The skull of the Turks and Caicos rock iguana, (Squamata: Iguanidae).

We provide a detailed and first description of the skull, hyoid apparatus, and trachea of the Turks and Caicos rock iguana, (Squamata: Iguanidae). is a radiation of iguanas restricted to islands of the Caribbean Sea. Species of have high rates of endemism, and all species are severely threatened with extinction.

A new perspective on the taxonomy and systematics of Arvicolinae (Gray, 1821) and a new time-calibrated phylogeny for the clade.

Background: Arvicoline rodents are one of the most speciose and rapidly evolving mammalian lineages. Fossil arvicolines are also among the most common vertebrate fossils found in sites of Pliocene and Pleistocene age in Eurasia and North America. However, there is no taxonomically robust, well-supported, time-calibrated phylogeny for the group.

A Palaeogene stem crotaphytid () and the phylogenetic affinities of early fossil pleurodontan iguanians.

Pleurodonta is an ancient, diverse clade of iguanian lizard distributed primarily in the Western Hemisphere. Although the clade is a frequent subject of systematic research, phylogenetic resolution among the major pleurodontan clades is elusive. That uncertainty has complicated the interpretations of many fossil pleurodontans.

The affinities of the Late Triassic and the age of crown squamates.

Most living reptile diversity is concentrated in Squamata (lizards, including snakes), which have poorly known origins in space and time. Recently, † from the Late Triassic of the United Kingdom was described as the oldest crown squamate. If true, this result would push back the origin of all major lizard clades by 30-65 Myr and suggest that divergence times for reptile clades estimated using genomic and morphological data are grossly inaccurate.

Beyond pulsed inhibition: Alpha oscillations modulate attenuation and amplification of neural activity in the awake resting state.

Alpha oscillations are a distinctive feature of the awake resting state of the human brain. However, their functional role in resting-state neuronal dynamics remains poorly understood. Here we show that, during resting wakefulness, alpha oscillations drive an alternation of attenuation and amplification bouts in neural activity.

Criticality of neuronal avalanches in human sleep and their relationship with sleep macro- and micro-architecture.

Sleep plays a key role in preserving brain function, keeping brain networks in a state that ensures optimal computation. Empirical evidence indicates that this state is consistent with criticality, where scale-free neuronal avalanches emerge. However, the connection between sleep architecture and brain tuning to criticality remains poorly understood.

Elevational surveys of Sulawesi herpetofauna 1: Gunung Galang, Gunung Dako Nature Reserve.

The Indonesian island of Sulawesi has a unique geology and geography, which have produced an astoundingly diverse and endemic flora and fauna and a fascinating biogeographic history. Much biodiversity research has focused on the regional endemism in the island's Central Core and on its four peninsulas, but the biodiversity of the island's many upland regions is still poorly understood for most taxa, including amphibians and reptiles. Here, we report the first of several planned full-mountain checklists from a series of herpetological surveys of Sulawesi's mountains conducted by our team.

Power spectrum and critical exponents in the 2D stochastic Wilson-Cowan model.

The power spectrum of brain activity is composed by peaks at characteristic frequencies superimposed to a background that decays as a power law of the frequency, [Formula: see text], with an exponent [Formula: see text] close to 1 (pink noise). This exponent is predicted to be connected with the exponent [Formula: see text] related to the scaling of the average size with the duration of avalanches of activity. "Mean field" models of neural dynamics predict exponents [Formula: see text] and [Formula: see text] equal or near 2 at criticality (brown noise), including the simple branching model and the fully-connected stochastic Wilson-Cowan model.

User-centered design and development of TWIN-Acta: A novel control suite of the TWIN lower limb exoskeleton for the rehabilitation of persons post-stroke.

Introduction: Difficulties faced while walking are common symptoms after stroke, significantly reducing the quality of life. Walking recovery is therefore one of the main priorities of rehabilitation. Wearable powered exoskeletons have been developed to provide lower limb assistance and enable training for persons with gait impairments by using typical physiological movement patterns.

FITFES: A Wearable Myoelectrically Controlled Functional Electrical Stimulator Designed Using a User-Centered Approach.

Myoelectrically Controlled Functional Electrical Stimulation (MeCFES) has proven to be a useful tool in the rehabilitation of the hemiplegic arm. This paper reports the steps involved in the development of a wearable MeCFES device (FITFES) through a user-centered design. We defined the minimal viable features and functionalities requirements for the device design from a questionnaire-based survey among physiotherapists with experience in functional electrical stimulation.

A new extinct species of alligator lizard (Squamata: Elgaria) and an expanded perspective on the osteology and phylogeny of Gerrhonotinae.

Background: Alligator lizards (Gerrhonotinae) are a well-known group of extant North American lizard. Although many fossils were previously referred to Gerrhonotinae, most of those fossils are isolated and fragmentary cranial elements that could not be placed in a precise phylogenetic context, and only a handful of known fossils are articulated skulls. The fossil record has provided limited information on the biogeography and phylogeny of Gerrhonotinae.

Variation in the skulls of and (Anguidae, Gerrhonotinae) and implications for phylogenetics and fossil identification.

Background: There are limited data on intra- and interspecific osteological variation for many squamate clades. Those data are relevant for phylogenetic analyses that use osteological characters and for apomorphic identifications of fossils. We investigate whether morphological features in the skulls of extant gerrhonotine lizards can be used to distinguish taxa at the species- and genus-level and assess whether newly discovered intra- and interspecific osteological variation alters the utility of previously reported apomorphic features.

Effects of phylogenetic uncertainty on fossil identification illustrated by a new and enigmatic Eocene iguanian.

Fossil identifications made in a phylogenetic framework are beholden to specific tree hypotheses. Without phylogenetic consensus, the systematic provenance of any given fossil can be volatile. Paleobiogeographic and divergence time hypotheses are contingent on the accurate systematic placement of fossils.

Unusual lizard fossil from the Miocene of Nebraska and a minimum age for cnemidophorine teiids.

Teiid lizards are well represented in the fossil record and are common components of modern ecosystems in North and South America. Many fossils were referred to the cnemidophorine teiid group (whiptails, racerunners and relatives), particularly from North America. However, systematic interpretations of morphological features in cnemidophorines were hampered by the historically problematic taxonomy of the clade, and the biogeography and chronology of cnemidophorine evolution in North America is poorly understood from the fossil record.

Combined-evidence analyses of ultraconserved elements and morphological data: an empirical example in iguanian lizards.

Genomic datasets generated by next-generation sequencing are increasingly prevalent in phylogenetics, but morphological data are required to phylogenetically place fossils, corroborate molecular hypotheses and date phylogenies. Combined-evidence analyses provide an integrative assessment of tree topology. However, no attempt has been made to simultaneously analyse next-generation genomic datasets and morphological data, and the future of morphology in the context of genomic data is uncertain.

Novel and Bizarre Abnormalities of the Tooth Row in Side-Blotched Lizards (Uta) and Rock Lizards (Petrosaurus).

Multiple tooth rows along the dentary or maxilla are present in many bony and cartilaginous fishes but occur infrequently in amniotes. Although two partially overlapping rows of teeth or a few doubled tooth positions were both previously reported in extant and extinct lizards, multiple rows of teeth across the entire dental or maxillary shelf were not previously documented in any lizard taxon. Here, we report one specimen of the side-blotched lizard Uta stansburiana and two specimens of the rock lizard Petrosaurus mearnsi that have two or more marginal tooth rows that overlap for most of the dental shelf.

The first known fossil Uma: ecological evolution and the origins of North American fringe-toed lizards.

Background: Fossil evidence suggests that extant North American lizard genera (north of Mexico) evolved during the Miocene. Although fossils of the clade Phrynosomatidae (spiny lizards and sand lizards) have been reported, there have been no previously described fossils of the fringe-toed sand lizards (Uma). In the extant biota, Uma inhabit arid deserts, and members of the western clade of Uma are restricted to sand dunes or other habitats containing fine-grained sand.

Hysteresis, neural avalanches, and critical behavior near a first-order transition of a spiking neural network.

Many experimental results, both in vivo and in vitro, support the idea that the brain cortex operates near a critical point and at the same time works as a reservoir of precise spatiotemporal patterns. However, the mechanism at the basis of these observations is still not clear. In this paper we introduce a model which combines both these features, showing that scale-free avalanches are the signature of a system posed near the spinodal line of a first-order transition, with many spatiotemporal patterns stored as dynamical metastable attractors.

The skull of the gerrhonotine lizard Elgaria panamintina (Squamata: Anguidae).

We provide the first description of the skull, osteoderms, and hyoid apparatus of the poorly known alligator lizard Elgaria panamintina, and compare the cranial osteology of that species to the widespread and well-studied taxon Elgaria multicarinata. Patterns of morphological variation resulting from ontogenetic transformations and pathology are discussed. We employed x-ray computed tomography (CT) scans to examine two adult specimens of Elgaria panamintina and two adult specimens of Elgaria multicarinata, in addition to examining multiple traditionally prepared skeletal specimens of the latter species.

Critical phenomena at a first-order phase transition in a lattice of glow lamps: Experimental findings and analogy to neural activity.

Networks of non-linear electronic oscillators have shown potential as physical models of neural dynamics. However, two properties of brain activity, namely, criticality and metastability, remain under-investigated with this approach. Here, we present a simple circuit that exhibits both phenomena.

Alternation of up and down states at a dynamical phase-transition of a neural network with spatiotemporal attractors.

Complex collective activity emerges spontaneously in cortical circuits in vivo and in vitro, such as alternation of up and down states, precise spatiotemporal patterns replay, and power law scaling of neural avalanches. We focus on such critical features observed in cortical slices. We study spontaneous dynamics emerging in noisy recurrent networks of spiking neurons with sparse structured connectivity.