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

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

The effects of litter input and increased precipitation on soil microbial communities in a temperate grassland

Global warming has contributed to shifts in precipitation patterns and increased plant productivity, resulting in a significant increase in litter input into the soils. The enhanced litter input, combined with higher levels of precipitation, may potentially affect soil microbial communities. This study aims to investigate the effects of litter input and increased precipitation on soil microbial biomass, community structure, and diversity in a temperate meadow steppe in northeastern China. Different levels of litter input (0%, +30%, +60%) and increased precipitation (0%, +15%, +30%) were applied over a three-year period (2015–2017). The results showed that litter input significantly increased the biomass of bacteria and fungi without altering their diversity, as well as the ratio of bacterial to fungal biomass. Increased precipitation did not have a notable effect on the biomass and diversity of bacteria and fungi, but it did increase the fungal-to-bacterial biomass ratio. However, when litter input and increased precipitation interacted, bacterial diversity significantly increased while the fungal-to-bacterial biomass ratio remained unchanged. These findings indicate that the projected increases in litter and precipitation would have a substantial impact on soil microbial communities. In energy-and water-limited temperate grasslands, the additional litter inputs and increased precipitation contribute to enhanced nutrient and water availability, which in turn promotes microbial growth and leads to shifts in community structure and diversity

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