Explore the vast range of titles available.

Bacteria and their phages continually coevolve in a molecular arms race. For example, phages use anti-CRISPR proteins to inhibit the bacterial type I and II CRISPR systems (see the Perspective by Koonin and Makarova). Watters et al. and Marino et al. used bioinformatic and experimental approaches to identify inhibitors of type V CRISPR-Cas12a. Cas12a has been successfully engineered for gene editing and nucleic acid detection. Some of the anti-Cas12a proteins identified in these studies had broad-spectrum inhibitory effects on Cas12a orthologs and could block Cas12a-mediated genome editing in human cells. Science , this issue p. 236 , p. 240 ; see also p. 156 CRISPR-Cas12a inhibitors that block gene editing in human cells are identified. Bacterial CRISPR-Cas systems protect their host from bacteriophages and other mobile genetic elements. Mobile elements, in turn, encode various anti-CRISPR (Acr) proteins to inhibit the immune function of CRISPR-Cas. To date, Acr proteins have been discovered for type I (subtypes I-D, I-E, and I-F) and type II (II-A and II-C) but not other CRISPR systems. Here, we report the discovery of 12 acr genes, including inhibitors of type V-A and I-C CRISPR systems. AcrVA1 inhibits a broad spectrum of Cas12a (Cpf1) orthologs—including MbCas12a, Mb3Cas12a, AsCas12a, and LbCas12a—when assayed in human cells. The acr genes reported here provide useful biotechnological tools and mark the discovery of acr loci in many bacteria and phages.

Spatial structure in biology, spanning molecular, organellular, cellular, tissue, and organismal scales, is encoded through a combination of genetic and epigenetic factors in individual cells. Microscopy remains the most direct approach to exploring the intricate spatial complexity defining biological systems and the structured dynamic responses of these systems to perturbations. Genetic screens with deep single‐cell profiling via image features or gene expression programs have the capacity to show how biological systems work in detail by cataloging many cellular phenotypes with one experimental assay. Microscopy‐based cellular profiling provides information complementary to next‐generation sequencing (NGS) profiling and has only recently become compatible with large‐scale genetic screens. Optical screening now offers the scale needed for systematic characterization and is poised for further scale‐up. We discuss how these methodologies, together with emerging technologies for genetic perturbation and microscopy‐based multiplexed molecular phenotyping, are powering new approaches to reveal genotype–phenotype relationships. Graphical Abstract This review discusses the technological advances that enable studies of genotype‐to‐phenotype relationships with microscopy‐based imaging and proposes a roadmap for the future development and application of pooled profiling screens with image‐based phenotypes.

Wrist-worn sleep actigraphs are limited for evaluating sleep, especially in sleepers who lie awake in bed without moving for extended periods. Sleep logs depend on the accuracy of perceiving and remembering times of being awake. Here we evaluated pressing an event-marker button while lying awake under two conditions: self-initiated pressing every 5 to 10 minutes or pressing when signaled every 5 minutes by a vibration pulse from a wristband. We evaluated the two conditions for acceptability and their concordance with actigraphically scored sleep. Twenty-nine adults wore actigraphs on six nights. On nights 1 and 4, they pressed the marker to a vibration signal, and on nights 2 and 5, they self-initiated presses without any signal. On nights 3 and 6, they were told not to press the marker. Every morning they filled out a sleep log about how they had slept. The vibration band was unacceptable to 42% of the participants, who judged it too disturbing to their sleep. Self-initiated pressing was acceptable to all, although it reduced log reported sleep depth compared to a no pressing condition. Estimations of sleep onset latency were considerably longer by button pressing than by actigraphy. Agreement of epoch-by-epoch sleep scoring by actigraphy and by button pressing was poor (kappa = 0.23) for self-initiated pressing and moderate (kappa = 0.46) for pressing in response to a vibration. Self-initiated button pressing to indicate being awake while lying in bed is acceptable to many, interferes little with sleep, and adds substantially to the information given by actigraphy.

The dopamine D2 receptor has been extensively studied in relation to alcoholism, substance abuse, and nicotine dependence. The most frequently examined polymorphism linked to this gene is the Taq1A restriction fragment length polymorphism (RFLP) (dbSNP rs1800497; g.32806C>T in GenBank AF050737.1), which has been associated with a reduction in D2 receptor density, although this is not universally accepted. The Taq1A RFLP lies 10 kB downstream of DRD2 and may therefore fall within a different coding region than the DRD2 gene or within a regulatory region. Within this downstream region, we have identified a novel kinase gene, named ankyrin repeat and kinase domain containing 1 (ANKK1), which contains a single serine/threonine kinase domain and is expressed at low levels in placenta and whole spinal cord RNA. This gene is a member of an extensive family of proteins involved in signal transduction pathways. The DRD2 Taq1A RFLP is a single nucleotide polymorphism (SNP) that causes an amino acid substitution within the 11th ankyrin repeat of ANKK1 (p.Glu713Lys), which, while unlikely to affect structural integrity, may affect substrate‐binding specificity. If this is the case, then changes in ANKK1 activity may provide an alternative explanation for previously described associations between the DRD2 Taq1A RFLP and neuropsychiatric disorders such as addiction. Hum Mutat 23:540‐545, 2004. © 2004 Wiley‐Liss, Inc.

Double-β-decay involves the simultaneous conversion of two neutrons into two protons, and the emission of two electrons and two neutrinos; the neutrinoless process, although not yet observed, is thought to involve the emission of the two electrons but no neutrinos. The search for neutrinoless-double-β-decay probes fundamental properties of neutrinos, including whether or not the neutrino and antineutrino are distinct particles. Double-β-decay detectors are large and expensive, so it is essential to achieve the highest possible sensitivity with each study, and removing spurious contributions (‘background’) from detected signals is crucial. In the nEXO neutrinoless-double-β-decay experiment, the identification, or ‘tagging’, of the 136 Ba daughter atom resulting from the double-β decay of 136 Xe provides a technique for discriminating background. The tagging scheme studied here uses a cryogenic probe to trap the barium atom in a solid xenon matrix, where the barium atom is tagged through fluorescence imaging. Here we demonstrate the imaging and counting of individual barium atoms in solid xenon by scanning a focused laser across a solid xenon matrix deposited on a sapphire window. When the laser irradiates an individual atom, the fluorescence persists for about 30 seconds before dropping abruptly to the background level—a clear confirmation of one-atom imaging. Following evaporation of a barium deposit, the residual barium fluorescence is 0.16 per cent or less. Our technique achieves the imaging of single atoms in a solid noble element, establishing the basic principle of barium tagging for nEXO. Single barium atoms trapped in a solid xenon matrix can be imaged and counted by scanning with a focused laser, providing a possible tagging technique for the neutrinoless-double-β-decay experiment nEXO.

We review a technique for solving a class of classical linear partial diferential systems of relevance to physics in Minkowski spacetime. All the equations are amenable to analysis in terms of complex solutions in the kernel of the scalar Laplacian and a complexifed Hertz potential. The complexifcation prescription ensures the existence of regular physical solutions with chirality and propagating, non-singular, pulse-like characteristics that are bounded in all three spatial dimensions. The technique is applied to the source-free Maxwell, Bopp-Landé-Podolsky and linearised Einstein feld systems, and particular solutions are used for constructing classical models describing single-cycle laser pulses and a mechanism is discussed for initiating astrophysical jets. Our article concludes with a brief introduction to spacetime Cliford algebra ideals that we use to represent spinor felds. We employ these to demonstrate how the same technique used for tensor felds enables one to construct new propagating, chiral, non-singular, pulse-like spinor solutions to the massless Dirac equation in Minkowski spacetime.

Zebrafish have great potential to contribute to our understanding of behavioral genetics and thus to contribute to our understanding of the etiology of psychiatric disease. However, progress is dependent upon the rate at which behavioral assays addressing complex behavioral phenotypes are designed, reported and validated. Here we critically review existing behavioral assays with particular focus on the use of adult zebrafish to explore executive processes and phenotypes associated with human psychiatric disease. We outline the case for using zebrafish as models to study impulse control and attention, discussing the validity of applying extant rodent assays to zebrafish and evidence for the conservation of relevant neural circuits.

AbstractRegionalization has become a buzzword in US health care policy. Regionalization, however, has varied meanings, and definitions have lacked contextual information important to understanding its role in improving care. This concept review is a comprehensive primer and summation of 8 common core components of the national models of regionalization informed by text‐based analysis of the writing of involved organizations (professional, regulatory, and research) guided by semistructured interviews with organizational leaders. Further, this generalized model of regionalized care is applied to sepsis care, a novel discussion, drawing on existing small‐scale applications. This discussion highlights the fit of regionalization principles to the sepsis care model and the actualized and perceived potential benefits. The principal aim of this concept review is to outline regionalization in the United States and provide a roadmap and novel discussion of regionalized care integration for sepsis care.

We report the case of a five-month-old girl presenting with a subluxed left hip following normal neonatal clinical examination and serial ultrasound screening. Her only risk factor for developmental dysplasia of the hip (DDH) was breech presentation. She underwent closed reduction with successful concentric reduction. This case demonstrates that hip subluxation can occur after normal ultrasound screening, and has important clinical and medicolegal implications. Consideration should be given to further follow-up in children with overt risk factors for DDH, even after normal ultrasound examination.

BackgroundGiant cell arteritis is the most common vasculitis in the western world in the over 50 population. The morbidity associated with its natural progression and treatment is significant. No single investigation has been identified to accurately confirm or reject its diagnosis, though for some years biopsy of the superficial temporal artery has been carried out to support the diagnostic process. More recently, doppler ultrasound of the artery has gained prominence, though its widespread use is limited.Temporal artery biopsy (TAB) is a significant use of resources, involving a surgeon and their team, as well as a histopathologist. It is an invasive procedure with the risks that this entails. It behoves the referring doctor to ensure that the probability of a positive result is as high as practicable.ObjectivesTo determine the factors providing the highest likelihood of a positive TAB result.MethodsThe notes of all patients undergoing a TAB during a 3 year period 2013–2016 were requested from the Medical Records department at a district general hospital. The first 100 of these were reviewed by the authors. Each set of notes was examined for the following:- Demographics (sex, age)- The first department the patient was referred to (Rheumatology/Ophthalmology/Neurology/direct from the General Practitioner to Vascular Surgery)- Period of time from symptom onset to biopsy- Period of time on steroids to biopsy- Initial dose of steroids prescribed- Pre-treatment ESR- Pre-treatment CRP- Presence of symptoms (headache/jaw claudication/polymyalgia rheumatica)- Other causes for a raised ESR- The pre-test probability of a positive TAB result as assessed by the reviewer- TAB result as reported by local histopathologist- Evidence of the biopsy result impacting treatmentResultsOf the 100 TAB’s reviewed, 16 yielded positive results (16%). A breakdown of the notes review for these patients is included in the following table:Abstract AB0684 – Table 1Positive TAB16/100Visual symptoms6/16 Age (years)58–88, Mean 73Jaw claudication5/16Female:Male13:3Headache11/16GP referral direct to Vascular Surgery5/16PMR1/16Initial referral to Rheumatology4/16Other causes of raised ESR3/16Initial referral to Ophthalmology4/16Pre-test probability of positive result9/16Initial referral to Neurology3/16 Biopsy influencing treatment 6/7Symptom onset to TAB (days)14–90, Mean 52Steroid duration before TAB1–28 daysSteroid starting dose range30–500 mgConclusionsThis study has shown that less than a fifth of TAB’s conducted during this period at our district general hospital yielded a positive result. There is scope to improve this yield significantly if we identify candidates for TAB better.There was no positive result for any of the 16 patients less than 58 years of age. The majority had a raised CRP and ESR, though one patient had a CRP of 2. This reflects the need for vigilance before discounting GCA as a diagnosis.One patient had a positive TAB even after 28 days of prednisolone 40 mg daily. The majority (14/16) had their biopsy within 3 weeks of steroid initiation, indicating that a short delay in biopsy does not rule out a positive result.This study will help us develop a local pathway including Ophthalmology, Neurology, Vascular Surgery and Primary Care to improve the yield of positive TAB. This will improve patient experience as well as ensure appropriate use of resources.Disclosure of InterestNone declared