A longer wood growing season does not lead to higher carbon sequestration.

A reliable assessment of forest carbon sequestration depends on our understanding of wood ecophysiology. Within a forest, trees exhibit different timings and rates of growth during wood formation. However, their relationships with wood anatomical traits remain partially unresolved. This study evaluated the intra-annual individual variability in growth traits in balsam fir [Abies balsamea (L.) Mill.]. We collected wood microcores weekly from April to October 2018 from 27 individuals in Quebec (Canada) and prepared anatomical sections to assess wood formation dynamics and their relationships with the anatomical traits of the wood cells. Xylem developed in a time window ranging from 44 to 118 days, producing between 8 and 79 cells. Trees with larger cell production experienced a longer growing season, with an earlier onset and later ending of wood formation. On average, each additional xylem cell lengthened the growing season by 1 day. Earlywood production explained 95% of the variability in xylem production. More productive individuals generated a higher proportion of earlywood and cells with larger sizes. Trees with a longer growing season produced more cells but not more biomass in the wood. Lengthening the growing season driven by climate change may not lead to enhanced carbon sequestration from wood production.

The early bud gets the cold: Diverging spring phenology drives exposure to late frost in a Picea mariana [(Mill.) BSP] common garden.

Under climate change, the increasing occurrence of late frost combined with advancing spring phenology can increase the risk of frost damage in trees. In this study, we tested the link between intra-specific variability in bud phenology and frost exposure and damages. We analysed the effects of the 2021 late frost event in a black spruce (Picea mariana (Mill.) BSP) common garden in Québec, Canada. We hypothesised that the timing of budbreak drives the exposure of vulnerable tissues and explains differences in frost damage. Budbreak was monitored from 2015 to 2021 in 371 trees from five provenances originating between 48° and 53° N and planted in a common garden at 48° N. Frost damages were assessed on the same trees through the proportion of damaged buds per tree and related to the phenological phases by ordinal regressions. After an unusually warm spring, minimum temperatures fell to -1.9°C on May 28 and 29, 2021. At this moment, trees from the northern provenances were more advanced in their phenology and showed more frost damage. Provenances with earlier budbreak had a higher probability of damage occurrence according to ordinal regression. Our study highlights the importance of intra-specific variability of phenological traits on the risk of frost exposure. We provide evidence that the timings of bud phenology affect sensitivity to frost, leading to damages at temperatures of -1.9°C. Under the same conditions, the earlier growth reactivation observed in the northern provenances increases the risks of late frost damage on the developing buds.

Upscaling xylem phenology: sample size matters.

BACKGROUND AND AIMS: Upscaling carbon allocation requires knowledge of the variability at the scales at which data are collected and applied. Trees exhibit different growth rates and timings of wood formation. However, the factors explaining these differences remain undetermined, making samplings and estimations of the growth dynamics a complicated task, habitually based on technical rather than statistical reasons. This study explored the variability in xylem phenology among 159 balsam firs [Abies balsamea (L.) Mill.]. METHODS: Wood microcores were collected weekly from April to October 2018 in a natural stand in Quebec, Canada, to detect cambial activity and wood formation timings. We tested spatial autocorrelation, tree size and cell production rates as explanatory variables of xylem phenology. We assessed sample size and margin of error for wood phenology assessment at different confidence levels. KEY RESULTS: Xylem formation lasted between 40 and 110 d, producing between 12 and 93 cells. No effect of spatial proximity or size of individuals was detected on the timings of xylem phenology. Trees with larger cell production rates showed a longer growing season, starting xylem differentiation earlier and ending later. A sample size of 23 trees produced estimates of xylem phenology at a confidence level of 95 % with a margin of error of 1 week. CONCLUSIONS: This study highlighted the high variability in the timings of wood formation among trees within an area of 1 km2. The correlation between the number of new xylem cells and the growing season length suggests a close connection between the processes of wood formation and carbon sequestration. However, the causes of the observed differences in xylem phenology remain partially unresolved. We point out the need to carefully consider sample size when assessing xylem phenology to explore the reasons underlying this variability and to allow reliable upscaling of carbon allocation in forests.

Trend of emergency general surgery procedures during COVID-19 pandemic.

BACKGROUND: In early 2020, the novel coronavirus infection (COVID-19) spread rapidly throughout the whole world, causing a massive response in terms of health resource disposal. Moreover, lockdowns were imposed in entire countries. This study aims to assess whether there was a downward trend in emergency general surgery (EGS) procedures accomplished throughout the COVID-19 pandemic and to determine patients' and diseases' characteristics. METHODS: This is a multicentric retrospective observational cohort analysis conducted on patients who underwent EGS procedures during the lockdown and the same period of the previous year in the three Third Level Hospitals of Friuli Venezia Giulia, Italy. RESULTS: During the study period, 138 patients underwent EGS procedures versus the 197 patients operated on in 2019, meaning a 30.0% decrease in the number of surgeries performed. The incidence rate for EGS procedures was 2.5 surgeries per day during the COVID-19 pandemic compared to 3.5 surgeries per day in 2019 (P<0.001). The characteristics of patients operated on in 2020 were comparable to those of patients who underwent EGS in 2019, except for the higher prevalence of male patients during the COVID-19 pandemic (76.8 vs. 55.8; P<0.001). No difference was recorded in disease severity between the two study periods. CONCLUSIONS: During the COVID-19 pandemic, a significant reduction in EGS procedures carried out was recorded. However, no clear explanation can be given to elucidate this fact.

Clinical outcomes and quality of life associated with the use of a biosynthetic mesh for complex ventral hernia repair: analysis of the "Italian Hernia Club" registry.

With the development of newer meshes and approaches to hernia repair, it is currently difficult to evaluate their performances while considering the patients' perspective. The aim of the study was to assess the clinical outcomes and quality of life consequences of abdominal hernia repairs performed in Italy using Phasix and Phasix ST meshes through the analysis of real-world data to support the choice of new generation biosynthetic meshes. An observational, prospective, multicentre study was conducted in 10 Italian clinical centres from May 2015 to February 2018 and in 15 Italian clinical centres from March 2018 to May 2019. The evaluation focused on patients with VHWG grade II-III who underwent primary ventral hernia repair or incisional hernia intervention with a follow-up of at least 18 months. Primary endpoints included complications' rates, and secondary outcomes focused on patient quality of life as measured by the EuroQol questionnaire. Seventy-five patients were analysed. The main complications were: 1.3% infected mesh removal, 4.0% superficial infection requiring procedural intervention, 0% deep/organ infection, 8.0% recurrence, 5.3% reintervention, and 6.7% drained seroma. The mean quality of life utility values ranged from 0.768 (baseline) to 0.967 (36 months). To date, Phasix meshes have proven to be suitable prostheses in preventing recurrence, with promising outcomes in terms of early and late complications and in improving patient quality of life.

Minimum spring temperatures at the provenance origin drive leaf phenology in sugar maple populations.

Late frost can cause damage to trees, especially to the developing bud of broadleaf species in spring. Through long-term adaptation, plants adjust leaf phenology to achieve an optimal trade-off between growing season length and frost avoidance. In this study, we aim to assess ecotypic differentiation in leaf development of sugar maple populations planted in a common garden. A total of 272 sugar maple seedlings from 29 Canadian provenances were planted at the northern boundary of the natural range, and the phenological phases of bud and leaf development were monitored during spring 2019. The wide geographical area under evaluation showed a complex seasonal pattern of temperature, with spring warming occurring later in the north and close to the sea. Overall, leaf development lasted between 20 and 36 days, from the end of May to end of June. We observed different timings and rates of leaf development among provenances, demonstrating the occurrence of ecotypes in this species. Minimum April temperatures of the original sites were able to explain such differences, while maximum April temperatures were not significant. Seedlings from sites with colder minimum April temperatures completed leaf development earlier and faster. On average, leaf development diverged by up to 6 days among provenances, with minimum April temperatures ranging from -3 to 3 °C. Our results demonstrated that the avoidance of late spring frost is a driving force of leaf development in sugar maple populations. In the colder sites, the growing season is a limiting factor for tree growth. Thus, when thermal conditions become favorable in spring, an earlier growth reactivation and high metabolic activity ensure a fast leaf emission, which maximizes the period available for photosynthesis and growth. These patterns demonstrate the long-term phenological adaptation of sugar maple populations to local climatic conditions and suggest the importance of frost events for leaf development.

Budget Impact Analysis of a Biosynthetic Mesh for Incisional Hernia Repair.

PURPOSE: With the development of newer prostheses for hernia repair, it is nowadays difficult to understand the total cost of managing patients treated with these advanced medical devices, especially in the complex abdomen, in which various complications may occur. The aim of this study was to determine the economic implications of these prostheses in order to inform decision making in the management of incisional hernia repair. METHODS: A budget impact analysis model was developed to evaluate the economic consequences related to the management of patients undergoing complex (Centers for Disease Control and Prevention wound class II-III or Ventral Hernia Working Group grade 2/3) incisional hernia repair through biosynthetic, synthetic, or biological meshes, from the hospital perspective in Italy. The model was populated with complication rates mainly retrieved from the literature to compare the current scenario with 60%, 10%, and 30% rates of synthetic, biosynthetic, and biological mesh utilization, respectively, with future hypothetical scenarios that consider increasing rates of biosynthetic mesh utilization with respect to the other types of mesh in the next 5 years. Hospital costs of the different events were estimated based on health care resource consumption derived from an electronic survey addressed to key opinion leaders in the field. FINDINGS: The analysis compared the current scenario with future hypothetical scenarios that consider increasing utilization rates of biosynthetic meshes of 25%, 38%, and 44% in the next 1, 3, and 5 years, as estimated by clinicians. Considering 40,000 incisional hernia repairs per year, an increasing use of the biosynthetic meshes may result in a decrease in the total hospital budget of about €153 million in the next 5 years, with a savings per patient of about €770. IMPLICATIONS: The findings of this study support the use of biosynthetic meshes for complex abdominal wall repairs in Italy, showing a potential decrease in the hospital budget in Italy after the diffusion of the new biosynthetic prostheses. Further studies and data from clinical practice would provide additional information to increase the understanding of the economic sustainability of these advanced devices.