48 research outputs found
Lateral palatal foramina are not widespread in Artiodactyla and imply baleen in extinct mysticetes
Osservatorio Territoriale Droga e Tossicodipendenze. Il fenomeno delle dipendenze nel territorio della ASL della Provincia di Sondrio. Dati anno 2008.
Report on the state of legal and illegal substances use in the territory of Sondrio Province.Il Report analizza il fenomeno delle dipendenze nella provincia di Sondrio. La descrizione del fenomeno si sviluppa intorno all\u27analisi degli indicatori individuati dall\u27Osservatorio Europeo delle Dipendenze di Lisbona (OEDT): 1-uso di sostanze nella popolazione generale (questo indicatore va a rilevare i comportamenti nei confronti di alcol e sostanze psicoattive da parte della popolazione generale); 2-prevalenza d\u27uso problematico delle sostanze psicoattive; 3-domanda di trattamento degli utilizzatori di sostanze; 4-mortalit? degli utilizzatori di sostanze; 5-malattie infettive. Altri due importanti indicatori che si stanno sviluppando, e che vengono qui illustrati, sono l\u27analisi delle Schede di Dimissione Ospedaliera (SDO) e gli indicatori relativi alle conseguenza sociali dell\u27uso di droghe (criminalit? droga correlata). Inoltre sono state applicate diverse metodologie standard di stima sia per quantificare la quota parte sconosciuta di utilizzatori di sostanze che non afferiscono ai servizi, sia per identificarne alcune caratteristiche
Coastal high-frequency radars in the Mediterranean ??? Part 1: Status of operations and a framework for future development
Due to the semi-enclosed nature of the Mediterranean
Sea, natural disasters and anthropogenic activities impose
stronger pressures on its coastal ecosystems than in any
other sea of the world.With the aim of responding adequately
to science priorities and societal challenges, littoral waters
must be effectively monitored with high-frequency radar
(HFR) systems. This land-based remote sensing technology
can provide, in near-real time, fine-resolution maps of the
surface circulation over broad coastal areas, along with reliable
directional wave and wind information. The main goal
of this work is to showcase the current status of the Mediterranean
HFR network and the future roadmap for orchestrated
actions. Ongoing collaborative efforts and recent progress of
this regional alliance are not only described but also connected
with other European initiatives and global frameworks,
highlighting the advantages of this cost-effective instrument
for the multi-parameter monitoring of the sea state.
Coordinated endeavors between HFR operators from different
multi-disciplinary institutions are mandatory to reach a
mature stage at both national and regional levels, striving to
do the following: (i) harmonize deployment and maintenance
practices; (ii) standardize data, metadata, and quality control
procedures; (iii) centralize data management, visualization,
and access platforms; and (iv) develop practical applications
of societal benefit that can be used for strategic planning and
informed decision-making in the Mediterranean marine environment.
Such fit-for-purpose applications can serve for
search and rescue operations, safe vessel navigation, tracking
of marine pollutants, the monitoring of extreme events,
the investigation of transport processes, and the connectivity
between offshore waters and coastal ecosystems. Finally, future
prospects within the Mediterranean framework are discussed
along with a wealth of socioeconomic, technical, and
scientific challenges to be faced during the implementatio
The Comparative Osteology of the Petrotympanic Complex (Ear Region) of Extant Baleen Whales (Cetacea: Mysticeti)
Anatomical comparisons of the ear region of baleen whales (Mysticeti) are provided through detailed osteological descriptions and high-resolution photographs of the petrotympanic complex (tympanic bulla and petrosal bone) of all extant species of mysticete cetaceans. Salient morphological features are illustrated and identified, including overall shape of the bulla, size of the conical process of the bulla, morphology of the promontorium, and the size and shape of the anterior process of the petrosal. We place our comparative osteological observations into a phylogenetic context in order to initiate an exploration into petrotympanic evolution within Mysticeti.The morphology of the petrotympanic complex is diagnostic for individual species of baleen whale (e.g., sigmoid and conical processes positioned at midline of bulla in Balaenoptera musculus; confluence of fenestra cochleae and perilymphatic foramen in Eschrichtius robustus), and several mysticete clades are united by derived characteristics. Balaenids and neobalaenids share derived features of the bulla, such as a rhomboid shape and a reduced anterior lobe (swelling) in ventral aspect, and eschrichtiids share derived morphologies of the petrosal with balaenopterids, including loss of a medial promontory groove and dorsomedial elongation of the promontorium. Monophyly of Balaenoidea (Balaenidae and Neobalaenidae) and Balaenopteroidea (Balaenopteridae and Eschrichtiidae) was recovered in phylogenetic analyses utilizing data exclusively from the petrotympanic complex.This study fills a major gap in our knowledge of the complex structures of the mysticete petrotympanic complex, which is an important anatomical region for the interpretation of the evolutionary history of mammals. In addition, we introduce a novel body of phylogenetically informative characters from the ear region of mysticetes. Our detailed anatomical descriptions, illustrations, and comparisons provide valuable data for current and future studies on the phylogenetic relationships, evolution, and auditory physiology of mysticetes and other cetaceans throughout Earth's history
The Magnitude of Global Marine Species Diversity
Background: The question of how many marine species exist is important because it provides a metric for how much we do and do not know about life in the oceans. We have compiled the first register of the marine species of the world and used this baseline to estimate how many more species, partitioned among all major eukaryotic groups, may be discovered.
Results: There are ∼226,000 eukaryotic marine species described. More species were described in the past decade (∼20,000) than in any previous one. The number of authors describing new species has been increasing at a faster rate than the number of new species described in the past six decades. We report that there are ∼170,000 synonyms, that 58,000–72,000 species are collected but not yet described, and that 482,000–741,000 more species have yet to be sampled. Molecular methods may add tens of thousands of cryptic species. Thus, there may be 0.7–1.0 million marine species. Past rates of description of new species indicate there may be 0.5 ± 0.2 million marine species. On average 37% (median 31%) of species in over 100 recent field studies around the world might be new to science.
Conclusions: Currently, between one-third and two-thirds of marine species may be undescribed, and previous estimates of there being well over one million marine species appear highly unlikely. More species than ever before are being described annually by an increasing number of authors. If the current trend continues, most species will be discovered this century
Callorhinus gilmorei n. sp., (Carnivora: Otariidae) from the San Diego Formation (Blancan) and its implications for otariid phylogeny
Volume: 21Start Page: 111End Page: 12
The Phylogenetic Relationships and Biogeography of True Porpoises (Mammalia: Phocoenidae) Based On Morphological Data
Prior studies of phylogenetic relationships among phocoenids based on morphology and molecular sequence data conflict and yield unresolved relationships among species. This study evaluates a comprehensive set of cranial, postcranial, and soft anatomical characters to infer interrelationships among extant species and several well-known fossil phocoenids, using two different methods to analyze polymorphic data: polymorphic coding and frequency step matrix. Our phylogenetic results confirmed phocoenid monophyly. The division of Phocoenidae into two subfamilies previously proposed was rejected, as well as the alliance of the two extinct genera Salumiphocaena and Piscolithax with Phocoena dioptrica and Phocoenoides dalli. Extinct phocoenids are basal to all extant species. We also examined the origin and distribution of porpoises within the context of this phylogenetic framework. Phocoenid phylogeny together with available geologic evidence suggests that the early history of phocoenids was centered in the North Pacific during the middle Miocene, with subsequent dispersal into the southern hemisphere in the middle Pliocene. A cooling period in the Pleistocene allowed dispersal of the southern ancestor of Phocoena sinusinto the North Pacific (Gulf of California)
Recommended from our members
Vertical Structure of Ocean Surface Currents Under High Winds from Massive Arrays of Drifters
Abstract. Very near surface ocean currents are dominated by wind and wave forcing and have large impacts on the transport of buoyant materials in the ocean, but have proved difficult to measure with many modern instrumentations. Here, observations of ocean currents at two depths within the first meter of the surface are made utilizing trajectory data from both drogued and undrogued CARTHE drifters, which have draft depths of 60 cm and 5 cm, respectively. Trajectory data of dense, co-located drogued and undrogued drifters, were collected during the LAgrangian Submesoscale ExpeRiment (LASER) that took place from January to March of 2016 in the Northern Gulf of Mexico. Examination of the drifter velocities reveals that the surface currents become strongly wind- and wave-driven during periods of high wind, with the pre-existing regional circulation having a smaller, but non-negligible, influence on the total surface velocity. During these high wind events, we deconstruct the full surface current velocities captured by each drifter type into their wind- and wave-driven components after subtracting an estimate for the regional circulation which pre-exists each wind event. In order to capture the regional circulation in the absence of strong wind and wave forcing, a Lagrangian variational method is used to create hourly velocity fields for both drifter types separately, during the hours preceding each high wind event. Synoptic wind and wave output data from the Unified Wave INterface-Coupled Model (UWIN-CM), a fully coupled atmosphere, wave and ocean circulation model, are used for analysis. The wind-driven component of the surface current exhibits a rotation to the right with depth between the two surface layers measured. We find that the averaged wind-driven surface current from 0-5 cm (0-60 cm) travels at ~ 3.4-6.0 % (~ 2.3-4.1 %) of the wind speed, and is deflected ~ 5°-55° (~ 30-85°) to the right of the wind, reaching higher deflection angles at higher wind speeds. Results provide new insight to the vertical shear present in wind-driven surface currents under high winds, which have vital implications for any surface transport problem