Conceptual Advances Research Articles

A base-controlled switch of SO2 reincorporation in photocatalyzed radical difunctionalization of alkenes

A base-controlled switch of SO2 reincorporation in photocatalyzed radical difunctionalization of alkenes

Is human face recognition lateralized to the right hemisphere due to neural competition with left-lateralized visual word recognition? A critical review.

The right hemispheric lateralization of face recognition, which is well documented and appears to be specific to the human species, remains a scientific mystery. According to a long-standing view, the evolution of language, which is typically substantiated in the left hemisphere, competes with the cortical space in that hemisphere available for visuospatial processes, including face recognition. Over the last decade, a specific hypothesis derived from this view according to which neural competition in the left ventral occipito-temporal cortex with selective representations of letter strings causes right hemispheric lateralization of face recognition, has generated considerable interest and research in the scientific community. Here, a systematic review of studies performed in various populations (infants, children, literate and illiterate adults, left-handed adults) and methodologies (behavior, lesion studies, (intra)electroencephalography, neuroimaging) offers little if any support for this reading lateralized neural competition hypothesis. Specifically, right-lateralized face-selective neural activity already emerges at a few months of age, well before reading acquisition. Moreover, consistent evidence of face recognition performance and its right hemispheric lateralization being modulated by literacy level during development or at adulthood is lacking. Given the absence of solid alternative hypotheses and the key role of neural competition in the sensory-motor cortices for selectivity of representations, learning, and plasticity, a revised language-related neural competition hypothesis for the right hemispheric lateralization of face recognition should be further explored in future research, albeit with substantial conceptual clarification and advances in methodological rigor.

Single-Detector Spectrometer Using a Superconducting Nanowire.

Designing a spectrometer without the need for wavelength multiplexing optics can effectively reduce the complexity and physical footprint. On the basis of the computational spectroscopic strategy and combining a broadband-responsive dynamic detector, we successfully demonstrate an optics-free single-detector spectrometer that maps the tunable quantum efficiency of a superconducting nanowire into a matrix to build a solvable mathematical equation. Such a spectrometer can realize a broadband spectral responsivity ranging from 660 to 1900 nm. The spectral resolution at the telecom is sub-10 nm, exceeding the energy resolving capacity of existing infrared single-photon detectors. Meanwhile, benefiting from the optics-free setup, precise time-of-flight measurements can be simultaneously achieved. We have demonstrated a spectral LiDAR with eight spectral channels. This spectrometer scheme paves the way for applying superconducting nanowire detectors in multifunctional spectroscopy and represents a conceptual advancement for on-chip spectroscopy and spectral imaging.

Brain Functional Connectivity as Biomarker for Propofol-Induced Alterations of Consciousness.

Understanding neural correlates of consciousness and its alterations poses a grand challenge for modern neuroscience. Even though recent years of research have shown many conceptual and empirical advances, the evolution of a system that can track anesthesia-induced loss of consciousness is hindered by the lack of reliable markers. The work presented herein estimates the functional connectivity (FC) between 21 scalp electroencephalogram (EEG) recordings to evaluate its utility in characterizing changes in brain networks during propofol sedation. The sedation dataset in the University of Cambridge data repository was used for analyses. FC was estimated using the debiased estimator of the squared Weighted Phase Lag Index (dWPLI2). Spectral FC networks before, during, and after sedation was considered for 5 EEG sub-bands. Results demonstrated significantly higher alpha band FC during baseline, mild and moderate sedation, and recovery stages. A striking association between frontal brain activity and propofol-sedation was also noticed. Furthermore, inhibition of frontal to parietal and frontal to occipital connections were observed as characteristic features of propofol-induced alterations in consciousness. A random subspace ensemble framework using logistic model tree as the base classifier, and 18 functional connections as features, yielded a cross-validation accuracy of 98.75% in discriminating baseline, mild and moderate sedation, and recovery stages. These findings validate that EEG-based FC can reliably distinguish altered conscious states associated with anaesthesia.

Chiral Effective Field Theory after Thirty Years: Nuclear Lattice Simulations

The introduction of chiral effective field theory by Steven Weinberg three decades ago has had a profound and lasting impact on nuclear physics. This brief review explores the impact of Weinberg's work on the field of nuclear lattice simulations. Rather than a summary of technical details, an effort is made to present the conceptual advances that made much of the recent progress possible.

Gender, malice, obligation and the state: Separated mothers’ experiences of administrative burdens with Australia's child support program

AbstractThis article provides an empirical account of Herd and Moynihan's theory of administrative burdens as they apply to Australian child support recipients. Interviews with 41 separated mothers revealed how they were compelled to engage in the child support system and then required to expend significant time and effort undertaking administrative work on behalf of the state, often for little financial benefit. Unlike the examples provided by Herd and Moynihan, in this study, it was found that child support system burdens could be used by aggrieved fathers to inflict financial and psychological harms on their ex‐partners. The state accepted fathers’ imposition of costs on mothers as they shared a financial interest in maintaining women's burdens. As a result, this paper provides three conceptual advancements on the existing theory, by articulating: how administrative burdens can be created and applied by non‐government third parties, in this case individual ex‐family members; how the state can acquiesce to the imposition of harms if these align with their interests; and how the state distributes obligations and autonomy along social lines, such as, in this case, along the lines of class and gender.

Advancing climate resilient development pathways since the IPCC’s fifth assessment report

Development processes and action on climate change are closely interlinked. This is recognised by the Intergovernmental Panel on Climate Change (IPCC) in its fifth assessment report, which reports on climate-resilient pathways, understood as development trajectories towards sustainable development which include adaptation and mitigation. The upcoming sixth assessment report dedicates a chapter to climate resilient development pathways. In this context, this paper asks what conceptual and empirical advances on climate resilient development pathways were made since the fifth assessment report. Through a literature review, this paper analyses goals and approaches for climate resilient development pathways, and discusses what conceptual advances have and could still be made. We find little evidence of dedicated concept development. Rather, we observe conceptual ambiguity. Literature showed four non-exclusive clusters of approaches: (a) climate action oriented, (b) social-learning and co-creation oriented, (c) mainstreaming oriented and (d) transformation oriented. We recommend operationalising climate resilient development pathways as the process of consolidating climate action and development decisions towards long-term sustainable development. This process requires explicit engagement with aspirations of actors, and connecting past developments with future aspirations and understandings of risk. Working with multiple pathways allows us to embed flexibility, anticipation and learning in planning. A greater focus is needed on issues linked to justice and equity as climate resilient development pathways will inevitably involve trade-offs. Substantiating the concept of climate resilient development pathways has the potential to bridge climate and development perspectives, which may otherwise remain separated in development and climate policy, practice and science.

Photoremovable Protecting Groups: Across the Light Spectrum to Near- Infrared Absorbing Photocages.

We discuss the past decade of progress in the field of photoremovable protecting groups that allowed the development of photocages activatable by near-IR light and highlight the individual conceptual advancements that lead to general guidelines to design new such photoremovable protecting groups. We emphasize the importance of understanding the individual photochemical reaction mechanisms that was necessary to achieve this progress and provide an outlook of the subsequent steps to facilitate a swift translation of this research into clinical praxis. Since this issue of CHIMIA is dedicated to the late Prof. Thomas Bally, we decided to provide a personal perspective on the field to which he contributed himself. We tried to write this review with the general readership of CHIMIA in mind in a hope to pay a tribute to the extraordinary dedication and clarity with which Thomas Bally used to explain abstract chemical concepts to his students or colleagues. We are uncertain whether we matched such challenge but we believe that he would have liked such approach very much.

Multianion Transition Metal Compounds: Synthesis, Regulation, and Electrocatalytic Applications

ConspectusEnergy electrocatalysis is an essential part for the modern energy network serving as the core technique in many electrochemical energy devices such as batteries, fuel cells, electrolyzers, etc. Developing high-performance electrocatalysts, especially the pursuit for higher intrinsic electrocatalytic activity, is the eternal theme for high-efficiency energy electrocatalysis. Transition metal compounds are highly considered as promising high-performance electrocatalysts due to their facile fabrication, well-defined structure, and encouraging intrinsic activity. However, further promotion on intrinsic electrocatalytic activity of conventional transition metal compounds encounters an unavoidable bottleneck originated from the rigid homoanion structure with limited choice of anions. Facing the above issue, heteroanion substitution on pristine transition metal compounds has been proposed in some recent research. Their unique structure and properties that distinguish them from routine transition metal compounds have attracted wide attention to reveal distinct electronic structures, synthesis methodologies, and functions in energy electrocatalysis for future application.Typically, multianion transition metal compound is a type of transition metal compounds containing two or more types of anions, where different anions co-occupy the same type of sites to construct the heteroanion structure. The heteroanion structure is the core feature that distinguishes multianion transition metal compounds from routine transition metal compounds, which is regarded as a double-edged sword. On one hand, considering the huge radius difference between various types of anions, the heteroanion structure is metastable. Therefore, the synthesis and morphology regulation on multianion transition metal compounds are quite challengeable. On the other hand, the highly regulable heteroanion structure affords considerable opportunities on fundamental investigation on the structure–performance relationship as well as electrocatalytic activity enhancement via rational electronic structure modulation toward practical applications.In this Account, we summarize our and the communities’ efforts on the investigation of multianion transition metal compounds as a new branch of material science. We start with a basic background on their definition and general properties. Then we conduct an in-depth discussion on the synthesis of multianion transition metal compounds via anionic exchanging strategy. The advances on morphology regulation are subsequently highlighted. Furthermore, their electrocatalytic applications are presented where the mechanism on their high intrinsic activity is summarized from the perspective of fundamental principles of chemistry and material science. Finally, we end the Account with a brief overview of the current challenges and promising directions to join different voices and efforts on the conceptual advances and potential applications for multianion transition metal compounds.

Understanding and Modeling Forest Disturbance Interactions at the Landscape Level

Disturbances, both natural and anthropogenic, affect the configuration, composition, and function of forested ecosystems. Complex system behaviors emerge from the interactions between disturbance regimes, the vegetation response to those disturbances, and their interplay with multiple drivers (climate, topography, land use, etc.) across spatial and temporal scales. Here, we summarize conceptual advances and empirical approaches to disturbance interaction investigation, and used those insights to evaluate and categorize 146 landscape modeling studies emerging from a systematic review of the literature published since 2010. Recent conceptual advances include formal disaggregation of disturbances into their constituent components, embedding disturbance processes into system dynamics, and clarifying terminology for interaction factors, types, and ecosystem responses. Empirical studies investigating disturbance interactions now span a wide range of approaches, including (most recently) advanced statistical methods applied to an expanding set of spatial and temporal datasets. Concurrent development in spatially-explicit landscape models, informed by these empirical insights, integrate the interactions among natural and anthropogenic disturbances by coupling these processes to account for disturbance stochasticity, disturbance within and across scales, and non-linear landscape responses to climate change. Still, trade-offs between model elegance and complexity remain. We developed an index for the degree of process integration (i.e., balance of static vs. dynamic components) within a given disturbance agent and applied it to the studies from our systematic review. Contemporary model applications in this line of research have applied a wide range process integration, depending on the specific question, but also limited in part by data and knowledge. Non-linear “threshold” behavior and cross-scaled interactions remain a frontier in temperate, boreal, and alpine regions of North America and Europe, while even simplistic studies are lacking from other regions of the globe (e.g., subtropical and tropical biomes). Understanding and planning for uncertainty in system behavior—including disturbance interactions—is paramount at a time of accelerated anthropogenic change. While progress in landscape modeling studies in this area is evident, work remains to increase model transparency and confidence, especially for understudied regions and processes. Moving forward, a multi-dimensional approach is recommended to address the uncertainties of complex human-ecological dynamics.

Seismic Metashielding by a Line of Resonators Over a Granular Layer

Seismic metamaterials have been the subject of much recent interest, with notable conceptual advances and the demonstration of possible full-scale effectiveness in earthquake protection. Here, through a fine analysis of the dispersion properties and behavior of resonators introduced in a laboratory scale setup, we propose a strategy for the design of an efficient metaseismic barrier. When positioned onto an unconsolidated granular layer, rigid masses of nontrivial shape become elastic resonators by coupling with the relatively soft propagation medium. Additionally, they affect the mechanical boundary conditions and subsurface medium properties through the added weight. We demonstrate that all these ingredients can be rationally combined to improve the shielding effect and control the seismic waves.

The elegant complexity of mammalian ecto-5'-nucleotidase (CD73).

Purinergic signaling is a fundamental mechanism used by all cells to control their internal activities and interact with the environment. A key component of the purinergic system, the enzyme ecto-5'-nucleotidase (CD73) catalyzes the last step in the extracellular metabolism of ATP to form adenosine. Efforts to harness the therapeutic potential of endogenous adenosine in cancer have culminated in the ongoing clinical development of multiple CD73-targeting antibodies and small-molecule inhibitors. However, recent studies are painting an increasingly complex picture of CD73 mRNA and protein regulation and function in cellular homeostasis, physiological adaptation, and disease development. This review discusses the latest conceptual and methodological advances that are helping to unravel the complexity of this important enzyme that was identified nearly 90 years ago.

The effect of antioxidants in Ehrlich Ascites Cancer.

A fundamental goal in molecular oncology is to unravel the underlying mechanisms which cause the cell transformation. In line with this approach, genome-wide functional screening approaches have revealed exciting insights into heterogeneous nature of cancer. Rapidly expanding horizons of research have unraveled myriad of pathways which play instrumental role in carcinogenesis and metastasis. Oxidative stress has also been reported to be significantly involved in cancer onset and progression. In line with this approach, oxidative stress modulating chemicals have always been sharply divided into antioxidants and oxidative stress-inducing agents. Conceptual and experimental advancements have enabled us to critically analyze full potential of these two different groups of chemicals in cancer chemoprevention. Different antioxidants are currently being analyzed in different phases of clinical trials. Although it has been reported in the literature that antioxidant supplements reduce tumor cells in some tumors or cause volume reduction in solid tumor sizes, there is no definite consensus. Therefore, an antioxidant supplement guideline based on more detailed clinical research and as a result of these is needed to achieve the best care for cancer patients and to avoid risky treatments for cancer patients.

A Focused Review of Neural Recording and Stimulation Techniques With Immune-Modulatory Targets.

The complex interactions established between the nervous and immune systems have been investigated for a long time. With the advent of small and portable devices to record and stimulate nerve activity, researchers from many fields began to be interested in how nervous activity can elicit immune responses and whether this activity can be manipulated to trigger specific immune responses. Pioneering works demonstrated the existence of a cholinergic inflammatory reflex, capable of controlling the systemic inflammatory response through a vagus nerve-mediated modulation of the spleen. This work inspired many different areas of technological and conceptual advancement, which are here reviewed to provide a concise reference for the main works expanding the knowledge on vagus nerve immune-modulatory capabilities. In these works the enabling technologies of peripheral nervous activity recordings were implemented and embody the current efforts aimed at controlling neural activity with modulating functions in immune response, both in experimental and clinical contexts.

Luminescent First-Row Transition Metal Complexes.

Precious and rare elements have traditionally dominated inorganic photophysics and photochemistry, but now we are witnessing a paradigm shift toward cheaper and more abundant metals. Even though emissive complexes based on selected first-row transition metals have long been known, recent conceptual breakthroughs revealed that a much broader range of elements in different oxidation states are useable for this purpose. Coordination compounds of V, Cr, Mn, Fe, Co, Ni, and Cu now show electronically excited states with unexpected reactivity and photoluminescence behavior. Aside from providing a compact survey of the recent conceptual key advances in this dynamic field, our Perspective identifies the main design strategies that enabled the discovery of fundamentally new types of 3d-metal-based luminophores and photosensitizers operating in solution at room temperature.

Next-Generation Gene Therapy for Parkinson's Disease Using Engineered Viral Vectors.

Recent technological and conceptual advances have resulted in a plethora of exciting novel engineered adeno associated viral (AAV) vector variants. They all have unique characteristics and abilities. This review summarizes the development and their potential in treating Parkinson’s disease (PD). Clinical trials in PD have shown over the last decade that AAV is a safe and suitable vector for gene therapy but that it also is a vehicle that can benefit significantly from improvement in specificity and potency. This review provides a concise collection of the state-of-the-art for synthetic capsids and their utility in PD. We also summarize what therapeutical strategies may become feasible with novel engineered vectors, including genome editing and neuronal rejuvenation.

What Is the Role of Thalamostriatal Circuits in Learning Vocal Sequences?

Basal ganglia (BG) circuits integrate sensory and motor-related information from the cortex, thalamus, and midbrain to guide learning and production of motor sequences. Birdsong, like speech, is comprised of precisely sequenced vocal elements. Learning song sequences during development relies on Area X, a vocalization related region in the medial striatum of the songbird BG. Area X receives inputs from cortical-like pallial song circuits and midbrain dopaminergic circuits and sends projections to the thalamus. It has recently been shown that thalamic circuits also send substantial projections back to Area X. Here, we outline a gated-reinforcement learning model for how Area X may use signals conveyed by thalamostriatal inputs to direct song learning. Integrating conceptual advances from recent mammalian and songbird literature, we hypothesize that thalamostriatal pathways convey signals linked to song syllable onsets and offsets and influence striatal circuit plasticity via regulation of cholinergic interneurons (ChIs). We suggest that syllable sequence associated vocal-motor information from the thalamus drive precisely timed pauses in ChIs activity in Area X. When integrated with concurrent corticostriatal and dopaminergic input, this circuit helps regulate plasticity on medium spiny neurons (MSNs) and the learning of syllable sequences. We discuss new approaches that can be applied to test core ideas of this model and how associated insights may provide a framework for understanding the function of BG circuits in learning motor sequences.

Linking resilience, vulnerability, social capital and risk awareness for crisis and disaster research

AbstractCrisis and disaster research has extensively contributed to theoretical, conceptual, methodological and empirical advances in the understanding of resilience, vulnerability, social capital and risk awareness. These concepts identify complex social phenomena, which are intensified, in both positive and negative terms, by crises and disasters. However, the accumulation of knowledge about these notions has produced a vast range of definitions, which affects the way they are used in the study of crises and disasters. This paper sets a research agenda, by promoting a conceptual model to help simplify and make more researchable these complex concepts. This model stems from a triangulation of methods, with the goal of providing more researchable definitions of these notions and of illustrating linkages among them, seldom addressed in the way this model suggests, in the context of the crisis management cycle.

Conceptual Advances in Control of Inflammation by the RNA-Binding Protein Tristetraprolin.

Regulated changes in mRNA stability are critical drivers of gene expression adaptations to immunological cues. mRNA stability is controlled mainly by RNA-binding proteins (RBPs) which can directly cleave mRNA but more often act as adaptors for the recruitment of the RNA-degradation machinery. One of the most prominent RBPs with regulatory roles in the immune system is tristetraprolin (TTP). TTP targets mainly inflammation-associated mRNAs for degradation and is indispensable for the resolution of inflammation as well as the maintenance of immune homeostasis. Recent advances in the transcriptome-wide knowledge of mRNA expression and decay rates together with TTP binding sites in the target mRNAs revealed important limitations in our understanding of molecular mechanisms of TTP action. Such orthogonal analyses lead to the discovery that TTP binding destabilizes some bound mRNAs but not others in the same cell. Moreover, comparisons of various immune cells indicated that an mRNA can be destabilized by TTP in one cell type while it remains stable in a different cell linage despite the presence of TTP. The action of TTP extends from mRNA destabilization to inhibition of translation in a subset of targets. This article will discuss these unexpected context-dependent functions and their implications for the regulation of immune responses. Attention will be also payed to new insights into the role of TTP in physiology and tissue homeostasis.

Foundations of the information science. History and contemporary theories

It presents the result of theoretical research on the history of information science from its theories and concepts. From the systematization of the collected data, a framework has been built in which information science is divided into three major moments: the founding period, in which information science was born as a result of five distinct phenomena (the 1960s); the period of expansion of the problems, with the constitution of six sub-areas (1970s to 1990s); and contemporary perspectives, presented here from the identification of twelve distinct approaches developed in the last twenty years. Next, the six dimensions of the information concept are presented in which the most significant conceptual advances have been made over these decades. Its findings show that the diversity of theories is an enriching factor for the field, but also produces the need for systematization and mapping works.