Fecal microbiota dynamics and its relationship to diarrhea and health in dairy calves

Background:Diarrhea is a major cause of morbidity and mortality in young calves,resulting in considerable economic loss for dairy farms.To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning,we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials,with the first trial having 14 Holstein dairy calves whose fecal samples were collected 18 times over 78 d from birth to 15 d post-weaning and the second trial having 43 Holstein dairy calves whose fecal samples were collected daily from 8 to 18 days of age corresponding to the first diarrhea peak of trial 1.Results:Metataxonomic analysis of the fecal microbiota showed that the development of gut microbiota had three age periods with birth and weaning as the separatrices.Two diarrhea peaks were observed during the transition of the three age periods.Fusobacteriaceae was identified as a diarrhea-associated taxon both in the early stage and during weaning,and Clostridium_sensu_stricto_1 was another increased genus among diarrheic calves in the early stage.In the neonatal calves,Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),and Alloprevotella(ASV14)were negatively associated with Clostridium_sensu_stricto_1(ASV48),the keystone taxa of the diarrhea-phase module.During weaning,unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Barnesiella(ASV497),and Ruminococcaceae_UCG-005(ASV254)were identified being associated with non-diarrheic status,and they aggregated in the non-diarrhea module of co-occurrence patterns wherein unclassified Muribaculaceae(ASV28)and Barnesiella(ASV497)had a direct negative relationship with the members of the diarrhea module.Conclusions:Taken together,our results suggest that the dynamic successions of calf gut microbiota and the interactions among some bacteria could influence calf diarrhea,and some species of Prevotella might be the core microbiota in both neonatal and weaning calves,while species of Muribaculaceae might be the core microbiota in weaning calves for preventing calf diarrhea.Some ASVs affiliated with Prevotella_2(ASV4 and ASV26),Prevotella_9(ASV43),Alloprevotella(AVS14),unclassified Muribaculaceae(ASV28 and ASV44),UBA1819(ASV151),Ruminococcaceae_UCG-005(ASV254),and Barnesiella(ASV497)might be proper probiotics for preventing calf diarrhea whereas Clostridium_sensu_stricto_1(ASV48)might be the biomarker for diarrhea risk in specific commercial farms.

Microglial dynamics during brain development

Microglia are the resident immune cells of the central nervous system （CNS）, In the normal state, microglia have a ramified shape and con- tinuously survey the conditions of the brain.

Study on Dynamic Characteristics of the Growth and Development of Armeniaca dasycarpa(Ehrh.) Borkh

[ Objective] This study aimed to analyze the dynamics of growth and development of Armeniaca dasycarpa （ Ehrh. ） Borkh fruit, thus providing the the- oretical basis for cultivation and breeding of good-quality and high-yield A. dasycarpa. [ Method] With A. dasycarpa cultivar Yechengzixing as the experimental material, P. cerasifera Ehrh cultivar Huangguoyingtaoli and A. vulgaris Lam. cultivars Luopuhongdaike, Wanshujianali and Kuchetuoyong as control, the vertical diameter, horizontal diameter and fresh weight of fruit and embryos were measured every 7 d during the growth and development period. [ Result] The result showed that the whole fruit growth period of Yechengzixing, lasted 93 d from the end of flowering to fruit maturity. The dynamics of fruit vertical diameter, horizon- tal diameter and fresh weight of Yechengzixing presented ＂rapid-slow-rapid＂ double S-shaped curves. The whole fruit growth period of Yechengzixing could be di- vided approximately into three stages： first rapid growth stage, slow growth stage and second rapid growth stage, which lasted 29, 42 and 21 d, respectively. Daily increment of fruit vertical diameter and horizontal diameter of Yechengzixing reached the maximum at the first rapid growth stage, while daily increment of fruit fresh weight reached the maximum at the second rapid growth stage. The dynamics of vertical diameter, horizontal diameter and fresh weight of Yechengzixing embryos presented S-shaped curves. Fruit growth and development dynamics of the tested materials presented double S-shaped curves. The whole fruit growth period of Yechengzixing, Huangguoyingtaoli and three apricot cuhivars lasted 93, 119 and 77 -98 d, respectively. Thus, the duration of fruit growth period of Yechengzixing was 26 d shorter than that of Huangguoyingtaoli and exhibited no significant difference compared with three apricot cultivars. The duration of each growth stage and daily increment of Yechengzixing fruit had no significant difference compared with three apricot cultivars. Moreover, Huangguoyingtaoli had a longer slow growth stage and lower daily increment than Yechengzixing. [ Conclusion] The whole fruit growth period, duration of each growth stage and daily increment of Yechengzix- ing exhibited no significant difference compared with three apricot cultivars but varied remarkably compared with Huangguoyingtaoli.

Analyses of the Temporal Development and Yield Losses due to Sheath Blight of Rice (Rhizoctonia solani AG1.1a)

Sheath blight of rice, caused by Rhizoctonia solani AG 1. 1a, has become the most important disease and caused serious yield losses in some major rice-growing regions in China in recent years. In the present study, field plot experiment was conducted to examine the relationships between disease intensity and inoculum density （ID）, the seasonal disease epidemic dynamics, and yield reductions due to disease damages. Results from the experiment demonstrated that the areas under progress curves of disease severity and those of percent rice tillers diseased were positively and closely related to the relative initial ID of the pathogen. The inoculum density-disease （IDD） relationships were simulated and the impractical linear models were obtained. Both logistic and Gompertz functions could be used to simulate the disease progress dynamics in time, but the progress curves of the disease severity were modeled better by the Gompertz than by logistic function. However, the Richards function was found to be the best in simulating the disease progress curves when a most appropriate value was chosen for the shape parameter m by using the computer software Epitimulator. Sheath blight infection decreased rice yield very significantly and a yield reduction of 40% was recorded in rice crop with the highest inoculum density. Rice yield was linearly and negatively correlated with the disease severity and the percent tillers affected. The simulated models for all these relationships were computed through executing Epitimulator software and were presented in this paper.

Analysis of blasting damage in adjacent mining excavations

Following a small-scale wedge failure at Yukon Zinc＇s Wolverine Mine in Yukon, Canada, a vibration monitoring program was added to the existing rockbolt pull testing regime. The failure in the 1150 drift occurred after numerous successive blasts in an adjacent tunnel had loosened friction bolts passing through an unmapped fault. Analysis of blasting vibration revealed that support integrity is not compromised unless there is a geological structure to act as a failure plane. The peak particle velocity（PPV） rarely exceeded 250 mm/s with a frequency larger than 50 Hz. As expected, blasting more competent rock resulted in higher PPVs. In such cases, reducing the round length from 3.5 m to 2.0 m was an effective means of limiting potential rock mass and support damage.

Numerical Analyses of Caisson Breakwaters on Soft Foundations Under Wave Cyclic Loading

A caisson breakwater is built on soft foundations after replacing the upper soft layer with sand. This paper presents a dynamic finite element method to investigate the strength degradation and associated pore pressure development of the intercalated soft layer under wave cyclic loading. By combining the undrained shear strength with the empirical formula of overconsolidation clay produced by unloading and the development model of pore pressure, the dynamic degradation law that describes the undrained shear strength as a function of cycle number and stress level is derived. Based on the proposed dynamic degradation law and M-C yield criterion, a dynamic finite element method is numerically implemented to predict changes in undrained shear strength of the intercalated soft layer by using the general-purpose FEM software ABAQUS, and the accuracy of the method is verified. The effects of cycle number and amplitude of the wave force on the degradation of the undrained shear strength of the intercalated soft layer and the associated excess pore pressure response are investigated by analyzing an overall distribution and three typical sections underneath the breakwater. By comparing the undrained shear strength distributions obtained by the static method and the quasi-static method with the undrained shear strength distributions obtained by the dynamic finite element method in the three typical sections, the superiority of the dynamic finite element method in predicting changes in undrained shear strength is demonstrated.

On Dynamic Social Factors for Development of China’s Human Rights Theory

China＇s mainstream human rights theory has undergone tremendous changes since the reform-and-opening scheme was kicked off in the early 1980s. ＂Human rights,＂ which used to be seen as a concept of capitalist ideology, is now an important part of the Chinese system of socialist values.

Investigation of time dependent development of soil structure and formation of macropore networks as affected by various precrop species

A well developed macropore network is advantageous in terms of transport processes regarding gas and water,as well as nutrient acquisition and root growth of crops.X-ray computed tomography provides a non-destructive method to visualize and quantify three-dimensional pore networks.Geometrical and morphological parameters of the complex pore system such as connectivity,tortuosity,porosity and pore surface area would be very useful for modeling and simulation of transport and exchange processes by providing quantitative data on relevant soil structural features and their modification by soil management.The scope of this study was to analyze and quantify the development of soil structure in the subsoil depending on three different precrop species(alfalfa A,chicory C and fescue F),at three depths(45,60 and 75 cm)and cultivation periods(1,2 and 3 years).Furthermore,morphological(air-filled porosityθa,pore surface area)and geometrical(pore diameter,connectivity,continuity,tortuosityτ)parameters were gathered with X-ray CT and image analysis.From an experimental field trial(Germany)with a Haplic Luvisol as soil type samples were taken and investigated.Air-capacity(θa)was measured in the laboratory for the same cylinders and compared to the results derived by image analysis.Air-capacity was highest for alfalfa(3 years,75 cm).Tortuosity(τ)ranged between 1.3 and 4.38,while alfalfa(3 years)showed the highest value,which indicated structural development due to crack formation by enhanced root water uptake.Thus,an increase in accessible surface may improve water and nutrient supply for plants,whereas the highτvalues may assume that oxygen supply is limited.It was found that the interaction of gas-diffusivity and the calculated parameters should be further investigated in terms of limitations to plant growth.

Development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen forest in eastern China

Abstract The aim of this work was to understand the development of defoliating insects and their preferences for host plants under varying temperatures in a subtropical evergreen broad-leaved forest in China. We measured the main developmental parameters of three typical defoliating insects （i.e., Ourapteryx ebuleata szechuana, Biston marginata, and Euproctis angulata） and their preferences for five host plants at temperatures from 16~C to 31 ~C at 3~C intervals in the Tiantong National Forest Research station in eastern China. The results showed the following. 1） An appropriate rise in temperature increases the survival rate with an increase in the number of offspring. The developmental durations for these three insects were shortened, and pupal weight increased with an increase in temperature. 2） A shift in the preference for host plants for these three insects was observedat elevated tempera- tures. They all preferred to feed on Schima superba and Castanopsis sclerophylla at elevated temperatures, show- ing an opposite response to the other three plants. The daily leaf consumption of the three insects was positively correlated with their feeding preference, with more leaves being consumed from the plants they preferred. 3） For O. ebuleata szechuana larvae, daily leaf consumption initially increased and then decreased with increasing temperatures. In contrast, Biston marginata and Euproctis angulata larvae consumed more leaves at elevated temperatures. The feeding preferences of O. ebuleata szechuana and Biston marginata were more sensitive to changing temperatures than that of Euproctis angulata laevae. We concluded that increased numbers of offspring and generations, pupal weights, and a shift in preference to two plants for these three defoliating insects might lead to severe damage to these two plants which would enhance the fragmentation and decrease the stability of the forest communities under changing temperatures. Meanwhile, the variations in the responses of defoliating insects to the changing temperatures should be taken into consideration for the pest management of forests to adapt to the changing climate.

What We Measure Matters:The Case of the Missing Development Data in Sendai Framework for Disaster Risk Reduction Monitoring

The Sendai Framework for Disaster Risk Reduction 2015−2030’s(SFDRR)framing moved away from disaster risk as a natural phenomenon to the examination of the inequality and injustice at the root of human vulnerability to hazards and disasters.Yet,its achievements have not seriously challenged the long-established capitalist systems of oppression that hinder the development leading to disaster risk creation.This article is an exploratory mapping exercise of and a collective reflection on Sustainable Development Goals(SDGs)and SFDRR indicators-and their use in measuring progress towards disaster risk reduction(DRR).We highlight that despite the rhetoric of vulnerability,the measurement of progress towards DRR remains event/hazard-centric.We argue that the measurement of disaster risk could be greatly enhanced by the integration of development data in future iterations of global DRR frameworks for action.

On the Dynamic Model of the Development of Urban Business Center System

The static model applied nowadays in the planning of urban business center systemin China can no longer meet the requirements of modern urban construction. The authoradopted the dynamic model to study the activity pattern of the Nanjing residents who didshopping in the business center and as well the development law of the center itself, hop-ing to find out an effective planning approach for business center system.