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.

A direct localization of a fast radio burst and its host.

Fast radio bursts are astronomical radio flashes of unknown physical nature with durations of milliseconds. Their dispersive arrival times suggest an extragalactic origin and imply radio luminosities that are orders of magnitude larger than those of all known short-duration radio transients. So far all fast radio bursts have been detected with large single-dish telescopes with arcminute localizations, and attempts to identify their counterparts (source or host galaxy) have relied on the contemporaneous variability of field sources or the presence of peculiar field stars or galaxies. These attempts have not resulted in an unambiguous association with a host or multi-wavelength counterpart. Here we report the subarcsecond localization of the fast radio burst FRB 121102, the only known repeating burst source, using high-time-resolution radio interferometric observations that directly image the bursts. Our precise localization reveals that FRB 121102 originates within 100 milliarcseconds of a faint 180-microJansky persistent radio source with a continuum spectrum that is consistent with non-thermal emission, and a faint (twenty-fifth magnitude) optical counterpart. The flux density of the persistent radio source varies by around ten per cent on day timescales, and very long baseline radio interferometry yields an angular size of less than 1.7 milliarcseconds. Our observations are inconsistent with the fast radio burst having a Galactic origin or its source being located within a prominent star-forming galaxy. Instead, the source appears to be co-located with a low-luminosity active galactic nucleus or a previously unknown type of extragalactic source. Localization and identification of a host or counterpart has been essential to understanding the origins and physics of other kinds of transient events, including gamma-ray bursts and tidal disruption events. However, if other fast radio bursts have similarly faint radio and optical counterparts, our findings imply that direct subarcsecond localizations may be the only way to provide reliable associations.

Hypernatremic Dehydration in Breast Fed Infants: Lessons from a Baby-Friendly Hospital.

AIM: To determine the incidence, presentation and outcome of all neonates admitted to the University Hospital of the West Indies with a diagnosis of breastfeeding associated hypernatremic dehydration during a 15-year period and make comparisons with an earlier study done at the institution. METHODS: A retrospective review of the files of neonates admitted to the neonatal unit with breastfeeding associated hypernatremic dehydration between January 2002 and December 2016 was conducted. Data on maternal and neonatal demographics, presentation, laboratory results and outcome were extracted and descriptive analyses performed. Statistical significance was taken at the level p < 0.05. RESULTS: Eighty neonates were entered into the study, 79 were inborn giving an incidence of 2.5 per 1000 live births. Fifty-five (71%) mothers were primiparous, with a mean ± SD age of 29.5 ± 5.6 years and mean ± SD length of hospital stay 2.6 ± 1.5 days. Fifty-six (71%) neonates were exclusively breastfed with a mean ± SD age at presentation of 5.6 ± 3.8 days, mean ± SD percentage weight loss of 16.3% ± 6.1% and a mean serum ± SD sodium of 156.1 ± 8.3 mmol/l. Fifty-four (68%) neonates were admitted from home and 22 (28%) from the postnatal ward. Complications seen included acute kidney injury 6 (8%), seizures 2 (3%), hypotonia 1 (1%) and bradycardia 1 (1%). The neonates were detected earlier, presented with a significantly lower mean serum sodium, urea and creatinine (p < 0.05), had less severe complications and no deaths compared with neonates in the previous study. CONCLUSION: Early intervention can make a positive impact on the severity and complications of breastfeeding associated hypernatremia.

Imaging features and diagnosis of tuberculosis of the breast.

AIM: To outline the pathophysiology, clinical presentation, imaging features, and relevant investigations of the different subtypes of breast tuberculosis (TB). MATERIALS AND METHODS: A review was undertaken of all cases (33 in total) of breast TB presenting to Barts Health NHS Trust within a 10-year period, including patient demographics, imaging features, and route of diagnosis. RESULTS: Thirty-three cases of proven granulomatous TB of the breast were identified (11 mastitis obliterans, 10 nodular caseous form, five sclerosing form, four disseminated disease, and three abnormal axillary lymph nodes). No cases of miliary breast TB were identified. Fine-needle aspiration cytology aided diagnosis in six patients (<20% of cases); however, the majority of patients required further investigation; namely core biopsy. Over a third of patients (12/33) had multiple clinic attendances prior to diagnosis. Mean delay in diagnosis was 3.7 months (median 0 months, IQR= 3). CONCLUSION: Breast TB is a rare challenging diagnosis with a wide range of imaging features. Core biopsy is essential for definitive diagnosis. A multidisciplinary approach involving surgeons, radiologists, TB consultants, and microbiologists is required, coupled with a high index of clinical suspicion in order to aid timely diagnosis, and initiate prompt treatment to reduce complications.

International comparisons of preterm birth: higher rates of late preterm birth are associated with lower rates of stillbirth and neonatal death.

OBJECTIVE: To examine international rates of preterm birth and potential associations with stillbirths and neonatal deaths at late preterm and term gestation. DESIGN: Ecological study. SETTING: Canada, USA and 26 countries in Europe. POPULATION: All deliveries in 2004. METHODS: Information on preterm birth (<37, 32-36, 28-31 and 24-27 weeks of gestation) and perinatal deaths was obtained for 28 countries. Data sources included files and publications from Statistics Canada, the EURO-PERISTAT project and the National Center for Health Statistics. Pearson correlation coefficients and random-intercept Poisson regression were used to examine the association between preterm birth rates and gestational age-specific stillbirth and neonatal death rates. Rate ratios with 95% confidence intervals were estimated after adjustment for maternal age, parity and multiple births. MAIN OUTCOME MEASURES: Stillbirths and neonatal deaths ≥ 32 and ≥ 37 weeks of gestation. RESULTS: International rates of preterm birth (<37 weeks) ranged between 5.3 and 11.4 per 100 live births. Preterm birth rates at 32-36 weeks were inversely associated with stillbirths at ≥ 32 weeks (adjusted rate ratio 0.94, 95% CI 0.92-0.96) and ≥ 37 weeks (adjusted rate ratio 0.88, 95% CI 0.85-0.91) of gestation and inversely associated with neonatal deaths at ≥ 32 weeks (adjusted rate ratio 0.88, 95% CI 0.85-0.91) and ≥ 37 weeks (adjusted rate ratio 0.82, 95% CI 0.78-0.86) of gestation. CONCLUSIONS: Countries with high rates of preterm birth at 32-36 weeks of gestation have lower stillbirth and neonatal death rates at and beyond 32 weeks of gestation. Contemporary rates of preterm birth are indicators of both perinatal health and obstetric care services.

The reorganized brain: how treatment strategies for stroke and amblyopia can inform our knowledge of plasticity throughout the lifespan.

Neural plasticity plays a crucial role in human development. During development, neural networks are shaped by experience-dependent processes that selectively strengthen and prune connections so that those that remain match the environment and process it optimally. Over time, neural connections become more stable, forming widely distributed, interconnected networks involving balanced excitation and inhibition and structural stabilizers like myelin. It was long believed that the potential for organization or reorganization existed only during early development. However, the successful treatments for adults with stroke or amblyopia discussed in this issue suggest that the potential for significant reorganization persists well into adulthood. Thus, development can be thought of as the stabilization of connections to match the current environment but with considerable residual plasticity that can be revealed if there is a shift in the excitatory: inhibitory balance or the removal of the structural stabilizers.

Mechanical Thrombectomy for Treatment of Cerebral Venous Sinus Thrombosis in Vaccine-Induced Immune Thrombotic Thrombocytopenia.

Reports of a rare form of cerebral venous sinus thrombosis with profound thrombocytopenia have emerged following introduction of the adenovirus-vectored coronavirus disease 2019 (COVID-19) vaccines. Between March and June 2021, seven cases of refractory vaccine-induced immune thrombotic thrombocytopenia were referred to our institution for mechanical thrombectomy. The condition of 1 patient deteriorated during interhospital transfer, and the remaining 6 underwent successful recanalization. No procedure-related adverse events were reported. At the time of this writing, 3 patients have been discharged with a good functional outcome (mRS 0-1), one required rehabilitation for mild dysarthria and vocal cord palsy (mRS 3), and 2 have died due to severe mass effect. Our anecdotal experience suggests that endovascular therapy may be safe and effective in reducing thrombus burden in selected cases of postvaccination cerebral venous sinus thrombosis.

Virtual patients: an effective educational intervention to improve paediatric basic specialist trainee education in the management of suspected child abuse?

Child abuse is a particularly difficult subject to teach at both undergraduate and postgraduate level. Most doctors are dissatisfied with their training in child abuse recognition and management. We developed an interactive video based Virtual Patient to provide formal training for paediatric Basic Specialist Trainees in the recognition of suspected child abuse. The Virtual Patient case revolves around the management of suspected physical abuse in a seven month old child, who initially presents to the Emergency Department with viral upper respiratory tract symptoms. This Virtual Patient was used to facilitate a case discussion with Basic Specialist Trainees. A questionnaire was developed to determine their perception of the value of the Virtual Patient as an educational tool. Twenty five Basic Specialist Trainees completed the questionnaire. Upon completion of the case, 23/25 (92%) participants reported greater self confidence in their ability to recognize cases of suspected child abuse and 24/25 (96%) of participants reported greater self confidence in their ability to report cases of suspected child abuse. Basic Specialist Trainees perceived the Virtual Patient to be a useful educational tool. Virtual Patients may have a role to play in enhancing postgraduate training in the recognition of suspected child abuse.

Haemorrhagic shock from solid tumours of the adrenal gland: a case of bleeding primary adrenal lymphoma.

Suprarenal or adrenal gland haemorrhage is an uncommon but potentially lethal condition if unrecognised. Adrenal masses rarely present with haemorrhage, but they remain an important differential aetiology for adrenal bleeding. We present a novel case of primary adrenal lymphoma with adrenal haemorrhage in a middle-aged woman who presented with right-sided abdominal pain and class 1 haemorrhagic shock. She was found to have spontaneous unilateral adrenal gland haemorrhage in the absence of any underlying previous pathology. Presenting features, diagnosis and subsequent oncological management are reported.

A Primary Care Randomized Controlled Trial of Hall and Conventional Restorative Techniques.

OBJECTIVES: To investigate treatment outcomes of different restorative techniques undertaken by dental therapists for primary molar carious lesions in a sample of children in New Zealand primary care. METHODS: This was a randomized controlled trial with children aged 3 to 8 y in New Zealand's Whanganui region. Children meeting inclusion criteria were randomly allocated to treatment with either the Hall technique (HT), in which a stainless-steel crown (SSC) is placed without any carious tissue removal or tooth preparation, or a non-Hall conventional restorative approach (NHT), including tooth preparation with selective carious tissue removal; this included SSC, amalgam, composite, or glass ionomer cement (GIC) restorations. Restorative outcomes after 12 and 24 mo were categorized as success, minor failure, or major failure. RESULTS: Of the 295 eligible children, 149 and 146 were allocated to the HT and NHT groups, respectively, with a total of 570 carious primary molars treated by 13 dental therapists. The participant follow-up rates at 12 and 24 mo were 95% and 91%. SSCs were the most commonly used restoration in the NHT group (60%), followed by GIC (28%). SSCs were the most successful restorations regardless of whether they were placed with the HT or NHT, with success rates of 89% and 92% at 12 mo and 85% and 86% at 24 mo. In the NHT group, the treatment material was a predictor of minor failure at 12 and 24 mo, with significantly more failures with GICs. CONCLUSIONS: SSCs placed by dental therapists are a highly successful restoration for the primary dentition, regardless of whether they are placed with the HT or conventionally. The high failure rate of glass ionomer restorations means that they cannot be recommended for widespread use in New Zealand primary care (Australian New Zealand Clinical Trials Registry, ACTRN12614000844640). KNOWLEDGE TRANSFER STATEMENT: The findings of this study can be used by policy makers and clinicians when deciding on which materials and which approach to use to maximize success and to minimize retreatment rates when providing restorative treatment for carious primary molars in children's primary oral health care. Results also suggest that undertaking research in the primary care setting may enhance translation of new knowledge and techniques into clinicians' hands.

Timing of delivery for pregnancies with congenital diaphragmatic hernia.

A recent report has suggested that delivery at early term ages may be associated with lower mortality among infants with congenital diaphragmatic hernia. We sought to confirm this finding by examining gestational age-specific mortality in the USA in term infants with isolated congenital diaphragmatic hernia, delivered following the spontaneous onset of labour. In the final population of 928 infants, neonatal and infant mortality decreased with advancing gestation, from 25 and 36% at 37 weeks of gestation, respectively, to 17 and 20% at 40 weeks of gestation, respectively. Log-binomial regression models showed that neonatal and infant mortality at 37 weeks of gestation were significantly higher than at 40 weeks. Further evidence, ideally from a randomised trial, is needed before recommendations for clinical practice on timing of delivery should be made.

Mercury radar imaging: evidence for polar ice.

The first unambiguous full-disk radar mapping of Mercury at 3.5-centimeter wavelength, with the Goldstone 70-meter antenna transmitting and 26 antennas of the Very Large Array receiving, has provided evidence for the presence of polar ice. The radar experiments, conducted on 8 and 23 August 1991, were designed to image the half of Mercury not photographed by Mariner 10. The orbital geometry allowed viewing beyond the north pole of Mercury; a highly reflective region was clearly visible on the north pole during both experiments. This polar region has areas in which the circular polarization ratio (pt) was 1.0 to 1.4; values < approximately 0.1 are typical for terrestrial planets. Such high values of have hitherto been observed in radar observations only from icy regions of Mars and icy outer planet satellites.

Radar images of Mars.

Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density. The transmitter system was the 70-m antenna of the Deep Space Network at Goldstone, California. The surface of Mars was illuminated with continuous wave radiation at a wavelength of 3,5 cm. The reflected energy was mapped in individual 12-minute snapshots with the VLA in its largest configuration; fringe spacings as small as 67 km were obtained. The images reveal near-surface features including a region in the Tharsis volcano area, over 2000 km in east-west extent, that displayed no echo to the very low level of the radar system noise. The feature, called Stealth, is interpreted as a deposit of dust or ash with a density less than about 0.5 gram per cubic centimeter and free of rocks larger than 1 cm across. The deposit must be several meters thick and may be much deeper. The strongest reflecting geological feature was the south polar ice cap, which was reduced in size to the residual south polar ice cap at the season of observation. The cap image is interpreted as arising from nearly pure CO(2) or H(2)O ice with a small amount of martian dust (less than 2 percent by volume) and a depth greater than 2 to 5 m. Only one anomalous reflecting feature was identified outside of the Tharsis region, although the Elysium region was poorly sampled in this experiment and the north pole was not visible from Earth.

Radar reflectivity of titan.

The present understanding of the atmosphere and surface conditions on Saturn's largest moon, Titan, including the stability of methane, and an application of thermodynamics leads to a strong prediction of liquid hydrocarbons in an ethane-methane mixture on the surface. Such a surface would have nearly unique microwave reflection properties due to the low dielectric constant. Attempts were made to obtain reflections at a wavelength of 3.5 centimeters by means of a 70-meter antenna in California as the transmitter and the Very Large Array in New Mexico as the receiving instrument. Statistically significant echoes were obtained that show Titan is not covered with a deep, global ocean of ethane, as previously thought. The experiment yielded radar cross sections normalized by the Titan disk of 0.38 +/- 0.15, 0.78 +/- 0.15, and 0.25 +/- 0.15 on three consecutive nights during which the sub-Earth longitude on Titan moved 50 degrees. The result for the combined data for the entire experiment is 0.35 +/- 0.08. The cross sections are very high, most consistent with those of the Galilean satellites; no evidence of the putative liquid ethane was seen in the reflection data. A global ocean as shallow as about 200 meters would have exhibited reflectivities smaller by an order of magnitude, and below the detection limit of the experiment. The measured emissivity at similar wavelengths of about 0.9 is somewhat inconsistent with the high reflectivity.

Role of surface-active phospholipids in gastric cytoprotection.

Intragastric administration of a liposomal surfactant suspension markedly reduced acid-induced gastric ulcerogenesis and bleeding in rats. The concentration of surface-active molecules intrinsically present in the gastric mucosa was increased two to six times by administration of 16,16-dimethyl prostaglandin E2. Thus, local accumulation of surface-active phospholipids may be an integral component of the cytoprotective mechanism activated by prostaglandin treatment.

A nonpeptidyl growth hormone secretagogue.

A nonpeptidyl secretagogue for growth hormone of the structure 3-amino-3-methyl-N-(2,3,4,5-tetrahydro-2-oxo-1-([2'-(1H-tetrazol-5 -yl) (1,1'-biphenyl)-4-yl]methyl)-1H-1-benzazepin-3(R)-yl)-butanamid e (L-692,429) has been identified. L-692,429 synergizes with the natural growth hormone secretagogue growth hormone-releasing hormone and acts through an alternative signal transduction pathway. The mechanism of action of L-692,429 and studies with peptidyl and nonpeptidyl antagonists suggest that this molecule is a mimic of the growth hormone-releasing hexapeptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6). L-692,429 is an example of a nonpeptidyl specific secretagogue for growth hormone.

Natural attenuation of a plume from an emplaced coal tar creosote source over 14 years.

An emplaced source of coal tar creosote within the sandy Borden research aquifer has documented the long-term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals have been extensively sampled seven times using a monitoring network of approximately 280, 14-point multilevel samplers. A model of source dissolution using Raoult's Law adequately predicted the dissolution of 9 of 11 compounds. Mass transformation has limited the extent of the plumes as groundwater has flowed more than 500 m, yet the plumes are no longer than 50 m. Phenol and xylenes have been removed and naphthalene has attenuated from its maximum extent on day 1357. Some compound plumes have reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass lost is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor, yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. The complex evolution of these plumes has been well documented but understanding the controlling biotransformation processes is still elusive. This study has shown that anticipating bioattenuation patterns should only be considered at the broadest scale. Generally, the greatest mass loss is associated with those compounds that have a high solubility and low partitioning coefficients.

Congenital Hypothalamic "Hamartoblastoma" Versus "Hamartoma": Suggestions for Neuropathologic Terminology Emanating From a Mid-gestational Autopsy Case of Pallister-Hall Syndrome.

Pallister-Hall syndrome (PHS) is a rare malformative disorder that is due to truncating functional repressor mutations in GLI3. Since the seminal publication in 1980, hypothalamic tumors have been recognized to be a cardinal feature of PHS. In their original description of the neuropathologic features of PHS, Clarren et al. coined the term "hamartoblastoma" to characterize what they deemed to be a dual malformative and neoplastic mass of the hypothalamus. In subsequent published cases/series of PHS, the term "hamartoma" was often substituted for hamartoblastoma given what appeared to be a benign natural history of this lesion. Additional confusion in the literature has ensued since most hypothalamic hamartomas (HH) encountered on the clinical neuropathology service are "isolated" in nature (ie, no other congenital malformations) and present in a very different and stereotypical fashion with gelastic seizures and/or precocious puberty. While genomic investigations of isolated HH have begun to uncover a mutational profile of these cases, GLI3 mutations have only been recognized in a small subset of isolated HH. Herein, we describe the autopsy findings from a 21-week gestational age fetus with features of PHS. Moreover, we provide a detailed description of the hypothalamic tumor affecting this fetus and propose a novel subclassification of HH, distinguishing syndromic from isolated forms based upon the presence or absence of neocortical-like areas.

Heat shock-mediated cell cycle blockage and G1 cyclin expression in the yeast Saccharomyces cerevisiae.

For cells of the yeast Saccharomyces cerevisiae, heat shock causes a transient inhibition of the cell cycle-regulatory step START. We have determined that this heat-induced START inhibition is accompanied by decreased CLN1 and CLN2 transcript abundance and by possible posttranscriptional changes to CLN3 (WHI1/DAF1) cyclin activity. Persistent CLN2 expression from a heterologous promoter or the CLN2-1 or CLN3-1 alleles that are thought to encode cyclin proteins with increased stability eliminated heat-induced START inhibition but did not affect other aspects of the heat shock response. Heat-induced START inhibition was shown to be independent of functions that regulate cyclin activity under other conditions and of transcriptional regulation of SWI4, an activator of cyclin transcription. Cells lacking Bcy1 function and thus without cyclic AMP control of A kinase activity were inhibited for START by heat shock as long as A kinase activity was attenuated by mutation. We suggest that heat shock mediates START blockage through effects on the G1 cyclins.

Supporting the emergence of dental informatics with an online community.

Dental Informatics (DI) is the application of computer and information science to improve dental practice, research, education, and program administration. As an emerging field, dental informatics faces many challenges and barriers to establishing itself as a full-fledged discipline; these include the small number of geographically dispersed DI researchers as well as the lack of DI professional societies and DI-specific journals. E-communities have the potential to overcome these obstacles by bringing researchers together at a resources hub and giving them the ability to share information, discuss topics, and find collaborators. In this paper, we discuss our assessment of the information needs of individuals interested in DI and discuss their expectations for an e-community so that we can design an optimal electronic infrastructure for the Dental Informatics Online Community (DIOC). The 256 survey respondents indicated they prefer electronic resources over traditional print material to satisfy their information needs. The most frequently expected benefits from participation in the DIOC were general information (85% of respondents), peer networking (31.1%), and identification of potential collaborators and/or research opportunities (23.2%). We are currently building the DIOC electronic infrastructure: a searchable publication archive and the learning center have been created, and the people directory is underway. Readers are encouraged to access the DIOC Website at www.dentalinformatics.com and initiate a discussion with the authors of this paper.