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The extreme climate events such as El Nino seriously threaten crop production and agro-ecological sustainability because of the aggravated environmental stresses worldwide, particularly in sub-Saharan Africa. To address this issue, we investigated the effects of dual plastic film and straw mulching in ridge-furrow (RF) system on wheat productivity, soil carbon and nitrogen stocks in a semiarid area in Kenya from 2015 to 2017. The experimental site represents a typical semiarid continental monsoon climate, and soil type is chromic vertisols. Field experiment with randomized block design consisted of six RF treatments as follows: 1) dual black plastic film and straw mulching (RFbS), 2) dual transparent plastic film and straw mulching (RFtS), 3) sole black plastic film mulching (RFb), 4) sole transparent plastic mulching RF (RFt), 5) sole straw mulching (RFS) and 6) no mulching (CK). The results indicated that seasonal dynamics of rainfall and air temperature fit in with the weather type of El Nino over four growing seasons. RFbS, RFtS, RFb and RFt significantly increased soil water storage (SWS), topsoil temperature, aboveground biomass, grain yield and water use efficiency across four growing seasons (p < 0.05) as compared with CK. Among all the treatments, RFbS and RFtS achieved the greatest SWS, AgB, grain yield and WUE, owing to improved soil hydro-thermal status in both treatments. Critically, RFbS and RFtS significantly improved soil organic carbon and total nitrogen, soil bulk density and the C:N ratio following four growing seasons, comparing with other treatments (p < 0.05). Besides, RFbS and RFtS gave the highest economic returns among all treatments. For the first time, we found that dual plastic film and straw mulching could serve as a sustainable land management to boost wheat productivity and improve soil quality under El Nino in semiarid areas of SSA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: To understand the epidemiologic characteristics of endemic typhus in Baoshan city., Methods: Epidemiological data were collected and characteristics were analyzed. IgG antibody (Ab) of Rickettsia mooseri and Orientia tsutsugamushi in serum of patients were tested using both Weil-Felix and IFA method. The Rickettsia mooseri gltA gene, Rickettsia prowazekii gltA gene, Orientia tsutsugamushi 56 kDa protein gene, SFGR ompA gene, Ehrlichia sp. 16S rRNA gene and Anaplasma sp. 16S rRNA gene in spleen of mice were examined by PCR., Results: Fifty-eight endemic typhus cases were found in Longyang district of Baoshan city, during July to August, 2009. Among them, 48 cases were confirmed by clinical diagnosis and 10 cases by laboratory tests. The Ab of Orientia tsutsugamushi Karp serotype was detected in 3 cases from laboratory diagnosis. The spleen samples from 85 Rattus flavipectus were tested using PCR. Of them, 3 samples for Rickettsia mooseri gltA gene showed positive (positive rate was 3.5%), and the homology of 3 Rickettsia mooseri and Rickettsia mooseri Wilmington strain (GenBank U59714.1) was 100% through comparing gene sequence. The results of PCR for detecting Rickettsia prowazekii, Orientia tsutsugamushi, SFGR, Anaplasma sp. and Ehrlichia. sp were all negative., Conclusion: The outbreak of endemic typhus was confirmed in Longyang district of Baoshan city through epidemiological data, clinical diagnosis and laboratory tests. Rickettsia mooseri DNA was detected in the dominant Rattus flavipectus, suggesting that endemic typhus did exist in the local areas.