bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local and Remote Influences on the Heat Content of the Labrador Sea: An Adjoint Sensitivity Study
Authors: Jones Daniel C. , Forget Gael , Sinha Bablu , Josey Simon A. , Boland Emma J. D. , Meijers Andrew J. S. , Shuckburgh Emily 
Published: April 2018

AbstractThe Labrador Sea is one of the few regions on the planet where the interior ocean can exchange heat directly with the atmosphere via strong, localized, wintertime convection, with possible implications for the state of North Atlantic climate and global surface warming. Using an observationally constrained ocean adjoint model, we find that annual‐mean Labrador Sea heat content is sensitive to temperature/salinity changes (1) along potential source water pathways (e.g., the subpolar gyre, the North Atlantic Current, the Gulf Stream) and (2) along the West African and European shelves, which are not significant source water regions for the Labrador Sea. The West African coastal/shelf adjustment mechanism, which may be excited by changes in along‐shelf wind stress, involves pressure anomalies that propagate along a coastal waveguide toward Greenland, changing the across‐shelf pressure gradient in the North Atlantic and altering heat convergence in the Labrador Sea. We also find that nonlocal (in space and time) heat fluxes (e.g., in the Irminger Sea, the seas south of Iceland) can have a strong impact on Labrador Sea heat content. Understanding and predicting the state of the Labrador Sea and its potential impacts on North Atlantic climate and global surface warming will require monitoring of oceanic and atmospheric properties at remote sites in the Irminger Sea, the subpolar gyre, and along the West African and European shelf/coast system, among others.
Assessment of Export Efficiency Equations in the Southern Ocean Applied to Satellite‐Based Net Primary Production
Authors: Arteaga Lionel , Haëntjens Nils , Boss Emmanuel , Johnson Kenneth S. , Sarmiento Jorge L. 
Published: April 2018

AbstractCarbon export efficiency (e‐ratio) is defined as the fraction of organic carbon fixed through net primary production (NPP) that is exported out of the surface productive layer of the ocean. Recent observations for the Southern Ocean suggest a negative e‐ratio versus NPP relationship, and a reduced dependency of export efficiency on temperature, different than in the global domain. In this study, we complement information from a passive satellite sensor with novel space‐based lidar observations of ocean particulate backscattering to infer NPP over the entire annual cycle, and estimate Southern Ocean export rates from five different empirical models of export efficiency. Inferred Southern Ocean NPP falls within the range of previous studies, with a mean estimate of 15.8 (± 3.9) Pg C yr−1 for the region south of 30
S during the 2005–2016 period. We find that an export efficiency model that accounts for silica(Si)‐ballasting, which is constrained by observations with a negative e‐ratio versus NPP relationship, shows the best agreement with in situ‐based estimates of annual net community production (annual export of 2.7 ± 0.6 Pg C yr−1 south of 30
S). By contrast, models based on the analysis of global observations with a positive e‐ratio versus NPP relationship predict annually integrated export rates that are ∼ 33% higher than the Si‐dependent model. Our results suggest that accounting for Si‐induced ballasting is important for the estimation of carbon export in the Southern Ocean.
Evaluating the Interplay Between Biophysical Processes and Leaf Area Changes in Land Surface Models
Authors: Forzieri Giovanni , Duveiller Gregory , Georgievski Goran , Li Wei , Robertson Eddy , Kautz Markus , Lawrence Peter , Garcia San Martin Lorea , Anthoni Peter , Ciais Philippe , Pongratz Julia , Sitch Stephen , Wiltshire Andy , Arneth Almut , Cescatti Alessandro 
Published: April 2018

AbstractLand Surface Models (LSMs) are essential to reproduce biophysical processes modulated by vegetation and to predict the future evolution of the land‐climate system. To assess the performance of an ensemble of LSMs (JSBACH, JULES, ORCHIDEE, CLM, and LPJ‐GUESS) a consistent set of land surface energy fluxes and leaf area index (LAI) has been generated. Relationships of interannual variations of modeled surface fluxes and LAI changes have been analyzed at global scale across climatological gradients and compared with those obtained from satellite‐based products. Model‐specific strengths and deficiencies were diagnosed for tree and grass biomes. Results show that the responses of grasses are generally well represented in models with respect to the observed interplay between turbulent fluxes and LAI, increasing the confidence on how the LAI‐dependent partition of net radiation into latent and sensible heat are simulated. On the contrary, modeled forest responses are characterized by systematic bias in the relation between the year‐to‐year variability in LAI and net radiation in cold and temperate climates, ultimately affecting the amount of absorbed radiation due to LAI‐related effects on surface albedo. In addition, for tree biomes, the relationships between LAI and turbulent fluxes appear to contradict the experimental evidences. The dominance of the transpiration‐driven over the observed albedo‐driven effects might suggest that LSMs have the incorrect balance of these two processes. Such mismatches shed light on the limitations of our current understanding and process representation of the vegetation control on the surface energy balance and help to identify critical areas for model improvement.
Animal Venoms: Origin, Diversity and Evolution
Authors: Suranse Vivek , Srikanthan Achyuthan , Sunagar Kartik 
Published: April 2018

AbstractVenomous animals and their venoms have intrigued mankind for millennia. Venoms are complex cocktails of chemically diverse components that disrupt the physiological functioning of the victim to aid the venom‐producing animal in defence and/or feeding. Despite evolving independently on at least 30 occasions in the animal kingdom, venom exhibits remarkable evolutionary convergence, both in composition and biochemical activity. Various factors, including geography, diet, predator pressure, evolutionary arms race and phylogenetic history, underpin the diversification of venoms. Certain venomous animals, particularly snakes, are medically important and are responsible for tens of thousands of permanent loss‐of‐function injuries and deaths in humans every year. At the same time, as venom harbours many bioactive and highly specific components, it has tremendous potential applications in the development of novel lifesaving therapeutics and environment‐friendly agrochemicals. Several wonder drugs based on venom proteins have saved millions of lives worldwide, and many others are in development.Key ConceptsVenom has evolved independently ∼30 times in the animal kingdom to assist the venom‐producing animal in self‐defence and/or prey capture.A remarkable convergence can be observed in the composition and bioactivity of venoms.While most animals modified their salivary glands into venom glands, the duck‐billed platypus and echidna evolved venom glands through the evolutionary tinkering of sweat glands.Cnidarians evolved peculiar cell types to inject venom into their victims, while many hymenopterans have modified their ovipositors for venom injection.The strong influence of positive Darwinian selection has driven the evolutionary diversification of venoms, while the structural integrity is conserved by purifying selection.
Blood Groups: Molecular Genetic Basis
Authors: Avent Neil D 
Published: April 2018

AbstractHuman blood groups are of clinical significance in transfusion medicine and blood group incompatible pregnancy. Blood groups are due to polymorphic structures on human red cells, may arise from carbohydrates or proteins and include most species of proteins found in red cell membranes including transporters, adhesion molecules, structural proteins, complement control proteins, receptors and membrane‐bound enzymes. The molecular background of most clinically significant blood group antigens has been defined at the level of the gene, and there are (as of 2017) 36 blood group systems, with the clinically relevant VEL system being described in 2015 being the most important recent addition. Mass‐scale sequencing projects have revealed yet further complexities in the blood group genes, indicating the possibility for alloimmunisation by these variants. Despite significant advances in SNP genotyping and next‐generation sequencing, routine sequencing of blood donors and patients has not yet materialised.Key ConceptsBlood group antigen expression can be divided into two broad categories: carbohydrate and protein.Protein‐based blood group antigens can be further divided by their functional consequences as membrane transporters, adhesion molecules, receptors/structural components, complement control proteins and membrane‐bound enzymes.The accrual of thousands of complete genome sequences has indicated the occurrence of large numbers of blood group alleles in all blood groups. These may or may not include antigenic polymorphisms that have yet to be identified clinically.Blood group antigen classification and identification of null phenotypes in particular have acted as naturally occurring human knockouts and have revealed the functional significance of the carrier molecules.Blood group genotyping (BGG) has emerged as a useful supplementary analysis for fetuses and patients that are multi‐transfused, e.g. sickle cell patients
Structural Biology of Salt and Drought Tolerance in Plants
Authors: Sánchez‐Barrena María J , Martinez‐Ripoll Martín , Albert Armando 
Published: April 2018

Abstract

Climate disruption is an increasing pressure on food supply worldwide. Consequently, it is required to develop strategies to improve the yield of crops under abiotic stress as plants have to endure novel adverse environmental conditions. Among them, drought and salinity constrain agricultural productivity most dramatically. Many of the plant adaptive responses occur at the cell membrane. There, the communication between those processes that are disrupted as a consequence of the adverse environmental stimuli and those involved in the plant adaptive response is established. The available data show that this communication is achieved by a regulated localisation of different signalling molecules to the vicinity of ion channels and transporters. The structural characterisation of those complexes constitutes a major challenge to understand the mechanism to confer plant resistance to stress and to implement novel biotechnological approaches to ensure food security.

Key Concepts

The understanding at the molecular level of the mechanisms for plant adaptation to drought and salinity helps to implement novel biotechnological approaches to ensure food security.

The cytosolic levels of the phytohormone abscisic acid (ABA) and the Ca
2+
ion (Ca
2+
) act as a molecular switch to plant adaptive response to stress.

Plant cell response to abiotic stress is mediated by supramolecular complexes that are formed in the vicinity or at the cell membrane.

Structural biology has provided the bases for ABA and Ca
2+
roles as they affect the molecular architecture of the signalling complexes regulating plant response.

The structural information can be used to drive a genetic approach and for the identification of small molecules that can be used as new agrochemicals for plant improvement.
Immunisation for the Sake of the ‘Herd’
Authors: Chapman Carolyn R , Caplan Arthur L 
Published: April 2018

Abstract

Individuals who vaccinate directly benefit from the protection it affords them against contracting a specific disease. However, others will often also benefit, as vaccinated individuals cannot transmit the disease. Herd immunity refers to the indirect protection against infectious disease that unvaccinated, or nonimmune, individuals receive as a result of reduced disease transmission due to the presence of vaccinated, or immune, individuals. Herd immunity is important, particularly for individuals who cannot be vaccinated because of age or contraindications, who do not get vaccinated because of refusal, those for whom immunisation is ineffective or for whom immunity has waned due to age. Even when vaccination coverage in a given population is high, certain communities may be at risk of outbreaks if significant numbers of people choose not to vaccinate. Therefore, vaccine hesitancy and vaccine refusal threaten herd immunity. Policymakers can use vaccine mandates to increase vaccination coverage to promote herd immunity.

Key Concepts

Herd immunity refers to the indirect protection against infectious disease that unvaccinated, or nonimmune, individuals receive as a result of reduced disease transmission due to the presence of vaccinated, or immune, individuals.

Herd immunity can provide protection for individuals who cannot be vaccinated because of age or contraindications, who do not get vaccinated because of refusal or other reasons and for those whom vaccination is ineffective.

Even if vaccination coverage in a population is high, vaccines are not perfect, so certain communities may be at risk for outbreaks of infectious disease if the vaccination coverage dips below the herd immunity threshold, such that disease transmission can take place.

Although some individuals may be tempted to forego immunisation, believing they are protected by the vaccination of others around them (herd immunity), nonvaccinated individuals are at higher risk for contracting infectious diseases. For certain diseases, the severity of illness may be increased if contracted at an older age due to delayed exposure (herd severity effect).

Public support of vaccination programmes, such as the National Vaccine Injury Compensation Program in the United States, is justified at least partially because vaccination at the individual level indirectly benefits the health of the population at large.
Sleep and Memory
Authors: Alger Sara E. , Payne Jessica D. 
Published: April 2018

AbstractThere is a wealth of behavioral and physiological evidence that supports a relationship between sleep and memory showing that obtaining sleep actively facilitates the ability to encode new information as well as consolidate and transform material that is newly learned. Sleep, a complex assemblage of electrochemical and physiological brain states, supports the formation and stabilization of many different types of information. In this chapter, we discuss the role of sleep, nocturnal and daytime, in procedural and declarative memory formation, but we focus primarily on neutral and emotionally salient episodic memories. We finish with an extensive consideration of how sleep participates in selectively consolidating salient information and contributes to reorganizing memories to transform them into information that is more flexible for future use.
Visual Cognition and Working Memory
Authors: Woodman Geoffrey F. , Fukuda Keisuke 
Published: April 2018

Abstract
Theories propose that visual working memory (VWM) is the critical representational work space in which we maintain a continuous visual experience, control visual attention, learn new information, and solve problems involving objects and spatial relations. Because VWM has a capacity limit that is equivalent to about three to four objects in the average observer, this memory store represents a bottleneck that must be effectively used and regulated. In this chapter we discuss the current state of knowledge regarding the nature of VWM capacity limits, and how VWM is used to govern learning and interact with the environment. We conclude by discussing a set of future directions that we believe need to be answered for the field to understand the nature of VWM and its relationship to attention and long‐term memory storage.
Timing and Time Perception
Authors: Kononowicz Tadeusz W. , van Rijn Hedderik , Meck Warren H. 
Published: April 2018

AbstractThis chapter reviews recent human and nonhuman animal studies investigating neural signatures of time estimation. Investigation of the neural correlates of time estimation as measured by electrophysiology, electroencephalography, magnetoencephalography, and functional magnetic resonance imaging (fMRI) in humans and other animals has largely been focused on the to‐be‐timed period. Climbing neural activity (e.g., ramping) originating from the supplementary motor area has been implicated as a primary neural marker that coincides with the development of subjective experience of duration. However, it has recently been questioned whether such climbing neural activity directly reflects the neural mechanism(s) underpinning the sense of time. Given that the neural signatures recorded during the to‐be‐timed period are insufficient to explain various aspects of interval timing, this has led to the consideration of processes influencing timingbeforeandafterthe to‐be‐timed period. Because many of these signatures are linked with the supplementary motor area, an extended discussion of the role of this cortical structure in timing and time perception is provided. These neural correlates are interpreted in light of contemporary theories of interval timing, such as the striatal beat frequency model. Future directions for the investigation of the functional and neural mechanisms of interval timing are also discussed.
Visual Object Recognition
Authors: Behrmann Marlene , Vida Mark 
Published: April 2018

AbstractHumans have the remarkable ability to encode and remember thousands of familiar objects in great detail, and yet the psychological and neural mechanisms that contribute to this facility remain elusive. This review considers the recent progress made on this topic, with consideration given to the data gleaned from a host of relevant methodologies. The results of psychophysical and neuroimaging investigations are considered alongside findings that examine object recognition in individuals with deficits in this domain. We also consider the emergence of object recognition skills through behavioral and imaging studies with children. Theoretical accounts and new techniques, including representational (dis)similarity analysis and deep convolution networks, are also considered. As is often the case in such reviews, more questions are raised than answers provided, and the comprehensive understanding of the mechanisms giving rise to visual object recognition remains an alluring challenge to cognitive science.
Depth Perception
Authors: Brenner Eli , Smeets Jeroen B. J. 
Published: April 2018

AbstractThis chapter describes how people judge how far objects are from themselves. Comparing the images in the two eyes and the orientations of the two eyes when looking at the object of interest provides depth information that is based solely on the viewing geometry, but the resolution of such information is limited. Information acquired from cues such as occlusion, motion parallax, and height in the visual field is based on assumptions that need not always be true, such as that objects are isotropic, static, and resting on horizontal surfaces. By combining the many sources of information in a clever manner people obtain quite reliable judgments that are not too sensitive to violations of the assumptions of the individual sources of depth information.
How to Press a Button: Perspectives from the Science of Motor Control
Authors: Mattos Daniela , Frey Scott H. 
Published: April 2018

AbstractPressing a button in response to some stimulus is the most common response in all of experimental psychology. Yet, remarkably little attention has been paid to understanding the surprisingly complex processes that underlie this deceptively simple act. Here, we use the of pressing a response button as a vehicle for discussing some key theoretical and empirical developments in the study of motor control. Our hope is that readers will gain a fresh appreciation of the relevance of this area to investigations of perceptual and cognitive processes that employ motor responses.
Speech Perception
Authors: Eisner Frank , McQueen James M. 
Published: April 2018

AbstractThis chapter reviews the computational processes that are responsible for recognizing word forms in the speech stream. We outline the different stages in a processing hierarchy from the extraction of general acoustic features, through speech‐specific prelexical processes, to the retrieval and selection of lexical representations. We argue that two recurring properties of the system as a whole are abstraction and adaptability. We also present evidence for parallel processing of information on different timescales, more specifically that segmental material in the speech stream (its consonants and vowels) is processed in parallel with suprasegmental material (the prosodic structures of spoken words). We consider evidence from both psycholinguistics and neurobiology wherever possible, and discuss how the two fields are beginning to address common computational problems. The challenge for future research in speech perception will be to build an account that links these computational problems, through functional mechanisms that address them, to neurobiological implementation.
Categorization and Concepts
Authors: Goldstone Robert L. , Kersten Alan , Carvalho Paulo F. 
Published: April 2018

AbstractThe building blocks of human cognition are concepts. What we see, hear, interpret, remember, understand, and talk about is crucially shaped by our concepts. They allow us to communicate, categorize objects and events into inductively powerful groups, organize our world, construct complicated thoughts, and conserve memory resources. Alternative theories have proposed that concepts are represented by rules, prototypical category members, many specific exemplars, and structured theories. We consider empirical evidence bearing on these proposals, which, on balance, recommends pluralism, with different representations implicated in different situations. We consider ways in which concepts shape, and are shaped by, perception and language. Concept‐learning research has important educational applications for helping students learn concepts in an efficient and generalizable manner, and we review what is known about how best to improve concept‐learning outcomes. Finally, we consider future directions for research on concepts and categorization, emphasizing links to other fields, such as object recognition and developmental psychology, and the development and testing of computational models.
Reasoning
Authors: Khemlani Sangeet S. 
Published: April 2018

AbstractReasoning concerns the cognitive processes by which people draw conclusions from the salient, meaningful pieces of information that they comprehend or observe. Reasoning processes are challenging to investigate because both their initiation and their final product (the inference) can be nonverbal and unconscious. This chapter summarizes recent developments in the science of reasoning. It briefly reviews the differences between “core” patterns of inference, that is, deduction, induction, and abduction: Deductions are inferences that are true in those cases in which the premises are true. Inductions concern all other sorts of reasoning. And abductions are special types of inductions that yield explanatory hypotheses. The chapter then addresses three fundamental debates that engage contemporary reasoning researchers. The first addresses how to separate rational from irrational deductions. The second concerns the relation between deduction and induction. And the third focuses on how people create explanations. The chapter concludes by addressing ways of making progress to a general, unified account of higher‐level reasoning.