Isolation and sequence of omcA, a gene encoding a decaheme outer membrane cytochrome c of Shewanella putrefaciens MR-1, and detection of omcA homologs in other strains of S. putrefaciens

AbstractThe sequence of the omcA gene, which encodes a decaheme cytochrome c that is localized to the outer membrane (OM) of Shewanella putrefaciens MR-1, was determined. The 2202 bp nucleotide sequence of omcA encodes for 734 amino acids with a predicted molecular protein mass of 78.6 kDa. Comparison with the amino-terminal sequence of the mature protein suggests the presence of a hydrophobic leader sequence which is cleaved during translocation of the protein to the OM. This leader sequence has a lipoprotein consensus sequence for signal peptidase II at the cleavage site. The predicted mature protein is comprised of 708 amino acids with a predicted molecular mass of 75.8 kDa, but the addition of ten covalently attached heme c groups and covalent lipid modification to the amino-terminal cysteine increases the predicted mass to 82.7 kDa. This is consistent with its apparent mass of 83 kDa in SDS-PAGE gels. The predicted amino acid sequence for the OmcA protein shows no significant homology to known proteins. A RNA of approx. 2300 bases that hybridizes to the omcA gene was detected in anaerobically grown MR-1 cells. The size of this transcript is similar to the coding region of the omcA gene, suggesting that it is not part of a multicistronic operon. Similar to MR-1, four other strains of S. putrefaciens were all found to localize a majority of their membrane-bound cytochromes to the OM when grown under anaerobic conditions, and all contained an OM cytochrome of similar size to OmcA. In two of these strains, MR-4 and MR-8, a homolog of omcA was identified by RT-PCR and Southern blotting using primers and probes specific for omcA of MR-1. Western blot analysis using a polyclonal antibody to OmcA was similarly positive in strains MR-4 and MR-8. Partial nucleotide sequence analysis of these homologs demonstrated 74–77% predicted amino acid homology with OmcA of MR-1. In contrast, strains MR-30 and MR-42 tested negative for omcA homologs by Southern and Northern blots, RT-PCR, and Western blots

The Initial Configuration of Young Stellar Clusters: A K-band Number Counts Analysis of the Surface Density of Stars

We present an analysis of K-band stellar distributions for the young stellar clusters GGD 12-15, IRAS 20050+2720, and NGC 7129. We find that the two deeply embedded clusters, GGD 12-15 and IRAS 20050+2720, are not azimuthally symmetric and show a high degree of structure which traces filamentary structure observed in 850 micron emission maps. In contrast, the NGC 7129 cluster is circularly symmetric, less dense, and anti-correlated to 850 micron emission, suggesting recent gas expulsion and dynamical expansion have occured. We estimate stellar volume densities from nearest neighbor distances, and discuss the impact of these densities on the evolution of circumstellar disks and protostellar envelopes in these regions.Comment: 44 pages, 26 figures, Accepted to ApJ. Changes include extinction mapping, Monte Carlo field star modeling, and Nyquist sampled azimuthal stellar distributions. A version with full resolution figures is available at http://astro.pas.rochester.edu/~rguter/preprints/gutermuth_sd.tar.g

Integrative Single-Cell RNA-Seq and ATAC-Seq Analysis of Human Developmental Hematopoiesis.

Regulation of hematopoiesis during human development remains poorly defined. Here we applied single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) to over 8,000 human immunophenotypic blood cells from fetal liver and bone marrow. We inferred their differentiation trajectory and identified three highly proliferative oligopotent progenitor populations downstream of hematopoietic stem cells (HSCs)/multipotent progenitors (MPPs). Along this trajectory, we observed opposing patterns of chromatin accessibility and differentiation that coincided with dynamic changes in the activity of distinct lineage-specific transcription factors. Integrative analysis of chromatin accessibility and gene expression revealed extensive epigenetic but not transcriptional priming of HSCs/MPPs prior to their lineage commitment. Finally, we refined and functionally validated the sorting strategy for the HSCs/MPPs and achieved around 90% enrichment. Our study provides a useful framework for future investigation of human developmental hematopoiesis in the context of blood pathologies and regenerative medicine.The study was supported by European Research Council project 677501 – ZF_Blood (to A.C. and A.M.R), EMBO small grant (to A.C.) and a core support grant from the Wellcome Trust and MRC to the Wellcome Trust – Medical Research Council Cambridge Stem Cell Institute

Aseptic Meningitis Epidemic during a West Nile Virus Avian Epizootic

While enteroviruses have been the most commonly identified cause of aseptic meningitis in the United States, the role of the emerging, neurotropic West Nile virus (WNV) is not clear. In summer 2001, an aseptic meningitis epidemic occurring in an area of a WNV epizootic in Baltimore, Maryland, was investigated to determine the relative contributions of WNV and enteroviruses. A total of 113 aseptic meningitis cases with onsets from June 1 to September 30, 2001, were identified at six hospitals. WNV immunoglobulin M tests were negative for 69 patients with available specimens; however, 43 (61%) of 70 patients tested enterovirus-positive by viral culture or polymerase chain reaction. Most (76%) of the serotyped enteroviruses were echoviruses 13 and 18. Enteroviruses, including previously rarely detected echoviruses, likely caused most aseptic meningitis cases in this epidemic. No WNV meningitis cases were identified. Even in areas of WNV epizootics, enteroviruses continue to be important causative agents of aseptic meningitis

"Now he walks and walks, as if he didn't have a home where he could eat": food, healing, and hunger in Quechua narratives of madness

In the Quechua-speaking peasant communities of southern Peru, mental disorder is understood less as individualized pathology and more as a disturbance in family and social relationships. For many Andeans, food and feeding are ontologically fundamental to such relationships. This paper uses data from interviews and participant observation in a rural province of Cuzco to explore the significance of food and hunger in local discussions of madness. Carers’ narratives, explanatory models, and theories of healing all draw heavily from idioms of food sharing and consumption in making sense of affliction, and these concepts structure understandings of madness that differ significantly from those assumed by formal mental health services. Greater awareness of the salience of these themes could strengthen the input of psychiatric and psychological care with this population and enhance knowledge of the alternative treatments that they use. Moreover, this case provides lessons for the global mental health movement on the importance of openness to the ways in which indigenous cultures may construct health, madness, and sociality. Such local meanings should be considered by mental health workers delivering services in order to provide care that can adjust to the alternative ontologies of sufferers and carers

Outside in-group and out-group identities? Constructing male solidarity and female exclusion in UK builders’ talk

This article examines the spoken interactions of a group of British construction workers to discover whether it is possible to identify a distinctive ‘builders’ discourse’. Given that builders work for a mostly all-male profession (Curjao, 2006), we ask whether the ways in which male builders converse with each other while ‘on the job’ can be held in any way responsible for the under-representation of women within this major occupational sector in the UK. This article reports on a case study of the conversations of three white, working-class, male builders, which took place while travelling in a truck between different building sites. This forms part of a larger ethnographic study of builders’ discourse in different work locations. The analysis shows that male builders are highly collaborative in constructing narratives of in-group and out-group identities (Duszak, 2002; Tajfel, 1978). Various other male groups are demonized in these conversations: Polish immigrant builders, rude clients and rival builders. However, there is almost no reference to women. The article concludes that women are viewed as so unthreatening to male ascendancy in the building industry that they do not even feature within the ‘out-group’

Short-Course Therapy for Urinary Tract Infections in Children: The SCOUT Randomized Clinical Trial

IMPORTANCE: There is a paucity of pediatric-specific comparative data to guide duration of therapy recommendations in children with urinary tract infection (UTI). OBJECTIVE: To compare the efficacy of standard-course and short-course therapy for children with UTI. DESIGN, SETTING, PARTICIPANTS: The Short Course Therapy for Urinary Tract Infections (SCOUT) randomized clinical noninferiority trial took place at outpatient clinics and emergency departments at 2 children\u27s hospitals from May 2012, through, August 2019. Data were analyzed from January 2020, through, February 2023. Participants included children aged 2 months to 10 years with UTI exhibiting clinical improvement after 5 days of antimicrobials. INTERVENTION: Another 5 days of antimicrobials (standard-course therapy) or 5 days of placebo (short-course therapy). MAIN OUTCOME MEASURES: The primary outcome, treatment failure, was defined as symptomatic UTI at or before the first follow-up visit (day 11 to 14). Secondary outcomes included UTI after the first follow-up visit, asymptomatic bacteriuria, positive urine culture, and gastrointestinal colonization with resistant organisms. RESULTS: Analysis for the primary outcome included 664 randomized children (639 female [96%]; median age, 4 years). Among children evaluable for the primary outcome, 2 of 328 assigned to standard-course (0.6%) and 14 of 336 assigned to short-course (4.2%) had a treatment failure (absolute difference of 3.6% with upper bound 95% CI of 5.5.%). Children receiving short-course therapy were more likely to have asymptomatic bacteriuria or a positive urine culture at or by the first follow-up visit. There were no differences between groups in rates of UTI after the first follow-up visit, incidence of adverse events, or incidence of gastrointestinal colonization with resistant organisms. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, children assigned to standard-course therapy had lower rates of treatment failure than children assigned to short-course therapy. However, the low failure rate of short-course therapy suggests that it could be considered as a reasonable option for children exhibiting clinical improvement after 5 days of antimicrobial treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01595529