A multi-method approach to delineate and validate migratory corridors

Context

Managers are faced with numerous methods for delineating wildlife movement corridors, and often must make decisions with limited data. Delineated corridors should be robust to different data and models.

Objectives

We present a multi-method approach for delineating and validating wildlife corridors using multiple data sources, which can be used conserve landscape connectivity. We used this approach to delineate and validate migration corridors for wildebeest (Connochaetes taurinus) in the Tarangire Ecosystem of northern Tanzania.

Methods

We used two types of locational data (distance sampling detections and GPS collar locations), and three modeling methods (negative binomial regression, logistic regression, and Maxent), to generate resource selection functions (RSFs) and define resistance surfaces. We compared two corridor detection algorithms (cost-distance and circuit theory), to delineate corridors. We validated corridors by comparing random and wildebeest locations that fell within corridors, and cross-validated by data type.

Results

Both data types produced similar RSFs. Wildebeest consistently selected migration habitat in flatter terrain farther from human settlements. Validation indicated three of the combinations of data type, modeling, and corridor detection algorithms (detection data with Maxent modeling, GPS collar data with logistic regression modeling, and GPS collar data with Maxent modeling, all using cost-distance) far outperformed the other seven. We merged the predictive corridors from these three data-method combinations to reveal habitat with highest probability of use.

Conclusions

The use of multiple methods ensures that planning is able to prioritize conservation of migration corridors based on all available information.

     

Rhabdovirus-like particles in the sporocyst of the trematode Brachylaimus fuscatus from terrestrial mollusc Ponsadenia duplocincta

Rhabdovirus-like particles containing nucleoprotein in a helix with eight turns was demonstrated by transmission electron microscopy in subtegumental cells and syncytial layer of tegument in Brachylaimus fuscatus sporocyst. This is the first case of virus infection in trematodes. The possibility of transfer of the virus to intra-molluscan parasitic generations of the trematode is discussed with respect to the peculiarities of the life cycles of the family Brachylaimidae.     

Database derived microsatellite markers (SSRs) for cultivar differentiation in <Emphasis Type="Italic">Brassica oleracea</Emphasis>

Fifty-nine Brassica oleracea cultivars, belonging to five botanical varieties, were evaluated for microsatellite (SSR) polymorphisms using 11 database sequence derived primer pairs. The cultivars represented 12 broccoli (Brassica oleracea var. italica), ten Brussels sprouts (B. o. var. gemmifera), 21 cabbage (B. o. var. capitata, including the groups white and red cabbage), six savoy cabbage (B. o. var. sabauda), and ten cauliflower (B. o. var. botrytis) cultivars from 13 seed suppliers. The 11 primer pairs amplified in total 47 fragments, and differentiated 51 of the cultivars, whereas the remaining eight cultivars were differentiated from the rest in four inseparable pairs. All SSR markers, except one, produced a polymorphic information content (PIC value) of 0.5 or above. The average diversity for all markers within the tested material was 0.64. There was no major difference in the diversity within botanical varieties and groups. The cluster analysis and the resulting dendrogram showed that the cultivars tended to group within these taxonomic units. The present study substantiates the use of microsatellite markers as a powerful tool for cultivar differentiation and identification in vegetable brassicas.     

“WaterMan”: an on-farm water management game with heuristic capabilities

A modern computer-based simulation tool (WaterMan) in the form of a game for on-farm water management was developed for application in training events for farmers, students, and irrigators. The WaterMan game utilizes an interactive framework, thereby allowing the user to develop scenarios and test alternatives in a convenient, risk-free environment. It includes a comprehensive soil water and salt balance calculation algorithm. It also employs heuristic capabilities for modeling all of the important aspects of on-farm water management, and to provide quantitative performance evaluations and practical water management advice to the trainees. Random events (both favorable and unfavorable) and different strategic decisions are included in the game for more realism and to provide an appropriate level of challenge according to player performance. Thus, the ability to anticipate the player skill level, and to reply with random events appropriate to the anticipated level, is provided by the heuristic capabilities used in the software. These heuristic features were developed based on a combination of two artificial intelligence approaches: (1) a pattern recognition approach and (2) reinforcement learning based on a Markov decision processes approach, specifically the Q-learning method. These two approaches were combined in a new way to account for the difference in the effect of actions taken by the player and action taken by the system in the game world. The reward function for the Q-learning method was modified to reflect the suggested classification of the WaterMan game as what is referred to as a partially competitive and partially cooperative game.     

固化土结构沼气池试验研究初报

固化土结构沼气池是在传统以砖砌体沼气池和混凝土现浇沼气池建造基础上，利用土壤固化技术建造的一种新型户用水压式沼气池。将固化土作为池底结构材料和池壁材料，在冲积土、紫色土、黏土等3种土壤条件下建造了不同组合模式的固化土结构沼气池。经破坏性极限压力试验表明，所建沼气池均符合国家《户用沼气池质量检验验收规范GB/T4751-2002》标准。对固化土结构沼气池与传统沼气池建造成本进行详细分析，结果表明，由于部分建池材料实现就地取材，商品建材的使用量和运输量减少，建池成本降低，具有显著的经济效益和广阔的推广前景。     

基于投影寻踪原理的云南旱灾评估

为了能够对复杂的干旱灾害系统进行灾后评估,反映云南旱灾灾后综合损失,为云南防旱抗旱减灾策略提供理论依据。以云南1950-2009年的旱灾受灾、成灾面积,粮食损失为评价指标,采用投影寻踪法得到分级评估后的综合评价指标。计算结果表明：云南是一个干旱灾害频发且严重的省份,平均2.3年就会出现一次比较严重的旱灾,60年来重大灾害以上发生频次和旱灾损失程度不断上升,给云南经济社会带来了巨大影响,特别是2000年以来的10年期间,发生重大灾害以上次数高达9次,其中重大灾害1次,特大灾害8次。     

Gas analysis of the lunar surface

The rare gas analysis of the lunar surface has lead to important conclusions concerning the moon. The large amounts of rare gases found in the lunar soil and breccia indicate that the solar atmosphere is trapped in the lunar soil as no other source of such large amounts of gas is known. The cosmogenic products indicate that the exposure ages of the 17 lunar rocks measured vary from 20 to 400 million years with some grouping of the ages. The most striking feature is the old potassium-argon age which for the 14 rocks analyzed varies from 2.5 to 3.8 billion years. It is concluded that Mare Tranquillitatis crystallized about 4 billion years ago from a molten state produced by a large meteorite impact or volcanic flow.     

建立中国农产品质量安全市场准入机制框架分析

笔者利用政府经济学的一般原理,通过规范性分析,提出了政府建立农产品质量安全市场准入机制的目标和原则,明确了农产品质量安全市场准入规制的主体、客体及范围,提出了农产品市场准入机制的构架建议,为中国政府建立农产品市场准入机制提供了理论参考。     

Physical Properties of Urban Soils in Rostov Agglomeration

Transformation of particle-size composition, structure, and density of soils upon urbopedogenesis is considered for Rostov agglomeration. Various soils are compared by horizons. It is found that the share of sand fractions increases in upper and middle horizons of migration–segregation chernozems (Calcic Chernozem (Hyperhumic, Loamic)), above all, at the expense of particles of 0.05—0.001 mm in size; with the coarse medium sand fraction 1–0.25 mm being diagnostic for urbopedogenesis. The reason is the introduction of sandy particles upon urban construction, arranging water conduits and other utility lines, as well as the use of icing-control sandy mixtures. The Dolgov-Bakhtin schedule appears to be the most appropriate for assessing the structure of urban soils. Dry sieving testified to the decreasing amount of agriculturally valuable aggregates in all compared pairs of horizons in the sequence of urban soils: under forest vegetation → under steppe vegetation → in the buried massif of urbosoils. The water stability of aggregates decreases in the sequence: soils under steppe vegetation → buried horizons of urbosoils → soils under forest vegetation. The following sequence of urbic horizons (UR and RAT) shows a decrease in the share of agriculturally valuable fractions and an increase in their water stability: heavy-textured UR → light-textured UR → RAT. The density of natural soils varies insignificantly within the city territory, with its urbostratified soils (Calcic Chernozem Novic (Technic Loamic) in residential areas often manifesting the maximal density.     

不同脱粒与干燥方式对稻米品质的影响

选用代表型品种 (组合 )南京 16 (代表中稻 )、金优 2 0 7(代表晚稻籼型 )、鄂宜 10 5(代表晚稻粳型 )进行不同的脱粒与干燥处理 ,以考察不同处理对稻米品质的影响。脱粒方式处理分为人工链杆击打、拖拉机带动石磙碾落和联合收割机脱粒 ;干燥方式处理分为在水泥地上自然晒干、放在竹垫上自然晒干和机械通风干燥。两种处理共交叉组合成 9种交叉处理。结果表明 ,不同脱粒与干燥处理对米质中的整精米率和垩白度指标影响最大。其中 ,脱粒方式对稻米整精米率的影响较大 ,同时对南京 16垩白度的影响较大 ;干燥方式对金优 2 0 7和晚粳鄂宜 10 5垩白度的影响较大 ;两种处理方式之间互作效应显著 ,最佳组合处理为联合收割机脱粒加机械通风干燥处理。不同处理方式对中稻品种南京 16米质的影响要大于对晚粳鄂宜 10 5和晚杂组合金优2 0 7。