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31.
32.
Kristine Y. Crous Audrey G. Quentin Yan‐Shih Lin Belinda E. Medlyn David G. Williams Craig V. M. Barton David S. Ellsworth 《Global Change Biology》2013,19(12):3790-3807
Eucalyptus species are grown widely outside of their native ranges in plantations on all vegetated continents of the world. We predicted that such a plantation species would show high potential for acclimation of photosynthetic traits across a wide range of growth conditions, including elevated [CO2] and climate warming. To test this prediction, we planted temperate Eucalyptus globulus Labill. seedlings in climate‐controlled chambers in the field located >700 km closer to the equator than the nearest natural occurrence of this species. Trees were grown in a complete factorial combination of elevated CO2 concentration (eC; ambient [CO2] +240 ppm) and air warming treatments (eT; ambient +3 °C) for 15 months until they reached ca. 10 m height. There was little acclimation of photosynthetic capacity to eC and hence the CO2‐induced photosynthetic enhancement was large (ca. 50%) in this treatment during summer. The warming treatment significantly increased rates of both carboxylation capacity (Vcmax) and electron transport (Jmax) (measured at a common temperature of 25 °C) during winter, but decreased them significantly by 20–30% in summer. The photosynthetic CO2 compensation point in the absence of dark respiration (Γ*) was relatively less sensitive to temperature in this temperate eucalypt species than for warm‐season tobacco. The temperature optima for photosynthesis and Jmax significantly changed by about 6 °C between winter and summer, but without further adjustment from early to late summer. These results suggest that there is an upper limit for the photosynthetic capacity of E. globulus ssp. globulus outside its native range to acclimate to growth temperatures above 25 °C. Limitations to temperature acclimation of photosynthesis in summer may be one factor that defines climate zones where E. globulus plantation productivity can be sustained under anticipated global environmental change. 相似文献
33.
Rene M van der Sluis Lamin B Cham Albert GrisOliver Kristine R Gammelgaard Jesper G Pedersen Manja Idorn Ulvi Ahmadov Sabina Sanches Hernandez Ena Cmalovic Stine H Godsk Jacob Thyrsted Jesper D Gunst Silke D Nielsen Janni J Jrgensen Tobias Wang Bjerg Anders Laustsen Line S Reinert David Olagnier Rasmus O Bak Mads Kjolby Christian K Holm Martin Tolstrup Sren R Paludan Lasse S Kristensen Ole S Sgaard Martin R Jakobsen 《The EMBO journal》2022,41(10)
Understanding the molecular pathways driving the acute antiviral and inflammatory response to SARS‐CoV‐2 infection is critical for developing treatments for severe COVID‐19. Here, we find decreasing number of circulating plasmacytoid dendritic cells (pDCs) in COVID‐19 patients early after symptom onset, correlating with disease severity. pDC depletion is transient and coincides with decreased expression of antiviral type I IFNα and of systemic inflammatory cytokines CXCL10 and IL‐6. Using an in vitro stem cell‐based human pDC model, we further demonstrate that pDCs, while not supporting SARS‐CoV‐2 replication, directly sense the virus and in response produce multiple antiviral (interferons: IFNα and IFNλ1) and inflammatory (IL‐6, IL‐8, CXCL10) cytokines that protect epithelial cells from de novo SARS‐CoV‐2 infection. Via targeted deletion of virus‐recognition innate immune pathways, we identify TLR7‐MyD88 signaling as crucial for production of antiviral interferons (IFNs), whereas Toll‐like receptor (TLR)2 is responsible for the inflammatory IL‐6 response. We further show that SARS‐CoV‐2 engages the receptor neuropilin‐1 on pDCs to selectively mitigate the antiviral interferon response, but not the IL‐6 response, suggesting neuropilin‐1 as potential therapeutic target for stimulation of TLR7‐mediated antiviral protection. 相似文献
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35.
Pei Dong Jessica Flores Kristine Pelton Keith R. Solomon 《Journal of cellular biochemistry》2010,111(5):1367-1374
Cholesterol is essential in establishing most functional animal cell membranes; cells cannot grow or proliferate in the absence of sufficient cholesterol. Consequently, almost every cell, tissue, and animal tightly regulates cholesterol homeostasis, including complex mechanisms of synthesis, transport, uptake, and disposition of cholesterol molecules. We hypothesize that cellular recognition of cholesterol insufficiency causes cell cycle arrest in order to avoid a catastrophic failure in membrane synthesis. Here, we demonstrate using unbiased proteomics and standard biochemistry that cholesterol insufficiency causes upregulation of prohibitin, an inhibitor of cell cycle progression, through activation of a cholesterol‐responsive promoter element. We also demonstrate that prohibitin protects cells from apoptosis caused by cholesterol insufficiency. This is the first study tying cholesterol homeostasis to a specific cell cycle regulator that inhibits apoptosis. J. Cell. Biochem. 111: 1367–1374, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
36.
Edward B. Blanchard Maria L. Peters Christiane Hermann Shannon M. Turner Todd C. Buckley Kristine Barton Mark P. Dentinger 《Applied psychophysiology and biofeedback》1997,22(4):227-245
In order to test for the specific therapeutic effects of thermal biofeedback (TBF) for hand warming on vascular headache (HA),
70 patients with chronic vascular HA were randomly assigned to TBF for hand warming, TBF for hand cooling, TBF for stabilization
of hand temperature, or biofeedback to suppress alpha in the EEG. Patients in each condition initially had high levels of
expectation of therapeutic benefit and found the treatment rationales highly credible. Participants in each condition received
12 treatment sessions on a twice-per-week basis. Based on daily HA diary data gathered for 4 weeks prior to treatment and
4 weeks after treatment, HA Index was significantly (p=.003) reduced as was HA medication consumption. There were no differential
reducations in HA Index or Medication Index among the four conditions. Global self-reports of improvement gathered at the
end of the post-treatment monitoring period also did not differ among the four conditions. We were unable to demonstrate a
specific effect of TBF for hand warming on vascular HA activity. 相似文献
37.
V. Bala Chaudhary Kristine Akland Nancy C. Johnson Matthew A. Bowker 《Restoration Ecology》2020,28(Z2):S115-S126
Biological soil crusts (biocrusts) and arbuscular mycorrhizal (AM) fungi are communities of soil organisms often targeted to assist in the achievement of multiple ecological restoration goals. In drylands, benefits conferred from biocrust and AM fungal inoculation, such as improved native plant establishment and soil stabilization, have primarily been studied separately. However, comparisons between these two types of soil inoculants and investigations into potential synergies between them, particularly at the plant community scale, are needed to inform on‐the‐ground management practices in drylands. We conducted two full‐factorial experiments—one in greenhouse mesocosms and one in field plots—to test the effects of AM fungal inoculation, biocrust inoculation, and their interaction on multiple measures of dryland restoration success. Biocrust inoculation promoted soil stabilization and plant drought tolerance, but had mixed effects on native plant diversity (positive in greenhouse, neutral in field) and productivity (negative in greenhouse, neutral in field). In greenhouse mesocosms, biocrust inoculation reduced plant biomass, which was antagonistic to % root length colonized by AM fungi. Inoculation with native or commercial AM fungi did not influence plant establishment, drought tolerance, or soil stabilization in either study, and few synergistic effects of simultaneous inoculation of AM fungi and biocrusts were observed. These results suggest that, depending on the condition of existing soil communities, inoculation with AM fungi may not be necessary to promote dryland restoration goals, while inoculation with salvaged biocrust inoculation may be beneficial in some contexts. 相似文献
38.
L. Geris H. Van Oosterwyck J. Vander Sloten J. Duyck I. Naert 《Computer methods in biomechanics and biomedical engineering》2013,16(5-6):277-288
Nowadays, there is a growing consensus on the impact of mechanical loading on bone biology. A bone chamber provides a mechanically isolated in vivo environment in which the influence of different parameters on the tissue response around loaded implants can be investigated. This also provides data to assess the feasibility of different mechanobiological models that mathematically describe the mechanoregulation of tissue differentiation. Before comparing numerical results to animal experimental results, it is necessary to investigate the influence of the different model parameters on the outcome of the simulations. A 2D finite element model of the tissue inside the bone chamber was created. The differentiation models developed by Prendergast, et al. [“Biophysical stimuli on cells during tissue differentiation at implant interfaces”, Journal of Biomechanics, 30(6), (1997), 539–548], Huiskes et al. [“A biomechanical regulatory model for periprosthetic fibrous-tissue differentiation”, Journal of Material Science: Materials in Medicine, 8 (1997) 785–788] and by Claes and Heigele [“Magnitudes of local stress and strain along bony surfaces predict the course and type of fracture healing”, Journal of Biomechanics, 32(3), (1999) 255–266] were implemented and integrated in the finite element code. The fluid component in the first model has an important effect on the predicted differentiation patterns. It has a direct effect on the predicted degree of maturation of bone and a substantial indirect effect on the simulated deformations and hence the predicted phenotypes of the tissue in the chamber. Finally, the presence of fluid also causes time-dependent behavior. Both models lead to qualitative and quantitative differences in predicted differentiation patterns. Because of the different nature of the tissue phenotypes used to describe the differentiation processes, it is however hard to compare both models in terms of their validity. 相似文献
39.
N. Amor L. Geris J. Vander Sloten 《Computer methods in biomechanics and biomedical engineering》2013,16(4):459-468
The objective of this study was to see whether a mathematical model of fracture healing was able to mimic bone formation around an unloaded screw-shaped titanium implant as it is well-believed that both processes exhibit many biological similarities. This model describes the spatio-temporal evolution of cellular activities, ranging from mesenchymal stem cell migration, proliferation, differentiation to bone formation, which are initiated and regulated by the growth factors present at the peri-implant site. For the simulations, a finite volume code was used and adequate initial and boundary conditions were applied. Two sets of analyses have been performed, in which either initial and boundary condition or model parameter values were changed with respect to the fracture healing model parameter values. For a number of combinations, the spatio-temporal evolution of bone density was well-predicted. However reducing cell proliferation rate and increasing osteoblast differentiation and osteogenic growth factor synthesis rates, the simulation results were in agreement with the experimental data. 相似文献
40.