate filter. The absorbance peaks
representing the excitation of s-polarized SPP waves are narrower than those
representing p-polarized SPP waves. Two incident plane waves propagating in
different directions may excite the same SPP wave. A line source could excite
several SPP waves simultaneously
Microbial processes and bacterial populations associated to anaerobic treatment of sulfate-rich wastewater
A pilot-scale (1.2 m3) anaerobic sequencing batch biofilm reactor (ASBBR) containing mineral coal for biomass attachment was fed with sulfate-rich wastewater at increasing sulfate concentrations. Ethanol was used as the main organic source. Tested COD/sulfate ratios were of 1.8 and 1.5 for sulfate loading rates of 0.65–1.90 kgSO42−/cycle (48 h-cycle) or of 1.0 in the trial with 3.0 gSO42− l−1. Sulfate removal efficiencies observed in all trials were as high as 99%. Molecular inventories indicated a shift on the microbial composition and a decrease on species diversity with the increase of sulfate concentration. Beta-proteobacteria species affiliated with Aminomonas spp. and Thermanaerovibrio spp. predominated at 1.0 gSO42− l−1. At higher sulfate concentrations the predominant bacterial group was Delta-proteobacteria mainly Desulfovibrio spp. and Desulfomicrobium spp. at 2.0 gSO42− l−1, whereas Desulfurella spp. and Coprothermobacter spp. predominated at 3.0 gSO42− l−1. These organisms have been commonly associated with sulfate reduction producing acetate, sulfide and sulfur. Methanogenic archaea (Methanosaeta spp.) was found at 1.0 and 2.0 gSO42− l−1. Additionally, a simplified mathematical model was used to infer on metabolic pathways of the biomass involved in sulfate reduction
Tunable THz Surface Plasmon Polariton based on Topological Insulator-Layered Superconductor Hybrid Structure
We theoretically investigate the surface plasmon polariton (SPP) at the
interface between 3D strong topological insulator (TI) and layered
superconductor-magnetic insulator structure. The tunability of SPP through
electronic doping can be enhanced when the magnetic permeability of the layered
structure becomes higher. When the interface is gapped by superconductivity or
perpendicular magnetism, SPP dispersion is further distorted, accompanied by a
shift of group velocity and penetration depth. Such a shift of SPP reaches
maximum when the magnitude of Fermi level approaches the gap value, and may
lead to observable effects. The tunable SPP at the interface between layered
superconductor and magnetism materials in proximity to TI surface may provide
new insight in the detection of Majorana Fermions.Comment: 6 pages, 4 figure
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