Effects of temperature and salinity on four species of northeastern Atlantic scyphistomae (Cnidaria Scyphozoa)

This work was funded by the MASTS pooling initiative (Marine Alliance for Science and Technology for Scotland), and we gratefully acknowledge that support. MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions. C.L.W. is also grateful to the US/UK Fulbright Commission and the University of St Andrews for their financial support.Laboratory incubation experiments were conducted to examine the effects of different temperatures (4, 9, 14, 19, 23°C) and salinities (21, 27, 34) on survival and asexual reproduction of scyphistomae of Cyanea capillata, C. lamarckii, Chrysaora hysoscella, and Aurelia aurita in order to better understand how climate variability may affect the timing and magnitude of jellyfish blooms. Significant mortality was observed only for C. capillata and Ch. hysoscella at the highest and lowest temperatures, respectively, but temperature and salinity significantly affected the asexual reproductive output for all species. As temperature increased, production rates of podocysts increased and, if produced, progeny scyphistomae by side budding also increased. However, strobilation rates, and therefore the mean number of ephyrae produced, decreased when scyphistomae were exposed to elevated temperatures. These results provide a mechanistic explanation for why ephyrae of these species tend to be produced during colder periods of the year whilst summer and early autumn are probably important periods for increasing the numbers of scyphistomae in natural populations.PostprintPeer reviewe

Experimental validation of a fast-tracking FOCV-MPPT circuit for a wave energy converter embedded into an oceanic drifter

Wave Energy Converters (WECs) are an ideal solution for expanding the autonomy of surface sensor platforms such as oceanic drifters. To extract the maximum amount of energy from these fast-varying sources, a fast maximum power point tracking (MPPT) technique is required. Previous studies have examined power management units (PMU) with fast MPPT circuits, but none of them have demonstrated their feasibility in a real-world scenario. In this study, the performance of a fast-tracking fractional open circuit voltage (FOCV)-MPPT circuit (sampling period TMPPT of 48 ms) is compared with a commercial slow-tracking PMU (TMPPT of 16 s) in a monitored sea area while using a small-scale, pendulum-type WEC. A specific low-power relaxation oscillator circuit is designed to control the fast MPPT circuit. The results demonstrate that by speeding up the sampling frequency of the MPPT circuit, the harvested energy can be increased by a factor of three.The first author was supported by the European Union—NextGenerationEU and the Ministerio de Universidades—Plan de Recuperación, Transformación y Resiliencia under a Margarita Salas post-doctoral research fellowship (ref. 2022UPC-MSC-94068). This work was partially supported by the project MELOA from the European Commission’s Horizon 2020 research and Innovation program under Grant Agreement No. 776280. This study was developed using the framework of the Research Unit Tecnoterra (ICM-CSIC/UPC) and the following project activities: PLOME (PLEC2021-007525; Ministerio de Ciencia e Innovación) and BITER (PID2020-114732RB-C32; Ministerio de Ciencia e Innovación).Peer ReviewedPostprint (published version

Surveillance quality correlates with surgical site infection rates in knee and hip arthroplasty and colorectal surgeries: A call to action to adjust reporting of SSI rates.

OBJECTIVE The incidence of surgical site infections may be underreported if the data are not routinely validated for accuracy. Our goal was to investigate the communicated SSI rate from a large network of Swiss hospitals compared with the results from on-site surveillance quality audits. DESIGN Retrospective cohort study. PATIENTS In total, 81,957 knee and hip prosthetic arthroplasties from 125 hospitals and 33,315 colorectal surgeries from 110 hospitals were included in the study. METHODS Hospitals had at least 2 external audits to assess the surveillance quality. The 50-point standardized score per audit summarizes quantitative and qualitative information from both structured interviews and a random selection of patient records. We calculated the mean National Healthcare Safety Network (NHSN) risk index adjusted infection rates in both surgery groups. RESULTS The median NHSN adjusted infection rate per hospital was 1.0% (interquartile range [IQR], 0.6%-1.5%) with median audit score of 37 (IQR, 33-42) for knee and hip arthroplasty, and 12.7% (IQR, 9.0%-16.6%), with median audit score 38 (IQR, 35-42) for colorectal surgeries. We observed a wide range of SSI rates and surveillance quality, with discernible clustering for public and private hospitals, and both lower infection rates and audit scores for private hospitals. Infection rates increased with audit scores for knee and hip arthroplasty (P value for the slope = .002), and this was also the case for planned (P = .002), and unplanned (P = .02) colorectal surgeries. CONCLUSIONS Surveillance systems without routine evaluation of validity may underestimate the true incidence of SSIs. Audit quality should be taken into account when interpreting SSI rates, perhaps by adjusting infection rates for those hospitals with lower audit scores

Structure and consistency of self-reported social contact networks in British secondary schools.

Self-reported social mixing patterns are commonly used in mathematical models of infectious diseases. It is particularly important to quantify patterns for school-age children given their disproportionate role in transmission, but it remains unclear how the structure of such social interactions changes over time. By integrating data collection into a public engagement programme, we examined self-reported contact networks in year 7 groups in four UK secondary schools. We collected data from 460 unique participants across four rounds of data collection conducted between January and June 2015, with 7,315 identifiable contacts reported in total. Although individual-level contacts varied over the study period, we were able to obtain out-of-sample accuracies of more than 90% and F-scores of 0.49-0.84 when predicting the presence or absence of social contacts between specific individuals across rounds of data collection. Network properties such as clustering and number of communities were broadly consistent within schools between survey rounds, but varied significantly between schools. Networks were assortative according to gender, and to a lesser extent school class, with the estimated clustering coefficient larger among males in all surveyed co-educational schools. Our results demonstrate that it is feasible to collect longitudinal self-reported social contact data from school children and that key properties of these data are consistent between rounds of data collection

Antimicrobial prophylaxis administration after umbilical cord clamping in cesarean section and the risk of surgical site infection: a cohort study with 55,901 patients.

BACKGROUND The World Health Organization (WHO) recommends administration of surgical antimicrobial prophylaxis (SAP) in cesarean section prior to incision to prevent surgical site infections (SSI). This study aimed to determine whether SAP administration following cord clamping confers an increased SSI risk to the mother. METHODS Study design: Cohort. SETTING 75 participating Swiss hospitals, from 2009 to 2018. PARTICIPANTS A total of 55,901 patients were analyzed. MAIN OUTCOME MEASURES We assessed the association between SAP administration relative to incision and clamping and the SSI rate, using generalized linear multilevel models, adjusted for patient characteristics, procedural variables, and health-care system factors. RESULTS SAP was administered before incision in 26'405 patients (47.2%) and after clamping in 29,496 patients (52.8%). Overall 846 SSIs were documented, of which 379 (1.6% [95% CI, 1.4-1.8%]) occurred before incision and 449 (1.7% [1.5-1.9%]) after clamping (p = 0.759). The adjusted odds ratio for SAP administration after clamping was not significantly associated with an increased SSI rate (1.14, 95% CI 0.96-1.36; p = 0.144) when compared to before incision. Supplementary and subgroup analyses supported these main results. CONCLUSIONS This study did not confirm an increased SSI risk for the mother in cesarean section if SAP is given after umbilical cord clamping compared to before incision

Catheter-related infections: does the spectrum of microbial causes change over time? A nationwide surveillance study

Objectives To estimate the incidence and epidemiology of catheter-related bloodstream infections (CRBSIs) on a national scale by using prospective epidemiological data from the Swiss Antibiotic Resistance Surveillance System (ANRESIS). Design Observational study. Setting National surveillance from 2008 to 2015 of acute hospitals in Switzerland. Participants We included acute Swiss hospitals that sent blood cultures and catheter tip culture results on a regular basis during the entire study period to the ANRESIS database. Outcome measure A catheter-related bloodstream infection (termed ‘modified CRBSI’, mCRBSI) was defined as isolating the same microorganism with identical antibiogram from ≥1 blood cultures (performed ±7 days around the catheter removal) as the one recovered from the catheter tip. Incidence rates of mCRBSI were calculated per 1000 admissions. Results From 2008 to 2015, the mCRBSI incidence rate decreased from 0.83 to 0.58 episodes/1000 admissions (−6% per year, p<0.001). Coagulase-negative staphylococci, Staphylococcus aureus and fungi all exhibited decreasing trends, while rates of enterococci and Gram-negative bacteria remained stable. Conclusions The overall incidence of mCRBSI in Switzerland is decreasing; however, the incidence of mCRBSI due to Enterococci and Gram-negative micro-organisms did not change over time. These pathogens may grow in importance in catheter-related infections, which would have clinical implications for the choice of empirical treatment

Better Operating Room Ventilation as Determined by a Novel Ventilation Index is Associated with Lower Rates of Surgical Site Infections.

OBJECTIVE To assess the impact of operating room (OR) ventilation quality on surgical site infections (SSI) using a novel ventilation index. SUMMARY BACKGROUND DATA Previous studies compared laminar air flow with conventional ventilation, thereby ignoring many parameters that influence air flow properties. METHODS In this cohort study, we surveyed hospitals participating in the Swiss SSI surveillance and calculated a ventilation index for their ORs, with higher values reflecting less turbulent air displacement. For procedures captured between 01/2017-12/2019, we studied the association between ventilation index and SSI rates using linear regression (hospital-level analysis) and with the individual SSI risk using generalized linear mixed-effects models (patient-level analysis). RESULTS We included 47 hospitals (182 ORs). Among the 163'740 included procedures, 6791 SSIs were identified. In hospital-level analyses, a 5-unit increase in the ventilation index was associated with lower SSI rates for knee and hip arthroplasty (-0.41 infections per 100 procedures, CI -0.69 to -0.13), cardiac (-0.89, -1.91 to 0.12), and spine surgeries (-1.15, -2.56 to 0.26). Similarly, patient-level analyses showed a lower SSI risk with each 5-unit increase in ventilation index (adjusted odds ratio 0.71, CI 0.58 to 0.87 for knee and hip; 0.72, 0.49 to 1.06 for spine; 0.82, 0.69 to 0.98 for cardiac surgery). Higher index values were mainly associated with a lower risk for superficial and deep incisional SSIs. CONCLUSIONS Better ventilation properties, assessed with our ventilation index, are associated with lower rates of superficial and deep incisional SSIs in orthopedic and cardiac procedures. OR ventilation quality appeared to be less relevant for other surgery types

Better operating room ventilation as determined by a novel ventilation index is associated with lower rates of surgical site infections

OBJECTIVE: The aim was to assess the impact of operating room (OR) ventilation quality on surgical site infections (SSIs) using a novel ventilation index. BACKGROUND: Previous studies compared laminar air flow with conventional ventilation, thereby ignoring many parameters that influence air flow properties. METHODS: In this cohort study, we surveyed hospitals participating in the Swiss SSI surveillance and calculated a ventilation index for their ORs, with higher values reflecting less turbulent air displacement. For procedures captured between January 2017 and December 2019, we studied the association between ventilation index and SSI rates using linear regression (hospital-level analysis) and with the individual SSI risk using generalized linear mixed-effects models (patient-level analysis). RESULTS: We included 47 hospitals (182 ORs). Among the 163,740 included procedures, 6791 SSIs were identified. In hospital-level analyses, a 5-unit increase in the ventilation index was associated with lower SSI rates for knee and hip arthroplasty (-0.41 infections per 100 procedures, 95% confidence interval: -0.69 to -0.13), cardiac (-0.89, -1.91 to 0.12), and spine surgeries (-1.15, -2.56 to 0.26). Similarly, patient-level analyses showed a lower SSI risk with each 5-unit increase in ventilation index (adjusted odds ratio 0.71, confidence interval: 0.58-0.87 for knee and hip; 0.72, 0.49-1.06 for spine; 0.82, 0.69-0.98 for cardiac surgery). Higher index values were mainly associated with a lower risk for superficial and deep incisional SSIs. CONCLUSIONS: Better ventilation properties, assessed with our ventilation index, are associated with lower rates of superficial and deep incisional SSIs in orthopedic and cardiac procedures. OR ventilation quality appeared to be less relevant for other surgery types