1,585 research outputs found
Coupled-channel study of gamma p --> K+ Lambda
A coupled-channel (CC) approach has been developed to investigate kaon
photoproduction on the nucleon. In addition to direct K+ Lambda production, our
CC approach accounts for strangeness production including K+ Lambda final state
interactions with both pi0 p and pi+ n intermediate states. Calculations for
the gamma p --> K+ Lambda reaction have been performed, and compared with the
recent data from SAPHIR, with emphasis on the CC effects. We show that the CC
effects are significant at the level of inducing 20% changes on total cross
sections; thereby, demonstrating the need to include pi N channels to correctly
describe the gamma p --> K+ Lambda reaction.Comment: 12 pages, 6 eps figures, uses elsart.cls, submitted to Phys.Lett.B;
v2: added paragraph in section
Complementary Therapy with Traditional Chinese Medicine for Neonatal Hypoxic Ischemic Encephalopathy
Hypoxic ischemic encephalopathy (HIE) is one of the most significant causes of morbidity, mortality, and lifelong disability in newborns. The diagnosis of neonatal HIE is based on the dysfunction of neurogenic signs and classification according to the Sarnat staging system, which evaluates conscious level, neuromuscular control, complex reflexes, autonomic function, seizures, electroencephalogram readings, and duration of neurologic sign. There is no standard treatment for neonatal HIE, but it is widely accepted that hypothermia therapy is a safe and effective method for treating neonates with HIE. Traditional Chinese medicine (TCM) has recently been used to treat cases of neonatal HIE, especially herbal medicine prescriptions. Acupuncture is a common method used in TCM and is another promising therapy for neonatal HIE due to its demonstrated effective treatment of the disease in animal models. While there is a lack of direct evidence in clinical practice, we have observed acupuncture to be useful in adult HIE and in animal studies; therefore, we believe a clinical trial designed to evaluate the effectiveness of acupuncture in neonatal HIE treatment is worthwhile. Taken together, TCM is a promising technique that can be integrated into the conventional therapies for neonatal HIE
Genetic engineering of plants through manipulation of lignin biosynthesis
The invention pertains to the genetically down regulating a lignin pathway p-coumarate Co-enzyme A ligase (CCL) in trees.https://digitalcommons.mtu.edu/patents/1044/thumbnail.jp
Methods of modifying lignin in plants by transformation with a 4-coumarate coenzyme a ligase nucleic acid
The invention pertains to methods of altering growth, lignin content, coniferyl and sinapyl alcohol units in the lignin structure, disease resistance and cellulose content in plants by transformation with a lignin pathway p-coumarate Co-enzyme A ligase (4CL) nucleic acid.https://digitalcommons.mtu.edu/patents/1058/thumbnail.jp
4-Coumarate co-enzyme a ligase promoter
The present invention provides a Populus 4-coumarate Co-enzyme A ligase gene promoter that directs expression in the xylem of plants. The promoter is used in methods designed to alter lignin content, lignin structure, cellulose content and combinations thereof. The methods comprise operably linking said promoter to heterologous nucleic acid molecules.https://digitalcommons.mtu.edu/patents/1051/thumbnail.jp
Did the S.A.R.S. epidemic weaken the integration of Asian stock markets? Evidence from smooth time-varying cointegration analysis
The purpose of this study is to examine the effect of the Severe
Acute Respiratory Syndrome (S.A.R.S.) epidemic on the long-run
relationship between China and four Asian stock markets. To this
end, we first employ the advanced smooth time-varying cointegration
model to investigate the existence of a time-varying cointegration
relation among these markets and then employ the difference-indifferences
approach to analyse whether or not the S.A.R.S. epidemic
impacted the long-run relation between China and these four markets
during the period 1998–2008, covering 5 years before and after the
S.A.R.S. outbreak. Our results support the existence of a time-varying
cointegration relation in the aggregate stock price indices, and that
the S.A.R.S. epidemic did weaken the long-run relationship between
China and the four markets. Therefore, stockholders and policy makers
should be concerned about the influence of catastrophic epidemic
diseases on the financial integration of stock market in Asia
Differential evolutionary conservation of motif modes in the yeast protein interaction network
BACKGROUND: The importance of a network motif (a recurring interconnected pattern of special topology which is over-represented in a biological network) lies in its position in the hierarchy between the protein molecule and the module in a protein-protein interaction network. Until now, however, the methods available have greatly restricted the scope of research. While they have focused on the analysis in the resolution of a motif topology, they have not been able to distinguish particular motifs of the same topology in a protein-protein interaction network. RESULTS: We have been able to assign the molecular function annotations of Gene Ontology to each protein in the protein-protein interactions of Saccharomyces cerevisiae. For various motif topologies, we have developed an algorithm, enabling us to unveil one million "motif modes", each of which features a unique topological combination of molecular functions. To our surprise, the conservation ratio, i.e., the extent of the evolutionary constraints upon the motif modes of the same motif topology, varies significantly, clearly indicative of distinct differences in the evolutionary constraints upon motifs of the same motif topology. Equally important, for all motif modes, we have found a power-law distribution of the motif counts on each motif mode. We postulate that motif modes may very well represent the evolutionary-conserved topological units of a protein interaction network. CONCLUSION: For the first time, the motifs of a protein interaction network have been investigated beyond the scope of motif topology. The motif modes determined in this study have not only enabled us to differentiate among different evolutionary constraints on motifs of the same topology but have also opened up new avenues through which protein interaction networks can be analyzed
Dynamical coupled-channel model of kaon-hyperon interactions
The pi N --> KY and KY --> KY reactions are studied using a dynamical
coupled-channel model of meson-baryon interactions at energies where the baryon
resonances are strongly excited. The channels included are: pi N, K \Lambda,
and K\Sigma. The resonances considered are: N^* [S_{11}(1650), P_{11}(1710),
P_{13}(1720),D_{13}(1700)]; \Delta^* [S_{31}(1900), P_{31}(1910),
P_{33}(1920)]; \Lambda ^* [S_{01}(1670), P_{01}(1810)] \Sigma^* [P_{11}(1660),
D_{13}(1670)]; and K^*(892). The basic non-resonant \pi N --> KY and KY --> KY
transition potentials are derived from effective Lagrangians using a unitary
transformation method. The dynamical coupled-channel equations are simplified
by parametrizing the pi N -->pi N amplitudes in terms of empirical pi N
partial-wave amplitudes and a phenomenological off-shell function. Two models
have been constructed. Model A is built by fixing all coupling constants and
resonance parameters using SU(3) symmetry, the Particle Data Group values, and
results from a constituent quark model. Model B is obtained by allowing most of
the parameters to vary around the values of model A in fitting the data. Good
fits to the available data for pi^- p to K^0 \Lambda, K^0 \Sigma^0 have been
achieved. The investigated kinematics region in the center-of-mass frame goes
from threshold to 2.5 GeV. The constructed models can be imbedded into
associated dynamical coupled-channel studies of kaon photo- and
electro-production reactions.Comment: 35 pages, 11 Figure
Melanogenesis Inhibitor(s) from Phyla nodiflora
Overexpression of tyrosinase can cause excessive production of melanin and lead to hyperpigmentation disorders, including melasma and freckles. Recently, agents obtained from plants are being used as alternative medicines to downregulate tyrosinase synthesis and decrease melanin production. Phyla nodiflora Greene (Verbenaceae) is used as a folk medicine in Taiwanese for treating and preventing inflammatory diseases such as hepatitis and dermatitis. However, the antimelanogenesis activity and molecular biological mechanism underlying the activity of the methanolic extract of P. nodiflora (PNM) have not been investigated to date. Our results showed that PNM treatment was not cytotoxic and significantly reduced the cellular melanin content and tyrosinase activity in a dose-dependent manner (P<0.05). Further, PNM exhibited a significant antimelanogenesis effect (P<0.05) by reducing the levels of phospho-cAMP response element-binding protein and microphthalmia-associated transcription factor (MITF), inhibiting the synthesis of tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2, and decreasing the cellular melanin content. Moreover, PNM significantly activated the phosphorylation of mitogen-activated protein kinases, including phospho-extracellular signal-regulated kinase, c-Jun N-terminal kinase, and phospho-p38, and inhibited the synthesis of MITF, thus decreasing melanogenesis. These properties suggest that PNM could be used as a clinical and cosmetic skin-whitening agent to cure and/or prevent hyperpigmentation
Genetic copy number variants in sib pairs both affected with schizophrenia
<p>Abstract</p> <p>Background</p> <p>Schizophrenia is a complex disorder with involvement of multiple genes.</p> <p>Methods</p> <p>In this study, genome-wide screening for DNA copy-number variations (CNVs) was conducted for ten pairs, a total of 20 cases, of affected siblings using oligonucleotide array-based CGH.</p> <p>Results</p> <p>We found negative symptoms were significantly more severe (p < 0.05) in the subgroup that harbored more genetic imbalance (n ≧ 13, n = number of CNV-disrupted genes) as compared with the subgroup with fewer CNVs (n ≦ 6), indicating that the degree of genetic imbalance may influence the severity of the negative symptoms of schizophrenia. Four central nervous system (CNS) related genes including CCAAT/enhancer binding protein, delta (<it>CEBPD</it>, 8q11.21), retinoid × receptor, alpha (<it>RXRA</it>, 9q34.2), LIM homeobox protein 5 (<it>LHX5</it>, 12q24.13) and serine/threonine kinase 11 (<it>STK11</it>, 19p13.3) are recurrently (incidence ≧ 16.7%) disrupted by CNVs. Two genes, <it>PVR </it>(poliovirus receptor) and <it>BU678720</it>, are concordantly deleted in one and two, respectively, pairs of co-affected siblings. However, we did not find a significant association of this <it>BU678720 </it>deletion and schizophrenia in a large case-control sample.</p> <p>Conclusions</p> <p>We conclude that the high genetic loading of CNVs may be the underlying cause of negative symptoms of schizophrenia, and the CNS-related genes revealed by this study warrant further investigation.</p
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