A1∑＋ State Lifetime and Predissociation of Cull

A combined cavity ringdown （CRD） and laser induced fluorescence （LIF） spectroscopic study on the A1∑＋-X1∑＋ transition of Cull has been presented. The Cull molecule, as well as its deuterated isotopologue CuD, are produced in a supersonic jet expansion by discharging H2 （or D2） and Ar gas mixtures using two copper needles. Different profiles of relative line intensities are observed between the measured LIF and CRD spectra, providing an experimental evidence for the predissociation behavior in the A1∑＋ state of Cull. The lifetimes of individual upper rotational levels are measured by LIF, in which the J＇-dependent predisso- ciation rates are obtained. Based on the previous theoretical calculations, a predissociation mechanism is concluded due to the strong spin-orbit coupling between the A1∑＋ state and the lowest-lying triplet 3∑＋ state, and a tunneling effect may also be involved in the predis- sociation. Similar experiments are also performed for CuD, showing that the A1∑＋ state of CuD does not undergo a predissociation process.

Analysis of the lifetime and culling reasons for AI boars

Background: The aim of the study was to analyze the lifetime and culling reasons for boars used in insemination centers(AI centers).Methods: The data collected from 355 culled boars from 1998 to 2013 included: age at start of semen collection,boar herd life, culling reason, daily gain and lean meat content, and number of ejaculates not meeting sales requirements after dilution. Culling reasons were divided into 7 groups: low semen value(LSV), low or lack of libido(LL), leg problems(LP), infectious diseases(ID), old age(OA), reduced demand for semen from the given boar(RD),and others(OT).Results: The most common culling reasons for boars were LSV(23.7%) and RD(22.5%). It was observed that the lowest daily gains were noted in boars culled due to OA. Boars culled due to OA and RD were maintained in production for the longest time(over 1000 d), for LSV and ID retention was about 700 d, and due to LL below 400 d. The survival probability was over 0.9 until 1.5 yr, and just over 0.2 until 4 yr. The highest relative frequency was observed in the 36 ^(th) and 42 ^(nd) mo of life(over 16%). Hazard risk analysis revealed a more than 10 times higher risk of culling in the case of LL, ID or OT, in comparison to OA.Conclusions: The results can be used as a direct point of reference for the identification of emerging problems in AI boar exploitation and the development of an appropriate culling policy in AI centers.

Impact of Vaccination and Culling on Controlling Foot and Mouth Disease: A Mathematical Modelling Approach

Foot and mouth disease (FMD) is a major threat, not only to countries whose economies rely on agricultural exports, but also to industrialized countries that maintain a healthy domestic livestock industry by eliminating major infectious diseases from their livestock populations. In this paper a simple mathematical model is formulated and comprehensively analyzed to assess the impact of vaccination and culling on controlling FMD. Overally the study demonstrates that vaccination and culling are essential on controlling FMD if they are all implemented. Furthermore the study illustrates that culling latently infected (early detection of infected animals) is extremely important on controlling FMD dynamics.

cull小议

近来有关禽流感的报道中经常用Ncun这个词，词典给cull下的定义是“为了减少或者限制数量，剔除动物，尤其是那些弱者”。cull这个词起源于拉丁语，然后进入法语，成了colligere，意思是“绑在一起”；从法语进入了英语，成了cull，原义是“选择植物或者砍伐树”，引申为“

Visibility Culling Algorithm with Hierarchical Adaptive Bounding Setting

Hierarchical adaptive bounding setting （HABS）, a novel algorithm to reduce potentially visible set, is designed to be Used for various geometry shape character in complex simulation scene to greatly improve geometry spatial storage precision. A spatial hierarchy tree is used to represent the topology of the model, and then the visibility geometry set from the viewpoint is determined by processing the hierarchy tree and frustum detection. In this process, HABS improves the viewpoint-to-region visibility detection efficiently. The algorithm is well-suited for complex models whose shape characters are various.

Occlusion Culling Algorithm Using Prefetching and Adaptive Level of Detail Technique

A novel approach that integrates occlusion culling within the view-dependent rendering framework is proposed. The algorithm uses the prioritized-layered projection（PLP） algorithm to occlude those obscured objects, and uses an approximate visibility technique to accurately and efficiently determine which objects will be visible in the coming future and prefetch those objects from disk before they are rendered, view-dependent rendering technique provides the ability to change level of detail over the surface seamlessly and smoothly in real-time according to cell solidity value.

Productive Performance of Double-Muscled Piemontese Culled Cows in Finishing Period

The aims of the study were to evaluate productive performances and environmental impact of double-muscled Piemontese culled cows. In two trials, 39 Piemontese culled cows aged from 46 to 176 mon were fattened using diets commonly applied in farm conditions. The animals were weighed at the beginning and end of the trials. Concentrate and hay intake were recorded daily. After slaughtering, meat, fat and bone yields were recorded and dressing percentage was calculated. The backward linear regression model was employed for statistical analysis. Results showed average body weight （ABW） of cows as （556.97± 55.99） kg and relatively low dry matter intake （DMI） [（9.17± 0.35） kg d^-1] during the fattening period. The ratio between DMI and ABW, i.e., ratio between intake and weight （RIW）, （1.66±0.18）% was negatively influenced by initial body weight （IBW） and duration of finishing period （D）, but age had no effect on RIW. Average daily gain （ADG） was relatively low [（0.55 ±0.21） kg d^-1, and was negatively correlated with IBW and D, which implied that lower IBW and shorter D could have higher ADG and vice versa. The dressing percentage （DP） was （59.80± 1.83）% and the carcass red meat yield （MY） was （75.17±3.10）%. Nevertheless, N efficiency was very low [（4.35 ± 1.76）%], which must be considered in relation to environmental protection so both animal requirements and a well balanced diet need more attention. In conclusion when Piemontese cows will be culled and fattened, IBW and D should be considered carefully in order to get a reasonable ADG and N efficiency to guarantee productive benefits and environmental protection at the same time.

Spatiotemporal changes in antlerless proportion of culled Sika deer in relation to deer density

Population management of herbivores is widely applied to decrease damage to forests in the northern hemisphere. Culling more antlerless deer, including females and fawns, is an effective means of reducing the population and helps to improve management efficiency. To increase the efficiency of antlerless-biased culling, we assessed the spatiotemporal distribution of the antlerless ratio in culled sika deer (Cervus nippon) in relation to population density. We hypothesized that the antlerless ratio is higher at the center of the distribution than at the margins of the deer’s range, because dispersal processes differ according to sex and age: Young male deer first disperse into an unoccupied area, and then males may become established in the new area for approximately 10–15 years before the number of females increases. A statistical model revealed spatiotemporal changes in the antlerless ratio of culled sika deer. The change in the ratio basically fit the density distribution of the deer, which was estimated independently on the basis of fecal pellet count surveys. The antlerless ratio estimated from the model increased asymptotically as deer density rose. The results support our hypothesis and suggest that antlerless sika deer will be more easily culled at the center rather than at the margins of the distribution range. These findings should help to increase the efficiency of managing the deer via antlerless-biased culling.

Optimal design of culling compensation policy under the African swine fever——Based on simulations of typical pig farms in China

This paper aims to optimize the culling compensation policy from a micro perspective through scenario simulation.Based on an investigation of 273 pig farms in eight regions,four typical pig farms were constructed according to farm size and breeding mode,representing the swine producers in China.Besides,a decision objective function of pig farms facing suspected African swine fever(ASF)outbreaks was constructed.This study used a mathematical programming model to design and simulate scenarios based on compensation standards and local implementation levels,aiming to incentivize pig farms to report epidemics.The results show that the optimal decisions on epidemic reports differed among typical farms and by herd daily age.The results suggest the following adjustments for optimizing culling compensation policies:(1)to set culling compensation standards based on the market value and(2)to maintain a high level of epidemic surveillance capability in the animal husbandry and veterinary sector.

3D Model Occlusion Culling Optimization Method Based on WebGPU Computing Pipeline

Nowadays,Web browsers have become an important carrier of 3D model visualization because of their convenience and portability.During the process of large-scale 3D model visualization based on Web scenes with the problems of slow rendering speed and low FPS(Frames Per Second),occlusion culling,as an important method for rendering optimization,can remove most of the occluded objects and improve rendering efficiency.The traditional occlusion culling algorithm(TOCA)is calculated by traversing all objects in the scene,which involves a large amount of repeated calculation and time consumption.To advance the rendering process and enhance rendering efficiency,this paper proposes an occlusion culling with three different optimization methods based on the WebGPU Computing Pipeline.Firstly,for the problem of large amounts of repeated calculation processes in TOCA,these units are moved from the CPU to the GPU for parallel computing,thereby accelerating the calculation of the Potential Visible Sets(PVS);Then,for the huge overhead of creating pipeline caused by too many 3D models in a certain scene,the Breaking Occlusion Culling Algorithm(BOCA)is introduced,which removes some nodes according to building a Hierarchical Bounding Volume(BVH)scene tree to reduce the overhead of creating pipelines;After that,the structure of the scene tree is transmitted to the GPU in the order of depth-first traversal and finally,the PVS is obtained by parallel computing.In the experiments,3D geological models with five different scales from 1:5,000 to 1:500,000 are used for testing.The results show that the proposed methods can reduce the time overhead of repeated calculation caused by the computing pipeline creation and scene tree recursive traversal in the occlusion culling algorithm effectively,with 97%rendering efficiency improvement compared with BOCA,thereby accelerating the rendering process on Web browsers.

Physical Conditions of Cull Sows Associated with On-Farm Production Records

Cull sow physical conditions were associated with on-farm production records. Sows (923) within one integrated U.S. production system were evaluated at two harvest facilities. Physical conditions evaluated at harvest were analyzed by parity, culling code and production measures. Farm culling codes were categorized into poor body condition (BC), old age (G), lameness (L), other (O), poor litter performance (P) and reproductive failure (R). Production measures included lifetime pigs born alive (LPBA), pigs born alive in the last litter (PBALL), pigs per sow per year (PSY) and weaning to culling interval. The L culling code had a greater (P < 0.05) prevalence of cracked hooves when compared to the other five culling codes (30.9% vs. 18.7%). Sows without front cracked hooves tended (P = 0.07) to have greater PSY (0.80) when compared to sows having front cracked hooves. Females without rear digital overgrowth had more (P < 0.05) PBALL (0.54) and tended (P = 0.06) to have increased PSY (0.80) when compared to sows with rear digital overgrowth. Sows without shoulder lesions had greater (P < 0.05) LPBA (2.01) when compared to sows with shoulder lesions. Regression coefficient estimates for percent lung lesion involvement were positive and tended (P < 0.10) to be different from zero for LPBA (0.06) and PSY (0.03). Females with severe teeth wear tended (P ≤ 0.10) to have fewer LPBA (1.36), PBALL (0.45) and had fewer (P < 0.01) PSY (1.10) when compared to sows without severe teeth wear. Sows culled for BC and L had lower (P < 0.01) backfat when compared to sows from the other four culling codes (1.83 and 2.04 cm vs. 2.47 to 2.85 cm, respectively). Multiple cull sow physical conditions evaluated at harvest had associations with on-farm reproductive measures.

人乳头瘤病毒16E7和CulL2依赖蛋白对APOBEC3A蛋白表达及子宫颈细胞迁徙能力的影响

人乳头瘤病毒(Human papillomavirus,HPV)16 E7基因编码多功能磷酸蛋白,其功能和结构均类似腺病毒,HPV 16 E7可与激活的致癌基因结合,促进肿瘤进展。但是HPV 16 E7对子宫颈细胞迁移的影响和机制尚不清楚。因此本研究探究了HPV16 E7和CulL2依赖蛋白对APOBEC3A蛋白表达及子宫颈细胞迁徙能力的影响。随机选择60名年龄在21～55岁间的妇女,分别设置空白对照组(B组)、患有人乳头瘤细胞组(P组)、添加CulL2依赖蛋白组(C组),采用流式荧光杂交法和第二代杂交捕获实验(hc2)检测其子宫颈脱落细胞,进行细胞培养,采用Transwell法检测细胞数,重组质粒DNA分析基因克隆的完整性,代谢标记细胞,进行过氧化氢酶(catalase,CAT)分析。采用实时荧光定量PCR法对CulL2和APOBEC3A基因水平进行评估测定,免疫印迹(Western Blot,WB)检测相关蛋白表达。与B组相比,P组细胞穿透基质胶的细胞数增多,即迁徙能力提高,重组质粒转染后,C组细胞穿透基质胶的细胞数亦明显增多,但增多幅度不如P组,即迁徙能力有所增强(P<0.05)。高风险HPV蛋白E7可上调细胞中APOBEC3A蛋白的表达。APOBEC3A和HPV16 E7与CulL2相互作用,表明在HPV感染期间形成的E7可调节细胞中的APOBEC3A蛋白的水平。反转录PCR(Reverse transcription-PCR,RT-PCR)结果显示,与B组比较,P组细胞基因表达增加,C组细胞中CulL2和APOBEC3A基因的mRNA表达水平明显减少(P<0.05)。本研究发现HPV16 E7和CulL2依赖蛋白可影响APOBEC3A蛋白表达,并且促进子宫颈细胞的迁徙能力。

Unwanted and unintended effects of culling: A case for ecologically-based rodent management

In this study, the ecological effects of culling programs are considered in the context of rodent pest management.Despite the escalation of rodent problems globally, over the past quarter of a century there have not been many newdevelopments in culling programs directed at managing these populations. There is a strong reliance on broad scaleuse of chemical rodenticides or other lethal methods of control. The ecological consequences of culling programsbased on chemical rodenticides and bounty systems are considered. Although rodents cause tremendous economichardship to people on a continental scale, usually less than 10% of species cause substantial impacts. Indeed, manyspecies of rodent provide important “ecological services” and, given that culling programs rarely distinguishbetween rodent species, often the non-pest rodents are at grave risk. Rodent control is conducted with littleappreciation of what proportion of the population would need to be culled for a significant reduction in economicdamage. In Indonesian rice fields, once rodent densities are high then a reduction in yield loss from 30% to 15%would require more than 75% of the population to be culled;a reduction to less than 5% yield loss would requiremore than a 95% cull. The negative ecological consequences of culling can be better managed if the method isspecifically tailored to the species that need to be managed. A greater emphasis on ecologically-based rodentmanagement would assist markedly in reducing the unwanted and unintended effects of culling.

通过包络面重构的大规模粒子并行绘制算法

针对大规模粒子高表现可视化需求,提出基于包络面重构的大规模粒子并行绘制算法。该算法以连续曲面的形式表示,绘制大规模粒子的团簇表面及其物理量分布。对算法进行了分布式并行化,从而可以通过大规模并行来处理亿以上规模的粒子数据。在算法实现上,还解决了并行计算时的块间裂缝问题,并提出了快速查找邻域粒子的方法,同时,基于可见性对粒子数据进行剔除,提高了绘制效率。由此,可以通过带光照效果的光滑曲面来高表现展示大规模粒子数据中的团簇结构及其物理量分布。实验结果表明,该算法在512核上可在5 s内完成上亿粒子的绘制,并行效率可达60%。该算法已成功应用到大规模并行非平衡分子动力学模拟等实际模拟应用中。

不同紫苏原料对贵州黑山羊血清抗氧化酶活性、瘤胃发酵参数、瘤胃微生物区系的影响

试验旨在分析不同紫苏原料对贵州黑山羊淘汰母羊瘤胃发酵参数、血清抗氧化酶活性、瘤胃微生物区系的影响,为开发紫苏及其副产物作为饲料资源在黑山羊淘汰母羊育肥中的应用提供技术支撑。选取32只年龄、体况相近的贵州黑山羊,随机分为1个对照组和3个处理组,饲喂不同全混合日粮颗粒饲料,分别为对照组(CK组)、紫苏秸秆组(S_(1)组)、紫苏饼粕组(S_(2)组)及紫苏种子组(S_(3)组),预试期14 d,试验期60 d,每30 d测定一次体重,试验结束后采集血液、瘤胃液,用于测定血清抗氧化酶活性、瘤胃发酵参数以及瘤胃微生物区系。结果显示:添加不同紫苏组分处理都能显著增加淘汰母羊育肥前期(0~30 d)日增重(P<0.05),其中S_(3)组增重最大,其次为S_(2)和S_(1)组;而育肥后期各组日增重差异不显著(P>0.05)。其次,S_(1)和S_(3)组均能显著提高血清样品超氧化物歧化酶活性(SOD)和丙二醛(MDA)含量(P<0.05),而过氧化氢酶(CAT)活性和总抗氧化能力(T-AOC)含量在各组间表现各不相同(P>0.05)。添加紫苏组分的试验组均能显著降低乙酸含量(P<0.05),丙酸、丁酸、异丁酸、戊酸、异戊酸和总挥发性脂肪酸含量在S_(2)、S_(3)和CK组中差异不显著(P>0.05),而在S_(1)组中相应有机酸含量均显著低于CK组(P<0.05)。氨态氮的含量在各组别间差异不显著(P>0.05)。通过高通量测序分析瘤胃微生物区系发现,不同处理对瘤胃微生物种类没有显著影响,而反应相同微生物物种丰度的Chao1指数和ACE指数在S_(1)与S_(3)间表现不相同,其中Chao1指数差异显著(P=0.047),而ACE指数差异不显著(P=0.062)。OTU检出S_(1)组>S_(2)组>CK组>S_(3)组,从门水平分析各试验组优势菌群丰度,各试验组优势菌群主要为厚壁菌门、拟杆菌门和变形菌门微生物,其中S_(2)和S_(3)组中厚壁菌门、拟杆菌门丰度总和略高于CK组,S_(1)、S_(2)和S_(3)组中变形菌门的丰度均低于CK组;属水平分析各试验组优势菌群主要为普雷沃氏菌属、奎因氏菌属、琥珀酸弧菌属以及不可培养的瘤胃微生物菌属,其中S_(1)、S_(2)和S_(3)组中不可培养瘤胃微生物丰度高于CK组。其余微生物丰度在各试验组中各不相同。上述结果表明,添加不同紫苏组分能够不同程度改善淘汰母羊前期育肥效果,以添加紫苏籽效果最佳,其原因可能是通过增加血清抗氧化能力、调节淘汰母羊对粗纤维和非纤维性碳水化合物的消化能力及调控瘤胃微生物区系的组成,进而改善淘汰母羊的育肥效果。

基于Web3D的车间可视化系统设计与实现

针对当前三维可视化系统中存在的渲染速度慢、渲染效率低等问题,引入视锥体剔除渲染算法,基于Web3D技术设计了可视化车间系统。该系统采用B/S框架,利用Three.js技术实现场景的3D加载,实现了在浏览器上进行虚拟化仿真模拟。使用八叉树和轴对称包围盒的视锥体剔除渲染算法,提高了三维场景的渲染速度。并通过综合车间的实际验证,实现了车间设备的工作状态实时监控,生产数据展示更加立体、直观,有效提升了车间可视化系统运行效率和交互性能,满足了现代化车间的管理需求。

基于多策略融合灰狼算法的移动机器人路径规划

针对标准灰狼算法(GWO)在解决移动机器人路径规划问题时存在初始参数依赖性强、缺乏多样性及易陷入局部极值的缺陷,提出一种基于多策略融合灰狼算法(LTGWO)。首先运用精英化思想将Logistic-Tent复合混沌映射与反向学习结合,优化灰狼种群分布序列;然后引入sigmoid函数修改收敛因子a,平衡算法全局探索与局部开发能力,并改进控制参数C以更好地拟合灰狼实际捕猎过程;最后加入随适应度值变化的比例权重,提高灰狼个体搜索能力,同时采用种群淘汰策略,淘汰适应度值差的个体,促进种群进化。选用3组不同的栅格地图进行实验,实验结果表明:由LTGWO算法生成的平均路径长度、路径长度标准差都优于对比算法。

基于深度学习无人机影像道路实景三维修复

针对基于无人机倾斜影像实景三维重建中,移动目标对道路实景三维重建造成几何变形和纹理失真的问题,提出一种基于深度学习的无人机影像道路实景三维修复方法。首先,通过添加注意力机制的深度学习网络模型YOLOv8对影像中目标进行检测;其次,在得到影像对应目标标记的基础上,根据已生成三维Mesh模型中各三角面在可视影像集合中的投影位置,结合影像所标记目标的对应范围,统计各三角面的类别信息以此判定移动目标;最后,利用移动目标判定结果对移动目标造成的三维模型几何变形及纹理错误进行修复,实现道路实景三维重建。结果表明:改进的网络模型较YOLOv4、YOLOv5和YOLOv8模型,平均精度(mAP)值平均提升10.82%,移动目标判定准确率达97.43%。与流行国外商业软件相比,所提方法重建修复效果更佳,自动化程度更高。

面向昏暗动态场景下的VSLAM算法

视觉同步定位与建图(VSLAM)在地下探索机器人和搜救机器人等领域中具有广泛的应用。然而,机器人在完成相关任务时,常常需要处在昏暗动态场景中,此时传统VSLAM算法精度较低,而现有的面向昏暗动态场景的VSLAM算法则往往难以满足实时性的要求。为解决这一问题,该文提出了一种面向昏暗动态场景的实时VSLAM算法。该算法基于ORB-SLAM3架构,首先利用基于Retinex理论的图像增强技术对输入图像进行预处理,从而提升算法在低光照条件下的稳定性;然后,结合YOLOv5物体检测技术,通过高斯分布分析和LK光流技术,对YOLO检测框内的动态特征点进行精准过滤,保留框内的静态特征点。在TUM、Bonn以及实测数据集上进行了验证。实验结果表明,相比ORB-SLAM3,该算法在高动态环境中的绝对轨迹误差(ATE)提升了至少86.93%,在低动态环境中也提升了27.61%。与同类型的VSLAM算法相比,该文所提算法在保持较高定位精度的同时,处理速度更快,实现了精确性和实时性的良好平衡。

具有不同干预措施的家禽-野鸟禽流感模型分析

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