A repeating fast radio burst source localized to a nearby spiral galaxy.

Fast radio bursts (FRBs) are brief, bright, extragalactic radio flashes1,2. Their physical origin remains unknown, but dozens of possible models have been postulated3. Some FRB sources exhibit repeat bursts4-7. Although over a hundred FRB sources have been discovered8, only four have been localized and associated with a host galaxy9-12, and just one of these four is known to emit repeating FRBs9. The properties of the host galaxies, and the local environments of FRBs, could provide important clues about their physical origins. The first known repeating FRB, however, was localized to a low-metallicity, irregular dwarf galaxy, and the apparently non-repeating sources were localized to higher-metallicity, massive elliptical or star-forming galaxies, suggesting that perhaps the repeating and apparently non-repeating sources could have distinct physical origins. Here we report the precise localization of a second repeating FRB source6, FRB 180916.J0158+65, to a star-forming region in a nearby (redshift 0.0337 ± 0.0002) massive spiral galaxy, whose properties and proximity distinguish it from all known hosts. The lack of both a comparably luminous persistent radio counterpart and a high Faraday rotation measure6 further distinguish the local environment of FRB 180916.J0158+65 from that of the single previously localized repeating FRB source, FRB 121102. This suggests that repeating FRBs may have a wide range of luminosities, and originate from diverse host galaxies and local environments.

Detection of CMB-Cluster Lensing using Polarization Data from SPTpol.

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500 deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.8σ. The mean stacked mass of the selected sample is found to be (1.43±0.40)×10^{14}M_{⊙} which is in good agreement with optical weak lensing based estimates using DES data and CMB-lensing based estimates using SPTpol temperature data. This measurement is a key first step for cluster cosmology with future low-noise CMB surveys, like CMB-S4, for which CMB polarization will be the primary channel for cluster lensing measurements.

Dusty starburst galaxies in the early Universe as revealed by gravitational lensing.

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

A massive, cooling-flow-induced starburst in the core of a luminous cluster of galaxies.

In the cores of some clusters of galaxies the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime, leading to continuous 'cooling flows' of gas sinking towards the cluster centre, yet no such cooling flow has been observed. The low observed star-formation rates and cool gas masses for these 'cool-core' clusters suggest that much of the cooling must be offset by feedback to prevent the formation of a runaway cooling flow. Here we report X-ray, optical and infrared observations of the galaxy cluster SPT-CLJ2344-4243 (ref. 11) at redshift z = 0.596. These observations reveal an exceptionally luminous (8.2 × 10(45) erg s(-1)) galaxy cluster that hosts an extremely strong cooling flow (around 3,820 solar masses a year). Further, the central galaxy in this cluster appears to be experiencing a massive starburst (formation of around 740 solar masses a year), which suggests that the feedback source responsible for preventing runaway cooling in nearby cool-core clusters may not yet be fully established in SPT-CLJ2344-4243. This large star-formation rate implies that a significant fraction of the stars in the central galaxy of this cluster may form through accretion of the intracluster medium, rather than (as is currently thought) assembling entirely via mergers.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment.

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope.

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

The gene for familial polyposis coli maps to the long arm of chromosome 5.

The inherited genetic defect in adenomatous polyposis has been localized to a small region on the long arm of chromosome 5. Sixteen DNA marker loci were used to construct a linkage map of the chromosome. When five kindreds segregating a gene for adenomatous polyposis coli were characterized with a number of the markers, significant linkage was found between one marker and the disease gene. Linkage analysis determined the location of the defective gene within a primary genetic map of chromosome 5.

The genetics of isolated and syndromic clubfoot.

PURPOSE: Congenital clubfoot is a serious birth defect that affects nearly 0.1% of all births. Though there is strong evidence for a genetic basis of isolated clubfoot, aside from a handful of associations, much of the heritability remains unexplained. METHODS: By systematically examining the genes involved in syndromic clubfoot, we may find new candidate genes and pathways to investigate in isolated clubfoot. RESULTS: In addition to the expected enrichment of extracellular matrix and transforming growth factor beta (TGF-ß) signalling genes, we find many genes involved in syndromic clubfoot encode peroxisomal matrix proteins, as well as enzymes necessary for sulfation of proteoglycans, an important part of connective tissue. Further, the association of Filamin B with isolated clubfoot as well as syndromic clubfoot is an encouraging finding. CONCLUSION: We should examine these categories for enrichment in isolated clubfoot patients to increase our understanding of the underlying biology and pathophysiology of this deformity. Understanding the spectrum of syndromes that have clubfoot as a feature enables a better understanding of the underlying pathophysiology of the disorder and directs future genetic screening efforts toward certain genes and genetic pathways. LEVEL OF EVIDENCE: V.

dgq: a drosophila gene encoding a visual system-specific G alpha molecule.

We describe the isolation and preliminary characterization of a new G alpha gene (dgq) in Drosophila. The dgq gene is differentially spliced, yielding two putative proteins, both of which contain guanine nucleotide binding and hydrolysis domains and share 50% identity with transducins and other G proteins. These proteins represent a new class of G alpha subunits because they lack both high amino acid identity with other G alpha proteins and the pertussis toxin ADP ribosylation site. The dgq mRNA is detected by RNA-RNA Northern hybridization in wild-type heads but not in wild-type bodies or in the mutant eyes absent heads. Tissue in situ hybridization detects dgq expression only in the retina and ocellus of the adult head, making it a prime candidate for encoding the Drosophila transducin analog, the G protein required for phototransduction.

South Pole Telescope optics.

The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

Folded fabric tunes rock deformation and failure mode in the upper crust.

The micro-mechanisms of brittle failure affect the bulk mechanical behaviour and permeability of crustal rocks. In low-porosity crystalline rocks, these mechanisms are related to mineralogy and fabric anisotropy, while confining pressure, temperature and strain rates regulate the transition from brittle to ductile behaviour. However, the effects of folded anisotropic fabrics, widespread in orogenic settings, on the mechanical behaviour of crustal rocks are largely unknown. Here we explore the deformation and failure behaviour of a representative folded gneiss, by combining the results of triaxial deformation experiments carried out while monitoring microseismicity with microstructural and damage proxies analyses. We show that folded crystalline rocks in upper crustal conditions exhibit dramatic strength heterogeneity and contrasting failure modes at identical confining pressure and room temperature, depending on the geometrical relationships between stress and two different anisotropies associated to the folded rock fabric. These anisotropies modulate the competition among quartz- and mica-dominated microscopic damage processes, resulting in transitional brittle to semi-brittle modes under P and T much lower than expected. This has significant implications on scales relevant to seismicity, energy resources, engineering applications and geohazards.

Production of the cytokines interleukin 1 and 6 by murine brain microvessel endothelium and smooth muscle pericytes.

Murine brain microvessel endothelial cells and smooth muscle/pericytes (SM/P) cells were cultured from newborn BALB/c (normal strain) and SJL/j (autoimmune-prone strain) mice. These cells were evaluated for their ability to produce interleukin (IL)-1 and IL-6 cytokines. The expression of mRNA for IL-1 and IL-6 was shown in highly purified BALB/c endothelial cells and SM/P cells using polymerase chain reaction with specific primers for IL-1 alpha, IL-1 beta and IL-6. IL-6 but not IL-1 mRNA was detected in unstimulated SJL/j brain microvessel cells. The presence of IL-1 and IL-6 mRNA in the BALB/c brain microvessel endothelial cells and SM/P was confirmed by in situ hybridization. By D10.G4.1 assay, unstimulated BALB/c endothelial cells were shown to produce active IL-1 to a higher degree than SM/P. By B9 bioassay, a low amount of active IL-6 was detected in the supernatant of endothelial cells and SM/P. The production of IL-1 and IL-6 in the bioassays was upregulated by lipopolysaccharide (LPS) activation of the cells in a time- and dose-dependent way. IL-6 production was also shown to be upregulated by IL-1 beta activation of the cells. Brain microvessel endothelial cells of SJL/j origin released equivalent amounts of IL-6 compared to endothelial cells of BALB/c origin. However, the production of IL-6 was markedly higher in SM/P of SJL/j origin than in those of BALB/c origin. These observations, together with our previous data showing that brain microvessel SM/P cells produce GM-CSF, emphasize the possibility for active participation of brain microvasculature SM/P as well as endothelium in inflammatory reactions of the central nervous system.

Comparison of nucleotide sequences among hantaviruses belonging to the same serotype: an analysis of amplified DNA by thermal cycle sequencing.

The hantavirus genus, belonging to the bunyaviridae family, is comprised of at least four serologically distinct types: Hantaan, Seoul, Puumala and Prospect Hill. Previously, we reported the use of the polymerase chain reaction (PCR) for grouping hantavirus isolates by using four sets of primers specific to each serotype. Our PCR typing results agreed with those of serological typing. The present study makes use of thermal cycle sequencing to sequence PCR-amplified DNA products in order to determine the level of similarity among members of the same serotype. We show that members of Hantaan and Seoul serotypes are over 92% homologous, irrespective of their host and geographical origin. Puumala sequences show a degree of homology ranging from 80 to 98%. Despite the variation in sequence at the nucleotide level, amino acids show an even higher level of conservation.

The estrous cycle affects pseudorabies virus (PRV) infection of the CNS.

Previous work had suggested that mucosal immunity may be affected by the stage of the estrous cycle. Here, susceptibility to a neurotropic virus infection at different stages of the estrous cycle was assessed in a rodent model after direct injection of the virus into visceral organs. In the first two experiments, female Sprague-Dawley rats were infected with pseudorabies virus (PRV, Bartha's K-strain) by injection into either the cervix or the kidney after monitoring their estrous cycle. After either 4- or 5-day survival period post-infection, the rats were euthanized by transcardially perfusion and peripheral and central nervous system tissues were removed for immunocytochemical staining. The number of infected neurons was counted in various regions. Statistical analysis revealed that: (1) the number of infected cells in the sympathetic or parasympathetic ganglion, or the dorsal root ganglia was not affected regardless of the stage of the estrous cycle after cervix injection with PRV; (2) in contrast, the number of infected neurons in the spinal cord was affected significantly by the stage of the estrous cycle during viral infection of the cervix; (3) after kidney infection, the number of infected neurons found within the spinal cord or dorsal root ganglia varied significantly across the estrous cycle. In both cases, animals infected in proestrus or estrus had fewer infected neurons than animals infected in diestrus I or diestrus II (proestrous and estrous animals had less than 20% of infected cells found in diestrus I or diestrus II rats). In the third experiment, older, persistent estrous or persistent diestrous rats were infected by kidney injection and given a 4-day survival period, prior to virus isolation from lower thoracic spinal cord. Animals in persistent estrous had significantly less virus per gram of tissue than the persistent diestrous rats. These data suggest that the CNS of animals in proestrus or estrus is less susceptible to PRV infection compared to animals in either diestrus I or diestrus II. Because estrogen replacement therapy is known to restore some immune functions during reproductive ageing, it is speculated that plasma estrogen levels modulate the central nervous system's susceptibility to viral infections.

Localization of dominantly inherited isolated triphalangeal thumb to chromosomal region 7q36.

Triphalangeal thumb is an autosomal dominantly inherited form of abnormal preaxial skeletal development. In most families, however, the triphalangeal thumb phenotype coexists with a spectrum of limb deformities, including polydactyly and syndactyly. We describe two Iowa kindreds with triphalangeal thumb. In one family, with nine affected members, triphalangeal thumb was the only manifestation of limb deformity. We performed linkage analysis on both pedigrees, demonstrating a maximum LOD score of 6.23 with marker D7S559 on chromosome 7q36. This corresponds to a previous study of a candidate region of 450 kb in which data from several families with preaxial polydactyly were employed. Further analysis of the unique family with isolated triphalangeal thumb in the current study may demonstrate allelic variability of the gene involved in these disorders.

A noninvasive, reattachable skull fiducial marker system. Technical note.

As computer-interactive technologies become more widely used in neurosurgery, radiology, and radiation therapy, the need for an optimum skull fiducial marker system increases. In the past, intracranial localization methods required precisely machined metal frames and rigid pin fixation to the skull. Recently, this function has been performed using "frameless" computer-based systems that calculate brain position relative to a series of external reference points, the most accurate of which are screwed directly into the skull. A penetrating fiducial marker system, however, is not well suited for applications requiring multiple volume registrations over an extended time period. We describe a new skull fiducial marker system that attaches to the maxillary teeth and can be used repeatedly on different occasions. A curved bar, known as a Banana Bar (BB) extends backward from a custom mouthpiece around the side of the patient's head; the bar contains sites of attachment for screw-in radiographic fiducial markers. Repositioning accuracy was quantitated using a photographic technique. A BB prototype was constructed and tested in three subjects. The BB weighs less than 100 g and can be comfortably held in position for up to 30 minutes. It takes less than 1 minute to screw in the mouthpiece and only seconds to secure the BB to the teeth. One hundred twenty photographic measurements were analyzed from 60 repositionings over a minimum 3-week period. Standard deviations for the measurement series ranged from 0.29 to 0.86 mm. Results suggest that the BB may be an inexpensive, efficient, and accurate method for providing the external reference points needed for a wide range of emerging computer-interactive applications.

Infantile and juvenile scoliosis.

The diagnosis and treatment of scoliosis in the infantile and juvenile age groups is a challenging and demanding endeavor. The diagnosis must be firmly established. Once a deformity has proven to be progressive, surgical intervention will likely be necessary because orthotic treatment is less effective in these cases. The surgeon is then faced with the dilemma of deciding on the most appropriate surgical treatment.

Osteoporosis: the increasing role of the orthopaedist.

Osteoporosis is an ever-increasing problem as our population ages. However, it is also to a large extent a preventable problem. The orthopaedist now has the ability to determine bone mass, the rate of turnover, and the fracture risk. Skeletal bone mass can be evaluated with DXA; the rate of bone resorption can be determined by assessment of collagen-degradation urinary products; and the weight status, fracture history, and history of smoking can be used to predict the fracture risk in individual patients. The orthopaedic physician also needs to take an active role in advising their younger patients about achieving peak bone mass. All individuals should follow a program that includes adequate calcium replacement, 400 to 800 units of vitamin D, appropriate exercise, avoidance of significant weight loss, and cessation of smoking. At menopause, women should evaluate their risk factors and consider the use of estrogen not only for its skeletal benefits but also for its nonosseous effects. In patients with contraindications or an aversion to hormone therapy, bone densitometry should be performed to determine risks before expensive nonhormonal treatment is initiated. Additional studies such as measurement of collagen degradation products will help establish whether the patient's resorptive rate is high or stable. If the bone mass is 2.5 SDs below normal peak or if there is an increase in resorption, use of either estrogen, bisphosphontes, or calcitonin may be appropriate. If there is evidence of low-turnover osteoporosis with decreased osteoblast formation, sodium fluoride should be considered. Two thirds of the cost of osteoporosis in the United States is due to hip fractures. The orthopaedist is the primary physician who comes in contact with these fracture patients. It is therefore his or her responsibility to become knowledgeable about the treatment and prevention of osteoporosis. The bisphosphonates, hormones, and calcitonin provide predictable restoration of bone mass and significantly decrease the rate of osteoporotic fractures.

Diabetic muscle infarction.

Diabetic muscle infarction is a rare complication of diabetes mellitus that is not clearly defined in the orthopaedic literature. This study is a descriptive case series of 7 new cases of diabetic muscle infarction and 55 previously reported cases in the literature. In the majority of patients, diabetic muscle infarction presents as a localized, exquisitely painful swelling and limited range of motion of the lower extremity. No cases affecting the muscles of the upper extremity have been observed. The onset is usually acute, persists for several weeks, and resolves spontaneously over several weeks to months without the need for intervention. Diabetic muscle infarction is a condition that should be considered in the differential diagnosis of any diabetic patient with lower extremity pain and swelling without systemic signs of infection. Magnetic resonance imaging is sensitive and specific enough to make the diagnosis. Muscle biopsy and surgical irrigation and debridement are not recommended since they are associated with complications. Pain management and activity restriction in the acute phase followed by gentle physical therapy is the treatment of choice. Recurrences in the same or opposite limb are common. Although the short-term prognosis is very good and the majority of cases resolve spontaneously, the long-term survival is uncertain in this patient population.