957 resultados para 270501 Animal Systematics, Taxonomy and Phylogeny


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Longstanding taxonomic ambiguity and uncertainty exist in the identification of the common (M. mustelus) and blackspotted (M. punctulatus) smooth-hound in the Adriatic Sea. The lack of a clear and accurate method of morphological identification, leading to frequent misidentification, prevents the collation of species-specific landings and survey data for these fishes and hampers the delineation of the distribution ranges and stock boundaries of the species. In this context, adequate species-specific conservation and management strategies can not be applied without risks of population declining and local extinction. In this thesis work I investigated the molecular ecology of the two smooth-hound sharks which are abundant in the demersal trawl surveys carried out in the NC Adriatic Sea to monitor and assess the fishery resources. Ecological and evolutionary relationships were assessed by two molecular tests: a DNA barcoding analysis to improve species identification (and consequently the knowledge of their spatial ecology and taxonomy) and a hybridization assay based on the nuclear codominant marker ITS2 to evaluate reproductive interactions (hybridization or gene introgression). The smooth-hound sharks (N=208) were collected during the MEDITS 2008 and 2010 campaigns along the Italian and Croatian coasts of the Adriatic Sea, in the Sicilian Channel and in the Algerian fisheries. Since the identification based on morphological characters is not strongly reliable, I performed a molecular identification of the specimens producing for each one the cytochrome oxidase subunit 1 (COI) gene sequence (ca. 640 bp long) and compared them with reference sequences from different databases (GenBank and BOLD). From these molecular ID data I inferred the distribution of the two target species in the NC Adriatic Sea. In almost the totality of the MEDITS hauls I found no evidence of species sympatry. The data collected during the MEDITS survey showed an almost different distribution of M. mustelus (confined along the Italian coasts) and M. punctulatus (confined along the Croatian coasts); just one sample (Gulf of Venice, where probably the ranges of the species overlap) was found to have catches of both the species. Despite these data results suggested no interaction occurred between my two target species at least during the summertime (the period in which MEDITS survey is carried out), I still wanted to know if there were inter-species reproductive interactions so I developed a simple molecular genetic method to detect hybridization. This method is based on DNA sequence polymorphism among species in the nuclear ribosomal Internal Transcribed Spacer 2 locus (ITS2). Its application to the 208 specimens collected raised important questions regarding the ecology of this two species in the Adriatic Sea. In fact results showed signs of hybridization and/or gene introgression in two sharks collected during the trawl survey of 2008 and one collected during the 2010 one along the Italian and Croatian coasts. In the case that it will be confirmed the hybrid nature of these individuals, a spatiotemporal overlapping of the mating behaviour and ecology must occur. At the spatial level, the northern part of the Adriatic Sea (an area where the two species occur with high frequency of immature individuals) could likely play the role of a common nursery area for both species.

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The Brachiopoda of the Marine Protected Area “Secche di Tor Paterno”, Central Tyrrhenian Sea, have been investigated in order to give a first glance of the diversity of the brachiopods of this area and provide a new report on the Mediterranean Brachiopod fauna. Four species were reported: Novocrania anomala (Müller, 1776), Megathiris detruncata (Gmelin, 1790), Joania cordata (Risso,1826) and Argyrotheca cuneata (Risso,1826). For all the four species a morphological analysis was carried out. For the two most abundant species, J.cordata and A. cuneata, a morphometric study, based on thickness/width and length/width scattergrams, was carried out, in order to investigate their variability. Size-frequency distributions relative to the three dimensions of the shell were also computed, aimed at a evaluation of population dynamics of these two species. The results showed that, for both species, the parameters which most determine the rise of the shell during the growth of animal are width and length and that frequency distributions are mainly bi- or plurymodal and that they are difficult to interpret, as reported by other studies. Analysis of drill holes found on the shell of some specimens of the two same species revealed a predatory origin and that three different predators are responsible for them. Partial sequences of two different genetic markers, the Internal Transcribed Spacer 1 (ITS1) and the cytochrome oxidase subunit 1 (COI), were used to investigate the phylogenetic relationship between two populations of the eurybathic brachiopod species Gryphus vitreus (Born,1778) across the strait of Gibraltar. This represents the first genetic population study on brachiopods. Results from AMOVA and Bayesian analysis performed on 31 specimens highlighted no genetic differentiation indicating a likely panmixia, dispite the lecitotrophic development of the species.

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Ontology design and population -core aspects of semantic technologies- re- cently have become fields of great interest due to the increasing need of domain-specific knowledge bases that can boost the use of Semantic Web. For building such knowledge resources, the state of the art tools for ontology design require a lot of human work. Producing meaningful schemas and populating them with domain-specific data is in fact a very difficult and time-consuming task. Even more if the task consists in modelling knowledge at a web scale. The primary aim of this work is to investigate a novel and flexible method- ology for automatically learning ontology from textual data, lightening the human workload required for conceptualizing domain-specific knowledge and populating an extracted schema with real data, speeding up the whole ontology production process. Here computational linguistics plays a fundamental role, from automati- cally identifying facts from natural language and extracting frame of relations among recognized entities, to producing linked data with which extending existing knowledge bases or creating new ones. In the state of the art, automatic ontology learning systems are mainly based on plain-pipelined linguistics classifiers performing tasks such as Named Entity recognition, Entity resolution, Taxonomy and Relation extraction [11]. These approaches present some weaknesses, specially in capturing struc- tures through which the meaning of complex concepts is expressed [24]. Humans, in fact, tend to organize knowledge in well-defined patterns, which include participant entities and meaningful relations linking entities with each other. In literature, these structures have been called Semantic Frames by Fill- 6 Introduction more [20], or more recently as Knowledge Patterns [23]. Some NLP studies has recently shown the possibility of performing more accurate deep parsing with the ability of logically understanding the structure of discourse [7]. In this work, some of these technologies have been investigated and em- ployed to produce accurate ontology schemas. The long-term goal is to collect large amounts of semantically structured information from the web of crowds, through an automated process, in order to identify and investigate the cognitive patterns used by human to organize their knowledge.

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In this study, facilitated anastomosis using an anastomotic device was compared to conventional hand-sewn (HS) vascular anastomosis in an animal model.

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Recent research with several species of nonhuman primates suggests sophisticated motor-planning abilities observed in human adults may be ubiquitous among primates. However, there is considerable variability in the extent to which these abilities are expressed across primate species. In the present experiment, we explore whether the variability in the expression of anticipatory motor-planning abilities may be attributed to cognitive differences (such as tool use abilities) or whether they may be due to the consequences of morphological differences (such as being able to deploy a precision grasp). We compared two species of New World monkeys that differ in their tool use abilities and manual dexterity: squirrel monkeys, Saimiri sciureus (less dexterous with little evidence for tool use) and tufted capuchins, Sapajus apella (more dexterous and known tool users). The monkeys were presented with baited cups in an untrained food extraction task. Consistent with the morphological constraint hypothesis, squirrel monkeys frequently showed second-order motor planning by inverting their grasp when picking up an inverted cup, while capuchins frequently deployed canonical upright grasping postures. Findings suggest that the lack of ability for precision grasping may elicit more consistent second-order motor planning, as the squirrel monkeys (and other species that have shown a high rate of second-order planning) have fewer means of compensating for inefficient initial postures. Thus, the interface between morphology and motor planning likely represents an important factor for understanding both the ontogenetic and phylogenetic origins of sophisticated motor-planning abilities. (C) 2013 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

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Killing of animals is an important task to be performed by veterinarians. Killing decisions and their implementation often raise ethical questions. As a result of an interdisciplinary workshop targeting the subject "killing of animals" with veterinarians and ethicists, a three-dimensional dimension scheme was developed. Whereas the first two dimensions are focused on the animal's past and future life and are discussed with regard to life quality and life accomplishment (the "telos"), the third dimension incorporates the reason to kill and may integrate the concept of dignity. This form of dignity and the weighing of interests are applied to example scenarios and the resulting responsibilities of veterinarians and society are discussed.

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Turtles experience numerous modifications in the morphological, physiological, and mechanical characteristics of their shells through ontogeny. Although a general picture is available of the nature of these modifications, few quantitative studies have been conducted on changes in turtle shell shape through ontogeny, and none on changes in strength or rigidity. This study investigates the morphological and mechanical changes that juvenile Trachemys scripta elegans undergo as they increase in size. Morphology and shell rigidity were quantified in a sample of 36 alcohol-preserved juvenile Trachemys scripta elegans. Morphometric information was used to create finite element models of all specimens. These models were used to assess the mechanical behavior of the shells under various loading conditions. Overall, we find that turtles experience complementary changes in size, shape, deformability, and relative strength as they grow. As turtles age their shells become larger, more elongate, relatively flatter, and more rigid. These changes are associated with decreases in relative (size independent) strength, even though the shells of larger turtles are stronger in an absolute sense. Decreased deformability is primarily due to changes in the size of the animals. Residual variation in deformability cannot be explained by changes in shell shape. This variation is more likely due to changes in the degree of connectedness of the skeletal elements in the turtle's shells, along with changes in the thickness and degree of mineralization of shell bone. We suggest that the mechanical implications of shell size, shape, and deformability may have a large impact on survivorship and development in members of this species as they mature. J. Morphol. 275:391-397, 2014. 2013 Wiley Periodicals, Inc. Copyright 2013 Wiley Periodicals, Inc.

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BACKGROUND AND PURPOSE: The major goal of acute ischemic stroke treatment is fast and sufficient recanalization. Percutaneous transluminal balloon angioplasty (PTA) and/or placement of a stent might achieve both by compressing the thrombus at the occlusion site. This study assesses the feasibility, recanalization rate, and complications of the 2 techniques in an animal model. MATERIALS AND METHODS: Thirty cranial vessels of 7 swine were occluded by injection of radiopaque thrombi. Fifteen vessel occlusions were treated by PTA alone and 15, by placement of a stent and postdilation. Recanalization was documented immediately after treatment and after 1, 2, and 3 hours. Thromboembolic events and dissections were documented. RESULTS: PTA was significantly faster to perform (mean, 16.6 minutes versus 33.0 minutes for stent placement; P < .001), but the mean recanalization rate after 1 hour was significantly better after stent placement compared with PTA alone (67.5% versus 14.6%, P < .001). Due to the self-expanding force of the stent, vessel diameter further increased with time, whereas the recanalization result after PTA was prone to reocclusion. Besides thromboembolic events related to the passing maneuvers at the occlusion site, no thrombus fragmentation and embolization occurred during balloon inflation or stent deployment. Flow to side branches could also be restored at the occlusion site because it was possible to direct thrombus compression. CONCLUSIONS: Stent placement and postdilation proved to be much more efficient in terms of acute and short-term vessel recanalization compared with PTA alone.

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Pasteurella multocida is commonly found in the oral cavity of cats and dogs. In humans it is known as an opportunistic pathogen after bites from these animals. Phenotypic identification of P. multocida based on biochemical reactions is often limited and usually only done on a species level, even though 3 subspecies are described. For molecular taxonomy and diagnostic purposes a phylogenetic analysis of the three subspecies of P. multocida based on their 16S rRNA (rrs) gene sequence was therefore carried out. We found P. multocida subsp. septica on a distinguished branch on the phylogenetic tree of Pasteurellaceae, due to a 1.5% divergence of its rrs gene compared to the two other, more closely related subspecies multocida and gallicida. This phylogenetic divergence can be used for the identification of P. multocida subsp. septica by rrs gene determination since they form a phylogenetically well isolated and defined group as shown with a set of feline isolates. Comparison to routine phenotypic identification shows the advantage of the sequence-based identification over conventional methods. It is therefore helpful for future unambiguous identification and molecular taxonomy of P. multocida as well as for epidemiological investigations.

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Pastures containing hay-type and grazing tolerant alfalfa hybrids were grazed in a season-long or complementary rotational stocking system with Nfertilized smooth bromegrass. The pastures were stocked at a seasonal density of .8 cow-calf pairs per acre for 120 days in 1998 and 141 days in 1999. Pastures were intensively managed by daily stripstocking with the assumptions that 50% of live forage was available and daily live dry matter consumption of each cow-calf pair was 3.5% of the cow’s body weight. First-cutting forage was harvested as hay from 40% of the pasture acres to remove excess forage growth early in the grazing season. Grazing occurred on the remaining 60% of each pasture for the first 44 and 54 days and 100% of each pasture after days 45 and 55 in 1998 and 1999, respectively. Proportions of ‘Amerigraze’ and ‘Affinity’ alfalfa in the live forage dry matter decreased by 70% and 55% in pastures stocked season-long and by 60% and 42% in pastures used for complementary stocking (alfalfa type, p<.05; grazing management, p<.05) in 1998, but decreased by a mean of 72% and was unaffected by hybrid or stocking system in 1999. Cows grazing either alfalfa hybrid by either grazing system had greater weight gains during the breeding and overall grazing seasons and greater increases in body condition score pre-breeding and during the breeding season than the cows that grazed smooth bromegrass for the entire season in 1998. Also, cows grazing either alfalfa hybrid in the season-long system had greater breeding season increases in body condition score than cows grazing alfalfa in the complementary system with smooth bromegrass in 1998. Cows grazing in the season-long alfalfa system had greater prebreeding season weight (p<.10) increases and condition score (p<.05) increases than cows grazing alfalfa in the complementary system in 1999. Daily and seasonal body weight gains of calves were not affected (p>.10) by the presence of alfalfa in 1998 or by alfalfa type and grazing management in 1998 and 1999. Total animal production (cow and calf) in 1998 was greater (p<.10) from the season-long alfalfa pastures compared with the complementary stocked pastures. Total (p<.10) and live (p<.05) forage masses, estimated by monthly clippings, were greater in September of 1998 from the season-long alfalfa pastures than pastures using alfalfa for complementary stocking. Total (p<.10) and live (p<.05) forage masses were greater in August of 1999 from season-long alfalfa pastures than pastures using alfalfa for complementary stocking.

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Animal production, hay production and feeding, winter forage composition changes, and summer pasture yields and nutrient composition of a year-round grazing system for spring-calving and fall-calving cows were compared to those of a conventional, minimal land system. Cows in the year-round and minimal land systems grazed forage from smooth bromegrassorchardgrass-birdsfoot trefoil (SB-O-T) pastures at 1.67 and 3.33 acres, respectively, per cow in the summer. During the summer, SB-O-T pastures in the year-round grazing system also were grazed by stockers at 1.67 stockers per acre, and spring-calving and fall-calving cows grazed smooth bromegrass–red clover (SB-RC) and endophyte-free tall fescue–red clover (TF-RC) at 2.5 acres per cow for approximately 45 days in midsummer. In the year-round grazing system, spring-calving cows grazed corn crop residues at 2.5 acres per cow and stockpiled SB-RC pastures at 2.5 acres per cow; fallcalving cows grazed stockpiled TF-RC pastures at 2.5 acres per cow during winter. In the minimal land system, in winter, cows were maintained in a drylot on first-cutting hay harvested from 62.5–75% of the pasture acres during summer. Hay was fed to maintain a body condition score of 5 on a 9-point scale for springcalving cows in both systems and a body condition score of 3 for fall-calving cows in the year-round system. Over 3 years, mean body weights of fall-calving cows in the year-round system did not differ from the body weights of spring-calving cows in either system, but fall-calving cows had higher (P < .05) body condition scores compared to spring-calving cows in either system. There were no differences among all groups of cows in body condition score changes over the winter grazing season (P > .05). During the summer grazing season, fall-calving cows in the year- round system and springcalving cows in the minimal land system gained more body condition and more weight (P < .05) than springcalving cows in the year-round grazing system. Fall calves in the year-round system had higher birth weights, lower weaning weights, and lower average preweaning daily gains compared to either group of spring calves (P < .05). However, there were no significant differences for birth weights, weaning weights, or average pre-weaning daily gains between spring calves in either system over the 3-year experiment (P > .05). The amount of total growing animal production (calves and stockers) per acre for each system did not differ in any year (P > .05). Over the 3-year experiment, 1.9 ton more hay was fed per cow and 1 ton more hay was fed per cow–calf pair in the minimal land system compared to the year-round grazing system (P < .05).

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Neuromodulation is essential to many functions of the nervous system. In the simple gastropod mollusk Aplysia californica, neuromodulation of the circuits for the defensive withdrawal reflexes has been associated with several forms of learning. In the present work, the neurotransmitters and neural circuitry which contribute to the modulation of the tail-siphon withdrawal reflex were examined.^ A recently-identified neuropeptide transmitter, buccalin A was found to modulate the biophysical properties of the sensory neurons that mediate the reflex. The actions of buccalin A on the sensory neurons were compared with those of the well-characterized modulatory transmitter serotonin, and convergence and divergence in the actions of these two transmitters were evaluated. Buccalin A dramatically increased the excitability of sensory neurons and occluded further enhancement of excitability by serotonin. Buccalin A produced no significant change in spike duration, and it did not block serotonin-induced spike broadening. Voltage-clamp analysis revealed the currents that may be involved in the effects on spike duration and excitability. Buccalin A decreased an outward current similar to the S-K$\sp+$ current (I$\sb{\rm K,S}$). Buccalin A appeared to occlude further modulation of I$\sb{\rm K,S}$ by serotonin, but did not block serotonin-induced modulation of the voltage-dependent delayed rectifier K$\sp+$ current (I$\sb{\rm K,V}$). These results suggest that buccalin A converges on some, but not all, of the same subcellular modulatory pathways as serotonin.^ In order to begin to understand neuromodulation in a more physiological context for the tail-siphon withdrawal reflex, the modulatory circuitry for the tail-withdrawal circuit was examined. Mechanoafferent neurons in the J cluster of the cerebral ganglion were identified as elements of a modulatory circuit for the reflex. Excitatory and inhibitory connections were observed between the J cells and the pleural sensory neurons, the tail motor neurons, and several classes of interneurons for the tail-siphon withdrawal circuit. The J cells produced both fast and slow PSPs in these neurons. Of particular interest was the ability of the J cells to produce slow EPSPs in the pleural sensory neurons. These slow EPSPs were associated with an increase in the excitability of the sensory neurons. The J cells appear to mediate both sensory and modulatory inputs to the circuit for the tail-siphon withdrawal reflex from the anterior part of the animal. ^

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Previous studies from our lab have established that large molecular weight mucin glycoproteins are major apically-disposed components of mouse uterine epithelial cells in vitro (Valdizan et al., (1992) J. Cell. Physiol. 151:451-465). The present studies demonstrate that Muc-1 represents one of the apically-disposed mucin glycoproteins of mouse uterine epithelia, and that Muc-1 protein and mRNA expression are regulated in the peri-implantation stage mouse uterus by ovarian steroids. Muc-1 expression is high in the proestrous and estrous stages, and decreases during diestrous. Both Muc-1 protein and mRNA levels decline to barely detectable levels by day 4 of pregnancy, i.e., prior to the time of blastocyst attachment. In contrast, Muc-1 expression in the cervix and vagina is maintained during this same period. Delayed implantation was established in pregnant mice by ovariectomy and maintained by administration of exogenous progesterone. Initiation of implantation was triggered by coinjection of progesterone maintained mice with a nidatory dose of 17$\beta$-estradiol. Muc-1 levels in the uterine epithelia of progesterone maintained mice declined to similar low levels as observed on day 4 of normal pregnancy. Coinjection of estradiol did not alter Muc-1 expression suggesting that down-regulation of Muc-1 is a progesterone dominated event. This was confirmed in ovariectomized, non-pregnant mice which displayed stimulation of Muc-1 expression following 6 hr of estradiol injection. Estradiol stimulated Muc-1 expression was inhibited by the pure antiestrogen, ICI 164,384. While progesterone alone had no effect on Muc-1 expression, it antagonized estradiol action in this regard. Injection of pregnant mice with the antiprogestin, RU 486, a known implantation inhibitor, on day 3 of pregnancy restored high level expression of Muc-1 mRNA on day 4, indicating that down-regulation of Muc-1 is progesterone receptor-mediated. Muc-1 appears to function as an anti-adhesive molecule at the apical cell surface of mouse uterine epithelial cells. Treatment of polarized cultures of mouse uterine epithelial cells with O-sialoglycoprotein endopeptidase reduced mucin expression in vitro, by about 50%, and converted polarized uterine epithelia to a functionally receptive state. Similarly, ablation of Muc-1 in Muc-1 null mice resulted in polarized uterine epithelia that were functionally receptive as compared to their wild-type counterparts in vitro. Collectively, these data indicate that Muc-1 and other mucins function as anti-adhesive molecules and that reduction or removal of these molecules is a prerequisite for the generation of a receptive uterine state. ^

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Cerebrovascular diseases are significant causes of death and disability in humans. Improvements in diagnostic and therapeutic approaches strongly rely on adequate gyrencephalic, large animal models being demanded for translational research. Ovine stroke models may represent a promising approach but are currently limited by insufficient knowledge regarding the venous system of the cerebral angioarchitecture. The present study was intended to provide a comprehensive anatomical analysis of the intracranial venous system in sheep as a reliable basis for the interpretation of experimental results in such ovine models. We used corrosion casts as well as contrast-enhanced magnetic resonance venography to scrutinize blood drainage from the brain. This combined approach yielded detailed and, to some extent, novel findings. In particular, we provide evidence for chordae Willisii and lateral venous lacunae, and report on connections between the dorsal and ventral sinuses in this species. For the first time, we also describe venous confluences in the deep cerebral venous system and an 'anterior condylar confluent' as seen in humans. This report provides a detailed reference for the interpretation of venous diagnostic imaging findings in sheep, including an assessment of structure detectability by in vivo (imaging) versus ex vivo (corrosion cast) visualization methods. Moreover, it features a comprehensive interspecies-comparison of the venous cerebral angioarchitecture in man, rodents, canines and sheep as a relevant large animal model species, and describes possible implications for translational cerebrovascular research.