Pezzi G.,University of Bologna |
Maresi G.,Center for Technology Transfer |
Conedera M.,Swiss Federal Institute of forest |
Ferrari C.,University of Bologna
Landscape Ecology | Year: 2011
Chestnut stands (orchards and coppices) are among the most typical elements of the southern European mountain landscape and a protected habitat (9260 Castanea sativa woods) according to the European Union (Directive 92/43/EEC). As an anthropogenic landscape, they require specific measures to address preservation or to guide their evolutionary trend. In the Northern Apennines, a landscape multiscalar-multitemporal approach was adopted to highlight factors that have acted on the evolution of this habitat and which still might affect either its preservation or its evolutionary dynamics. Using a diachronic GIS-approach, we analyzed old cadastral maps (drawn up 200 years ago), and aerial photographs. Both the present distribution pattern of the woody species and the incidence of important chestnut diseases were also surveyed. The factors explaining the current extent and species composition of the local chestnut forests confirm their status as an anthropogenic habitat. The present landscape distribution of chestnut woods is heavily linked to past human settlements. Chestnut blight and ink disease are more an indirect reason for past felling activities than an actual direct cause of damage to trees, because of the hypovirulence spread and the limited incidence of the ink disease. Vegetation dynamics of abandoned chestnut forests evolved only partly towards deciduous Beech and Hop Hornbeam stands, thus suggesting both the possibility of a recovery of this cultivation and the need for new criteria for its management. © 2011 Springer Science+Business Media B.V.
News Article | December 6, 2016
The blood-brain barrier is a network of specialized cells that surrounds the arteries and veins within the brain. It forms a unique gateway that both provides brain cells with the nutrients they require and protects them from potentially harmful compounds. An interdisciplinary team of researchers from the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) headed by Gordon A. Cain University Professor John Wikswo report that they have developed a microfluidic device that overcomes the limitations of previous models of this key system and have used it to study brain inflammation, dubbed the "silent killer" because it doesn't cause pain but contributes to neurodegenerative conditions such as Alzheimer's and Parkinson's diseases. Recent research also suggests that it may underlie a wider range of problems from impaired cognition to depression and even schizophrenia. The project is part of a $70 million "Tissue Chip for Drug Testing Program" funded by the National Institutes of Health's National Center for Advancing Translational Sciences. Its purpose is to develop human organ-on-a-chip technology in order to assess the safety and efficacy of new drugs in a faster, cheaper, more effective and more reliable fashion. The importance of understanding how the blood-brain barrier works has increased in recent years as medical researchers have found that this critical structure is implicated in a widening range of brain disorders, extending from stroke to Alzheimer's and Parkinson's disease to blunt force trauma and brain inflammation. Despite its importance, scientists have had considerable difficulty creating faithful laboratory models of the complex biological system that protects the brain. Previous models have either been static and so have not reproduced critical blood flow effects or they have not supported all the cell types found in human blood-brain barriers. The new device, which the researchers call a NeuroVascular Unit (NVU) on a chip, overcomes these problems. It consists of a small cavity that is one-fifth of an inch long, one-tenth of an inch wide and three-hundredths of an inch thick - giving it a total volume of about one-millionth of a human brain. The cavity is divided by a thin, porous membrane into an upper chamber that acts as the brain side of the barrier and a lower chamber that acts as the blood or vascular side. Both chambers are connected to separate microchannels hooked to micropumps that allow them to be independently perfused and sampled. To create an artificial blood-brain barrier, the researchers first flip the device over so the vascular chamber is on top and inject specialized human endothelial cells. They found that if they maintain a steady fluid flow through the chamber during this period, the endothelial cells, which left to themselves form shapeless blobs, consistently orient themselves parallel to the direction of flow. This orientation, which is a characteristic of the endothelial cells in human blood-brain barrier, has been lacking in many previous models. After a day or two, when the endothelial cells have attached themselves to the membrane, the researchers flip the device and inject the two other human cell types that form the barrier -- star-shaped astrocytes and pericytes that wrap around endothelial cells -- as well as excitatory neurons that may regulate the barrier. These all go into the brain chamber that is now on top. The porous membrane allows the new cells to make physical and chemical contact with the endothelial cells just as they do in the brain. The researchers were able to purchase the human endothelial cells, astrocytes and pericytes that they need from commercial sources. For the excitatory neurons required, they turned to Vanderbilt University Medical Center collaborators M. Diana Neely, research associate professor of pediatrics, and Aaron Bowman, associate professor of pediatrics, neurology and biochemistry. Starting with human induced pluripotent stem cells that are generated directly from adult cells they were able to produce the specialized neurons that the project needed. "This is one of the most exciting projects I'm involved with," said Neely. "Although it's still in its infancy, it has tremendous potential." According to Bowman, one potential application is to develop tissue chips that contain cells from individual patients, making it possible to predict their personal reactions to different drugs. "Once we had successfully created the artificial barrier, we subjected it to a series of basic tests and it passed them all with flying colors. This gives us the confidence to state that we have developed a fully functional model of the human blood-brain barrier," said VIIBRE staff scientist Jacquelyn Brown, who is first author of the paper "Recreating blood-brain barrier physiology and structure on chip: A novel neurovascular microfluidic bioreactor" that described this achievement in the journal Biomicrofluidics. "The NVU has reached the point where we can begin using it to test different drugs and compounds," observed team member Donna Webb, associate professor of biological sciences who is interested in studying how different substances affect synapses -- the junctions between neurons. "There is an urgent need for us to understand how various substances affect cognitive processes. When we do, we will be in for a number of surprises! Providing the first continuous picture of inflammation response Already, the VIBRE team has used the NVU to overcome a basic limitation of existing studies of brain inflammation, which have only produced snapshots of the process at various stages. Because the NVU can be continuously monitored, it has provided the first dynamic view of how the brain and blood-brain barrier respond to systemic inflammation. These results are summarized in a paper titled "Metabolic consequences of inflammatory disruption of the blood-brain barrier in an organ-on-chip model of the human neurovascular unit" accepted for publication in the Journal of Neuroinflammation. The scientists exposed the NVU to two different compounds known to induce brain inflammation: a large molecule found on the surface of certain bacteria called lipopolysaccharide and a "cocktail" of small proteins called cytokines that play an important role in immune response to inflammation. "One of our biggest surprises was the discovery that a critical component in the blood-brain barrier's response to these compounds was to begin increasing protein synthesis," said Brown. "Next will be to find out which proteins it is making and what they do." The researchers also found that the blood vessels in the barrier respond to inflammation by pumping up their metabolic rate while the metabolism of the brain cells slows down. According to Brown, "It might be that the vasculature is trying to respond while the brain is trying to protect itself." The technology underlying the NVU has been patented and is available for commercialization. Interested parties should contact Ashok Choudhury or Masood Machingal at the Vanderbilt Center for Technology Transfer and Commercialization. Funding for the research was provided by National Institute of Environmental Health Sciences award R1 ES016931, National Institutes of Health grant DK50435 and National Center for Advancing Translational Sciences award 5UH3TR000491-04.
News Article | February 27, 2017
Wolbachia is the most successful parasite the world has ever known. You've never heard of it because it only infects bugs: millions upon millions of species of insects, spiders, centipedes and other arthropods all around the globe. The secret to the over-achieving bacterium's success is its ability to hijack its hosts' reproduction. Biologists have known that Wolbachia have had this power for more than 40 years but only now have teams of biologists from Vanderbilt and Yale Universities identified the specific genes that confer this remarkable capability. The two universities have applied for a patent on the potential use of these genes to genetically engineer either the bacterial parasite or the insects themselves to produce more effective methods for controlling the spread of insect-borne diseases like dengue and Zika and for reducing the ravages of agricultural pests. This achievement is described in the journal Nature in a paper titled "Prophage WO Genes Recapitulate and Enhance Wolbachia-induced Cytoplasmic Incompatibility" and in a companion article titled "A Wolbachia deubiquitylating enzyme induces cytoplasmic incompatibility" in Nature Microbiology published online on Feb. 27. "We've known for decades that one of the secrets to Wolbachia's success is that it interferes with host reproduction in order to spread itself through females. But how the bacterium did it was a major mystery for the field," said Associate Professor of Biological Sciences Seth Bordenstein, who headed the Vanderbilt contingent. "Now we know the genes that give it this capability." Wolbachia commonly manipulates its hosts' reproduction by a process called "cytoplasmic incompatibility" or CI. This makes the sperm of infected males lethal to the eggs of uninfected females. The researchers have identified a single pair of Wolbachia genes that produce this effect only when working together. When an infected male mates with an uninfected female, few if any of the eggs hatch. However, when an infected male mates with an infected female or when an uninfected male mates with an infected female, they produce the same number of offspring as when uninfected males and females mate. This maximizes the number of infected females produced in each generation, which benefits Wolbachia because it is only passed down through the maternal line. "This is an extremely effective strategy. Under ideal conditions it allows Wolbachia to infect an entire host population within a few generations or years," said Bordenstein. For a number of years, scientists have been looking for ways to use this natural bacterium to control mosquitoes that spread human diseases, and they have recently had some notable, early successes. Wolbachia is not normally found in Aedes aegypti, the mosquito that spreads dengue, Zika and chikungunya viruses. Ten years ago, however, a team of Australian scientists discovered that when Wolbachia is introduced into Aedes, it prevents these disease viruses from growing. That led to the creation of an international, non-profit collaboration called "Eliminate Dengue." The results have been extremely promising, so the groups are conducting field studies around the world to determine the most effective way to use Wolbachia to control Zika and dengue, which is considered the most important and most rapidly spreading mosquito-borne viral disease in the world. Other initiatives such as "MosquitoMate" in Kentucky are also using this approach to suppress the size of mosquito populations by releasing infected male mosquitoes which sterilize the uninfected females in the wild though CI. "There are two basic approaches for using Wolbachia to eliminate or curb the spread of a viruses like dengue and Zika," said Bordenstein. The stable approach, called population replacement, is to introduce both males and females infected with Wolbachia so they spread the bacteria on their own until they eventually replace the resident population. As they spread, the risk of dengue and Zika transmission drops because Wolbachia prevents these disease viruses from replicating. The second approach, called population suppression, is to introduce copious numbers of infected males. Because the uninfected females that mate with infected males fail to reproduce, this reduces the size of the target population of either disease-carrying insects or agricultural pests. The first approach is slow but steady and should eventually lead to the reduction or virtual elimination of disease transmission. The second approach is faster but the insect population can rebound so it must be administered repeatedly. The Vanderbilt researchers found that using genetic engineering to insert the Wolbachia CI genes into infected insects can strengthen the incompatibility effect and so significantly decrease the hatch rate of uninfected females who mate with infected males. As a result, it may increase the rate at which the bacterium spreads. This result raises two possibilities, which are the subject of the patent application: One is to directly transform strains of Wolbachia by inserting more copies of the CI genes. When used for population replacement, insects infected with this "super-Wolbachia" should spread more rapidly and could be more effective when used for population replacement or suppression. The other is to insert the CI genes into the insect's genome so they can cause CI directly. This would make it possible to use this technique to suppress insect species that are resistant to Wolbachia infection. Bordenstein and his colleagues have been hunting for the CI genes for nearly two decades and tracked them down by sequencing and comparing Wolbachia genomes from strains that cause and do not cause CI. They then used the process of elimination to track down the responsible genes. They discovered two genes that appeared promising. However, when the researchers inserted each of these genes into the genome of fruit flies, it was a complete bust. Neither of them affected the flies' reproduction: Their eggs hatched normally. "When we tried them together, however, it blew the roof off," said Bordenstein. "We were able to genetically reproduce and enhance the CI effect in Drosophila." According to the biologists, the origin of the CI genes remains a complete mystery. They are located in a portion of the Wolbachia genome called the eukaryotic association module, which contains genes that the bacterium appears to use to interact with its host. Other than that, the researchers have no idea where they come from.The researchers' next step is to search for the genes in infected females that counteract CI, which rescue their eggs and allow them to hatch normally. Co-authors of the Nature paper include: former doctoral students Jason Metcalf, Daniel LePage, and Lisa Funkhouser-Jones, current doctoral students Jessamyn Perlmutter and Dylan Shrophsire, Senior Research Associate Sarah Bordenstein, Research Assistant Jungmin On, Vanderbilt undergraduate Emily Layton, and John Beckmann, postdoctoral associate at the Yale School of Medicine. The research was supported by National Institutes of Health grants R21 HD086833, 5T32GM008554, T32GM07347, AI081322, National Science Foundation grants IOS 1456778 and DEB-1501398 and the Vanderbilt Cell Imaging Shared Resource. For licensing information go to Vanderbilt's Center for Technology Transfer & Commercialization.
News Article | February 22, 2017
The human heart beats more than 2.5 billion times in an average lifetime. Now scientists at Vanderbilt University have created a three-dimensional organ-on-a-chip that can mimic the heart's amazing biomechanical properties. "We created the I-Wire Heart-on-a-Chip so that we can understand why cardiac cells behave the way they do by asking the cells questions, instead of just watching them," said Gordon A. Cain University Professor John Wikswo, who heads up the project. "We believe it could prove invaluable in studying cardiac diseases, drug screening and drug development, and, in the future, in personalized medicine by identifying the cells taken from patients that can be used to patch damaged hearts effectively." The device and the results of initial experiments demonstrating that it faithfully reproduces the response of cardiac cells to two different drugs that affect heart function in humans are described in an article published last month in the journal Acta Biomaterialia. A companion article in the same issue presents a biomechanical analysis of the I-Wire platform that can be used for characterizing biomaterials for cardiac regenerative medicine. The unique aspect of the new device, which represents about two millionths of a human heart, is that it controls the mechanical force applied to cardiac cells. This allows the researchers to reproduce the mechanical conditions of the living heart, which is continually stretching and contracting, in addition to its electrical and biochemical environment. "Heart tissue, along with muscle, skeletal and vascular tissue, represents a special class of mechanically active biomaterials," said Wikswo. "Mechanical activity is an intrinsic property of these tissues so you can't fully understand how they function and how they fail without taking this factor into account." "Currently, we don't have many models for studying how the heart responds to stress. Without them, it is very difficult to develop new drugs that specifically address what goes wrong in these conditions," commented Charles Hong, associate professor of cardiovascular medicine at Vanderbilt's School of Medicine, who didn't participate in the research but is familiar with it. "This provides us with a really amazing model for studying how hearts fail." The I-Wire device consists of a thin thread of human cardiac cells 0.014 inches thick (about the size of 20-pound monofilament fishing line) stretched between two perpendicular wire anchors. The amount of tension on the fiber can be varied by moving the anchors in and out, and the tension is measured with a flexible probe that pushes against the side of the fiber. The fiber is supported by wires and a frame in an optically clear well that is filled with liquid medium like that which surrounds cardiac cells in the body. The apparatus is mounted on the stage of a powerful optical microscope that records the fiber's physical changes. The microscope also acts as a spectroscope that can provide information about the chemical changes taking place in the fiber. A floating microelectrode also measures the cells' electrical activity. According to the researchers, the I-Wire system can be used to characterize how cardiac cells respond to electrical stimulation and mechanical loads and can be implemented at low cost, small size and low fluid volumes, which make it suitable for screening drugs and toxins. Because of its potential applications, Vanderbilt University has patented the device. Unlike other heart-on-a-chip designs, I-Wire allows the researchers to grow cardiac cells under controlled, time-varying tension similar to what they experience in living hearts. As a consequence, the heart cells in the fiber align themselves in alternating dark and light bands, called sarcomeres, which are characteristic of human muscle tissue. The cardiac cells in most other heart-on-a-chip designs do not exhibit this natural organization. In addition, the researchers have determined that their heart-on-a-chip obeys the Frank-Starling law of the heart. The law, which was discovered by two physiologists in 1918, describes the relationship between the volume of blood filling the heart and the force with which cardiac cells contract. The I-Wire is one of the first heart-on-a-chip devices to do so. To demonstrate the I-Wire's value in determining the effects that different drugs have on the heart, the scientists tested its response with two drugs known to affect heart function in humans: isoproterenol and blebbistatin. Isoproterenol is a medication used to treat bradycardia (slow heart rate) and heart block (obstruction of the heart's natural pacemaker). Blebbistatin inhibits contractions in all types of muscle tissue, including the heart. According to Veniamin Sidorov, the research assistant professor at the Vanderbilt Institute for Integrative Biosystems Research and Education (VIIBRE) who led its development, the device faithfully reproduces the response of cardiac cells in a living heart. "Cardiac tissue has two basic elements: an active, contractile element and a passive, elastic element," said Sidorov. "By separating these two elements with blebbistatin, we successfully characterized the elasticity of the artificial tissue. By exposing it to isoproterenol, we tested its response to adrenergic stimulation, which is one of the main systems responsible for regulation of heart contractions. We found that the relationship between these two elements in the cardiac fiber is consistent with that seen in natural tissue. This confirms that our heart-on-a-chip model provides us with a new way to study the elastic response of cardiac muscle, which is extremely complicated and is implicated in heart failure, hypertension, cardiac hypertrophy and cardiomyopathy." Other members of the VIIBRE research team are Professor of Pathology, Microbiology and Immunology Jeffrey Davidson, former Assistant Professor of Medicine Chee Lim (now at NIH), Assistant Professor of Biostatistics Matthew Shotwell and Associate Professor of Biomedical Engineering David Merryman, Senior R&D Engineer Philip Samson, postdoctoral fellow Tatiana Sidorova and doctoral student Alison Schroer. The I-Wire technology has been patented and is available for licensing. Interested parties should contact Ashok Choudhury or Masood Machingal at the Vanderbilt Center for Technology Transfer and Commercialization. The research was supported by National Institutes of Health grants 1R01118392-01, R01 HL118392, R01 HL095813 and 5R01-AR056138; National Science Foundation grants 1055384 and DGE-0909667; Defense Threat Reduction Agency grant CBMXCEL-XL1-2-001; American Heart Association grant 15PRE25710333; and by the Department of Veterans Affairs.
Beltrami M.E.,Center for Technology Transfer |
Ciutti F.,Center for Technology Transfer |
Cappelletti C.,Center for Technology Transfer |
Losch B.,Laboratorio Biologico |
And 2 more authors.
Hydrobiologia | Year: 2012
The Water Framework Directive 2000/60/EC (WFD) requires the analysis of biological elements of aquatic ecosystems to assess water quality. Diatoms are the component of the periphyton most commonly used to classify lotic environments. Within the context of the WFD the concept of 'reference conditions' was introduced and biological quality of watercourses is expressed as Ecological Quality Ratio (EQR). This study was carried out in Alto Adige/Südtirol (Province of Bolzano-Bozen, northern Italy), belonging to the Alpine eco-region, and to the hydro-ecoregion Inner Alps. During 2006-2009, epilithic diatoms were sampled from monitoring and reference sites of seven stream types. Diatom assemblages were analysed with TWINSPAN and CCA analyses to investigate species association and distribution in relation to stream characteristics. Altitude and geology resulted to be the most important factors influencing diatom assemblage composition, and were used to describe new stream types. Indicator species analysis was used to characterize reference assemblages. The biological quality of watercourses was assessed using different diatom indices: Specific Pollution sensitivity Index (IPS), Eutrophication and Pollution Index with Diatoms (EPI-D), Trophic Index (TI). We tested also the Intercalibration Common Metric index (ICM). © 2012 Springer Science+Business Media B.V.
Piskur B.,Slovenian Forestry Institute |
Pavlic D.,University of Pretoria |
Slippers B.,University of Pretoria |
Ogris N.,Slovenian Forestry Institute |
And 3 more authors.
European Journal of Forest Research | Year: 2011
Unusual and extensive dieback of European hop hornbeam (Ostrya carpinifolia) has been observed in western Slovenia and northern Italy in recent years, when extreme drought and higher temperatures were recorded. A preliminary study identified Botryosphaeria dothidea as a potential causative agent of the dieback. Further characterization of intra- and interspecies diversity of Botryosphaeriaceae collected from O. carpinifolia and other tree species in the affected area was achieved based on anamorph morphology, sequence data from the ITS rDNA and EF1-α, PCR-RFLP analysis and AFLP profiles. The majority of the isolates analyzed were identified as B. dothidea, and in vitro pathogenicity tests re-confirmed the fungus to be an important cause of the disease. Insight into the B. dothidea population, diversity based on AFLP markers indicates that the dieback observed in O. carpinifolia is probably associated with a heterogenous population of B. dothidea, which emerged from a latent state in response to changed climate conditions. Isolates with Dothiorella-like conidia were also identified during the survey, but these were collected more rarely and appear to represent undescribed species. Isolates from Dothiorella genus expressed low pathogenicity in pathogenicity tests and proved no impact on the pathogenic ability of B. dothidea. © 2010 Springer-Verlag.
Pisetta M.,Center for Technology Transfer |
Montecchio L.,University of Padua |
Longa C.M.O.,Research and Innovation Center |
Salvadori C.,Center for Technology Transfer |
And 2 more authors.
Forest Ecology and Management | Year: 2012
Decline of green alder (Alnus viridis spp. viridis [Chaix] D.C.) has been reported since the 1990s in the Alps. In recent years, this disease has spread all over the Alps and it is now recorded over all Italian alpine regions, with several secondary green alder stands heavily affected. Old damaged stands show dramatic changes both in tree species composition and coverage. Investigations were carried out in Trentino province (northern Italy) to describe the pathological and ecological aspects of this phenomenon.Various fungi and insects were detected on declining trees, but no single agent appeared to be a primary cause; the most common coloniser of declining stems, Cryptodiaporthe oxystoma (Rehm) Urb., had an endophytic behaviour in green healthy tissues but failed to produce symptoms in artificial inoculations. There was a negative relation between altitude and alder decline. Furthermore, reduction in snow cover and trends of increase in winter temperature are possible influencing factors.The spread of the syndrome may be related to climate change, reducing green alder vigour and allowing opportunistic parasites to cause host decline. The disappearance of green alder stands will likely affect soil protection, biodiversity and stand evolution in treeline forests of the Alps. More research is needed to define future management options. © 2012 Elsevier B.V.
Ioriatti C.,Center for Technology Transfer |
Lucchi A.,University of Pisa
Journal of Chemical Ecology | Year: 2016
- This review summarizes work done in Italy in taking semiochemical-based management of orchard and vineyard pests from the research and development stage to successful commercial deployment. Mating disruption (MD) of codling moth Cydia pomonella (CM) was originally introduced into the Trentino-South Tyrol areas to address the development of CM resistance to insecticides, particularly insect growth regulators (IGRs), and to mitigate the conflict at the rural/urban interface related to the extensive use of insecticides. Although the mountainous terrain of the area was not optimal for the efficacy of MD, commitment and determination led to the rapid adoption of MD technology throughout the region. Grower cooperatives and their field consultants were strongly influential in convincing growers to accept MD technology. Public research institutions conducted extensive research and education, and provided credible assessments of various MD technologies. By 2016, the deployment of MD in effective area-wide strategies in apple (22,100 ha) and grapes (10,450 ha), has resulted in better control of tortricid moth pests and a substantial decrease in insecticide use. Collaboration between the research community and the pheromone industry has resulted in the development of increasingly effective single-species dispensers, as well as multi-species dispensers for the control of both target and secondary pests. Over the last 20 years, hand-applied reservoir dispensers have shown excellent efficacy in both apple and grapes. Recently, aerosol dispensing systems have been shown to be effective in apple orchards. Further research is needed on the efficacy of aerosols in vineyards before the technology can be widely adopted. The successful implementation of MD in apple and grape production in Trentino-South Tyrol is expediting adoption of the technology in other Italian fruit production regions. © 2016 Springer Science+Business Media New York
Zorer R.,Geographic Information System and Remote Sensing Unit |
Rocchini D.,Geographic Information System and Remote Sensing Unit |
Metz M.,Geographic Information System and Remote Sensing Unit |
Delucchi L.,Geographic Information System and Remote Sensing Unit |
And 3 more authors.
IEEE Transactions on Geoscience and Remote Sensing | Year: 2013
Heat requirements for grapevine varieties have been widely used to characterize potential growing regions for viticulture. One of the most common landscape classifications is based on the Winkler Index (WI) values, defined as the total summation of daily average air temperature above 10°C from April 1 to October 31 in the Northern Hemisphere. Mapping WI is commonly performed by spatial interpolation of temperature data collected with weather station (WS) networks. However, in complex terrain such as the European Alps, these are usually irregularly and sparsely distributed or unavailable. This renders traditional geospatial interpolation approaches unreliable. As an alternative, thermal remote sensing data, which are intrinsically spatialized, can be used. The aims of this paper are the following: 1) to provide time series of WI-value maps from 2003 to 2010, by means of the Moderate-resolution Imaging Spectroradiometer (MODIS) land surface temperature (MOD11A1 and MYD11A1) daily data and 2) to calibrate them using ground truth data, collected by two WS networks, 3) leading to a classification of the study area into WI regions. WI values from WS data and from MODIS data exhibit a strong linear regression, close to the 1 : 1 prediction with an offset of 42.02 and a slope of 0.90. These coefficients have been used to calibrate the original map, before the following classification. The study area was found to have growing degree days that correspond to four Winkler Regions. The use of MODIS data represents a robust and straightforward method for selectively detecting areas suitable for grapevine varieties, particularly in regions with sparsely distributed WSs. © 1980-2012 IEEE.
Maresi G.,Center for Technology Transfer |
Oliveira Longa C.M.,Research and Innovation Center |
Turchetti T.,CNR Institute of Neuroscience
IForest | Year: 2013
The quality and quantity of nut production are fundamental to the economic viability of chestnut cultivation, yet recent reports indicate that severe damage due to moulds represents a significant problem for growers. We carried out an investigation of the agents of chestnut rot and internal fruit damage in three orchards in Italy. Black and brown rot, as well as insect damage, were found in all the areas examined. Brown rot appeared to be the main cause of damage, affecting 8% to 49% and 2% to 24% of nuts collected from the ground and from burrs, respectively. With respect to morphology and DNA sequencing analyses, fungal isolates obtained from brown rot were homologous with Gnomoniopsis sp. obtained from Dryocosmus kuriphilus (Yasumatsu) galls and with Gnomoniopsis castanea and Gnomoniopsis smithogilvyi described on chestnut in Italy and Australia, respectively. The same fungus was also isolated from the bark of one- and two-years-old healthy shoots at each site, supporting the endophytic behaviour of this rot agent. Brown rot symptoms on nuts associated with Gnomoniopsis sp. corresponded with those previously described by several authors and referred to as Phoma or Phomopsis endogena, suggesting a relationship between these fungi and Gnomoniopsis sp. It is to notice that the escalation of brown rot damage in Italy followed several periods of drought and probably the recent invasion of D. kuriphilus, both stress factors for chestnut trees. © iForest - Biogeosciences and Forestry.