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1.
Ronald J. Prokopy Ratana Poramarcom Manon Sutantawong Ranu Dokmaihom Jorge Hendrichs 《Journal of Insect Behavior》1996,9(1):133-142
Oriental fruit flies,Bactrocera dorsalis, cultured in the laboratory for six generations, were released when 12–14 days old in an orchard of nonfruiting host trees that were furnished with either food and water, nonpunctured host fruit, punctured host fruit, or no resources. Nearly all flies of both sexes, all sexual behavior of males, and all mating pairs were observed on trees with fruit. Moreover, on trees with fruit, nearly all flies of both sexes, nearly all sexual behavior of males, and nearly all mating pairs occurred on the fruit itself rather than on the foliage or branches. In a subsequent test, both sexes were found to be strongly attracted to the odor of host fruit. For a polyphagous species of a tropical tephritid, these findings are the first to show a high level of male aggregation and a high amount of male sexual behavior on the fruit of host trees. Findings are discussed in relation to current knowledge of tephritid mating behavior. An additional quality-control test for laboratory cultured males used in the sterile insect technique of fly management is recommended. 相似文献
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Prasad A Naskar R Dubey R Raha D Ahmed MF 《Indian journal of experimental biology》2006,44(2):163-164
Effect of prolonged administration of substance P on the plasma cortisol level in the albino rats has been investigated. An inhibitory impact on intact individuals and a stimulatory effect in pharmacologically annulled rats has been observed. It is concluded that in normal conditions substance P presumably acts as a preventive agent for any excess secretion of cortisol while during stress or disturbed HPA or RAS conditions, it stimulates the secretion of cortisol. An intraglandular modulatory role of substance P has been suggested. 相似文献
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Levels,Sources, and Toxic Potential of Polycyclic Aromatic Hydrocarbons in Urban Soil of Delhi,India
This study was done to determine the concentration of PAHs in urban soil of Delhi (India). Surface top soil (up to 10 cm depth) samples were collected from four different sampling sites including industrial, roadside, residential, and agricultural areas of Delhi and 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) were evaluated. Total PAH concentrations at industrial, roadside, residential, and agricultural sites were 11.46 ± 8.39, 6.96 ± 4.82, 2.12 ± 1.12, and 1.55 ± 1.07 mg/kg (dry weight), respectively, with 3–7 times greater concentrations in industrial and roadside soils than that in residential and agricultural soils. The PAH pattern was dominated by 4- and 5-ring PAHs (contributing >50% to the total PAHs) at industrial and roadside sites with greater concentration of fluoranthene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]anthracene, benzo[ghi]perylene, and pyrene, whereas, residential and agricultural sites showed a predominance of low molecular weight 2- and 3-ring PAHs (fluoranthene, acenaphthene, naphthalene, chrysene, and anthracene). Isomeric pair ratios suggested biomass combustion and fossil fuel emissions as the main sources of PAHs. The toxic equivalency factors (TEFs) showed that carcinogenic potency (benzo[a]pyrene-equivalent concentration (B[a]Peq) of PAH load in industrial and roadside soils was ~10 and ~6 times greater than the agricultural soil. 相似文献
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Peristalsis, the coordinated contraction—relaxation of the muscles of the stomach is important for normal gastric motility and is impaired in motility disorders. Coordinated electrical depolarizations that originate and propagate within a network of interconnected layers of interstitial cells of Cajal (ICC) and smooth muscle (SM) cells of the stomach wall as a slow-wave, underly peristalsis. Normally, the gastric slow-wave oscillates with a single period and uniform rostrocaudal lag, exhibiting network entrainment. Understanding of the integrative role of neurotransmission and intercellular coupling in the propagation of an entrained gastric slow-wave, important for understanding motility disorders, however, remains incomplete. Using a computational framework constituted of a novel gastric motility network (GMN) model we address the hypothesis that engaging biological oscillators (i.e., ICCs) by constitutive gap junction coupling mechanisms and enteric neural innervation activated signals can confer a robust entrained gastric slow-wave. We demonstrate that while a decreasing enteric neural innervation gradient that modulates the intracellular IP3 concentration in the ICCs can guide the aboral slow-wave propagation essential for peristalsis, engaging ICCs by recruiting the exchange of second messengers (inositol trisphosphate (IP3) and Ca2+) ensures a robust entrained longitudinal slow-wave, even in the presence of biological variability in electrical coupling strengths. Our GMN with the distinct intercellular coupling in conjunction with the intracellular feedback pathways and a rostrocaudal enteric neural innervation gradient allows gastric slow waves to oscillate with a moderate range of frequencies and to propagate with a broad range of velocities, thus preventing decoupling observed in motility disorders. Overall, the findings provide a mechanistic explanation for the emergence of decoupled slow waves associated with motility impairments of the stomach, offer directions for future experiments and theoretical work, and can potentially aid in the design of new interventional pharmacological and neuromodulation device treatments for addressing gastric motility disorders. 相似文献
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Dongwei Hui Keshava N. Kumar Julie R. Mach Ashik Srinivasan Ranu Pal Xiaodong Bao Abdulbaki Agbas Georg H?fner Klaus T. Wanner Elias K. Michaelis 《The Journal of biological chemistry》2009,284(4):2245-2257
The cloning and characterization of the gene for the fourth subunit of a
glutamate-binding protein complex in rat brain synaptic membranes are
described. The cloned rat brain cDNA contained two open reading frames (ORFs)
encoding 8.9- (PRO1) and 9.5-kDa (PRO2) proteins. The cDNA sequence matched
contiguous genomic DNA sequences in rat chromosome 17. Both ORFs were
expressed within the structure of a single brain mRNA and antibodies against
unique sequences in PRO1- and PRO2-labeled brain neurons in situ,
indicative of bicistronic gene expression. Dicistronic vectors in which ORF1
and ORF2 were substituted by either two different fluorescent proteins or two
luciferases indicated concurrent, yet independent translation of the two ORFs.
Transfection with noncapped mRNA led to cap-independent translation of only
ORF2 through an internal ribosome entry sequence preceding ORF2. In
vitro or cell expression of the cloned cDNA led to the formation of
multimeric protein complexes containing both PRO1 and PRO2. These complexes
had low affinity
(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine
(MK-801)-sensitive phencyclidine-binding sites. Overexpression of PRO1 and
PRO2 in CHO cells, but not neuroblastoma cells, caused cell death within
24–48 h. The cytotoxicity was blocked by concurrent treatment with
MK-801 or by two tetrahydroisoquinolines that bind to phencyclidine sites in
neuronal membranes. Co-expression of two of the other subunits of the protein
complex together with PRO1/PRO2 abrogated the cytotoxic effect without
altering PRO1/PRO2 protein levels. Thus, this rare mammalian bicistronic gene
coded for two tightly interacting brain proteins forming a low affinity
phencyclidine-binding entity in a synaptic membrane complex.A complex of four proteins purified from brain synaptic membranes was shown
to have recognition sites for l-glutamate,
N-methyl-d-aspartate
(NMDA),4 and other
ligands characteristic of NMDA receptors in brain, including binding sites for
the co-agonist glycine, the modulator spermine, the competitive antagonist
(+)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP), and the ion
channel inhibitors thienylcyclohexylpiperidine (TCP) and
(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine
(MK-801) (1,
2). Reconstitution of the
purified complex into planar lipid bilayer membranes leads to the formation of
channels with four ion conductance levels upon activation by glutamate or NMDA
in the presence of glycine (3).
These conductances differ from either the predominant NMDA-activated
receptor-ion channels of brain neurons or those formed by reconstitution of
the NMDA receptor subunits (4),
but are similar to those described for ion channels in rat spinal cord motor
neurons (5).The genes for three of the proteins in this complex have been cloned and
expressed in heterologous cells
(6–10).
The gene GRINA for the glutamate-binding protein (GBP) subunit was
identified as part of a “learning and memory” module of genes
expressed in the entorhinal cortex of the mammalian brain
(11), and as the gene
responsible for mental retardation and epilepsy in infants with a gene
duplication in chromosome 8q24.3
(12). Expression of
GRINA in heterologous cells leads to activation of mitogen-activated
protein kinases (13),
i.e. it may be involved in signal transduction in neurons. Because of
the potential role of GBP and of the associated membrane complex in cell
signaling, there is a need to fully characterize all components of the complex
and reconstitute the intact complex in cells lacking in its expression. The
genes for two other components of the complex have been cloned, those for the
glycine-binding and CPP-binding proteins. But the gene for the fourth subunit
has not yet been cloned.The fourth protein of the complex was identified on SDS-PAGE as an
∼40-kDa protein. To complete the characterization of this complex of
proteins, the cDNA for the fourth subunit was cloned, and a corresponding
genomic sequence in rat genome was identified. The presence of two open
reading frames (ORFs) in the cloned cDNA, the expression of both ORFs in a
single mRNA in brain, and the translation in brain of the two proteins coded
by the cDNA, led to the investigation of the mechanism of translation of both
ORFs. Translation of both ORFs through an internal ribosome entry sequence
(IRES) was identified, as was the need for the co-expression of the two
proteins to create a functional protein, a phencyclidine-binding protein. 相似文献
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Tourette's syndrome (TS) is a neurodevelopmental disorder characterized by the presence of chronic vocal and motor tics. Tics are sudden, highly stereotyped, movements that can be simple or complex in appearance. Since patients with TS have difficulties preventing unwanted movements, one might expect that their ability to voluntarily control goal-directed movements would be similarly poor. Indeed, it has been suggested that TS sufferers are impaired at inhibiting reflexively triggered movements and in rapidly selecting or switching between different motor sets. This idea is consistent with current views on the neurological basis of TS that posit a dysfunction of the neural circuits linking the frontal lobes and the striatum. These circuits are known to be involved in the voluntary control of action. By using an oculomotor switching task, we show for the first time that young people with TS exhibit paradoxically greater levels of cognitive control over their movements than their age-matched controls. This finding is consistent with an increased need to monitor and control movements and may indicate a subcortical locus for the triggering of tics. It also suggests that the constant need to suppress tics could have resulted in an enhancement of the executive processes involved in inhibitory control. 相似文献
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Pradeep K. Agarwal Rajinder S. Ranu 《In vitro cellular & developmental biology. Plant》2000,36(5):392-397
Summary The in vitro plant regeneration potential of vegetatively propagated geraniums (Pelargonium x hortorum) has been investigated. Using various combinations of growth regulators and a choice of different explants, a regeneration
protocol has been developed to raise in vitro plantlets from young petiole and leaf explants from three different cultivars of geraniums. In all three cultivars, very
young petiole explants exhibited a higher regeneration potential as compared with leaf explants. Regeneration efficiencies
were found to be highly dependent on the cultivar, with cv. Samba showing the highest regeneration potential, followed by
cvs. Yours Truly and then Sincerity. Samba also showed the highest number of shoots from both the petiole [57 shoot buds per
petiole explant in the presence of 3 μM zeatin and 1 μM indole-3-acetic acid (IAA) and leaf explants (43 shoots per leaf explant with 10 μM zeatin and 2 μM IAA). Shoot buds transferred to Murashige and Skoog (MS) medium supplemented with 0.44 μM N6-benzyladenine and 0.11 μM IAA grew vigorously and attained 1–2 cm in length in 3–4 wk. These shoots rooted with 100% efficiency on MS basal medium,
and plants developed that showed normal growth and flowering under greenhouse conditions. 相似文献