Metatranscriptomics sheds light on the links between the functional traits of fungal guilds and ecological processes in forest soil ecosystems.

Soil fungi belonging to different functional guilds, such as saprotrophs, pathogens, and mycorrhizal symbionts, play key roles in forest ecosystems. To date, no study has compared the actual gene expression of these guilds in different forest soils. We used metatranscriptomics to study the competition for organic resources by these fungal groups in boreal, temperate, and Mediterranean forest soils. Using a dedicated mRNA annotation pipeline combined with the JGI MycoCosm database, we compared the transcripts of these three fungal guilds, targeting enzymes involved in C- and N mobilization from plant and microbial cell walls. Genes encoding enzymes involved in the degradation of plant cell walls were expressed at a higher level in saprotrophic fungi than in ectomycorrhizal and pathogenic fungi. However, ectomycorrhizal and saprotrophic fungi showed similarly high expression levels of genes encoding enzymes involved in fungal cell wall degradation. Transcripts for N-related transporters were more highly expressed in ectomycorrhizal fungi than in other groups. We showed that ectomycorrhizal and saprotrophic fungi compete for N in soil organic matter, suggesting that their interactions could decelerate C cycling. Metatranscriptomics provides a unique tool to test controversial ecological hypotheses and to better understand the underlying ecological processes involved in soil functioning and carbon stabilization.

Environmental Health Threats to Latino Migrant Farmworkers.

Approximately 75% of farmworkers in the United States are Latino migrants, and about 50% of hired farmworkers do not have authorization to work in the United States. Farmworkers face numerous chemical, physical, and biological threats to their health. The adverse effects of these hazards may be amplified among Latino migrant farmworkers, who are concurrently exposed to various psychosocial stressors. Factors such as documentation status, potential lack of authorization to work in the United States, and language and cultural barriers may also prevent Latino migrants from accessing federal aid, legal assistance, and health programs. These environmental, occupational, and social hazards may further exacerbate existing health disparities among US Latinos. This population is also likely to be disproportionately impacted by emerging threats, including climate change and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Latino migrant farmworkers are essential to agriculture in the United States, and actions are needed to protect this vulnerable population.

Combined lung and liver procurement in controlled donation after circulatory death using normothermic abdominal perfusion. Initial experience in two Spanish centers.

Combining simultaneously lung and liver procurement in controlled donation after circulatory death (cDCD) using normothermic abdominal perfusion (NRP) for abdominal grafts and cooling and rapid recovery technique (RR) for the lungs increases the complexity of the procurement procedure and might injure the grafts. A total of 19 cDCDs from two centers using this combined procedure were evaluated, and 16 liver and 21 lung transplantations were performed. As controls, 34 donors after brain death (DBDs) were included (29 liver and 41 lung transplantations were performed). Two cDCD liver recipients developed primary nonfunction (12.5%). No cases of ischemic cholangiopathy were observed among cDCD recipients. The 1-year and 2-year liver recipients survival was 87.5% and 87.5% for the cDCD group, and 96% and 84.5% for the DBD group, respectively (P = .496). The 1-year and 2-year lung recipients survival was 84% and 84% for the cDCD group and 90% and 90% for the DBD group, respectively (P = .577). This is the largest experience ever reported in cDCD with the use of NRP combined with RR of the lungs. This combined method offers an outstanding recovery rate and liver and lung recipients survival comparable with those transplanted with DBDs. Further studies are needed to confirm our findings.

ENSO and NAO affect long-term leaf litter dynamics and stoichiometry of Scots pine and European beech mixedwoods.

Litterfall dynamics (production, seasonality and nutrient composition) are key factors influencing nutrient cycling. Leaf litter characteristics are modified by species composition, site conditions and water availability. However, significant evidence on how large-scale, global circulation patterns affect ecophysiological processes at tree and ecosystem level remains scarce due to the difficulty in separating the combined influence of different factors on local climate and tree phenology. To fill this gap, we studied links between leaf litter dynamics with climate and other forest processes, such as tree-ring width (TRW) and intrinsic water-use efficiency (iWUE) in two mixtures of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in the south-western Pyrenees. Temporal series (18 years) of litterfall production and elemental chemical composition were decomposed following the ensemble empirical mode decomposition method and relationships with local climate, large-scale climatic indices, TRW and Scots pine's iWUE were assessed. Temporal trends in N:P ratios indicated increasing P limitation of soil microbes, thus affecting nutrient availability, as the ecological succession from a pine-dominated to a beech-dominated forest took place. A significant influence of large-scale patterns on tree-level ecophysiology was explained through the impact of the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO) on water availability. Positive NAO and negative ENSO were related to dry conditions and, consequently, to early needle shedding and increased N:P ratio of both species. Autumn storm activity appears to be related to premature leaf abscission of European beech. Significant cascading effects from large-scale patterns on local weather influenced pine TRW and iWUE. These variables also responded to leaf stoichiometry fallen 3 years prior to tree-ring formation. Our results provide evidence of the cascading effect that variability in global climate circulation patterns can have on ecophysiological processes and stand dynamics in mixed forests.

A Model Analysis for the Design and Deployment of an Eulerian Sediment Trap Mooring Array in a Western Boundary Upwelling System from Southeast Brazil.

This work addresses the design and configuration of a Eulerian sediment trap mooring array, which was deployed at the shelf edge (zm ≈ 140 m) 80 km off Cabo Frio, SE- Brazil (23° S). The site was subject to interplay between the Tropical Waters (TW) of the Brazil Current (BC), intrusions from the South Atlantic Central Waters (SACW), which are the source of upwelling in the region, and other oceanographic processes. Detailed computations were used to optimize the total weight, buoyancy balance, and maximum acceptable tilt to avoid hydrodynamic bias in the trapping efficiency and array adaptation to the local oceanographic conditions with the assistance of Matlab and Muringa programs and Modular Ocean Model 4.0 (MOM; i.e., to assert the vertical distribution of the meridional current component). The velocity range of the current component was determined by short term measurements to be between 0.1 and 0.5 m/s. Projections led to a resulting minimum anchor weight of 456 kg. The necessary line tension was ascertained by using the appropriate distribution of a series of buoys along the array, which finally attained a high vertical load of 350 kg because of the attached oceanographic equipment. Additional flotation devices resulted in a stable mooring array as reflected by their low calculated tilt (2.6° ± 0.6°). A low drag of 16 N was computed for the maximum surface current velocity of 0.5 m/s. The Reynolds number values ranged from 4 × 104 to 2 × 105 and a cone-trap aspect ratio of 1.75 was used to assess the trap sampling efficiency upon exposure to different current velocities.

Comparison of abdominal adipose tissue versus body mass index (BMI) as a predictor of complications and survival in liver transplantation.

INTRODUCTION: Because of the obesity epidemic, more obese patients are on liver transplant (LT) waiting lists. The diseases associated with obesity may increase complications and limit survival after LT. However, there is no established measure or cut-off point to determine this impact and aid decision making. The aim of the present study is to evaluate obesity in patients undergoing LT via BMI and CT-based measurement of adipose tissue (AAT). These parameters will be used to predict the risk of postoperative complications and 5-year survival. METHODS: A retrospective, single-center study was carried out at a tertiary Spanish hospital, including all patients who received LT between January 2012 and July 2019 (n = 164). The patients were adults who underwent LT using the 'piggyback' technique, preserving the recipient vena cava. Visceral adipose tissue (VAT) and BMI were calculated to examine correlations with postoperative complications and 5-year survival. RESULTS: No significant association was found between postoperative complications by Comprehensive Complication Index, BMI, AAT/height, subcutaneous fat/height and VAT/height. Kaplan-Meier curves for 5-year survival compared LT recipients with BMI < 30.45 versus ≥30.45, with an estimated survival of 58.97 months versus 43.11 months, respectively (P < .001) (Fig. 3) and for LT recipients with an AAT/height <27.35 mm versus ≥27.35 mm, with an estimated survival of 57.69 months versus 46.34 months (P = .001). CONCLUSIONS: This study does not show a higher rate of postoperative complications in obese patients. There is a significantly lower long-term survival in patients with AAT/height ≥27.35 mm and BMI ≥ 30.45. BMI is a valid estimate of obesity and is predictive of survival.

Prevalence of SARS-CoV-2 infection and impact of the COVID-19 pandemic in avocado farmworkers from Mexico.

Introduction: The COVID-19 pandemic disproportionately affected farmworkers in the United States and Europe, leading to increased morbidity and mortality. However, little is known about the specific impact of the pandemic on agriculture and food production workers in low- and middle-income countries. This study aimed to investigate the prevalence of SARS-CoV-2 infection and assess the mental health and economic consequences of the COVID-19 pandemic among avocado farmworkers in Michoacan, Mexico. Methods: We conducted a cross-sectional study of adult farmworkers (n = 395) in May 2021. We collected survey data, nasal swabs and saliva samples for SARS-CoV-2 RNA detection, and blood samples for immunoglobulin G (IgG) reactivity measurements. Results: None of the farmworkers tested positive for SARS-CoV-2 RNA. However, among unvaccinated farmworkers (n = 336, 85%), approximately one-third (33%) showed evidence of past infection (positive for IgG against SARS-CoV-2). Unvaccinated farmworkers who lived with other farmworkers (aRR = 1.55; 95% CI: 1.05, 2.05), had ever lived with someone with COVID-19 (aRR = 1.82; 95% CI: 1.22, 2.43), and who had diabetes (aRR = 2.19; 95% CI: 1.53, 2.85) had a higher risk of testing IgG-positive for SARS-CoV-2 infection. In contrast, unvaccinated farmworkers living in more rural areas (outside of Tingambato or Uruapan) (aRR = 0.71; 95% CI: 0.46, 0.96) or cooking with wood-burning stove (aRR = 0.75; 95% CI: 0.55, 0.96) had a lower risk of IgG-positivity. Moreover, 66% of farmworkers reported a negative impact of the pandemic on their lives, 29% reported experiencing food insecurity and difficulty paying bills, and 10% reported depression or anxiety symptoms. Conclusion: The COVID-19 pandemic has significantly affected the mental health and financial well-being of avocado farmworkers. Consequently, the implementation of interventions and prevention efforts, such as providing mental health support and food assistance services, is imperative.

Colorectal liver metastasis in the setting of lymph node metastasis: defining the benefit of surgical resection.

BACKGROUND: For patients with colorectal liver metastasis (CLM), the presence of concomitant perihepatic/para-aortic lymph node metastasis (LNM) is considered a contraindication to liver resection. We sought to determine the benefits of liver resection among patients with CLM + LNM by examining long-term outcomes among a large cohort of patients. METHODS: Between October 1996 and December 2007, 61 patients with CLM and pathologically proven LNM were identified from an international multi-institutional database of 1629 patients. The effect of LNM, as well as other prognostic factors, on recurrence-free and overall survival was analyzed. RESULTS: Median overall survival was 32 months, and 1-, 3-, and 5-year overall survival were 86, 35, and 18%, respectively. Five patients were alive and disease-free at last follow-up. Survival was associated with location of LNM. Specifically, 5-year overall survival was 30% among patients with LNM along the hepatoduodenal ligament/retropancreatic area (area 1), 14% among patients with LNM along the common hepatic artery/celiac axis (area 2), and there was only one long-term survivor who experienced recurrent disease among patients who had CLM + para-aortic LNM (area 3) (P = 0.004). On multivariate analyses, overall margin status (hazard ratio [HR] = 2.0), treated number of metastases >6 (HR = 2.3) and para-aortic lymph node involvement (HR = 2.6) each remained significantly associated with increased risk of death (all P < 0.05). CONCLUSIONS: Although overall survival in the setting of LNM is only 18%, certain subsets of patients with LNM can benefit from surgical resection. Specifically, patients with CLM + LNM isolated to area 1 had a 5-year survival of approximately 30%, while long-term survival among patients with para-aortic LNM was rare.

Multiorgan retrieval and preservation of the thoracic and abdominal organs in Maastricht III donors.

This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.

Foundation of One-Particle Reduced Density Matrix Functional Theory for Excited States.

In Phys. Rev. Lett. 2021, 127, 023001 a reduced density matrix functional theory (RDMFT) was proposed for calculating energies of selected eigenstates of interacting many-Fermion systems. Here, we develop a solid foundation for this so-called w-RDMFT and present the details of various derivations. First, we explain how a generalization of the Ritz variational principle to ensemble states with fixed weights w in combination with the constrained search would lead to a universal functional of the one-particle reduced density matrix. To turn this into a viable functional theory, however, we also need to implement an exact convex relaxation. This general procedure includes Valone's pioneering work on ground state RDMFT as the special case w = (1,0, ···). Then, we work out in a comprehensive manner a methodology for deriving a compact description of the functional's domain. This leads to a hierarchy of generalized exclusion principle constraints which we illustrate in great detail. By anticipating their future pivotal role in functional theories and to keep our work self-contained, several required concepts from convex analysis are introduced and discussed.

Extreme Heat and COVID-19: A Dual Burden for Farmworkers.

Currently, there is an extensive literature examining heat impacts on labor productivity and health, as well as a recent surge in research around COVID-19. However, to our knowledge, no research to date examines the dual burden of COVID-19 and extreme heat on labor productivity and laborers' health and livelihoods. To close this research gap and shed light on a critical health and livelihood issue affecting a vulnerable population, we urge researchers to study the two topics in tandem. Because farmworkers have a high incidence of COVID-19 infections and a low rate of inoculation, they will be among those who suffer most from this dual burden. In this article, we discuss impacts from extreme heat and COVID-19 on farm laborers. We provide examples from the literature and a conceptual framework showing the bi-directional nature of heat impacts on COVID-19 and vice versa. We conclude with questions for further research and with specific policy recommendations to alleviate this dual burden. If implemented, these policies would enhance the wellbeing of farmworkers through improved unemployment benefits, updated regulations, and consistent implementation of outdoor labor regulations. Additionally, policies for farmworker-related health needs and cultural aspects of policy implementation and farmworker outreach are needed. These and related policies could potentially reduce the dual burden of COVID-19 and extreme heat impacts while future research explores their relative cost-effectiveness.

Antibody response to the messenger RNA-1273 vaccine (Moderna) in liver transplant recipients.

Different reports have shown the clinical and serologic response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in preventing coronavirus disease 2019 (COVID-19) in the general population, but few studies have examined these responses in transplant recipients. We assessed the vaccine immunogenicity of two doses (100 µg) of the mRNA-1273 vaccine (Moderna) administered with a 28-day interval in liver transplant recipients (LTRs) at follow-up at the Marques de Valdecilla University Hospital. LTRs without a history of COVID-19 infection were tested for SARS-CoV-2 immunoglobulin G (IgG) antibodies directed against the spike protein (S) a median of 43 days after receiving the second Moderna vaccine dose. Clinical data, including immunosuppressive regimen and routine laboratory data, were obtained from the medical record of each patient up to 3 months before the date of the first vaccination. Factors associated with serologic response were evaluated through logistic regression. In total, 129 LTRs who had anti-S results were included. Most patients were men (n = 99; 76.7%) with a median age of 63 years (interquartile range, 56-68). Alcohol (43.4%) and chronic hepatitis C (18.6%) were the most frequent causes of liver transplantation. A positive anti-S IgG response was observed in 113 LTRs (87.6%; 95% confidence interval [CI], 80.8-92.2). A strong inverse relationship between mycophenolate mofetil use and serologic response was found (odds ratio, 0.07; 95% CI, 0.02-0.26; p = 0.001). Conclusion: Most LTRs develop an immunological response to the Moderna SARS-CoV-2 mRNA-based vaccine. An immunosuppressive regimen that includes mycophenolate predicts a weak serologic response.

Liver resection for colorectal metastases in presence of extrahepatic disease: results from an international multi-institutional analysis.

BACKGROUND: Hepatic resection for colorectal liver metastasis (CLM) with concomitant extrahepatic disease (EHD) is a controversial topic. We sought to evaluate the long-term outcome of patients undergoing liver resection for CLM in presence of EHD and identify factors associated with prognosis. METHODS: From 1996 to 2007, a total of 1629 patients who underwent resection of CLM were identified from an international multi-institutional database. One hundred seventy-one patients (10.4%) underwent resection of EHD. Clinicopathologic and outcome data were collected and analyzed by univariate and multivariate analyses. RESULTS: Median number of treated CLM was 2 (range, 1-18); most patients had solitary EHD (n = 114; 66.6%) a single anatomic site of EHD (n = 153; 89.4%). The 5-year survival for patients with EHD was 26% compared with 58% for those without EHD (P < 0.001). Recurrence was common (84%). Among patients with EHD, R1 margin status, multiple EHD sites, and location of EHD were associated with worse survival (all P < 0.05). Patients with multiple EHD sites or aortocaval lymph node metastasis had a 5-year survival of 14% and 7%, respectively. When survival was stratified by the total number of metastases treated, the presence of EHD still had a prognostic impact, but the relative impact of EHD diminished as the total number of metastases treated increased. CONCLUSION: Concurrent resection of hepatic and EHD in well-selected patients may provide the possibility of long-term survival. The risk of recurrence, however, remains high, and a worse outcome is associated with both number of metastases and location of EHD.

What defines 'cure' after liver resection for colorectal metastases? Results after 10 years of follow-up.

BACKGROUND: During the last two decades, resection of colorectal liver metastases (CLM) in selected patients has become the standard of care, with 5-year survival rates of 25-58%. Although a substantial number of actual 5-year survivors are reported after resection, 5-year survival rates may be inadequate to evaluate surgical outcomes because a significant number of patients experience a recurrence at some point. OBJECTIVES: This study aimed to analyse longterm results and prognostic factors in liver resection for CLM in patients with complete 10-year follow-up data. METHODS: A total of 369 patients who underwent liver resection for CLM between 1985 and 1998 were identified from a bi-institutional database. Postoperative deaths and patients with extrahepatic disease were excluded. Clinicopathological prognostic factors were analysed using univariate and multivariate analyses. RESULTS: The sample included 309 consecutive patients with complete 10-year follow-up data. Five- and 10-year overall survival rates were 32% and 23%, respectively. Overall, 93% of recurrences occurred within the first 5 years of follow-up, but 11% of patients who were disease-free at 5 years developed later recurrence. Multivariate analysis demonstrated four independent negative prognostic factors for survival: more than three metastases; a positive surgical margin; tumour size >5 cm, and a clinical risk score >2. CONCLUSIONS: Five-year survival rates are not adequate to evaluate surgical outcomes of patients with CLM. Approximately one-third of actual 5-year survivors suffer cancer-related death, whereas patients who survive 10 years appear to be cured of disease.

Complications during multiorgan retrieval and pancreas preservation.

In pancreas transplantation, complications can arise at each step of the process, from the initial selection of donors and recipients through the surgical technique itself and the post-operative period, when lifelong immunosuppression is required. In the early steps, careful retrieval and preservation of the pancreas are crucial for the viability of the organ and ultimate success of the transplant. The pancreas is a low-flow gland, making it highly sensitive to transplantation conditions and presenting risk of pancreatitis due to periods of ischemia. The two groups of donors - after brain death (DBD) or after cardiac arrest (DCD) - require different strategies of retrieval and preservation to avoid or reduce the risk of complications developing during and after the transplantation. For DBD donor transplantation, multiorgan retrieval and cold preservation is the conventional technique. Asystole donor (DCD) transplantation, in contrast, can benefit from the newest technologies, such as hypothermic and especially normothermic preservation machines (referred to as NECMO), to optimize organ preservation. The latter has led to an increase in the pool of donors by facilitating recuperation of organs for transplantation that would have been discarded otherwise.

Influence of postoperative complications on long-term survival in liver transplant patients.

BACKGROUND: Liver transplant (LT) is a complex procedure with frequent postoperative complications. In other surgical procedures such as gastrectomy, esophagectomy or resection of liver metastases, these complications are associated with poorer long-term survival. It is possible this happens in LT but there are not enough data to establish this relationship. AIM: To analyze the possible influence of postoperative complications on long-term survival and the ability of the comprehensive complication index (CCI) to predict this. METHODS: Retrospective study in a tertiary-level university hospital. The 164 participants were all patients who received a LT from January 2012 to July 2019. The follow-up was done in the hospital until the end of the study or death. Comorbidity and risk after transplantation were calculated using the Charlson and balance of risk (BAR) scores, respectively. Postoperative complications were graded according to the Clavien-Dindo classification and the CCI. To assess the CCI cut-off value with greater prognostic accuracy a receiver operating characteristic (ROC) curve was built, with calculation of the area under the curve (AUC). Overall survival was estimated according to the Kaplan-Meier test and log-rank test. Groups were compared by the Mann-Whitney test. For the multivariable analysis the Cox regression was used. RESULTS: The mean follow-up time of the cohort was 37.76 (SD = 24.5) mo. A ROC curve of CCI with 5-year survival was built. The AUC was 0.826 (0.730-0.922), P < 0.001. The cut-off was calculated by means of the Youden index with a result of 35.95. The sensitivity was 84.6% and the specificity 61.3%. Survival curves for comparison of patients with CCI score < 36 vs ≥ 36 were calculated. The estimated 5-year survival was 57.65 and 43.95 months, respectively (log-rank < 0.001). This suggests that patients with more severe complications exhibit worse long-term survival. Other cut-off values were analysed. Comparison between patients with CCI < 33.5 vs > 33.5 (33.5 = median CCI value) showed estimated 5-year survival was 57.4 and 45.71 months, respectively (log-rank < 0.0001). Dividing patients according to the mode CCI value (20.9) showed an estimated 5-year survival of 60 mo for a CCI below 20.9 vs 57 mo for a CCI above 20.9 (log-rank = 0.147). The univariate analysis did not show any association between individual complications and long-term survival. A multivariate analysis was carried out to analyse the possible influence of CCI, Charlson comorbidity index, BAR and hepatocellular carcinoma on survival. Only the CCI score showed significant influence on long-term survival. CONCLUSION: A complicated postoperative period - well-defined by means of the CCI score - can influence not only short-term survival, but also long-term survival.

Validation of the Balance of Risk as a Predictor of Liver Transplant Survival in a Spanish Population.

BACKGROUND: The Balance of Risk (BAR) score is a simple test that combines donor and recipient variables to predict liver transplant success. It has been validated in different publications, with cut-off points of between 15 and 18 points proposed depending on the region. The aim of this study is to test the validity of the BAR score and to find the optimal cut-off point for our population. MATERIALS AND METHODS: A retrospective cohort of 164 liver transplant patients was selected between January 2012 and July 2019. All were older than 18 years and were treated in a Spanish tertiary-level hospital. RESULTS: The receiver operating characteristic curve between BAR and 5-year survival yields a result of 0.622 (P = .046), placing the cut-off point at ≥7 (sensitivity 61.5%, specificity 61.6%). Patients with a BAR score <7 and a BAR score ≥7 have an estimated 5-year survival of 53.91 vs 47.51 months, respectively (log rank = .032). The only 2 variables associated with increased survival were a BAR score of <7 (hazard ratio = 2.566; P < .001) and a body mass index <30 (hazard ratio = 6.667; P < .001). CONCLUSIONS: A low BAR score correlates well with liver transplant survival at 5 years. The BAR is a simple tool that should be used for donor-recipient matching. Due to the characteristics, resources, and population in our environment, a BAR score of 7 would be the optimum cut-off point for a liver transplant.

Thinning affects nutrient resorption and nutrient-use efficiency in two Pinus sylvestris stands in the Pyrenees.

Needle chemical composition was measured, and nutrient resorption, nutrient-use efficiency (NUE), and other indexes were estimated for 24 months in two contrasting natural Pinus sylvestris L. forests in the western Pyrenees in Spain. For each location (Aspurz, 650 m elevation, 7% slope; Garde, 1335 m elevation, 40% slope), there were three reference plots (P0), three plots with 20% of the basal area removed (P20), and three with 30% of the basal area removed (P30). Needle P, Ca, and Mg concentrations were higher in Garde, but N concentration was higher for Aspurz, without differences for K. Nutrient-resorption efficiency of P was higher in Aspurz, of Mg higher in Garde, and there were no differences between sites in N and K. Nutrient-resorption proficiency was significantly higher in the site with lower soil nutrient availability, i.e., for P, Ca, and Mg in Aspurz, but N in Garde (no differences in K); this may be an indicator of nutrient conservation strategy. Annual nutrient productivity (A) was higher for all nutrients in Aspurz, whereas the mean residence time (MRT) was higher in Garde in all nutrients but P. NUE was significantly higher in Garde for all nutrients but P, which was more efficiently used in Aspurz. In both sites, N, P, and K concentrations were higher in the 2002 cohort, Ca in the 2000 cohort, and maximum Mg was found in the 2001 cohort. Thinning caused a reduction of Mg concentration in the 2001 cohort in Aspurz, an increase of Ca resorption proficiency in Aspurz and Mg resorption at both sites, and reduction of P, K, and Mg nutrient response efficiency (NRE) in Garde. Thinning may have caused an increase of the C:Mg ratio through facilitating the development of more biosynthesis apparatus in a more illuminated canopy, but it seemed not to affect resorption in a significant way. Changes in NRE in Garde after thinning show that forest management can affect how trees use nutrients. Our results indicate that the strategy to optimize NUE is different in each stand. In Aspurz (a Mediterranean ecosystem), pine trees carried out resorption more efficiently, while in Garde (a continental forest), trees used nutrients for longer periods of time and reduced their efficiency in using the available soil nutrients after reduced competition by thinning.

How long is antibiotic therapy necessary after urgent cholecystectomy for acute cholecystitis?

OBJECTIVE: The objective of the study was to analyze surgical site infection (SSI) frequency with different duration antibiotic courses to establish the minimum necessary duration. METHODS: This is an observational study of prospective surveillance of 287 consecutive patients (mean age 67.8 years) operated on for acute cholecystitis of grade II severity in the first 72 h. Postoperative antibiotics had been withdrawn before diagnosis of any infection as an inclusion criterion. Patients were classified into three groups, according to therapy duration: group 1 (0-4 days, n = 45, 15.7 %); group 2 (5-7 days, n = 75, 26.1 %); and group 3 (>7 days, n = 167, 58.2 %). A multivariable analysis of risk infection was performed. RESULTS: Overall SSI frequency in groups 1, 2, and 3 was 2.2, 10.7, and 9 %, respectively. Risk analysis showed an increase in both crude and adjusted relative risks of overall infection in group 2 (crude relative risk (RR): 4.80 (0.62-37.13); adjusted RR, 2.03 (0.20-20.91)) and in group 3 (crude RR, 4.04 (0.55-29.79); adjusted RR, 2.35 (0.28-20.05)) by comparison with group 1, although without statistical significance. As a result, treatment lasting 4 days or less was not associated with overall surgical site infection incidence higher than longer treatment. CONCLUSION: Antibiotic treatment over 4 days after early cholecystectomy provides no advantage in decreasing surgical site infection incidence.