Prevalence of SARS-Cov-2 antibodies and living conditions: the French national random population-based EPICOV cohort

Background We aimed to estimate the seroprevalence of SARS-CoV-2 infection in France and to identify the populations most exposed during the first epidemic wave. Methods Random selection of individuals aged 15 years or over, from the national tax register (96% coverage). Socio-economic data, migration history, and living conditions were collected via self-computer-assisted-web or computer-assisted-telephone interviews. Home self-sampling was performed for a random subsample, to detect IgG antibodies against spike protein (Euroimmun), and neutralizing antibodies with in-house assays, in dried blood spots (DBS). Results The questionnaire was completed by 134,391 participants from May 2nd to June 2st, 2020, including 17,441 eligible for DBS 12,114 of whom were tested. ELISA-S seroprevalence was 4.5% [95% CI 3.9–5.0] overall, reaching up to 10% in the two most affected areas. High-density residences, larger household size, having reported a suspected COVID-19 case in the household, working in healthcare, being of intermediate age and non-daily tobacco smoking were independently associated with seropositivity, whereas living with children or adolescents did not remain associated after adjustment for household size. Adjustment for both residential density and household size accounted for much of the higher seroprevalence in immigrants born outside Europe, twice that in French natives in univariate analysis. Conclusion The EPICOV cohort is one of the largest national representative population-based seroprevalence surveys for COVID-19. It shows the major role of contextual living conditions in the initial spread of COVID-19 in France, during which the availability of masks and virological tests was limited.

Timber Losses during Harvesting in Managed Shorea robusta Forests of Nepal

Logging and sawing of timber using conventional tools by unskilled workers causes enormous damage to the valuable timber, residual stand, regeneration, and forest soil in Nepal. The purpose of this study was to find out the volume reduction factor and identify major strategies to reduce timber losses in the tree harvesting process in the Terai Shorea robusta forest of Nepal. Field measurements and product flow analysis of 51 felled trees from felling coupes and randomly selected 167 sawed logs were examined to study harvesting losses. Responses from 116 forest experts were analyzed to explore strategies for reducing harvesting and processing losses. The results showed that timber losses in the felling and bucking stage with and without stem rot were 23% and 22%, respectively. Similarly, timber losses in the sawing stage with and without stem rot were 31% and 30%, respectively. Paired t-test at 5% level of significance revealed that there was significant loss in both tree felling and log sawing stages with present harvesting practice. The most leading factor contributing to timber loss in all of the three stages was the use of inappropriate equipment during tree harvesting. Use of synthetic ropes for directional felling and skidding as well as flexible and portable sawing machine with size adjustment options during sawing were mainly recommended as strategies to reduce timber losses. This study serves as a baseline study to identify and quantify timber losses in different stages of tree conversion and also formulate their reduction strategies in Nepal.

A Novel Mri-Method Allows a Rapid and Robust Assessment of Muscle Quantity and Quality in Hemodialysis Patients.

BackgroundSarcopenia is a prevalent condition in patients on maintenance hemodialysis and associates with mortality. Research using magnetic resonance imaging (MRI) has demonstrated the importance of a proper body size-adjustment in the assessment of muscle mass, and that a muscle composition assessment including measurements of both muscle volume and fat infiltration improves the prediction of comorbidity and survival related to sarcopenia. Such combined muscle composition assessment has not previously been performed in hemodialysis patients.MethodsEleven hemodialysis patients were scanned using whole-body fat and water separated MRI and followed regarding survival and comorbidity for five years. Muscle composition was assessed using AMRA® Researcher. Using data from 9615 UK Biobank participants, sex and BMI-matched muscle volume z-scores and sex-adjusted muscle fat infiltration values were calculated for each patient. These measurements were then used for the calculation of a combined muscle score. Resulting three muscle measurements were associated with survival and comorbidity index.ResultsSix patients exhibited low muscle volume (muscle volume z-score <25th percentile (population wide)), and six patients presented with high muscle fat infiltration (>75th percentile (population wide)). During a 68-months follow-up, five patients died, four were transplanted and two remained on hemodialysis treatment. The combined muscle score was significantly associated with comorbidity index (p<0.05) and was highly predictive of survival (AUROC 0.97).ConclusionsThe combined assessment including both body size-adjusted muscle volume and muscle fat infiltration can be used to analyze muscle composition in hemodialysis patients. MRI based muscle composition assessment reflected comorbidity and predicted survival in hemodialysis patients.

Pituitary and ovarian hormones: is their plasma concentration affected by litter size in primiparous lactating rabbit does?

Genetic selection in commercial rabbit lines based on litter size has positively improved the number of kits suckling, presumably to weaning. Although it has been proven that the energetic balance of primiparous does is due to the need to satisfy pregnancy, lactation and growth requirements, litter size adjustment from 7 to 12 kits is applied as a routine in commercial rabbit farms. The suckling stimulus provokes a prolactin (PRL) secretion, which in turn can modulate the preovulatory release of luteinising hormone (LH) and, consequently, the ovulatory and productive responses of the does. This study aimed to determine if litter size of prolific primiparous rabbit does during lactation [Group HL, with high litter density (10-12 kits; n=21) and Group LL, with low litter density (7-9 kits; n=29)] influences plasma concentration of PRL. Blood samples from lactating does were taken weekly throughout lactation starting on day 4 post-partum, until day 32 post-partum, before and immediately after suckling. In addition, the does were re-inseminated after weaning (day 32 post-partum), and sampled at 0 and 60 min after induction of ovulation to determine whether litter size affected the peak of LH, progesterone (P4) concentrations and the main productive parameters of their second pregnancy. All hormones were determined by enzyme immunoassay. Statistical analysis of the results revealed that the PRL concentrations of hyperprolific rabbit does before and immediately after a suckling stimulus from 7-9 or 10-12 kits were significanltly different, as we only detected basal levels, with a rise after weaning in both groups. More studies are necessary, delaying blood sampling to later periods of time after the suckling stimulus, in order to conclude whether the peak release of this hormone is altered or not. There were also no differences in plasma LH and progesterone levels after artificial insemination, or in productive performance of these females after their second pregnancy. In conclusion, the litter size adjustment of prolific primiparous rabbits with 7 to 12 kits determines adequate pituitary, ovarian and reproductive responses at second parturition if the does are inseminated after weaning.

Organisational and relational factors that influence return to work and job retention: The contribution of activity ergonomics

BACKGROUND: Work is a determinant of employee health, and the same conditions that contribute to an illness do not favour return to work; consequently, they hinder job retention, other employees can become ill and new leaves are generated. OBJECTIVE: To analyse the nursing technicians work in intensive and semi-intensive care units (ICUs and SICUs) and discussed the influence of organisational and relational factors on return to work and job retention. This study also discusses the contributions of activity ergonomics to these processes. METHOD: Qualitative case study based on ergonomic work analysis (EWA). Data were collected using documentary analyses, and global, systematic, and participant observations involving nursing technicians working in ICUs and SICUs. RESULTS: Task planning and the staff size adjustment to respond to the work demands of these units were ineffective in real-world situations and were aggravated by cases of absenteeism, medical leave, and employees returning to work. CONCLUSIONS: Work structure limits return to work and job retention. An EWA based on the activities developed by professionals is a valid tool for understanding working processes by applying transforming actions to real-world work situations.

Size-adjustment techniques of lumbar spine dual energy X-ray absorptiometry measurements in assessing bone mineralization in children on maintenance hemodialysis

Objectives Growing skeleton is uniquely vulnerable to impaired mineralization in chronic kidney disease (CKD). Continued debate exists about the optimal method to adjust for body size when interpreting dual energy X-ray absorptiometry (DXA) scans in children with CKD given the burden of poor growth. The study aimed to evaluate the clinical usefulness of size-adjustment techniques of lumber-spine DXA measurements in assessing bone mineralization in children with kidney failure on maintenance hemodialysis (HD). Methods Case-control study included 93 children on maintenance HD (9–18 years; 48 males). Participants were subjected to spinal-DXA-scan to obtain areal bone mineral density (aBMD; g/cm2). Volumetric-BMD (vBMD; g/cm3) was mathematically estimated. Z-scores of aBMD for chronological age (aBMDZ-CA), aBMD adjusted for height age (aBMDZ-HA), and vBMDZ-score were calculated using mean and SD values of age subgroups of 442 healthy controls (7–18 years). Results In short-for-age CKD patients, aBMDZ-CA was significantly lower than vBMDZ-score, while aBMDZ-HA was significantly higher than aBMDZ-CA and vBMDZ-score. In normal height-for-age CKD patients, no significant difference between aBMDZ-scores and vBMDZ-score was detected. aBMDZ-CA was significantly lower and aBMDZ-HA was significantly higher in short-for-age compared to normal height-for-age patients without significant differences in vBMDZ-score. We observed age-related decrements in the percentage of HD patients with normal densitometric Z-scores, the effect of age was less pronounced in aBMDZ-HA than vBMDZ-score. vBMDZ-score correlated negatively with age, but not with heightZ-score. Conclusions Estimated vBMD seems to be a convenient size-adjustment approach of spinal-DXA measurements in assessing BMD especially in older short-for-age children with CKD. aBMDZ-CA underestimates, while aBMDZ-HA overestimates BMD in such patients.

Managing Cashew Rootstock Grafting Size Through Organic Fertilizers

Seed born cashew (Anacardium occidentale L) seedlings are planted directly when they are produced from polyclonal orchards. In a common scenario, cashew seedlings are grafted before transplanting. For this purpose, adjusting the size between scions and rootstock is highly important for the success of grafts and it can be achieved through a visual selection of scions. However, when working with large numbers of seedlings physical and visual selection becomes laborious and time consuming for the workers. Therefore, creating uniformity in seedlings size before grafting is crucial. We present experimental results showing the linear regression between the fertilization level and seedling stem size. Two experiments were conducted in Mozambique: One at Nassuruma cashew Research Station, Nampula province, following a Completely Randonmized Block Design (CRBD), seven treatments, ten bags per treatment and five replicates. The treatments consisted of a fertilizer organically composted from cashew nut shells and applied at rates of 0, 4, 8, 16, 32, 40 and 48% of the total amount of soil in each bag. The second experiment was carried out at Chizavane nursery, in Gaza Province, also based on CRBD, in factorial arrangement of 4 and 3 levels of Kelp and Stimu biofertilizers respectively. Two stem size variables, diameter and height, were considered and data collected at 120 days after seedlings emergence in Nampula and 45 days after emergence in Gaza Province. Polynomial or simple regression analysis model for stem diameter and plant height was performed. The stem diameter was linearly described as an increasing equation. The height was also linearly related to fertilizer but following a decreased equation. We concluded that applying appropriate dosage of fertilizer in the soil or on the leaves could adjust the stem size of the rootstock required for grafting and therefore adjust the stem to the size of scions available. The treatments with high level of Kelp, Stimu and cashew compost fertilization resulted in increase of 8,5%, 6% and 16,6% of diameter respectively. However, the treatments caused a reduction of height at rate of 14,3%, 3,2% and 25,08% respectively. The stem and scion size adjustment are highly important for increasing the grafting success rate in a cashew nursery.