Spiral ganglion (SG) neurons of the cochlea convey all auditory inputs to the brain, yet the cellular and molecular complexity necessary to decode the various acoustic features in the SG has remained ...unresolved. Using single-cell RNA sequencing, we identify four types of SG neurons, including three novel subclasses of type I neurons and the type II neurons, and provide a comprehensive genetic framework that define their potential synaptic communication patterns. The connectivity patterns of the three subclasses of type I neurons with inner hair cells and their electrophysiological profiles suggest that they represent the intensity-coding properties of auditory afferents. Moreover, neuron type specification is already established at birth, indicating a neuronal diversification process independent of neuronal activity. Thus, this work provides a transcriptional catalog of neuron types in the cochlea, which serves as a valuable resource for dissecting cell-type-specific functions of dedicated afferents in auditory perception and in hearing disorders.
•The marine sources largely contribute to precipitation amount and the lower isotopic values in the MLYRB.•The regional effect of precipitation amount and cloud cover on precipitation isotopes is ...more remarkable than local effect.•The mean subcloud evaporation fraction is greater during the rainy season compared with that during the dry season.•Strong convection in the upstream moisture transport region is the key control on precipitation isotopes in the MLYRB.
Paleoclimatic records in the East Asian monsoon region (EAM) depend on precipitation isotopes as proxies for past hydroclimatic variability. However, the potential mechanisms controlling precipitation isotopic variability in this region remain poorly understood. This study collected daily precipitation isotopes in the middle-lower reaches of the Yangtze River Basin from 2017 to 2020 to explore how convective behaviors and moisture sources determining the variability of precipitation stable isotopes. Daily precipitation δ18O presented a weak inverse relationship with local precipitation amount and air temperature. Results of correlation analysis showed that the maximum correlation zones of precipitation δ18O between different cloud levels and outgoing long wave radiation were identified in the upstream regions such as the Indian Peninsula, BoB, and Indo-China Peninsula during the rainy season. Back-trajectory analysis showed that substantial water vapor from maritine sources in the Indian Ocean and the Bay of Bengal (BoB) largely contributed to the lower δ18O values during the rainy season (−7.5 ‰) because of intense rainout processes in the upstream sourced regions, demonstrated by significant regional correlation between precipitation δ18O and regional precipitation amount. The regional correlations were stronger in the upstream regions than the local influences, indicating that precipitation isotopes in this region are more influenced by regional convective processes in the upstream region during the rainy season. Using the modified Stewart model, the mean subcloud evaporation fraction estimated was greater in rainy season (24.1 % vs 36.1 % for HK and HZ, respectively) than that in dry season (15.1 % vs 19.9 % for HK and HZ, respectively). These findings highlight the importance of upstream processes in controlling precipitation isotopes in the EAM region and provide reliable evidence on the interpretation of monsoonal climate variability.
Proprioceptive neurons (PNs) are essential for the proper execution of all our movements by providing muscle sensory feedback to the central motor network. Here, using deep single cell RNAseq of ...adult PNs coupled with virus and genetic tracings, we molecularly identify three main types of PNs (Ia, Ib and II) and find that they segregate into eight distinct subgroups. Our data unveil a highly sophisticated organization of PNs into discrete sensory input channels with distinct spatial distribution, innervation patterns and molecular profiles. Altogether, these features contribute to finely regulate proprioception during complex motor behavior. Moreover, while Ib- and II-PN subtypes are specified around birth, Ia-PN subtypes diversify later in life along with increased motor activity. We also show Ia-PNs plasticity following exercise training, suggesting Ia-PNs are important players in adaptive proprioceptive function in adult mice.
Anchovy (Engraulis japonicus) is a small, low-value, marine fish and is mainly targeted for nonfood uses. In this study, the enzymatic preparation and properties of iron-chelating peptides from ...anchovy muscle protein were evaluated. The results showed that the trypsin hydrolysate possessed the greatest iron-chelating activity, and the iron-chelating activity was governed by the degree of hydrolysis (DH) and the iron-chelating conditions (temperature and pH). Among the gel-filtration fractions, Fraction 1 and Fraction 3 exhibited higher iron-chelating activities, and the IC50 values were 0.048 and 0.086mg/ml, respectively. A novo trypsin-resistant, large-molecular-weight, iron-chelating fraction was purified from Fraction 1, and was identified to be homologous with the conserved domain of the coiled-coil myosin heavy-chain tail region. Fraction 3 yielded two oligopeptides, Ser-(Gly)7-Leu-Gly-Ser-(Gly)2-Ser-Ile-Arg and Ile-(Glu)2-Leu-(Glu)3-Ile-Glu-Ala-Glu-Arg. We thus conclude that anchovy might be beneficial as a bioresource to produce anti-anemia compounds which can be used in functional foods.
► Anchovy is a promising resource for enzymatic production of iron-chelating peptides. ► The iron-chelating ability of peptides is dependent on pH and temperature. ► Two oligopeptides R.SGGGGGGGLGSGGSIR.S and R.IEELEEEIEAER.A were identified.
Quorum-sensing signals in refrigerated shrimp (Litopenaeus vannamei) undergoing spoilage were examined using bioreporter assays, thin-layer chromatography and gas chromatography–mass spectrometry, ...and the results revealed the presence of three types of autoinducers including acetylated homoserine lactones (AHLs) (i.e., N-hexanoyl-homoserine lactone, N-oxohexanoyl-homoserine lactone and N-octanoyl-homoserine lactone), autoinducer-2, and cyclic dipeptides (i.e., cyclo-(l-Pro-l-Leu), cyclo-(l-Leu-l-Leu) and cyclo-(l-Pro-l-Phe)). Autoinducer-2, rather than any AHL, was detected in extracts from pure cultures of the specific spoilage organisms (SSO), i.e., Shewanella putrefaciens (SS01) and Shewanella baltica (SA02). As for the cyclic peptides, only SA02 was determined to produce cyclo-(l-Pro-l-Leu). According to the transcription levels of LuxR (the master quorum-sensing regulator) in the SSO in response to exogenous autoinducers, the SSO could sense AHLs and cyclo-(l-Leu-l-Leu), rather than autoinducer-2, cyclo-(l-Leu-l-Leu) and cyclo-(l-Pro-l-Phe). In accordance with the results of LuxR expression, the production of biofilm matrixes and extracellular proteases in the SSO was regulated by exogenous AHLs and cyclo-(l-Pro-l-Leu), rather than 4,5-dihydroxy-2,3-pentanedione (the autoinducer-2 precursor), cyclo-(l-Leu-l-Leu) and cyclo-(l-Pro-l-Phe). Exogenous N-hexanoyl-homoserine lactone and cyclo-(l-Pro-l-Leu) increased the growth rates and population percentages of the SSO in shrimp samples under refrigerated storage, and interestingly, exogenous 4,5-dihydroxy-2,3-pentanedione also increased the population percentages of the SSO in vivo by inhibiting the growth of the competing bacteria. However, according to the levels of TVB-N and the volatile organic components in the shrimp samples, exogenous 4,5-dihydroxy-2,3-pentanedione did not accelerate the shrimp spoilage process as N-hexanoyl-homoserine lactone and cyclo-(l-Pro-l-Leu) did. In summary, our results suggest that quorum sensing involves the spoilage of refrigerated Litopenaeus vannamei.
•Two Shewanella spp. were the specific spoilage organisms of refrigerated shrimp.•Three types of autoinducers were present in refrigerated shrimp.•The specific spoilage organisms involve three types of quorum sensing systems.•Quorum sensing regulates public good production in the specific spoilage organisms.•Quorum sensing promotes the competitiveness of the specific spoilage organisms.
•Stability, component and source of soil WEOM were studied during 360-day incubation.•Humic(fulvic)-like and protein-like components dominated soil WEOM.•Freeze-thaw retarded humic- and fulvic-like ...WEOM components release from litter.•Dynamics of WEOM quantity and quality are related to altered microbial properties.
Future climatic change is likely to increase the occurrence of soil freeze–thaw (FT) events in high latitude and/or high altitude zones, which can substantially influence the dynamics of dissolved organic matter (DOM) released into the soils. However, it is not clear how the quantity and quality of soil DOM respond to changing FT patterns under different soil moisture and litter manipulation conditions in northern temperate forest stands. In this study, litter-amended and non-amended forest soils were incubated for 360 days at three soil moisture levels (30%, 60%, and 90% water-filled pore space) and three intensities of FT disturbance (low, high, and none). We quantified heterotrophic respiration, enzyme activity, microbial biomass, and water-extractable organic matter (WEOM) as a proxy for DOM in soils during the incubation experiment. The quality of WEOM was characterized by biodegradability, UV absorbance and parallel factor analysis modelling of fluorescence excitation emission matrices. Concentrations of water-extractable organic carbon (WEOC) and biodegradable WEOC declined continuously in all treatments over the 360-day incubation period. The dominant component of fluorescent WEOM shifted from humic- and fulvic- like components during the first 108 days of incubation, to protein-like components of microbial origin, characterized by high aromaticity, at the end of the incubation period. Litter amendment, FT disturbance, and their interaction increased WEOC concentrations in soils during the early 108-day incubation period, particularly in soils with low moisture and high FT intensity, but these increases disappeared after 252 days incubation at 15 °C. Litter-derived fluorescent WEOM in soils without FT disturbance was dominated by protein-like components after 14 days of incubation, but these were replaced by humic- and fulvic-like components after 108 days. This replacement effect was weaker in soils with FT disturbance, which we attribute to changes in microbial properties, including enzyme activity, microbial biomass and activity.
Climate change scenarios predict a change in the rainfall regimes for this current century, which has different impacts on soil greenhouse gas (GHG) fluxes. However, how changes in annual rainfall ...affect annual GHG fluxes of forest soils remain unknown. A six-year field experiment with −25% and −50% throughfall (TF) and +25% TF manipulation was performed to explore the mechanisms involving GHG fluxes under a mature temperate forest, northeastern China and to work out whether the TF effect sizes on annual soil GHG fluxes vary with dry and wet years. The results showed that both −25% TF and −50% TF treatments depressed annual soil nitrous oxide (N2O) and carbon dioxide (CO2) emissions but increased annual soil methane (CH4) uptake. A contrary pattern of annual soil GHG fluxes was observed in the +25% TF treatment. When annual TF input was decreased by 100 mm, annual soil N2O and CO2 emissions were decreased by 18.1 ± 3.1 mg N m−2 and by 39.4 ± 6.1 g C m−2 during the growing season, respectively, and annual soil CH4 uptake was increased by 11.5 ± 3.4 mg C m−2. Both −25% TF and −50% TF treatments reduced annual soil dissolved organic C (DOC) leaching by 29.3% and 45.6% and dissolved total N (DN) leaching by 30.8% and 39.6%, respectively. Contrary to annual soil N2O and CO2 emissions, annual soil CH4 uptake during the growing season significantly decreased with an increase in the annual leaching fluxes of soil DOC, inorganic N, and DN. Besides soil moisture and temperature and pH, soil GHG fluxes under manipulating TF condition were regulated by soil labile C and N status. Our findings indicated that the TF effect sizes on both annual GHG fluxes and net annual GHG balance (GWP) of forest soils varied with dry and wet years in northeastern China. The results highlight the importance of altered annual rainfall in regulating annual soil GHG fluxes and the GWP in temperate forests under global climate change.
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•Effects of throughfall on soil GHG fluxes in forest ecosystems were studied.•Throughfall reduction reduced soil N2O and CO2 fluxes but increased CH4 uptake.•Soil moisture and temperature jointly affected N2O and CO2 fluxes and CH4 uptake.•Soil GHG fluxes upon altered throughfall were related to soil DOC and DN leaching.•Throughfall effect sizes on soil GHG fluxes and GWP varied with dry and wet years.
It is necessary to develop polymer materials with excellent mechanical properties and can be quickly repaired under reasonable conditions. However, it is difficult to simultaneously optimize the ...mechanical properties and repair conditions as they have conflicting realization requirements. In this study, we prepare a thermoplastic polyurethane (I-4-P-HM) containing two kinds of alicyclic isocyanate with a tensile strength and toughness of 11.35 MPa and 64.1 MJ m−3, respectively. The mechanical properties of the cut and spliced I-4-P-HM films can be completely restored to their original values at near body temperature (40 °C) in only 2 h. In I-4-P-HM, isophorone diisocyanate (IPDI) directly connect to aromatic disulfide that enables a more efficient exchange of the aromatic disulfides, while dicyclohexylmethane 4,4′-diisocyanate (HMDI) with a symmetrical alicyclic structure endows the TPU with better mechanical properties. The two work together to make polyurethane have good mechanical properties and can be repaired quickly under mild condition. Furthermore, we carried out the scratch recovery experiments on I-4-P-HM covered with a layer of conductive silver paste, and the results indicate that this TPU has the potential to be applied in the flexible electronics industry.
I-4-P-HM prepared by two different kinds alicyclic isocyanates not only have excellent mechanical properties, but also can be quickly repaired at near body temperature (40 °C). Display omitted
•Polyurethanes are prepared from mixed isocyanates.•The mechanical strength and toughness of I-4-P-HM can be achieved 11.35 MPa and 64.1 MJ m3, respectively.•I-4-P-HM can be completely repaired in 2 h at 40 °C.•The polyurethanes obtained in this paper have certain repairing ability at near body temperature.
Somatic sensation is defined by the existence of a diversity of primary sensory neurons with unique biological features and response profiles to external and internal stimuli. However, there is no ...coherent picture about how this diversity of cell states is transcriptionally generated. Here, we use deep single cell analysis to resolve fate splits and molecular biasing processes during sensory neurogenesis in mice. Our results identify a complex series of successive and specific transcriptional changes in post-mitotic neurons that delineate hierarchical regulatory states leading to the generation of the main sensory neuron classes. In addition, our analysis identifies previously undetected early gene modules expressed long before fate determination although being clearly associated with defined sensory subtypes. Overall, the early diversity of sensory neurons is generated through successive bi-potential intermediates in which synchronization of relevant gene modules and concurrent repression of competing fate programs precede cell fate stabilization and final commitment.
Non-point source pollution is a serious environmental issue and has attracted a lot of scientific attention. Currently, the influences of grazing on the water and nutrient cycles in alpine meadows, ...as well as corresponding underlying mechanisms, still remain unclear. The quantitative contributions of influence variables to the nutrient loading variations in rivers and streams in alpine-meadow watersheds need to be elucidated. In the study, the Soil and Water Assessment Tool (SWAT) was applied to a typical alpine-meadow watershed (the Buha River Basin, BRB) on the Tibetan Plateau, where non-intensive grazing and farming were developed, to reproduce the water and nutrient cycles. Results showed that SWAT model performed well in simulating monthly streamflow, TN, and TP fluxes from 2016 to 2022 (NSE > 0.6). Grazing slightly increased the streamflow by 4.27% because it reduced aboveground biomass and leaf area index of vegetation, which subsequently reduced the ET of grasslands. Grazing increased the annual NH4-N fluxes by 0.50% due to livestock manure inputs to the basin; in contrast, grazing reduced the annual fluxes of TN and TP of Buha River by 3.36% and 0.48%, respectively, during 2016 – 2022, which were driven by the increased plant uptake of NO3-N/soluble P from soil layer due to grazing. As a result, non-intensive grazing was beneficial for the water management and nutrient control in the studied alpine-meadow watershed. The hydrological, water-quality, and meteorological variables accounted for 30.78%, 28.27%, and 21.23% of the variations in N fluxes in Buha River, respectively. The dissolved oxygen (10.68%), soluble phosphorus (10.51%), precipitation (6.27%), overland flow (5.60%), and water temperature (5.53%) each explained more than 5% of the N flux variations. The present study quantified the effects of grazing and farming on stream nutrient fluxes based on mathematical modeling and statistical methods, and the findings could provide scientific supports for the managements of alpine-meadow watersheds.
•SWAT could be used to simulate the nutrient cycle of pastures on Tibetan Plateau.•Grazing increased streamflow by reducing ET of grasslands in the study basin.•Grazing reduced fluxes of TN and TP by 3.36% and 0.48%, respectively, in Buha River.•Hydrological and water-quality variables explained 60% of river N-flux variations.•Moderate grazing might be beneficial for the nutrient control in alpine meadows.
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