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851.
Background
In this paper we present a novel scene retargeting technique to reduce the visual scene while maintaining the size of the key features. The algorithm is scalable to implementation onto portable devices, and thus, has potential for augmented reality systems to provide visual support for those with tunnel vision. We therefore test the efficacy of our algorithm on shrinking the visual scene into the remaining field of view for those patients. 相似文献852.
Downy mildew (Peronospora plantaginis) caused two different types of infection in the floral parts of isabgol (Plantago ovata). Systemic infection resulted in long spikes bearing weak and sterile florets, which later turned black due to saprophytic
growth. Localised infection produced various symptoms ranging between normal flower opening and failure to bloom. Different
parts of infected flowers such as sepal, petal, filament and anther were reduced in size compared to healthy flowers. However,
gynoecium was elongated in localised infection. P. plantaginis induced gradual sterility of isabgol flowers. Androecium was affected more than the gynoecium was. Pollen number, pollen
viability and germination reduced drastically due to localised infection. On the contrary, there were no significant differences
between healthy and locally infected flowers in terms of stigma receptivity. In systemically infected spikes, bud development
was arrested leading to sterility. When localised disease severity was high, secondary systemic infection caused similar symptoms.
Microscopic observations showed presence of the pathogen in different parts of the flowers. Downy mildew adversely affected
seed yield and quality; producing seeds, which were smaller and lighter than the healthy ones and later, became black. Seed
yield was reduced by as much as 73.45 percent. Husk content per unit seed mass increased relatively as the total surface area
of infected seeds increased. 相似文献
853.
854.
855.
<Emphasis Type="Italic">Daphnia galeata</Emphasis> in the deep hypolimnion: spatial differentiation of a “typical epilimnetic” species 总被引:1,自引:1,他引:1
One of the most serious threats to tropical mangrove ecosystems caused by shrimp farming activities is the poor management
of pond waste materials. We hypothesise that mangroves can tolerate chemical residues discharged from shrimp farms and can
be used as biofilters, but the capability of mangroves to cope with solid sediments dredged from shrimp ponds is limited.
Our study in Pak Phanang, Thailand, confirmed that the excess sediments discharged from nearby shrimp ponds reduced mangrove
growth rates and increased mortality rates. A series of transformed multi-temporal satellite images was used in combination
with the field data to support this claim. In addition, a comparison between four dominant mangrove species revealed that
Avicennia marina could tolerate sedimentation rates of >6 cm year−1, while Bruguiera cylindrica tolerated sedimentation rates of 5 cm year−1 (total sediment depth = 25 cm) before dying, while Excoecaria agallocha and Lumnitzera racemosa performed intermediate. This outcome implied that in our situation A. marina and to lesser extent E. agallocha and L. racemosa could be more effective as biofilters than B. cylindrica, as they may survive the sedimentation longer in the disposal areas. Further studies on the impact of sedimentation and chemical
pollution of shrimp farm wastes on mangrove mortality and growth are required. 相似文献
856.
Wen Liu Xuesen Chen Guanjun Liu Qing Liang Tianming He Jianrong Feng 《Plant Cell, Tissue and Organ Culture》2007,88(3):289-299
Embryo rescue technique was used successfully to produce interspecific hybrids by crossing peach (P. persica) as a female parent with apricot (P. armeniaca) and plum (P. salicica). In those crosses that had ‘Yuhualu’ or ‘Zhonghuashoutao’ as female parents, hybrid embryos aborted from the 7th or 8th
week after pollination mainly due to post-pollination incompatibility. An embryo rescue protocol was established to rescue
such embryos and recover hybrid plants. Modified half-strength MS medium containing 4 mg l−1 6-BA and 0.5 mg l−1 IBA produced up to 90% germination in the embryos. Modified MS medium with 1.0 mg l−1 6-BA and 1.0 mg l−1 IBA gave the highest bud induction and multiplication whereas modified MS medium containing 0.5 mg l−1 IAA and 0.2 mg l−1 NAA gave the best rooting percentage. All the hybrids obtained using this embryo rescue technique were verified using simple
sequence repeat (SSR) markers. A series of pollen treatments were carried out to partially overcome pre-pollination incompatibility,
and it was found accidentally that pollen treatment with electrostatic field not only improved pollen germination but also
increased the multiplication coefficient of embryo-induced shoots. 相似文献
857.
High production of laccase by a new basidiomycete, <Emphasis Type="Italic">Trametes</Emphasis> sp 总被引:1,自引:0,他引:1
A new basidiomycete, Trametes sp. 420, produced laccase at 6,810 U l−1 (268 mg, 25.4 U mg−1 protein for guaiacol) in glucose medium and 7,870 U l−1 (310 mg) in cellobiose medium with induction by 0.5 mM Cu2+ and 6 mM o-toluidine. Laccase isozyme E (LacE) was the sole laccase in the fermentation products. It was stable at pH 5–9 and below
70°C over 30 min. The K
m values of LacE for four substrates (guaiacol ABTS, 2,6-dimethoxyphenol and syringaldazine) varied from 5 to 245 μM. The activity
of LacE was strongly inhibited by NaN3 but not by EDTA or dimethylsulfoxide. LacE at 0.5 U l−1 could decolorize industrial dyes. The open reading frame of the lacE gene was 2,130 bp and was interrupted by 10 introns. It displayed a high homology to laccases from other fungi.
Pingui Tong and Yuzhi Hong contributed equally to the study 相似文献
858.
Various approaches have been developed to define conservation units for plant and animal species. In this study we combined
nuclear microsatellites (from a previous published study) and chloroplast microsatellites (assessed in the present study),
leaf and seed morphology traits and abiotic variables (climate and soil) to define evolutionary significant units (ESU) of
Santalum austrocaledonicum, a tree species growing in New Caledonia. Results for chloroplast microsatellites showed that the total population heterozygosity
was␣high, (H
cp = 0.84) but varied between islands. Differentiation was strong in the total population (F
stcp = 0.66) but also within the main island Grande Terre (F
stcp = 0.73) and within Iles Loyauté (F
stcp = 0.52), highlighting a limited gene flow between populations. These results confirmed those obtained with nuclear microsatellites.
The cluster analysis on molecular markers discriminated two main groups constituted by the populations of Grande Terre and
the populations of Iles Loyauté. A principal component analysis of leaf and seed morphology traits singled out the populations
of Iles Loyauté and the western populations of Grande Terre. Quantitative genetic analyses showed that the variation between
populations was under genetic control (broad sense heritability close to 80%). A high correlation between rainfall and morphological
traits suggested an impact of climate on this variation. The integration of these results allows to define two ESUs, one corresponding
to Grande Terre and Ile des Pins and the other the Iles Loyauté archipelago. This study stresses the need to restore some
populations of Grande Terre that are currently threatened by their small size. 相似文献
859.
Yin Li Zhiqiang Liu Fengjie Cui Yingying Xu Hui Zhao 《World journal of microbiology & biotechnology》2007,23(6):837-843
A new strain of Penicillium sp. ZH-30 that produces xylanase was isolated from soil. According to the morphology and comparison of internal transcribed
spacer (ITS) rDNA gene sequence, the strain Penicillium sp. ZH-30 was identified as a strain of Penicillium oxalicum. When xylan or wheat bran was used as substrate at 30°C for 3 days under submerged cultivation, xylanase production was 5.3
and 13.3 U ml−1, respectively. The temperature and pH for optimum activity were 50°C and 5.0–6.0, respectively. 相似文献
860.
Climate and species affect fine root production with long-term fertilization in acidic tussock tundra near Toolik Lake,Alaska 总被引:3,自引:0,他引:3
Long-term fertilization of acidic tussock tundra has led to changes in plant species composition, increases in aboveground
production and biomass and substantial losses of soil organic carbon (SOC). Root litter is an important input to SOC pools,
although little is known about fine root demography in tussock tundra. In this study, we examined the response of fine root
production and live standing fine root biomass to short- and long-term fertilization, as changes in fine root demography may
contribute to observed declines in SOC. Live standing fine root biomass increased with long-term fertilization, while fine
root production declined, reflecting replacement of the annual fine root system of Eriophorum vaginatum, with the long-lived fine roots of Betula nana. Fine root production increased in fertilized plots during an unusually warm growing season, but remained unchanged in control
plots, consistent with observations that B. nana shows a positive response to climate warming. Calculations based on a few simple assumptions suggest changes in fine root
demography with long-term fertilization and species replacement could account for between 20 and 39% of the observed declines
in SOC stocks. 相似文献