Descriptions of the setae on the pereiopods of scyllarid lobsters, Scyllarides aequinoctialis, S. latus, and S. nodifer, with observations on the feeding sequence during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster feeding have remained largely unexplored. Using Scanning Electron Microscopy (SEM), the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters: Scyllarides aequinoctialis, S. latus, and S. nodifer. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in S. aequinoctialis only. Comparisons among species demonstrate that S. nodifer bears the same setae and setal pattern as S. latus, but S. aequinoctialis differs. The setal patterns of slipper lobsters contrast with those of nephropid and palinurid lobsters, likely due to the more rigorous use of the pereiopods in accessing their food. Feeding sequences of S. aequinoctialis on bivalves were videotaped, analyzed as Markovian chains, and showed a complex suite of behaviors involving contact chemoreception by the antennules as part of an initial assessment of food items, followed by mouthpart and leg probing, and eventual wedging behavior as previously described for S. squammosus. Feeding sequences of S. latus on gastropods and bivalves also demonstrate extensive use of the pereiopods (instead of the mouthparts) first to pry these prey items from the substrate and then to remove the foot. Use of antennules for food assessment and recruitment of many of the perieopods for food handling with minimal use of mouthparts also contrasts with the feeding sequences typical of nephropid and palinurid lobsters and may be an important adaptation

Description of pereiopod setae of scyllarid lobsters, Scyllarides aequinoctialis, Scyllarides latus, and Scyllarides nodifer, with observations on the feeding during consumption of bivalves and gastropods

The morphological and behavioral aspects of slipper lobster (Scyllaridae) feeding have remained largely unexplored. Using scanning electron microscopy, the gross morphological structure of all segments of the pereiopods were described for three species of scyllarid lobsters. Five types of setae within three broad categories were found: simple (long and miniature), cuspidate (robust and conate), and teasel (a type of serrulate setae). Setae were arranged in a highly-organized, row-like pattern on the ventral and dorsal surfaces. Cuspidate setae were found on all surfaces of all segments. Simple setae were found only on the dactyl, whereas teazel setae were concentrated on the lateral-most edge of the alate carina on the merus in only one species [Scyllarides aequinoctialis (Lund, 1793)]; this species also differed from the other two [Scyllarides nodifer (Stimpson, 1866), Scyllarides latus (Latreille, 1803)] in setal patterning. All examined slipper lobsters differed in setal types and patterns from nephropid and palinurid lobsters, likely due to the more rigorous use of their pereiopods in accessing food. Feeding sequences of two of the slipper lobster species were videotaped and analyzed, and demonstrated a complex set of behaviors involving contact chemoreception by the antennules as part of an initial assessment of the food item, followed by extensive manipulation, probing, and eventual wedging behavior by the pereiopods as previously described for Scyllarides. Use of the antennules for food assessment and heavy reliance on the pereiopods, rather than the mouthparts, for food handling contrasts with nephropid and palinurid lobsters.https://doi.org/10.5343/bms.2017.1125Published versio

Investigating Content Multidimensionality in a Large-scale Science Assessment: A Mixed Methods Approach

Science, Technology, Engineering, and Math (STEM) skills are increasingly required of students to be successful in higher education and the workforce. Therefore, modeling assessment outcomes accurately, often using more types of student data to get a complete picture of student learning, is increasingly relevant. The Program for International Student Assessment (PISA) is promoted as a summative assessment opportunity that includes a science framework. As with many science assessments, the framework includes Life, Physical, and Earth science, which alone seems to imply multidimensionality, and also there are other sources of dimensionality that seem to be described conceptually in the framework. Using data from the 2015 PISA science assessment, a multidimensional item response theory (MIRT) model was fit to see how a multidimensional model operates with the data. Before developing the MIRT model, a qualitative review of the framework for multidimensionality took place and exploratory analyses were implemented for the quantitative data, including a data science technique to explore multidimensionality and some factor analysis techniques. After fitting the MIRT model, it was compared to several unidimensional IRT (UIRT) models to determine the model that explains the most variation. The qualitative analyses generated evidence of multidimensional science content domains in the 2015 PISA science framework, which should require a MIRT model, but quantitative analyses indicate a unidimensional model is more practically significant. Once quantitative results were triangulated with the qualitative review of the framework for multidimensionality, the implications on equity and history of harm with regards to science assessments were discussed. Findings from the qualitative and quantitative aspects of the study were used to generate recommendations for different stakeholders

Description of the Setae on the Pereiopods of the Mediterranean Slipper Lobster Scyllarides latus, the Ridged Slipper Lobster, S Nodifer and the Spanish Slipper Lobster S Aequinoctialis

This study describes the morphology of setae on the five pairs of pereiopods (walking legs) of three species of scyllarid lobsters. Setae were examined using scanning electron microscopy and environmental scanning electron microscopy, with their location being directly mapped for five segments of the endopod (dactyl, propus, carpus, merus and ischium) of each of the pereiopods. Using Watling’s (1989) scheme for setal morphology, five types of setae were found; cuspidate, simple, conate, miniature simple and teazel. Setae were found to have a highly organized row-like pattern on the ventral (aboral) and dorsal (oral) surfaces of the pereiopods Cuspidate setae were found on all surfaces and faces of the dactyl, propus, carpus, merus and ischium segments of each of the five pereiopods examined. Simple setae were found only on the dactyl of each pereiopod, and the teazel setae were concentrated on the rim, the lateral most edge of the merus shield, for S. aequinoctialis only. Comparisons of setal types between the species demonstrate that S. nodifer bears the exact same setae and setal pattern as S. lotus, while S. aequinoctialis shows slight differences. Based on comparisons between the more intensely studied nephropid (clawed lobsters) and palinurid (spiny lobsters) species, scyllarids (slipper lobsters) have fewer setae on their pereiopods, probably due to the abrasive manner in which they manipulate and open their preferred food (clams, oysters, mussels).Biolog

An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients

International audienceAbstract Background Heterogeneous respiratory system static compliance ( C RS ) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level. Methods We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe C RS —calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]—and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide. Results We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of C RS within the first seven days of MV. Median (IQR) age was 62 (52–71), patients were predominantly males (68%) and from Europe/North and South America (88%). C RS , within 48 h from endotracheal intubation, was available in 649 patients and was neither associated with the duration from onset of symptoms to commencement of MV ( p = 0.417) nor with PaO 2 /FiO 2 ( p = 0.100). Females presented lower C RS than males (95% CI of C RS difference between females-males: − 11.8 to − 7.4 mL/cmH 2 O p < 0.001), and although females presented higher body mass index (BMI), association of BMI with C RS was marginal ( p = 0.139). Ventilatory management varied across C RS range, resulting in a significant association between C RS and driving pressure (estimated decrease − 0.31 cmH 2 O/L per mL/cmH 2 0 of C RS , 95% CI − 0.48 to − 0.14, p < 0.001). Overall, 28-day ICU mortality, accounting for the competing risk of being discharged within the period, was 35.6% (SE 1.7). Cox proportional hazard analysis demonstrated that C RS (+ 10 mL/cm H 2 O) was only associated with being discharge from the ICU within 28 days (HR 1.14, 95% CI 1.02–1.28, p = 0.018). Conclusions This multicentre report provides a comprehensive account of C RS in COVID-19 patients on MV. C RS measured within 48 h from commencement of MV has marginal predictive value for 28-day mortality, but was associated with being discharged from ICU within the same period. Trial documentation: Available at https://www.covid-critical.com/study . Trial registration : ACTRN12620000421932

An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients

Abstract Background Heterogeneous respiratory system static compliance (CRS) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level. Methods We designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe CRS—calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]—and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide. Results We studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of CRS within the first seven days of MV. Median (IQR) age was 62 (52–71), patients were predominantly males (68%) and from Europe/North and South America (88%). CRS, within 48 h from endotracheal intubation, was available in 649 patients and was neither associated with the duration from onset of symptoms to commencement of MV (p = 0.417) nor with PaO2/FiO2 (p = 0.100). Females presented lower CRS than males (95% CI of CRS difference between females-males: − 11.8 to − 7.4 mL/cmH2O p &lt; 0.001), and although females presented higher body mass index (BMI), association of BMI with CRS was marginal (p = 0.139). Ventilatory management varied across CRS range, resulting in a significant association between CRS and driving pressure (estimated decrease − 0.31 cmH2O/L per mL/cmH20 of CRS, 95% CI − 0.48 to − 0.14, p &lt; 0.001). Overall, 28-day ICU mortality, accounting for the competing risk of being discharged within the period, was 35.6% (SE 1.7). Cox proportional hazard analysis demonstrated that CRS (+ 10 mL/cm H2O) was only associated with being discharge from the ICU within 28 days (HR 1.14, 95% CI 1.02–1.28, p = 0.018). Conclusions This multicentre report provides a comprehensive account of CRS in COVID-19 patients on MV. CRS measured within 48 h from commencement of MV has marginal predictive value for 28-day mortality, but was associated with being discharged from ICU within the same period. Trial documentation: Available at https://www.covid-critical.com/study. Trial registration: ACTRN12620000421932. </jats:sec

Impact of Hemoglobin Levels on Composite Cardiac Arrest or Stroke Outcome in Patients With Respiratory Failure Due to COVID-19

OBJECTIVES:. Anemia has been associated with an increased risk of both cardiac arrest and stroke, frequent complications of COVID-19. The effect of hemoglobin level at ICU admission on a composite outcome of cardiac arrest or stroke in an international cohort of COVID-19 patients was investigated. DESIGN:. Retrospective analysis of prospectively collected database. SETTING:. A registry of COVID-19 patients admitted to ICUs at over 370 international sites was reviewed for patients diagnosed with cardiac arrest or stroke up to 30 days after ICU admission. Anemia was defined as: normal (hemoglobin ≥ 12.0 g/dL for women, ≥ 13.5 g/dL for men), mild (hemoglobin 10.0–11.9 g/dL for women, 10.0–13.4 g/dL for men), moderate (hemoglobin ≥ 8.0 and < 10.0 g/dL for women and men), and severe (hemoglobin < 8.0 g/dL for women and men). PATIENTS:. Patients older than 18 years with acute COVID-19 infection in the ICU. INTERVENTIONS:. None. MEASUREMENTS AND MAIN RESULTS:. Of 6926 patients (median age = 59 yr, male = 65%), 760 patients (11.0%) experienced stroke (2.0%) and/or cardiac arrest (9.4%). Cardiac arrest or stroke was more common in patients with low hemoglobin, occurring in 12.8% of patients with normal hemoglobin, 13.3% of patients with mild anemia, and 16.7% of patients with moderate/severe anemia. Time to stroke or cardiac arrest by anemia status was analyzed using Cox proportional hazards regression with death as a competing risk. Covariates selected through clinical knowledge were age, sex, comorbidities (diabetes, hypertension, obesity, and cardiac or neurologic conditions), pandemic era, country income, mechanical ventilation, and extracorporeal membrane oxygenation. Moderate/severe anemia was associated with a higher risk of cardiac arrest or stroke (hazard ratio, 1.32; 95% CI, 1.05–1.67). CONCLUSIONS:. In an international registry of ICU patients with COVID-19, moderate/severe anemia was associated with increased hazard of cardiac arrest or stroke

Early short course of neuromuscular blocking agents in patients with COVID-19 ARDS: a propensity score analysis

Abstract Background The role of neuromuscular blocking agents (NMBAs) in coronavirus disease 2019 (COVID-19) acute respiratory distress syndrome (ARDS) is not fully elucidated. Therefore, we aimed to investigate in COVID-19 patients with moderate-to-severe ARDS the impact of early use of NMBAs on 90-day mortality, through propensity score (PS) matching analysis. Methods We analyzed a convenience sample of patients with COVID-19 and moderate-to-severe ARDS, admitted to 244 intensive care units within the COVID-19 Critical Care Consortium, from February 1, 2020, through October 31, 2021. Patients undergoing at least 2 days and up to 3 consecutive days of NMBAs (NMBA treatment), within 48 h from commencement of IMV were compared with subjects who did not receive NMBAs or only upon commencement of IMV (control). The primary objective in the PS-matched cohort was comparison between groups in 90-day in-hospital mortality, assessed through Cox proportional hazard modeling. Secondary objectives were comparisons in the numbers of ventilator-free days (VFD) between day 1 and day 28 and between day 1 and 90 through competing risk regression. Results Data from 1953 patients were included. After propensity score matching, 210 cases from each group were well matched. In the PS-matched cohort, mean (± SD) age was 60.3 ± 13.2 years and 296 (70.5%) were male and the most common comorbidities were hypertension (56.9%), obesity (41.1%), and diabetes (30.0%). The unadjusted hazard ratio (HR) for death at 90 days in the NMBA treatment vs control group was 1.12 (95% CI 0.79, 1.59, p = 0.534). After adjustment for smoking habit and critical therapeutic covariates, the HR was 1.07 (95% CI 0.72, 1.61, p = 0.729). At 28 days, VFD were 16 (IQR 0–25) and 25 (IQR 7–26) in the NMBA treatment and control groups, respectively (sub-hazard ratio 0.82, 95% CI 0.67, 1.00, p = 0.055). At 90 days, VFD were 77 (IQR 0–87) and 87 (IQR 0–88) (sub-hazard ratio 0.86 (95% CI 0.69, 1.07; p = 0.177). Conclusions In patients with COVID-19 and moderate-to-severe ARDS, short course of NMBA treatment, applied early, did not significantly improve 90-day mortality and VFD. In the absence of definitive data from clinical trials, NMBAs should be indicated cautiously in this setting. </jats:sec