Climate Events and Insurance Demand - The effect of potentially catastrophic events on insurance demand in Italy

Climate extreme events are constantly increasing. What is the effect of these potentially catastrophic events on insurance demand in Italy, with particular reference to the economic activities? Extreme precipitation events over most of the midlatitude land masses and over wet tropical regions will very likely become more intense and more frequent by the end of this century, as global mean surface temperature increases. If we look to Italy, examination of the precipitation time series shows a sensitive and highly significant decrease in the total number of precipitation events in Italy, with a trend of events intense dissimilar as regards to low and high intensity, with a decline of firsts and an increase of seconds. The risk related to hydrological natural disasters is in Italy one of the most important problem for both damage and number of victims. How evolves the ability to pay for damages, with a view to safeguarding work and economic activities, and employment protection?Comment: Chiara Daniela Pronzato (Research coordinator), Isabella Pecetto (Research collaborator

Rainfall variability, plant functional traits and productivity in grasslands

Grasslands are important ecosystems worldwide, and their diversity and productivity is strongly linked to rainfall patterns and soil nutrient availability. Changes in water and soil nutrients, associated with climate change and management regimes, are likely to have strong consequences for grasslands in the future. While the relationship between rainfall, nutrients, and grassland productivity has been well described, a mechanistic explanation as to why some grassland communities are more sensitive than others remains elusive. Plant functional traits are useful to address this issue on a global scale, as they represent life history strategies and are universal across all plant taxa. Such traits often represent the inevitable trade-off between rapidly acquiring resources and the increasing rate of tissue turnover. Such faster-growing species, referred to as acquisitive species, can be compared with conservative species, which are slower growing and have low rates of tissue turnover, along the resource-use axis. To address how grasslands may respond to future changes in rainfall and fertilisation, I conducted a series of experiments using grasses and grassland ecosystems to study how traits may be used to understand variation in sensitivity across species and communities. My research illustrates that the abundance of acquisitive and conservative plant species in a community can result in high levels of variation in productivity, a primary function of grasslands critical for pasture utilisation and carbon sequestration. I found that root traits of grasses were responsive to phosphorus fertilisation. As the primary organ for water uptake in plants, changes in root morphology associated with P availability may alter how grassland communities respond to changes in precipitation. In addition, I found grouping species based on their functional types was helpful in quantifying plant biomass in remote arid and semi-arid regions, where logistics of scientific investigation can be difficult. More specifically, I developed a set of allometric equations which use non-destructive proxies (plant cover and height) to estimate plant biomass. These estimates were improved by grouping species based on the functional type (i.e. rough morphological and life-history characteristics). Finally, I investigated how interspecific plant interactions (namely competition) may change under different timing and severity of droughts to identify key candidate grasses for multispecies pasture utilisation. Ultimately, this work contributes valuable information regarding the underlying mechanisms to varying sensitivity in productivity in grassland communities and individual grass species, which will be increasingly important to manage under future climatic scenarios

Immune cells and microbiota response to iron starvation

Metal ions are essential for life on Earth, mostly as crucial components of all living organisms; indeed, they are necessary for bioenergetics functions as crucial redox catalysts. Due to the essential role of iron in biological processes, body iron content is finely regulated and is the battlefield of a tug-of-war between the host and the microbiota.Iron availability in the intestinal lumen could prevent or promote intestinal dysbiosis, although current data do not provide a definitive response. Recent data demonstrated that nutritional derived polyphenols explicit their anti-inflammatory functions sequestrating iron from immune cells. Here, we discuss whether nutritional iron chelators could be able to change the gut microbiota composition and prevent the intestinal dysbiosis associated with intestinal chronic inflammatory syndromes.Iron is lost by cellular exfoliation and occasional bleeding; it is absorbed from nutritional components. Heme is the most important source of dietary iron, while non-heme iron can be absorbed only in the duodenum and the beginning of the jejunum in pH permissive (acid) conditions. Western diets often contain large quantities of foods characterized by a high heme-iron content like meat, fish, and poultry, and small quantities of non-heme-iron content like vegetables, fruits, and nuts. Furthermore, nutritional substances can affect iron absorption: ascorbic acid is an efficient enhancer of non-heme-iron absorption, vice versa, phytic acid is known to be among the major iron absorption inhibitors, and iron-chelating substances like quercetin inhibit its absorption, likely due to loss of chelated-iron solubility.Iron deficiency is the most common cause of anemia worldwide and one of the most common complications observed in inflammatory bowel disease (IBD) patients due to gastrointestinal hemorrhages. In IBD patients, the guidelines for the management of iron deficiency are not entirely satisfactory because following oral iron supplementation patients sometimes report worsening of the IBD symptoms (1). Interestingly, iron supplemented diets can also show protective effects in dextran sodium sulfate (DSS)-induced colitis models. Constante et al. demonstrated that iron formulation dramatically changed the outcome of the DSS-induced colitis, as oral supplementation with ferrous bisglycinate but not ferric ethylenediaminetetraacetic acid enhanced the beneficial action of probiotics (2)

Messages from the inside. The dynamic environment that favors intestinal homeostasis

An organism is defined as "an individual living thing capable of responding to stimuli, growing, reproducing, and maintaining homeostasis." Early during evolution multicellular organisms explored the advantages of a symbiotic life. Mammals harbor a complex aggregate of microorganisms (called microbiota) that includes bacteria, fungi, and archaea. Some of these bacteria have already defined beneficial roles for the human host that include the ability to break down nutrients that could not otherwise be digested, preventing the growth of harmful species, as well as the ability to produce vitamins or hormones. It is intuitive that along the evolutionary path several mechanisms favored bacteria that provided advantages to the host which, in return, avoided launching an aggressive immunological response against them. The intestinal immunological response does not ignore the lumenal content, on the contrary, immune surveillance is favored by continuous antigen sampling. Some intestinal epithelial cells (ECs) are crucial during the sampling process, others actively participate in the defense mechanism. In essence the epithelium acts as a traffic light, communicating to the inside world whether conditions are safe or dangerous, and thus influencing immunological response. In this review we will discuss the dynamic factors that act on the intestinal ECs and how they directly or indirectly influence immune cells during states of health and disease. © 2013 Eri and Chieppa

Photosynthetic responses to climate warming differ among forest plant species in a temperate--subtropical forest ecotone

Temperatures in Florida are expected to increase ~5°C by 2100. North Florida will shift from a temperate/subtropical climate to a tropical climate within 30 years which could alter the forest composition and productivity. We conducted a field experiment using warming chambers to determine how warming impacts the physiological performance of four species in North Florida: Serenoa repens (saw palmetto), Andropogon glomeratus (bushy bluestem), Pinus palustris (longleaf pine), and Quercus laevis (turkey oak). Over one year we measured rates of leaf net photosynthesis (A) and stomatal conductance to water vapor (gs) on seedlings of each species under ambient and warmed treatments. We hypothesized climate warming effects on leaf physiology would vary among species and with changes in soil moisture. We predicted species with tropical distributions and adaptations to high temperatures (palmetto and C4 grass) would increase photosynthesis with warming compared to species with temperate distributions (oak and pine), and across species, reductions in soil moisture would diminish the positive effects of warming on photosynthesis. We found photosynthesis increased with warming in S. repens and A. glomeratus, did not change with warming in Q. laevis, and decreased with warming in P. palustris. Photosynthetic responses to warming did not vary with soil moisture in both S. repens and A. glomeratus. However, warming reduced photosynthesis in Q. laevis and P. palustris when soil moisture was low. These results suggest climate warming might benefit grasses and palmetto at the expense of native tree species, foreshadowing a shift in forest structure, composition, and productivity

Plant Polyphenols-Biofortified Foods as a Novel Tool for the Prevention of Human Gut Diseases

Plant food biofortification is recently receiving remarkable attention, as it aims to increase the intake of minerals, vitamins, or antioxidants, crucial for their contribution to the general human health status and disease prevention. In this context, the study of the plant’s secondary metabolites, such as polyphenols, plays a pivotal role for the development of a new generation of plant crops, compensating, at least in part, the low nutritional quality of Western diets with a higher quality of dietary sources. Due to the prevalent immunomodulatory activity at the intestinal level, polyphenols represent a nutritionally relevant class of plant secondary metabolites. In this review, we focus on the antioxidant and anti-inflammatory properties of different classes of polyphenols with a specific attention to their potential in the prevention of intestinal pathological processes. We also discuss the latest biotechnology strategies and new advances of genomic techniques as a helpful tool for polyphenols biofortification and the development of novel, healthy dietary alternatives that can contribute to the prevention of inflammatory bowel diseases

Looking at flavonoid biodiversity in horticultural crops: A colored mine with nutritional benefits

Flavonoids represent a wide group of plant secondary metabolites implicated in many physiological roles, from the attraction of pollinators to the protection against biotic or abiotic stresses. Flavonoids are synthetized in a number of horticultural crops that are important components of our daily diet. In the last decades, the consumption of vegetables rich in antioxidants has been strongly promoted from the perspective of prevention/protection against chronic diseases. Therefore, due to their nutritional importance, several attempts have been made to enhance flavonoid levels in species of agronomic interest. In this review, we focus on the flavonoid biodiversity among the major horticultural species, which is responsible of differences among closely related species and influences the qualitative/quantitative composition. We also review the role of flavonoids in the nutritional quality of plant products, contributing to their organoleptic and nutritional properties, and the main strategies of biofortification to increase their content

Exploring patterns of thermal acclimation of leaf respiration in a marsh-mangrove ecotone

Vegetated coastal ecosystems (saltmarsh, mangroves) make a large contribution to global net primary productivity and C cycling despite covering a small proportion of the earth’s surface. Yet, our understanding of C cycling processes over space and time and in response to temperature remain limited for these ecosystems. At the global scale, respiration is the second largest flux of C (behind photosynthesis), and ~50% of respiration comes from leaves. Respiration is also a key parameter for global models that predict climate-carbon cycle interactions. But respiratory responses to temperature in marsh and mangrove species remain uncertain. Here, we repeatedly measured short-term temperature responses of leaf respiration in a C4 marsh grass species (Spartina alterniflora) and a C3 mangrove species (Avicennia germinans) growing under ambient temperatures and experimental warming at two sites in Florida. We tested whether marsh grasses and mangroves show similar acclimation of leaf respiration to seasonal temperature changes at sites differing in temperature seasonality, and whether acclimation is consistent between plants grown under ambient and warmed conditions

Intestinal epithelium and autophagy: Partners in gut homeostasis

One of the most significant challenges of cell biology is to understand how each type of cell copes with its specific workload without suffering damage. Among the most intriguing questions concerns intestinal epithelial cells in mammals; these cells act as a barrier between the internally protected region and the external environment that is exposed constantly to food and microbes. A major process involved in the processing of microbes is autophagy. In the intestine, through multiple, complex signaling pathways, autophagy including macroautophagy and xenophagy is pivotal in mounting appropriate intestinal immune responses and anti-microbial protection. Dysfunctional autophagy mechanism leads to chronic intestinal inflammation, such as inflammatory bowel disease (IBD). Studies involving a number of in vitro and in vivo mouse models in addition to human clinical studies have revealed a detailed role for autophagy in the generation of chronic intestinal inflammation. A number of genome-wide association studies identified roles for numerous autophagy genes in IBD, especially in Crohn's disease. In this review, we will explore in detail the latest research linking autophagy to intestinal homeostasis and how alterations in autophagy pathways lead to intestinal inflammation. © 2013 Randall-Demllo, Chieppa and Eri