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161.
Grassland birds are among the most globally threatened bird groups due to substantial degradation of native grassland habitats. However, the current network of grassland conservation areas may not be adequate for halting population declines and biodiversity loss. Here, we evaluate a network of grassland conservation areas within Wisconsin, U.S.A., that includes both large Focal Landscapes and smaller targeted conservation areas (e.g., Grassland Bird Conservation Areas, GBCAs) established within them. To date, this conservation network has lacked baseline information to assess whether the current placement of these conservation areas aligns with population hot spots of grassland‐dependent taxa. To do so, we fitted data from thousands of avian point‐count surveys collected by citizen scientists as part of Wisconsin''s Breeding Bird Atlas II with multinomial N‐mixture models to estimate habitat–abundance relationships, develop spatially explicit predictions of abundance, and establish ecological baselines within priority conservation areas for a suite of obligate grassland songbirds. Next, we developed spatial randomization tests to evaluate the placement of this conservation network relative to randomly placed conservation networks. Overall, less than 20% of species statewide populations were found within the current grassland conservation network. Spatial tests demonstrated a high representation of this bird assemblage within the entire conservation network, but with a bias toward birds associated with moderately tallgrasses relative to those associated with shortgrasses or tallgrasses. We also found that GBCAs had higher representation at Focal Landscape rather than statewide scales. Here, we demonstrated how combining citizen science data with hierarchical modeling is a powerful tool for estimating ecological baselines and conducting large‐scale evaluations of an existing conservation network for multiple grassland birds. Our flexible spatial randomization approach offers the potential to be applied to other protected area networks and serves as a complementary tool for conservation planning efforts globally.  相似文献   
162.
Many publications make use of opportunistic data, such as citizen science observation data, to infer large‐scale properties of species’ distributions. However, the few publications that use opportunistic citizen science data to study animal ecology at a habitat level do so without accounting for spatial biases in opportunistic records or using methods that are difficult to generalize. In this study, we explore the biases that exist in opportunistic observations and suggest an approach to correct for them. We first examined the extent of the biases in opportunistic citizen science observations of three wild ungulate species in Norway by comparing them to data from GPS telemetry. We then quantified the extent of the biases by specifying a model of the biases. From the bias model, we sampled available locations within the species’ home range. Along with opportunistic observations, we used the corrected availability locations to estimate a resource selection function (RSF). We tested this method with simulations and empirical datasets for the three species. We compared the results of our correction method to RSFs obtained using opportunistic observations without correction and to RSFs using GPS‐telemetry data. Finally, we compared habitat suitability maps obtained using each of these models. Opportunistic observations are more affected by human access and visibility than locations derived from GPS telemetry. This has consequences for drawing inferences about species’ ecology. Models naïvely using opportunistic observations in habitat‐use studies can result in spurious inferences. However, sampling availability locations based on the spatial biases in opportunistic data improves the estimation of the species’ RSFs and predicted habitat suitability maps in some cases. This study highlights the challenges and opportunities of using opportunistic observations in habitat‐use studies. While our method is not foolproof it is a first step toward unlocking the potential of opportunistic citizen science data for habitat‐use studies.  相似文献   
163.
食用菌因其富含多种氨基酸及微量元素等物质,具有较高的营养价值和药用价值,越来越受到人们的关注和喜爱。我国作为最重要的食用菌生产国,食用菌生产规模不断扩大,产量也在逐年提高。为了更好地发展食用菌产业,迫切需要在传统的食用菌产业链,如优良品种选育及栽培生产中融入新技术。生物信息学作为一门研究分析生物生命结构的技术门类,通过运用数学、计算机科学等工具揭示了数据所蕴含的生物学意义,极大地促进了生命科学研究的发展,也为食用菌更深入的研究与应用提供了技术保障。本文从食用菌育种及种质资源调查、病虫害防治、基因组学、食用菌安全等几方面阐述了生物信息学在食用菌领域的具体应用,对生物信息学在食用菌及农业领域的发展进行了展望,以期为促进食用菌研究和生产发展提供参考。  相似文献   
164.
165.
The determination of the post-mortem interval (PMI) of skeletal remains is a challenging aspect in the forensic field. Previous studies focused their attention on different macroscopic and morphological aspects but a thorough and complete evaluation of the potential of chemical and physical analyses in this field of research has not been performed. In addition to luminol test and Oxford histology index (OHI) reported in a recent paper, widely spread and accessible methods based on physical aspect and chemical characteristics of skeletal remains have been investigated as potential alternatives to dating by determination of 14C.The investigation was performed on a total of 24 archeological and forensic bone samples with known PMI, with inductively coupled plasma optical emission spectrometer (ICP-OES), inductively coupled plasma quadruple mass spectrometry (ICP-MS), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray analysis (EDX), powder X-ray diffraction analysis (XRPD) and scanning electron microscopy (SEM). Finally, the feasibility of such alternative methods was discussed. Some results such as carbonates/phosphates ratio from FT-IR, the amounts of organic and inorganic matter by EDX, crystallite sizes with XRPD, and surface morphology obtained by SEM, showed significant trends along with PMI. Though, from a chemical point of view cut-off values and gold-standard methods still present challenges, and rather different techniques together can provide useful information toward the assessment of the PMI of skeletal remains. It is however clear that in a hypothetical flowchart those methods may be placed practically at the same level and a choice should always consider the evaluation of results by each technique, execution times and a costs/benefits relationship.  相似文献   
166.
This article presents an analogy to illustrate the effect of surface roughness on surface wettability. I used a water-filled balloon to represent water droplet, a toothpick to represent surface roughness and Styrofoam as the surface. The analogies presented in this article will help visualize how roughness affects the wettability of the surface and therefore can be used to introduce surface wettability to high school students.  相似文献   
167.
The research agenda of paleoanthropology involves many topics and methodologies. Fossil specimens are allocated to species, and those species are assigned to the hominin clade. After that we want to know how they are related to each other, what they ate, how much they weighed, how smart they were, etc. We also want to know about the origin of particular attributes of hominins, such as our delayed growth and development, bipedalism, and language. The data available to answer these complex questions are confounded by fragmentary fossil specimens, small sample sizes, limited opportunities for controlled experimentation, and the inherent limitations of historical data. Also, because many traits are effectively unique to hominins, even observational comparative studies are inevitably limited in what they can tell us, if not impossible to conduct. We explore how these limitations should, but often do not, constrain the questions that paleoanthropologists should attempt to answer.  相似文献   
168.
Using the Southern African Bird Atlas Project (SABAP2) as a case study, we examine the possible determinants of spatial bias in volunteer sampling effort and how well such biased data represent environmental gradients across the area covered by the atlas. For each province in South Africa, we used generalized linear mixed models to determine the combination of variables that explain spatial variation in sampling effort (number of visits per 5′ × 5′ grid cell, or “pentad”). The explanatory variables were distance to major road and exceptional birding locations or “sampling hubs,” percentage cover of protected, urban, and cultivated area, and the climate variables mean annual precipitation, winter temperatures, and summer temperatures. Further, we used the climate variables and plant biomes to define subsets of pentads representing environmental zones across South Africa, Lesotho, and Swaziland. For each environmental zone, we quantified sampling intensity, and we assessed sampling completeness with species accumulation curves fitted to the asymptotic Lomolino model. Sampling effort was highest close to sampling hubs, major roads, urban areas, and protected areas. Cultivated area and the climate variables were less important. Further, environmental zones were not evenly represented by current data and the zones varied in the amount of sampling required representing the species that are present. SABAP2 volunteers' preferences in birding locations cause spatial bias in the dataset that should be taken into account when analyzing these data. Large parts of South Africa remain underrepresented, which may restrict the kind of ecological questions that may be addressed. However, sampling bias may be improved by directing volunteers toward undersampled regions while taking into account volunteer preferences.  相似文献   
169.
The naturalist Alfred Russel Wallace (1823–1913) has for many years been standing in the shadow of his more famed co‐discoverer of the principle of natural selection, Charles Darwin. Despite outward similarities between the two men's formulation of the principle, Wallace had fit his appreciation of natural selection into views on evolution that were quite different from Darwin's. A closer examination of what Wallace had in mind suggests a model of process in which natural selection per se acts as the negative feedback mechanism (actually, a ‘state‐space’) in the relation between population and environment, and environmental engagement as made possible by the resulting selection of traits acts as the positive feedback part of the cycle. Thus, it may be better to contextualize adaptive structures as entropy‐relaying biogeochemical facilitators that only ‘generate a potential for evolution’ than to portray them as the end results of evolution. This systems point of view better lends itself to appreciations of the biogeographical context of evolution than does the tree‐thinking of a more conventional style of speciation‐focused Darwinism, which sometimes confuses process with result.  相似文献   
170.
Collaborating Authors: Bee Gunn, Wayne Law, George Yatskievych, Wu Sugong, Fang Zhendong, Ma Jian, Wang Yuhua, Andrew Willson, Peng Shengjing, Zhang Chuanling, Sun Hongyan, Meng Zhengui, Liu Lin, Senam Dorji, Ana, Liqing Wangcuo, Sila Cili, Adu, Naji, Amu, Sila Cimu, Sila Lamu, Lurong Pingding, Zhima Yongzong, Loangbao, Bianma Cimu, Gerong Cili, Wang Kai, Sila Pingchu, Axima, and Benjamin Staver.TIBETAN LAND USE AND CHANGE NEAR KHAWA KARPO, EASTERN HIMALAYAS. Economic Botany 59(4):312-325, 2005. Tibetan land use near Khawa Karpo, Northwest Yunnan, China, incorporates indigenous forest management, gathering, pastoralism, and agriculture. With field-based GIS, repeat photography, and Participatory Rural Appraisal we quantitatively compare land use between higher and lower villages, and between villages with and without roads. Households in higher elevation (> 3,000 meters) villages cultivate more farmland (z = -5.387, P ≤ 0.001), a greater diversity of major crops (z = -5.760, P < 0.001), a higher percentage of traditional crops, and fewer cash crops (z = -2.430, P = 0.015) than those in lower elevation villages (< 2,500 meters). Villages with roads grow significantly more cash crops (z = -6.794, P ≤ 0.001). Both lower villages and villages with roads travel farther to access common property resources. Historical analyses indicate agricultural intensification in valleys, an increase in houses, new crop introduction, hillside aforestation, cessation of hunting, glacial retreat, and timberline advance within the past century. We suggest that Tibetan land use reveals trade-offs between high, remote villages and lower villages near roads. Higher villages offer abundant land and access to natural resources but short growing seasons and little market access; in contrast, lower villages have road and market access, an extended growing season, and modern technology, but limited access to land and many other natural resources.  相似文献   
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