Primary sensory cortices contain distinguishable spatial patterns of activity for each sense

Whether primary sensory cortices are essentially multisensory or whether they respond to only one sense is an emerging debate in neuroscience. Here we use a multivariate pattern analysis of functional magnetic resonance imaging data in humans to demonstrate that simple and isolated stimuli of one sense elicit distinguishable spatial patterns of neuronal responses, not only in their corresponding primary sensory cortex, but in other primary sensory cortices. These results indicate that primary sensory cortices, traditionally regarded as unisensory, contain unique signatures of other senses and, thereby, prompt a reconsideration of how sensory information is coded in the human brain

Foraminiferal biostratigraphy and palaeoenvironmental analysis of the mid-Cretaceous limestones in the southern Tibetan plateau

This study of mid-Cretaceous foraminifera from the Linzhou, the Coqen and the Xigaze Basins in the southern Tibetan Plateau has provided the first high resolution biostratigraphic description of these limestones and interpretation of their paleoenvironmental settings. The fossil assemblages are dominated primarily by orbitolinid larger benthic foraminifera. We reassessed the identification of many taxa, dividing the South Tibetan sedimentary successions of Aptian to Early Cenomanian age into eight new foraminiferal biozones (TLK1 a–h): (i) (TLK1a) a shallow reefal environment corresponding to planktonic foraminifera zone (PZ) Aptian 1–2, dominated by Palorbitolina and Praeorbitolina spp.; (ii) (TLK1b) a transgressive, reefal to forereefal environment corresponding to PZ Aptian 3, characterized by the first appearance of Mesorbitolina parva; (iii) (TLK1c) a shallow reefal to backreef environment of Late Aptian (PZ Aptian 4) age, characterized by the first appearance of Mesorbitolina texana; (iv) (TLK1d) a transgressive phase of forereef to an inner neritic environment of Albian (PZ Albian 1) age, characterized by the first appearance of Cuneolina pavonia; (v) (TLKe) an open-marine reefal environment of Albian (PZ Albian 2) age, with assemblages dominated by flat to slightly conical orbitolinids, characterized by the first appearance of Palorbitolinoides hedini; (vi) (TLK1f) a shallow, open-marine reefal to forereef environment of Middle Albian (PZ Albian 3) age, dominated by flat and convex orbitolinids, and characterized by the first appearance of Mesorbitolina aperta; (vii) (TLK1g) a reefal to forereef environment of end Albian (PZ Albian 4) age, characterized by the appearance of Conicorbitolina cf. cuvillieri and Pseudochoffatella cuvillieri, and in which Early Aptian species of Praeorbitolina cf. wienandsi have been recorded for the first time from the Late Albian; (viii) (TLK1h) a shallow reefal environment of Early Cenomanian age characterized by the first appearance of Conicorbitolina sp. A and Nezzazata conica. The eight new biozones provided biostratigraphic correlation of the Langshan, Sangzugang and Takena Formations in the Lhasa terrane, while the observed evolution of the environmentally controlled microfacies corresponds closely with the current, inferred global sea-level variation of the period. The almost continuous sedimentary sequences studied allowed previously defined orbitolinid phylogenetic linages to be confirmed

Ultralow-frequency neural entrainment to pain

Nervous systems exploit regularities in the sensory environment to predict sensory input, adjust behavior, and thereby maximize fitness. Entrainment of neural oscillations allows retaining temporal regularities of sensory information, a prerequisite for prediction. Entrainment has been extensively described at the frequencies of periodic inputs most commonly present in visual and auditory landscapes (e.g., >0.5 Hz). An open question is whether neural entrainment also occurs for regularities at much longer timescales. Here, we exploited the fact that the temporal dynamics of thermal stimuli in natural environment can unfold very slowly. We show that ultralow-frequency neural oscillations preserved a long-lasting trace of sensory information through neural entrainment to periodic thermo-nociceptive input as low as 0.1 Hz. Importantly, revealing the functional significance of this phenomenon, both power and phase of the entrainment predicted individual pain sensitivity. In contrast, periodic auditory input at the same ultralow frequency did not entrain ultralow-frequency oscillations. These results demonstrate that a functionally significant neural entrainment can occur at temporal scales far longer than those commonly explored. The non-supramodal nature of our results suggests that ultralow-frequency entrainment might be tuned to the temporal scale of the statistical regularities characteristic of different sensory modalities

Waves of Change: Brain Sensitivity to Differential, not Absolute, Stimulus Intensity is Conserved Across Humans and Rats

Living in rapidly changing environments has shaped the mammalian brain toward high sensitivity to abrupt and intense sensory events-often signaling threats or affordances requiring swift reactions. Unsurprisingly, such events elicit a widespread electrocortical response (the vertex potential, VP), likely related to the preparation of appropriate behavioral reactions. Although the VP magnitude is largely determined by stimulus intensity, the relative contribution of the differential and absolute components of intensity remains unknown. Here, we dissociated the effects of these two components. We systematically varied the size of abrupt intensity increases embedded within continuous stimulation at different absolute intensities, while recording brain activity in humans (with scalp electroencephalography) and rats (with epidural electrocorticography). We obtained three main results. 1) VP magnitude largely depends on differential, and not absolute, stimulus intensity. This result held true, 2) for both auditory and somatosensory stimuli, indicating that sensitivity to differential intensity is supramodal, and 3) in both humans and rats, suggesting that sensitivity to abrupt intensity differentials is phylogenetically well-conserved. Altogether, the current results show that these large electrocortical responses are most sensitive to the detection of sensory changes that more likely signal the sudden appearance of novel objects or events in the environment

Late Cretaceous to early Paleogene foraminiferal biozones in the Tibetan Himalayas, and a pan-Tethyan foraminiferal correlation scheme

This investigation of Upper Cretaceous and lower Paleogene sediments from the Tibetan Himalayas, based on three stratigraphic sections from the southern margin of Asian Plate and nine sections from the northern Indian Plate margin, provides the first high resolution biostratigraphic description of the region. The sedimentary successions from these two plate margins evolved during the following depositional stages, which we here divide into eleven new biozones (TLK2-3 and TP1-9); (i) an outer neritic stage from the Coniacian to the Maastrichtian, dominated by keeled planktonic foraminifera (PF), such as Globotruncana (TLK2); (ii) a latest Maastrichtian forereef assemblage dominated by Lepidorbitoides, Omphalocyclus andOrbitoides (TLK3); (iii) an early Paleocene, intermittently occurring backreef/shallow reefal warm environment with benthic assemblages dominated by small miliolids and rotaliids, such as Daviesina and Lockhartia (TP1-2); (iv) a late Paleocene-early Eocene, shallow reefal environment dominated by warm water forms, such as Alveolina, Assilina and Nummulites (TP3-7); (v) a depositional stage showing a slight deepening of the reef, with forereef assemblages, lasting until the end of theYpresian (TP8); (vi) a final, early Lutetian depositional stage characterised by the complete disappearance of the larger benthic foraminifera (LBF) and their reefal environment, which was replaced by PF assemblages with intense reworking of pelagic facies triggered by the tectonics of the India-Asia collision (TP9). During the course of this study two unnamed species have been identified and described, Lepidorbitoides sp. A and Discocyclina sp. A, from the Xigaze forearc basin. The high resolution depositional and biostratigraphic scheme defined here for the southern Himalayan region gives greater insight into the general evolution of this globally important tectonic region.We have confirmed earlier observations that many LBF forms appear about 1Ma later in the eastern part of Tethys than they do in the west, reflecting their previously inferred gradual eastern paleogeographic migration. Additionally, this study has allowed us to refine the biostratigraphic ranges of some LBF of the Eastern Tethys, and for the first time to exactly correlate these Eastern Tethyan zones with the Shallow Benthic Zones (SBZs) of the Western Tethys

Human brain responses to concomitant stimulation of Aδ and C nociceptors

Intense radiant heat pulses concomitantly activate Aδ- and C-fiber skin nociceptors, and elicit a typical double sensation: an initial Aδ-related pricking pain is followed by a C-related prolonged burning sensation. It has been repeatedly reported that C-fiber laser-evoked potentials (C-LEPs) become detectable only when the concomitant activation of Aδ-fibers is avoided or reduced. Given that the saliency of the eliciting stimulus is a major determinant of LEPs, one explanation for these observations is that the saliency of the C-input is smaller than that of the preceding Aδ-input. However, even if the saliency of the C-input is reduced because of the preceding Aδ-input, a C-LEP should still be visible even when preceded by an Aδ-LEP response. Here we tested this hypothesis by applying advanced signal processing techniques (peak alignment and time-frequency decomposition) to electroencephalographic data collected in two experiments conducted in 34 and 96 healthy participants. We show that, when using optimal stimulus parameters (delivering >80 stimuli within a small skin territory), C-LEPs can be reliably detected in most participants. Importantly, C-LEPs are observed even when preceded by Aδ-LEPs, both in average waveforms and single trials. By providing quantitative information about several response properties of C-LEPs (latency jitter, stimulus-response and perception-response functions, dependency on stimulus repetitions and stimulated area), these results define optimal parameters to record C-LEPs simply and reliably. These findings have important clinical implications for assessing small-fiber function in neuropathies and neuropathic pain

The Epidemiology of Lead Toxicity in Adults: Measuring Dose and Consideration of Other Methodologic Issues

We review several issues of broad relevance to the interpretation of epidemiologic evidence concerning the toxicity of lead in adults, particularly regarding cognitive function and the cardiovascular system, which are the subjects of two systematic reviews that are also part of this mini-monograph. Chief among the recent developments in methodologic advances has been the refinement of concepts and methods for measuring individual lead dose in terms of appreciating distinctions between recent versus cumulative doses and the use of biological markers to measure these parameters in epidemiologic studies of chronic disease. Attention is focused particularly on bone lead levels measured by K-shell X-ray fluorescence as a relatively new biological marker of cumulative dose that has been used in many recent epidemiologic studies to generate insights into lead’s impact on cognition and risk of hypertension, as well as the alternative method of estimating cumulative dose using available repeated measures of blood lead to calculate an individual’s cumulative blood lead index. We review the relevance and interpretation of these lead biomarkers in the context of the toxico-kinetics of lead. In addition, we also discuss methodologic challenges that arise in studies of occupationally and environmentally exposed subjects and those concerning race/ethnicity and socioeconomic status and other important covariates

Finite-region stabilization via dynamic output feedback for 2-D Roesser models

Finite-region stability (FRS), a generalization of finite-time stability, has been used to analyze the transient behavior of discrete two-dimensional (2-D) systems. In this paper, we consider the problem of FRS for discrete 2-D Roesser models via dynamic output feedback. First, a sufficient condition is given to design the dynamic output feedback controller with a state feedback-observer structure, which ensures the closed-loop system FRS. Then, this condition is reducible to a condition that is solvable by linear matrix inequalities. Finally, viable experimental results are demonstrated by an illustrative example

Multiscale correlative tomography: an investigation of creep cavitation in 316 stainless steel

Creep cavitation in an ex-service nuclear steam header Type 316 stainless steel sample is investigated through a multiscale tomography workflow spanning eight orders of magnitude, combining X-ray computed tomography (CT), plasma focused ion beam (FIB) scanning electron microscope (SEM) imaging and scanning transmission electron microscope (STEM) tomography. Guided by microscale X-ray CT, nanoscale X-ray CT is used to investigate the size and morphology of cavities at a triple point of grain boundaries. In order to understand the factors affecting the extent of cavitation, the orientation and crystallographic misorientation of each boundary is characterised using electron backscatter diffraction (EBSD). Additionally, in order to better understand boundary phase growth, the chemistry of a single boundary and its associated secondary phase precipitates is probed through STEM energy dispersive X-ray (EDX) tomography. The difference in cavitation of the three grain boundaries investigated suggests that the orientation of grain boundaries with respect to the direction of principal stress is important in the promotion of cavity formation