Testing foundations of quantum mechanics with photons

The foundational ideas of quantum mechanics continue to give rise to counterintuitive theories and physical effects that are in conflict with a classical description of Nature. Experiments with light at the single photon level have historically been at the forefront of tests of fundamental quantum theory and new developments in photonics engineering continue to enable new experiments. Here we review recent photonic experiments to test two foundational themes in quantum mechanics: wave-particle duality, central to recent complementarity and delayed-choice experiments; and Bell nonlocality where recent theoretical and technological advances have allowed all controversial loopholes to be separately addressed in different photonics experiments.Comment: 10 pages, 5 figures, published as a Nature Physics Insight review articl

Clusters of galaxies : observational properties of the diffuse radio emission

Clusters of galaxies, as the largest virialized systems in the Universe, are ideal laboratories to study the formation and evolution of cosmic structures...(abridged)... Most of the detailed knowledge of galaxy clusters has been obtained in recent years from the study of ICM through X-ray Astronomy. At the same time, radio observations have proved that the ICM is mixed with non-thermal components, i.e. highly relativistic particles and large-scale magnetic fields, detected through their synchrotron emission. The knowledge of the properties of these non-thermal ICM components has increased significantly, owing to sensitive radio images and to the development of theoretical models. Diffuse synchrotron radio emission in the central and peripheral cluster regions has been found in many clusters. Moreover large-scale magnetic fields appear to be present in all galaxy clusters, as derived from Rotation Measure (RM) studies. Non-thermal components are linked to the cluster X-ray properties, and to the cluster evolutionary stage, and are crucial for a comprehensive physical description of the intracluster medium. They play an important role in the cluster formation and evolution. We review here the observational properties of diffuse non-thermal sources detected in galaxy clusters: halos, relics and mini-halos. We discuss their classification and properties. We report published results up to date and obtain and discuss statistical properties. We present the properties of large-scale magnetic fields in clusters and in even larger structures: filaments connecting galaxy clusters. We summarize the current models of the origin of these cluster components, and outline the improvements that are expected in this area from future developments thanks to the new generation of radio telescopes.Comment: Accepted for the publication in The Astronomy and Astrophysics Review. 58 pages, 26 figure

Cervical Mucus Properties Stratify Risk for Preterm Birth

Background: Ascending infection from the colonized vagina to the normally sterile intrauterine cavity is a well-documented cause of preterm birth. The primary physical barrier to microbial ascension is the cervical canal, which is filled with a dense and protective mucus plug. Despite its central role in separating the vaginal from the intrauterine tract, the barrier properties of cervical mucus have not been studied in preterm birth. Methods and Findings: To study the protective function of the cervical mucus in preterm birth we performed a pilot case-control study to measure the viscoelasticity and permeability properties of mucus obtained from pregnant women at high-risk and low-risk for preterm birth. Using extensional and shear rheology we found that cervical mucus from women at high-risk for preterm birth was more extensible and forms significantly weaker gels compared to cervical mucus from women at low-risk of preterm birth. Moreover, permeability measurements using fluorescent microbeads show that high-risk mucus was more permeable compared with low-risk mucus. Conclusions: Our findings suggest that critical biophysical barrier properties of cervical mucus in women at high-risk for preterm birth are compromised compared to women with healthy pregnancy. We hypothesize that impaired barrier properties of cervical mucus could contribute to increased rates of intrauterine infection seen in women with preterm birth. We furthermore suggest that a robust association of spinnbarkeit and preterm birth could be an effectively exploited biomarker for preterm birth prediction.Massachusetts Institute of Technology. Charles E. Reed Faculty Initiative FundBurroughs Wellcome Fund (Preterm Birth Research Grant)National Science Foundation (U.S.). Graduate Research Fellowship Progra

The effects of juvenile stress on anxiety, cognitive bias and decision making in adulthood:a rat model

Stress experienced in childhood is associated with an increased risk of developing psychiatric disorders in adulthood. These disorders are particularly characterized by disturbances to emotional and cognitive processes, which are not currently fully modeled in animals. Assays of cognitive bias have recently been used with animals to give an indication of their emotional/cognitive state. We used a cognitive bias test, alongside a traditional measure of anxiety (elevated plus maze), to investigate the effects of juvenile stress (JS) on adulthood behaviour using a rodent model. During the cognitive bias test, animals were trained to discriminate between two reward bowls based on a stimulus (rough/smooth sandpaper) encountered before they reached the bowls. One stimulus (e.g. rough) was associated with a lower value reward than the other (e.g. smooth). Once rats were trained, their cognitive bias was explored through the presentation of an ambiguous stimulus (intermediate grade sandpaper): a rat was classed as optimistic if it chose the bowl ordinarily associated with the high value reward. JS animals were lighter than controls, exhibited increased anxiety-like behaviour in the elevated plus maze and were more optimistic in the cognitive bias test. This increased optimism may represent an optimal foraging strategy for these underweight animals. JS animals were also faster than controls to make a decision when presented with an ambiguous stimulus, suggesting altered decision making. These results demonstrate that stress in the juvenile phase can increase anxiety-like behaviour and alter cognitive bias and decision making in adulthood in a rat model

Parent perceptions of the quality of life of pet dogs living with neuro-typically developing and neuro-atypically developing children: an exploratory study

There is growing scientific and societal recognition of the role that pet dogs can play in healthy development of children; both those who are neuro-typically developing and those who live with a neuro-developmental disorder, such as autism or attention deficit hyperactivity disorder. However, little attention has been paid to how living with children positively and negatively affects quality of life of a pet dog. In this exploratory study we conducted semi-structured interviews with parents of neuro-typically developing children (n = 18) and those with a neuro-developmental disorder (n = 18) who owned a pet dog, until no new factors were identified. Living with children brought potentially positive benefits to the dog’s life including: imposition of a routine, participation in recreational activities and the development of a strong bond between the child and the dog. The importance of maintaining a routine was particularly prevalent in families with children with neuro-developmental disorders. Potential negative factors included having to cope with child meltdowns and tantrums, over stimulation from child visitors, harsh contact and rough and tumble play with the child. The regularity and intensity of meltdowns and tantrums was particularly evident in responses from parents with children with a neuro-developmental disorder. However, child visitors and rough play and contact were mentioned similarly across the groups. Protective factors included having a safe haven for the dog to escape to, parent’s awareness of stress signs and child education in dog-interaction. Parents were also asked to complete a stress response scale to provide an initial quantitative comparison of stress responses between dogs living with the two family-types. Parents with neuro-typically developing children more frequently observed their dog rapidly running away from a situation and less frequently observed their dog widening their eyes, than parents with children with a neuro-developmental disorder. We propose the development of a stress audit based on the findings reported here, to prevent potential dangerous situations, which may lead to dog bites and dog relinquishment and allow owners to maximise the benefits of dog ownership

The ‘Biophilic Organization’: An Integrative Metaphor for Corporate Sustainability

This paper proposes a new organizational metaphor, the ‘Biophilic Organization’, which aims to counter the bio-cultural disconnection of many organizations despite their espoused commitment to sustainability. This conceptual research draws on multiple disciplines such as evolutionary psychology and architecture to not only develop a diverse bio-cultural connection but to show how this connection tackles sustainability, in a holistic and systemic sense. Moreover, the paper takes an integrative view of sustainability, which effectively means that it embraces the different emergent tensions. Three specific tensions are explored: efficiency versus resilience, organizational versus personal agendas and isomorphism versus institutional change. In order to illustrate how the Biophilic Organization could potentially provide a synthesis strategy for such tensions, healthcare examples are drawn from the emerging fields of Biophilic Design in Singapore and Generative Design in the U.S.A. Finally, an example is provided which highlights how a Taoist cultural context has impacted on a business leader in China, to illustrative the significance of a transcendent belief system to such a bio-cultural narrative

QCD and strongly coupled gauge theories : challenges and perspectives

We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe

Exploring new physics frontiers through numerical relativity

The demand to obtain answers to highly complex problems within strong-field gravity has been met with significant progress in the numerical solution of Einstein's equations - along with some spectacular results - in various setups. We review techniques for solving Einstein's equations in generic spacetimes, focusing on fully nonlinear evolutions but also on how to benchmark those results with perturbative approaches. The results address problems in high-energy physics, holography, mathematical physics, fundamental physics, astrophysics and cosmology

HPV16 variant lineage, clinical stage, and survival in women with invasive cervical cancer

Background: HPV16 variants are associated with different risks for development of CIN3 and invasive cancer, although all are carcinogenic. The relationship of HPV 16 variants to cancer survival has not been studied. Methods: 155 HPV16-positive cervical cancers were categorized according to European and non-European variant patterns by DNA sequencing of the E6 open reading frame. Clinico-pathologic parameters and clinical outcome were collected by chart review and death registry data. Results: Of the 155 women (mean age 44.7 years; median follow-up 26.7 months), 85.2% harbored European variants while 14.8% had non-European sequences. HPV16 variants differed by histologic cell type (p = 0.03) and stage (1 vs. 2+; p = 0.03). Overall, 107 women (68.0%) were alive with no evidence of cancer, 42 (27.1%) died from cervical cancer, 2 (1.3%) were alive with cervical cancer, and 4 (2.6%) died of other causes. Death due to cervical cancer was associated with European variant status (p < 0.01). While 31% of women harboring tumors with European variants died from cervical cancer during follow-up, only 1 of 23 (4.4%) non-European cases died of cancer. The better survival for non-European cases was partly mediated by lower stage at diagnosis. Conclusions: Overall, invasive cervical cancers with non-European variants showed a less aggressive behavior than those with European variants. These findings should be replicated in a population with more non-European cases