A fundamental problem for the evolution of pregnancy, the most specialized form of parental investment among vertebrates, is the rejection of the nonself-embryo. Mammals achieve immunological tolerance by down-regulating both major histocompatibility complex pathways (MHC I and II). Although pregnancy has evolved multiple times independently among vertebrates, knowledge of associated...
12h
Seasonal changes in the environment lead to depression-like behaviors in humans and animals. The underlying mechanisms, however, are unknown. We observed decreased sociability and increased anxiety-like behavior in medaka fish exposed to winter-like conditions. Whole brain metabolomic analysis revealed seasonal changes in 68 metabolites, including neurotransmitters and antioxidants associated with...
12h
Yeast strains with low levels of the replicative DNA polymerases (alpha, delta, and epsilon) have high levels of chromosome deletions, duplications, and translocations. By examining the patterns of mutations induced in strains with low levels of DNA polymerase by the human protein APOBEC3B (a protein that deaminates cytosine in single-stranded...
12h
Resolution of intestinal inflammation and wound repair are active processes that mediate epithelial healing at mucosal surfaces. Lipid molecules referred to as specialized proresolving mediators (SPMs) play an important role in the restorative response. Resolvin E1 (RvE1), a SPM derived from omega-3 fatty acids, has been reported to dampen intestinal...
12h
The accelerating pace of genome sequencing throughout the tree of life is driving the need for improved unsupervised annotation of genome components such as transposable elements (TEs). Because the types and sequences of TEs are highly variable across species, automated TE discovery and annotation are challenging and time-consuming tasks. A...
12h
Amacrine cells are a diverse population of interneurons in the retina that play a critical role in extracting complex features of the visual world and shaping the receptive fields of retinal output neurons (ganglion cells). While much of the computational power of amacrine cells is believed to arise from the...
12h
Building a brain of the proper size and structure requires neural stem cells (NSCs) to divide with tight temporal and spatial control to produce different daughter cell types in proper numbers and sequence. Mammalian NSCs in the embryonic cortex must maintain their polarized epithelial structure as they undergo both early...
12h
Bats are reservoirs of emerging viruses that are highly pathogenic to other mammals, including humans. Despite the diversity and abundance of bat viruses, to date they have not been shown to harbor exogenous retroviruses. Here we report the discovery and characterization of a group of koala retrovirus-related (KoRV-related) gammaretroviruses in...
12h
Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that colonizes the gastrointestinal tract and has evolved intricate mechanisms to sense and respond to the host environment. Upon the sensation of chemical and physical cues specific to the host’s intestinal environment, locus of enterocyte effacement (LEE)-encoded virulence genes are activated and...
12h
P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric, mucin-like, 120-kDa glycoprotein that binds to P-, E-, and L-selectins. PSGL-1 is expressed primarily on the surface of lymphoid and myeloid cells and is up-regulated during inflammation to mediate leukocyte tethering and rolling on the surface of endothelium for migration into inflamed tissues....
12h
Understanding how bacteria colonize surfaces and regulate cell-cycle progression in response to cellular adhesion is of fundamental importance. Here, we use transposon sequencing in conjunction with fluorescence resonance energy transfer (FRET) microscopy to uncover the molecular mechanism for how surface sensing drives cell-cycle initiation in Caulobacter crescentus. We identify the...
12h
Remarkable progress has come from whole-brain models linking anatomy and function. Paradoxically, it is not clear how a neuronal dynamical system running in the fixed human anatomical connectome can give rise to the rich changes in the functional repertoire associated with human brain function, which is impossible to explain through...
12h
Inner Workings: Microbiota munch on medications, causing big effects on drug activity [Microbiology]
Millions of patients with Parkinson’s disease rely on the drug Levodopa for relief from tremors, slowed movement, and other motor symptoms. But many patients experience side effects such as cardiac arrhythmias, nausea, and gastrointestinal problems. Levodopa’s side effects and benefits vary widely among patients. Those puzzling disparities, it turns out,...
12h
The blood–brain barrier (BBB) presents a significant challenge for treating brain disorders. The hippocampus is a key target for novel therapeutics, playing an important role in Alzheimer’s disease (AD), epilepsy, and depression. Preclinical studies have shown that magnetic resonance (MR)-guided low-intensity focused ultrasound (FUS) can reversibly open the BBB and...
12h
Cavitation is the sudden, unstable expansion of a void or bubble within a liquid or solid subjected to a negative hydrostatic stress. While predominantly studied in fluids, cavitation is also an origin of damage in soft materials, including biological tissues. Examples of cavitation in fluids and soft solids are shown...
12h
We present a platform for parallel production of standalone, untethered electronic sensors that are truly microscopic, i.e., smaller than the resolution of the naked eye. This platform heterogeneously integrates silicon electronics and inorganic microlight emitting diodes (LEDs) into a 100-μm-scale package that is powered by and communicates with light. The...
12h
Mean field games (MFG) and mean field control (MFC) are critical classes of multiagent models for the efficient analysis of massive populations of interacting agents. Their areas of application span topics in economics, finance, game theory, industrial engineering, crowd motion, and more. In this paper, we provide a flexible machine...
12h
Phosphoinositides (PIs), the phosphorylated derivatives of the membrane glycerophospholipid phosphatidylinositol (PtdIns), are minor constituents of eukaryotic cell membranes that play an important role as signaling molecules (1). The inositol ring can be phosphorylated at three positions and the seven resulting phosphorylated forms are dynamically interconverted and differentially distributed among cellular...
12h
The abilities of humans to produce and store food have been key components in theories that explain how and why societies flourished and developed complex socioeconomic systems over time. Archaeological evidence shows that the transition from hunting/gathering/foraging to the purposeful cultivation of plants and domestication of animals was an important...
12h
Host responses to bacterial infection are protective, yet without timely resolution they can lead to uncontrolled infection, with systemic engagement and multiple organ failure. In PNAS, Sekheri et al. (1) report the property of specific lipid mediators to counteract the delay tactics of bacterial DNA released from proliferating or dying...
12h
Mammalian genomes are replete with transposable elements (TEs): parasitic genetic sequences that can replicate to high copy numbers within host genomes (1). TEs are widely recognized as a potent source of cell type- and context-specific regulatory elements (2, 3). In PNAS, Ye et al. (4) analyze chromatin profiling data from...
12h
In 1965, engineer Gordon Moore predicted that the number of transistors in an integrated circuit would double every two years. This prediction, known as Moore’s Law, has been proven accurate and spurred semiconductor research toward miniaturization. Moore’s Law, however, is starting to plateau. According to Cornell University physicist and National...
12h
Frank Press, 19th president of the National Academy of Sciences, died on Wednesday, January 29, 2020, at his home in Chapel Hill, North Carolina, at the age of 95. His career spanned the golden age of postwar science, and its arc took him to the highest levels of leadership in...
12h
Ecologists accept the Forage Maturation Hypothesis (FMH) that young plants optimize food quality by balancing nutrient and biomass availability (1). The Green Wave Hypothesis (GWH) applies the FMH to migrating herbivores by linking the timing, pace, and extent of migrations to waves of new plant growth (2, 3). The GWH...
12h
Geremia et al. (1) analyze a range of data on bison movement, remotely sensed Normalized Difference Vegetation Index, and plant dietary quality at Yellowstone National Park to test tenets of the Green Wave Hypothesis (GWH). The authors conclude that bison migrate in concert with plant phenological development along elevational gradients...
12h
We are aware of several definitions of kinship terminology. We follow the meaning used by Levi-Strauss (1). In our paper (2), we state explicitly what each term means. The incest taboo has both cultural (symbolic) and biological implications. As stated (2), we are interested in the former—“a cultural marriage rule...
12h
The simulation model presented in ref. 1 requires correct usage of kinship concepts. However, the two kinship concepts central to the model, the incest taboo and the clan form of social organization, are incorrectly presented. The authors incorrectly consider the incest taboo to express preference for marriages between different social...
12h
The alfalfa looper moth, Autographa californica, is a nondescript grayish brown moth first described by German lepidopterist Adolph Speyer in 1875 (1) and then reclassified by American entomologist Rodrigues Ottolengui (2). Neither the moth’s scientific name nor its common name is particularly descriptive; its range includes not just California but...
12h
Evolution of male pregnancy and immune remodeling Seahorses (Hippocampus abdominalis) swimming in an aquarium. Image credit: Sarah Kaehlert (GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany). In vertebrates, a developing embryo must avoid being recognized as foreign tissue by an immune system attuned to attack foreign antigens. Olivia Roth...
12h
Deliberate accountability has arrived in the medical arena, producing an age of reward for measured performance and belief in publicising metrics to ensure clarity, with winning defined as hitting targets, whereby staff are incentivised by arbitrary objectives. Finite game theory declares that players are known, rules are fixed and the objective agreed upon, but infinite game theory asserts that players are both known and unknown, rules are changeable, and the objective is to perpetuate the game;...
13h
CaseA 30-year-old woman presented with left-sided dull chest pain, productive cough and weight loss for 2 years. She denied fever, dyspnoea, night sweats or contact with patients afflicted by tuberculosis. Initial sputum workup was negative for tubercular, bacterial and fungal aetiologies, and a chest X-ray was unremarkable. CT scan of the lung revealed a large thick walled cyst in the left lower lobe, without any internal contents or similar lesions in other organs such as the liver (figure 1A)....
13h
IntroductionTaster weeks were introduced to give newly qualified doctors (foundation doctors) an opportunity to experience a wider variety of specialties.1 Foundation doctors have the opportunity to experience up to six specialties as part of their 2-year training, with restrictions to include at least one medical specialty, one surgical specialty and one specialty based in the community. As there are over 60 specialties and 30 subspecialties,2 some foundation doctors may not have the opportunity...
13h
More by accident than by design, a special themed issue on infectious disease in the Postgraduate Medical Journal was planned last year but comes out in this annus horribilis overshadowed by covid-19. Although the Postgraduate Medical Journal champions many themes of contemporary relevance and significance, including equal opportunity,1 gender equality2 and burn-out,3 it has also been receiving many manuscripts and images related to infectious disease. Therefore, this is a good moment to focus on...
13h
A 73-year-old man with type 2 diabetes and paroxysmal atrial fibrillation was admitted to our hospital with nausea, numbness in both lower legs, frequent falls and difficulty in speaking that had been present for 7 days. Two months before presentation, he underwent total gastrectomy for advanced gastric cancer, which was complicated by an intra-abdominal abscess, for which he had been administered oral levofloxacin (500 mg daily) and metronidazole (500 mg three times daily) for 1 month (total dose...
13h
The world watched in apathy as China struggled with rising numbers of the coronavirus, which took place in Wuhan, China, in early December 2019.1 Little did they know how an innocent encounter with a bat would bring the world to its knees, leading to a global pandemic in just 2 months. An alarming level of concern emerged when cases outside China revealed an appalling 13-fold rise in less than 2 weeks, urging the pandemic siren by WHO.This became the biggest challenge for the healthcare personnel...
13h
President John F. Kennedy (JFK) had a complex medical history that is now thought to be an autoimmune polyglandular syndrome type 2 with Addison’s disease and hypothyroidism. He also had gastrointestinal symptoms from adolescence, which now fit well with coeliac disease. In addition, he had a chronic back problem, which contributed to a chronic pain syndrome. This review looks at JFK’s various diseases and focusses on the history of coeliac disease, as well as its presentation. JFK’s Irish ancestry...
1d
Abstract Purpose To evaluate the impact of blended learning using a combination of educational resources (flipped classroom and short videos) on medical students’ (MSs) for radiology learning. Material and methods A cohort of 353 MSs from 2015 to 2018 was prospectively evaluated. MSs were assigned to four groups (high, high-intermediate, low-intermediate,...
13h
Abstract Background The paper covers modern approaches to the evaluation of neoplastic processes with diffusion-weighted imaging (DWI) and proposes a physical model for monitoring the primary quantitative parameters of DWI and quality assurance. Models of hindered and restricted diffusion are studied. Material and method To simulate hindered...
16h
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