30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic – The GENEVA study

Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients

30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data

Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the Clavien–Dindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts

From sea monsters to charismatic megafauna: changes in perception and use of large marine animals

Marine megafauna has always elicited contrasting feelings. In the past, large marine animals were often depicted as fantastic mythological creatures and dangerous monsters, while also arousing human curiosity. Marine megafauna has been a valuable resource to exploit, leading to the collapse of populations and local extinctions. In addition, some species have been perceived as competitors of fishers for marine resources and were often actively culled. Since the 1970s, there has been a change in the perception and use of megafauna. The growth of marine tourism, increasingly oriented towards the observation of wildlife, has driven a shift from extractive to non-extractive use, supporting the conservation of at least some species of marine megafauna. In this paper, we review and compare the changes in the perception and use of three megafaunal groups, cetaceans, elasmobranchs and groupers, with a special focus on European cultures. We highlight the main drivers and the timing of these changes, compare different taxonomic groups and species, and highlight the implications for management and conservation. One of the main drivers of the shift in perception, shared by all the three groups of megafauna, has been a general increase in curiosity towards wildlife, stimulated inter alia by documentaries (from the early 1970s onwards), and also promoted by easy access to scuba diving. At the same time, environmental campaigns have been developed to raise public awareness regarding marine wildlife, especially cetaceans, a process greatly facilitated by the rise of Internet and the World Wide Web. Currently, all the three groups (cetaceans, elasmobranchs and groupers) may represent valuable resources for ecotourism. Strikingly, the economic value of live specimens may exceed their value for human consumption. A further change in perception involving all the three groups is related to a growing understanding and appreciation of their key ecological role. The shift from extractive to non-extractive use has the potential for promoting species conservation and local economic growth. However, the change in use may not benefit the original stakeholders (e.g. fishers or whalers) and there may therefore be a case for providing compensation for disadvantaged stakeholders. Moreover, it is increasingly clear that even non-extractive use may have a negative impact on marine megafauna, therefore regulations are needed.SFRH/BPD/102494/2014, UID/MAR/04292/2019, IS1403info:eu-repo/semantics/publishedVersio

Non-lethal assessment of reproductive characteristics for management and conservation of sharks

Chondrichthyans are one of the most vulnerable groups of marine species, with increasing numbers being listed as endangered or threatened. Fundamental to the conservation and management of any animal is an understanding of their reproduction and particularly, the size at which individuals enter the reproductive population. Size at maturity in sharks is typically obtained by macroscopic examination of the gonads after sacrificing the fish. Using the draughtboard shark Cephaloscyllium laticeps as a case study, we found that equivalent information can be obtained nondestructively using steroid hormone levels measured from a blood sample. This technique allowed us to release the shark after only 1 to 2 min of handling. A combination of plasma steroid hormone concentrations and an external measurement (total length for females and clasper length for males) was used to determine that over 90% of female and 95% of male sharks were either juveniles or adults. The estimates of size at maturity from the hormone analysis were within 3% of equivalent values of dissected sharks. Once validated, hormone levels can also be used to determine seasonal reproductive patterns for the adult population. Our results demonstrated how measurement of plasma levels of steroid hormones can provide a non-destructive method for obtaining reproductive data necessary for managing vulnerable and endangered shark species. The development of a non-destructive sampling tool also allows for improved ethical investigation into this vulnerable group of marine fishes

Endocrine and morphological correlates of reproduction in the draughtboard shark Cephaloscyllium laticeps (Elasmobranchii: Scyliorhinidae)

This study examined the endocrine and reproductive correlates of reproduction in 636 female and 468 male draughtboard sharks (Cephaloscyllium laticeps) captured from southeastern Australia. Females were oviparous and displayed a single external-type ovary with a maximum follicle diameter of 35mm. Vitellogenesis commenced at a follicle diameter of 10mm. Females showed a constant overlap between follicular recruitment, ovarian growth, and egg laying. The male reproductive tract consisted of paired testes with spermatocysts undergoing diametric\ud development. Plasma levels of the presumptive gonadal steroids, testosterone (T), 17b-estradiol (E2),\ud progesterone (P4), and 11-ketotestosterone (11-KT; males only) were correlated with morphological developmental stages of the gonads. In females, E2 increased as the follicle developed before declining as the follicle reached maturity. T remained low during the first stages of ovarian growth and increased as the follicle reached maturity. P4 showed a peak just before ovulation. In males, T was the only hormone that varied with maturity, increasing in adults; E2 and P4 were present at low plasma concentrations in males and did not change with stage of gonadal development. 11-KT was undetectable at all times. Endocrine changes in draughtboard sharks were consistent with\ud hormonal correlates reported for other species and suggest roles for E2 (in females) and T (in both sexes) in gametogenesis and P4 in maturational events in females

Embryonic diapause in the elasmobranchs

Embryonic diapause is a temporary suspension of development at any stage of embryogenesis, which prolongs the gestation period, allowing parturition to occur in conditions that are more suitable for newborns. This reproductive trait is widespread among all vertebrates, including elasmobranchs. Although it has only been confirmed in two elasmobranchs (Rhizoprionodon taylori and Dasyatis say), evidence indicates that at least 14 species of rays and two sharks undergo diapause, suggesting that this form of reproduction exists within a wide range of elasmobranch reproductive modes, including lecithotrophs and matrotrophs. Where it has been studied, embryogenesis is arrested at the blastodisc stage and preserved in the uterus for periods from four to 10 months. There are still many questions that remain unanswered concerning the knowledge on the biology of most diapausing species but it is clear that species benefit differently from this reproductive trait. As in other vertebrates, it is likely that environmental cues and hormones (especially progesterone and prolactin) are involved in the control of diapause in elasmobranchs, however rigorous testing of current hypothesis remains to be carried out. © 2012 Springer Science+Business Media B.V

Reproductive seasonality and embryo development in the draughtboard shark Cephaloscyllium laticeps

The draughtboard shark Cephaloscyllium laticeps is a common oviparous catshark found in Australia. Studies on the reproductive seasonality of catsharks and the reproductive endocrinology of oviparous elasmobranchs are limited to a few species. The aim of the present study was to investigate the reproductive seasonality and embryo development of C. laticeps using morphological and endocrine parameters. Macroscopic examinations of the reproductive system and embryo stages were recorded. The steroid hormones 17β- oestradiol (E2) and progesterone (P4) were measured in females, and testosterone (T) in both sexes. Females laid eggs throughout the year, but with a peak in egg deposition between January and June. Female T levels were higher in the middle of the year. Elevated P4 values coincided with the period of egg deposition, whereas E2 was depressed in the middle of the egg deposition stage. Females laid eggs in the absence of males for 15 months, and eggs were laid in pairs at monthly intervals. Hatching occurred after 12 months. Variability in gonadosomatic index, percentage of sperm in seminal vesicles, and plasma T levels for males indicated that males were reproductively active throughout the year.</jats:p

Reproductive seasonality and embryo development in the draughtboard shark Cephaloscyllium laticeps

The draughtboard shark Cephaloscyllium laticeps is a common oviparous catshark found in Australia. Studies on the reproductive seasonality of catsharks and the reproductive endocrinology of oviparous elasmobranchs are limited to a few species. The aim of the present study was to investigate the reproductive seasonality and embryo development of C. laticeps using morphological and endocrine parameters. Macroscopic examinations of the reproductive system and embryo stages were recorded. The steroid hormones 17β- oestradiol (E2) and progesterone (P4) were measured in females, and testosterone (T) in both sexes. Females laid eggs throughout the year, but with a peak in egg deposition between January and June. Female T levels were higher in the middle of the year. Elevated P4 values coincided with the period of egg deposition, whereas E2 was depressed in the middle of the egg deposition stage. Females laid eggs in the absence of males for 15 months, and eggs were laid in pairs at monthly intervals. Hatching occurred after 12 months. Variability in gonadosomatic index, percentage of sperm in seminal vesicles, and plasma T levels for males indicated that males were reproductively active throughout the year

Optimization of laminated composite plates and shells using genetic algorithms, neural networks and finite elements

Structural optimization using computational tools has become a major research field in recent years. Methods commonly used in structural analysis and optimization may demand considerable computational cost, depending on the problem complexity. Therefore, many techniques have been evaluated in order to diminish such impact. Among these various techniques, Artificial Neural Networks (ANN) may be considered as one of the main alternatives, when combined with classic analysis and optimization methods, to reduce the computational effort without affecting the final solution quality. Use of laminated composite structures has been continuously growing in the last decades due to the excellent mechanical properties and low weight characterizing these materials. Taken into account the increasing scientific effort in the different topics of this area, the aim of the present work is the formulation and implementation of a computational code to optimize manufactured complex laminated structures with a relatively low computational cost by combining the Finite Element Method (FEM) for structural analysis, Genetic Algorithms (GA) for structural optimization and ANN to approximate the finite element solutions. The modules for linear and geometrically non-linear static finite element analysis and for optimize laminated composite plates and shells, using GA, were previously implemented. Here, the finite element module is extended to analyze dynamic responses to solve optimization problems based in frequencies and modal criteria, and a perceptron ANN module is added to approximate finite element analyses. Several examples are presented to show the effectiveness of ANN to approximate solutions obtained using the FEM and to reduce significatively the computational cost