Relative contribution of edge and interior zones to patch size effect on species richness: An example for woody plants

In order to understand the capacity of habitats to conserve species, many authors have searched for a species–area relationship (SAR) to evaluate the effect of patch size on species richness in habitat fragments. However, a range of different processes may underlie or obscure this relationship. For woody plant species in forest fragments, as for other taxa, considering forest edges separately in the investigation of SAR is particularly relevant. The objective of our study was to evaluate edge influence on SAR in a fragmented forest landscape in south-western France. To achieve this objective, we considered SAR in two separate spatial portions of the forest fragment: the edge and the forest interior. We also considered SAR for different ecological groups of species based on their shade tolerance and their mode of dispersal, as species can respond differently to habitat reduction depending on their ecological characteristics. In 40 woodlands in an agricultural landscape, we observed the presence/absence of all woody species along parallel walking transects 20-m wide to inventory the total number of species in each woodlot. Vegetation surveys resulted in the identification of 53 woody species, with a total of 23 trees and 30 shrubs, and a number of species per woodlot ranging from 18 to 44. The species richness found in a given woodlot was significantly correlated with its area. When considering the edge and the interior parts of the woodlot separately we found a steeper increase in species richness with area for the part we considered as the edge, compared with the increase found in the interior part of the forest. Our results confirm the contribution of forest edge to forest fragment SAR. Results also underlined the importance of two additional processes that may contribute to SAR: a possible extinction debt of shade-tolerant species in forest edge zones and colonisation by light-demanding species in forest interior zones probably due to disturbances. This approach underlines the importance of taking the edge effect into account when studying the influence of patch size on species richness and the dynamic of species richness pattern.     

RSK1 vs. RSK2 Inhibitory Activity of the Marine β-Carboline Alkaloid Manzamine A: A Biochemical,Cervical Cancer Protein Expression,and Computational Study

Manzamines are complex polycyclic marine-derived β-carboline alkaloids with reported anticancer, immunostimulatory, anti-inflammatory, antibacterial, antiviral, antimalarial, neuritogenic, hyperlipidemia, and atherosclerosis suppression bioactivities, putatively associated with inhibition of glycogen synthase kinase-3, cyclin-dependent kinase 5, SIX1, and vacuolar ATPases. We hypothesized that additional, yet undiscovered molecular targets might be associated with Manzamine A’s (MZA) reported pharmacological properties. We report here, for the first time, that MZA selectively inhibited a 90 kDa ribosomal protein kinase S6 (RSK1) when screened against a panel of 30 protein kinases, while in vitro RSK kinase assays demonstrated a 10-fold selectivity in the potency of MZA against RSK1 versus RSK2. The effect of MZA on inhibiting cellular RSK1 and RSK2 protein expression was validated in SiHa and CaSki human cervical carcinoma cell lines. MZA’s differential binding and selectivity toward the two isoforms was also supported by computational docking experiments. Specifically, the RSK1-MZA (N- and C-termini) complexes appear to have stronger interactions and preferable energetics contrary to the RSK2–MZA ones. In addition, our computational strategy suggests that MZA binds to the N-terminal kinase domain of RSK1 rather than the C-terminal domain. RSK is a vertebrate family of cytosolic serine-threonine kinases that act downstream of the ras-ERK1/2 (extracellular-signal-regulated kinase 1/2) pathway, which phosphorylates substrates shown to regulate several cellular processes, including growth, survival, and proliferation. Consequently, our findings have led us to hypothesize that MZA and the currently known manzamine-type alkaloids isolated from several sponge genera may have novel pharmacological properties with unique molecular targets, and MZA provides a new tool for chemical-biology studies involving RSK1.     

Moroccan Forestry Policies and Local Forestry Management in the High Atlas: A Cross Analysis of Forestry Administration and Local Institutions

This paper examines how local forestry management has evolved in the Aït Bougmez Valley (Central High Atlas, Morocco) in the last three decades and how this evolution has affected forest ecosystem conditions. It focuses on the impact of the forestry administration on ‘traditional forestry management’ since its introduction in 1985, and of recent innovation in forestry policy. The relatively new Strategic Environmental Management Analysis (SEMA) framework is applied, rather than a more ‘classical’ new institutional framework. This approach allows for a more comprehensive understanding of both strategic interactions between various actors and ecological consequences of these interactions. An interesting empirical findings is that instead of a quite simple opposition between the forestry administration and local populations, negotiation opportunities exist that are taken by the actors. This leads to specific actor configurations and sometimes unexpected environmental outcomes, even if from a global point of view, forest stands have been seriously depleted over the last 40 years mainly due to exploitation by local population and the absence of economic alternative to forest exploitation. On the other hand, the implementation of a new policy tool in such a context has to be understood as an opportunity for new actors to take part in forest management rules definition.     

Managing Amazonian palms for community use: A case of aguaje palm (Mauritia flexuosa) in Peru

Amazonian palms are prime candidates for sustainable management of non-timber forest products and yet useful species are often harvested destructively. This paper examines a promising management initiative for one of the most useful Amazonian palms – Mauritia flexuosa – in a rural community of northeastern Peru. Based on data from household surveys (n = 57), filmed in-depth interviews, focus groups and participant observation, we identify the factors that influence: (1) the adoption of a locally developed climbing device for wild-harvesting of aguaje palm fruit; (2) the continued practice by some households of palm felling for harvesting fruit; and, (3) investment by households in planting and cultivation of aguaje palm. Our findings identify key conditions for palm management and point to the particular importance of the adoption of palm-climbing devices, not only for reducing wild palm felling but also for stimulating broader community-level conservation as well as efforts to cultivate the palm.     

Chronic mucocutaneous candidiasis in humans with inborn errors of interleukin-17 immunity

Chronic mucocutaneous candidiasis disease (CMCD) is characterized by recurrent or persistent infections of the skin, nails, and oral and genital mucosae caused by Candida albicans and, to a lesser extent, Staphylococcus aureus, in patients with no other infectious or autoimmune manifestations. We report two genetic etiologies of CMCD: autosomal recessive deficiency in the cytokine receptor, interleukin-17 receptor A (IL-17RA), and autosomal dominant deficiency of the cytokine interleukin-17F (IL-17F). IL-17RA deficiency is complete, abolishing cellular responses to IL-17A and IL-17F homo- and heterodimers. By contrast, IL-17F deficiency is partial, with mutant IL-17F-containing homo- and heterodimers displaying impaired, but not abolished, activity. These experiments of nature indicate that human IL-17A and IL-17F are essential for mucocutaneous immunity against C. albicans, but otherwise largely redundant.     

Dissolved nitrogen model for paddy field ponded water during irrigation period

Based on an experimental field study in Japan, a model was developed to simulate dissolved nitrogen in water ponded in a paddy field. As input data, the model uses meteorological data, water balance in the field, nitrogen concentration in inlet water, and the nitrogen contribution of applied fertilizer. Five model parameters need calibration. A practical application of the model is the simulation of NH₄-N and NO₂₊₃-N concentrations in water ponded in a paddy field. The model improves our understanding of the interactions between forms of dissolved nitrogen in ponded water and can explain the complex changes in dissolved nitrogen concentrations in water ponded on a paddy field.     

Association of dhurrin levels and post-flowering non-senescence with resistance to stalk rot pathogens in Sorghum bicolor

European Journal of Plant Pathology - Aflatoxin contamination is common in several crops, including maize, in warm agricultural areas. For over 40 years, there have been many efforts to...     

First report of dry rot of potato caused by Fusarium proliferatum in India

Journal of Plant Diseases and Protection - Potato stands first as a non-cereal food crop for global consumption purposes. During the year 2019–20, dry rot disease symptoms were observed on...