Microstructures of Antarctic cidaroid spines: diversity of shapes and ectosymbiont attachments

The echinoderm endoskeleton, located in the connective layer of the tegument, is organized into a three-dimensional mesh, the stereom. Among echinoids, the cidaroids depart from this pattern, and the shaft of the spine lacks an epidermis. Thus, the spines lack antifouling protection, allowing ectosymbionts such as bryozoans and foraminiferans to attach. This raises a question about the adaptive role of the cortical layer of the stereom. This study examined the micro- and mesostructure of the spines of 11 cidaroid species collected in the Weddell Sea and Drake Passage, and the nature of their ectosymbiont attachments. Scanning electron microscopy was used to characterize the cortex surface and X-ray micro computed tomography (μCT) to describe the symbiont attachments. Spine microstructure features provide a useful taxonomic character for distinguishing among three species in the genus Ctenocidaris, and challenge a previous parasitic interpretation of cortical filaments on the spines of Rhynchocidaris triplopora. Ectosymbiont attachments were classified as Anchoring, Molding, Cementing, or Corroding. The study suggests that some microstructure features may be protective, keeping the ectosymbionts away from the cortex and loosely attached at intervals along the shaft of the spine, while other micro-structures facilitate attachment over considerable areas of the shaft. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Age-related changes in an insect mating signal have no effect on female choice

The structure of male mating signals is often influenced by age. The causes and consequences of age-based signal variation have been much studied in visual, acoustic, and chemical signaling modalities, but are less explored in species that use vibrational signals for mate attraction. However, the complex structure of many vibrational signals makes them ideal for investigating the relationships between age, signal variation, and patterns of female choice. In the thornbug treehopper, Umbonia crassicornis, females mate more often with older males, but the mechanism underlying older male mating success is unknown. Our goals in this study were to determine whether male vibrational mate advertisement signals vary with age, and, if so, whether females prefer the signals of older males. We recorded male signals over four consecutive weeks beginning at the onset of signaling (a period spanning most of the male reproductive lifespan), and measured ten temporal, spectral, and energy-related parameters from each signal. Several features of male signals changed markedly with age. However, females responded similarly to signals representing males of different ages, indicating that they do not favor older males on the basis of long distance mate advertisement signals. Nonetheless, the results reveal that even in short-lived, determinate growth species age can have surprisingly large effects on mating signals, and we discuss some factors that may contribute to age-related signal variability in U. crassicornis.     

Agricultural production and sustainable development in a Brazilian region (Southwest,São Paulo State): motivations and barriers to adopting sustainable and ecologically friendly practices

The objective of this study is to identify the adoption level of practices associated with more sustainable agriculture and environmentally friendly practices. Additionally, the motivations for and barriers to the adoption of these practices by farmers are investigated. Data were collected through closed questionnaires taken by a random sample of farmers in the Southwest, São Paulo, Brazil, during the second half of 2013. Overall, sustainable agricultural practices recommended in the literature and analysed in this study are being not fully adopted by farmers of the studied area. The results showed that financial motivation is associated with farmers adopting new, more sustainable technology, whereas the lack of information on and lack of technical support for these technologies are significant barriers. Other results, research implications, limitations and suggestions for future research are presented.     

Measuring sedimentation in tidal marshes: a review on methods and their applicability in biogeomorphological studies

It is increasingly recognised that interactions between geomorphological and biotic processes control the functioning of many ecosystem types as described e.g. by the ecological theory of ecosystem engineering. Consequently, the need for specific bio-geomorphological research methods is growing recently. Much research on bio-geomorphological processes is done in coastal marshes. These areas provide clear examples of ecosystem engineering as well as other bio-geomorphological processes: Marsh vegetation slows down tidal currents and hence stimulates the process of sedimentation, while vice versa, the sedimentation controls ecological processes like vegetation succession. This review is meant to give insights in the various available methods to measure sedimentation, with special attention to their suitability to quantify bio-geomorphological interactions. The choice of method used to measure sedimentation is important to obtain the correct parameters to understand the biogeomorphology of tidal salt marshes. This review, therefore, aims to be a tool for decision making regarding the processes to be measured and the methods to be used. We, subdivide the methods into those measuring suspended sediment concentration (A), sediment deposition (B), accretion (C) and surface-elevation change (D). With this review, we would like to further encourage interdisciplinary studies in the fields of ecology and geomorphology.     

A note on a non-stationary point source spatial model

A point source, non-stationary covariance structure model is proposed, having only one additional parameter over a standard, stationary covariance structure, spatial model. Additionally, the proposed model is demonstrated to fit better than the three extra parameter, point source, non-stationary spatial model proposed by Ecker and De Oliveira (Commun Stat Theory Methods 37:2066–2078, 2008). The proposed model is fit from a Bayesian perspective and illustrated using a house sales dataset from Cedar Falls, Iowa.     

Maturation of work attitudes: Correlated change with big five personality traits and reciprocal effects over 15 years

As employees grow older, do their attitudes regarding work change over time? Can such long‐term changes be understood from a personality development perspective? The present study addressed these fundamental questions by tracking 504 young professionals' work attitudes (i.e., job satisfaction and work involvement) and Big Five personality traits over the first 15 years of their professional career. We specifically investigated whether trait changes drive peoples' changing attitudes, a mechanism we called maturation of work attitudes. Latent change models first indicated significant associations between traits and attitudes at the beginning of the career, and mean‐level changes in Big Five traits (i.e., increases in Agreeableness and Conscientiousness and decreases in Neuroticism) in the direction of greater functional maturity. Although no significant mean‐level changes in work attitudes were observed, results regarding correlated change indicated that variability in attitude change was related to variability in trait change and that this indeed signaled a maturational process. Finally, reciprocal effect estimates highlighted bidirectional relations between personality and attitudes over time. It is discussed how these results (i) provide a better understanding of potential age effects on work‐related attitudes and (ii) imply a revision of the traditional dispositional approach to attitudes. Copyright © 2013 John Wiley & Sons, Ltd.     

Congenital predispositions and early social experience determine the courtship patterns of males of the Amarillo fish

Mounting evidence indicates that learning shapes fish foraging and social behavior, which suggests that it may also underlie the frequently reported geographic variation in courtship. In this study, we analyzed how early social experience influences courtship patterns in males of the Amarillo fish (Girardinichthys multiradiatus). In a first experiment, we quantified the courtship of males from two allopatric populations grown in isolation and estimated the heritability of a key attribute of their courtship patterns. Then, we raised males from two allopatric populations with either sympatric or allopatric females and at two different densities, and registered their adult courtship patterns towards females from a third population. We found that the courtship pattern of males has a significant heritable component, yet in the second experiment, it was influenced by what type of females males were raised with, by their social rank (dominant/subordinate/singleton), and by the behavior of the female that they were courting. We conclude that courtship behavior in this fish has a congenital predisposition and is affected during development by different aspects of early experience and seemingly remains flexible throughout life; a complex ontogenetic trajectory that under natural conditions may have led to the locally stable dialect types observed in the courtship patterns of males from allopatric populations.     

洞庭湖区地表温度反演及其时空变化特征

洞庭湖是我国第二大的淡水湖,对区域气候的调节起着极其关键的作用,然而受全球变暖及其他因素的影响,洞庭湖区范围内对气候变化的响应并不一致。为了更好地认识洞庭湖区的地表温度变化及其对全球变暖的响应情况,同时为准确的判断该区温度未来的变化趋势奠定基础,利用1995年、2004年和2013年12景冬季Landsat TM/ETM＋遥感影像的热红外波段数据反演了洞庭湖区地表温度,并对反演的地表温度值进行标准化处理,采用标准差分类法得到地表温度等级图。通过三时相温度等级图的面积统计与直观对比,分析了洞庭湖区在三峡蓄水前后的温度时空变化特征;并结合归一化植被指数（NDVI）、降雨资料、DEM、坡度等数据对洞庭湖区的温度变化影响因素进行了统计分析。结果表明,（1）洞庭湖区各温度等级面积成正态分布,主要以中温区、较高温区和较低温区为主。从空间分布上来看,低温区主要分布在水体,而高温区则没有明显的分布特征。（2）受雨雪天气影响,2004年的高温范围减少,减少情况为西洞庭湖区〉南洞庭湖区〉东洞庭湖区,面积变化比例分别是5.38%、2.12%、0.71%,表明冷气流对西洞庭湖区的温度变化影响最强,而东洞庭湖区最弱。（3）2013年高温范围增加,且变化强度呈现出西洞庭湖区〈南洞庭湖区〈东洞庭湖区的空间特征,面积变化比例分别是2.21%、2.38%、2.68%,表明在三峡水库蓄水之后,东洞庭湖区的地表温度受到较大影响。（4）植被的覆盖情况与温度相关性不明显,而坡度、海拔与温度呈正相关关系,这表明坡度可以有效的减少冷气流对温度的影响,地势较高地区与阳坡出现高温情况则表明地表温度受太阳辐射影响较大。     

辛置煤矿310轨道巷围岩破裂范围研究

辛置煤矿310轨道巷属于高应力软岩巷道,地质构造和岩层结构非常复杂多变。为了解该巷道的松动范围、塑性区分布和围岩破坏情况,采用U510非金属超声波检测仪,在辛置煤矿310轨道巷左右两帮合理布置检测点,进行现场松动圈测试。获得一系列测试结果,运用测试结果及围岩松动圈支护理论,可对310轨道巷支护提供理论依据。     

锅炉燃煤的最佳方式

从节能、环保、资源开发并重并举的高度,探讨了锅炉燃煤的最佳方式和技术经济的可行性,认为先热解后燃烧,特别是以廉价氢源进行加氢热解后再燃烧是锅炉燃煤的最佳方式。