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The sensitivity of soil organic carbon (SOC) decomposition in seasonally frozen soils, such as alpine ecosystems, to climate warming is a major uncertainty in global carbon cycling. Here we measure soil CO2 emission during four years (2018-2021) from the whole-soil warming experiment (4 °C for the top 1 m) in an alpine grassland ecosystem. We find that whole-soil warming stimulates total and SOC-derived CO2 efflux by 26% and 37%, respectively, but has a minor effect on root-derived CO2 efflux. Moreover, experimental warming only promotes total soil CO2 efflux by 7-8% on average in the meta-analysis across all grasslands or alpine grasslands globally (none of these experiments were whole-soil warming). We show that whole-soil warming has a much stronger effect on soil carbon emission in the alpine grassland ecosystem than what was reported in previous warming experiments, most of which only heat surface soils.

We conducted a systematic literature review examining the participant characteristics of studies of students with emotional disturbance (ED) with the purpose of better understanding potential similarities and differences between students with ED in research and the population of students with ED. Results indicate (a) participants with reported demographics were predominantly White or Black/African American and male; (b) participants in research samples were significantly different from the national population on gender, age, and race across study designs; (c) the research samples included significantly more White and Black/African American participants and fewer from other minority racial groups compared with the national population; (d) male participants were overrepresented and female underrepresented in studies generally, but the pattern was reversed in researcher-recruit samples; and (e) young children ages 3 to 5 years old were severely underrepresented in the research sample. We discuss the implications of this review and future directions for research.

ObjectiveThis study aimed to evaluate the capacity of domestic laboratories for the detection of Salmonella in milk powder.MethodsArtificially contaminated samples in this proficiency testing program were used. The samples were prepared by adding the bacterial enrichment solution to the matrix solution and then mixed， divided， and freeze-dried. The homogeneity and stability of the samples were tested. Three groups of proficiency testing samples were designed and two samples were randomly sent to each laboratory. The result was compared to the specified value to evaluate the performance of the laboratories that participated.ResultsA total of 337 laboratories in our country participated in the proficiency testing program， of which 323 were satisfactory， with the satisfaction rate at 95.8%； 14 laboratories had one or two unsatisfactory results. A total of 674 samples were sent to the laboratory， of which 658 had satisfactory results， with a satisfaction rate of 97.6%， 16 results were unsatisfactory accounting for 2.4%.ConclusionDifferent groups of samples were randomly numbered and randomly distributed， which played an essential role in preventing collusion. The samples prepared by the artificial pollution method fully considered the target bacteria， similar interference bacteria， and background bacteria， and were consistentwith the actual samples in terms of performance. The detection ability of Salmonella in the milk powder of national laboratories is generally satisfactory， and while a few laboratories need to be improved in terms of their detection capability.

ObjectiveThis study aimed to prepare proficiency testing samples that are closer to the actual samples and have good homogeneity and stability， and the ability of national laboratories to detect procymidone， carbofuran， and parathion in vegetables was analyzed through proficiency testing.MethodsThe proficiency testing samples were prepared by adding the target standard solution to the vegetable juice that was sold in the market， and the uniformity and stability were tested. The assigned value and standard deviation of proficiency testing were obtained by robust statistics， and the z value was applied to evaluate the results submitted by the participating laboratories.ResultsThe prepared samples were tested for homogeneity and stability， and met the proficiency testing requirements. The samples were applied to proficiency testing， and 94 laboratories participated nationwide， of which the laboratory satisfaction rate in the procymidone project was 84.5%； the laboratory satisfaction rate in the carbofuran project was 83.3%； the laboratory satisfaction rate in the parathion project was 89.6%.ConclusionThe sample prepared by the preparation method in this study has favorable homogeneity and stability and can meet the requirements of the sample for proficiency testing. The statistical results of proficiency testing showed that the detection ability of procymidone， carbofuran， and parathion in vegetables used in participating laboratories was generally favorable. Through this capability verification activity， we gained an understanding of the testing level of laboratories in this field and achieved the expected results.

The housekeeping genes atpD, gyrB, infB, fusA and glnS in Cronobacter sakazakii were selected as target sequences to construct plasmid standards for rapidly detecting C. sakazakii. The constructed recombinant plasmids was verified by colony polymerase chain reaction (PCR) and sequencing and was checked for stability after 15 passages. The atpD, gyrB, infB, fusA and glnS plasmid standards were qualitatively tested and evaluated in terms of limit of detection (LOD) and stability. Then, these plasmid standards were used to detect C. sakazakii in infant milk powder. The results of colony PCR and sequencing showed successful construction of the atpD, gyrB, infB, fusA and glnS plasmid standards. The PCR system was specific for the detection of the plasmid standards. The detection limits of atpD, gyrB, infB, fusA and glnS were 1.14 × 106, 1.07 × 107, 1.09 × 107, 1.73 × 105 and 7.54 × 105 copies/μL, respectively. The lyophilized plasmids could be stored stably at −20, 4 and 25 ℃ for 90 days. The plasmid standards were used to detect 23 samples of infant milk powder, and one of them was detected positive for gyrB. However, C. sakazakii was undetectable by the traditional national standard method (GB 4789.40-2016). Compared with the traditional method, the application of the plasmid standards greatly improved the detection efficiency of samples.