Impact of different earthworm ecotypes on water stable aggregates and soil water holding capacity

We carried out mesocosm experiments using either the anecic earthworm Lumbricus terrestris or the endogeic earthworm Allolobophora chlorotica and loam, silt loam and sandy loam soils to investigate the differing impact of these ecotypes on aggregate formation (percentage water stable aggregates, %WSA) and soil water holding capacity (WHC), two soil properties that underpin many of the ecosystem services provided by soils. Earthworms significantly increased %WSA (by 16-56 % and 19-63 % relative to earthworm free controls for L. terrestris and A. chlorotica, respectively). For L. terrestris this increase was significantly greater in the upper 6.5 cm of the soil where their casts were more obviously present. A. chlorotica treatments significantly increased WHC by 7-16 %. L. terrestris only caused a significant increase in WHC (of 11 %) in the upper 6.5 cm of the sandy loam soil. Linear regression indicated a consistent relationship between increases in %WSA and WHC for both earthworm species. However, for a given %WSA, WHC was higher for A. chlorotica than L. terrestris likely due to the known differences in their burrow structure. Overall, earthworms increased soil %WSA and WHC but the significant species / ecotype differences need to be considered in discussions of the beneficial impacts of earthworms to soil properties

Soil hydraulic function: Earthworm-plant root interactions

Relatively little is known about life in the soil, particularly the interactions between its components (such as plant roots, macrofauna and micro-organisms). Many of these interactions drive soil processes that give rise to ecosystem services supporting human wellbeing. Most of the valuable ecosystem services are driven by soil organisms, and earthworms are the key representatives. Earthworm activity underpins a number of soil properties that directly influence soil hydrological functioning and food production. However, the influence of different earthworm ecotypes and plant roots they interact with is largely unknown. This research project examines these effects through laboratory and field experiments. The data show that the interaction between earthworms and plant roots can significantly increase soil physico-hydraulic properties. However, laboratory experiments indicated that there are species / ecotype effects. The vertical burrowing earthworm Lumbricus terrestris increased soil water flow, but in conditions where their burrows are not connected to drainage systems, plant roots had a greater effect. The lateral burrowing earthworm Allolobophora chlorotica had a greater impact on soil hydraulic properties than L. terrestris. The presence of A. chlorotica in soils resulted in the greatest and most rapid increase in soil water flow through macropores > 3 mm diameter as a result of their interaction with plant roots. In the field experiment, the conversion of arable soil to ley caused a significant improvement to soil properties; the presence of earthworms in the ley was responsible for a significant proportion of these improvements. However, the magnitude of earthworm impacts is significantly controlled by seasonal climate variations. Furthermore, the presence of earthworms significantly increased plant biomass. These results show that the interaction between earthworms and plant roots can lead to increased soil drainage and also soil water retention which could help mitigate the impacts of increasing extreme weather events such as floods and droughts, thereby helping to maintain ecosystem services that are derived from soils

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19–free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19–free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19–free surgical pathways. Patients who underwent surgery within COVID-19–free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19–free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score–matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19–free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19–free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Effects of winter wheat and endogeic earthworms on soil physical and hydraulic properties

Earthworms directly and indirectly affect soil physico-hydraulic properties. We studied interactions between winter wheat and the common European earthworm Allolobophora chlorotica, testing for impacts upon soil physico-hydraulic properties. Column experiments with three different soil textures and field-relevant earthworm densities were conducted. Saturated hydraulic conductivity (Ks) increased over time in earthworm treatments, with the increase occurring most rapidly in the plant plus earthworm treatment. After 16 weeks Ks had increased in the treatment comprising both plants and earthworms by factors of 12, 34 and 39 in the loam, silt-loam and sandy-loam soils respectively relative to controls. The presence of earthworms resulted in an 88.5% increase in the contribution of pores >3 mm diameter to water flow. In the majority of treatments, soil water-holding capacity and percentage water-stable aggregates of the 5 cm topsoil in both the plant and the earthworm treatments increased significantly compared to controls with the plant plus earthworm treatment showing the greatest increase. Plant growth was greater in the presence than absence of earthworms. Our study shows synergistic and additive effects on soil physical properties in the presence of both earthworms and plants compared to when only earthworms or plants are present. It shows that it is not just vertical-burrowing anecic earthworms that can have a significant effect on soil hydraulic properties but that field-relevant densities of endogeic earthworms such as A. chlorotica can also contribute to soil water flow regulation

Utilisation de la petite irrigation à basse pression dans les zones montagneuses du Maroc

In order to improve the use efficiency of available water and increase its productivity at small farm scale in mountainous areas, we have undertaken experimental irrigation trials for some vegetable crops and olive trees using low pressure drip irrigation in TiziN'Test (Taroudant) and Tagnza (Amsekroud) areas. Demonstration plots have been installed and equipped with a low-pressure small-scale irrigation kit consisting of a tank raised 2 m above the plot level. The water tank was connected to irrigation ramps equipped with drippers. Through the gravity effect, the water goes out the orifices of the low-flow drippers to reach the plants roots’ zones. This irrigation system allowedsaving 47% of irrigation water compared to gravity irrigation (in a basin for fruit trees), a significant time and labor saving and a net improvement in the productivity around 51%. Based on this method, each plant receives the quantity of water corresponding to its estimated requirements, when reducing runoff and evaporation. Such method allows also avoiding leaf wetting, which causes leaf diseases, particularly powdery mildew. We should note that the local populations actively participated in the implementation of these experiments. Such participation could help to this low cost technology transfer.Dans le but d’améliorer l’efficience d’utilisation de l’eau disponible et d’augmenter sa productivité au niveau des petites exploitations des zones montagneuses, nous avons entrepris des travaux expérimentaux d'irrigation des cultures maraîchères et de la culture de l’olivier irriguées par le système goutte à goutte à basse pression à Tizi N'Test (Taroudant) et à Tagnza (Amsekroud). En effet, des parcelles de démonstration ont été installées et équipées d'un kit de petite irrigation à basse pression composé d’une citerne surélevée de 2 m du niveau de la parcelle et reliée à des rampes d'irrigation équipées de goutteurs. Grâce à la force de pesanteur, l'eau quitte les orifices des goutteurs à faible débit pour atteindre les zones racinaires des plantes. Avec ce système, on a pu économiser 47%de l'eau d'irrigation par rapport à l'irrigation gravitaire, une économie du temps de travail et de main d’œuvre importante et une nette amélioration du rendement de l’ordre de 51% pour certaines cultures maraichères comme la pomme de terre. Ces goutteurs à basse pression ont permis à chaque plante de recevoir la quantité d'eau qui correspond approximativement à ses besoins tout en réduisant le ruissellement et l'évaporation directe et en évitant l'humectation du feuillage, qui provoque des maladies foliaires, notamment l'oïdium. Il faut noter que les populations de ces localités ont participé de manière active à la réalisation de ces essais. Cette participation contribuerait à la l’adoption et la diffusion de cette technique « à faible coût » à grandes échelles spatiales

Effets de la salinité sur l'absorption des nutriments, les paramètres biochimiques et la croissance du Bleu Panicum (Panicum antidotale Retz) et du Maïs d’ensilage (Zea mays L)

Saline-tolerant alternative crops develop complex mechanisms under biosaline conditions. We investigated the effect of saline water on nutrient uptake, physiological and biochemical parameters of Blue Panic (Panicum antidotale Retz) and silage maize (Zea mays L). Mesocosms were established in four replicates for each plant species in an orthogonal design with different levels of saline irrigation water as treatments giving T0 = 0.9 dS m-1 (tap water), T1 = 3 dS m -1, T2 = 6 dS m-1 and T3 = 10 dS m-1, for 8 weeks. Increasing salinity caused a depressive effect on silage maize's physiological parameters, leading to a significant decrease in growth (up to 37%), aboveground (up to 58%) and root (up to 87%) dry matter biomass compared to control. As well as a decrease of chlorophyll a (up to 71%), chlorophyll b (up to 77%) and carotenoid (up to 49%) compared to control. For blue panic, salinity did not, however, affect the studied physiological and biochemical parameters. Nitrogen, phosphorus, potassium and calcium uptake, of silage maize, decreased with increasing salinity levels to be significant in irrigation water with electrical conductivity ≥ 6 dS m-1 relative to control. The sodium content in different parts of silage maize (leaf, stem and root), on the other hand, increased significantly with increasing salinity. The accumulation of calcium, potassium and nitrogen increased slightly in the blue panic, but this was only significant in separate parts of the plant. Overall, our study indicates that silage maize is more sensitive to saline conditions (particularly ≥ 6 dS m-1) compared to blue panic which tolerates well high saline environment ≥ 10 dS m-1. Our results, suggest therefore that the introduction of blue panic as an alternative crop on salt affected soils, such as the irrigated perimeter of Foum El Oued in Laâyoune in Morocco, would exhibit high performance better than traditional crops as silage maize and therefore would improve the local farmers’ income.Les cultures alternatives tolérantes à la salinité développent des mécanismes complexes dans les conditions biosalines. Nous avons étudié l'effet de l'eau salée sur l'absorption des nutriments et les paramètres physiologiques et biochimiques du bleu panicum (Panicum antidotale Retz) et du maïs d’ensilage (Zea mays L). Des mésocosmes ont été établis en quatre répétitions pour chaque espèce de plante dans une conception orthogonale avec différents niveaux d'eau d'irrigation saline comme traitements donnant T0 = 0.9 dS.m-1 (eau du robinet), T1 = 3 dS m-1, T2 = 6 dS m-1 et T3 = 10 dS m-1, pendant 8 semaines. L'augmentation de la salinité a provoqué un effet dépressif sur le maïs d’ensilage, conduisant à une réduction significative de la croissance (jusqu'à 37%), de la biomasse aérienne sèche (jusqu'à 58%) et racinaire (jusqu'à 87%) par rapport au témoin. Ainsi qu'une diminution de la chlorophylle a (jusqu'à 71 %), de la chlorophylle b (jusqu'à 77 %) et des caroténoïdes (jusqu'à 49 %) par rapport au témoin. Pour le bleu panicum, la salinité n'a par contre pas affecté les paramètres physiologiques et biochimiques étudiés. L'absorption de l’azote, du phosphore, du potassium et du calcium, du maïs d’ensilage a diminué avec l'augmentation des niveaux de salinité pour être significative pour une eau d'irrigation avec une conductivité électrique ≥ 6 dS m-1 par rapport au contrôle. La teneur en sodium dans les différentes parties du maïs d’ensilage (feuille, tige et racine), par contre, a augmenté significativement avec l'augmentation de la salinité. L'accumulation du calcium, du potassium et de l’azote a légèrement augmenté chez le bleu panicum, mais n’était significatif que dans des parties distinctes de la plante. Dans l'ensemble, notre étude indique que le maïs est plus sensible aux conditions salines (notamment celles ≥ 6 dS m-1) par rapport au bleu panicum qui tolère bien un environnement de salinité élevé ≥ 10 dS.m-1. Nos résultats suggèrent ainsi que l'introduction du bleu panicum comme culture alternative sur les sols affectés par la salinité, comme le périmètre irrigué de Foum El Oued à Laâyoune au Maroc, résulterait en des rendements élevés meilleurs que les rendements des cultures traditionnelles comme le maïs d’ensilage et améliorerait donc le revenu des agriculteurs locaux