117 research outputs found
Photosynthetic Response of Two Caragana Species to the Stimulated Climate Change in Mu Us Sand Land of Northwest China
Due to human activities, the concentration of carbon dioxide (CO2) in the Earth’s atmosphere is rising rapidly. The atmospheric CO2 concentration has increased to 360 μmol/mol from 280 μmol/mol at the end of the 19th century, and it will be doubled in the late 21st century (Alcamo 1996). Since CO2 is a key factor for plant growth and development, much more attention has been paid to the effect of an elevated atmospheric CO2 concentration on many ecosystem processes (Hungate et al. 1997; Idso et al. 1992; Oren et al. 2001; Sun et al. 2002).
Caragana davazamcii and Caragana korshinskii which belong to legumes family play an extremely important role in protection soil from the wind, water conservation and eco-environment protection in Mu Us sand land of Northwest China. There have been a lot of research done on ecophysiological characteristics of caragana species under natural conditions, but there has been little focused on the physiological changes that may occur under stimulated CO2 enrichment. This study compares the changes of photosynthetic characteristics of two caragana species to simultaneous CO2 enrichment and explores their adaptation mechanisms
Response of Dynamic Change of Vegetation Index to Precipitation Fluctuations in Hulunbeier Typical Steppe
In arid and semi-arid regions, precipitation is an important environmental limiting factor for ecosystems, where precipitation characteristic parameters at different time scales have great variability (Mohammad and Howard, 2006), and the small precipitation events (\u3c 5 mm) is the subject of precipitation events (Loik et al., 2004, Sala and Lauenroth, 1982). In this study, we used vegetation index extracted from TM or MODIS image to establish the regression models between vegetation index and precipitation, and then analyzed the response of typical steppe vegetation to precipitation fluctuations. Our result can supply reference for the productivity measurement model in typical steppe
Contributions of Different Regulatory Mechanisms to Osmotic Potential Changes in Three \u3cem\u3eCaragana\u3c/em\u3e Species on the Mongolian Plateau
The genus Caragana of legume family is endemic to the temperate grasslands of Eurasia (Cao et al., 1999). Caragana species are broadly distributed in the temperate Asia zone (E30°–140°, N28°–56°). Caragana microphylla, Caragana davazamcii, and Caragana korshinskii are typical representatives of the genus Caragana in central Asia. The three Caragana species exhibit a geographically substituted distribution from east (semi arid habitat) to west (arid habitat) on the Mongolian Plateau. Existing studies investigating the reasons for the interspecific geographical transition of the three Caragana species have primarily focused on RAPD analysis, photosynthetic capacity, and hydraulic architecture. In contrast, information on the adjustment mechanisms in Ψπ changes remains limited; particularly regarding the relative contributions of the main three regulatory mechanisms knows little
A Missense Mutation within the Helix Termination Motif of KRT25 Causes Autosomal Dominant Woolly Hair/Hypotrichosis
ClipCrop: Conditioned Cropping Driven by Vision-Language Model
Image cropping has progressed tremendously under the data-driven paradigm.
However, current approaches do not account for the intentions of the user,
which is an issue especially when the composition of the input image is
complex. Moreover, labeling of cropping data is costly and hence the amount of
data is limited, leading to poor generalization performance of current
algorithms in the wild. In this work, we take advantage of vision-language
models as a foundation for creating robust and user-intentional cropping
algorithms. By adapting a transformer decoder with a pre-trained CLIP-based
detection model, OWL-ViT, we develop a method to perform cropping with a text
or image query that reflects the user's intention as guidance. In addition, our
pipeline design allows the model to learn text-conditioned aesthetic cropping
with a small cropping dataset, while inheriting the open-vocabulary ability
acquired from millions of text-image pairs. We validate our model through
extensive experiments on existing datasets as well as a new cropping test set
we compiled that is characterized by content ambiguity
Scientific Opportunities with an X-ray Free-Electron Laser Oscillator
An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray
source that would produce fully coherent pulses with meV bandwidth and stable
intensity. The XFELO complements existing sources based on self-amplified
spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL)
that produce ultra-short pulses with broad-band chaotic spectra. This report is
based on discussions of scientific opportunities enabled by an XFELO during a
workshop held at SLAC on June 29 - July 1, 2016Comment: 21 pages, 12 figure
Forced Notch Signaling Inhibits Commissural Axon Outgrowth in the Developing Chick Central Nerve System
BACKGROUND: A collection of in vitro evidence has demonstrated that Notch signaling plays a key role in the growth of neurites in differentiated neurons. However, the effects of Notch signaling on axon outgrowth in an in vivo condition remain largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In this study, the neural tubes of HH10-11 chick embryos were in ovo electroporated with various Notch transgenes of activating or inhibiting Notch signaling, and then their effects on commissural axon outgrowth across the floor plate midline in the chick developing central nerve system were investigated. Our results showed that forced expression of Notch intracellular domain, constitutively active form of RBPJ, or full-length Hes1 in the rostral hindbrain, diencephalon and spinal cord at stage HH10-11 significantly inhibited commissural axon outgrowth. On the other hand, inhibition of Notch signaling by ectopically expressing a dominant-negative form of RBPJ promoted commissural axonal growth along the circumferential axis. Further results revealed that these Notch signaling-mediated axon outgrowth defects may be not due to the alteration of axon guidance since commissural axon marker TAG1 was present in the axons in floor plate midline, and also not result from the changes in cell fate determination of commissural neurons since the expression of postmitotic neuron marker Tuj1 and specific commissural markers TAG1 and Pax7 was unchanged. CONCLUSIONS/SIGNIFICANCE: We first used an in vivo system to provide evidence that forced Notch signaling negatively regulates commissural axon outgrowth
The potential impacts of climate change factors on freshwater eutrophication: Implications for research and countermeasures of water management in China
Water eutrophication has become one of the most serious aquatic environmental problems around the world. More and more research has indicated climate change as a major natural factor that will lead to the acceleration of eutrophication in rivers and lakes. However, understanding the mechanism of climate change's effect on water eutrophication is difficult due to the uncertainties caused by its complex, non-linear process. There is considerable uncertainty about the magnitude of future temperature changes, and how these will drive eutrophication in water bodies at regional scales under the effect of human activities. This review collects the existing international and domestic literature from the last 10 years, discussing the most sensitive factors of climate change (i.e., temperature, precipitation, wind, and solar radiation) and analyzing their interaction with water eutrophication. Case studies of serious eutrophication and algal bloom problems in China are discussed to further demonstrate the conclusion. Finally, adaptation countermeasures and related implications are proposed in order to foster the development of sustainability strategies for water management in China
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