Mortality in Catalonia during the summer of 2022 and its relation with high temperatures and COVID-19 cases.

Purpose: To analyse the association between the mortality during the summer 2022 and either high temperatures or the COVID-19 wave with data from the Catalan Health Care System (7.8 million people).

Methods: We performed a retrospective study using publicly available data of meteorological variables, influenza-like illness (ILI) cases (including COVID-19) and deaths.

Multisystem inflammatory syndrome in children and SARS-CoV-2 variants: a two-year ambispective multicentric cohort study in Catalonia, Spain.

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe disease temporarily related to SARS-CoV-2. We aimed to describe the epidemiological, clinical, and laboratory findings of all MIS-C cases diagnosed in children < 18 years old in Catalonia (Spain) to study their trend throughout the pandemic. This was a multicenter ambispective observational cohort study (April 2020-April 2022).

Multisystem Inflammatory Syndrome in Children in Western Countries? Decreasing Incidence as the Pandemic Progresses?: An Observational Multicenter International Cross-sectional Study.

Background: SARS-CoV-2 variations as well as immune protection after previous infections and/or vaccination may have altered the incidence of multisystemic inflammatory syndrome in children (MIS-C). We aimed to report an international time-series analysis of the incidence of MIS-C to determine if there was a shift in the regions or countries included into the study.

Methods: This is a multicenter, international, cross-sectional study.

Symptom-Based Predictive Model of COVID-19 Disease in Children.

Background: Testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is neither always accessible nor easy to perform in children. We aimed to propose a machine learning model to assess the need for a SARS-CoV-2 test in children (<16 years old), depending on their clinical symptoms.

Methods: Epidemiological and clinical data were obtained from the REDCap registry.

Schools as a Framework for COVID-19 Epidemiological Surveillance of Children in Catalonia, Spain: A Population-Based Study.

We describe and analyze the childhood (<18 years) COVID-19 incidence in Catalonia, Spain, during the first 36 weeks of the 2020-2021 school-year and to compare it with the incidence in adults. Data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) tests were obtained from the Catalan Agency for Quality and Health Assessment. Overall, 7,203,663 SARS-CoV-2 tests were performed, of which 491,819 were positive (6.

Comparison of ultradian and circadian oscillations of carbon dioxide production by various endotherms.

Carbon dioxide emission (VCO2) was computed every 20 min from continuous CO2 concentration recordings taken during 3-30 consecutive days, in strictly controlled environmental conditions, in 54 OF1 mice, 99 Japanese quail, 66 Sprague-Dawley rats, 50 Hartley guinea pigs, 7 chicks, for 7-15 days on 2 Cynomolgus monkeys, and for 24 h on 7 premature infants. This VCO2 shows circadian and ultradian oscillations that were analyzed for frequencies and amplitudes in light-dark 12-h alternation (LD 12:12), continuous light (LL), and continuous dark (DD). Circadians were not always identified or were often masked in LL or DD (mostly in guinea pigs, quail, and rats), while ultradians (tau > or = 40 min) were found in all species, at every time, and in all light regimens.

Rats grouping and the circadian and ultradian synchronization of their carbon dioxide emission by a light-dark 12:12 h alternation.

Carbon dioxide emission (VCO2) was continuously recorded during 19 consecutive days in 25 Sprague Dawley young male rats placed in the same "respiratory chamber", grouped by 5 (G) and then separated (S). All rats were in controlled environmental conditions (20 degrees C temperature, humidity, ventilation, food and water ad libitum) and submitted to a light (100 lux)-dark alternation (LD 12:12). The curves obtained with the respiratory chamber CO2 concentration sampled every 20 minutes were analyzed for circadian periods, amplitudes, phases, ultradian peak oscillation intervals and amplitudes, and VCO2 time variations at L-->D and D-->L light transitions.

Ultradian and circadian compartmentalization of respiratory and metabolic exchanges in small laboratory vertebrates.

Carbon dioxide emission (VCO2) taken as an index of respiratory and metabolic exchanges, was continuously recorded during 4-30 consecutive days in 100 quail, 87 chicks, 347 rats, 665 mice and 70 guinea-pigs which were under controlled environmental parameters. Harmonic analysis, fast Fourier transform, chi-square periodograms, peak and trough intervals were computed with VCO2 values obtained with CO2 concentrations sampled every 20 min on the CO2 recordings. In LD 12:12 alternation, circadian rhythms were observed in all quail, chicks, rats and mice, but only in 80% of the guinea-pigs.

Societal synchronization in groups of rats or quail submitted to various lighting regimens.

Groups of rats or of quail that had been previously synchronized in a light (L = 100 lux) dark (D) phase opposition (PO = LD and DL) were placed together in a L12:D12 or D12:L12 alternation or in continuous light (LL) or continuous darkness (DD). Emission of carbon dioxide (VCO2) which was continuously recorded in groups of individuals placed in respiratory chambers under controlled environmental conditions allows an index of their overall respiratory and metabolic exchanges to be found. In PO animals placed in LD or DL, the VCO2 circadian light dark synchronization comes back less quickly in rats than in quail, and the VCO2 variations at the light dark transitions (L-D and D-L) remain unchanged in rats, but are modified in quail.

Ultradian and circadian CO2 emission variations in nocturnal and diurnal animals exposed to a light stimulus.

1. Carbon dioxide emission (VCO2) has been continuously recorded in three laboratory animal species (Sprague-Dawley rats, Japanese quail, Hartley guinea-pigs) which differ by their nocturnal and diurnal activities. A 100 lux stimulus has been delivered at various time intervals.

Sexual phenotype of avian chimeric gonads with germinal and stromal cells of opposite genetic sexes.

The respective roles of germinal and stromal cells in determining the sexual phenotype of the gonad were analyzed in chimeric gonads obtained by surgical recombination between young avian blastodiscs in ovo. Equivalent territories were exchanged between two blastodisc, in order that the germinal crescent and the gonad territory had a different origin (fig. 3).

Periodic analysis of ultradian (40 min less than tau less than 24h) respiratory variations in laboratory vertebrates of various circadian activities.

Continuous recordings of respiratory gas exchanges of various laboratory endotherm vertebrate species, which have either a nocturnal (mouse, rat) or diurnal (monkey, quail, chicken) or equivocal (guinea-pig) maximal activity, kept under controlled environmental conditions of temperature, humidity, ventilation and provided with food and water ad libitum, show ultradian oscillations of mean and low frequencies (1 less than f less than 35 c.day-1). Harmonic analysis was used to assess periodic or random ultradian variations and to compute amplitudes and phases of these oscillations when these vertebrates were submitted to a light (100 lx) and dark circadian alteration (LD 12:12).

Biological parameters in Japanese quail genetically selected for resistance or sensitivity to an acute hypoxic survival.

Various biological parameters were measured in two strains of Japanese quail selected for their resistance (Ls+) or susceptibility (Ls-) to an acute normobaric hypoxic challenge. Adults of these two strains showed very little or no significant differences concerning body weights, carbon dioxide emission, photoperiodic (L----D and D----L) respiratory reactions, cloacal temperatures, heart rates and ECG QRSII amplitudes, red blood cell data, hemoglobin electrophoresis, and plasma corticosterone (before and after an hypoxic challenge). Enzymatic capacities of phosphofructo-and pyruvate kinases, of glucose-6-phosphatase, lactico- and malate-dehydrogenases, measured in brains and hearts, showed but few statistically significant differences.

Ultradian and circadian respiratory rhythms in grouped small laboratory vertebrate species as a method to assess the effects of environmental challenges.

The recording over several days of the respiratory gases of groups of different laboratory vertebrates (mice, rats, quails), placed in a chamber with controlled ventilation, and in standardized environmental conditions of temperature, humidity, light, noise and feeding, shows ultradian (tau less than 24 hr) and circadian (tau congruent to 24 hr) rhythms. A simple variance analysis method shows periodic carbon dioxide changes, due to different environmental stimuli. Societal, light, acoustical, carbon monoxide and starvation challenges are given as examples.

Evidence of genetic differences in acute hypoxia survival.

In a population of Japanese quail, a genetic selection was performed leading to two strains--one resistant and one susceptible to an acute hypoxic nitrogen challenge as well as to an acute carbon monoxide intoxication. Crossing these two strains gives an F1 hybrid whose survival to acute hypoxia appears to be very close to the susceptible strain. The difference in acute hypoxic survival already appears in embryos at the age of 12 d.

[Histogenetic study and mixed lymphocyte reaction in 2 lines of chickens homozygotic for haplotypes B14 and B19].

The histocompatibility status of homozygous chicken for B14 and B19 haplotypes of Hy-line stock origin was compared by skin grafts and the mixed lymphocyte reaction. No differences in graft survival (33 days) could be recorded in H-B compatible grafts in either haplotype tested. Reciprocal allografts however (B14 in equilibrium B19) were rejected within 12 days in both haplotypes.

Harmonic analysis of ultradian respiratory rhythms in four small laboratory vertebrates lit in LD12:12.

Fourier harmonic analysis has been applied to 20-min samples of VCO2, recorded every 12 sec over several (7-12) days, in one mouse, one rat, one guinea-pig, or one quail, maintained in controlled conditions of temperature, humidity and ventilation, and lit in LD12:12 (100 lux). The harmonic computations, during L and D of ultradian periods (1.2 hr less than tau less than 12 hr) evidence statistically significant differences in amplitude and phase between these four small laboratory species.

Inter and intraspecies genetic differences in survival to an acute carbon monoxide challenge in mice, rats, guinea-pigs, quails and chickens.

1. Groups of small laboratory vertebrates, of both sexes, have been submitted to an acute carbon monoxide challenge, close to a LD50. 2.

[Ultradian (between 5 and 70 minutes) respiratory (VO2, VCO2) rhythms of 4 small vertebrates used in biomedical research].

Four laboratory Vertebrate species with a predominant activity, either diurnal (Coturnix coturnix japonica), nocturnal (Rattus norvegicus, Mus musculus), or equivocal (Cavia porcellus), present, in usual housing conditions (temperature 20 degrees C, hygrometry 60-70%, acoustical background 70 dB, LD12:12 lighting L = 150 lx), food and water ad libitum, ultradian respiratory (VO2, VCO2) rhythms of short periods. The frequencies of these rhythms are independent of food intake and activity variations correlated to the lighting phase and regimen (LD, LL). The period (tau) of these ultradian respiratory rhythms is in isolated animals, between 5 and 70 min.