Ecological restoration of rich fens in Europe and North America: from trial and error to an evidence‐based approach

Fens represent a large array of ecosystem services, including the highest biodiversity found among wetlands, hydrological services, water purification and carbon sequestration. Land‐use change and drainage has severely damaged or annihilated these services in many parts of North America and Europe; restoration plans are urgently needed at the landscape level. We review the major constraints on the restoration of rich fens and fen water bodies in agricultural areas in Europe and disturbed landscapes in North America: (i) habitat quality problems: drought, eutrophication, acidification, and toxicity, and (ii) recolonization problems: species pools, ecosystem fragmentation and connectivity, genetic variability, and invasive species; and here provide possible solutions. We discuss both positive and negative consequences of restoration measures, and their causes. The restoration of wetland ecosystem functioning and services has, for a long time, been based on a trial‐and‐error approach. By presenting research and practice on the restoration of rich fen ecosystems within agricultural areas, we demonstrate the importance of biogeochemical and ecological knowledge at different spatial scales for the management and restoration of biodiversity, water quality, carbon sequestration and other ecosystem services, especially in a changing climate. We define target processes that enable scientists, nature managers, water managers and policy makers to choose between different measures and to predict restoration prospects for different types of deteriorated fens and their starting conditions.     

Reconfiguration of a Multi-oscillator Network by Light in the Drosophila Circadian Clock

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24-Hour profiles of circulating ghrelin and peptide YY are inversely associated in normal weight premenopausal women

Peptide YY (PYY) and ghrelin (GHR) may modulate one another's actions within the hypothalamus. Peripheral infusion of PYY in humans acutely suppresses circulating concentrations of GHR. Whether an association between PYY and GHR exists in the peripheral circulation of humans over 24 h is unknown. The purpose of this study was to determine if circulating concentrations of PYY and GHR were significantly associated over 24 h in humans. Participants (n = 13) were normal weight, moderately active, women ages 18–24 yr. Blood samples were obtained q10 min for 24 h and assayed using RIA for total PYY and total GHR hourly from 0800 to 1000 h and 2000 to 0800 h and q20 min from 1000 to 2000 h. Dietary intake during the 24 h procedure was comprised of 55% carbohydrates, 30% fat, and 15% protein (three meals and a snack). Statistical analyses included linear mixed-effects modeling to test whether PYY predicted GHR concentrations over 24 h. Participants weighed 57.0 ± 1.5 kg and had 26.1 ± 1.5% body fat (15.0 ± 1.1 kg), 42.1 ± 1.1 kg fat free mass, a BMI of 21.3 ± 0.5 kg/m² and RMR of 1072 ± 28 kcal/24 h. Visually, PYY and GHR exhibited an inverse association over nearly the entire 24 h period. Statistically, circulating concentrations of 24 h PYY predicted 24 h GHR (ghrelin = 1860.51–2.14*PYY; p = 0.04). Circulating concentrations of PYY are inversely associated with GHR over 24 h. These data provide evidence that PYY may contribute to the modulation of the secretion of GHR in normal weight, premenopausal women over a 24 h period and supports similar inferences from experimental studies in animals and humans.     

Detecting invertebrate species in archived collections using next‐generation sequencing

Invertebrate biodiversity measured at mostly family level is widely used in biological monitoring programmes to assess anthropogenic impacts on ecosystems. However, next‐generation sequencing (NGS) could allow development of new more sensitive biomonitoring tools by allowing rapid species identification. This could be accelerated if archived invertebrate collections and environmental information from past programmes are used to understand species distributions and their environmental responses. In this study, we take archived macroinvertebrate samples from two sites collected on multiple occasions and test whether NGS can successfully detect species. Samples had been stored in 70% ethanol at room temperature for up to 12 years. Three amplicons ranging from 197 to 274 bps within the DNA barcode region were amplified from samples and compared to DNA barcoding libraries to identify species. We were able to amplify partial DNA barcodes from most samples, and species were often detected with multiple amplicons. However, some singletons and taxa poorly covered by DNA barcoding were missed. This suggests additional DNA barcodes will be required to fill ‘gaps’ in current DNA barcode libraries for aquatic macroinvertebrates and/or that it may not be possible to detect all taxa in a sample. Furthermore, older samples often detected fewer taxa and were less reliable for amplification, suggesting NGS is best used on samples within 8 years of collection. Nevertheless, many common taxa with existing DNA barcodes were reliably identified with NGS and were often present at sites across multiple years, showing the potential of NGS for detecting common and abundant species in archived material.     

Prefrontal cortex aspiration in pups and juvenile rats: behavioural changes and recovery of function

Male Wistar rats sustaining prefrontal cortex aspiration or sham operation at 6 days or 30 days of age were submitted to the following behavioural tests: open-field, acquisition and retention of two-way active as well as passive avoidance tasks. In the open-field the locomotor activity proved enhanced in all the aspirated animals and this enhancement lasted for 30 days. In the two-day active avoidance task, an acquisition deficit was observed in both aspirated groups; but when retrained one month later, they were able to acquire the avoidance task like sham-operated rats and no difference appeared between the groups aspirated at 6 or at 30 days of age. Concerning the passive avoidance task, no difference could be detected between aspirated and sham-operated animals of both groups except that the rats aspirated at an early age (6 days) seemed to display a better avoidance ability in the retention test. These behavioural alterations (hyperactivity and impairment of the acquisition of the 2-way active avoidance) resulted from the prefrontal cortex aspiration, at whatever age this aspiration was performed (6 days or 30 days). They disappeared after a postoperative recovery period of about one month, as evidenced by this longitudinal study.     

Polarized expression of integrin receptors (alpha 6 beta 4, alpha 2 beta 1, alpha 3 beta 1, and alpha v beta 5) and their relationship with the cytoskeleton and basement membrane matrix in cultured human keratinocytes

In human keratinocytes cultured in conditions which allow differentiation and stratification and are suitable to reconstitute a fully functional epidermis, alpha 6 beta 4 and two members of the beta 1 integrin family (alpha 2 beta 1 and alpha 3 beta 1) were respectively polarized to the basal and lateral domains of the plasmamembrane both in growing colonies and in the reconstituted epidermis. Conversely, the alpha v integrin subunit, presumably in association with beta 5, was expressed at the basal surface in growing and migrating but not in stationary keratinocytes. The integrin alpha 6 beta 4: (a) was organized in typical patches which often showed a "leopard skin" pattern where spots corresponded to microfilament-free areas; (b) was not associated with focal contacts containing vinculin and talin but rather corresponded to relatively removed contact areas of the basal membrane as shown by interference reflection microscopy; and (c) was coherent to patches of laminin secreted and deposited underneath the ventral membrane of individual cells. The two beta 1 integrins (alpha 2 beta 1 and alpha 3 beta 1), both endowed with laminin receptor properties, were not associated with focal adhesions under experimental conditions allowing full epidermal maturation but matched the lateral position of vinculin (but not talin), cingulin, and desmoplakin, all makers of intercellular junctions. Often thin strips of laminin were observed in between the lateral aspects of individual basal keratinocytes. The integrin complex alpha v beta 5 had a topography similar to that of talin- and vinculin-containing focal adhesions mostly in the peripheral cells of expanding keratinocyte colonies and in coincidence with fibronectin strands. The discrete topography of beta 1 and beta 4 integrins has a functional role in the maintenance of the state of aggregation of cultured keratinocytes since lateral aggregation was impaired by antibodies to beta 1 whereas antibodies to beta 4 prevented cell-matrix adhesion (De Luca, M., R. N. Tamura, S. Kajiji, S. Bondanza, P. Rossino, R. Cancedda, P. C. Marchisio, and V. Quaranta. Proc. Natl. Acad. Sci. USA. 87:6888-6892). Moreover, the surface polarization of integrins followed attachment and depended both on the presence of Ca2+ in the medium and on the integrity of the cytoskeleton. We conclude that our in vitro functional tests and structural data suggest a correlation between the pattern of integrin expression on defined plasmamembrane domains and the mechanism of epidermal assembly.     

Trees tolerate an extreme heatwave via sustained transpirational cooling and increased leaf thermal tolerance

Heatwaves are likely to increase in frequency and intensity with climate change, which may impair tree function and forest C uptake. However, we have little information regarding the impact of extreme heatwaves on the physiological performance of large trees in the field. Here, we grew Eucalyptus parramattensis trees for 1 year with experimental warming (+3°C) in a field setting, until they were greater than 6 m tall. We withheld irrigation for 1 month to dry the surface soils and then implemented an extreme heatwave treatment of 4 consecutive days with air temperatures exceeding 43°C, while monitoring whole‐canopy exchange of CO₂ and H₂O, leaf temperatures, leaf thermal tolerance, and leaf and branch hydraulic status. The heatwave reduced midday canopy photosynthesis to near zero but transpiration persisted, maintaining canopy cooling. A standard photosynthetic model was unable to capture the observed decoupling between photosynthesis and transpiration at high temperatures, suggesting that climate models may underestimate a moderating feedback of vegetation on heatwave intensity. The heatwave also triggered a rapid increase in leaf thermal tolerance, such that leaf temperatures observed during the heatwave were maintained within the thermal limits of leaf function. All responses were equivalent for trees with a prior history of ambient and warmed (+3°C) temperatures, indicating that climate warming conferred no added tolerance of heatwaves expected in the future. This coordinated physiological response utilizing latent cooling and adjustment of thermal thresholds has implications for tree tolerance of future climate extremes as well as model predictions of future heatwave intensity at landscape and global scales.     

Both 2',3'-dideoxythymidine and its 2',3'-unsaturated derivative (2',3'-dideoxythymidinene) are potent and selective inhibitors of human immunodeficiency virus replication in vitro

2',3'-Dideoxythymidine (ddThd) and its 2',3'-unsaturated derivative 2',3'-dideoxythymidinene (ddeThd) are potent and selective inhibitors of human immunodeficiency virus (HIV) in vitro. When evaluated for their inhibitory effects on the cytopathogenicity of HIV in MT-4 cells, ddThd and ddeThd completely protected the cells against destruction by the virus at a concentration of 1 microM and 0.04 microM, respectively. In this aspect, ddeThd was about 5 times more potent than 2',3'-dideoxycytidine (ddCyd), one of the most potent and selective anti-HIV compounds now pursued for its therapeutic potential in the treatment of AIDS. ddThd and ddeThd also suppressed HIV antigen expression at 1 microM and 0.04 microM, respectively. Their selectivity indexes, as based on the ratio of the 50% cytotoxic dose to the 50% antiviral effective dose, were 120 (ddeThd) and greater than 625 (ddThd).     

The effect of acetylene on N transformations in an acid oak-beech soil

The effectiveness of acetylene (C₂H₂) as inhibitor of nitrification was studied in relation to the decomposition of C₂H₂. This was done by examining the effects of single and multiple additions of different C₂H₂ concentrations (10, 100, 1000 Pa) on mineral N and NO₃ ^–-N production in samples of the organic (FH) and upper mineral (Ah) layer of an acid oak-beech forest soil. The decomposition of C₂H₂ was much faster in Ah samples than in FH samples. A single addition of 10 Pa C₂H₂ was not sufficient for complete inhibition of nitrification in the Ah samples. Nitrification was blocked completely by all other C₂H₂ treatments in both FH and Ah samples. Addition of C₂H₂ decreased net mineral N production in Ah samples but not in FH samples. Addition of carboxymethyl-cellulose and chitin to Ah soil had no affect on the rate of decomposition of C₂H₂. Chitin had a negative effect on net NO₃ ^–-N production.     

Assessment of Efficacy and Quality of Two Albendazole Brands Commonly Used against Soil-Transmitted Helminth Infections in School Children in Jimma Town,Ethiopia

BackgroundThere is a worldwide upscale in mass drug administration (MDA) programs to control the morbidity caused by soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura and hookworm. Although anthelminthic drugs which are used for MDA are supplied by two pharmaceutical companies through donation, there is a wide range of brands available on local markets for which the efficacy against STHs and quality remain poorly explored. In the present study, we evaluated the drug efficacy and quality of two albendazole brands (Bendex and Ovis) available on the local market in Ethiopia.Conclusion/SignificanceThe study revealed that differences in efficacy between the two brands of albendazole (ABZ) tablets against hookworm are linked to the differences in the in-vitro drug release profile. Differences in uptake and metabolism of this benzimidazole drug among different helminth species may explain that this efficacy difference was only observed in hookworms and not in the two other species. The results of the present study underscore the importance of assessing the chemical and physicochemical quality of drugs before conducting efficacy assessment in any clinical trials to ensure appropriate therapeutic efficacy and to exclude poor drug quality as a factor of reduced drug efficacy other than anthelminthic resistance. Overall, this paper demonstrates that “all medicines are not created equal”.