Lifeboat Foundation

Special relativity prevents any object with mass travelling at the speed of light, and the principle of causality – the notion that the cause comes before the effect – is used to rule out the possibility of superluminal (faster-than-light) travel by light itself. However, a pulse of light can have more than one speed because it is made up of light of different wavelengths. The individual waves travel at their own phase velocity, while the pulse itself travels with the group velocity. In a vacuum all the phase velocities and the group velocity are the same. In a dispersive medium, however, they are different because the refractive index is a function of wavelength, which means that the different wavelengths travel at different speeds. Wang and colleagues report evidence for a negative group velocity of −310 c, where c (=300 million metres per second) is the speed of light in vacuum.

Their experimental set-up is remarkably similar to that used to slow light to a speed of just 17 metres per second last year. It relies on using two lasers and a magnetic field to prepare a gas of caesium atoms in an excited state. This state exhibits strong amplification or gain at two wavelengths, and highly anomalous dispersion – that is, the refractive index changes rapidly with wavelength – in the region between these two peaks.

Wang and colleagues begin by using a third continuous-wave laser to confirm that there are two peaks in the gain spectrum and that the refractive index does indeed change rapidly with wavelength in between. Next they send a 3.7-microsecond long laser pulse into the caesium cell, which is 6 centimetres long, and show that, at the correct wavelength, it emerges from the cell 62 nanoseconds sooner than would be expected if it had travelled at the speed of light. 62 nanoseconds might not sound like much, but since it should only take 0.2 nanoseconds for the pulse to pass through the cell, this means that the pulse has been travelling at 310 times the speed of light. Moreover, unlike previous superluminal experiments, the input and output pulse shapes are essentially the same.

Schizophrenia is a devastating psychiatric disorder characterized by positive, negative and cognitive symptoms. While aberrant dopamine system function is typically associated with the positive symptoms of the disease, it is thought that this is secondary to pathology in afferent regions. Indeed, schizophrenia patients show dysregulated activity in the hippocampus and prefrontal cortex, two regions known to regulate dopamine neuron activity. These deficits in hippocampal and prefrontal cortical function are thought to result, in part, from reductions in inhibitory interneuron function in these brain regions. Therefore, it has been hypothesized that restoring interneuron function in the hippocampus and/or prefrontal cortex may be an effective treatment strategy for schizophrenia. In this article, we will discuss the evidence for interneuron pathology in schizophrenia and review recent advances in our understanding of interneuron development. Finally, we will explore how these advances have allowed us to test the therapeutic value of interneuron transplants in multiple preclinical models of schizophrenia.

Schizophrenia is devastating psychiatric disorder that affects approximately 1% of the population¹. Positive symptoms, such as paranoia, grandiosity, delusions, and hallucinations, are often the most striking features of the disorder; however, schizophrenia patients also display characteristic negative and cognitive symptoms, which can be severely debilitating. Negative symptoms, such as blunted affect, emotional withdrawal, and social avoidance and cognitive symptoms, including disruptions in working memory, attentional deficits, disorganized thought, and cognitive inflexibility, can negatively influence social and occupational functioning and diminish quality of life^2–4. Currently prescribed antipsychotic medications, which act as antagonists at the dopamine D2 receptor⁵, have been somewhat effective in treating the positive symptoms of schizophrenia⁶.

Circa 2019 face_with_colon_three

Multipotent cells are critical to regenerative medicine and its associated deployment strategies. Localizing an abundant source of autologous, adult stem cells circumvents the immunological prohibitions of allogeneity and ethical dilemmas of embryologic stem cells, respectively. Classically, these cells have been described as mesenchymal stem cells (MSCs). In this chapter, we characterize adipose tissue as a unique source of MSCs because of its ubiquity, redundancy, and procurability. Specifically, lipoaspirates can be minimally processed to provide a heterogenous, cell-dense isolate – the stromal vascular fraction (SVF) – composed of terminally differentiated vessel-associated cell lines as well as putative progenitor cells. These cells have been cultured and expanded, giving rise to a dynamic cell line termed adipose-derived stromal cells (ASCs). SVF and ASC cell isolates are often administered by standard clinical routes including parenteral, topical application, and local injection in the clinical translational studies of cardiovascular ischemia, neurological injury, rheumatologic and orthopedic disease as well as advanced wound care and tissue engineering. These clinical applications raise safety concerns specific to administration, sequestration, and tumor growth augmentation. Further studies SVF and ASC cells are necessary to realize their potential in a regenerative medicine capacity.

Wildlife officials hoped it was not capable of killing native species in the United States, but it’s causing die-offs throughout the southwest.

The interplay between the commensal microbiota and the mammalian immune system development and function includes multifold interactions in homeostasis and disease. The microbiome plays critical roles in the training and development of major components of the host’s innate and adaptive immune system, while the immune system orchestrates the maintenance of key features of host-microbe symbiosis. In a genetically susceptible host, imbalances in microbiota-immunity interactions under defined environmental contexts are believed to contribute to the pathogenesis of a multitude of immune-mediated disorders. Here, we review features of microbiome-immunity crosstalk and their roles in health and disease, while providing examples of molecular mechanisms orchestrating these interactions in the intestine and extra-intestinal organs. We highlight aspects of the current knowledge, challenges and limitations in achieving causal understanding of host immune-microbiome interactions, as well as their impact on immune-mediated diseases, and discuss how these insights may translate towards future development of microbiome-targeted therapeutic interventions.

Researchers have developed a new strategy that uses optical coherence tomography (OCT) to acquire both the surface and underlying details of impressionist style oil paintings. This information can be used to create detailed 3D reconstructions to enhance the viewing experience and offer a way for the visually impaired to experience paintings.

“Visitors to art museums can’t closely examine paintings and see the artists’ techniques because of security and conservation concerns,” said research team leader Yi Yang from Penn State Abington. “Our new technology can create 3D reconstructions that can be rotated and magnified to view details such as brushstrokes. This would be especially useful for online classes.”

Yang and colleagues from Penn State University Park and New Jersey Institute of Technology report the new technique in the Optical Society journal Applied Optics. The research team brought together specialists in art history and conservation with electrical and optical engineers.

Researchers see both benefits and risks in the company’s increasing power. It has lowered the cost of spaceflight through innovations such as reusable stages and fairings, saving NASA money. With its outsize capacity, Starship could cheaply put large telescopes in orbit and heavy science experiments on moons and planets. Yet SpaceX, with a fast-and-loose Silicon Valley mindset, has overlooked the potential for its technologies to contaminate night skies and pristine planets. Some worry the company, led by brazen billionaire Elon Musk, could jeopardize NASA’s long-standing culture of safety. “NASA tries to model everything to the nth degree,” says David Todd, an analyst at Seradata, which tracks launches and satellites. “SpaceX works on the basis of ‘test it until it breaks.’”.

First commercial crew flight deepens ties between company and space agency.

After the 1980 eruption, a glacier formed in the shadows inside the crater. Scientists—and our photographer—have explored its icy depths.

Simulators that can rapidly test trillions of options would accelerate the slow and costly process of human clinical trials.