Response patterns of simulated corn yield and soil nitrous oxide emission to precipitation change

Background Precipitation plays an important role in crop production and soil greenhouse gas emissions.However,how crop yield and soil nitrous oxide(N_(2)O)emission respond to precipitation change,particularly with different background precipitations(dry,normal,and wet years),has not been well investigated.In this study,we examined the impacts of precipitation changes on corn yield and soil N_(2)O emission using a long-term(1981-2020,40 years)climate dataset as well as seven manipulated precipitation treatments with different background precipitations using the DeNitrification-DeComposition(DNDC)model.Results Results showed large variations of corn yield and precipitation but small variation of soil N_(2)O emission among 40 years.Both corn yield and soil N_(2)O emission showed near linear relationships with precipitation based on the long-term precipitation data,but with different response patters of corn yield and soil N_(2)O emission to precipitation manipulations.Corn yield showed a positive linear response to precipitation manipulations in the dry year,but no response to increases in precipitation in the normal year,and a trend of decrease in the wet year.The extreme drought treatments reduced corn yield sharply in both normal and wet years.In contrast,soil N_(2)O emission mostly responded linearly to precipitation manipulations.Decreases in precipitation in the dry year reduced more soil N_(2)O emission than those in the normal and wet years,while increases in precipitation increased more soil N_(2)O emission in the normal and wet years than in the dry year.Conclusions This study revealed different response patterns of corn yield and soil N_(2)O emission to precipitation and highlights that mitigation strategy for soil N_(2)O emission reduction should consider different background climate conditions.

Determinants of Response Pattern of Cochlear Nucleus Neuron:a Study Based on the Model

Objective: Neurons in the cochlear nucleus show different response patterns to the short tone bursts. Because of the limitations of animal experiments, it is hard to explore the principle. Therefore, using a model to simulate CN neurons will be a feasible way. Methods: Based on the initial model mentioned in the previous study, we proposed an improved CN model in MATLAB R2012b. Results: By modifying the parameters of the model we found the interchanges among "primary-like", "chopper",and "onset" response patterns. Furthermore, we simulated the "pauser" response pattern by adding an extra input in our model. Conclusion: The results indicate that the synaptic integrations and the input modes can give rise to different characteristics of CN neurons, which eventually determine the response patterns of CN neurons.

Molecular characterization and developmental expression patterns of thyroid hormone receptors(TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.

Exposure to heat-inactivated Trichophyton rubrum resulting in a limited immune response of human keratinocytes

Background Trichophyton rubrum （T. rubrum） represents the most important agent of dermatophytosis in humans. T. rubrum infection causes slight inflammation, and tends to be chronic and recurrent. It is suggested that it may result from the failure of epithelial cells to recognize T. rubrum effectively and initiate effective immune responses. The C-type lectin receptors （CLR） and toll-like receptors （TLR） are the two major pattern recognition receptors （PRRs） that recognize fungal components. Therefore, the purpose of the study was to analyze the expression of those PRRs and the cytokines in HaCaT cells stimulated with heat-inactivated T. rubrum conidia and hyphae, respectively. Methods HaCaT cells were unstimulated or stimulated with heat-inactivated T. rubrum conidia and hyphae （l×106 and 1.5×105 colony-forming unit （CFU） in 2 ml medium, respectively） for 6, 12 and 24 hours. The mRNA expression of PRRs involved in recognizing fungal pathogen-associated molecular patterns （PAMPs） and signaling molecules were measured by quantitative reverse transcription polymerase chain reaction （RT-PCR）. Meanwhile, surface toll-like receptor （TLR） 2, TLR4 and Dectin-1 were analyzed by fluorescence-activated cell sorter （FACS） 24 hours after treatment. The cytokines were detected in cell culture supernatants of HaCaT cells in 12 and 24 hours after treatment. Results HaCaT cells constitutively expressed mRNA of membrane-bound TLR1,2, 4 and 6, Dectinl and DC-SIGN, but not Dectin-2 or Mincle. Heat-killed T. rubrum did not significantly upregulate gene transcriptions of the PRRs of HaCaT cells. Heat-inactivated T. rubrum conidia significantly reduced the surface expression of TLR2 and Dectin-1, and suppressed the secretions of interferon-inducible protein-10 （IP-10） and monocyte chemotactic protein-1 （MCP-1） of HaCaT cells, while heat-killed T. rubrum hyphae significantly induced the secretions of IP-10 and MCP-I. Conclusion The cell-wall antigens of T. rubrum fail to activate transcriptional expression of PRRs and induce a lower immune response of HaCaT cells by limited cytokines secretion.

Prediction of H7N9 epidemic in China

Background In March 2013,human cases of infection with a novel A （H7N9） influenza virus emerged in China.The epidemic spread quickly and as of 6 May 2013,there were 129 confirmed cases.The purpose of this study was to analyze the epidemiology of the confirmed cases,determine the impacts of bird migration and temperature changes on the H7N9 epidemic,predict the future trends of the epidemic,explore the response patterns of the government and propose preventive suggestions.Methods The geographic,temporal and population distribution of all cases reported up to 6 May 2013 were described from available records.Risk assessment standard was established by analysing the temperature and relative humidity records during the period of extensive outbreak in three epidemic regions in eastern China,including Shanghai,Zhejiang and Jiangsu provinces.Risk assessment maps were created by combining the bird migration routes in eastern China with the monthly average temperatures from May 1993 to December 2012 nationwide.Results Among the confirmed cases,there were more men than women,and 50.4％ were elderly adults （age ＞61 years）.The major demographic groups were retirees and farmers.The temperature on the days of disease onset was concentrated in the range of 9℃-19℃; we defined 9℃-19℃ as the high-risk temperature range,0℃-9℃ or 19℃-25℃ as medium risk and ＜0℃ or ＞25℃ as low risk.The relative humidity on the days of disease onset ranged widely from 25％ to 99％,but did not correlate with the incidence of infection.Based on the temperature analysis and the eastern bird migration routes,we predicted that after May,the high-risk region would move to the northeast and inland,while after September,it would move back to north China.Conclusions Temperature and bird migration strongly influence the spread of the H7N9 virus.In order to control the H7N9 epidemic effectively,Chinese authorities should strengthen the surveillance of migrating birds,increase poultry and environmental sampling,improve live poultry selling and husbandry patterns and move from a ＂passive response pattern＂to an ＂active response pattern＂ in focused preventive measures.

Species-or genus-dependent immunostimulatory effects of gut-derived potential probiotics

The immune regulatory effects of probiotics have been widely recognized to be strain-specific.However,it is unknown if there is a species-or genus-dependent manner.In this study,we use an in vitro mesenteric lymph node(MLN)model to systematically evaluate the immunostimulatory effects of gut-derived potential probiotics.The results exhibit an obvious species or genus consensus immune response pattern.RNA-seq shows that T cell-dependent B cell activation and antibody responses may be inherent to this model.Of the five tested genera,Akkermansia spp.and Clostridium butyrium directly activate the immune response in vitro,as indicated by the secretion of interleukin-10.Bifidobacterium spp.and Bacteroides spp.activate immune response with the help of stimuli(anti-CD3 and anti-CD28 antibodies).Lactobacillus spp.blunt the immune response with or without stimuli.Further investigations show that the cell surface protein of A.muciniphila AH39,which may serve as a T cell receptor cognate antigen,might evoke an in vitro immune activation.In vivo,oral administration of A.muciniphila AH39 influences the proportion of T regulatory cells(Tregs)in MLNs and the spleen under homeostasis in both specific pathogen-free and germ-free mice.All these findings indicate the distinct effects of different genera or species of potential gut-derived probiotics on intestinal and systemic immunity.

From SARS to COVID-19:Is interdisciplinary research progressed in responding to another global pandemic?

Interdisciplinary research(IDR)plays a vital role in tackling grand and complex challenges such as COVID-19,which has severe consequences for public health,economy,politics,and society.This study compares several facets of interdisciplinarity that occurred in the research relating to two serious global pandemics in this century,namely SARS and COVID-19,and provides a comprehensive summary of the performance and growth of pandemic-related interdisciplinary research.Generally,the scientific community gathers more multidisciplinary efforts to tackle COVID-19 in comparison to SARS.Firstly,COVID-19 related research from each major field has greater connections with their established expertise and research threads such that they are studying the impact of COVID-19 on their own existing research subjects,while the studies of SARS by different disciplines exhibit less discernable disciplinary characteristics.Secondly,as for the interdisciplinarity observed in the knowledge base of pandemic-related publications,we observe a greater presence of social science knowledge and a more dispersed distribution of knowledge from various disciplines comparing publications on COVID-19 with SARS.Thirdly,regarding interdisciplinarity in research collaboration,COVID-19 publications are on average produced by more interdisciplinary teams than SARS,as measured by the number and diversity of affiliated disciplines of authors.Our discovery on the growth of multidisciplinarity and interdisciplinarity in pandemic-related research signals positive achievement that the scientific community is responding to such a global challenge as a whole and is willing to break down existing disciplinary silos to facilitate the flow of knowledge and breed novelty.