Members of the CAR group of Ig‐like type I transmembrane proteins mediate homotypic cell adhesion, share a common overall extracellular domain structure and are closely related at the amino acid sequence level. CAR proteins are often found at tight junctions and interact with intracellular scaffolding proteins, suggesting that they might modulate tight junction assembly or function. However, impairment of tight junction integrity has not been reported in mouse knockout models or zebrafish mutants of CAR members. In (...) contrast, in the same knockout models deficits in gap junction communication were detected in several organ systems, including the atrioventricular node of the heart, smooth muscle cells of the intestine and the ureter and in Sertoli cells of the testes. Possible interactions between BT‐IgSF and connexin41.8 on the disturbed pattern of pigment stripes found in zebrafish mutants and between ESAM and connexin43 during hematopoiesis in the mouse are also discussed. On the basis of the combined data and phenotypic similarities between CAR member mutants and connexin mutants I hypothesize that they primarily play a role in the organization of gap junction communication. Also see the video abstract here: https://youtu.be/i0yq2KhuDAE. (shrink)

While the idea of crisis is prevalent in the post‐war Anglo‐American literature an higher education, it can also be argued that our higher education systems have achieved a great deal during this period. We need to ask, therefore, whether the identified crises are real or not. And, if not, we should consider why academics prefer to see crisis in so muck of what they do.

Lifelong learning is presented as a means for enabling individuals, organisations and nations to meet the challenges of an increasingly competitive world. It suggests an extension of opportunity,involving all adults, whatever their interests or experience. There is also, however, a strong sense of expectation, even compulsion, with emphasis given to vocational forms of study and participation.

Widening participation — though it has only recently been labelled as such — has been a continuing concern for policy makers and higher education institutions in the United Kingdom since 1945 (and before). This article reviews the evidence for four key target groups — women, lower socio-economic groups, mature adults and ethnic minorities — to produce an overall assessment, a score card, of what has been achieved, and what remains to be done. It concludes that, while progress in the recruitment (...) of women, mature adults and ethnic minorities has been substantial — though with some qualifications — it has been much less so for lower socio-economic groups. (shrink)

This article examines the relation between education, voting and representation, and, in particular, the argument that more highly educated people should have more votes, as they should be better at judging important political decisions. In the past this issue attracted the attention of great thinkers such as Plato, Aristotle, Newman and Mill. In the UK there is also a practical precedent, rarely recalled today, where for centuries university graduates had their own representatives in Parliament. There are also some interesting contemporary (...) arguments on the topic put forward in favour of an epistocracy (as some call it) by social scientists, but not educators. It seems that most educators would not now dare to suggest that the more highly educated might be given more votes, largely on the grounds of equity. (shrink)

While the idea of crisis is prevalent in the post-war Anglo-American literature an higher education, it can also be argued that our higher education systems have achieved a great deal during this period. We need to ask, therefore, whether the identified crises are real or not. And, if not, we should consider why academics prefer to see crisis in so much of what they do.

Was there ever a golden age of academe: a time when academics were able to pursue their own interests, had relatively light and undemanding teaching responsibilities, and enjoyed widespread respect from both the general public and policy makers? This article explores that question, primarily in the context of the United Kingdom, but with some reference to other systems as well. It attempts to separate the mythical elements of the golden age from the reported memories and analyses of both those who (...) were there at the time and subsequent authors. (shrink)

Claudins serve essential roles in regulating paracellular permeability properties within occluding junctions. Recent studies have begun to elucidate developmental roles of claudins within immature tissues. This work has uncovered an involvement of several claudins in determining tight junction properties that have an effect on embryonic morphogenesis and physiology. During zebrafish brain morphogenesis, Claudin‐5a determines the paracellular permeability of tight junctions within a transient neuroepithelial‐ventricular barrier that maintains the hydrostatic fluid pressure required for brain ventricular lumen expansion. (...) However, the roles of Claudins in development may well extend beyond being mere junctional components. Several post‐translational modifications of Claudins have been characterized that indicate a direct regulation by developmental signals. This review focuses on the involvement of Claudin‐5a in cerebral barrier formation in the zebrafish embryo and includes some speculations about possible modes of regulation. (shrink)

There are many morphologically distinct membrane structures with different functions at the surface of epithelial cells. Among these, adherens junctions (AJ) and tight junctions (TJ) are responsible for the mechanical linkage of epithelial cells and epithelial barrier function, respectively. In the process of new cell–cell adhesion formation between two epithelial cells, such as after wounding, AJ form first and then TJ form on the apical side of AJ. This process is very complicated because AJ formation triggers drastic (...) changes in the organization of actin cytoskeleton, the activity of Rho family of small GTPases, and the lipid composition of the plasma membrane, all of which are required for subsequent TJ formation. In this review, the authors focus on the relationship between AJ and TJ as a representative example of specialization of plasma membrane regions and introduce recent findings on how AJ formation promotes the subsequent formation of TJ. (shrink)

The learning society has been advocated as an answer to current economic, political and social problems by a wide coalition of interests, including politicians, employers and educators. Here we critically analyse the concept as a myth; that is, as an idea which may or may not have validity, but which many people believe in. For the purpose of this analysis, the learning society is set alongside four other myths upon which it builds: those of productivity, change, lifelong education and the (...) learning organisation. It is argued that the United Kingdom cannot currently be considered to be a learning society, nor is it likely to become one in the foreseeable future. But the idea of the learning society retains an important role as a myth, in drawing together and channelling energies in directions sought by policy-makers. (shrink)

The learning society has been advocated as an answer to current economic, political and social problems by a wide coalition of interests, including politicians, employers and educators. Here we critically analyse the concept as a myth; that is, as an idea which may or may not have validity, but which many people believe in. For the purpose of this analysis, the learning society is set alongside four other myths upon which it builds: those of productivity, change, lifelong education and the (...) learning organisation. It is argued that the United Kingdom cannot currently be considered to be a learning society, nor is it likely to become one in the foreseeable future. But the idea of the learning society retains an important role as a myth, in drawing together and channelling energies in directions sought by policy-makers. (shrink)

In an age of pressing global issues such as climate change, the necessity for countries to work together to resolve problems affecting multiple nations has never been more important. Interdisciplinarity in higher education is a key to meeting these challenges. Universities need to produce graduates, and leaders, who understand issues from different perspectives, and who can communicate with others outside the confines of their own disciplines. -/- Drawing on contributions from 37 scholars from Australia, New Zealand, Hong Kong, Malaysia, the (...) Netherlands and the United Kingdom, this volume examines issues inherent in providing interdisciplinary education within the structures of universities and proposes ways in which these issues might be best managed. -/- The book has a dual focus on perspectives and practicalities. Themes covered include: the need for graduates who can work within and across multi-disciplinary and multi-professional teams; interdisciplinary leadership; the critical importance of interdisciplinary thinking to meet global challenges; collaboration in interdisciplinary approaches to teaching and learning; the role of institutional and other systems to support interdisciplinary endeavours; the centrality of disciplines; balancing disciplinarity and interdisciplinarity; and the place of interdisciplinarity in graduate outcomes and attributes. Definitional aspects of interdisciplinary higher education and current interdisciplinary practice across a range of contexts are also examined. -/- Contributors represent a wide range of discipline areas, including accounting, academic development, agriculture, food and wine science, biotechnology, employment relations, environmental science, the health sciences, higher education, land and environment, languages and cultures, occupational therapy, science communication, social work and social policy. (shrink)

Adherens (AJ) and tight junctions (TJ) maintain cell‐cell adhesions and cellular polarity in normal tissues. Afadin, a multi‐domain scaffold protein, is commonly found in both adherens and tight junctions, where it plays both structural and signal‐modulating roles. Afadin is a complex modulator of cellular processes implicated in cancer progression, including signal transduction, migration, invasion, and apoptosis. In keeping with the complexities associated with the roles of adherens and tight junctions in cancer, afadin exhibits both (...) tumor suppressive and pro‐metastatic functions. In this review, we will explore the dichotomous roles that afadin plays during cancer progression. (shrink)

Radical curriculum policy transformations are emerging as a key strategy of universities across different countries as they move to strengthen their competitive position in a global knowledge era. This paper puts forward a ?global case study? research agenda in the under-researched area of university curriculum policy. The particular curriculum policies to be investigated point to potentially new forms of liberal education, and they resonate in varying degrees with contemporary patterns in Europe as well as longer standing patterns in the United (...) States. This research agenda stands to make a unique contribution with its ?whole curriculum? approach to: the examination of the relationship between curriculum content, pedagogy and assessment; the tracking of curriculum policy borrowing across different jurisdictions extending between global and local levels; and the investigation of historical antecedents of contemporary curriculum policy patterns. In particular, the proposed agenda features a rare combination of spatial and temporal dimensions of university curriculum policy flows. This research agenda will provide a strong empirical evidence base for extending theory building about university curriculum policy development, as well as policy ?learning? for policy makers, practitioners and scholars ? globally. (shrink)

Zonulin is a physiological modulator of intercellular tight junctions, which upregulation is involved in several diseases like celiac disease (CeD). The polyQ gliadin fragment binds to the CXCR3 chemokine receptor that activates zonulin upregulation, leading to increased intestinal permeability in humans. Here, we report a general hypothesis based on the structural connection between the polyQ sequence of the immunogenic CeD protein, gliadin, and enteric coccidian parasites proteins. Firstly, a novel interaction pathway between the parasites and the host is (...) described based on the structural similarities between polyQ gliadin fragments and the parasite proteins. Secondly, a potential connection between coccidial infections as a novel environmental trigger of CeD is hypothesized. Therefore, this report represents a promising breakthrough for coccidian research and points out the potential role of coccidian parasites as a novel trigger of CeD that might define a preventive strategy for gluten‐related disorders in general. Also see the video abstract here: https://youtu.be/oMaQasStcFI. (shrink)

The blood‐brain barrier (BBB) is a complex structure formed by vascular endothelial cells, which serve to stabilize the homeostasic processes that are essential for neural functioning. The barrier relies on tight junctions between neighboring endothelial cells and a highly restricted passage of blood‐borne components through the endothelial lining. Selective transport mechanisms guarantee the essential import and export of metabolites through the BBB into and out of the neural microenvironment. The dual functions of barrier and carrier depend on distinct (...) proteins, some of which have been characterized in detail. (shrink)

It is often suggested that during development the brain barriers are immature. This argument stems from teleological interpretations and experimental observations of the high protein concentrations in fetal cerebrospinal fluid (CSF) and decreases in apparent permeability of passive markers during development. We argue that the developmental blood–CSF barrier restricts the passage of lipid‐insoluble molecules by the same mechanism as in the adult (tight junctions) rendering the paracellular pathway an unlikely route of entry. Instead, we suggest that both protein (...) and passive markers are transferred across the epithelium through a transcellular route. We propose that changes in volume of distribution can largely explain the decrease in apparent permeability for passive markers and that developmentally regulated cellular transfer explains changes in CSF protein concentrations. The blood–CSF tight junctions are functionally mature from very early in development, and it appears that transfer from blood into embryonic brain occurs predominately via CSF rather than the vasculature. BioEssays 30:237–248, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

The ectoplasmic specialization (ES) is a testis‐specific, actin‐based hybrid anchoring and tight junction. It is confined to the interface between Sertoli cells at the blood–testis barrier, known as the basal ES, as well as between Sertoli cells and developing spermatids designated the apical ES. The ES shares features of adherens junctions, tight junctions and focal contacts. By adopting the best features of each junction type, this hybrid nature of ES facilitates the extensive junction‐restructuring events in the (...) seminiferous epithelium during spermatogenesis. For instance, the α6β1‐integrin–laminin 333 complex, which is usually limited to the cell–matrix interface in other epithelia to facilitate cell movement, is a putative apical ES constituent. Furthermore, JAM‐C and CAR, two tight junction integral membrane proteins, are also components of apical ES involving in spermatid orientation. We discuss herein the mechanisms that maintain the cross‐talk between ES and blood–testis barrier to facilitate cell movement and orientation in the seminiferous epithelium. BioEssays 29: 36–48, 2007. © 2006 Wiley Periodicals, Inc. (shrink)

In the seminiferous tubule of the mammalian testis, one type A1 spermatogonium (diploid, 2n) divides and differentiates into 256 spermatozoa (haploid, n) during spermatogenesis. To complete spermatogenesis and produce ∼150 × 106 spermatozoa each day in a healthy man, germ cells must migrate progressively across the seminiferous epithelium yet remain attach to the nourishing Sertoli cells. This active cell migration process involves precisely controlled restructuring events at the tight (TJ) and anchoring junctions at the cell–cell interface. While the (...) hormonal events that regulate spermatogenesis by follicle‐stimulating hormone and testosterone from the pituitary gland and Leydig cells, respectively, are known, less is known about the mechanism(s) that regulates junction restructuring during germ cell movement in the seminiferous epithelium. The relative position of tight (TJs) and anchoring junctions in the testis is of interest. Sertoli cell TJs that constitute the blood–testis barrier (BTB) are present side by side with anchoring junctions and are adjacent to the basement membrane. This intimate physical association with the TJs, the anchoring junctions and the basement membrane (a modified form of extracellular matrix, ECM) suggests a role for the ECM in the junction dynamics of the testis. Indeed, evidence is accumulating that ECM proteins are crucial to Sertoli cell TJ dynamics. In this review, we discuss the pivotal role of tumor necrosis factor α (TNFα) on BTB dynamics via its effects on the homeostasis of ECM proteins. In addition, discussion will also be focused on the novel findings regarding the role of non‐basement‐membrane‐associated ECM proteins and components of focal adhesion (a cell–matrix anchoring junction type) in the regulation of junction dynamics in the testis. BioEssays 26:978–992, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

MUC1 and MUC4 are the two membrane mucins that have been best characterized. Although they have superficially similar structures and have both been shown to provide steric protection of epithelial surfaces, recent studies have also implicated them in cellular signaling. They act by substantially different mechanisms, MUC4 as a receptor ligand and MUC1 as a docking protein for signaling molecules. MUC4 is a novel intramembrane ligand for the receptor tyrosine kinase ErbB2/HER2/Neu, triggering a specific phosphorylation of the ErbB2 in the (...) absence of other ErbB ligands and potentiating phosphorylation and signaling through the ErbB2/ErbB3 heterodimeric receptor complex formed in the presence of neuregulin. In contrast, MUC1 has a highly conserved cytoplasmic tail, which binds β‐catenin, a key component of adherens junctions and a regulator of transcription, in a process that is tightly regulated by MUC1 phosphorylation. The specific localization of these membrane mucins to the apical surfaces of epithelial cells suggests that their signaling functions may be important as sensor mechanisms in response to invasion or damage of epithelia. BioEssays 25:66–71, 2003. © 2002 Wiley Periodicals, Inc. (shrink)

The field programmable gate array implementation of the nonlinear resistor-capacitor-inductor shunted Josephson junction model and its application to sEMG signal encryption through image encrypted technique are reported in this study. Thanks to the numerical simulations and FPGA implementation of the NRCISJJ model, different shapes of chaotic attractors are revealed by varying the parameters. The chaotic behaviour found in the NRCISJJ model is used to encrypt the sEMG signal through image encryption technique. The results obtained are interesting and open up many (...) perspectives. (shrink)

Gap junctions are ubiquitous plasma membrane specializations that allow cells to exchange small molecules and ions directly. The isolation, biochemical characterization and molecular cloning of the major protein of rat liver gap junctions lead to a clearer view of these membrane zones that allow cells to ‘talk’ to each other and co‐ordinate their activities in tissues and organs.

The integrity of epithelia depends largely on specialised adhesive structures, the adherens junctions. Several of the components required for building these structures are highly conserved between vertebrates and insects (e.g. E‐cadherin and α‐ and β‐catenin), while others have so far been found only in invertebrates (e.g. crumbs). Two recent papers(1,2) show that the Drosophila E‐cadherin is encoded by the gene shotgun. Phenotypic analyses of shotgun as well as armadillo (β‐catenin) and crumbs mutants provide new insights into the mechanisms by (...) which adherens junctions are built and, further, show that the requirement for E‐cadherin largely depends on the morphogenetic activity of an epithelium. (shrink)

In this essay we take the view that too much reality has been afforded to the notion of ‘particles’ and to ‘flow of supercurrent,’ in the superconducting state. Instead we take the original point of view of Josephson that “ It is clear that intuition is of no great help in understanding the supercurrent as a flow of Cooper pairs “ which is more akin to, and in line with, a “telegraphing of amplitudes” approach. With this conception in mind, we (...) examine the results of Jillie et al and Smith et al. of two Josephson junctions connected in series by a superconducting join. We argue that their results can best be understood in terms of the entanglement of current elements via the interfering of amplitudes. We sketch an approach to calculating the current spanning two entangled Josephson junctions, which reduces to the relation for a single junction when the current is set zero in either of the pair, or the entanglement ceases. We speculate that if this interfering of amplitudes was found to persist, after the separation of the junctions in space, there still remaining a connection in their common past, then this would furnish, at least the possibility, of a new means of signalling without wires. Experiments are suggested. (shrink)

Adherens junctions play pivotal roles in cell and tissue organization and patterning by mediating cell adhesion and cell signaling. These junctions consist of large multiprotein complexes that join the actin cytoskeleton to the plasma membrane to form adhesive contacts between cells or between cells and extracellular matrix. The best-known adherens junction is the zonula adherens (ZA) that forms a belt surrounding the apical pole of epithelial cells. Recent studies in Drosophila have further illuminated the structure of adherens (...) class='Hi'>junctions. Scaffolding proteins encoded by the stardust gene are novel components of the Crumbs complex, which plays a critical role in ZA assembly.1-3 The small GTPase Rap1 controls the symmetric re-assembly of the ZA after cell division.4 Finally, the asymmetric distribution of adherens junction material regulates spindle orientation during asymmetric cell division in the sensory organ lineage.5 BioEssays 24:690–695, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

A theory T is tight if different deductively closed extensions of T (in the same language) cannot be bi-interpretable. Many well-studied foundational theories are tight, including $\mathsf {PA}$ [39], $\mathsf {ZF}$, $\mathsf {Z}_2$, and $\mathsf {KM}$ [6]. In this article we extend Enayat’s investigations to subsystems of these latter two theories. We prove that restricting the Comprehension schema of $\mathsf {Z}_2$ and $\mathsf {KM}$ gives non-tight theories. Specifically, we show that $\mathsf {GB}$ and $\mathsf {ACA}_0$ each admit (...) different bi-interpretable extensions, and the same holds for their extensions by adding $\Sigma ^1_k$ -Comprehension, for $k \ge 1$. These results provide evidence that tightness characterizes $\mathsf {Z}_2$ and $\mathsf {KM}$ in a minimal way. (shrink)

This article summarizes Carroll Izard’s contributions to theory and research on emotion competence and an emotion-centered preventive intervention program. Cal’s contributions to emotion competence research began with some of the earliest studies of whether or not recognition and labeling of emotions relate to social and behavioral functioning. He also theorized about the adaptive use of discrete emotions, a construct Cal termed “emotion utilization.” He translated theory and research on emotions into seven principles for emotion-based prevention and intervention, and he applied (...) these principles to a preventive intervention, the Emotions Course. The Emotions Course has been shown to promote emotion competence and reduce problem behaviors. The article concludes with recommendations to deepen the research base on emotion competence. (shrink)

The intercellular junctions connecting the cytoplasms of fibre cells in the mammalian lens have until recently been regarded as a class of junction which is fundamentally different from that of the gap junctions in other organs. Recent observations, however, suggest that the lens junctions fit protein topology predictions common for all gap junctions. While the homologous peptide portions are predicted to form the channels, the divergent peptide portions of the gap junction polypeptides may adapt channel activity (...) to the special tissue requirements. (shrink)

Gap junction intercellular communication channels permit the exchange of small regulatory molecules and ions between neighbouring cells and coordinate cellular activity in diverse tissue and organ systems. These channels have short half‐lives and complex assembly and degradation pathways. Much of the recent work elucidating gap junction biogenesis has featured the use of connexins (Cx), the constituent proteins of gap junctions, tagged with reporter proteins such as Green Fluorescent Protein (GFP) and has illuminated the dynamics of channel assembly in live (...) cells by high‐resolution time‐lapse microscopy. With some studies, however, there are potential short‐comings associated with the GFP chimeric protein technologies. A recent report by Gaietta et al., has highlighted the use of recombinant proteins with tetracysteine tags attached to the carboxyl terminus of Cx43, which differentially labels ‘old’ and ‘new’ connexins thus opening up new avenues for studying temporal and spatial localisation of proteins and in situ trafficking events.1 BioEssays 24:876–880, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

Through accessible text and dynamic photos, readers will learn about the concepts of tight and loose using such topics as knots, rings, and clothing. A “Words to Know” section at the beginning of the book helps students learn new vocabulary they will encounter in the text, while suggestions for other titles and websites encourage students to learn more.

Most parts of the brain are conserved across reptiles and birds (sauropsids) and mammals. Two major qualitative differences occur in the upper part, or pallium, of the telencephalon, the most rostral part of the brain. Mammals have a six‐layered neocortex and also exhibit a different morphological organization in the lateral half, or sector, of their pallium than do sauropsids. These differences of lateral pallial construction may derive from small but crucial differences in migration patterns of neuronal precursors generated at or (...) above the corner of the lateral ventricle, the corticostriatal junction (CS). Sauropsids have a large structure, the dorsal ventricular ridge, that is proliferated from this region, and its anterior part (ADVR) receives ascending projections from the dorsal thalamus. Mammals have multiple structures in this same region—the lateral part of neocortex, amygdala, and claustrum‐endopiriform formation. We propose here that, as the degree of development of structures that form the deeper tier of the pallium varies across the stages of embryology and across phylogeny, mutations may have occurred during evolution at the origin of mammals that had profound consequences for the fate of neural populations generated in the region of the CS and its neighboring pallial germinal zone. BioEssays 24:530–541, 2002. © 2002 Wiley Periodicals, Inc. (shrink)

We propose that interaction rules derived from polyamine exchange in connected cells may explain the spatio‐temporal organization of gap junctions observed during tissue regeneration and tumorigenesis. We also hypothesize that polyamine exchange can be considered as signal that allows cells to sense the proliferation status of their neighbors. Polyamines (putrescine, spermidine, and spermine) are indeed small aliphatic polycations that serve as fuels to sustain elevated proliferation rates of the order observed in cancer cells. Based on recent reports, we consider (...) here that polyamines can be exchanged through gap junction channels between mammalian cells. Such intercellular exchange of polyamines has critical consequences on the local control of growth. In line with this hypothesis, the complex protein network that keeps polyamine levels finely tuned in mammalian cells can translate polyamine efflux or influx into integrated signals controlling transcription, translation, and cell communications. (shrink)

Talk therapy is, by definition, difficult, if not impossible, to represent materially. Whereas other scholars have sought to do so by referencing Sigmund Freud’s drawings or the setting of his consulting room, this article looks instead to the use of cloth in Joanne Greenberg’s 1964 semiautobiographical novel I Never Promised You a Rose Garden. The two main treatments given to protagonist Deborah Blau were therapy sessions with Dr. Clara Fried, based on Frieda Fromm-Reichmann, and the “cold pack,” in which the (...) patient was restrained and wrapped in sheets drenched with ice water. The two treatments, this article argues, can be considered in parallel, and through analysis of the material descriptions of the cold pack, one can learn more about the talking cure. Namely, this article analyzes the care in both cases as one of constraint, giving material form to the metaphorical “holding environment” of psychoanalyst D. W. Winnicott. Deborah uses the cold pack to endure her psychosis and return to reality. Similarly, Winnicott describes the ideal therapeutic space as one that, by its reliability, allows regression in service of finding a new self and distinguishing between fantasy and the outside world. The aim of this article is thus twofold: one, to further elucidate the role of cloth in treating mental distress, and two, to understand more fully the therapeutic relationship via the literal and figurative constraint of treatment. (shrink)