Constructing a rich and continuous visual experience requires computing specific details across views as well as integrating similarities across views. In this paper, we report functional magnetic ...resonance imaging (fMRI) evidence that these distinct computations may occur in two scene-sensitive regions in the brain, the parahippocampal place area (PPA) and retrosplenial cortex (RSC). Participants saw different snapshot views from panoramic scenes, which represented clearly different views, but appeared to come from the same scene. Using fMRI adaptation, we tested whether the PPA and RSC treated these panoramic views as the same or different. In the panoramic condition, three different views from a single panoramic scene were presented. We did not find any attenuation for panoramic repeats in the PPA, showing viewpoint-specificity. In contrast, RSC showed significant attenuation for the panoramic condition, showing viewpoint-integration. However, when the panoramic views were not presented in a continuous way, both the specificity in the PPA and the integration in RSC were lost. These results demonstrate that the PPA and RSC compute different properties of scenes: the PPA focuses on selective discrimination of different views while RSC focuses on the integration of scenes under the same visual context. These complementary functions of the PPA and RSC enable both specific and integrative representations of scenes across several viewpoints.
Spontaneous subarachnoid haemorrhage Claassen, Jan; Park, Soojin
The Lancet (British edition),
09/2022, Letnik:
400, Številka:
10355
Journal Article
Recenzirano
Subarachnoid haemorrhage (SAH) is the third most common subtype of stroke. Incidence has decreased over past decades, possibly in part related to lifestyle changes such as smoking cessation and ...management of hypertension. Approximately a quarter of patients with SAH die before hospital admission; overall outcomes are improved in those admitted to hospital, but with elevated risk of long-term neuropsychiatric sequelae such as depression. The disease continues to have a major public health impact as the mean age of onset is in the mid-fifties, leading to many years of reduced quality of life. The clinical presentation varies, but severe, sudden onset of headache is the most common symptom, variably associated with meningismus, transient or prolonged unconsciousness, and focal neurological deficits including cranial nerve palsies and paresis. Diagnosis is made by CT scan of the head possibly followed by lumbar puncture. Aneurysms are commonly the underlying vascular cause of spontaneous SAH and are diagnosed by angiography. Emergent therapeutic interventions are focused on decreasing the risk of rebleeding (ie, preventing hypertension and correcting coagulopathies) and, most crucially, early aneurysm treatment using coil embolisation or clipping. Management of the disease is best delivered in specialised intensive care units and high-volume centres by a multidisciplinary team. Increasingly, early brain injury presenting as global cerebral oedema is recognised as a potential treatment target but, currently, disease management is largely focused on addressing secondary complications such as hydrocephalus, delayed cerebral ischaemia related to microvascular dysfunction and large vessel vasospasm, and medical complications such as stunned myocardium and hospital acquired infections.
The urgency for clean and secure energy has stimulated a global resurgence in searching for advanced electrical energy storage systems. For now and the foreseeable future, batteries remain the most ...promising electrical energy storage systems for many applications, from portable electronics to emerging technologies such as electric vehicles and smart grids, by potentially offering significantly improved performance, energy efficiencies, reliability, and energy security while also permitting a drastic reduction in fuel consumption and emissions. The energy and power storage characteristics of batteries critically impact the commercial viability of these emerging technologies. For example, the realization of electric vehicles hinges on the availability of batteries with significantly improved energy and power density, durability, and reduced cost. Further, the design, performance, portability, and innovation of many portable electronics are limited severely by the size, power, and cycle life of the existing batteries. Creation of nanostructured electrode materials represents one of the most attractive strategies to dramatically enhance battery performance, including capacity, rate capability, cycling life, and safety. This review aims at providing the reader with an understanding of the critical scientific challenges facing the development of advanced batteries, various unique attributes of nanostructures or nano-architectures applicable to lithium-ion and lithium-air batteries, the latest developments in novel synthesis and fabrication procedures, the unique capabilities of some powerful,
in situ characterization techniques vital to unraveling the mechanisms of charge and mass transport processes associated with battery performance, and the outlook for future-generation batteries that exploit nanoscale materials for significantly improved performance to meet the ever-increasing demands of emerging technologies.
One of the most widely used models for specifying functional requirements is a use case model. The viewpoint of the use case model that views a system as a black box focuses on descriptions of ...external interactions between the system and related environments. However, for embedded systems that do not disclose most implementation logics outside the system, black box-based use case models may experience the drawback that considerable information that must be defined for system developments is omitted. To solve this shortcoming, several studies have been proposed on the use of kind of white box technique in which the dynamic behaviors of embedded systems are defined first using a state diagram and the results are reflected in the requirement specifications. However, white box-based modeling has not been widely adopted by developers due to tasks that require a lot of time in the requirement analysis phase in the initial phase of the software development life cycle. This study proposes a gray box-based requirement specification method as a trade-off between two contradictory elements (the amount of information required to develop an embedded system and the cost of the effort required during the requirement analysis phase) in terms of the two approaches, the black and the white box-based models. The proposed method suggests that an appropriate depth level of embedded system modeling is required to define the requirements. This study also proposes a mechanism that automatically generates an application programming interface for each component based on the created model. The proposed method was applied to the development of a camera sensor controller in a mobile phone, and the case results proved the feasibility of the method through discussion of the application results.
We demonstrate high-performance polymer solar cells using the plasmonic effect of multipositional silica-coated silver nanoparticles. The location of the nanoparticles is critical for increasing ...light absorption and scattering via enhanced electric field distribution. The device incorporating nanoparticles between the hole transport layer and the active layer achieves a power conversion efficiency of 8.92% with an external quantum efficiency of 81.5%. These device efficiencies are the highest values reported to date for plasmonic polymer solar cells using metal nanoparticles.
The mammalian sperm midpiece has a unique double-helical structure called the mitochondrial sheath that wraps tightly around the axoneme. Despite the remarkable organization of the mitochondrial ...sheath, the molecular mechanisms involved in mitochondrial sheath formation are unclear. In the process of screening testis-enriched genes for functions in mice, we identified armadillo repeat-containing 12 (ARMC12) as an essential protein for mitochondrial sheath formation. Here, we engineered
-null mice, FLAG-tagged
knock-in mice, and TBC1 domain family member 21 (
)-null mice to define the functions of ARMC12 in mitochondrial sheath formation in vivo. We discovered that absence of ARMC12 causes abnormal mitochondrial coiling along the flagellum, resulting in reduced sperm motility and male sterility. During spermiogenesis, sperm mitochondria in
-null mice cannot elongate properly at the mitochondrial interlocking step which disrupts abnormal mitochondrial coiling. ARMC12 is a mitochondrial peripheral membrane protein and functions as an adherence factor between mitochondria in cultured cells. ARMC12 in testicular germ cells interacts with mitochondrial proteins MIC60, VDAC2, and VDAC3 as well as TBC1D21 and GK2, which are required for mitochondrial sheath formation. We also observed that TBC1D21 is essential for the interaction between ARMC12 and VDAC proteins in vivo. These results indicate that ARMC12 uses integral mitochondrial membrane proteins VDAC2 and VDAC3 as scaffolds to link mitochondria and works cooperatively with TBC1D21. Thus, our studies have revealed that ARMC12 regulates spatiotemporal mitochondrial dynamics to form the mitochondrial sheath through cooperative interactions with several proteins on the sperm mitochondrial surface.
The synthesis of a new type of redox‐active covalent triazine framework (rCTF) material, which is promising as an anode for Li‐ion batteries, is reported. After activation, it has a capacity up to ...≈1190 mAh g−1 at 0.5C with a current density of 300 mA g−1 and a high cycling stability of over 1000 discharge/charge cycles with a stable Coulombic efficiency in an rCTF/Li half‐cell. This rCTF has a high rate performance, and at a charging rate of 20C with a current density of 12 A g−1 and it functions well for over 1000 discharge/charge cycles with a reversible capacity of over 500 mAh g−1. By electrochemical analysis and theoretical calculations, it is found that its lithium‐storage mechanism involves multi‐electron redox‐reactions at anthraquinone, triazine, and benzene rings by the accommodation of Li. The structural features and progressively increased structural disorder of the rCTF increase the kinetics of infiltration and significantly shortens the activation period, yielding fast‐charging Li‐ion half and full cells even at a high capacity loading.
A redox‐active covalent triazine framework is used as an anode material for lithium‐ion batteries. The progressive structural deformation through activation provides a larger number of accessible active Li‐storage sites and efficient Li‐ion/electron diffusion, which gives a high specific capacity (≈1190 mAh g−1 over 1500 charge/discharge cycles) and a rate performance of over 500 mAh g−1 at 20C rate.
A novel architecture consisting of Si nanowires internally grown from porous graphite is synthesized by etching of graphite with a lamellar structure via a VLS (vapor–liquid–solid) process. This ...strategy gives the high electrode density of 1.5 g/cm3, which is comparable with practical anode of the Li-ion battery. Our product demonstrates a high volumetric capacity density of 1363 mAh/cm3 with 91% Coulombic efficiency and high rate capability of 568 mAh/cm3 even at a 5C rate. This good electrochemical performance allows porous graphite to offer free space to accommodate the volume change of Si nanowires during cycling and the electron transport to efficiently be improved between active materials.
Behavioral and computational studies suggest that visual scene analysis rapidly produces a rich description of both the objects and the spatial layout of surfaces in a scene. However, there is still ...a large gap in our understanding of how the human brain accomplishes these diverse functions of scene understanding. Here we probe the nature of real-world scene representations using multivoxel functional magnetic resonance imaging pattern analysis. We show that natural scenes are analyzed in a distributed and complementary manner by the parahippocampal place area (PPA) and the lateral occipital complex (LOC) in particular, as well as other regions in the ventral stream. Specifically, we study the classification performance of different scene-selective regions using images that vary in spatial boundary and naturalness content. We discover that, whereas both the PPA and LOC can accurately classify scenes, they make different errors: the PPA more often confuses scenes that have the same spatial boundaries, whereas the LOC more often confuses scenes that have the same content. By demonstrating that visual scene analysis recruits distinct and complementary high-level representations, our results testify to distinct neural pathways for representing the spatial boundaries and content of a visual scene.
High-theoretical capacity and low working potential make silicon ideal anode for lithium ion batteries. However, the large volume change of silicon upon lithiation/delithiation poses a critical ...challenge for stable battery operations. Here, we introduce an unprecedented design, which takes advantage of large deformation and ensures the structural stability of the material by developing a two-dimensional silicon nanosheet coated with a thin carbon layer. During electrochemical cycling, this carbon coated silicon nanosheet exhibits unique deformation patterns, featuring accommodation of deformation in the thickness direction upon lithiation, while forming ripples upon delithiation, as demonstrated by in situ transmission electron microscopy observation and chemomechanical simulation. The ripple formation presents a unique mechanism for releasing the cycling induced stress, rendering the electrode much more stable and durable than the uncoated counterparts. This work demonstrates a general principle as how to take the advantage of the large deformation materials for designing high capacity electrode.
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