5,313 research outputs found
Flower development and pollen vitality of moringa oleifera lam. Grown in a humid temperate climatic condition
Moringa oleifera is a tropical tree cultivated in many countries. This species has acquired a great importance in human nutrition and it was recently indicated as a “novel food” by the European Commission. Recently, moringa plants have been introduced in humid temperate climatic areas, among which Moreno (Buenos Aires Province-Argentina). In such area, the cultivation is possible for the production of leaves, but plants need protection during winter time in order to overcome damages due to low temperatures and hence to produce capsules and seeds. The main objective of this research was to study flower morphology and anatomy of M. oleifera, as well as microsporogenesis and viability of pollen grains of plants cultivated in Moreno in comparison with those produced in a humid sub-tropical climatic area of Argentina (San Miguel de Tucumán). Flowers grown in the temperate environment resulted similar for morphological parameters to those observed in the sub-tropical environment. Nevertheless, pollen grain fertility depended directly on air temperature and it was negatively affected by the lower temperatures registered in the temperate site. According to the observed results, pollen viability increases with mean monthly temperatures above 16°C.Fil: Radice, Silvia. Universidad de Moron. Facultad de Agronomia y Ciencias Agroalimentarias. Laboratorio de Investigaciones En FisiologĂa Vegetal; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Giordani, Edgardo. UniversitĂ degli Studi di Firenze; Itali
Decision Makers Facing Uncertainty: Theory versus Evidence
We consider three competing normative theories of how to make choices when facing uncertainty: subjective expected utility, maximin utility and minimax regret. In simple decision problems, we compare how decision makers under each of these theories value safe options, freedom of choice and information. We then use these models to predict answers to questions in the European Values Survey and use these predictions via a latent class analysis to estimate the distribution of these behaviors across Europe. We find a larger proportion of Bayesians in the Northern countries than in Southern countries. The opposite is true for maximin utility behavior. Only a few are consistent with minimax regret behavior
Project scheduling with generalized precedence relations: a new method to analyze criticalities and flexibilities
In this paper, we illustrate a new method to overcome the failures of the theory proposed by Elmaghraby and Kamburowski (1992) and De Reyck (1998) for the analysis of activity criticalities and flexibilities in non-preemptive project scheduling with generalized precedence relations under unlimited resources. These failures, discussed in detail in this paper, call for a new approach to study this problem. We provide new definitions of criticalities and consequently new tools for their identification within a more general framework without ambiguities
Scheduling activities in project network with feeding precedence relations: an earliest start forward recursion algorithm
In some production processes, the effort associated with a certain activity for its execution can vary over time. In this case, the amount of work per time unit devoted to each activity, so as its duration, is not univocally determined. This kind of problem can be represented by an activity project network with the so-called feeding precedence relations, and activity variable execution intensity. In this paper, we propose a forward recursion algorithm able to find the earliest start and finish times of each activity, in O(m log n) time, with n and m being the number of activities and the number of precedence relations, respectively. In particular, this requires the calculation of the (optimal) execution intensity profile, for each activity, that warrants the earliest start schedule and the minimum completion time of the project
Do longer sequences improve the accuracy of identification of forensically important Calliphoridae species?
Species identification is a crucial step in forensic entomology. In several cases the calculation of the larval age allows the estimation of the minimum Post-Mortem Interval (mPMI). A correct identification of the species is the first step for a correct mPMI estimation. To overcome the difficulties due to the morphological identification especially of the immature stages, a molecular approach can be applied. However, difficulties in separation of closely related species are still an unsolved problem. Sequences of 4 different genes (COI, ND5, EF-1\u3b1, PER) of 13 different fly species collected during forensic experiments (Calliphora vicina, Calliphora vomitoria, Lucilia sericata, Lucilia illustris, Lucilia caesar, Chrysomya albiceps, Phormia regina, Cynomya mortuorum, Sarcophaga sp., Hydrotaea sp., Fannia scalaris, Piophila sp., Megaselia scalaris) were evaluated for their capability to identify correctly the species. Three concatenated sequences were obtained combining the four genes in order to verify if longer sequences increase the probability of a correct identification. The obtained results showed that this rule does not work for the species L. caesar and L. illustris. Future works on other DNA regions are suggested to solve this taxonomic issue
On the concept of criticality on GPRs project network with variable activity durations
Temporal analysis of project networks has been widely studied in the literature; basically, it consists of determining the starting and finishing times of activities respecting a set of precedence constraints among them. The main output of the temporal analysis is twofold: on the one hand, it provides information on the minimum completion time of the project and, on the other hand, it determines which activity may be considered critical. Defining and determining activity criticalities on its own is a problem that has attracted the attention of many researchers over the last decades. In this paper, in an attempt to further pursue these studies, we focus on project scheduling with generalized precedence relationships where durations are not fixed in advance, but are variable within given ranges and have to be determined to minimize the makespan of the project. Analyzing activity criticalities for the same problem where activity durations are fixed has been tackled within the literature; what happens when durations are assumed variables, to the best of our knowledge, has not been investigated. We show that, in this scenario, the current knowledge on activity criticalities is no longer valid and we give new definitions of criticality together with the rules for its identification. An extensive experimental campaign on benchmark instances is presented to show that our findings are meaningful for quantitative project management
In vitro and in vivo biocompatibility of boron/nitrogen co-doped carbon nano-onions
Boron/nitrogen, co-doped, carbon nano-onions (BN-CNOs) have recently shown great promise as catalysts for the oxygen reduction reaction, due to the improved electronic properties imparted by the dopant atoms; however, the interactions of BN-CNOs with biological systems have not yet been explored. In this study, we examined the toxicological profiles of BN-CNOs and oxidized BN-CNOs (oxi-BN-CNOs) in vitro in both healthy and cancer cell lines, as well as on the embryonic stages of zebrafish (Danio rerio) in vivo. The cell viabilities of both cell lines cells were not affected after treatment with different concentrations of both doped CNO derivatives. On the other hand, the analysis of BN-CNOs and oxidized BN-CNO interactions with zebrafish embryos did not report any kind of perturbations, in agreement with the in vitro results. Our results show that both doped CNO derivatives possess a high biocompatibility and biosafety in cells and more complex systems. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Herpes zoster vaccination in the elderly subjects: improving awareness and uptake
Armando Stefanati, Nicoletta Valente, Silvia Lupi, Sara Previato, Matilde Giordani, Giovanni Gabutti Department of Medical Sciences, University of Ferrara, Ferrara, Italy Abstract: Herpes zoster (HZ) is a common disease in adults and older subjects solely related to the reactivation of latent varicella zoster virus in ganglia. The incidence of the disease increases with aging and the decline of varicella zoster virus-specific cell-mediated immunity. HZ has a significant impact on the quality of life of subjects during the acute phase. Besides, pain can persist even for a long time becoming chronic. The chronic pain following HZ is called postherpetic neuralgia, and it is a debilitating long-lasting condition, characterized by metameric pain, allodynia, and hyperalgesia. Therapeutic options against HZ and postherpetic neuralgia are often suboptimal and the impact of the disease and its complications on daily living activities is significant, especially in older subjects. Nowadays, a preventive approach to the disease is possible; as a matter of fact, a high-antigen content live vaccine is available. This vaccine has a good profile in terms of immunogenicity, efficacy, effectiveness, and safety and its use may prevent both HZ and postherpetic neuralgia. Nevertheless, the evaluation of the issues raised in countries that introduced this immunization show that both provider and patient barriers could have prevented a more robust uptake of HZ vaccination. In the USA, HZ immunization storage was expensive, reimbursement was cumbersome, and supply shortages may have limited promotion by the interests of the manufacturer and provider. The doctors did not actively recommend HZ vaccination; on the other hand, subjects were mostly unaware of the HZ vaccine. Several demographic factors, including sex and educational level, could have negatively affected the coverage rates; besides, the clinicians who treat adults focus less on vaccination than those taking care of children. On the other hand, when health care professionals undertook every effort to maximize the uptake of the shingles vaccine (eg, in the UK), the vaccine coverage rate increased very quickly. Keywords: herpes zoster, postherpetic neuralgia, vaccin
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