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Mechanisms of antibiotic resistance

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195268 Year: Pages: 224 DOI: 10.3389/978-2-88919-526-8 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2015-12-10 11:59:06
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Antibiotics represent one of the most successful forms of therapy in medicine. But the efficiency of antibiotics is compromised by the growing number of antibiotic-resistant pathogens. Antibiotic resistance, which is implicated in elevated morbidity and mortality rates as well as in the increased treatment costs, is considered to be one of the major global public health threats (www.who.int/drugresistance/en/) and the magnitude of the problem recently prompted a number of international and national bodies to take actions to protect the public (http://ec.europa.eu/dgs/health_consumer/docs/road-map-amr_en.pdf: http://www.who.int/drugresistance/amr_global_action_plan/en/; http://www.whitehouse.gov/sites/default/files/docs/carb_national_strategy.pdf). Understanding the mechanisms by which bacteria successfully defend themselves against the antibiotic assault represent the main theme of this eBook published as a Research Topic in Frontiers in Microbiology, section of Antimicrobials, Resistance, and Chemotherapy. The articles in the eBook update the reader on various aspects and mechanisms of antibiotic resistance. A better understanding of these mechanisms should facilitate the development of means to potentiate the efficacy and increase the lifespan of antibiotics while minimizing the emergence of antibiotic resistance among pathogens.

Variability and Individual Differences in Early Social Perception and Social Cognition

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198481 Year: Pages: 174 DOI: 10.3389/978-2-88919-848-1 Language: English
Publisher: Frontiers Media SA
Subject: Psychology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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Over the past three decades mounting evidence has suggested that infants’ social perceptual and social cognitive abilities are considerably richer than was once thought. By the end of the second year of life, infants discriminate faces along various social dimensions, attend to and understand others’ goals and intentions, use the emotions of others to guide their learning and behavior, attribute dispositional characteristics to other agents, and make basic social evaluations. What has also become clear is that there is a great deal of variability in infants’ social perception and cognition. A critical, outstanding question concerns the nature and meaning of such variability. The proposed Research Topic welcomes papers addressing cutting-edge questions regarding variability and individual differences in early social perception and social cognition. The goal of these papers is to investigate overarching questions in this domain, which are necessary to move the field forward. Variability in early social perception and social cognition (among other domains) in infancy and early childhood is often attributed to noise, or overlooked in favor of focusing on age-related changes. Yet, recent work suggests that variability in social perceptual and social cognitive tasks reliably inter-relates, and predicts real-world social behaviors. For example, infants’ everyday experience with different face categories predicts individual differences in face processing, infants’ production of goal-directed actions predicts their simultaneous understanding of these actions, and variability in social attention during the second year of life is related to theory of mind during the preschool years. These findings suggest that variability in performance on social perception and social cognition tasks is not merely a nuisance variable, but, rather, may provide the key to addressing significant questions regarding the nature of infants’ social perception and social cognition, and the processes that underlie developmental change. Acknowledging and closely examining and investigating variability in early social perceptual and social cognitive abilities may represent a powerful approach for understanding development in (at least) two ways. First, variability can signal transitional points in the developmental onset of a given ability. Thus, such variability, and the extent to which variability relates to experience and/or other abilities, can be used to test hypotheses regarding mechanisms that underlie developmental changes. Second, variability can represent more enduring individual differences between infants. In this case, critical questions arise regarding the source of individual differences (that is, what factors shape the emergence of individual differences?) and whether such early individual differences contribute to the development of more advanced and sophisticated forms of social cognition and behavior. The goal of this Research Topic will be to encourage researchers to take variability in early social perception and cognition seriously. Papers that give variability center stage, and are aimed at addressing the value of variability for identifying developmental mechanisms, as well as investigating the existence, source, and antecedents of early individual differences in social perception and social cognition are welcomed. Taken together, the contributed papers will provide integral new information to the study of social perception and social cognition over the first three years of life.

Sub- and Supra-Second Timing: Brain, Learning and Development

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198986 Year: Pages: 162 DOI: 10.3389/978-2-88919-898-6 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Psychology
Added to DOAB on : 2016-01-19 14:05:46
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Time perception in the range of milliseconds to a few seconds is essential for many important sensory and perceptual tasks including speech perception, motion perception, motor coordination, and cross-modal interaction. For the brain to be in synchrony with the environment, the physical differences in the speeds of light and sound, as well as stimuli from other modalities such as odors, must be processed and coordinated (Pöppel & Bao 2014; Bao et al., 2015). Time is a subjective feeling that is modulated by emotional states which trigger temporal distortions (temporal dilation vs. contraction) (Wittmann et al., 2014), hence give rise to subjective time that may be different to event time as initially registered in the brain. Recent research suggests that time perception in a multisensory world is subject to prior task experience and shaped by (statistical) learning processes. Humans are active learners. That is, the engagement of the own body in a timing task within a perceptual-action loop will make a noticeable difference in timing performance, as compared to when humans only passively perceive the same perceptual scenario (Bao et al., 2015; Chen & Vroomen, 2013). This Research Topic of “Sub-and Supra-Second Timing: Brain, Learning and Development” has integrated sixteen submissions of novel research on sub- and supra-timing. We have categorized the papers in this topic into the following four themes, from which we can deduce trends of research about multisensory timing in the sub- and supra-second range:Sensory timing, interaction and reliabilityAdaptive representation of time, learning and temporal predictionSensorimotor synchronization, embodiment and coordinationPerspective of psychological moment and temporal organizationOverall, the collections in “Sub-and Supra-Second Timing: Brain, Learning and Development” show some recent trends and debates in multisensory timing research as well as provide a venue to inspire future work in multisensory timing.

Feedforward and Feedback Processes in Vision

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195947 Year: Pages: 151 DOI: 10.3389/978-2-88919-594-7 Language: English
Publisher: Frontiers Media SA
Subject: Psychology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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The visual system consists of hierarchically organized distinct anatomical areas functionally specialized for processing different aspects of a visual object (Felleman & Van Essen, 1991). These visual areas are interconnected through ascending feedforward projections, descending feedback projections, and projections from neural structures at the same hierarchical level (Lamme et al., 1998). Accumulating evidence from anatomical, functional and theoretical studies suggests that these three projections play fundamentally different roles in perception. However, their distinct functional roles in visual processing are still subject to debate (Lamme & Roelfsema, 2000). The focus of this Research Topic is the roles of feedforward and feedback projections in vision. Even though the notions of feedforward, feedback, and reentrant processing are widely accepted, it has been found difficult to distinguish their individual roles on the basis of a single criterion. We welcome empirical contributions, theoretical contributions and reviews that fit into any one (or a combination) of the following domains: 1) their functional roles for perception of specific features of a visual object 2) their contributions to the distinct modes of visual processing (e.g., pre-attentive vs. attentive, conscious vs. unconscious) 3) recent techniques/methodologies to identify distinct functional roles of feedforward and feedback projections and corresponding neural signatures. We believe that the current Research Topic will not only provide recent information about feedforward/feedback processes in vision but also contribute to the understanding fundamental principles of cortical processing in general.

Neuronal Self-Defense: Compensatory Mechanisms in Neurodegenerative Disorders

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889197590 Year: Pages: 190 DOI: 10.3389/978-2-88919-759-0 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-04-07 11:22:02
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Neurodegenerative disorders are characterized by the progressive loss of specific populations of neurons with consequent deterioration of brain's function and dramatic impact on human behavior. At present, there are no effective cures for neurodegenerative diseases. Because unambiguous diagnosis is possible only after manifestation of symptoms, when a large proportion of neurons has been already lost, therapies are necessarily confined to alleviation of symptoms. Development of cures halting the disease course is hampered by our rudimentary understanding of the etiopathology. Most neurodegenerative disorders are sporadic and age-related and - even for those of known genetic origin - the mechanisms influencing disease onset and progression have not been fully characterized. The different diseases, however, share important similarities in the mechanisms responsible for neuronal loss, which is caused by a combination of endogenous and exogenous challenges. Trophic deprivation, oxidative stress, accumulation of abnormal protein aggregates, and bioenergetics defects have been described in most, if not all, neurodegenerative disease. To counterbalance these noxious stimuli cells deploy, at least during the initial pathogenic states, intrinsic neuroprotective responses. These are general compensatory mechanisms, common to several neurodegenerative conditions, which reprogram cellular physiology to overcome stress. Adaptation includes strategies to optimize energetic resources, for instance reduction of rRNA synthesis to repress translation, suppression of transcription, and bioenergetics and metabolic redesign. Additional mechanisms include potentiation of antioxidant capacity, induction of endoplasmic reticulum (ER) stress, and activation of protein quality control systems and autophagy. Ineffective execution of these compensatory strategies severely threatens cellular homeostasis and favors onset of pathology. Therefore, a better understanding of these "buffering" mechanisms and of their interconnections may help to devise more effective therapeutic tools to prolong neuronal survival and activity, independently of the original genetic mutations and stress insults. This Research Topic focuses on the initial compensatory responses protecting against failure of those mechanisms that sustain neuronal survival and activity. The collection intends to summarize the state-of-the-art in this field and to propose novel research contributes, with the ultimate goal of inspiring innovative studies aimed to contrast progression of neurodegenerative diseases.

Antimicrobial Resistance and Virulence Common Mechanisms

Authors: --- ---
Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889451814 Year: Pages: 138 DOI: 10.3389/978-2-88945-181-4 Language: English
Publisher: Frontiers Media SA
Subject: Microbiology --- Science (General)
Added to DOAB on : 2017-08-28 14:01:09
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Multiple relationships exist between antimicrobial resistance and bacterial virulence, and the spread of clones combining multiple antibiotic resistance and a high virulence level is an increasing problem. It was previously described how mutation-driven or horizontally acquired resistance mechanisms can also have effects on virulence. It was also reported that mobile genetic elements often carry both resistance determinants and virulence-modulating genes, which favors the co-selection of both traits. In the present volume, we present a collection of articles which document additional aspects of the interactions between antimicrobial resistance and virulence in bacteria, and describe their potential therapeutic consequences.

Investigation of deformation mechanisms in nanocrystalline metals and alloys by in situ synchrotron X-ray diffraction

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Book Series: Schriftenreihe des Instituts für Angewandte Materialien, Karlsruher Institut für Technologie ISSN: 21929963 ISBN: 9783866449626 Year: Volume: 13 Pages: X, 223 p. DOI: 10.5445/KSP/1000031997 Language: ENGLISH
Publisher: KIT Scientific Publishing
Subject: Technology (General)
Added to DOAB on : 2019-07-30 20:02:01
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In this work, different nanocrystalline metals and alloys were investigated by a synchrotron-based in situ XRD mechanical testing technique in order to investigate the dominant deformation mechanisms. All tested samples show a succession and coexistence of several mechanisms, regardless of grain size, loading condition, or sample geometry. However, the relative shares of the individual mechanisms strongly vary and depend on parameters such as grain size, sample purity, and alloy composition.

Formula Funding of Public Services

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Book Series: Routledge Studies in Business Organizations and Networks ISBN: 9780203013021 9780415362894 9780415511520 9780415654890 9781134229857 9781134229840 9781134229802 Year: DOI: 10.4324/9780203013021 Language: English
Publisher: Taylor & Francis
Subject: Business and Management --- Economics --- Political Science
Added to DOAB on : 2019-11-08 11:21:24
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The use of formulae has become widespread in recent years across most developed countries. In the UK, a conservative estimate is that annually £150 billion of public service expenditure is distributed using formulae, in services such as health care, local government, social security and higher education. This book offers a comprehensive introduction to the theory and practice underlying the use of such formulae as a basis for funding public services. The philosophy, design and economic consequences of funding formulae have become key policy issues worldwide. However, till now, there has been no text which brings together the economic, statistical and political issues underlying formula funding. This key book fills that gap. Written by a leading international expert on the design of funding formulae, this important book includes empirical evidence from a range of countries and will be a valuable resource for all those involved in this field.

Ontogeny and Phylogeny of Brain Barrier Mechanisms

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889198108 Year: Pages: 358 DOI: 10.3389/978-2-88919-810-8 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2016-01-19 14:05:46
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The brain functions within an internal environment that is determined and controlled by morphological structures and cellular mechanisms present at interfaces between the brain and the rest of the body. In vertebrates these interfaces are across cerebral blood vessels (blood-brain barrier) choroid plexuses (blood-cerebrospinal fluid barrier) and pia-arachnoid. There is a CSF-brain barrier in the neuroepithelium lining the ventricular system that is only present in embryos. There is now substantial evidence that many brain barrier mechanisms develop early and that in some cases they are functionally more active and even more specialized compared to adult barriers. Therefore barriers in developing brain should be viewed as adapted appropriately for the growing brain and not, as is still widely believed, immature. Considerable advances in our understanding of these barrier mechanisms have come from studies of the developing brain and invertebrates. A striking aspect, to be highlighted in this special edition, is that many of the molecular mechanisms in these very diverse species are similar despite differences in the cellular composition of the interfaces. This Frontiers Topic comprises articles in three sections: Original studies, Reviews and Myths & Misconceptions. Original articles provide new information on molecular and cellular barrier mechanisms in developing brains of primates, including human embryos (Brøchner et al., Ek et al., Errede et al.), rodents (Bauer et al., Liddelow, Strazielle & Ghersi-Egea, Saunders et al., Whish et al.), chick (Bueno et al.) and zebrafish (Henson et al.) as well as studies in drosophila (Hindle & Bainton, De Salvo et al., Limmer et al.). The Reviews section includes evolutionary perspectives of the blood-brain and blood-CSF barriers (Bueno et al., Bill & Korzh). There are also detailed reviews of the current state of understanding of different interfaces and their functional mechanisms in developing brain (Bauer et al., Strazielle & Gjersi-Egea, Liddelow, Richardson et al., Errede et al., Henson et al., Brøchner et al.) and in invertebrates (Hindle & Bainton, De Salvo et al., Limmer et al). Different aspects of the relationship between properties of the internal environment of the brain and its development are discussed. (Stolp & Molnar, Johansson, Prasongchean et al.). A neglected area, namely barriers over the surface of the brain during development is also covered (Brøchner et al.). Clinically related perspectives on barrier disruption in neonatal stroke are provided by Kratzer et al. and other aspects of dysfunction by Morretti et al. and by Palmeta et al. on the continuing problem of bilirubin toxicity. Progress in this field is hampered by many prevailing myths about barrier function, combined with methodologies that are not always appropriately selected or interpreted. These are covered in the Misconceptions, Myths and Methods section, including historical aspects and discussion of the paracellular pathway, a central dogma of epithelial and endothelial biology (Saunders et al.) and a review of markers used to define brain barrier integrity in development and in pathological conditions (Saunders et al.). Use of inappropriate markers has caused considerable confusion and unreliable interpretation in many published studies. Torbett et al. deal with the complexities of the new field of applying proteomics to understanding blood-brain barrier properties as do Huntley at al. with respect to applying modern high throughput gene expression methods (Huntley et al.). The Editorial summarizes the contributions from all authors. This includes mention of some the main unanswered but answerable questions in the field and what the impediments to progress may be.

Multisensory Perception And Action: Psychophysics, Neural Mechanisms, And Applications

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889193813 Year: Pages: 174 DOI: 10.3389/978-2-88919-381-3 Language: English
Publisher: Frontiers Media SA
Subject: Neurology --- Science (General)
Added to DOAB on : 2015-12-03 13:02:24
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Our senses are not separated. Information received from one sensory modality may be linked with, or distorted by information provided from another modality, such as in the ventriloquism illusion and experiences of crossmodal correspondence. Scientific interest in how we integrate multisensory information and how we interact with a multisensory world has increased dramatically over the last two decades, as evidenced by an exponential growth of relevant studies using behavioral and/or neuro-scientific approaches to investigate multisensory integration and the underlying brain mechanisms. This work has revealed that the brain integrates information across senses in a statistically optimal manner; also, some key multisensory brain areas, such as the superior colliculus, have been identified. However, many questions remain unresolved. For example, at what age do we develop optimal multisensory integration? How does the brain 'know' which stimuli to combine, and which to segregate? What are the principles that govern crossmodal interactions? Does multisensory integration rely solely on the variability of sensory information? Do primary sensory cortices also contribute to multisensory integration? How does multisensory integration influence our sensorimotor interactions? To take stock of the most recent developments, this Research Topic aims to provide a broad scope of research on multisensory perception and action from different perspectives/approaches and disciplines, including behavioral and neuro-sciences, computational/mathematical modeling, and engineering science. Specifically, the Research Topic will focus on the following topics: 1. Functional and behavioral mechanisms of multisensory perception 2. Neural mechanisms of multisensory coding 3. Multisensory perception and sensorimotor interaction 4. Multisensory applications

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