Planktonic indices in the evaluation of the ecological status and the trophic state of the longest lake in Poland

Due to the intensive mixing polymictic lakes should be homogenous. However, morphometric diversity and high water dynamics contribute to the differentiation of many parameters in various areas of the lakes. This study analyzes both phytoplankton and zooplankton to assess differences in water quality along the north–south axis of the longest lake in Poland. New phytoplankton indicators were applied for determining the lake's ecological status: the Q index based on functional groups and the PMPL (Phytoplankton Metric for Polish Lakes) index based on phytoplankton biomass. TSI_ROT index (Rotifer Trophic State Index), which comprises the percentage of species indicating a high trophic state in the indicatory group and the percentage of bacteriovorus in the Rotifera population, was used for zooplankton analysis.TP content was different at different sites – we observed its gradual increase from the south to the north. Spatial variation of phosphorus did not considerably affect plankton diversity. The phytoplankton was dominated by Oscillatoriales, typical of shallow, well-mixed eutrophic lakes. The ecological status of the lake based on the EQR (Ecological Quality Ratio) was poor or moderate. The zooplankton was dominated by rotifers (at almost all sites), which indicates a eutrophic state of the lake. The values of phytoplankton indices at the studied sites did not differ considerably; the differences resulted more from local conditions such as the contaminant inflow and the macrophyte development than water dynamics.We have demonstrated that in the lake dominated by filamentous Cyanobacteria the ecological status should be determined according to the PMPL index or other indices dependent on the dominant Cyanobacteria species. Since the Q index does not include the functional group S1, the results can lead to the false conclusion that water quality improves with an increased amount of phytoplankton. The high abundance of Cyanobacteria in the lake may have contributed to the poor growth of rotifers.     

A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in‐field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in‐field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.     

New t‐butyl based aspartate protecting groups preventing aspartimide formation in Fmoc SPPS

Obtaining homogenous aspartyl‐containing peptides via Fmoc/tBu chemistry is often an insurmountable obstacle. A generic solution for this issue utilising an optimised side‐chain protection strategy that minimises aspartimide formation would therefore be most desirable. To this end, we developed the following new derivatives: Fmoc‐Asp(OEpe)‐OH (Epe = 3‐ethyl‐3‐pentyl), Fmoc‐Asp(OPhp)‐OH (Php = 4‐n‐propyl‐4‐heptyl) and Fmoc‐Asp(OBno)‐OH (Bno = 5‐n‐butyl‐5‐nonyl). We have compared their effectiveness against that of Fmoc‐Asp(OtBu)‐OH and Fmoc‐Asp(OMpe)‐OH in the well‐established scorpion toxin II model peptide variants H‐Val‐Lys‐Asp‐Asn/Arg‐Tyr‐Ile‐OH by treatments of the peptidyl resins with the Fmoc removal reagents containing piperidine and DBU at both room and elevated temperatures. The new derivatives proved to be extremely effective in minimising aspartimide by‐products in each application. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.     

Purification and properties of indole 2,3-dioxygenase from maize leaves

An indole 2,3-dioxygenase was purified ca 38-fold from maize leaves. The enzyme had an MW of about 98000, an optimum pH of 5.0 and the energy of activation was 9.1 kcal/mol. The K_max for indole was 1.4 × 10^?4 M. The enzyme was inhibited by diethyldithiocarbamate, salicylaldoxime and sodium dithionite. The inhibition by diethyldithiocarbamate was specifically reversed by Cu²⁺. The dialysed enzyme was stimulated by Cu²⁺. Four atoms of oxygen were utilized in the disappearance of 1 mole of indole. Inhibition of the enzyme by -SH compounds and -SH group inhibitors, and their partial removal by Cu²⁺ only, suggested the involvement of -SH groups in binding of Cu²⁺ at the catalytic site.     

华北地区汉族的Lewis、ABO、MN、Rh、P等血型系统和ABH分泌型的分布

调查了原籍华北地区汉族的ABO、Lewis、MN、Rh、P等血型系统和ABH分泌型的分布,结果表明:O型(33.44％)和B型(29.38％)较多;N型(27.97％)略多于M型(27.65％);Le(a )型的频率很高(24.17％)。在94人中还发现四名Le(a )型属于ABH分泌型,且都属于分泌A或B血型物质的类型,无一例为分泌H血型物质的类型;Rh(D)阴性率仅0.3％,CCDee和CcDE型占75％以上;P_1( )型占39.1％;ABH分泌型占72％,低于全国其他民族中已知的分布。     

Chemoselective N-Deacetylation of Protected Nucleosides and Nucleotides Promoted by Schwartz's Reagent

Protection and deprotection strategies involving the N-acetyl group are widely utilized in nucleoside and nucleotide chemistry. Herein, we present a mild and selective N-deacetylation methodology, applicable to purine and pyrimidine nucleosides, by means of Schwartz's reagent, compatible with most of the common protecting groups used in nucleoside chemistry.     

Diet composition in San Francisco Estuary striped bass: does trophic adaptability have its limits?

Trophic adaptability is a term used to describe feeding flexibility in fishes. Though a useful conceptual starting point, fishes often face constraints on their ability to switch prey that could limit feeding success even when prey switching is observed. We compared striped bass diet compositions summarized from previously published studies in California’s Sacramento-San Joaquin Delta during two time periods (1963–1964 and 2001–2003), which allowed us to evaluate trophic adaptability in San Francisco Estuary striped bass at multiple time scales, ranging from intra-annual to multidecadal. The Delta is the landward region of the San Francisco Estuary; over time between the study periods, the Delta underwent substantial changes in potential prey availability for striped bass. We found evidence for trophic adaptability in San Francisco Estuary (SFE) striped bass at all temporal scales examined. Despite this ability to adapt to changes in prey availability, the relative abundance and carrying capacity of young striped bass have declined. This decline has previously been associated with substantial declines in their dominant historical prey—mysid shrimp. Our results, coupled with these previous findings, indicate that trophic adaptability may have limited usefulness as a conceptual model to predict foraging success when other food web constraints are not considered. We speculate that this is particularly true in highly invaded ecosystems like the San Francisco Estuary because invading species often introduce substantial and permanent changes into food webs, decreasing the likelihood that a predator will find prey assemblages that fully replace historical prey assemblages.     

Bird based Index of Biotic Integrity: Assessing the ecological condition of Atlantic Forest patches in human-modified landscape

Wooded biomes converted to human-modified landscapes (HML) are common throughout the tropics, yielding small and isolated forest patches surrounded by an agricultural matrix. Diverse anthropogenic interventions in HMLs influence patches in complex ways, altering natural dynamics. Assessing current condition or ecological integrity in these patches is a challenging task for ecologists. Taking the Brazilian Atlantic Forest as a case study, we used the conceptual framework of the Index of Biotic Integrity (IBI), a multimetric approach, to assess the ecological integrity of eight small forest patches in a highly disturbed HML with different configurations and histories. The IBI was developed using bird assemblages found in these patches, and its performance was compared with analytical approaches commonly used in environmental assessment, such as general richness and Shannon’s diversity index. As a first step, the IBI procedure identifies an existing gradient of human disturbance in the study region and checks which biotic characteristics (candidate metrics) vary systematically across the gradient. A metric is considered valid when its’ relationship with the gradient provides an ecological interpretation of the environment. Then, the final IBI is elaborated using each valid metric, obtaining a score for each site. Over one year of sampling, 168 bird species were observed, providing 74 different bird candidate metrics to be tested against the disturbance gradient. Seven of them were considered valid:richness of threatened species; richness of species that use both “forest and non-forest” habitats; abundance of endemics, abundance of small understory-midstory insectivores, abundance of exclusively forest species; abundance of non-forest species, and abundance of species that forage exclusively in the midstory stratum. Each metric provided complementary information about the patch’s ecological integrity. The resulting IBI showed a significant linear relationship with the gradient of human disturbance, while total species richness and Shannońs diversity index did not. Application of numerical approaches, such as total species richness and Shannon’s diversity, did not distinguish ecological traits among species. The IBI proved better for assessing and interpreting ecological and environmental condition of small patches in highly disturbed HML. The IBI framework, its multimetric character, and the ease with which it can be adapted to diverse situations, make it an effective approach for assessing environmental conditions in the Atlantic Forest region, and also for many other small forest patches in the tropics.