Numerical treatment of seismic accelerograms and of inelastic seismic structural responses using harmonic wavelets

The harmonic wavelet transform is employed to analyze various kinds of nonstationary signals common in aseismic design. The effectiveness of the harmonic wavelets for capturing the temporal evolution of the frequency content of strong ground motions is demonstrated. In this regard, a detailed study of important earthquake accelerograms is undertaken and smooth joint time-frequency spectra are provided for two near-field and two far-field records; inherent in this analysis is the concept of the mean instantaneous frequency. Furthermore, as a paradigm of usefulness for aseismic structural purposes, a similar analysis is conducted for the response of a 20-story steel frame benchmark building considering one of the four accelerograms scaled by appropriate factors as the excitation to simulate undamaged and severely damaged conditions for the structure. The resulting joint time-frequency representation of the response time histories captures the influence of nonlinearity on the variation of the effective natural frequencies of a structural system during the evolution of a seismic event. In this context, the potential of the harmonic wavelet transform as a detection tool for global structural damage is explored in conjunction with the concept of monitoring the mean instantaneous frequency of records of critical structural responses

Southern hemispheric halon trends and global halon emissions, 1978–2011

The atmospheric records of four halons, H-1211 (CBrClF2), H-1301 (CBrF3), H-2402 (CBrF2CBrF2) and H-1202 (CBr2F2), measured from air collected at Cape Grim, Tasmania, between 1978 and 2011, are reported. Mixing ratios of H-1211, H-2402 and H-1202 began to decline in the early to mid-2000s, but those of H-1301 continue to increase up to mid-2011. These trends are compared to those reported by NOAA (National Oceanic and Atmospheric Administration) and AGAGE (Advanced Global Atmospheric Experiment). The observations suggest that the contribution of the halons to total tropospheric bromine at Cape Grim has begun to decline from a peak in 2008 of about 8.1 ppt. An extrapolation of halon mixing ratios to 2060, based on reported banks and predicted release factors, shows this decline becoming more rapid in the coming decades, with a contribution to total tropospheric bromine of about 3 ppt in 2060. Top-down global annual emissions of the halons were derived using a two-dimensional atmospheric model. The emissions of all four have decreased since peaking in the late 1980s–mid-1990s, but this decline has slowed recently, particularly for H-1301 and H-2402 which have shown no decrease in emissions over the past five years. The UEA (University of East Anglia) top-down model-derived emissions are compared to those reported using a top-down approach by NOAA and AGAGE and the bottom-up estimates of HTOC (Halons Technical Options Committee). The implications of an alternative set of steady-state atmospheric lifetimes are discussed. Using a lifetime of 14 yr or less for H-1211 to calculate top-down emissions estimates would lead to small, or even negative, estimated banks given reported production data. Finally emissions of H-1202, a product of over-bromination during the production process of H-1211, have continued despite reported production of H-1211 ceasing in 2010. This raises questions as to the source of these H-1202 emissions

Response to letter to editor: 'Comment on Arch et al., Trials. 2016;17:517'

In October 2015 we published the paper ‘Measurement of HbA1c in multicentre diabetes trials – should blood samples be tested locally or sent to a central laboratory: an agreement analysis’. Chatterjee and Pradhan have submitted a letter to the editor asking critical questions regarding the methods we used. We offer this letter in response

Variation in ampicillin dosing for lower respiratory tract infections and neonatal bacterial infections in US children\u27s hospitals

OBJECTIVE: We examined ampicillin dosing in pediatric patients across 3 conditions: (1) bacterial lower respiratory tract infections (LRTIs) in infants and children \u3e3 months, (2) neonates with suspected or proven sepsis, and (3) neonates with suspected central nervous system (CNS) infections. We compared our findings to dosing guidance for these specific indications. DESIGN: Retrospective cohort study. SETTING: The study included data from 32 children\u27s hospitals in the United States. METHODS: We reviewed prescriptions from the SHARPS study of antimicrobials, a survey of antibiotic prescribing from July 2016 to December 2017. Prescriptions were analyzed for indication, total daily dose per kilogram, and presence of antimicrobial stewardship program (ASP) review. LRTI prescriptions were compared to IDSA recommendations for community-acquired pneumonia. Neonatal prescriptions were compared to recommendations from the American Academy of Pediatrics (AAP). Prescriptions were categorized as optimal (80%-120% of recommended dosing), suboptimal (\u3c80% of recommended dosing), or excessive (\u3e120% of recommended dosing). RESULTS: Among 1,038 ampicillin prescriptions, we analyzed 88 prescriptions for LRTI, 499 prescriptions for neonatal sepsis, and 27 prescriptions for neonatal CNS infection. Of the LRTI prescriptions, 77.3%were optimal. Of prescriptions for neonatal sepsis, 81.6% were excessive compared to AAP bacteremia recommendations but 78.8% were suboptimal compared to AAP meningitis guidelines. Also, 48.1% of prescriptions for neonatal CNS infection were suboptimal, and 50.6% of prescriptions were not reviewed by the ASP. CONCLUSIONS: LRTI dosing is generally within the IDSA-recommended range. However, dosing for neonatal sepsis often exceeds the recommendation for bacteremia but is below the recommendation for meningitis. This variability points to an important opportunity for future antimicrobial stewardship efforts

Management of Cancer-Related Anemia with Erythropoietic Agents: Doubts, Certainties, and Concerns

Abstract The management of cancer-related anemia with erythropoietic agents presents many unresolved issues. We reviewed the literature relating to epoetin alfa (Eprex®/Epypo®; Ortho Biotech/Janssen-Cilag, High Wycombe, United Kingdom, http://www.orthobiotech.co.uk; Procrit®; Ortho Biotech Products, L.P., Bridgewater, NJ, http://www.orthobiotech.com), epoetin beta (NeoRecormon®; Hoffman-La Roche, Basel, Switzerland, http://www.roche.com), and darbepoetin alfa (Aranesp®; Amgen Inc., Thousand Oaks, CA, http://www.amgen.com) highlighting the results of published clinical trials, safety, and cost-effectiveness. Studies were identified through MEDLINE and the bibliographies of relevant articles. Epoetin alfa, epoetin beta, and darbepoetin alfa have differing pharmacokinetic and pharmacodynamic profiles. They are all effective at reducing transfusion requirements and improving health-related quality-of-life parameters, irrespective of tumor response. A direct comparison between epoetin alfa and darbe poetin alfa is based on limited evidence, which does not allow definitive conclusions about relative efficacy and cost-effectiveness. No predictive factors for response to erythropoietic agents have been validated in prospective trials. The most consistent adverse events are thrombotic and may occur irrespective of an increase in hemoglobin. Recent research indicates that the erythropoietin receptor is expressed in several cancer cell lines, raising the concern of possible stimulation of tumor cell growth by these drugs. Studies on the cost-effectiveness of erythropoietins, particularly compared with transfusion therapy, have been challenging to conduct and analyze and have generated ambiguous results. The use of erythropoietins needs to be optimized in terms of cost-effectiveness, and issues surrounding safety need to be clarified. A stronger methodology for clinical studies and the design of new, randomized, clinical trials is a major priority

Soft and flexible poly(ethylene glycol) nanotubes for local drug delivery

Nanotubes are emerging as promising materials for healthcare applications but the selection of clinically relevant starting materials for their synthesis remains largely unexplored. Here we present, for the first time, the synthesis of poly(ethylene glycol) (PEG) based nanotubes via the photopolymerization of poly(ethylene glycol) diacrylate and other diacrylate derivatives within the pores of anodized aluminum oxide templates. Template-assisted synthesis allowed the manufacture of a diverse set of polymeric nanotubes with tunable physical characteristics including diameter (∼200–400 nm) and stiffness (405–902 kPa). PEG nanotubes were subjected to cytotoxicty assessment in cell lines and primary stem cells and showed excellent cytocompatability (IC50 > 120 μg ml−1). Nanotubes were readily drug loaded but released the majority of the drug over 5 days. Direct administration of drug loaded nanotubes to human orthotopic breast tumors substantially reduced tumor growth and metastasis and outperformed i.v. administration at the equivalent dose. Overall, this nanotube templating platform is emerging as a facile route for the manufacture of poly(ethylene glycol) nanotubes

Application of an antibiotic spectrum index in the neonatal intensive care unit

Antimicrobial stewardship programs typically use days of therapy to assess antimicrobial use. However, this metric does not account for the antimicrobial spectrum of activity. We applied an antibiotic spectrum index to a population of very-low-birth-weight infants to assess its utility to evaluate the impact of antimicrobial stewardship interventions

Accelerating growth of HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane) in the atmosphere

We report the first measurements of 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), a substitute for ozone depleting compounds, in air samples originating from remote regions of the atmosphere and present evidence for its accelerating growth. Observed mixing ratios ranged from below 0.01 ppt in deep firn air to 0.59 ppt in the current northern mid-latitudinal upper troposphere. Firn air samples collected in Greenland were used to reconstruct a history of atmospheric abundance. Year-on-year increases were deduced, with acceleration in the growth rate from 0.029 ppt per year in 2000 to 0.056 ppt per year in 2007. Upper tropospheric air samples provide evidence for a continuing growth until late 2009. Furthermore we calculated a stratospheric lifetime of 370 years from measurements of air samples collected on board high altitude aircraft and balloons. Emission estimates were determined from the reconstructed atmospheric trend and suggest that current "bottom-up" estimates of global emissions for 2005 are too high by a factor of three

Psychosocial work environment stressors for school staff during the COVID-19 pandemic: Barriers and facilitators for supporting wellbeing

INTRODUCTION: After periods of remote and/or hybrid learning as a result of the COVID-19 global pandemic, the return to in-person learning has been beneficial for both students and teachers, but it has not been without challenges. This study was designed to assess the impact of the return to in-person learning on the school experience, and efforts made to ease the transition in furthering a positive in-person learning environment. MATERIALS AND METHODS: We conducted a series of listening sessions with 4 stakeholder groups: students ( RESULTS: Three main themes emerged around school staff experiences: (1) increased levels of stress and anxiety manifested in key ways, including students\u27 challenges with personal behavior management contributing to increased aggression and staff shortages; (2) school staff described key contributors to stress and anxiety, including feeling excluded from decision making and challenges with clear and consistent communication; and (3) school staff described key facilitators that supported their management of anxiety and stress, including adaptability, heightened attention and resources to wellbeing, and leveraging interpersonal relationships. DISCUSSION: School staff and students faced significant stress and anxiety during the 2021-2022 school year. Further exploration and identification of approaches to mitigate key contributors to increased stress and anxiety for school staff, along with increased opportunities for implementing key facilitators that were identified as important in managing and navigating the increased stress and anxiety offer valuable opportunities for helping to create a supportive work environment for school staff in the future