3,014 research outputs found
Effect of Total Leaf Numbers on the Growth and Fruit Quality in Muskmelon Plants Showing Leaf Yellowing Symptoms
This study was conducted to evaluate the influence of total leaf
numbers on the growth, net formation of fruits, and occurrence of
leaf yellowing symptoms (LYS) in muskmelon plants. The growth
and development of LYS on muskmelon plants having 25, 30, and
35 fully expanded leaves on the vine were compared to those of the
control plant having 20 leaves. Plant height, leaf area, root fresh
weight, and root dry weight increased as the number of leaves
increased. Plants with 35 leaves showed the greatest plant growth.
Net photosynthetic rate was positively related to increasing leaf
numbers with plants having over 25 leaves showing the greatest
photosynthetic rates. On the other hand, there were no significant
differences in chlorophyll content and root activity among treatments
with different leaf numbers. The ratio of LYS infection was also
greater in plants having 25-30 leaves, than in those having leaf
numbers. Plants with different leaf numbers and LYS infection
showed a variation in fruit quality, although LYS did not
significantly affect fruit quality except net index. The plants having
20 leaves that showed LYS developed fruits that had significantly
smaller flesh (mesocarp) thickness than, the plants having greater numbers of leaves. The higher sugar contents of fruits were found
in the plants having 35 leaves whether they showed LYS (12.1°Bx)
or not (12.5°Bx). Therefore, leaving more than 25 healthy leaves per
plant was recommended for minimizing damage from LYS.OAIID:oai:osos.snu.ac.kr:snu2015-01/104/0000027607/11ADJUST_YN:NEMP_ID:A075898DEPT_CD:517CITE_RATE:0FILENAME:(이희주)effect_of_total_leaf_numbers_on_the_growth_and_fruit_quality_in_muskmelon_plants_showing_leaf_yell··.pdfDEPT_NM:식물생산과학부CONFIRM:
Genomic characterization of Nocardia seriolae strains isolated from diseased fish
Members of the genus Nocardia are widespread in diverse environments; a wide range of Nocardia species are known to cause nocardiosis in several animals, including cat, dog, fish, and humans. Of the pathogenic Nocardia species, N. seriolae is known to cause disease in cultured fish, resulting in major economic loss. We isolated two N. seriolae strains, CK‐14008 and EM15050, from diseased fish and sequenced their genomes using the PacBio sequencing platform. To identify their genomic features, we compared their genomes with those of other Nocardia species. Phylogenetic analysis showed that N. seriolae shares a common ancestor with a putative human pathogenic Nocardia species. Moreover, N. seriolae strains were phylogenetically divided into four clusters according to host fish families. Through genome comparison, we observed that the putative pathogenic Nocardia strains had additional genes for iron acquisition. Dozens of antibiotic resistance genes were detected in the genomes of N. seriolae strains; most of the antibiotics were involved in the inhibition of the biosynthesis of proteins or cell walls. Our results demonstrated the virulence features and antibiotic resistance of fish pathogenic N. seriolae strains at the genomic level. These results may be useful to develop strategies for the prevention of fish nocardiosis.
β-Caryophyllene attenuates dextran sulfate sodium-induced colitis in mice via modulation of gene expression associated mainly with colon inflammation
AbstractWe examined the modulatory activity of β-caryophyllene (CA) and gene expression in colitic colon tissues in a dextran sulfate sodium (DSS)-induced colitis model. Experimental colitis was induced by exposing male BALB/c mice to 5% DSS in drinking water for 7 days. CA (30 or 300mg/kg) was administered orally once a day together with DSS. CA administration attenuated the increases in the disease activity index, colon weight/length ratio, inflammation score, and myeloperoxidase activity in DSS-treated mice. Microarray analysis showed that CA administration regulated the expression in colon tissue of inflammation-related genes including those for cytokines and chemokines (Ccl2, Ccl7, Ccl11, Ifitm3, IL-1β, IL-28, Tnfrsf1b, Tnfrsf12a); acute-phase proteins (S100a8, Saa3, Hp); adhesion molecules (Cd14, Cd55, Cd68, Mmp3, Mmp10, Sema6b, Sema7a, Anax13); and signal regulatory proteins induced by DSS. CA significantly suppressed NF-κB activity, which mediates the expression of a different set of genes. These results suggest that CA attenuates DSS-induced colitis, possibly by modulating the expression of genes associated mainly with colon inflammation through inhibition of DSS-induced NF-κB activity
The Genome Sequence of 'Mycobacterium massiliense' Strain CIP 108297 Suggests the Independent Taxonomic Status of the Mycobacterium abscessus Complex at the Subspecies Level
Members of the Mycabacterium abscessus complex are rapidly growing mycobacteria that are emerging as human pathogens. The M. abscassus complex was previously composed of three species, namely M. abscessus sensu strict, 'M. massiliense', and M. bolletii', In 2011, 'M. massiliense' and 'M. bolletre' were united and reclassified as a single subspecies within M. abscessus: M. abscessus subsp. bolletii. However, the placement of 'M. massiliense' Within the boundary of M. abscessus subsp. balletii remains highly controversial with regard to clinical aspects. In this study, we revisited the taxonomic status of members of the M. abscessus complex based on comparative analysis of he whole-genome sequences of 53 strains, The genome sequence of the previous type strain of 'Mycobacterium massiliense' (CIP 108297) was determined using next-generation sequencing. The genome tree based on average nucleotide identity (AN I) values supported the differentiation of M. bolletii' and M. massiliense' at the subspecies level. The genome tree also clearly illustrated that 'M. bolletil' and 'M. massiliense' form a distinct phylogenetic clade within the radiation of the M. abscessus complex. The genomic distances observed in this study suggest that the current M. abscessus subsp. bolletii taxon should be divided into two subspecies, M. abscessus subsp. massiliense subsp. nov. and M. abscessus subsp. bolletii, to correspondingly accommodate the previously known 'M. assiliense' and 'M. bolletii' strains.
Directing lineage specification of human mesenchymal stem cells by decoupling electrical stimulation and physical patterning on unmodified graphene
The organization and composition of the extracellular matrix (ECM) have been
shown to impact the propagation of electrical signals in multiple tissue
types. To date, many studies with electroactive biomaterial substrates have
relied upon passive electrical stimulation of the ionic media to affect cell
behavior. However, development of cell culture systems in which stimulation
can be directly applied to the material – thereby isolating the signal to the
cell-material interface and cell–cell contracts – would provide a more
physiologically-relevant paradigm for investigating how electrical cues
modulate lineage-specific stem cell differentiation. In the present study, we
have employed unmodified, directly-stimulated, (un)patterned graphene as a
cell culture substrate to investigate how extrinsic electrical cycling
influences the differentiation of naïve human mesenchymal stem cells (hMSCs)
without the bias of exogenous biochemicals. We first demonstrated that cyclic
stimulation does not deteriorate the cell culture media or result in cytotoxic
pH, which are critical experiments for correct interpretation of changes in
cell behavior. We then measured how the expression of osteogenic and
neurogenic lineage-specific markers were altered simply by exposure to
electrical stimulation and/or physical patterns. Expression of the early
osteogenic transcription factor RUNX2 was increased by electrical stimulation
on all graphene substrates, but the mature marker osteopontin was only
modulated when stimulation was combined with physical patterns. In contrast,
the expression of the neurogenic markers MAP2 and β3-tubulin were enhanced in
all electrical stimulation conditions, and were less responsive to the
presence of patterns. These data indicate that specific combinations of non-
biological inputs – material type, electrical stimulation, physical patterns –
can regulate hMSC lineage specification. This study represents a substantial
step in understanding how the interplay of electrophysical stimuli regulate
stem cell behavior and helps to clarify the potential for graphene substrates
in tissue engineering applications
Application of the Whole Genome-Based Bacterial Identification System, TrueBac ID, Using Clinical Isolates That Were Not Identified With Three Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) Systems
Background: Next-generation sequencing is increasingly used for taxonomic identification of pathogenic bacterial isolates. We evaluated the performance of a newly introduced whole genome-based bacterial identification system, TrueBac ID (ChunLab Inc., Seoul, Korea), using clinical isolates that were not identified by three matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems and 16S rRNA gene sequencing. Methods: Thirty-six bacterial isolates were selected from a university-affiliated hospital and a commercial clinical laboratory. Species was identified by three MALDI-TOF MS systems: Bruker Biotyper MS (Bruker Daltonics, Billerica, MA, USA), VITEK MS (bioMerieux, Marcy l'Etoile, France), and ASTA MicrolDSys (ASTA Inc., Suwon, Korea). Whole genome sequencing was conducted using the Illumina MiSeq system (Illumina, San Diego, CA, USA), and genome-based identification was performed using the TrueBac ID cloud system (www.truebacid.com ). Results: TrueBac ID assigned 94% (34/36) of the isolates to known (N=25) or novel (N=4) species, genomospecies (N=3), or species group (N=2). The remaining two were identified at the genus level. Conclusions: TrueBac ID successfully identified the majority of isolates that MALDI-TOF MS failed to identify. Genome-based identification can be a useful tool in clinical laboratories, with its superior accuracy and database-driven operations.
Flora of Vascular Plants in Ridgelines in the Palgongsa Procincial Park, Korea
AbstractWe investigated and analyzed the flora of vascular plants around ridgelines in the Palgongsan Provincial Park to suggest fundamental data for establishing preservation plans of them. The flora of vascular plants around ridgelines was a total of 587 taxa including 102 familiies, 314 genera, 518 species, 58 varieties, 7 forma, and 4 subspecies. Rare plants designated by Korea Forest Service were 27 taxa including Semiquilegia mandshurica and Aristolochia manshuriensis. Endemic plants were 15 taxa including Clematis trichotoma and Carex okamotoi. Floristic special plants were a total of 100 taxa including all five classes. Naturalized plants were 13 taxa including Phytolacca Americana, ambrosia, and Taraxacum officinale
Quantitative agreement of Dzyaloshinskii-Moriya interactions for domain-wall motion and spin-wave propagation
The magnetic exchange interaction is the one of the key factors governing the
basic characteristics of magnetic systems. Unlike the symmetric nature of the
Heisenberg exchange interaction, the interfacial Dzyaloshinskii-Moriya
interaction (DMI) generates an antisymmetric exchange interaction which offers
challenging opportunities in spintronics with intriguing antisymmetric
phenomena. The role of the DMI, however, is still being debated, largely
because distinct strengths of DMI have been measured for different magnetic
objects, particularly chiral magnetic domain walls (DWs) and non-reciprocal
spin waves (SWs). In this paper, we show that, after careful data analysis,
both the DWs and SWs experience the same strength of DMI. This was confirmed by
spin-torque efficiency measurement for the DWs, and Brillouin light scattering
measurement for the SWs. This observation, therefore, indicates the unique role
of the DMI on the magnetic DW and SW dynamics and also guarantees the
compatibility of several DMI-measurement schemes recently proposed.Comment: 24 pages, 5 figure
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