Dendrobium moniliforme is a native species of Korea. The flower of this species is composed of a reproductive column and white perianths including petals, sepals and lip, but the base of the column bears reddish purple pigment spots. Anthocyanins are major pigments that contribute flower color in Dendrobium. Three key anthocyanin biosynthetic genes encoding dihydroflavonol 4-reductase (DFR), chalcone synthase (CHS), and flavonoid 3',5'-hydroxylase (F3'5'H) were isolated and analyzed for their expression patterns in floral organs to understand the molecular mechanism underlying flower color development. Quantitative RT-PCR analysis revealed that F3'5'H transcripts were highly accumulated in the base of the column compared with those of perianths, but the other two genes showed no significant difference among the floral organs.Microprojectile bombardment using the white perianths revealed that the transient expression of F3'5'H gene, but not DFR and CHS genes, was sufficient to produce reddish purple colored pigmentation. These results suggest that the lack of colors in perianths of D. moniliforme is at least due to transcriptional control of F3'5'H. The data presented here may improve our understanding of the mechanisms underlying floral color development in D. moniliforme and contribute to advances in orchid biotechnology.
We present our experience on the hypofractionated Gamma Knife radiosurgery (FGKS) for large skull base meningioma as an initial treatment. We retrospectively reviewed 23 patients with large skull base meningioma ≥10 cm3 who underwent FGKS as the initial treatment option. The mean volume of tumors prior to radiosurgery was 21.2±15.63 cm3 (range, 10.09~71.42). The median total margin dose and marginal dose per fraction were 18 Gy (range, 15~20) and 6 Gy (range, 5~6), respectively. Patients underwent three or four fractionations in consecutive days with the same Leksell® frame. The mean follow-up duration was 38 months (range, 17~78). There was no mortality. At the last follow-up, the tumor volume was stationary in 15 patients (65.2%) and had decreased in 8 patients (34.8%). Six patients who had cranial neuropathy at the time of FGKS showed improvement at the last clinical follow-up. Following FGKS, 4 patients (17%) had new cranial neuropathy. The trigeminal neuropathy was the most common and all were transient. The mean Karnofsky Performance Status score at pre-FGKS and the last clinical follow-up was 97.0±10.4 points (median, 100) and 98.6±6.9 (median, 100) points, respectively. FGKS has showed satisfactory tumor control with functional preservation for large skull base meningiomas. Further prospective studies of large cohorts with long term follow-up are required to clarify the efficacy in the tumor control and functional outcome as well as radiation toxicity.
A comprehensive study on the orchid diversity in Penang Hill, Penang, Malaysia was conducted from 2004 to 2008 with the objective to evaluate the presence of orchid species listed by Curtis (J Strait Br R Asiat Soc 25:67-173, 1894) after more than 100 years. A total of 85 species were identified during this study, of which 52 are epiphytic or lithophytic and 33 are terrestrial orchids. This study identified 57 species or 64.8% were the same as those recorded by Curtis (1894), and 78 species or 66.1% of Turner's (Gardens' Bull Singap 47(2):599-620, 1995) checklist of 118 species for the state of Penang including 18 species which were not recorded by Curtis (1894) and the current study but are actually collected from Penang Hill. A comparison table of the current findings against Curtis (1894) and Turner (1995) is provided which shows only 56 species were the same in all three studies. The preferred account for comparison was Curtis' (1894) list as his report was specifically for the areas around Penang Island especially Penang Hill, Georgetown and Ayer Itam areas. Our study reveals that about 50% of Curtis' collection localities have been converted to residential areas and agricultural land, and this probably explains the decreasing numbers of species found in the current study especially for the terrestrial species as epiphytic species have better adaptation capabilities towards environmental
An airborne sensor is developed for remote sensing on an aerial vehicle (UV). The sensor is an optical payload for an eletro-optical/infrared (EO/IR) dual band camera that combines visible and IR imaging capabilities in a compact and lightweight package. It adopts a Ritchey-Chrétien telescope for the common front end optics with several relay optics that divide and deliver EO and IR bands to a charge-coupleddevice (CCD) and an IR detector, respectively. The EO/IR camera for dual bands is mounted on a two-axis gimbal that provides stabilized imaging and precision pointing in both the along and cross-track directions. We first investigate the mechanical deformations, displacements and stress of the EO/IR camera through finite element analysis (FEA) for five cases: three gravitational effects and two thermal conditions. For investigating gravitational effects, one gravitational acceleration (1 g) is given along each of the +x, +y and +z directions. The two thermal conditions are the overall temperature change to 30℃ from 20℃ and the temperature gradient across the primary mirror pupil from -5℃ to +5℃. Optical performance, represented by the modulation transfer function (MTF), is then predicted by integrating the FEA results into optics design/analysis software. This analysis shows the IR channel can sustain imaging performance as good as designed, i.e., MTF 38% at 13 line-pairs-per-mm (lpm), with refocus capability. Similarly, the EO channel can keep the designed performance (MTF 73% at 27.3 lpm) except in the case of the overall temperature change, in which the EO channel experiences slight performance degradation (MTF 16% drop) for 20℃ overall temperate change.
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