Reliability of digit length impression as a character of tetrapod ichnotaxobase: considerations from the Carboniferous–Permian ichnogenus Ichniotherium

Although the relative length of digit impressions is often adopted as a binding character in ichnotaxa discrimination and trackmaker identification, it cannot be considered unequivocally operative. The reliability of this character has been evaluated by means of principal component analysis on several well‐preserved footprints (both manus and pes) referred to as Ichniotherium sphaerodactylum from the Early Permian Tambach Formation (Thuringia, Germany). The analysis reveals a substantial variability of digit impression length (especially in the manus), relativizing the validity of digit IV length as a diagnostic character as practised in different ichnological studies. Regarding the use of such a character, results clearly suggest the need to preliminarily conduct explorative analysis on the whole available ichnological material in order to detect which digit is the most consistent from an ichnotaxonomical standpoint, thus avoiding an arbitrary selection. Such a preliminary analysis should provide a better control on ichnotaxonomical splitting/lumping, particularly in the case of allied footprints, and can also be considered a valuable tool, if associated to functionality analysis, in improving and refining trackmaker identification. Copyright © 2014 John Wiley & Sons, Ltd.     

基于模糊数学评价法优化凡纳滨对虾真空微波干燥工艺

【目的】探求真空微波干燥凡纳滨对虾的最佳工艺条件,以期为开发凡纳滨对虾即食食品提供技术参考。【方法】以新鲜凡纳滨对虾为原料,模糊数学感官评分为主要考察指标,在单因素试验基础上,选择载装量A、功率B、真空度C为自变量,利用响应面法和模糊数学评价法对真空微波干燥工艺进行优化。【结果】以感官评定为基础对真空微波干燥凡纳滨对虾的品质进行权重分析,得到权重集K=(色泽0.335,滋味0.305,香气0.215,组织质地0.145)。建立二次多项回归方程:Y=84.588+1.084A+1.409B+1.700C-7.353A²-8.793B²-13.860C²,显示载装量A、功率B、真空度C对感官评分有极显著影响(P<0.01)。通过响应面分析,得到真空微波干燥凡纳滨对虾的最佳工艺条件:载装量75 g,加热功率400 W,真空度0.08 MPa。在此条件下,真空微波干燥凡纳滨对虾品质良好,感官评分为(85.6±0.07)分,与预测值85.92分误差较小。【结论】响应面法优化凡纳滨对虾真空微波干燥工艺具有操作简单、优化条件精确、结果显示直观等优点;建立的回归方程能反映装载量等三个因素对指标的影响规律,并可进行实际预测。     

Exploring the relationships between perceived neighborhood boundaries and street network orientation

The neighborhood is a core unit of analysis in urban research, planning, and policy-making. However, perceptual and historical processes oftentimes result in neighborhoods that are not tied to sub-urban jurisdictions. For instance, historic neighborhoods might lack official spatial definitions, hampering neighborhood-based tasks in local offices. In this case, urban practitioners can benefit from readily available spatial proxies, such as the local street network. In this study, we conducted an exploratory analysis that combines neighborhood mapping and street network modeling. By retrieving participants' sketched boundaries and quantifying spatial orientations of sketched polygons and local network patterns, we were able to measure and compare the relationships between the urban fabric and the perceived extents of two historic neighborhoods in Lisbon, Portugal. The results provided insights for enhancing existing definitions of non-official neighborhoods, outlining new urban districts as well as for discussions about the role of the urban form in shaping people's perceptions.     

Using maps of continuous variation in species compositional turnover to supplement uniform polygon species range maps

Species ranges are often represented using polygons, with the attendant issues that they show uniform ranges with abrupt boundaries and can overestimate species ranges. We demonstrate that such uniform species ranges can be supplemented by mapping the gradational variation in species turnover across a landscape. Directional variation in species turnover for 15 skink species (Reptilia: Scincidae) and topographic and climatic turnover in south-eastern Australia were measured using directional moving window analyses, rotated through 360°. The resultant species turnover maps were compared with published polygon range maps for two species within the group (Liopholis whitii and L. inornata). We also assessed how the relationships between species and environmental turnover varied in areas of low or high species turnover. Continuous transitions between distinct areas of low and high species turnover were mapped. Low turnover comprised only 19% of the L. whitii polygon species range within the study area extent. These low turnover areas were more densely populated by L. whitii (67% of observations), whereas areas of medium to high turnover contained substantially fewer observations (25%). Regions with the highest species turnover contained only 6% of observations. L. inornata observations were also clustered in low species turnover areas. Averaged climatic and elevation values were higher in low-turnover areas despite their close adjacency to high-turnover zones. The environmental turnover in low species turnover regions was also lower than in high-turnover areas. Correlations between environmental turnover and low species turnover areas were positive, whereas the opposite relationship applied in high species turnover areas. We identified both abrupt and gradual distributional breaks between separate reptile assemblages; an example of the latter is located in the Hunter Valley in the south-eastern coastal region. This break has been mapped using solid, uniform lines in species ranges and thus implicitly as an abrupt break. Environmental conditions may be more favourable to skinks in low-turnover areas. Since L. whitii and other skink species have very large populations in low-turnover areas, other squamate species may also be more likely to occur in these areas. This has potential implications for conservation prioritisation. The turnover maps used here can supplement the information provided about reptile distributions by the equivalent polygon ranges. This approach can be applied to point occurrence data for any taxonomic group or any similar georeferenced diversity data set.     

基于二分搜索的水深数据与遥感影像匹配算法

研究了遥感水深反演的数据匹配方法,分析了插值加密法与最短距离法的优缺点。针对高分辨率卫星影像海量数据,传统匹配方法无法有效进行数据匹配问题,提出基于二分搜索的阈值距离法。实验表明,新算法的匹配效率与匹配精度得到了显著提高,有助于获得更好的水深反演效果。     

雨量计与星载测雨雷达资料结合的降水估算方法

利用华东地区97个气象站点,1998—2012年逐月降水资料和TRMM卫星降水产品,基于卫星结合雨量计降水估算方法,并考虑海拔高度对降水的影响,对华东地区的降水进行估算,得到研究区域降水的时空分布情况。通过误差验证,发现估算值与站点实测值之间具有较好的一致性,并且1、4、10月的估算值要好于7月的估算值。总体而言,该方法能够对华东地区进行较好的降水估算,并且能够反映研究区域的降水空间分布情况。     

Stability of the sponge assemblage of Mediterranean coralligenous concretions along a millennial time span

The Mediterranean coralligenous substratum is a hard bottom of biogenic origin, mainly composed of calcareous algae, growing in dim light conditions. Sponges are among of the most representative taxa of the coralligenous assemblages, with more than 300 recorded species of different habits: massive, erect, boring and insinuating. When sponges die, their siliceous spicules remain trapped in the biogenic concretion, offering the opportunity to describe the coralligenous spongofauna over a very long span of time, virtually dating back to a large part of the Holocene period. The data reported here were obtained from core samples collected from four coralligenous concretions. Each block was collected in a different locality of the Ligurian Sea: Santo Stefano Shoals, Bogliasco, Punta del Faro (Portofino Promontory) and Punta Manara. Radiocarbon age determinations indicate for these conglomerates a maximal age between 1600 and 3100 years. The spicules trapped in the cores show deep dissolution marks in the form of circular holes on their surface or present an enlargement of the axial canal. However, their original shape, generally intact, suggests the absence of mechanical injuries and allows a tentative identification at the species level. The analysis of these old spicules reveals an ancient sponge assemblage composed of 30 recognisable species. This indicates that almost one half of the sponge community today settled on coralligenous substrata has been present in the conglomerates for their entire existence.     

Climate change impacts on wildfires in a Mediterranean environment

We analyse the observed climate-driven changes in summer wildfires and their future evolution in a typical Mediterranean environment (NE Spain). By analysing observed climate and fire data from 1970 to 2007, we estimate the response of fire number (NF) and burned area (BA) to climate trends, disentangling the drivers responsible for long-term and interannual changes by means of a parsimonious Multi Linear Regression model (MLR). In the last forty years, the observed NF trend was negative. Here we show that, if improvements in fire management were not taken into account, the warming climate forcing alone would have led to a positive trend in NF. On the other hand, for BA, higher fuel flammability is counterbalanced by the indirect climate effects on fuel structure (i.e. less favourable conditions for fine-fuel availability and fuel connectivity), leading to a slightly negative trend. Driving the fire model with A1B climate change scenarios based on a set of Regional Climate Models from the ENSEMBLES project indicates that increasing temperatures promote a positive trend in NF if no further improvements in fire management are introduced.     

Similarities and differences of two evapotranspiration models with routinely measured meteorological variables: application to a cropland and grassland in northeast China

Local actual evapotranspiration can be estimated with routinely measured meteorological variables using the Penman–Monteith model with surface resistance parameterized via the Katerji and Perrier approach (Agronomie 3(6):513–521, 1983; PM–KP model), or the nonlinear complementary relationship (CR) model proposed by Han et al. (Hydrol Process 26:3973–3981, 2012). A comparative study was carried out to evaluate the consistencies and differences of two models, as well as the performances of them for a cropland and grassland in northeast China. The departure of the actual evapotranspiration from the potential evaporation is described as a function of the ratio of the surface resistance to the aerodynamic resistance in the Penman–Monteith model, but the ratio of the aerodynamic term to the radiation term in the CR models. The two ratios are connected using a semi-empirical linear function by the Katerji and Perrier approach. The nonlinear CR model can be regarded as replacing the linear function by a power function after mathematical processing. On the other hand, the PM–KP model can be also considered as a CR-type model. On the daily basis at a maize cropland and degraded grassland in semiarid Northeast China, the nonlinear CR model with locally calibrated parameters performed better with data occupying all the growth stages, but the performances of the two models are similar during the early-, mid-, and late-season stages, respectively. On the half-hourly basis, the PM–KP model and the nonlinear CR model both performed well. It is deduced that on the daily basis the nonlinear CR model is more suitable for the cropland and grassland, but further comparisons are needed on the hourly basis.