Assessing sedimentological connectivity using WATEM/SEDEM model in a hilly and gully watershed of the Loess Plateau,China

Sedimentological connectivity is an important issue in soil erosion and sediment transport. Landscape patterns, in combination with the rainfall regime, are known to shape such sedimentological connectivity. The quantification of sedimentological connectivity provides a link between sediment delivery and landscape pattern. There are two categories of connectivity: structural connectivity, which describes the physical coupling of landscape units, and functional connectivity, which delineates the linkage among landscape elements maintained by material transport. To quantify sedimentological connectivity, both the physical coupling of, and material transfer between, the various landscape components need to be assessed. This study quantifies the sedimentological connectivity of a headwater catchment in the Loess Plateau of China using the soil erosion and sediment delivery model (WATEM/SEDEM). Based on the model, two indicators of connectivity were developed: the area of sedimentologically effective catchment area (SEA) that contributes sediment to the sinks, and the minimum sediment output of locations on the flow path that link sources and sinks. This approach effectively represents the annual status of catchment-scale sedimentological connectivity and, furthermore, the simple structure and readily available input data make it highly practicable. However, for larger river systems in which sediment transport between sources and sinks occur over longer time scales and larger spatial scales, we suggest different techniques for quantifying the sediment flux and parameters delineating the physical coupling of landscape units.     

A novel Golgi mannosidase inhibitor: Molecular design,synthesis, enzyme inhibition,and inhibition of spheroid formation

Effective chemotherapy for solid cancers is challenging due to a limitation in permeation that prevents anticancer drugs from reaching the center of the tumor, therefore unable to limit cancer cell growth. To circumvent this issue, we planned to apply the drugs directly at the center by first collapsing the outer structure. For this, we focused on cell–cell communication (CCC) between N-glycans and proteins at the tumor cell surface. Mature N-glycans establish CCC; however, CCC is hindered when numerous immature N-glycans are present at the cell surface. Inhibition of Golgi mannosidases (GMs) results in the transport of immature N-glycans to the cell surface. This can be employed to disrupt CCC. Here, we describe the molecular design and synthesis of an improved GM inhibitor with a non-sugar mimic scaffold that was screened from a compound library. The synthesized compounds were tested for enzyme inhibition ability and inhibition of spheroid formation using cell-based methods. Most of the compounds designed and synthesized exhibited GM inhibition at the cellular level. Of those, AR524 had higher inhibitory activity than a known GM inhibitor, kifunensine. Moreover, AR524 inhibited spheroid formation of human malignant cells at low concentration (10 µM), based on the disruption of CCC by GM inhibition.     

Occurrence of Potentially Pathogenic Bacteria in Epilithic Biofilm Forming Bacteria isolated from Porter Brook River-stones,Sheffield, UK

Biofilms in aquatic ecosystems develop on wet benthic surfaces and are primarily comprised of various allochthonous microorganisms, including bacteria embedded within a self-produced matrix of extracellular polymeric substances (EPS). In such environment, where there is a continuous flow of water, attachment of microbes to surfaces prevents cells being washed out of a suitable habitat with the added benefits of the water flow and the surface itself providing nutrients for growth of attached cells. When watercourses are contaminated with pathogenic bacteria, these can become incorporated into biofilms. This study aimed to isolate and identify the bacterial species within biofilms retrieved from river-stones found in the Porter Brook, Sheffield based on morphological, biochemical characteristics and molecular characteristics, such as 16S rDNA sequence phylogeny analysis. Twenty-two bacterial species were identified. Among these were 10 gram-negative pathogenic bacteria, establishing that potential human pathogens were present within the biofilms. Klebsiella pneumoniae MBB9 isolate showed the greatest ability to form a biofilm using a microtiter plate-based crystal violet assay. Biofilm by K. pneumoniae MBB9 formed rapidly (within 6 h) under static conditions at 37 °C and then increased up to 24 h of incubation before decreasing with further incubation (48 h), whereas the applied shear forces (horizontal orbital shaker; diameter of 25 mm at 150 rpm) had no effect on K. pneumoniae MBB9 biofilm formation.     

Identification and comprehensive analysis of the CLV3/ESR‐related (CLE) gene family in Brassica napus L.

• The CLE (CLAVATA3/ESR) gene family, encoding a group of small secretory peptides, plays important roles in cell‐to‐cell communication, thereby controlling a broad spectrum of development processes. The CLE family has been systematically characterized in some plants, but not in Brassica napus.
• In the present study, 116 BnCLE genes were identified in the B. napus genome, including seven unannotated, six incorrectly predicted and five multi‐CLE domain‐encoding genes. These BnCLE members were separated into seven distinct groups based on phylogenetic analysis, which might facilitate the functional characterization of the peptides.
• Further characterization of CLE pre‐propeptides revealed 31 unique CLE peptides from 45 BnCLE genes, which may give rise to distinct roles of BnCLE and expansion of the gene family. The biological activity of these unique CLE dodecamer peptides was tested further through in vitro peptide assays. Variations in several important residues were identified as key contributors to the functional differentiation of BnCLE and expansion of the gene family in B. napus. Expression profile analysis helped to characterize possible functional redundancy and sub‐functionalization among the BnCLE members.
• This study presents a comprehensive overview of the CLE gene family in B. napus and provides a foundation for future evolutionary and functional studies.

     

Downscaling indicators of forest habitat structure from national assessments

Downscaling is an important problem because consistent large-area assessments of forest habitat structure, while feasible, are only feasible when using relatively coarse data and indicators. Techniques are needed to enable more detailed and local interpretations of the national statistics. Using the results of national assessments from land-cover maps, this paper demonstrates downscaling in the spatial domain, and in the domain of the habitat model. A moving window device was used to measure structure (habitat amount and connectivity), and those indicators were then analyzed and combined with other information in various ways to illustrate downscaling.     

Anatomical site of pheromone accumulation and temporal pattern of pheromone emission in the ambrosia beetle Megaplatypus mutatus

Megaplatypus mutatus (Chapuis) is a native South American ambrosia beetle that attacks live hardwood trees (e.g. Populus spp.), causing important economic losses to commercial plantations. Male beetles release the main components of the sex pheromone, namely (+)‐6‐methyl‐5‐hepten‐2‐ol [(+)‐sulcatol, or retusol] and 6‐methyl‐5‐hepten‐2‐one (sulcatone), when colonizing suitable hosts. The hindgut is shown to be the anatomical site of pheromone accumulation within males, the enantiomeric composition of sulcatol in this tissue is 99%‐(+) and sulcatol is first detectable in this tissue on days 1–2 after gallery initiation. Peak accumulation of sulcatol occurs on days 5–12 after gallery initiation. Trace quantities of sulcatone are also observed during the same period. Both pheromone components are present in male emissions from three host species (Populus×canadensis, Populus alba and Casuarina stricta) between days 2 and 12 after gallery initiation, although sulcatone is always present in low concentrations. The temporal patterns of sulcatol and sulcatone accumulation or storage in male M. mutatus correspond to the temporal patterns of emission.