bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanomechanics of the Cartilage Extracellular Matrix
Authors: Han Lin , Grodzinsky Alan J. , Ortiz Christine
Published: March 2011

Cartilage is a hydrated biomacromolecular fiber composite located at the ends of long bones that enables proper joint lubrication, articulation, loading, and energy dissipation. Degradation of extracellular matrix molecular components and changes in their nanoscale structure greatly influence the macroscale behavior of the tissue and result in dysfunction with age, injury, and diseases such as osteoarthritis. Here, the application of the field of nanomechanics to cartilage is reviewed. Nanomechanics involves the measurement and prediction of nanoscale forces and displacements, intra- and intermolecular interactions, spatially varying mechanical properties, and other mechanical phenomena existing at small length scales. Experimental nanomechanics and theoretical nanomechanics have been applied to cartilage at varying levels of material complexity, e.g., nanoscale properties of intact tissue, the matrix associated with single cells, biomimetic molecular assemblies, and individual extracellular matrix biomolecules (such as aggrecan, collagen, and hyaluronan). These studies have contributed to establishing a fundamental mechanism-based understanding of native and engineered cartilage tissue function, quality, and pathology.
Deep Brain Stimulation for Psychiatric Disorders
Authors: Holtzheimer Paul E. , Mayberg Helen S.
Published: March 2011

Medications, psychotherapy, and other treatments are effective for many patients with psychiatric disorders. However, with currently available interventions, a substantial number of patients experience incomplete resolution of symptoms, and relapse rates are high. In the search for better treatments, increasing interest has focused on focal neuromodulation. This focus has been driven by improved neuroanatomical models of mood, thought, and behavior regulation, as well as by more advanced strategies for directly and focally altering neural activity. Deep brain stimulation (DBS) is one of the most invasive focal neuromodulation techniques available; data have supported its safety and efficacy in a number of movement disorders. Investigators have produced preliminary data on the safety and efficacy of DBS for several psychiatric disorders, as well. In this review, we describe the development and justification for testing DBS for various psychiatric disorders, carefully consider the available clinical data, and briefly discuss potential mechanisms of action.
Reward, Addiction, Withdrawal to Nicotine
Authors: De Biasi Mariella , Dani John A.
Published: March 2011

Nicotine is the principal addictive component that drives continued tobacco use despite users' knowledge of the harmful consequences. The initiation of addiction involves the mesocorticolimbic dopamine system, which contributes to the processing of rewarding sensory stimuli during the overall shaping of successful behaviors. Acting mainly through nicotinic receptors containing the α4 and β2 subunits, often in combination with the α6 subunit, nicotine increases the firing rate and the phasic bursts by midbrain dopamine neurons. Neuroadaptations arise during chronic exposure to nicotine, producing an altered brain condition that requires the continued presence of nicotine to be maintained. When nicotine is removed, a withdrawal syndrome develops. The expression of somatic withdrawal symptoms depends mainly on the α5, α2, and β4 (and likely α3) nicotinic subunits involving the epithalamic habenular complex and its targets. Thus, nicotine taps into diverse neural systems and an array of nicotinic acetylcholine receptor (nAChR) subtypes to influence reward, addiction, and withdrawal.
Olfactory Maps in the Brain
Authors: Murthy Venkatesh N.
Published: March 2011

The responses of neural elements in many sensory areas of the brain vary systematically with their physical position, leading to a topographic representation of the outside world. Sensory representation in the olfactory system has been harder to decipher, in part because it is difficult to find appropriate metrics to characterize odor space and to sample this space densely. Recent experiments have shown that the arrangement of glomeruli, the elementary units of processing, is relatively invariant across individuals in a species, yet it is flexible enough to accommodate new sensors that might be added. Evidence supports the existence of coarse spatial domains carved out on a genetic or functional basis, but a systematic organization of odor responses or neural circuits on a local scale is not evident. Experiments and theory that relate the properties of odorant receptors to the detailed wiring diagram of the downstream olfactory circuits and to behaviors they trigger may reveal the design principles that have emerged during evolution.
Recovery of Locomotion After Spinal Cord Injury: Some Facts and Mechanisms
Authors: Rossignol Serge , Frigon Alain
Published: March 2011

After spinal cord injury (SCI), various sensorimotor functions can recover, ranging from simple spinal reflexes to more elaborate motor patterns, such as locomotion. Locomotor recovery after complete spinalization (complete SCI) must depend on the presence of spinal circuitry capable of generating the complex sequential activation of various leg muscles. This is achieved by an intrinsic spinal circuitry, termed the central pattern generator (CPG), working in conjunction with sensory feedback from the legs. After SCI, different changes in cellular and circuit properties occur spontaneously and can be promoted by pharmacological, electrical, or rehabilitation strategies. After partial SCI, hindlimb locomotor recovery can result from regeneration or sprouting of spared pathways, but also from mechanisms observed after complete SCI, namely changes within the intrinsic spinal circuitry and sensory inputs.
Three-Dimensional Transformations for Goal-Directed Action
Authors: Crawford J. Douglas , Henriques Denise Y.P. , Medendorp W. Pieter
Published: March 2011

Much of the central nervous system is involved in visuomotor transformations for goal-directed gaze and reach movements. These transformations are often described in terms of stimulus location, gaze fixation, and reach endpoints, as viewed through the lens of translational geometry. Here, we argue that the intrinsic (primarily rotational) 3-D geometry of the eye-head-reach systems determines the spatial relationship between extrinsic goals and effector commands, and therefore the required transformations. This approach provides a common theoretical framework for understanding both gaze and reach control. Combined with an assessment of the behavioral, neurophysiological, imaging, and neuropsychological literature, this framework leads us to conclude that (a) the internal representation and updating of visual goals are dominated by gaze-centered mechanisms, but (b) these representations must then be transformed as a function of eye and head orientation signals into effector-specific 3-D movement commands.
Transcriptional Control of the Terminal Fate of Monoaminergic Neurons
Authors: Flames Nuria , Hobert Oliver
Published: March 2011

Monoaminergic neurons are critical functional components of all nervous systems across phylogeny. The terminally differentiated state of individual types of monoaminergic neurons is defined by the coordinated expression of a battery of genes that instructs the synthesis and transport of specific monoamines, such as serotonin or dopamine. Dysfunction or deregulation of several of these enzymes and transporter system has been proposed to be the underlying basis of several pathological conditions. We review here the state of knowledge of the nature of the transcriptional regulatory programs that control the expression of what we term monoaminergic gene batteries (enzymes and transporters for specific monoamines) and thereby define the terminally differentiated state of monoaminergic neurons. We review several case studies in vertebrate and invertebrate model systems and propose that the coordinated expression of the genes that define individual monoaminergic cell types may be brought about by transcriptional coregulatory strategies.
How Is the Olfactory Map Formed and Interpreted in the Mammalian Brain?
Authors: Mori Kensaku , Sakano Hitoshi
Published: March 2011

Odor signals received by odorant receptors (ORs) expressed by olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) are represented as an odor map in the olfactory bulb (OB). In the mouse, there are ∼1,000 different OR species, and each OSN expresses only one functional OR gene in a monoallelic manner. Furthermore, OSN axons expressing the same type of OR converge on a specific target site in the OB, forming a glomerular structure. Because each glomerulus represents a single OR species, and a single odorant can interact with multiple OR species, odor signals received in the OE are converted into a topographic map of multiple glomeruli activated with varying magnitudes. Here we review recent progress in the study of the mammalian olfactory system, focusing on the formation of the olfactory map and the transmission of topographical information in the OB to the olfactory cortex to elicit various behaviors.
Neutrino Mass in Cosmology: Status and Prospects
Authors: Wong Yvonne Y.Y.
Published: March 2011

I give an overview of the effects of neutrino masses in cosmology, focusing on the role they play in the evolution of cosmological perturbations. I discuss how recent observations of the cosmic microwave background anisotropies and the large-scale matter distribution can probe neutrino masses with greater precision than current laboratory experiments. I describe several new techniques that will be used to probe cosmology in the future, as well as recent advances in the computation of the nonlinear matter-power spectrum and related observables.
Symmetry Tests in Nuclear Beta Decay
Authors: Severijns Nathal , Naviliat-Cuncic Oscar
Published: March 2011

Precision measurements in nuclear β decay provide sensitive means to test the structure of the standard electroweak model; they also allow the determination of fundamental properties in processes that involve the lightest quarks. The primary aim of such tests is to find deviations from the Standard Model predictions that may indicate new physics. We review here the status of precision measurements in nuclear β decay, including selected experiments in neutron decay, and discuss recent results and developments. Among these developments are the consideration of nuclear mirror transitions as a new window in which to test the unitarity condition of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix, measurements of angular correlation observables to search for exotic couplings, and tests of discrete symmetries.
Observation of Single Top Quark Production
Authors: Heinson Ann , Junk Thomas R.
Published: March 2011

The field of experimental particle physics has become more sophisticated over time, as fewer, larger experimental collaborations search for small signals in samples with large components of background. The search for and the observation of electroweak single top quark production by the CDF and DØ Collaborations at Fermilab's Tevatron collider are an example of an elaborate effort to measure the rate of a very rare process in the presence of large backgrounds and to learn about the properties of the top quark's weak interaction. We present the techniques used to make this groundbreaking measurement and the interpretation of the results in the context of the Standard Model.
Particle Physics Outreach to Secondary Education
Authors: Bardeen Marjorie G. , Erik Johansson K. , Jean Young M.
Published: March 2011

This review summarizes exemplary secondary education and outreach programs of the particle physics community. We examine programs from the following areas: research experiences, high-energy physics data for students, informal learning for students, instructional resources, and professional development. We report findings about these programs' impact on students and teachers and provide suggestions for practices that create effective programs from those findings. We also include some methods for assessing programs.
Neutral Pion Decay
Authors: Miskimen R.
Published: March 2011

The study of π0 decay has played an important role in the development of particle physics: The π0→γγ decay provides key insights into the anomaly sector of quantum chromodynamics. In this review, the historical progression of π0 discovery, lifetime measurements, and theory are presented. A new measurement of the π0 radiative width via the Primakoff effect has been made at JLab. The result, Γ(π0→γγ)=7.82±0.14(stat.)±0.17(syst.) eV, is a factor of 2.1 more precise than the currently accepted value, and it is in agreement with the chiral anomaly prediction and with next-to-leading-order chiral perturbation theory calculations. Primakoff experiments at higher energies to measure the η and η′ radiative widths are also discussed.
The Large Hadron Collider
Authors: Evans Lyndon
Published: March 2011

The Large Hadron Collider (LHC) is the most complex instrument ever built for particle physics research. It will, for the first time, provide access to the TeV-energy scale. Numerous technological innovations are necessary to achieve this goal. For example, two counterrotating proton beams are guided and focused by superconducting magnets whose novel two-in-one structure saves cost and allowed the machine to be installed in an existing tunnel. The very high (>8-T) field in the dipoles can be achieved only by cooling them below the transition temperature of liquid helium to the superfluid state. More than 80 tons of superfluid helium are needed to cool the whole machine. So far, the LHC has behaved reliably and predictably. Single-bunch currents 30% above the design value have been achieved, and the luminosity has increased by five orders of magnitude. In this review, I briefly describe the design principles of the major systems and discuss some initial results.
The Primordial Lithium Problem
Authors: Fields Brian D.
Published: March 2011

Big bang nucleosynthesis (BBN) theory, together with the precise WMAP cosmic baryon density, makes tight predictions for the abundances of the lightest elements. Deuterium and 4He measurements agree well with expectations, but 7Li observations lie below the BBN+WMAP prediction by a factor of three to four. This 4–5-σ mismatch constitutes the so-called cosmic lithium problem; disparate solutions are possible. First, astrophysical systematics in the observations could exist but are increasingly constrained. Second, nuclear physics experiments provide a wealth of well-measured cross-section data, but 7Be destruction could be enhanced by unknown or poorly measured resonances. Third, physics beyond the Standard Model could alter the 7Li abundance, although deuterium and 4He must remain unperturbed. In this review, we discuss such scenarios, highlighting decaying supersymmetric particles and time-varying fundamental constants. Present and planned experiments could reveal which (if any) of these proposed solutions is correct.
Knockout Mouse Models of Iron Homeostasis
Authors: Fleming Robert E. , Feng Qi , Britton Robert S.
Published: March 2011

Murine models have made valuable contributions to our understanding of iron metabolism. Investigation of mice with inherited forms of anemia has led to the discovery of novel proteins involved in iron homeostasis. A growing number of murine models are being developed to investigate mitochondrial iron metabolism. Mouse strains are available for the major forms of hereditary hemochromatosis. Findings in murine models support the concept that the pathogenesis of nearly all forms of hereditary hemochromatosis involves inappropriately low expression of hepcidin. The availability of mice with floxed iron-related genes allows the study of the in vivo consequences of cell-selective deletion of these genes.
Cytochrome P450s in the Regulation of Cellular Retinoic Acid Metabolism
Authors: Catharine Ross A. , Zolfaghari Reza
Published: March 2011

The active metabolite of vitamin A, retinoic acid (RA), is a powerful regulator of gene transcription. RA is also a therapeutic drug. The oxidative metabolism of RA by certain members of the cytochrome P450 (CYP) superfamily helps to maintain tissue RA concentrations within appropriate bounds. The CYP26 family—CYP26A1, CYP26B1, and CYP26C1—is distinguished by being both regulated by and active toward all-trans-RA (at-RA) while being expressed in different tissue-specific patterns. The CYP26A1 gene is regulated by multiple RA response elements. CYP26A1 is essential for embryonic development, whereas CYP26B1 is essential for postnatal survival as well as germ cell development. Enzyme kinetic studies have demonstrated that several CYP proteins are capable of metabolizing at-RA; however, it is likely that CYP26A1 plays a major role in RA clearance. Thus, pharmacological approaches to limiting the activity of CYP26 enzymes may extend the half-life of RA and could be useful clinically in the future.
Merkel Cell Carcinoma: A Virus-Induced Human Cancer
Authors: Chang Yuan , Moore Patrick S.
Published: March 2011

Merkel cell polyomavirus (MCV) is the first polyomavirus directly linked to human cancer, and its recent discovery helps to explain many of the enigmatic features of Merkel cell carcinoma (MCC). MCV is clonally integrated into MCC tumor cells, which then require continued MCV oncoprotein expression to survive. The integrated viral genomes have a tumor-specific pattern of tumor antigen gene mutation that incapacitates viral DNA replication. This human cancer virus provides a new model in which a common, mostly harmless member of the human viral flora can initiate cancer if it acquires a precise set of mutations in a host with specific susceptibility factors, such as age and immune suppression. Identification of this tumor virus has led to new opportunities for early diagnosis and targeted treatment of MCC.
Molecular Pathogenesis of Ewing Sarcoma: New Therapeutic and Transcriptional Targets
Authors: Lessnick Stephen L. , Ladanyi Marc
Published: March 2011

Approximately one-third of sarcomas contain specific translocations. Ewing sarcoma is the prototypical member of this group of sarcomas; it was the first to be recognized pathologically as a singular entity and to have its signature translocation defined cytogenetically, which led to the identification of its key driver alteration, the EWS-FLI1 gene fusion that encodes this aberrant, chimeric transcription factor. We review recent progress in selected areas of Ewing sarcoma research, including the application of genome-wide chromatin immunoprecipitation analyses, to provide a comprehensive view of the EWS-FLI1 target gene repertoire, the identification of EWS-FLI1 target genes that may also point to therapeutically targetable pathways, and data from model systems as they relate to the elusive cell of origin of Ewing sarcoma and its possible similarities to mesenchymal stem cells.
The Th17 Pathway and Inflammatory Diseases of the Intestines, Lungs, and Skin
Authors: Weaver Casey T. , Elson Charles O. , Fouser Lynette A. , Kolls Jay K.
Published: March 2011

The recent discovery of a new CD4+T cell subset, Th17, has transformed our understanding of the pathogenetic basis of an increasing number of chronic immune-mediated diseases. Particularly in tissues that interface with the microbial environment—such as the intestinal and respiratory tracts and the skin—where most of the Th17 cells in the body reside, dysregulated immunity to self (or the extended self, the diverse microbiota that normally colonize these tissues) can result in chronic inflammatory disease. In this review, we focus on recent advances in the biology of the Th17 pathway and on genome-wide association studies that implicate this immune pathway in human disease involving these tissues.
Molecular Pathophysiology of Myelodysplastic Syndromes
Authors: Lindsley R. Coleman , Ebert Benjamin L.
Published: March 2011

The clinicopathologic heterogeneity of myelodysplastic syndromes (MDS) is driven by diverse, somatically acquired genetic abnormalities. Recent technological advances have enabled the identification of many new mutations, which have implicated novel pathways in MDS pathogenesis, including RNA splicing and epigenetic regulation of gene expression. Molecular abnormalities, either somatic point mutations or chromosomal lesions, can be identified in the vast majority of MDS cases and underlie specific disease phenotypes. As the full array of molecular abnormalities is characterized, genetic variables are likely to complement standard morphologic evaluation in future MDS classification schemes and risk models.
Skeletal Muscle Degenerative Diseases and Strategies for Therapeutic Muscle Repair
Authors: Tabebordbar Mohammadsharif , Wang Eric T. , Wagers Amy J.
Published: March 2011

Skeletal muscle is a highly specialized, postmitotic tissue that must withstand chronic mechanical and physiological stress throughout life to maintain proper contractile function. Muscle damage or disease leads to progressive weakness and disability, and manifests in more than 100 different human disorders. Current therapies to treat muscle degenerative diseases are limited mostly to the amelioration of symptoms, although promising new therapeutic directions are emerging. In this review, we discuss the pathological basis for the most common muscle degenerative diseases and highlight new and encouraging experimental and clinical opportunities to prevent or reverse these afflictions.
Molecular Mechanisms of Fragile X Syndrome: A Twenty-Year Perspective
Authors: Santoro Michael R. , Bray Steven M. , Warren Stephen T.
Published: March 2011

Fragile X syndrome (FXS) is a common form of inherited intellectual disability and is one of the leading known causes of autism. The mutation responsible for FXS is a large expansion of the trinucleotide CGG repeat in the 5′ untranslated region of the X-linked gene FMR1. This expansion leads to DNA methylation of FMR1 and to transcriptional silencing, which results in the absence of the gene product, FMRP, a selective messenger RNA (mRNA)-binding protein that regulates the translation of a subset of dendritic mRNAs. FMRP is critical for mGluR (metabotropic glutamate receptor)-dependent long-term depression, as well as for other forms of synaptic plasticity; its absence causes excessive and persistent protein synthesis in postsynaptic dendrites and dysregulated synaptic function. Studies continue to refine our understanding of FMRP's role in synaptic plasticity and to uncover new functions of this protein, which have illuminated therapeutic approaches for FXS.
The Intestinal Absorption of Folates
Authors: Visentin Michele , Diop-Bove Ndeye , Zhao Rongbao , Goldman I. David
Published: March 2011

The properties of intestinal folate absorption were documented decades ago. However, it was only recently that the proton-coupled folate transporter (PCFT) was identified and its critical role in folate transport across the apical brush-border membrane of the proximal small intestine established by the loss-of-function mutations identified in the PCFT gene in subjects with hereditary folate malabsorption and, more recently, by the Pcft-null mouse. This article reviews the current understanding of the properties of PCFT-mediated transport and how they differ from those of the reduced folate carrier. Other processes that contribute to the transport of folates across the enterocyte, along with the contribution of the enterohepatic circulation, are considered. Important unresolved issues are addressed, including the mechanism of intestinal folate absorption in the absence of PCFT and regulation of PCFT gene expression. The impact of a variety of ions, organic molecules, and drugs on PCFT-mediated folate transport is described.
The Calcium-Sensing Receptor Beyond Extracellular Calcium Homeostasis: Conception, Development, Adult Physiology, and Disease
Authors: Riccardi Daniela , Kemp Paul J.
Published: March 2011

The extracellular calcium-sensing receptor (CaSR) is the first identified G protein–coupled receptor to be activated by an ion, extracellular calcium (Ca2+). Since the identification of the CaSR in 1993, genetic mutations in the CaSR gene, and murine models in which CaSR expression has been manipulated, have clearly demonstrated the importance of this receptor in the maintenance of stable, free, ionized Ca2+concentration in the extracellular fluids. These functions have been extensively reviewed elsewhere. However, the distribution pattern and expression of the CaSR in lower vertebrates strongly suggest that the CaSR must play a role that is independent of mineral cation metabolism. This review addresses the involvement of the CaSR in nutrient sensing; its putative and demonstrated functions during conception, embryonic development, and birth; and its contributions to adult physiology and disease, with reference to CaSR-based therapeutics. Recent ongoing developments concerning the role of the CaSR in stem cell differentiation are also reviewed.
Nuclear Sphingolipid Metabolism
Authors: Lucki Natasha C. , Sewer Marion B.
Published: March 2011

Nuclear lipid metabolism is implicated in various processes, including transcription, splicing, and DNA repair. Sphingolipids play roles in numerous cellular functions, and an emerging body of literature has identified roles for these lipid mediators in distinct nuclear processes. Different sphingolipid species are localized in various subnuclear domains, including chromatin, the nuclear matrix, and the nuclear envelope, where sphingolipids exert specific regulatory and structural functions. Sphingomyelin, the most abundant nuclear sphingolipid, plays both structural and regulatory roles in chromatin assembly and dynamics in addition to being an integral component of the nuclear matrix. Sphingosine-1-phosphate modulates histone acetylation, sphingosine is a ligand for steroidogenic factor 1, and nuclear accumulation of ceramide has been implicated in apoptosis. Finally, nuclear membrane–associated ganglioside GM1 plays a pivotal role in Ca2+ homeostasis. This review highlights research on the factors that control nuclear sphingolipid metabolism and summarizes the roles of these lipids in various nuclear processes.
Stop the Flow: A Paradigm for Cell Signaling Mediated by Reactive Oxygen Species in the Pulmonary Endothelium
Authors: Browning Elizabeth A. , Chatterjee Shampa , Fisher Aron B.
Published: March 2011

The lung endothelium is exposed to mechanical stimuli through shear stress arising from blood flow and responds to altered shear by activation of NADPH (NOX2) to generate reactive oxygen species (ROS). This review describes the pathway for NOX2 activation and the downstream ROS-mediated signaling events on the basis of studies of isolated lungs and flow-adapted endothelial cells in vitro that are subjected to acute flow cessation (ischemia). Altered mechanical stress is detected by a cell-associated complex involving caveolae and other membrane proteins that results in endothelial cell membrane depolarization and then the activation of specific kinases that lead to the assembly of NOX2 components. ROS generated by this enzyme amplify the mechanosignal within the endothelial cell to regulate activation and/or synthesis of proteins that participate in cell growth, proliferation, differentiation, apoptosis, and vascular remodeling. These responses indicate an important role for NOX2-derived ROS associated with mechanotransduction in promoting vascular homeostasis.
Sperm-Egg Interaction
Authors: Evans Janice P.
Published: March 2011

A crucial step of fertilization is the sperm-egg interaction that allows the two gametes to fuse and create the zygote. In the mouse, CD9 on the egg and IZUMO1 on the sperm stand out as critical players, as Cd9−/−and Izumo1−/−mice are healthy but infertile or severely subfertile due to defective sperm-egg interaction. Moreover, work on several nonmammalian organisms has identified some of the most intriguing candidates implicated in sperm-egg interaction. Understanding of gamete membrane interactions is advancing through characterization of in vivo and in vitro fertilization phenotypes, including insights from less robust phenotypes that highlight potential supporting (albeit not absolutely essential) players. An emerging theme is that there are varied roles for gamete molecules that participate in sperm-egg interactions. Such roles include not only functioning as fusogens, or as adhesion molecules for the opposite gamete, but also functioning through interactions in cis with other proteins to regulate membrane order and functionality.
Distributive Politics Around the World
Authors: Golden Miriam , Min Brian
Published: March 2011

We inventory more than 150 studies of distributive politics in more than three dozen countries other than the United States. We organize existing studies under two theories: theories of democratic accountability and theories of government responsiveness. Studies that concern democratic accountability conceptualize distributive allocations as attempts by politicians to protect themselves electorally by targeting specific groups of voters. We identify four subsets: (a) studies of whether politicians target goods to core or swing voters; (b) studies of general political favoritism in targeting government goods; (c) studies of whether goods are disbursed according to the electoral cycle; and (d) studies of whether elected officials gain votes from the disbursement of government goods. We illustrate each with examples from the literature. We then discuss distributive politics as responsiveness to the median voter. This perspective entails a focus on the redistributive consequences of government policy and investigates whether special interests capture a disproportionate share of goods coming from government. To illustrate the utility of both perspectives, we analyze original data on electricity provision in India's largest state.
Intelligence
Authors: Deary Ian J.
Published: March 2011

Individual differences in human intelligence are of interest to a wide range of psychologists and to many people outside the discipline. This overview of contributions to intelligence research covers the first decade of the twenty-first century. There is a survey of some of the major books that appeared since 2000, at different levels of expertise and from different points of view. Contributions to the phenotype of intelligence differences are discussed, as well as some contributions to causes and consequences of intelligence differences. The major causal issues covered concern the environment and genetics, and how intelligence differences are being mapped to brain differences. The major outcomes discussed are health, education, and socioeconomic status. Aging and intelligence are discussed, as are sex differences in intelligence and whether twins and singletons differ in intelligence. More generally, the degree to which intelligence has become a part of broader research in neuroscience, health, and social science is discussed.
Child Development in the Context of Disaster, War, and Terrorism: Pathways of Risk and Resilience
Authors: Masten Ann S. , Narayan Angela J.
Published: March 2011

This review highlights progress over the past decade in research on the effects of mass trauma experiences on children and youth, focusing on natural disasters, war, and terrorism. Conceptual advances are reviewed in terms of prevailing risk and resilience frameworks that guide basic and translational research. Recent evidence on common components of these models is evaluated, including dose effects, mediators and moderators, and the individual or contextual differences that predict risk or resilience. New research horizons with profound implications for health and well-being are discussed, particularly in relation to plausible models for biological embedding of extreme stress. Strong consistencies are noted in this literature, suggesting guidelines for disaster preparedness and response. At the same time, there is a notable shortage of evidence on effective interventions for child and youth victims. Practical and theory-informative research on strategies to protect children and youth victims and promote their resilience is a global priority.
Human Infancy...and the Rest of the Lifespan
Authors: Bornstein Marc H.
Published: March 2011

Human infancy has been studied as a platform for hypothesis and theory testing, as a major physiological and psychological adjustment, as an object of adults' effects as well as a source of effects on adults, for its comparative value, as a stage of life, and as a setting point for the life course. Following an orientation to infancy studies, including previous reviews and a discussion of the special challenges infants pose to research, this article focuses on infancy as a foundation and catalyst of human development in the balance of the life course. Studies of stability and prediction from infancy illustrate the depth and complexity of modern research on infants and provide a long-awaited reply to key philosophical and practical questions about the meaningfulness and significance of infancy.
Rapid Automatized Naming (RAN) and Reading Fluency: Implications for Understanding and Treatment of Reading Disabilities
Authors: Norton Elizabeth S. , Wolf Maryanne
Published: March 2011

Fluent reading depends on a complex set of cognitive processes that must work together in perfect concert. Rapid automatized naming (RAN) tasks provide insight into this system, acting as a microcosm of the processes involved in reading. In this review, we examine both RAN and reading fluency and how each has shaped our understanding of reading disabilities. We explore the research that led to our current understanding of the relationships between RAN and reading and what makes RAN unique as a cognitive measure. We explore how the automaticity that supports RAN affects reading across development, reading abilities, and languages, and the biological bases of these processes. Finally, we bring these converging areas of knowledge together by examining what the collective studies of RAN and reading fluency contribute to our goals of creating optimal assessments and interventions that help every child become a fluent, comprehending reader.
The Multiple Origins of Complex Multicellularity
Authors: Knoll Andrew H.
Published: March 2011

Simple multicellularity has evolved numerous times within the Eukarya, but complex multicellular organisms belong to only six clades: animals, embryophytic land plants, florideophyte red algae, laminarialean brown algae, and two groups of fungi. Phylogeny and genomics suggest a generalized trajectory for the evolution of complex multicellularity, beginning with the co-optation of existing genes for adhesion. Molecular channels to facilitate cell-cell transfer of nutrients and signaling molecules appear to be critical, as this trait occurs in all complex multicellular organisms but few others. Proliferation of gene families for transcription factors and cell signals accompany the key functional innovation of complex multicellular clades: differentiated cells and tissues for the bulk transport of oxygen, nutrients, and molecular signals that enable organisms to circumvent the physical limitations of diffusion. The fossil records of animals and plants document key stages of this trajectory.
Housing Bubbles: A Survey
Authors: Mayer Christopher
Published: March 2011

The past 25 years have represented two periods of extreme movements in U.S. and global house prices that appear to be much larger than can be easily explained by changes in fundamentals. These episodes spurred research on housing bubbles that focused attention on the role of outsized expectations in excessive house price appreciation. By contrast, some economists pointed to alternative explanations for excess volatility, including liquidity constraints, lending cycles, search externalities, and zoning delays. Empirical work supports the role of these factors in explaining at least some of the cyclical variation of house prices and inventories of homes for sale. Existing research does not yet provide a crisp definition of a housing bubble nor does it allow researchers to predict where or when bubbles can occur.
Studying Discrimination: Fundamental Challenges and Recent Progress
Authors: Charles Kerwin Kofi , Guryan Jonathan
Published: March 2011

We discuss research on discrimination against blacks and other racial minorities in labor market outcomes, highlighting fundamental challenges faced by empirical work in this area. Specifically, for work devoted to measuring whether and how much discrimination exists, we discuss how the absence of relevant data, the potential noncomparability of blacks and whites, and various conceptual concerns peculiar to race may frustrate or render impossible the application of empirical methods used in other areas of study. For work seeking to arbitrate empirically between the two main alternative theoretical explanations for such discrimination as it exists, we distinguish between indirect analyses, which do not directly study the variation in prejudice or the variation in information, the mechanisms at the heart of the two types of models we review, and direct analyses, which are more recent and much less common. We highlight problems with both approaches. Throughout, we discuss recent work, which, the various challenges notwithstanding, permits tentative conclusions about discrimination. We conclude by pointing to areas that might be fruitful avenues for future investigation.
Political Economy Models of Elections
Authors: Dewan Torun , Shepsle Kenneth A.
Published: March 2011

We review a large formal literature on economic models of voting and electoral politics. We discuss two broad classes of model: those focusing on preference aggregation and those that look at elections as mechanisms of information aggregation. We also explore the role of elections in situations of asymmetric information, where politicians take hidden actions or are otherwise better informed about policy than voters are, and examine the role of elections in selection and as incentive mechanisms. In the section on models of preference aggregation, we focus on the themes of exogenous candidacy, policy commitment, and the role of valence attributes. For information aggregation, we analyze how different aspects of the institutional environment affect aggregation, focusing on the structure of elections—whether simultaneous or sequential—and the number of choices, as well as the motivations of voters. Finally, in considering models of asymmetric information, we describe how these models shed new light on incumbency effects, campaign spending, and the policy choices of politicians.
Fear Extinction as a Model for Translational Neuroscience: Ten Years of Progress
Authors: Milad Mohammed R. , Quirk Gregory J.
Published: March 2011

The psychology of extinction has been studied for decades. Approximately 10 years ago, however, there began a concerted effort to understand the neural circuits of extinction of fear conditioning, in both animals and humans. Progress during this period has been facilitated by a high degree of coordination between rodent and human researchers examining fear extinction. Here we review the major advances and highlight new approaches to understanding and exploiting fear extinction. Research in fear extinction could serve as a model for translational research in other areas of behavioral neuroscience.
Social and Economic Returns to College Education in the United States
Authors: Hout Michael
Published: March 2011

Education correlates strongly with most important social and economic outcomes such as economic success, health, family stability, and social connections. Theories of stratification and selection created doubts about whether education actually caused good things to happen. Because schools and colleges select who continues and who does not, it was easy to imagine that education added little of substance. Evidence now tips the balance away from bias and selection and in favor of substance. Investments in education pay off for individuals in many ways. The size of the direct effect of education varies among individuals and demographic groups. Education affects individuals and groups who are less likely to pursue a college education more than traditional college students. A smaller literature on social returns to education indicates that communities, states, and nations also benefit from increased education of their populations; some estimates imply that the social returns exceed the private returns.
Political Repression: Iron Fists, Velvet Gloves, and Diffuse Control
Authors: Earl Jennifer
Published: March 2011

This article reviews research on political repression by social movement scholars. Four topics are discussed: (a) debates over the conceptualization of repression, the breadth of the concept, whether distinctions within the concept are productive and/or forms of repression are directly comparable, and the relationship between repression and political opportunities; (b) recent research on different types of repression, particularly protest policing; (c) an evaluation of research on different explanations of repression; and (d) an evaluation of research on the consequences of repression. Attention is also paid to areas where future research effort might be most productively spent, including identifying substantial gaps where more research is needed, where important debates exist that need research to push toward their resolution, where robust results exist but could be furthered by refinements, and where a more inclusive conceptualization of repression may link the study of repression to other significant literatures.
Angularis oculi vein blood flow modulates the magnitude but not the control of selective brain cooling in sheep
Authors: Fuller Andrea , Hetem Robyn S. , Meyer Leith C. R. , Maloney Shane K.
Published: March 2011

To investigate the role of the angularis oculi vein (AOV) in selective brain cooling (SBC), we measured brain and carotid blood temperatures in six adult female Dorper sheep. Halfway through the study, a section of the AOV, just caudal to its junction with the dorsal nasal vein, was extirpated on both sides. Before and after AOV surgery, the sheep were housed outdoors at 21–22°C and were exposed in a climatic chamber to daytime heat (40°C) and water deprivation for 5 days. In sheep outdoors, SBC was significantly lower after the AOV had been cut, with its 24-h mean reduced from 0.25 to 0.01°C ( t5 = 3.06, P = 0.03). Carotid blood temperature also was lower (by 0.28°C) at all times of day ( t5 = 3.68, P = 0.01), but the pattern of brain temperature was unchanged. The mean threshold temperature for SBC was not different before (38.85 ± 0.28°C) and after (38.85 ± 0.39°C) AOV surgery ( t5 =0.00, P = 1.00), but above the threshold, SBC magnitude was about twofold less after surgery. SBC after AOV surgery also was less during heat exposure and water deprivation. However, SBC increased progressively by the same magnitude (0.4°C) over the period of water deprivation, and return of drinking water led to rapid cessation of SBC in sheep before and after AOV surgery. We conclude that the AOV is not the only conduit for venous drainage contributing to SBC in sheep and that, contrary to widely held opinion, control of SBC does not involve changes in the vasomotor state of the AOV.
Angiotensin type 1 receptor modulates macrophage polarization and renal injury in obesity
Authors: Ma Li-Jun , Corsa Bridgette A. , Zhou Jun , Yang HaiChun , Li HaiJing , Tang Yi-Wei , Babaev Vladimir R. , Major Amy S. , Linton MacRae F. , Fazio Sergio , Hunley Tracy E. , Kon Valentina , Fogo Agnes B.
Published: March 2011

The mechanisms for increased risk of chronic kidney disease (CKD) in obesity remain unclear. The renin-angiotensin system is implicated in the pathogenesis of both adiposity and CKD. We investigated whether the angiotensin type 1 (AT1) receptor, composed of dominant AT1a and less expressed AT1b in wild-type (WT) mice, modulates development and progression of kidney injury in a high-fat diet (HFD)-induced obesity model. WT mice had increased body weight, body fat, and insulin levels and decreased adiponectin levels after 24 wk of a high-fat diet. Identically fed AT1a knockout (AT1aKO) mice gained weight similarly to WT mice, but had lower body fat and higher plasma cholesterol. Both obese AT1aKO and obese WT mice had increased visceral fat and kidney macrophage infiltration, with more proinflammatory M1 macrophage markers as well as increased mesangial expansion and tubular vacuolization, compared with lean mice. These abnormalities were heightened in the obese AT1aKO mice, with downregulated M2 macrophage markers and increased macrophage AT1b receptor. Treatment with an AT1 receptor blocker, which affects both AT1a and AT1b, abolished renal macrophage infiltration with inhibition of renal M1 and upregulation of M2 macrophage markers in obese WT mice. Our data suggest obesity accelerates kidney injury, linked to augmented inflammation in adipose and kidney tissues and a proinflammatory shift in macrophage and M1/M2 balance.
Voltage-Sensing Phosphatase: Its Molecular Relationship With PTEN
Authors: Okamura Yasushi , Dixon Jack E.
Published: March 2011

Voltage-sensing phosphoinositide phosphatase (VSP) contains voltage sensor and cytoplasmic phosphatase domains. A unique feature of this protein is that depolarization-induced motions of the voltage sensor activate PtdIns(3,4,5)P3and PtdIns(4,5)P2phosphatase activities. VSP exhibits remarkable structural similarities with PTEN, the phosphatase and tensin homolog deleted on chromosome 10. These similarities include the cytoplasmic phosphatase region, the phosphoinositide binding region, and the putative membrane interacting C2 domain.
Protein Kinase D Signaling: Multiple Biological Functions in Health and Disease
Authors: Rozengurt Enrique
Published: March 2011

Protein kinase D (PKD) is an evolutionarily conserved protein kinase family with structural, enzymological, and regulatory properties different from the PKC family members. Signaling through PKD is induced by a remarkable number of stimuli, including G-protein-coupled receptor agonists and polypeptide growth factors. PKD1, the most studied member of the family, is increasingly implicated in the regulation of a complex array of fundamental biological processes, including signal transduction, cell proliferation and differentiation, membrane trafficking, secretion, immune regulation, cardiac hypertrophy and contraction, angiogenesis, and cancer. PKD mediates such a diverse array of normal and abnormal biological functions via dynamic changes in its spatial and temporal localization, combined with its distinct substrate specificity. Studies on PKD thus far indicate a striking diversity of both its signal generation and distribution and its potential for complex regulatory interactions with multiple downstream pathways, often regulating the subcellular localization of its targets.
Role of TRP Channels in the Regulation of the Endosomal Pathway
Authors: Abe Ken , Puertollano Rosa
Published: March 2011

Some members of the transient receptor potential (TRP) channel superfamily have proved to be essential in maintaining adequate ion homeostasis, signaling, and membrane trafficking in the endosomal pathway. The unique properties of the TRP channels confer cells the ability to integrate cytosolic and intraluminal stimuli and allow maintained and regulated release of Ca2+from endosomes and lysosomes.