Search results for "GRO"
showing 10 items of 31405 documents
Evaluation of some growth regulator effects on encapsulated in vitro-derived microcuttings of three Italian Ficus carica L. genotypes.
2017
In this study, the encapsulation technology based on the calcium alginate coating was applied to some Ficus carica L. genotypes. Uninodal microcuttings (3-4 mm long), excised from in vitro proliferating shoots of three Italian cultivars (‘Bifera’, ‘Palazzo’ and ‘Catalanisca’), were employed. The influence of three different plant growth regulators (PGRs): 6-benzylaminopurine (BAP), meta-topolin (MT) and zeatine (ZEA), added to the artificial endosperm, were evaluated. Particularly, the viability, regrowth and conversion parameters of the synthetic seeds were registered after 60 days from the sowing on a hormone-free medium. Results showed that the cultivars ‘Catalanisca’ and ‘Palazzo’ showe…
Developing an orientation and cutting point determination algorithm for a trout fish processing system using machine vision
2019
Abstract Fish processing in small and medium fish supplying centers requires an intelligent system to operate on different sizes. Therefore, an image processing algorithm was developed to extract the proper head and belly cutting points according to the trout dimensions. The algorithm detects the fish orientation and location of pectoral, anal, pelvic, and caudal fins. In this study, each of the trout images was divided into slices along its length in order to segment the fins and extract cutting points. The channel ‘B’ of RGB color space was considered in both initial segmentation and fin detection stages among the examined channels of RGB, HSV, and L*a*b* color spaces. The back-belly and …
Influence of dams on population persistence in Atlantic salmon (Salmo salar)
2016
Barriers to migration can negatively affect population persistence. To explore how dams can influence the viability of a diadromous fish, we developed an empirically based stochastic model to estimate per-capita population growth rate (r) and probability of population decline (Pr(r < 0)). Our simulations incorporated life-history parameters common for many populations of Atlantic salmon (Salmo salar L., 1758), particularly in the southern part of the species range. Additionally, we explored the influence of individuals that reproduce more than once, i.e., “kelts”, on r and Pr(r < 0). For the life-history scenarios examined here, dams are forecast to negatively affect persistence, eve…
Spatial reference points for groundfish
2016
Abstract According to density-dependent habitat selection theory, areas of high density can be indicative of high population productivity and have positive individual fitness consequences. Here, we explore six groundfish populations on the Scotian Shelf, Canada, where a decline in areas of high density beyond a certain threshold is associated with disproportionately large declines in Spawning Stock Biomass (SSB). This is evidenced by empirical, concave, positive relationships between high-density areas (HDAs) and SSB. We introduce a methodology to estimate the threshold below which SSB declines increasingly faster per unit of HDA decline. The spatial threshold among these six stocks was rem…
An Updated Checklist of the Sicilian Native Edible Plants: Preserving the Traditional Ecological Knowledge of Century-Old Agro-Pastoral Landscapes
2020
The traditional use of native wild food plants (NWFP) may represent a valuable supplementary food source for the present and future generations. In Sicily, the use of wild plants in the human diet dates back to very ancient times and still plays an important role in some rural communities. Moreover, in this regard, the natural and cultural inheritance of this island is wealthy and diversified for several reasons. First, Sicily hosts a rich vascular flora, with 3,000 native and 350 endemic plants. Second, due to its central position in the Mediterranean, the island has acted as a veritable melting pot for the ethnobotanical knowledge of the rural communities of the entire basin. We reviewed …
A preliminary approach for modelling the effects of cropping systems on the dynamics of broomrape ( Phelipanche ramosa) in interaction with the non-p…
2011
International audience; The current decrease in herbicide use may increase and diversify weed flora in crops as well as companion bioagressors spreading via weeds. Among these bioagressors is Phelipanche ramosa (L.) Pomel, a parastic plant which is very harmful on oilseed rape. The objective of the present work was to develop a new model (called PheraSys) of the effects of cropping systems on parasite dynamics, in interaction with non-parasitic weed hosts. The structure of this first model version was based on models developed for other parasitic plants and on FlorSys which quantifies the effects of cropping systems on non-parasitic weed flora. PheraSys was parametrized with preliminary val…
Demographic responses of a site-faithful and territorial predator to its fluctuating prey: long-tailed skuas and arctic lemmings.
2014
Summary1. Environmental variability, through interannual variation in food availability or climaticvariables, is usually detrimental to population growth. It can even select for constancy in keylife-history traits, though some exceptions are known. Changes in the level of environmentalvariability are therefore important to predict population growth or life-history evolution.Recently, several cyclic vole and lemming populations have shown large dynamical changesthat might affect the demography or life-histories of rodent predators.2. Skuas constitute an important case study among rodent predators, because of theirstrongly saturating breeding productivity (they lay only two eggs) and high deg…
Understanding insect foraging in complex habitats by comparing trophic levels: insights from specialist host-parasitoid-hyperparasitoid systems
2019
Insects typically forage in complex habitats in which their resources are surrounded by non-resources. For herbivores, pollinators, parasitoids, and higher level predators research has focused on how specific trophic levels filter and integrate information from cues in their habitat to locate resources. However, these insights frequently build specific theory per trophic level and seldom across trophic levels. Here, we synthesize advances in understanding of insect foraging behavior in complex habitats by comparing trophic levels in specialist host-parasitoid-hyperparasitoid systems. We argue that resources may become less apparent to foraging insects when they are member of higher trophic …
Grasslands provide diverse opportunities for bird species along an urban-rural gradient
2021
Urbanisation is a major cause of biodiversity loss but careful habitat management and provision of green space within cities can help to mitigate its negative effects. Grasslands occupy large surface areas and have many functions but only a few studies have begun to explore how birds exploit these habitats in urban contexts. We hypothesized that the value of grasslands for nesting and feeding birds is likely to depend both on landscape context, and on local characteristics (grassland size, use and vegetation structure). We surveyed local habitat characteristics, breeding bird presence, abundance and foraging activity in 47 grassland sites, distributed along an urban-rural gradient in two Fr…
Whistle variation in Mediterranean common bottlenose dolphin: The role of geographical, anthropogenic, social, and behavioral factors.
2020
Abstract The studies on the variation of acoustic communication in different species have provided insight that genetics, geographic isolation, and adaptation to ecological and social conditions play important roles in the variability of acoustic signals. The dolphin whistles are communication signals that can vary significantly among and within populations. Although it is known that they are influenced by different environmental and social variables, the factors influencing the variation between populations have received scant attention. In the present study, we investigated the factors associated with the acoustic variability in the whistles of common bottlenose dolphin (Tursiops truncatu…