The complexity of our ‘object’ of study, leading to the question ‘what is really the city?’ requires the use of different levels of analyses. At the same time, a way must be found to develop an explanatory model that brings together the knowledge thus produced. The study of governance in the city is necessarily part of any research aimed at investigating empirically the processes regulating the social life. The key implication is to address its impact; a task made particularly complex (...) by the often difficult relationship between the implementation of governance and the interaction with a diversity of societal actors, for the ongoing dialectic between the formal and the informal in urban life. We often find that this dialectic produces ambiguity, unexpected results, gaps between planned objectives, and competition instead of cooperation among actors, pointing to the weakness of the rationalistic model of public action. Perhaps the most important lesson that we have learnt about government and governance is that the delusion that we feel when trying to understand urban policies results from our incapacity fully to grasp the complexity of human life. (shrink)

Diogenes, Ahead of Print. The complexity of our ‘object’ of study, leading to the question ‘what is really the city?’ requires the use of different levels of analyses. At the same time, a way must be found to develop an explanatory model that brings together the knowledge thus produced. The study of governance in the city is necessarily part of any research aimed at investigating empirically the processes regulating the social life. The key implication is to address its impact; a (...) task made particularly complex by the often difficult relationship between the implementation of governance and the interaction with a diversity of societal actors, for the ongoing dialectic between the formal and the informal in urban life. We often find that this dialectic produces ambiguity, unexpected results, gaps between planned objectives, and competition instead of cooperation among actors, pointing to the weakness of the rationalistic model of public action. Perhaps the most important lesson that we have learnt about government and governance is that the delusion that we feel when trying to understand urban policies results from our incapacity fully to grasp the complexity of human life. (shrink)

This article asks whether a myth can be collapsed into history by describing the material signs of memory as "evidence." In a story dear to the Venetian hearts, in 1177 the Republic of Venice defeated the imperial fleet and brought peace back to Italy. For centuries, this narrative was recounted and its truth upheld against growing political and scholarly criticism, first through the ritual display of evidence, then through its discussion in a large literary production. In the seventeenth century, it (...) is argued, the notion of evidence was abandoned in favor of the sheer affirmation of power. (shrink)

The key role played by online platforms in the neo-intermediation of the public debate requires a review of current tools for mapping the digital information ecosystem, highlighting the political nature of such an analysis: Starting from a synoptic overview of the main models of platform governance, we try to understand whether the ongoing European shift towards the Limited Government Regulation (LGR) model will be able to counterbalance the “systemic opinion power” of the giant platforms and restore the “health” of the (...) digital information ecosystem. A close analysis of the European Digital Services Act (DSA) has highlighted some limitations in achieving its goals, because of the features of the LGR on the one hand, and the disruptive features of the algorithmic neo-intermediation phenomenon on the other. Thus, we suggest a tripartite regulatory model, that can be defined as “neo-editorial accountability.” However, increasing users’ critical algorithmic awareness is an essential prerequisite for implementing the suggested template, and mitigating an outstanding effect of the LGR model: the normalization of the ideological assumptions underlying informational capitalism. (shrink)

In vitro experimental approaches are of central importance to contemporary molecular and cellular biology and toxicology. However, the scientific value or impact of in vitro results depends on their relevance in vivo. In vitro effect studies address inobservable in vivo phenomena through experiments on analogous in vitro phenomena. We present a theoretical basis developed to evaluate the in vivo relevance of in vitro effect studies. As a case study, the procedure for measuring specific gene transcription in isolated (...) cell nuclei (nuclear run-off method) is analyzed It is concluded that current evidence fails to justify in vivo interpretations of nuclear run-off experiments within the framework of theoretical models of transcription, implying that quantitative in vivo interpretations are unwarranted. Qualitative interpretations of nuclear run-off experiments may be justified by inferring the best explanation, especially when significant in vitro effects follow in vivo perturbations.Elements of a general theory are proposed. It is concluded that quantitative in vivo interpretations are warranted primarily in biochemical quantitation of biomolecules, while studies on biological function should be interpreted qualitatively in terms of causal explanations. Inferences to the best explanations are strengthened through additional evidence and the creation of experimental differences (effects). (shrink)

In vivo explore des questions fondamentales et des moments cruciaux de l’existence humaine – l’entrée en interaction avec une culture étrangère, la décision de se sortir d’une condition de vie routinière ou malheureuse, une action généreuse posée dans un contexte quotidien ordinaire – en fonction de leur potentiel de transformation de l’existence. En recourant à des illustrations tirées de la vie réelle et d’œuvres de fiction, Gabor Csepregi révèle le rôle primordial des sentiments personnels dans le façonnement de la (...) vie humaine et démontre le pouvoir formateur de la spontanéité en dehors du contexte traditionnel de l’éducation formelle. Ces moments, et notamment la façon dont ils perturbent l’ordre temporel ordinaire constituent des expériences vécues de notre vitalité. « Recourant à un langage clair et précis, In vivo captivera les philosophes et les intellectuels. Csepregi engage un dialogue entre diverses traditions, faisant appel aux meilleurs courants de plusieurs philosophies pour développer un point de vue unique ». - Gaëlle Fiasse, Université McGill. (shrink)

The recombinational repair of chromosomal double‐strand breaks (DSBs) is of critical importance to all organisms, who devote considerable genetic resources to ensuring such repair is accomplished. In Saccharomyces cerevisiae, DSB‐mediated recombination can be initiated synchronously by the conditional expression of two site‐specific endonucleases, HO or I‐Scel. DNA undergoing recombination can then be extracted at intervals and analyzed. Recombination initiated by meiotic‐specific DSBs can be followed in a similar fashion. This type of ‘in vivo biochemistry’ has been used to describe (...) several discrete steps in two different homologous recombination pathways: gene conversion and single‐strand annealing. The roles of specific proteins during recombination can be established by examining DNA in strains deleted for the corresponding gene. These same approaches are now becoming available for the study of recombination in both higher plants and animals. Physical monitoring can also be used to analyze nonhomologous recombination events, whose mechanisms appear to be conserved from yeast to mammals. (shrink)

In the context of a largely exploratory inquiry, I warn against oversimplifying the relationships among intuitions, emotions, principle-governed reasoning, and responsiveness to reasons. I point out that one cannot determine the normative status of some fact without determining whether a case can be made for this status. But I also note that, though reason is thus autonomous, every episode of reasoning depends causally on the way things nonnormatively are, and this makes it possible for any reasoner to challenge even her (...) most basic normative assumptions. (shrink)

The course of human life, punctuated by unexpected and transformative moments, is never uniform. What are the characteristics of such life-defining moments, what responses do they evoke, and how do they transform the lives of those who experience them? In Vivo explores foundational questions and pivotal moments of the human experience – engagement with a foreign culture, the decision to break free from unfortunate experiences, a generous action undertaken in the context of an otherwise regular day – in terms (...) of their life-altering potential. Through illustrative examples, both real and fictional, Csepregi reveals the primacy of personal feelings in shaping human life and demonstrates the formative power of spontaneity outside the traditional context of formal education. These moments, and particularly the way they disrupt ordinary temporal order, Csepregi argues, are the lived experiences of our vitality. In an age marked by increasing anxiety about the homogenizing tendencies of contemporary life, In Vivo is timely and revelatory. Informed by a range of philosophical thinking and examples from art, music, and literature, it illustrates opportunities for meaningful reflection that are available to everyone, and urges the reader to engage with them. (shrink)

Experimental modeling in biology involves the use of living organisms (not necessarily so-called "model organisms") in order to model or simulate biological processes. I argue here that experimental modeling is a bona fide form of scientific modeling that plays an epistemic role that is distinct from that of ordinary biological experiments. What distinguishes them from ordinary experiments is that they use what I call "in vivo representations" where one kind of causal process is used to stand in for a (...) physically different kind of process. I discuss the advantages of this approach in the context of evolutionary biology. (shrink)

Cranial electrical stimulation has been applied at various current levels in both adults and children with neurological conditions with seemingly promising but somewhat inconsistent results. Stimulation-induced spatial electric fields within a specific brain region are likely a significant contributing factor for the biological effects. Although several simulation models have been used to predict EF distributions in the brain, these models actually have not been validated by in vivo CES-induced EF measurements in the live human brain. This study directly measured (...) the CES-induced voltage changes with implanted stereotactic-electroencephalographic electrodes in twenty-one epilepsy participants and then compared these measured values with the simulated ones obtained from the personalized models. In addition, we further investigated the influence of stimulation frequency, intensity, electrode montage and age on EFs in parts of participants. We found both measured voltages and EFs obtained in vivo are highly correlated with the predicted ones in our cohort. In white matter and gray matter, the measured voltages linearly increased when the stimulation intensity increased from 5 to 500 μA but showed no significant changes with changing stimulation frequency from 0.5 to 200 Hz. Electrode montage, but not age, significantly affects the distribution of the EFs. Our in vivo measurements demonstrate that the individualized simulation model can reliably predict the CES-induced EFs in both adults and children. It also confirms that the CES-induced EFs highly depend on the electrode montages and individual anatomical features. (shrink)

manganese (Mn2+) enhanced MRI (MEMRI) to study neuronal connectivity in vivo opens the possibility to these studies. However, several drawbacks exist that challenge its applicability. High Mn2+ concentrations produce cytotoxic effects that can perturb the circuits under study. In the other hand, the MR signal is..

This is a review of the book by Leo S. Klein “The Tortures of Science: A Scientist and Power, a Scientist and Money, a Scientist and Morals” (Moscow: Novoe literaturnoe obozreniye, 2017. 576 pp). The review presents the book’s structure and the key topics; marks some controversial points and conclusions made by the author. The review is dedicated to the recent 90th anniversary of Professor Leo S. Klein.

Hippocampal neurogenesis has been implicated in the pathogenesis of and recovery from depression. However, most of the underlying studies were endpoint investigations in experimental animals yielding conflicting results, and it has been under debate to which extent these results could be transferred to human patients. Now, researchers have developed a powerful new tool to address these questions by a non‐invasive method in humans and animals in vivo, using magnetic resonance spectroscopy to detect a biomarker for proliferating progenitor cells that (...) give rise to new neurons.1 This makes it possible to study the role of neural progenitor cells in a wide variety of human brain disorders. BioEssays 30:806–810, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

Scientific practices have been changed by the increasing use of computer simulations. A central question for philosophers is how to characterize computer simulations. In this paper, we address this question by analyzing simulations in biochemistry. We propose that simulations have been used in biochemistry long before computers arrived. Simulation can be described as a surrogate relationship between models. Moreover, a simulative aspect is implicit in the classical dichotomy between in vivo–in vitro conditions. Based on a discussion about how to (...) characterize a simulative aspect in this dichotomy, we will argue that an adequate understanding of computer simulations in biochemistry requires a previous understanding of simulations in experimental contexts. (shrink)

Csepregi, Gabor In Vivo: A Phenomenology of Life-Defining MomentsMontreal: McGill-Queen’s University Press, 216 p.ISBN 978-0773556638.

Nanomaterials have the promise of revolutionizing current treatment and diagnosis of diseases, which has led to 33 nanotherapeutics drugs currently on the market and many more in various stages of clinical trials. With an increasing number of products available and in development, along with the unique, emergent properties of the nanoparticle therapeutics themselves, regulatory agencies are now faced with decisions regarding the regulation of such novel technologies. Regulatory guidance, particularly in pre-clinical stages, has the potential to facilitate quick and safe (...) development of these novel materials, but new regulation beyond what is currently in place must be justified in a clear and distinctive toxic response. Herein, we examine literature that compares and correlates in vivo and in vitro nanotoxicity studies to gain a deeper understanding of the modes of nanoparticle toxicity. Additionally, this comparison aims to identify clear and unique toxicity responses caused by nanoparticles, which informs our perspective on pre-clinical nanotherapeutic oversight. (shrink)

Much of the focus of the published 2011 symposium that inspired this work focused on the question, “When have you reduced risk enough to move from bench/animal studies to ‘first in-human’ studies?” Building applied research ethics related to nanotherapeutics requires bench and clinical scientists to have a clear vision about how to test nanotherapeutic safety, and it is clear that there is still much to be considered at the steps before “in-human” assessment. Herein, the perspective of the bench scientist is (...) brought to bear on using in vivo and in vitro models to assess the safety of nanotherapeutics. Much of this work falls under the purview of the field of nanotoxicology that aims to understand the toxicological impact of engineered nanoscale materials. Engineered nanomaterials include a wide variety of materials that are manipulated and controlled on the nanoscale level where, typically, the nanoparticle or nanomaterial has some dimension that is less than 100 nm. (shrink)

The development of new approaches is critical to gain further insights into biological processes that cannot be obtained by existing methods or technologies. The detection of protein–protein interaction is often challenging, especially for weak and transient interactions or for membrane proteins. Over the last decade, several proximity‐tagging methodologies have been developed to explore protein interactions in living cells. Among those, the most efficient are based on protein partner modification, such as biotinylation or pupylation. Such technologies are based on engineered variants (...) of enzymes like peroxidases or ligases that release reactive molecules, in the presence of specific substrates, that bind surrounding proteins. Fusing a protein of interest (POI) to these enzymes allows the definition of an unbiased “proxisome,” that is, all of the proteins in interaction or in close vicinity of the POI. Here, the different proximity‐labeling tools available are described and comprehensive comparison to discuss advantages and limitations is provided. (shrink)

[Przekład] Ja immunologiczne jest naszym zreifikowanym opisem procesów, dzięki którym układ odpornościowy utrzymuje wyodrębnioną tożsamość organizmu i siebie samego. Jest to proces interpretacyjny, i żeby badać go w sposób naukowo konstruktywny, powinniśmy połączyć długoletnią hermeneutyczną tradycję pytania o naturę interpretacji ze współczesnym rozumieniem układu odpornościowego, pojawiającymi się technologiami badawczymi oraz zaawansowanymi narzędziami obliczeniowymi analizującymi dane sensoryczne.

Background: Magnetic resonance spectroscopic imaging is a neuroimaging technique that may be useful for non-invasive mapping of brain temperature over a large brain volume. To date, intra-subject reproducibility of MRSI-based brain temperature has not been investigated. The objective of this repeated measures MRSI-t study was to establish intra-subject reproducibility and repeatability of brain temperature, as well as typical brain temperature range.Methods: Healthy participants aged 23–46 years were scanned at two time points ~12-weeks apart. Volumetric MRSI data were processed by reconstructing (...) metabolite and water images using parametric spectral analysis. Brain temperature was derived using the frequency difference between water and creatine for 47 regions of interest delineated by the modified Automated Anatomical Labeling atlas. Reproducibility was measured using the coefficient of variation for repeated measures, and repeatability was determined using the standard error of measurement. For each region, the upper and lower bounds of Minimal Detectable Change were established to characterize the typical range of TCRE values.Results: The mean global brain temperature over all subjects was 37.2°C with spatial variations across ROIs. There was a significant main effect for time [F = 37.0, p < 0.0001] and for brain region [F = 2.66, p < 0.0001]. The time*brain region interaction was not significant [F = 0.80, p = 0.83]. Participants' TCRE was stable for each ROI across both time points, with ROIs' COVrep ranging from 0.81 to 3.08% ; majority of ROIs had a COVrep <2.0%.Conclusions: Brain temperature measurements were highly consistent between both time points, indicating high reproducibility and repeatability of MRSI-t. MRSI-t may be a promising diagnostic, prognostic, and therapeutic tool for non-invasively monitoring brain temperature changes in health and disease. However, further studies of healthy participants with larger sample size and numerous repeated acquisitions are imperative for establishing a reference range of typical brain TCRE, as well as the threshold above which TCRE is likely pathological. (shrink)

Edward O. Wilson's forays into human sociobiology have been the target of persistent, vehement attack by his Harvard colleague in evolutionary biology, Richard C. Lewontin. Through examination of existing documents in the case, together with in-depth personal interviews of Wilson, Lewontin, and other biologists, the reasons for Wilson's stance and Lewontin's criticisms are uncovered. It is argued that the dispute is not primarily personally or politically motivated, but involves a conflict between long-term scientific-cum-moral agendas, with the reductionist program as a (...) key issue. It is concluded that it is in the interest of both disputants to keep the controversy alive. (shrink)

Nucleosome positioning refers to sequence‐specific locations for histones interacting with the nucleic acid. Examples of occurrence of this phenomenon, its possible mechanisms and its significance are presented.

The relevance of nonlinear dynamics to calcium metabolism led us to reevaluate the role of Ca-regulating hormones in Ca homeostasis. We suggest that, firstly, the main Ca metabolic functions in rat-bone and gut - are organized as dynamic entities able to generate various temporal expressions, including self-oscillating patterns and, secondly, Ca homeostasis results from interaction between both metabolic and hormonal oscillators. Following this schema, a major role for the hormonal system, with its circadian pattern, could be to act directly on (...) metabolic functions or indirectly through feeding behaviour, in order to optimize, coordinate and synchronize the Ca fluxes at ECF level. (shrink)

The temporal behaviour of the nonlinear compartmental model we have developed for rat calcium metabolism is discussed with respect to the theoretical properties of the self-oscillating autocatalytic subunit around which the model is constructed. Depending on the approximations made, this subunit is described by a minimal two-variable model, SU2, or by a three-variable one, SU3. The diversity of the theoretical dynamic behaviours possible with SU2 is greatly increased with SU3. But the identification of SU3 parameter values in three different experimental (...) situations reveals that biological constraints efficiently preserve a simple circadian rhythm for bone metabolism. This analysis indicates the significant contribution of the available bone crystal pool to the dynamic organization of this tissue, and hence to extracellular calcium homeostasis. (shrink)

Research on innovation often highlights analogies from sources outside the current problem domain as a major source of novel concepts; however, the mechanisms underlying this relationship are not well understood. We analyzed the temporal interplay between far analogy use and creative concept generation in a professional design team's brainstorming conversations, investigating the hypothesis that far analogies lead directly to very novel concepts via large steps in conceptual spaces . Surprisingly, we found that concepts were more similar to their preceding concepts (...) after far analogy use compared to baseline situations . Yet far analogies increased the team's concept generation rate compared to baseline conditions. Overall, these results challenge the view that far analogies primarily lead to novel concepts via jumps in conceptual spaces and suggest alternative pathways from far analogies to novel concepts. (shrink)

Rho/Rac proteins constitute a subgroup of the Ras superfamily of GTP hydrolases. Although originally implicated in the control of cytoskeletal events, it is currently known that these GTPases coordinate diverse cellular functions, including cell polarity, vesicular trafficking, the cell cycle and transcriptomal dynamics. In this review, we will provide an overview on the recent advances in this field regarding the mechanism of regulation and signaling, and the roles in vivo of this important GTPase family. BioEssays 29:356–370, 2007. © 2007 (...) Wiley Periodicals, Inc. (shrink)

The remodeling of biological membranes is crucial for a vast number of cellular activities and is an inherently multiscale process in both time and space. Seminal work has provided important insights into nanometer‐scale membrane deformations, and highlighted the remarkable variation and complexity in the underlying molecular machineries and mechanisms. However, how membranes are remodeled at the micron‐scale, particularly in vivo, remains poorly understood. Here, we discuss how using regulated exocytosis of large (1.5–2.0 μm) membrane‐bound secretory granules in the salivary (...) gland of live mice as a model system, has provided evidence for the importance of the actomyosin cytoskeleton in micron‐scale membrane remodeling in physiological conditions. We highlight some of these advances, and present mechanistic hypotheses for how the various biochemical and biophysical properties of distinct actomyosin networks may drive this process. (shrink)

Although the segregation of mesenchyme into distinct aggregates is the first step in the development of a range of tissues that includes bones, somites, feathers and nephrons, we still know very little about the mechanisms by which this happens. There are two obvious types of explanation: first, that there are global pre‐patterns within the mesenchyme whose molecular expression leads to tissue fragmentation and, second, that the condensations arise spontaneously through the local morphogenetic abilities of the cells. The only known mechanism (...) for the latter possibility is cell traction and this paper suggests that current studies are compatible with traction playing a primary role in the formation of nephrogenic condensations in the developing kidney and the separation of somites, but not for the generation of feather rudiments where there is evidence of a prepattern of adhesivity. (shrink)

The “Human Genome Project” was completed in 2003, shifting the focus to proteome and transcriptome research. One approach to proteomics involves the comprehensive visualization of the localization of proteins in all tissues and organs. We discuss in situ phospho‐protein atlases, which are systematized representations of the localization of proteins. Protein atlases provide important information about the identity and presence of proteins in specific organs, tissues and cells under physiological and pathological conditions. Antibody‐based immunohistochemical analysis is a powerful method for generating (...) a protein atlas. However, it is difficult to localize phosphorylated proteins under in vivo physiological conditions, even with immunohistochemistry, because these proteins tend to be dephosphorylated or phosphorylated due to the experimental manipulations. We also discuss an improved immunohistochemical method for precisely detecting phosphorylated protein, using the detection of phosphorylated ERK1/2 as an example. We consider that it is possible and useful to generate a phospho‐protein atlas. (shrink)

The assembly of nucleosomes and higher‐order chromatin structures has been extensively studied in vitro. Provided that non‐specific charge interactions are controlled, all the information for correct assembly is found to be inherent in the macromolecular components. Cellular extracts which can assemble chromatin in vitro with nucleosomes correctly spaced on the DNA have been studied in detail and also used to investigate the role of chromatin structure in transcription. However, the mechanisms of chromatin assembly in vivo are still controversial.

Skeletal muscle formation is studied in vitro with myogenic cell lines and primary muscle cell cultures, and in vivo with embryos of several species. We review several of the notable advances obtained from studies of cultured cells, including the recognition of myoblast diversity, isolation of the MyoD family of muscle regulatory factors, and identification of promoter elements required for muscle‐specific gene expression. These studies have led to the ideas that myoblast diversity underlies the formation of the multiple types of (...) fast and slow muscle fibers, and that myogenesis is controlled by a combination of ubiquitous and muscle‐specific transcriptional regulators that may be different for each gene. We further review some unexpected results that have been obtained when ideas from work in culture have been tested in developing animals. The studies in vivo point to additional molecular and cellular mechanisms that regulate muscle formation in the animal. (shrink)

The topology of DNA duplexes changes during replication and also after deproteinization in vitro. Here we describe these changes and then discuss for the first time how the distribution of superhelical stress affects the DNA topology of replication intermediates, taking into account the progression of replication forks. The high processivity of Topo IV to relax the left‐handed (+) supercoiling that transiently accumulates ahead of the forks is not essential, since DNA gyrase and swiveling of the forks cooperate with Topo IV (...) to accomplish this task in vivo. We conclude that despite Topo IV has a lower processivity to unlink the right‐handed (+) crossings of pre‐catenanes and fully replicated catenanes, this is indeed its main role in vivo. This would explain why in the absence of Topo IV replication goes‐on, but fully replicated sister duplexes remain heavily catenated. (shrink)

Identification of the molecular mechanisms underlying axonal branching in vivo has begun in several neuronal systems, notably the projections formed by dorsal root ganglion (DRG) neurons or retinal ganglion cells (RGC). cGMP signalling is essential for sensory axon bifurcation at the spinal cord, whereas brain‐derived neurotrophic factor (BDNF) and ephrinA signalling establish position‐dependent branching of RGC axons. In the latter system, the degradation of specific signalling components, via the ubiquitin‐proteasome system, may provide an additional mechanism involved in axon branching (...) of RGC. The process of arborisation is essential for neurons to innervate multiple targets and to build topographic maps. The various forms of branching found in different types of neurons are regulated by distinct signalling pathways activated by multiple extracellular cues in addition to axonal guidance factors. These signalling cascades, together with transcriptional programs, most likely interact and trigger the polymerisation or depolymerisation of the actin and tubulin cytoskeleton to regulate branching. (shrink)

This article reviews recent findings that bear on the mechanism(s) of tumor‐specific Lyt‐1+2− T cell‐mediated tumor eradication in vivo A tumor‐immune Lyt‐1+2− T cell subset has been identified which is distinct from T cells mediating in vitro cytotoxicity (Lyt‐1+2+/1−2+). The Lyt‐1+2− cells have a crucial role in rejecting tumor cells when adoptively transferred into T cell‐deprived B cell mice. This indicates that Lyt‐1+2− T cells do not necessarily require recruitment of the host's cytotoxic T cell precursors for implementation of (...) in vivo immunity. Instead, this T cell subset exerts its anti‐tumor effect in collaboration with macrophages as shown with an in vivo tumor cell culture system utilizing a diffusion chamber. A pathway of Lyt‐1+2− T cell‐macrophage interaction leading to tumor cell killing is discussed in terms of its probable relevance to the eradication of tumor cell masses consisting of tumor cells expressing quantitatively and/or qualitatively different tumor antigens. (shrink)

An interplay between DNA‐dependent biological processes appears to be crucial for cell viability. At the molecular level, this interplay relies heavily on the communication between DNA‐bound proteins, which can be facilitated and controlled by the dynamic structure of double‐stranded DNA. Hence, DNA structural alterations are recognized as potential tools to transfer biological information over some distance within a genome. Until recently, however, direct evidence for DNA structural information as a mediator between cellular processes was lacking. This changed when the concept (...) of transient waves of DNA supercoiling, induced by proteins tracking along the right‐handed DNA double helix, came into the limelight. Indeed, a number of observations now suggest that helix tracking‐induced DNA structural information might be exploited to participate in the regulation of a variety of DNA transactions in vivo. (shrink)

Special Care: Medical Decisions at the Beginning of Life, by Fred FronhockPlaying God in the Nursery, by Jeff LyonsWithholding Treatment From Defective Newborn Children, Joseph E. Magnet and Eike‐Henner W. KlugeCenter for Ethics, Medicine and Public Issues Baylor College of MedicineLAW AND MORALS by Simon Lee. OxfordThe Foetus as Organ donor: Scientific, Social and Ethical Perspectives. By Peter McCullaghTransplantation Unit The Walter & Eliza Hall Institute of Medical Research.