Understanding aging and how it affects an organism's lifespan is a fundamental problem in biology. A hallmark of aging is stem cell senescence, the decline of functionality, and number of somatic stem cells, resulting in an impaired regenerative capacity and reduced tissue function. In addition, aging is characterized by profound remodeling of the immune system and a quantitative decline of adequate immune responses, a phenomenon referred to as immune‐senescence. Yet, what is causing stem cell and immune‐senescence? This review discusses experimental (...) studies of potentially immortal Hydra which have made contributions to answering this question. Hydra transcription factor FoxO has been shown to modulate both stem cell proliferation and innate immunity, lending strong support to a role of FoxO as critical rate‐of‐aging regulator from Hydra to human. Constructing a model of how FoxO responds to diverse environmental factors provides a framework for how stem cell factors might contribute to aging. (shrink)

Current work in experimental biology revolves around a handful of animal species. Studying only a few organisms limits science to the answers that those organisms can provide. Nature has given us an overwhelming diversity of animals to study, and recent technological advances have greatly accelerated the ability to generate genetic and genomic tools to develop model organisms for research on host–microbe interactions. With the help of such models the authors therefore hope to construct a more complete picture of the mechanisms (...) that underlie crucial interactions in a given metaorganism (entity consisting of a eukaryotic host with all its associated microbial partners). As reviewed here, new knowledge of the diversity of host–microbe interactions found across the animal kingdom will provide new insights into how animals develop, evolve, and succumb to the disease. (shrink)

Cells in the basal metazoan phylum Cnidaria are characterized by remarkable plasticity in their differentiation capacity. The mechanism controlling asymmetric cell divisions is not understood in cnidarians or in any other animal group. PIWI proteins recently have been shown to be involved in maintaining the self‐renewal capacity of stem cells in organisms as diverse as ciliates, flies, worms and mammals. Seipel et al.1 find that, in the cnidarian Podocoryne carnea, the Piwi homolog Cniwi is transcriptionally upregulated when the polyp generates (...) buds, which will develop into medusae. Since transdifferentiation of striated muscle cells to smooth muscle cells also activated Cniwi expression, Cniwi appears to play a crucial role in differentiation events. The discovery should facilitate elucidation of the poorly understood factors that control asymmetric cell divisions at the beginning of animal evolution. BioEssays 26:929–931, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Hydra are remarkable because they are immortal. Much of immortality can be ascribed to the asexual mode of reproduction by budding, which requires a tissue consisting of stem cells with continuous self‐renewal capacity. Emerging novel technologies and the availability of genomic resources enable for the first time to analyse these cells in vivo. Stem cell differentiation in Hydra is governed through the coordinated actions of conserved signaling pathways. Studies of stem cells in Hydra, therefore, promise critical insights of general relevance (...) into stem cell biology including cellular senescence, lineage programming and reprogramming, the role of extrinsic signals in fate determination and tissue homeostasis, and the evolutionary origin of these cells. With these new facts as a backdrop, this review traces the history of studying stem cells in Hydra and offers a view of what the future may hold. (shrink)

While largely studied because of their harmful effects on human health, there is growing appreciation that bacteria are important partners for invertebrates and vertebrates, including man. Epithelia in metazoans do not only select their microbiota; a coevolved consortium of microbes enables both invertebrates and vertebrates to expand the range of diet supply, to shape the complex immune system and to control pathogenic bacteria. Microbes in zebrafish and mice regulate gut epithelial homeostasis. In a squid, microbes control the development of the (...) symbiotic light organ. These discoveries point to a key role for bacteria in any metazoan existence, and imply that beneficial bacteria‐host interactions should be considered an integral part of development and evolution. (shrink)

Cover Photograph: Transgenic Hydra provide insights of general relevance into stem cell biology. The image shows a mass culture of transgenic Hydra expressing EGFP in all of their ectodermal epithelial cells. See article by Thomas C. G. Bosch pp. 478–486.

Here we evaluate our current understanding of the function of the nervous system in Hydra, a non‐bilaterian animal which is among the first metazoans that contain neurons. We highlight growing evidence that the nervous system, with its rich repertoire of neuropeptides, is involved in controlling resident beneficial microbes. We also review observations that indicate that microbes affect the animal's behavior by directly interfering with neuronal receptors. These findings provide new insight into the original role of the nervous system, and suggest (...) that it emerged to orchestrate multiple functions including host‐microbiome interactions. The excitement of future research in the Hydra model now relies on uncovering the common rules and principles that govern the interaction between neurons and microbes and the extent to which such laws might apply to other and more complex organisms. (shrink)

Peptides serve as important signalling molecules in development and differentiation in the simple metazoan Hydra. A systematic approach (The Hydra Peptide Project) has revealed that Hydra contains several hundreds of peptide signalling molecules, some of which are neuropeptides and others emanate from epithelial cells. These peptides control biological processes as diverse as muscle contraction, neuron differentiation, and the positional value gradient. Signal peptides cause changes in cell behaviour by controlling target genes such as matrix metalloproteases. The abundance of peptides in (...) Hydra raises the question of whether, in early metazoan evolution, cell–cell communication was based mainly on these small molecules rather than on the growth‐factor‐like cytokines that control differentiation and development in higher animals. BioEssays 23:420–427, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Ecological developmental biology (eco‐devo) explores the mechanistic relationships between the processes of individual development and environmental factors. Recent studies imply that some of these relationships have deep evolutionary origins, and may even pre‐date the divergences of the simplest extant animals, including cnidarians and sponges. Development of these early diverging metazoans is often sensitive to environmental factors, and these interactions occur in the context of conserved signaling pathways and mechanisms of tissue homeostasis whose detailed molecular logic remain elusive. Efficient methods for (...) transgenesis in cnidarians together with the ease of experimental manipulation in cnidarians and sponges make them ideal models for understanding causal relationships between environmental factors and developmental mechanisms. Here, we identify major questions at the interface between animal evolution and development and outline a road map for research aimed at identifying the mechanisms that link environmental factors to developmental mechanisms in early diverging metazoans.Also watch the Video Abstract. (shrink)

Graphical AbstractCIFAR's Humans & the Microbiome program is a multidisciplinary group of biological, clinical, and social scientists who explore the links between microbiome biology and sociocultural, historical, evolutionary, and environmental aspects of human existence that may impact the microbiome or be impacted by it. In this focus issue, members of the program focus on topics ranging from decoding the link between nutrition, the microbiome and human developmental, metabolic, and immune health and aging, to understanding past changes in the environment and (...) microbiome. The image depicts a population of bacteria (green) in association with the epithelia tissues (magenta and blue), perhaps the most common type of symbiosis in humans and other animals. Image contribution: Tara Essock-Burns. DOI: 10.1002/bies.201900130. (shrink)

The conference explored an extraordinary diversity of aging strategies in organisms ranging from short‐lived species to “immortal” animals and plants. Research on the biological processes of aging is at the brink of a revolution with respect to our understanding of its underlying mechanisms as well as our ability to prevent and cure a wide variety of age‐related pathologies.

A reality-design gap in the conceptualization and practice of digital agriculture has been systematically reported in the literature. This condition is favored by the lack of understanding and inclusion of local worldviews around digital technologies. Informed by Amartya Sen’s capabilities approach, this study looks to bring stories of local appropriation to the spotlight. Based on a qualitative approach that included data collected through interviews with 73 households, the authors explored the way in which two selected communities of Colombian coffee growers (...) are engaged in the use of digital technologies in material and symbolic ways. Three emergent themes—a relational way of farming, (dis)connected machines, and nurtured families and communities – articulate multiple interactions between farmers, farms, institutional programs, and technologies, that originate local forms of digitalization (and non-digitalization). This study points out the relevant role of situated ideas of development in positioning technologies in or out of the farm, and broader digitalization agendas in or out of farmers’ life projects. At the same time, it presents a critique of notions of universality that drive unquestioned quests for technification. In contrast, building on a relational perspective, this study calls for embracing a perspective of multiplicity within notions of development and innovation. (shrink)

We report on the small-scale (0.5 13 h - 1M, a large-scale bias of ~2.0 and a satellite fraction of 12 ± 2 per cent. Thus, these galaxies occupy haloes with average masses in between those of the higher redshift BOSS CMASS sample and the original SDSS I/II luminous red galaxy sample © 2012 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society © doi:10.1093/mnras/sts314.

Humans’ indigenous microbes strongly influence organ functions in an age‐ and diet‐dependent manner, adding an important dimension to aging biology that remains poorly understood. Although age‐related differences in the gut microbiota composition correlate with age‐related loss of organ function and diseases, including inflammation and frailty, variation exists among the elderly, especially centenarians and people living in areas of extreme longevity. Studies using short‐lived as well as nonsenescent model organisms provide surprising functional insights into factors affecting aging and implicate attenuating effects (...) of microbes as well as a crucial role for certain transcription factors like forkhead box O. The unexpected beneficial effects of microbes on aged animals imply an even more complex interplay between the gut microbiome and the host. The microbiome constitutes the major interface between humans and the environment, is influenced by biosocial stressors and behaviors, and mediates effects on health and aging processes, while being moderated by sex and developmental stages. (shrink)

The microbiome of human hair follicles (HFs) has emerged as an important player in different HF and skin pathologies, yet awaits in‐depth exploration. This raises questions regarding the tightly linked interactions between host environment, nutrient dependency of host‐associated microbes, microbial metabolism, microbe‐microbe interactions and host immunity. The use of simple model systems facilitates addressing generally important questions and testing overarching, therapeutically relevant principles that likely transcend obvious interspecies differences. Here, we evaluate the potential of the freshwater polyp Hydra, to dissect (...) fundamental principles of microbiome regulation by the host, that is the human HF. In particular, we focus on therapeutically targetable host‐microbiome interactions, such as nutrient dependency, microbial interactions and host defence. Offering a new lens into the study of HF – microbiota interactions, we argue that general principles of how Hydra manages its microbiota can inform the development of novel, microbiome‐targeting therapeutic interventions in human skin disease. (shrink)

Meet the Metaorganism is a web‐based learning app that combines three fundamental biological concepts (coevolution, community dynamics, and immune system) with latest scientific findings using the metaorganism as a central case study. In a transdisciplinary team of scientists, information designers, programmers, science communicators, and educators, we conceptualized and developed the app according to the latest didactic and scientific findings and aimed at setting new standards in visual design, digital knowledge transfer, and online education. A content management system allows continuous integration (...) of new findings, which enables us to expand the app with the dynamics of the research field. Students can thus gain a close insight and connection to current research, and at the same time learn that knowledge is not static but grows dynamically. Especially in the realm of the easily accessible metaorganism research, visualization plays an essential role to keep complex processes understandable and memorable. Meet the Metaorganism is freely available online and can be accessed here: www.metaorganism.app. (shrink)

The evidence compiled in the target article demonstrates that the assumptions of cultural group selection theory are often met, and it is therefore a useful framework for generating plausible hypotheses. However, more can be said about how we can test the predictions of CGS hypotheses against competing explanations using historical, archaeological, and anthropological data.

This book is the second of two volumes devoted to the work of Theo Kuipers, a leading Dutch philosopher of science. Philosophers and scientists from all over the world, thirty seven in all, comment on Kuipers’ philosophy, and each of their commentaries is followed by a reply from Kuipers. The present volume is devoted to Kuipers’ neo-classical philosophy of science, as laid down in his Structures in Science . Kuipers defends a dialectical interaction between science and philosophy in that he (...) views philosophy of science as a meta-science which formulates cognitive structures that provide heuristic patterns for actual scientific research, including design research. In addition, Kuipers pays considerable attention to the computational approaches to philosophy of science as well as to the ethics of doing research. Thomas Nickles, David Atkinson, Jean-Paul van Bendegem, Maarten Franssen, Anne Ruth Mackor, Arno Wouters, Erik Weber & Helena de Preester, Eric Scerri, Adam Grobler & Andrzej Wisniewski, Alexander van den Bosch, Gerard Vreeswijk, Jaap Kamps, Paul Thagard, Emma Ruttkamp, Robert Causey, Henk Zandvoort comment on these ideas of Kuipers, and many present their own account. The present book also contains a synopsis of Structures in Science. It can be read independently of the first volume of Essays in Debate with Theo Kuipers, which is devoted to Kuipers’ From Instrumentalism to Constructive Realism. (shrink)

The biannual international workshop entitled “The diversification of early emerging metazoans: A window into animal evolution?” took place at the Evangelische Akademie Tutzing, Germany, 11–14. September 2017. It was organized by Thomas Bosch (Kiel), Thomas Holstein (Heidelberg), and Ulrich Technau (Vienna), and it was sponsored by the Deutsche Forschungsgemeinschaft (DFG). The meeting gathered over 140 researchers to discuss the contribution of non‐bilaterian metazoan models (Porifera, Ctenophora, Placozoa, and Cnidaria) to our understanding of: a. The evolution of metazoan (...) developmental processes; b. Fundamental molecular mechanisms underlying metazoan features; and c. The complex interactions that animals establish with their environment. (shrink)

Despite its complex experiential structure, the phenomenon of grief following bereavement has not been a major topic of phenomenological research. The paper investigates its basic structures, elaborating as its core characteristic a conflict between a presentifying and a ‘de-presentifying’ intention: In grief, the subject experiences a fundamental ambiguity between presence and absence of the deceased, between the present and the past, indeed between two worlds he lives in. This phenomenological structure will be analyzed under several aspects: regarding bodily experience, as (...) disruption of a shared intercorporeality; as a loss of the shared world and shared habitualities, leaving the bereaved person with ubiquitous indications of absence and with a contraction of their own self; regarding temporality, as a separation of two strands of time, namely a still ongoing past and an alienated present which become more and more desynchronized; finally, as an “as-if presence” of the deceased which the bereaved continue to feel and sometimes to perceive, leading to a cognitive-affective conflict between two experienced realities. The transforming process of grief is then analyzed as a gradual adjustment to the loss, finally enabling a re-integration of the conflicting realities. This is achieved through an incorporation and identification with the deceased on the one hand, and through various forms of representation on the other hand, in particular by recollection and symbolization. (shrink)

The hypothesis proposed by Macphail is that differences in intelligent behavior thought to distinguish different species were likely attributed to differences in the context of the tasks being used. Once one corrects for differences in sensory input, motor output, and incentive, it is likely that all vertebrate animals have comparable intellectual abilities. In the present article I suggest a number of tests of this hypothesis with pigeons. In each case, the evidence suggests that either there is evidence for the cognitive (...) behavior, or the pigeons suffer from biases similar to those of humans. Thus, Macphail’s hypothesis offers a challenge to researchers to find the appropriate conditions to bring out in the animal the cognitive ability being tested. (shrink)

This series offers central philosophical treatises of Aquinas in new, state-of-the-art translations distinguished by their accuracy and use of clear and nontechnical modern vocabulary. Annotation and commentary accessible to undergraduates make the series an ideal vehicle for the study of Aquinas by readers approaching him from a variety of backgrounds and interests.

Cognitivism about trust says that it requires belief that the trusted is trustworthy; non-cognitivism denies this. At stake is how to make sense of the strong but competing intuitions that trust is an attitude that is evaluable both morally and rationally. In proposing that one's respect for another's agency may ground one's trusting beliefs, second-personal accounts provide a way to endorse both intuitions. They focus attention on the way that, in normal situations, it is the person whom I trust. My (...) task is to develop an account of the latter insight without the controversial theoretical commitments of the former. I propose a functional account for why the second and third-personal ‘systems’ operate not just in parallel, but in tandem, in support of a cognitivist account of trust. (shrink)

In the years since Enron corporate social responsibility, or “CSR,” has become a ubiquitous phenomenon in both research and business practice. CSR is used as an umbrella term to describe much of what is done in terms of ethics-related activities in firms around the globe to such an extent that some consider it a “tortured concept” (Godfrey and Hatch 2007, Journal of Business Ethics 70, 87–98). Addressing this skepticism, I argue in this article that the focus on CSR is indeed (...) problematic for three main reasons: (1) the term carries a lot of historical baggage – baggage that is not necessarily conducive to the clarity of the concept; (2) it is the object of increasing ethical instrumentalism; and (3) given the multiple ethical challenges that corporations face, and given the fact that the “social” responsibilities of business are but one set of corporate responsibilities, a suitable term would have to be more inclusive and integrative. I therefore suggests moving instead toward a sound definition of corporate integrity and aim in this article to develop a working definition by fleshing out “7 Cs” of integrity: commitment, conduct, content, context, consistency, coherence, and continuity. I then discuss how these 7 Cs impact our understanding of CSR or, more broadly, corporate responsibility in general. (shrink)

A new public philosophy began to emerge in the United States during the Progressive Era. Promoted by such intellectuals as John Dewey, William James, and the coUectivists of the New Republic magazine, it called for a citizenry trained in an experimental milieu, free of dogma and emancipated from sources of allegiance other than the new centralized democratic state then being forged. Catholics, however, neither capitulated to the new creed nor retreated into a self-righteous isolation. In a culture whose chief value (...) was pluralism they insisted on the uniqueness of the Church and the need for making value judgments based on a sound philosophy of man. (shrink)

This issue includes a number of papers on reproductive ethics, broadly construed. In a recent book, Anja Karnein proposed that embryos created in vitro should be offered up for adoption before being discarded or used in research;1 here Timothy Murphy offers a critical response . Elsewhere, Tak Chan and Stark & Delatycki debate the role of medical professionals in providing parentage determination. Chan argues that doctors are obliged to provide parentage tests when this is requested by parents, provided there is (...) a low risk that the child will be abandoned . Stark & Delatycki discuss some difficulties raised by the ‘risk of abandonment’ condition . Finally, papers by Kate Greasley and David Lang discuss the controversy surrounding the criminal prosecution of abortion doctor Kermit Gosnell. Greasley criticises the way in which some commentators capitalised on horror at Gosnell's extreme practices to advance more general anti-abortion objectives . Lang argues, against Greasley, that the dominant pro-life response to the case was neither self-contradictory nor intellectually dishonest .The issue is dominated, however, by discussions of ‘bioenhancement’ – the use of biomedical technologies to augment human capacities. A common criticism of bioenhancements is that they are anti-social: though they may benefit the user, they will have a negative effect on society-at-large. Such concerns are perhaps well placed in relation to the most obvious contemporary examples of bioenhancement: doping in sport, aesthetic medicine, and the use of stimulants to enhance examination performance. However, two varieties of bioenhancement discussed in this issue might be thought to have more positive social effects.David Shaw discusses the possible use of cognitive enhancing drugs to improve health outcomes in disadvantaged segments of society . Such enhancements might be thought to have desirable social …. (shrink)

The mathematician G.F.C. Griss is known for his program of negationless intuitionistic mathematics. Although Griss’s rejection of negation is regarded as characteristic of his philosophy, this is a consequence of an executability requirement that mental constructions presuppose agents’ executing corresponding mental activity. Restoring Griss’s executability requirement to a central role permits a more subtle characterization of the rejection of negation, according to which D. Nelson’s strong constructible negation is compatible with Griss’s principles. This exposes a ‘holographic’ theory of negation in (...) negationless mathematics, in which a full theory of negation is ‘flattened’ in a putatively negationless setting. (shrink)

Codes of ethics are directly aimed at behavioral control, but they also affect a company’s ethical culture, which in turn concerns compliance and ethical behavior. To positively influence a company’s ethical culture, employees must be familiar with its code of ethics, perceive that top management is committed to the code, and believe that their peers also comply with the code. The evidence on whether a code’s design affects a company’s ethical culture is limited. This study’s factorial survey experiment contributes to (...) this gap in two ways: first, it investigates whether a code’s design affects how easily the code can be learned and, therefore, contributes to code familiarity. Second, it examines how a code can convey expectations regarding top management’s commitment and peers’ behavior, both of which are part of ethical culture. The results indicate that a positive tone increases code familiarity, and a code signed by top managers sends a strong signal of their commitment to the code. Finally, various implications of the results for research and practice are discussed. (shrink)

Quantum mechanics has provided philosophers of science with many counterintuitive insights and interpretive puzzles, but little has been written about the role that time plays in the theory. One reason for this is the celebrated argument of Wolfgang Pauli against the inclusion of time as an observable of the theory, which has been seen as a demonstration that time may only enter the theory as a classical parameter. Against this orthodoxy I argue that there are good reasons to expect certain (...) kinds of 'time observables' to find a representation within quantum theory, including clock operators and event time operators, which provide predictions for the time at which a particular event occurs, such as the appearance of a dot on a luminescent screen. I contend that these time operators deserve full status as observables of the theory, and on reflection provide a uniquely compelling reason to expand the set of observables allowed by the standard formalism of quantum mechanics. In addition, I provide a novel association of event time operators with conditional probabilities, and propose a temporally extended form of quantum theory to better accommodate the time of an event as an observable quantity. This leads to a proposal to interpret quantum theory within an event ontology, inspired by Bertrand Russell's Analysis of Matter. On this basis I mount a defense of Russell's relational theory of time against a recent attack. (shrink)

As phenomenology rose to prominence at the beginning of the 20th century, several aestheticians tried to establish the Husserlian method of “phenomenological reduction” in the field of aesthetics. These ventures were met with resistance from psychological aesthetics, which was the predominant form of aesthetics in the German-speaking world at the time. This paper examines, first, practical attempts to apply the method of “phenomenological reduction” in aesthetics. Using Waldemar Conrad and Moritz Geiger as examples, I try to trace what aestheticians actually (...) did when they applied this method in their investigations. Secondly, I reconstruct the four central objections with which psychological aesthetics reacted to such attempts. I have identified four central counterarguments in the work of Johannes Volkelt and Oswald Külpe, who were among the most eminent critics of phenomenological aesthetics: the transcendental argument, the susceptibility-to-errors argument, the constructivism argument, and the non-normativity argument. Finally, I also discuss the refusal of psychological aesthetics to acknowledge that a genuine phenomenological method even existed and the consequences of this refusal. (shrink)

This paper will examine the topic of identity in Roman Catholicism from the perspective of topics contained in or absent from mission statements of 25 Catholic health care institutions. In particular, I will look at these from the perspective of social justice as well as how this and other topics such as human dignity, the sanctity of life, stewardship, pastoral care and the likelihood of mergers with other institutions will affect the healing ministry of Catholic health care providers. The article (...) will conclude that there are three key dimensions to Catholic health care: leadership in advocating reform of the current health care system, care for the marginalized and under-insured, and the provision of pastoral care in all institutions. (shrink)

Many of the problems studied in cognitive science are inductive problems, requiring people to evaluate hypotheses in the light of data. The key to solving these problems successfully is having the right inductive biases—assumptions about the world that make it possible to choose between hypotheses that are equally consistent with the observed data. This article explores a novel experimental method for identifying the biases that guide human inductive inferences. The idea behind this method is simple: This article uses the responses (...) produced by a participant on one trial to generate the stimuli that either they or another participant will see on the next. A formal analysis of this “iterated learning” procedure, based on the assumption that the learners are Bayesian agents, predicts that it should reveal the inductive biases of these learners, as expressed in a prior probability distribution over hypotheses. This article presents a series of experiments using stimuli based on a well-studied set of category structures, demonstrating that iterated learning can be used to reveal the inductive biases of human learners. (shrink)