MicroRNA‐10b regulates the renewal of spermatogonial stem cells through Kruppel‐like factor 4

MicroRNAs (miRs) are functionally important in spermatogenesis, which is the self‐renewal or differentiation of spermatogonial stem cells (SSCs). Here, we report a novel role for miR‐10b in regulating the self‐renewal of mouse SSCs. We showed that miR‐10b was highly expressed in mouse SSCs in vitro and enhanced SSC proliferation. Knockdown of miR‐10b significantly increased the apoptosis of SSCs compared with controls. Kruppel‐like factor 4 was found to be a target gene of miR‐10b in the enhancement of SSC proliferation. These findings further our understanding of the self‐renewal and differentiation of SSCs and provide a basis for the diagnosis, treatment, and prevention of male infertility.     

The Emergence of Stem Cell‐Based Brain Organoids: Trends and Challenges

Recent developments in 3D cultures exploiting the self‐organization ability of pluripotent stem cells have enabled the generation of powerful in vitro systems termed brain organoids. These 3D tissues recapitulate many aspects of human brain development and disorders occurring in vivo. When combined with improved differentiation methods, these in vitro systems allow the generation of more complex “assembloids,” which are able to reveal cell diversities, microcircuits, and cell–cell interactions within their 3D organization. Here, the ways in which human brain organoids have contributed to demystifying the complexities of brain development and modeling of developmental disorders is reviewed and discussed. Furthermore, challenging questions that are yet to be addressed by emerging brain organoid research are discussed.     

Receptor‐Free Signaling at Curved Cellular Membranes

Plasma membranes are subject to continuous deformations. Strikingly, some of these transient membrane undulations yield membrane‐associated signaling hubs that differ in composition and function, depending on membrane geometry and the availability of co‐factors. Here, recent advancements on this ubiquitous type of receptor‐independent signaling are reviewed, with a special focus on emerging concepts and technical challenges associated with studying these elusive signaling sites.     

Dual‐Tube Helmholtz Resonator‐Based Triboelectric Nanogenerator for Highly Efficient Harvesting of Acoustic Energy

An acoustic wave is a type of energy that is clean and abundant but almost totally unused because of its very low density. This study investigates a novel dual‐tube Helmholtz resonator‐based triboelectric nanogenerator (HR‐TENG) for highly efficient harvesting of acoustic energy. This HR‐TENG is composed of a Helmholtz resonant cavity, a metal film with evenly distributed acoustic holes, and a dielectric soft film with one side ink‐printed for electrode. Effects of resonant cavity structure, acoustic conditions, and film tension on the HR‐TENG performance are investigated systematically. By coupling the mechanisms of triboelectric nanogenerator and acoustic propagation, a theoretical guideline is provided for improving energy output and broadening the frequency band. Specifically, the present HR‐TENG generates the maximum acoustic sensitivity per unit area of 1.23 VPa^?1 cm^?2 and the maximum power density per unit sound pressure of 1.82 WPa^?1 m^?2, which are higher than the best results from the literature by 60 and 20%, respectively. In addition, the HR‐TENG may also serve as a self‐powered acoustic sensor.     

An ambiguity in Habermas’s argument against liberal eugenics

In his book The future of human nature, Jürgen Habermas argues against a scenario of liberal eugenics, in which parents are free to prenatally manipulate their children’s genetic constitution via germline interventions. In this paper, I draw attention to the fact that his species‐ethical line of argument is pervaded by a substantial ambiguity between an argument from actual intervention (AAI) and an argument from mere controllability (AMC). Whereas the first argument focuses on threats for the autonomy and equality of prenatally modified persons, the second argument takes all human beings, whether they have been modified or not, into account. Hence, when invoking Habermas in these debates, bioethicists need to consider carefully which argument they are referring to.     

Why do evolutionary systems stick to the edge of chaos

Summary  The long-term behaviour of dynamic systems can be classified in two different regimes, regular or chaotic, depending on the values of the control parameters, which are kept constant during the time evolution. Starting from slightly different initial conditions, a regular system converges to the same final trajectory, whereas a chaotic system follows two distinct trajectories exponentially diverging from each other. In spite of these differences, regular and chaotic systems share a common property: both arrive exponentially fast to their final destiny, becoming trapped there. In both cases one has finite transient times. This is not a profitable property in what concerns evolutionary strategies, where the eternal search for new forms, better than the current one, is imperative. That is why evolutionary dynamic systems tend to tune themselves in very particular situations in between regular and chaotic regimes. These particular situations present eternal transients, and the system actually never reaches its final destiny, preserving diversity. This feature allows the system to visit other regions of the space of possibilities, not only the tiny region covered by its final attractor.     

The lived experience of depression: a bottom-up review co-written by experts by experience and academics

We provide here the first bottom-up review of the lived experience of depression, co-written by experts by experience and academics. First-person accounts within and outside the medical field were screened and discussed in collaborative workshops involving numerous individuals with lived experience of depression, family members and carers, representing a global network of organizations. The material was enriched by phenomenologically informed perspectives and shared with all collaborators in a cloud-based system. The subjective world of depression was characterized by an altered experience of emotions and body (feeling overwhelmed by negative emotions, unable to experience positive emotions, stuck in a heavy aching body drained of energy, detached from the mind, the body and the world); an altered experience of the self (losing sense of purpose and existential hope, mismatch between the past and the depressed self, feeling painfully incarcerated, losing control over one's thoughts, losing the capacity to act on the world; feeling numb, empty, non-existent, dead, and dreaming of death as a possible escape route); and an altered experience of time (experiencing an alteration of vital biorhythms, an overwhelming past, a stagnation of the present, and the impossibility of the future). The experience of depression in the social and cultural context was characterized by altered interpersonal experiences (struggling with communication, feeling loneliness and estrangement, perceiving stigma and stereotypes), and varied across different cultures, ethnic or racial minorities, and genders. The subjective perception of recovery varied (feeling contrasting attitudes towards recovery, recognizing recovery as a journey, recognizing one's vulnerability and the need for professional help), as did the experience of receiving pharmacotherapy, psychotherapy, and social as well as physical health interventions. These findings can inform clinical practice, research and education. This journey in the lived experience of depression can also help us to understand the nature of our own emotions and feelings, what is to believe in something, what is to hope, and what is to be a living human being.     

Protocadherins branch out: Multiple roles in dendrite development

The proper formation of dendritic arbors is a critical step in neural circuit formation, and as such defects in arborization are associated with a variety of neurodevelopmental disorders. Among the best gene candidates are those encoding cell adhesion molecules, including members of the diverse cadherin superfamily characterized by distinctive, repeated adhesive domains in their extracellular regions. Protocadherins (Pcdhs) make up the largest group within this superfamily, encompassing over 80 genes, including the ∼60 genes of the α-, β-, and γ-Pcdh gene clusters and the non-clustered δ-Pcdh genes. An additional group includes the atypical cadherin genes encoding the giant Fat and Dachsous proteins and the 7-transmembrane cadherins. In this review we highlight the many roles that Pcdhs and atypical cadherins have been demonstrated to play in dendritogenesis, dendrite arborization, and dendritic spine regulation. Together, the published studies we discuss implicate these members of the cadherin superfamily as key regulators of dendrite development and function, and as potential therapeutic targets for future interventions in neurodevelopmental disorders.     

Fetal teratogenicity in a rhesus macaque (Macaca mulatta): Association with the chronic maternal treatment of amitriptyline

Amitriptyline is a tricyclic antidepressant commonly prescribed in humans for pain and sleep disorders and in non‐human primates for self‐injurious behaviors. Here, we report a clinical case on the teratogenic effect of maternal‐fetal amitriptyline exposure.