Search results for "IgA"
showing 10 items of 7335 documents
Regional endothermy as a trigger for gigantism in some extinct macropredatory sharks
2017
Otodontids include some of the largest macropredatory sharks that ever lived, the most extreme case being Otodus (Megaselachus) megalodon. The reasons underlying their gigantism, distribution patterns and extinction have been classically linked with climatic factors and the evolution, radiation and migrations of cetaceans during the Paleogene. However, most of these previous proposals are based on the idea of otodontids as ectothermic sharks regardless of the ecological, energetic and body size constraints that this implies. Interestingly, a few recent studies have suggested the possible existence of endothermy in these sharks thus opening the door to a series of new interpretations. Accord…
Eye fluke-induced cataracts in natural fish populations: is there potential for host manipulation?
2010
SUMMARYManipulation of host phenotype (e.g. behaviour, appearance) is suggested to be a common strategy to enhance transmission in trophically transmitted parasites. However, in many systems, evidence of manipulation comes exclusively from laboratory studies and its occurrence in natural host populations is poorly understood. Here, we examined the potential for host manipulation by Diplostomum eye flukes indirectly by quantifying the physiological effects of parasites on fish. Earlier laboratory studies have shown that Diplostomum infection predisposes fish to predation by birds (definitive hosts of the parasites) by reducing fish vision through cataract formation. However, occurrence of ca…
Long-term carbon stock recovery in a neotropical-logged forest
2019
AbstractThis article assesses the effect of different logging levels on loss of above-ground biomass and the contribution of different ecological groups of species in the long-term recovery of C st...
A niche perspective on the range expansion of symbionts.
2020
Range expansion results from complex eco-evolutionary processes where range dynamics and niche shifts interact in a novel physical space and/or environment, with scale playing a major role. Obligate symbionts (i.e. organisms permanently living on hosts) differ from free-living organisms in that they depend on strong biotic interactions with their hosts which alter their niche and spatial dynamics. A symbiotic lifestyle modifies organism–environment relationships across levels of organisation, from individuals to geographical ranges. These changes influence how symbionts experience colonisation and, by extension, range expansion. Here, we investigate the potential implications of a symbiotic…
No growth stimulation of Canada’s boreal forest under half-century of combined warming and CO 2 fertilization
2016
Considerable evidence exists that current global temperatures are higher than at any time during the past millennium. However, the long-term impacts of rising temperatures and associated shifts in the hydrological cycle on the productivity of ecosystems remain poorly understood for mid to high northern latitudes. Here, we quantify species-specific spatiotemporal variability in terrestrial aboveground biomass stem growth across Canada’s boreal forests from 1950 to the present. We use 873 newly developed tree-ring chronologies from Canada’s National Forest Inventory, representing an unprecedented degree of sampling standardization for a large-scale dendrochronological study. We find significa…
Integrative effects of vine water relations and grape ripeness level of vitis vinifera L. cv. Shiraz/Richter 99. II. grape composition and wine quali…
2016
Regulation of grapevine water status is a common practice to manipulate grape composition and wine quality. In this investigation the effect of plant water status (two field water capacity-based irrigation levels, 75% and 100%, applied at single and combined vine developmental stages) and ripeness level (harvesting at different soluble solid levels) on grape composition and wine quality of Vitis vinifera L. cv. Shiraz/ Richter 99 was determined. Integrative effects of vine water relations and grape ripeness level, specifically in a Mediterranean high winter rainfall area, have not yet been investigated systematically. Source:sink mechanisms and dynamics and compositional and physical change…
Spatial Variation of Leaf Optical Properties in a Boreal Forest Is Influenced by Species and Light Environment
2017
Leaf Optical Properties (LOPs) convey information relating to temporally dynamic photosynthetic activity and biochemistry. LOPs are also sensitive to variability in anatomically related traits such as Specific Leaf Area (SLA), via the interplay of intra-leaf light scattering and absorption processes. Therefore, variability in such traits, which may demonstrate little plasticity over time, potentially disrupts remote sensing estimates of photosynthesis or biochemistry across space. To help to disentangle the various factors that contribute to the variability of LOPs, we defined baseline variation as variation in LOPs that occurs across space, but not time. Next we hypothesized that there wer…
Plant-Based Protein Hydrolysate Improves Salinity Tolerance in Hemp: Agronomical and Physiological Aspects
2021
Hemp (Cannabis sativa L.) is a multipurpose plant attracting increasing interest as a source for the production of natural fibers, paper, bio-building material and food. In this research we studied the agronomical performance of Cannabis sativa cv. Eletta Campana irrigated with saline water. Under those conditions, we tested the effect of protein hydrolysate (PH) biostimulant application in overcoming and/or balancing deleterious salinity effects. The results of the diverse treatments were also investigated at the physiological level, focusing on photosynthesis by means of a chlorophyll a fluorescence technique, which give an insight into the plant primary photochemical reactions. Four sali…
Responses of boreal carabid beetle assemblages (Coleoptera, Carabidae) to clear-cutting and top-soil preparation
2006
Today, forestry is the most important disturbance force in Fennoscandian boreal forests, having remarkably altered fauna and flora in this biome. However, since the late 1900s, forest-management practices have been modified to better consider biodiversity while harvesting timber. For example, green-tree retention, gap felling, and lighter top-soil preparation methods (harrowing) have been introduced, but little is known about the ecological effects of these changes. We sampled carabid beetles in seven clear-cut stands that were subsequently harrowed. We studied the effects of (1) clear-cut size by comparing carabid catches of small gaps (ca. 0.16 ha) with those of larger clear-cuts (ca. 2 h…
Are coastal communities able to pay for the protection of fish resources impacted by climate change?
2020
Abstract The purpose of this study is to examine inhabitants’ motivation and their willingness to pay to mitigate the impact of climate change on fish resources. Willingness to pay was tested empirically using survey data from 333 inhabitants of Sciacca, a fishing community in Sicily, Italy, which has the island’s second largest fishing fleet. People’s attitudes towards climate change, their degree of involvement in the issue, and their concerns about this phenomenon’s potential impact on the marine environment are the key factors affecting their willingness to pay. It was further found that respondents are willing to pay an average of €6.81 per month to support mitigation policies in the f…