Scale insect allozyme differentiation within and between host trees

Summary Allelic frequencies and genotypic distributions in three polymorphic enzyme systems demonstrated genetic differentiation over extraordinarily short distances in a population of black pineleaf scale insects infesting ponderosa pine trees. A hierarchical analysis of the population genetic structure showed significant differences between demes on different twigs within individual host trees, between demes on neighboring trees, and between demes in pine plots on adjacent city blocks. Allelic frequencies at a malic enzyme locus were associated with deme-to-deme variation in ecological correlates of insect fitness, suggesting adaptive hypotheses about the causes of population subdivision.     

CCR5 antagonist TD-0680 uses a novel mechanism for enhanced potency against HIV-1 entry, cell-mediated infection, and a resistant variant

Regardless of the route of transmission, R5-tropic HIV-1 predominates early in infection, rendering C-C chemokine receptor type 5 (CCR5) antagonists as attractive agents not only for antiretroviral therapy but also for prevention. Here, we report the specificity, potency, and underlying mechanism of action of a novel small molecule CCR5 antagonist, TD-0680. TD-0680 displayed the greatest potency against a diverse group of R5-tropic HIV-1 and SIV strains when compared with its prodrug, TD-0232, the Food and Drug Administration-approved CCR5 antagonist Maraviroc, and TAK-779, with EC(50) values in the subnanomolar range (0.09-2.29 nm). Importantly, TD-0680 was equally potent at blocking envelope-mediated cell-cell fusion and cell-mediated viral transmission as well as the replication of a TAK-779/Maraviroc-resistant HIV-1 variant. Interestingly, TD-0232 and TD-0680 functioned differently despite binding to a similar transmembrane pocket of CCR5. Site-directed mutagenesis, drug combination, and antibody blocking assays identified a novel mechanism of action of TD-0680. In addition to binding to the transmembrane pocket, the unique exo configuration of this molecule protrudes and sterically blocks access to the extracellular loop 2 (ECL2) region of CCR5, thereby interrupting the interaction between virus and its co-receptor more effectively. This mechanism of action was supported by the observations of similar TD-0680 potency against CD4-dependent and -independent SIV strains and by molecular docking analysis using a CCR5 model. TD-0680, therefore, merits development as an anti-HIV-1 agent for therapeutic purposes and/or as a topical microbicide for the prevention of sexual transmission of R5-tropic HIV-1.     

Angiotensin-converting enzyme insertion/deletion polymorphism and risk of myocardial infarction in an updated meta-analysis based on 34 993 participants

The association between angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of myocardial infarction (MI) has been extensively studied. However, the results were in controversy. This study aimed to explore the association between ACE I/D polymorphism and risk of MI by using a meta-analysis. We retrieved the following databases to indentify eligible studies: Medline, Embase, ISI, VIP, CBM and Wan Fang database. The latest update was 10th May, 2012. Odds ratio and 95% confidence interval (95% CI) were used to present the strength of the association. A total of 40 case–control studies with 34 993 participants were included. Overall, D allele of ACE I/D polymorphism was significantly associated with an increased risk of MI in genetic comparison models (OR (95% CI): 1.41 (1.22–1.64) for DD vs. II; 1.11 (1.01–1.21) for ID vs. II; 1.23 (1.10–1.37) for D carriers vs. II; 1.28 (1.15–1.43) for DD vs. I carriers and 1.06 (1.02–1.10) for D carriers vs. I carriers). Subgroup analyses, according to ethnicities and countries of participants also indicated that D allele was significantly associated with an increased risk of MI in Asians (especially for Chinese) and Caucasians (especially for English, French, Germans and Italians) (OR (95% CI) of DD vs. ID + II: 2.11 (1.65–2.70) for Asians and 1.15 (1.05–1.27) for Caucasians). In conclusion, this meta-analysis indicated that D allele of ACE I/D polymorphism was a possible risk factor for MI incidence for both Asians and Caucasians.     

Fractal properties of forest spatial structure

The definition of fractal dimension of natural objects, which enables to deal with scale dependence of fractal dimension is discussed. Abrupt changes of fractal dimension of spatial structure of terrestrial ecosystems are considered in the context of hierarchical paradigm. On this ground the procedure is proposed for segmentation of a territory, which takes into account the scale dependence of spatial variability of ecological parameters. Using remotely sensed data — normalized difference vegetation index (NDVI) and thermal radiation in the infrared band — fractal dimensions and critical scales are evaluated for different forest types with the help of software, developed for this purpose. The results obtained corroborate the potentialities of fractal approach in ecology. These methods and results can be used for discrimination of remotely sensed data; but further investigations, including detailed comparison of fractal characteristics of remotely sensed forest images with results of on-site field studies are necessary to validate them.     

Histology of Polypterus senegalus fin rays revisited

The present comparative histological study of the pectoral, caudal and anal fins of the polypterid Polypterus senegalus reveals the presence of a layer of dentine identified between the superficial ganoine patches and the bony part of the lepidotrichia in the three fins. Its extent varies depending on the fins. Similarly, the ganoine layer present at the surface of the proximal lepidotrichia shows fin-dependent differences in extent and distribution. The dentine layer is crossed by a system of thin worm-like vascular canaliculi that reach the ganoine layer and even penetrate within it as in the scales. In the lepidotrichia, the dentine lays directly on bone, which differs from the scales where dentine lies on isopedine, a plywood-like structure. Another difference between scales and lepidotrichia is the presence of actinotrichia that are unmineralised, fusiform rods of elastoidine located at the tip of the fins. Ontogenesis with differentiation of actinotrichia has no equivalent in scale formation. Although structural features are shared by lepidotrichia and scales in P. senegalus, observations on the scales and lepidotrichia support the hypothesis of Schaeffer (1977) that “scales and lepidotrichia are somewhat differently shaped manifestations of the same morphogenetic system”.     

Elevated pCO2 affects the lactate metabolic shift in CHO cell culture processes

The shift from lactate production to consumption in CHO cell metabolism is a key event during cell culture cultivations and is connected to increased culture longevity and final product titers. However, the mechanisms controlling this metabolic shift are not yet fully understood. Variations in lactate metabolism have been mainly reported to be induced by process pH and availability of substrates like glucose and glutamine. The aim of this study was to investigate the effects of elevated pCO₂ concentrations on the lactate metabolic shift phenomena in CHO cell culture processes. In this publication, we show that at elevated pCO₂ in batch and fed‐batch cultures, the lactate metabolic shift was absent in comparison to control cultures at lower pCO₂ values. Furthermore, through metabolic flux analysis we found a link between the lactate metabolic shift and the ratio of NADH producing and regenerating intracellular pathways. This ratio was mainly affected by a reduced oxidative capacity of cultures at elevated pCO₂. The presented results are especially interesting for large‐scale and perfusion processes where increased pCO₂ concentrations are likely to occur. Our results suggest, that so far unexplained metabolic changes may be connected to increased pCO₂ accumulation in larger scale fermentations. Finally, we propose several mechanisms through which increased pCO₂ might affect the cell metabolism and briefly discuss methods to enable the lactate metabolic shift during cell cultivations.     

Corneal antifibrotic switch identified in genetic and pharmacological deficiency of vimentin

The type III intermediate filaments (IFs) are essential cytoskeletal elements of mechanosignal transduction and serve critical roles in tissue repair. Mice genetically deficient for the IF protein vimentin (Vim(-/-)) have impaired wound healing from deficits in myofibroblast development. We report a surprising finding made in Vim(-/-) mice that corneas are protected from fibrosis and instead promote regenerative healing after traumatic alkali injury. This reparative phenotype in Vim(-/-) corneas is strikingly recapitulated by the pharmacological agent withaferin A (WFA), a small molecule that binds to vimentin and down-regulates its injury-induced expression. Attenuation of corneal fibrosis by WFA is mediated by down-regulation of ubiquitin-conjugating E3 ligase Skp2 and up-regulation of cyclin-dependent kinase inhibitors p27(Kip1) and p21(Cip1). In cell culture models, WFA exerts G(2)/M cell cycle arrest in a p27(Kip1)- and Skp2-dependent manner. Finally, by developing a highly sensitive imaging method to measure corneal opacity, we identify a novel role for desmin overexpression in corneal haze. We demonstrate that desmin down-regulation by WFA via targeting the conserved WFA-ligand binding site shared among type III IFs promotes further improvement of corneal transparency without affecting cyclin-dependent kinase inhibitor levels in Vim(-/-) mice. This dissociates a direct role for desmin in corneal cell proliferation. Taken together, our findings illuminate a previously unappreciated pathogenic role for type III IF overexpression in corneal fibrotic conditions and also validate WFA as a powerful drug lead toward anti-fibrosis therapeutic development.     

Anatomical differentiation of isolated scales of amiiform fishes (Amiiformes,Actinopterygii) from the Early Cretaceous of Las Hoyas (Cuenca,Spain)

The scales of amiiform fishes are more different from each other than previously stated. The anatomy of the scales of the three amiiform taxa from the Early Cretaceous (Barremian) of Las Hoyas (Cuenca, Spain) is described in detail. The differences between them has allowed the segregation of isolated scales form the fossil record of this site into the three taxa, providing relatively large population samples that can be studied from a palaeobiological and palaeoecological point of view.     

Mechanical-Statistical Modeling in Ecology: From Outbreak Detections to Pest Dynamics

Knowledge about large-scale and long-term dynamics of (natural) populations is required to assess the efficiency of control strategies, the potential for long-term persistence, and the adaptability to global changes such as habitat fragmentation and global warming. For most natural populations, such as pest populations, large-scale and long-term surveys cannot be carried out at a high resolution. For instance, for population dynamics characterized by irregular abundance explosions, i.e., outbreaks, it is common to report detected outbreaks rather than measuring the population density at every location and time event. Here, we propose a mechanical-statistical model for analyzing such outbreak occurrence data and making inference about population dynamics. This spatio-temporal model contains the main mechanisms of the dynamics and describes the observation process. This construction enables us to account for the discrepancy between the phenomenon scale and the sampling scale. We propose the Bayesian method to estimate model parameters, pest densities and hidden factors, i.e., variables involved in the dynamics but not observed. The model was specified and used to learn about the dynamics of the European pine sawfly (Neodiprion sertifer Geoffr., an insect causing major defoliation of pines in northern Europe) based on Finnish sawfly data covering the years 1961–1990. In this application, a dynamical Beverton–Holt model including a hidden regime variable was incorporated into the model to deal with large variations in the population densities. Our results gave support to the idea that pine sawfly dynamics should be studied as metapopulations with alternative equilibria. The results confirmed the importance of extreme minimum winter temperatures for the occurrence of European pine sawfly outbreaks. The strong positive connection between the ratio of lake area over total area and outbreaks was quantified for the first time.     

A flexible multi-scale approach for standardised recording of plant species richness patterns

A sound monitoring of appropriate biodiversity indicators is necessary in order to assess the progress towards the internationally agreed target of halting the loss of biodiversity by 2010. However, existing monitoring schemes often do not address species richness as a key component of biodiversity directly or do so with insufficient methods. I provide an overview and assessment of the large variety of different sampling approaches for small-scale plant species richness. Major shortcomings of many of these are (i) non-uniform plot sizes or shapes; (ii) analysis of only one spatial scale despite the scale dependence of nearly all biodiversity parameters; (iii) lack of replication of smaller subplots; and (iv) exclusion of bryophytes and lichens despite their often large contribution to total plant diversity. Based on this review, I propose a new standardised sampling approach for plant diversity patterns at small scales that is applicable for a multitude of purposes and in any biome. In its basic variant, species composition is recorded on nested squares of 0.01 m², 0.1 m², 1 m², 10 m², and 100 m², with all smaller subplots being replicated at least 3-fold and evenly spaced within the next larger plot. Not only terricolous vascular plants, but also bryophytes, lichens, macro-algae as well as non-terricolous taxa should be recorded with the any-part system, i.e. those plants are counted within a plot whose superficial parts reach over it. This approach can be used to assess plant diversity patterns (i) of individual plots of interest, (ii) along environmental gradients, (iii) within specific vegetation types, or (iv) for landscape sectors. In the latter case, the series of nested plots must be placed randomly or systematically, but irrespective of plot homogeneity. The proposed approach allows the calculation of many meaningful biodiversity indicators, while being well compatible with a range of other sampling schemes, but avoiding their shortcomings. As this approach is not very time-consuming in its basic variant, but can easily be extended for specific purposes, I suggest its use for any kind of biodiversity studies and particularly for monitoring.