Predicting insect phenology across space and time

Many species appear to be undergoing shifts in phenology, arising from climate change. To predict the direction and magnitude of future changes requires an understanding of how phenology depends on climatic variation. Species show large‐scale spatial variation in phenology (affected by differentiation among populations) as well as variation in phenology from year‐to‐year at the same site (affected predominantly by local plasticity). Teasing apart spatial and temporal variation in phenology should allow improved predictions of phenology under climate change. This study is the first to quantify large‐scale spatial and temporal variation in the entire emergence pattern of species, and to test the relationships found by predicting future data. We use data from up to 33 years of permanent transect records of butterflies in the United Kingdom to fit and test models for 15 butterfly species. We use generalized additive models to model spatial and temporal variation in the distribution of adult butterflies over the season, allowing us to capture changes in the timing of emergence peaks, relative sizes of peaks and/or number of peaks in a single analysis. We develop these models using data for 1973–2000, and then use them to predict phenologies from 2001 to 2006. For six of our study species, a model with only spatial variation in phenology is the best predictor of the future, implying that these species have limited plasticity. For the remaining nine species, the best predictions come from a model with both spatial and temporal variation in phenology; for four of these, growing degree‐days have similar effects over space and time, implying high levels of plasticity. The results show that statistical phenology models can be used to predict phenology shifts in a second time period, suggesting that it should be feasible to project phenologies under climate change scenarios, at least over modest time scales.     

Johansson revisited: the spatial structure of epiphyte assemblages

Question: Vertical zonation schemes are widely used in biodiversity studies with vascular epiphytes as a tool to capture spatial distribution patterns, the one most commonly used was proposed by Johansson more than 30 years ago. Does a survey of the epiphytes found on larger trees really yield a representative sample of the local community? Location: Lowland rainforest of the San Lorenzo Crane Plot, Republic of Panama. Methods: A complete census of the vascular epiphytes on all trees > 1 cm DBH in 0.4 ha of undisturbed lowland forest was analysed with both cluster and discriminant analysis to detect groupings of epiphyte species. Results: Six different groups of species were detected, five of them preferring different substrates on larger trees (as defined by (1) the height above ground at the attachment site, (2) the diameter of the substrate and (3) the occurrence on stem vs branches/twigs) and resembling to some extent the original Johansson zones. A sixth group of epiphytes, comprising ca. 10% of all taxa, was almost always found on small diameter stems and branches of trees with small DBH at lower and intermediate heights within the forest. Conclusions: Applying pre‐established zonation schemes may lead to misleading results in biodiversity studies with epiphytes. Important aspects of spatial distribution patterns may be missed, and the determination of relative species abundances may carry a strong quantitative and qualitative bias when analyses rely completely on epiphytic plants found on larger trees.     

Comparison of different biochemical and molecular methods for the identification of Vibrio parahaemolyticus

AIMS: Multicentre evaluation of biochemical and molecular methods for the identification of Vibrio parahaemolyticus. METHODS AND RESULTS: For the biochemical identification methods, API 20E and API 20NE and Alsina's scheme were evaluated in intra- and interlaboratory tests in order to determine the accuracy and concordance of each method. Both in intra- and interlaboratory tests, the Alsina's scheme showed the highest sensitivity (86% of correct identifications in the interlaboratory test). False-positive results were obtained by all methods (specificity was 95% for API 20E, 73% for API 20NE and 84% for Alsina's scheme) and concordance varied from 65% of API 20NE to 84% of API 20E. For the molecular identifications, polymerase chain reaction (PCR) for the detection of toxR gene, tl gene and pR72H fragment were tested on 30 strains by two laboratories. The PCR for toxR showed the highest inclusivity (96%), exclusivity (100%) and concordance (97%). CONCLUSIONS: Among the biochemical identification methods tested, the Alsina's scheme gave more reliable results; however, in order to avoid false-positive results, all the biochemical identifications should be confirmed by means of molecular methods. SIGNIFICANCE AND IMPACT OF THE STUDY: Availability of an efficient identification method of Vibrio parahaemolyticus to use in official control of fisheries products.     

tossm: an R package for assessing performance of genetic analytical methods in a management context

tossm (Testing of Spatial Structure Methods) is a package for testing the performance of genetic analytical methods in a management context. In the tossm package, any method developed to detect population genetic structure can be combined with a mechanism for creating management units (MUs) based on the genetic analysis. The resulting Boundary-Setting Algorithm (BSA) dictates harvest boundaries with a genetic basis. These BSAs can be evaluated with respect to how well the MUs they define meet management objectives.     

Solid state NMR analysis of peptides in membranes: Influence of dynamics and labeling scheme

The functional state of a membrane-active peptide is often defined by its conformation, molecular orientation, and its oligomeric state in the lipid bilayer. These “static” structural properties can be routinely studied by solid state NMR using isotope-labeled peptides. In the highly dynamic environment of a liquid crystalline biomembrane, however, the whole-body fluctuations of a peptide are also of paramount importance, although difficult to address and most often ignored. Yet it turns out that disregarding such motional averaging in calculating the molecular alignment from orientational NMR-constraints may give a misleading, if not false picture of the system. Here, we demonstrate that the reliability of a simplified static or an advanced dynamic data analysis depends critically on the choice of isotope labeling scheme used. Two distinctly different scenarios have to be considered. When the labels are placed on the side chains of a helical peptide (such as a CD₃- or CF₃-group attached to the C^αC^β bond), their nuclear spin interaction tensors are very sensitive to motional averaging. If this effect is not properly accounted for, the helix tilt angle tends to be severely underestimated. At the same time, the analysis of labels in the side chains allows to extract valuable dynamical information about whole-body fluctuations of the peptide helix in the membrane. On the other hand, the alternative labeling scheme where ¹⁵N-labels are accommodated within the peptide backbone, will yield nearly correct helix tilt angles, irrespective as to whether dynamics are taken into account or not.     

中国鸦雀的系统分类研究

本文对我国的鸦雀,提出一个新的分类系统,列有4个亚属,14种;同时还报道一个新亚种,即黄嘴鸦雀贡山亚种。从鸦雀在国内外的分布情况及棕头鸦雀亚种组的形成,推测鸦雀的起源地可能是在我国西南区的横断山脉。     

Forms of phosphorus in particulate matter from the Hollands Diep/Haringvliet,The Netherlands

The composition and the different forms of P, in an annual average sample of particulate matter, have been determined to define the nature of the very high concentration of particulate P in the inflowing water of the Hollands Diep/ Haringvliet (The Netherlands), and to assess its potential to stimulate the growth of aquatic organisms. Three phosphorus fractionation schemes and five other extraction procedures have been applied. Seventy per cent of the total phosphorus content is operationally defined as Fe- and Al-bound P but, probably, only a discreet Fe-phosphate is present, with an atomic ratio Fe/P = 1.5. About 50% of total P is present as a colloidal form (<0.45 μm). The results indicate that Murphy & Riley's procedure for orthophosphate determination causes some hydrolysis of labile organic phosphorus compounds. A fractionation scheme, to determine the different forms of P in particulate matter, is proposed. The concentration of potentially algal-available particulate P, which varies between 25 and 50 μg P 1⁻, has probably no effect on water quality because the concentration of dissolved orthophosphate (250 μg P 1⁻¹) is much higher. The huge amounts of Fe-bound P stored in the sediments, however, may retard the improvement of water quality in the future when reduction of the phosphorus loading has been accomplished.     

NUMERICAL SIMULATION OF THE PATHWAYS OF MIGRATING INSECTS

Abstract  Based on boundary layer meteorology and behavioural ecology of insect migration, a numerical TRA model was established. The spatial and temporal resolutions of the standard meteorological data are far insufficient for insect migration studies; so, a one dimension TKE closure scheme (E-ε scheme) was adopted to simulate the wind and temperature profiles en route based on the conventional surface and 850 hPa wind and temperature data of Chinese National Meteorological Bureau. Then the migrating behaviour of insects was parameterized as some proper mathematical expressions to determine their timing and their flight height, speed and direction from the wind and temperature profiles simulated by the PBL sub-model, and so their flight pathways could be estimated by a simple algorithm. Finally, the hourly episodes of the airborne migrants were output which consists of the latitude, longitude and flying altitude. The TRA model was verified by mark-release-recapture studies of Mythimna separata, Loxostege sticticalis , and Agrotis ipsilon . The results suggest that the parameterizing scheme of migratory behaviour, the numerical simulation scheme of wind and temperature in PBL and the TRA procedure developed in this paper should be reasonable and feasible. This model provides a useful tool for inter-regional forecast of migratory insect pests.     

崇明东滩湿地芦苇种群内功能性状及生态对策变异分析

植物种群功能性状及生态对策变异对其自身环境适应能力及群落结构具有重要影响。该文基于崇明东滩湿地芦苇(Phragmites australis)种群内3个小种群不同发育时期分株集合的多项性状指标,分析了其性状及生态对策变异,并基于CSR、LHS生态对策体系,对各小种群的生态对策进行了排序。结果表明, 3个芦苇小种群的21项性状指标及C、R对策得分均存在显著差异。在LHS体系中,以比叶面积(11.5 mm2/mg)、株高(175 cm)和花序干质量(4 g)为分界线,可对3个小种群进行区分。处于生殖生长期的芦苇分株具有更大的植株大小、更高的叶片干物质含量及S对策得分,而处于营养生长期的分株则具有较小的植株大小、较大的比叶面积及R对策得分。总体而言,崇明东滩湿地3个芦苇小种群间及各小种群内处于不同生长发育阶段的分株集合间,都存在显著的性状差异及生态对策差异,且二者的差异模式基本吻合。芦苇种内性状及生态对策变异特征,可为该区芦苇种群的生态保育和恢复实践提供重要的理论参考和技术支撑。     

The use of heteronuclear cross-polarization for backbone assignment of 2H-, 15N- and 13C-labeled proteins: A pulse scheme for triple-resonance 4D correlation of sequential amide protons and 15N

Summary A new four-dimensional pulse scheme is described for the main-chain assignment of proteins by means of the J connectivity of the amide proton and nitrogen resonances of adjacent residues. Since the new experiment, 4D CP-HN(COCA)NH, involves heteronuclear cross-polarization for magnetization transfer from ¹³C=O to ¹⁵N via ¹³C, a relatively strong WALTZ-16 decoupling rf field is applied to ¹³C during magnetization transfer. Consequently, ¹³C is effectively decoupled from its attached ²H in the case of deuterated proteins, in the absence of a decoupling rf field for ²H. This efficiently improves the sensitivity of the experiment through ¹³C line narrowing. The experiment was performed on a randomly 60% deuterated protein, and the sensitivity of the final 4D spectrum was found to be excellent.