Search results for " Reproduction"
showing 10 items of 282 documents
Flower and fruit structure of the endangered species Petagnaea gussonei (Sprengel) Rauschert (Saniculoideae, Apiaceae) and implications for its repro…
2015
Petagnaea gussonei (Apiaceae) is an endangered species endemic to the Nebrodi mountains (north-eastern Sicily). Although an increasing number of studies have been performed on this species, its reproductive biology remains poorly understood. The aim of this study was to investigate in detail the structure of the flower and the fruit of Petagnaea, and the possible implications for its breeding system and seed dispersal mechanism. Results from fieldwork, light microscopy and scanning electron microscopy suggest (1) the presence of protandrous hermaphrodite flowers; (2) geitonogamy, autogamy, and allogamy as breeding system mechanisms of P. gussonei, even if asexual reproduction is preferred b…
Growth and reproduction of the deep-water rose shrimp, Parapenaeus longirostris (Lucas, 1846) (Decapoda, Penaeidae), in the southern Tyrrhenian sea.
2014
From June 2006 to May 2007, monthly samples of Parapenaeus longirostris (Lucas, 1846) were collected on land from the landings of two different, although contiguous, fishing grounds exploited by the bottom trawl fisheries of the two fishing harbours of Terrasini and Porticello, located on the north-western coast of Sicily. Carapace length (CL) of the female and male deep-water rose shrimp in Terrasini ranged from 9 to 32 mm and 13 to 26 mm, respectively, whereas in Porticello the length ranged from 8 to 31 mm and 13 to 26 mm, respectively. The Von Bertalanffy Growth Function parameters for Terrasini females and males were CLoo = 38.5 mm, K = 0.65 year(-1) and CL infinity = 32.5 mm, K = 0.85…
Arbacia
2020
Arbacia is unique among shallow echinoid genus, not in line with the general rule that sea urchins should be either entirely tropical or entirely temperate, with limited overlap in the subtropics. Six extant Arbacia species have been described by Mortensen. The genus Arbacia has a Neotropical origin and four different fossil species have been described from the Late Miocene. Over the past century, Arbacia has been the subject of intense investigations into the cell biology, toxicology, biochemistry, and embryology. Recently, renewed interest in this genus arose from its phylogeny, ecology, and its resilience to ocean warming and acidification. According to several studies, impacts of ocean …
«Un vero e proprio film»: Longhi, Briganti e La Maniera italiana (1961)
2021
Il saggio propone un'analisi dettagliata del percorso editoriale del volume «La Maniera italiana» che Giuliano Briganti pubblica nel 1961 come primo volume di una collana di libri interamente illustrati a colore, redatti da Editori Riuniti insieme a Verlag der Kunst (Dresda, RDT). Grazie a inedite fonti d'archivio questo studio ricostruisce la storia di un singolare episodio di divulgazione storico-artistica che vede Roberto Longhi nella veste di direttore editoriale, affiancato dal critico d'arte Antonio Del Guercio in qualità di segretario redazionale. The essay offers a detailed analysis of Giuliano Briganti's book «La Maniera italiana», which was published in 1961 as the first volume of…
Psychological variables in medically assisted reproduction: a systematic review
2022
Introduction: The paths of medically assisted reproduction represent the most important scientific progress to cope with the inability to achieve spontaneous conception (SC) and to reach desired parenthood. Couples undergoing assisted reproductive technology (ART) and couples not facing ovulation induction and artificial fertilization show sufficient levels of well-being and psychological adjustment. However, in some cases couples undergoing ART show lower perceived quality of life than couples with SC. Our aim is to investigate the main psychological variables involved in the special risk condition of medically assisted reproduction and how they could direct specific guidelines to enhance …
A Model of Goal Dynamics in Organizations: a case study
2009
The purpose of the present work is to build a suitable system dynamics model for goal dynamics in organizations, as proposed by Barlas & Yasarcan (2008). The proposed model does not bear any ambition of being exhaustive: the main objective of this paper is to propose a model of goal dynamics in which Goal Setting, Management by Objectives and Training are viewed as human resource practices able to enhance workers’ goal commitment, and therefore, improve organizational performance. In the first part of this paper, an analysis of the Goal Setting Theory and the role of goal setting practices, in bettering worker’s performance, are stressed. In the second part, a case-study, the causal loop an…
Sex roles and sex ratios in animals
2022
In species with separate sexes, females and males often differ in their morphology, physiology and behaviour. Such sex-specific traits are functionally linked to variation in reproductive competition, mate choice and parental care, which have all been linked to sex roles. At the 150th anniversary of Darwin's theory on sexual selection, the question of why patterns of sex roles vary within and across species remains a key topic in behavioural and evolutionary ecology. New theoretical, experimental and comparative evidence suggests that variation in the adult sex ratio (ASR) is a key driver of variation in sex roles. Here, we first define and discuss the historical emergence of the sex role c…
Disentangling conditional effects of multiple regime shifts on Atlantic cod productivity
2020
AbstractRegime shifts are increasingly prevalent in the ecological literature. However, definitions vary, and many detection methods are subjective. Here, we employ an operationally objective means of identifying regime shifts, using a Bayesian online change-point detection algorithm able to simultaneously identify shifts in the mean and(or) variance of time series data. We detected multiple regime shifts in long-term (59-154 years) patterns of coastal Norwegian Atlantic cod (>70% decline) and putative drivers of cod productivity: North Atlantic Oscillation (NAO); sea-surface temperature; zooplankton abundance; fishing mortality (F). The consequences of an environmental or climate-relate…
miRNA Signature and Dicer Requirement during Human Endometrial Stromal Decidualization In Vitro
2012
Decidualization is a morphological and biochemical transformation of endometrial stromal fibroblast into differentiated decidual cells, which is critical for embryo implantation and pregnancy establishment. The complex regulatory networks have been elucidated at both the transcriptome and the proteome levels, however very little is known about the post-transcriptional regulation of this process. miRNAs regulate multiple physiological pathways and their de-regulation is associated with human disorders including gynaecological conditions such as endometriosis and preeclampsia. In this study we profile the miRNAs expression throughout human endometrial stromal (hESCs) decidualization and analy…
Signal reconstruction, modeling and simulation of a vehicle full-scale crash test based on Morlet wavelets
2012
Creating a mathematical model of a vehicle crash is a task which involves considerations and analysis of different areas which need to be addressed because of the mathematical complexity of a crash event representation. Therefore, to simplify the analysis and enhance the modeling process, in this paper a novel wavelet-based approach is introduced to reproduce acceleration pulse of a vehicle involved in a crash event. The acceleration of a colliding vehicle is measured in its center of gravity-this crash pulse contains detailed information about vehicle behavior throughout a collision. Three types of signal analysis are elaborated here: time domain analysis (i.e. description of kinematics of…