Effect of burning on selected soil parameters in a grass fallow shifting cultivation system in Bhutan

Grass fallow shifting cultivation is an important land use practice in the highlands of Bhutan. Part of the nutrient pool contained in soil organic matter is made available for the traditional buckwheat (Fagopyrum tataricum) crop through a highly labor intensive system exposing 250–500 MT soil ha⁻¹ to temperatures of 500°C and above. Dry topsoil is collected in mounds and burned using plant biomass or manure and soil organic matter as fuel. Labor input ranged from 150–401 days ha⁻¹ with land preparation accounting for 65–85% of the total requirement. The burning increased soil pH from 6.0 to 6.9 and available K from 34 to 69 mg kg⁻¹. Soil organic C and total N were reduced from 3.3 and 0.17% to 0.8 and 0.08%, respectively. Release of P from soil organic matter and plant material and reduction in C/N ratio resulting in increased N availability are considered the most essential effects required for good crop yields. Through the burning about 16 MT of C and 470 kg N ha⁻¹ are released into the atmosphere. Fallow periods of 15–20 years are required for the system to be sustainable. The research was supported by the Department of Agriculture. Royal Government of Bhuttan and the Swiss Association for Technical Assistance The research was supported by the Department of Agriculture. Royal Government of Bhuttan and the Swiss Association for Technical Assistance     

心肺康复训练联合冬病夏治穴位贴敷对慢性阻塞性肺疾病稳定期患者肺功能、免疫功能和生活质量的影响

摘要 目的：探讨冬病夏治穴位贴敷联合心肺康复训练对慢性阻塞性肺疾病（COPD）稳定期患者免疫功能、肺功能和生活质量的影响。方法：将2021年3月至2022年3月湖北民族大学附属民大医院接收的80例COPD稳定期患者纳为研究对象。按照随机数字表法分为研究组（n=40,接受心肺康复训练联合冬病夏治穴位贴敷）和对照组（n=40,接受心肺康复训练）。对比两组6 min步行试验（6MWT）、COPD急性加重住院次数、住院时间、肺功能、免疫功能和生活质量。结果：研究组治疗后6MWT长于对照组（P<0.05）,研究组的COPD急性加重住院次数少于对照组,住院时间短于对照组（P<0.05）。研究组治疗后咳嗽、睡眠、咳痰、情绪、运动耐力、胸闷、精力和日常运动评分低于对照组（P<0.05）。研究组治疗后CD4⁺、CD4⁺/CD8⁺、免疫球蛋白（Ig）A、IgG、IgM高于对照组,CD8⁺低于对照组（P<0.05）。研究组治疗后用力肺活量（FVC）、呼气峰值流速（PEF）、第1秒用力呼气容积（FEV₁）高于对照组（P<0.05）。结论：冬病夏治穴位贴敷联合心肺康复训练治疗COPD稳定期患者,可有效提高患者的免疫功能和肺功能,提高患者的生活质量。     

Managing native and legume-fixed nitrogen in lowland rice-based cropping systems

Lowlands comprise 87% of the 145 M ha of world rice area. Lowland rice-based cropping systems are characterized by soil flooding during most of the rice growing season. Rainfall distribution, availability of irrigation water and prevailing temperatures determine when rice or other crops are grown. Nitrogen is the most required nutrient in lowland rice-based cropping systems. Reducing fertilizer N use in these cropping systems, while maintaining or enhancing crop output, is desirable from both environmental and economic perspectives. This may be possible by producing N on the land through legume biological nitrogen fixation (BNF), minimizing soil N losses, and by improved recycling of N through plant residues. At the end of a flooded rice crop, organic- and NH₄-N dominate in the soil, with negligible amounts of NO₃. Subsequent drying of the soil favors aerobic N transformations. Organic N mineralizes to NH₄, which is rapidly nitrified into NO₃. As a result, NO₃ accumulates in soil during the aerobic phase. Recent evidence indicates that large amounts of accumulated soil NO₃ may be lost from rice lowlands upon the flooding of aerobic soil for rice production. Plant uptake during the aerobic phase can conserve soil NO₃ from potential loss. Legumes grown during the aerobic phase additionally capture atmospheric N through BNF. The length of the nonflooded season, water availability, soil properties, and prevailing temperatures determine when and where legumes are, or can be, grown. The amount of N derived by legumes through BNF depends on the interaction of microbial, plant, and environmental determinants. Suitable legumes for lowland rice soils are those that can deplete soil NO₃ while deriving large amounts of N through BNF. Reducing soil N supply to the legume by suitable soil and crop management can increase BNF. Much of the N in legume biomass might be removed from the land in an economic crop produce. As biomass is removed, the likelihood of obtaining a positive soil N balance diminishes. Nonetheless, use of legumes rather than non-legumes is likely to contribute higher quantities of N to a subsequent rice crop. A whole-system approach to N management will be necessary to capture and effectively use soil and atmospheric sources of N in the lowland rice ecosystem.IRRI-NifTAL-IFDC joint contribution.     

Characterization of pathogenic bacteria of the cupped oyster Crassostrea gigas

The French mollusc production is mainly based on the Pacific cupped oyster, Crassostrea gigas. Since 1991, outbreaks of mass mortality of juveniles are reported during the summer period. These outbreaks are a major concern of oyster industry. Several studies have established given bacterial strains to be pathogenic for bivalve species, including oysters. Here we present a study of mortality outbreaks of C. gigas, as initiated in 1995. In a first step, bacterial strains were isolated during mass mortality outbreak and were biochemically characterised. Among the isolated strains, some strains of Vibrio splendidus biovar II were found to be pathogenic by means of experimental challenge of oyster juveniles. In the second step, a genotypical identification of the pathogenic strain was undertaken, based on 16S RNA sequences and phylogenetic analysis. It confirmed that the pathogenetic strain belonged to Vibrio splendidus biovar II.     

Molecular insights into the neutrophils activation in zebu cattle during seasonal variation

Earlier, we reported the impact of season on neutrophils’ functional competence and also hypothesized that it could be the impact of different seasons on neutrophils’ activation. In cerebration, the present study aimed to provide insights into neutrophils’ activation in terms of phosphorylation of tyrosine containing proteins during different seasons. Ten Hariana cows participated in the study and eight times blood samples were collected from each animal (twice in each month) during each season. Phosphorylation of tyrosine proteins was evaluated using western blotting and immunolocalization using a fluorescent microscope. Immuno blotting identified six tyrosine-phophorylated proteins p28, p42, p44, p58, p84, and p104 in winter and rainy seasons, whereas, p84 protein was absent in summer season. Immunolocalization revealed positive immune reactivity (IR) for tyrosine-phosphorylated proteins and significantly (p < 0.05) lower percent of neutrophils showed positive IR during the summer season as compared to winter and rainy seasons. The results of the study evidently indicate the activation of neutrophils is mediated through tyrosine phosphorylation and this may be a probable reason behind the decreased neutrophils’ functional competence during the summer. Further studies are warranted to decipher the possible association between tyrosine phosphorylation and expression of surface receptors required for the recruitment of neutrophils.     

Mountain goat survival in coastal Alaska: Effects of age,sex, and climate

Ecological theory predicts that individual survival should vary between sex and age categories due to differences in allocation of nutritional resources for growth and reproductive activities. During periods of environmental stress, such relationships may be exacerbated, and affect sex and age classes differently. We evaluated support for hypotheses about the relative roles of sex, age, and winter and summer climate on the probability of mountain goat (Oreamnos americanus) survival in coastal Alaska. Specifically, we used known-fates analyses (Program MARK) to model the effects of age, sex, and climatic variation on survival using data collected from 279 radio-marked mountain goats (118 M, 161 F) in 9 separate study areas during 1977–2008. Models including age, sex, winter snowfall, and average daily summer temperature (during Jul–Aug) best explained variation in survival probability of mountain goats. Specifically, our findings revealed that old animals (9+ yr) have lower survival than younger animals. In addition, males tended to have lower survival than females, though differences only existed among prime-aged adult (5–8 yr) and old (9+ yr) age classes. Winter climate exerted the strongest effects on mountain goat survival; summer climate, however, was significant and principally influenced survival during the following winter via indirect effects. Furthermore, old animals were more sensitive to the effects of winter conditions than young or prime-aged animals. These findings detail how climate interacts with sex and age characteristics to affect mountain goat survival. Critically, we provide baseline survival rate statistics across various age, sex, and climate scenarios. These data will assist conservation and management of mountain goats by enabling detailed, model-based demographic forecasting of human and/or climate-based population impacts. © 2011 The Wildlife Society.     

种植密度对北疆复播大豆光合特性及产量的影响

以大豆品种‘黑河43’为材料,于2012和2013年连续2年进行5种不同种植密度——37.5(A)、45.0(B)、52.5(C)、60.0(D)和67.5万株·hm-2(E)的田间复播试验,研究滴灌条件下密度对大豆功能叶叶绿素值(SPAD)、叶面积指数(LAI)、比叶面积(SLA)、大豆光合特性及产量构成因素的影响。结果显示:(1)密度对复播大豆苗期叶片SPAD值影响较小,苗期之后处理间差异显著,且整个生育期SPAD值均随着密度的增加而增大。(2)LAI在2年试验中均随着密度的增加而增大,均在鼓粒期左右达到峰值,处理E在2012年和2013年的最大值分别为6.24和5.56,较同期最低的处理A分别显著提高18.41%和36.17%;SLA随着密度的增加而增大,且在生长发育前期和后期处理间差异明显,中期差异相对较小。(3)叶片的净光合速率(Pn)、蒸腾速率(Tr)及气孔导度(Gs)均随着密度的增加而先增后降,且均以C处理最高,Pn、Gs在结荚期达到极值,而Tr在开花期最大;胞间CO2浓度(Ci)随着密度的增加呈现出先降后增的趋势,2012年和2013年均以C处理最低,分别为185.70和179.61μmol·mol-1。(4)各处理2年的籽粒产量均以中等密度的C处理达最高,2012年和2013年分别为3 205.0和3 142.53kg·hm-2,并分别比同年的其余处理显著高出1.42%~14.26%和1.08%~27.65%。研究表明,适宜密度的复播大豆不仅有较高的叶绿素含量,有利于群体对光能的利用,同时具有适宜的叶面积指数而不致植株郁闭,有效保证了群体内部与外界的气体交换,提高了光合速率和籽粒产量。     

20世纪初以前西方学者对中国冬虫夏草的记载和研究

冬虫夏草在中国是一种著名的药材。最早记录它的文献是15世纪的藏医籍《千万舍利》。随着法国传教士巴多明(Parennin)于1723年将冬虫夏草标本从北京寄往法兰西科学院,西方学术界开始了对这种中国药材的认识和研究历程。在1841年英国昆虫学家韦斯特伍德(Westwood)开始鉴定这种真菌以前,西方学者认为冬虫夏草的真菌子实体是植物的根。此后,英国真菌学家贝克莱(Berkeley)分别在1843和1856年将其定名为"Sphaeria Sinensis"和"Cordyceps sinensis"。但是为学界广泛使用并沿用至今的,却是意大利植物学家萨卡多(Saccardo)在其1883年的专著中为冬虫夏草的定名"Cordyceps sinensis(Berk.)Sacc."。在20世纪初以前,西方人对中国冬虫夏草的记录和描述具有多重价值,对于了解中国冬虫夏草的使用历史而言是重要的补充资料。     

Aestivation in Pieris brassicae (L.) affects the parasitoid load caused by Cotesia glomerata (L.)

The large white butterfly Pieris brassicae (L.) (Lepidoptera: Pieridae) undergoes a unique aestivation in southern Spain. Its pupae remain dormant for three months in summer, emerging in early September. Its main parasitoid, Cotesia glomerata (L.) (Hymenoptera: Braconidae), shows no such diapause behavior and is thus deprived of its main host for this period and has to switch to less suitable host species. To study the effect the aestivation has on the parasitoids, caterpillars were collected from the region in May and September and levels of parasitization were determined. Results show that parasitoid attacks decrease clearly after the summer diapause. The number of parasitized butterfly clutches in September was only one third as the number in May and the infestation rate of an attacked clutch decreased by 55% after aestivation. The distribution of brood sizes of C. glomerata showed clear signs of superparasitism before but not after the diapause. Therefore, the butterfly generation after summer diapause has to deal with distinctly diminished numbers of parasitoids. This increases the survival rate of the caterpillar and thus improves the fitness of the butterfly.