Towards accurate monitoring of water content in woody tissue across tropical forests and other biomes.

Forest ecosystems face increasing drought exposure due to climate change, necessitating accurate measurements of vegetation water content to assess drought stress and tree mortality risks. While Frequency Domain Reflectometry offers a viable method for monitoring stem water content by measuring dielectric permittivity, challenges arise from uncertainties in sensor calibration linked to wood properties and species variability, impeding its wider usage. We sampled tropical forest trees and palms in eastern Amazônia, to evaluate how sensor output differences are controlled by wood density, temperature and taxonomic identity. Three individuals per species were felled and cut into segments (total n = 262), within a diverse dataset comprising five dicotyledonous tree-and three monocotyledonous palm species on a wide range of wood densities. Water content was estimated gravimetrically for each segment using a temporally explicit wet-up/dry-down approach, and the relationship with the dielectric permittivity was examined. Woody tissue density had no significant impact on the calibration, but species identity and temperature significantly affected sensor readings. The temperature artefact was quantitatively important at large temperature differences which may have led to significant bias of daily and seasonal water content dynamics in previous studies. We established the first tropical tree and palm calibration equation that performed well for estimating water content. Notably, we demonstrated that the sensitivity remained consistent across species, enabling the creation of a simplified one-slope calibration for accurate, species-independent measurements of relative water content. Our one-slope calibration serves as a general, and species-independent standard calibration for assessing relative water content in woody tissue, offering a valuable tool for quantifying drought responses and stress in trees and forest ecosystems.

Risk/Benefit Communication about Food-A Systematic Review of the Literature.

A systematic review relevant to the following research questions was conducted (1) the extent to which different theoretical frameworks have been applied to food risk/benefit communication and (2) the impact such food risk/benefit communication interventions have had on related risk/benefit attitudes and behaviors. Fifty four papers were identified. The analysis revealed that (primarily European or US) research interest has been relatively recent. Certain food issues were of greater interest to researchers than others, perhaps reflecting the occurrence of a crisis, or policy concern. Three broad themes relevant to the development of best practice in risk (benefit) communication were identified: the characteristics of the target population; the contents of the information; and the characteristics of the information sources. Within these themes, independent and dependent variables differed considerably. Overall, acute risk (benefit) communication will require advances in communication process whereas chronic communication needs to identify audience requirements. Both citizen's risk/benefit perceptions and (if relevant) related behaviors need to be taken into account, and recommendations for behavioral change need to be concrete and actionable. The application of theoretical frameworks to the study of risk (benefit) communication was infrequent, and developing predictive models of effective risk (benefit) communication may be contingent on improved theoretical perspectives.

Barriers for progress in salt reduction in the general population. An international study.

Salt reduction is important for reducing hypertension and the risk of cardiovascular events, nevertheless worldwide salt intakes are above recommendations. Consequently strategies to reduce intake are required, however these require an understanding of salt intake behaviours to be effective. As limited information is available on this, an international study was conducted to derive knowledge on salt intake and associated behaviours in the general population. An online cohort was recruited consisting of a representative sample from Germany, Austria, United States of America, Hungary, India, China, South Africa, and Brazil (n=6987; aged 18-65 years; age and gender stratified). Participants completed a comprehensive web-based questionnaire on salt intake and associated behaviours. While salt reduction was seen to be healthy and important, over one third of participants were not interested in salt reduction and the majority were unaware of recommendations. Salt intake was largely underestimated and people were unaware of the main dietary sources of salt. Participants saw themselves as mainly responsible for their salt intake, but also acknowledged the roles of others. Additionally, they wanted to learn more about why salt was bad for health and what the main sources in the diet were. As such, strategies to reduce salt intake must raise interest in engaging in salt reduction through improving understanding of intake levels and dietary sources of salt. Moreover, while some aspects of salt reduction can be globally implemented, local tailoring is required to match level of interest in salt reduction. These findings provide unique insights into issues surrounding salt reduction and should be used to develop effective salt reduction strategies and/or policies.

Neurological complications and pleural lavage with a fibrinolytic agent. A two-case report.

We report on an unusual, albeit potentially severe, complication of the performance of a pleural lavage with streptokinase in two patients demonstrating parapneumonic pleural effusion. During the time they underwent repeated pleural lavages with saline and streptokinase, they suddenly demonstrated focal neurological signs. As a result of early diagnosis and emergency hyperbaric oxygenation, both patients recovered without delayed sequelae. Air embolism is a potentially severe complication which can occur during pleural lavage. Whether streptokinase increases the risk of opening a latent vascular breach cannot be definitely established, but clinicians should be aware of this risk. In this context, the onset of acute focal neurological signs should suggest the possibility of air embolism and lead to the transfer of the patient close to a hyperbaric facility within a few hours.

Respiratory complications after surgical treatment of esophageal cancer. A study of 309 patients according to the type of resection.

This study analyzes the respiratory complications in a retrospective study of 309 resections for esophageal cancer. We mainly performed two types of resections according to the height of the tumor: the Ivor-Lewis resection for middle thoracic lesions (182 cases), and the Akiyama resection for upper thoracic lesions (127 cases). We compared the respiratory complications occurring after these two procedures. Our overall mortality and morbidity rates were, respectively, 9% and 37%. In our series, the mortality rate was 4 times higher after the Akiyama procedure than after the Ivor-Lewis procedure, and the morbidity was twice as high. Respiratory complications accounted for 64% of the postoperative deaths. The Akiyama procedure yielded more respiratory complications, especially isolated bronchopneumonia and necrosis of the trachea or of the right or left main bronchus. Respiratory complications accounted for 53% of morbidity, mainly recurrent nerve paralysis with false passages and stasis in the transplant. Both are directly related to the surgical act and often result in bronchopneumonia. Rather than the surgical technique or the skill of the surgeon, it seems that local factors, such as the position of the tumor on the esophagus, increased the incidence of recurrent nerve paralysis following the Akiyama procedure. However, the rate of respiratory complications remained high after the Ivor-Lewis procedure. Patient history, which sometimes included a previous ENT cancer, must be taken into account, as well as the gravity of the operation and the duration of the intubation. Frequent false passages and reflux must be fought by intensive physiotherapy and, when necessary, by early tracheotomy before the patient develops postoperative acute respiratory distress syndrome.

[Result of surgery of esophageal cancer. Analysis of a series of 349 cases based on resection methods]. / Résultat de la chirurgie du cancer de l'oesophage. Analyse d'une série de 349 cas selon les types d'exérèse.

Despite obvious improvements in operative and postoperative management after esophageal resection, surgical treatment of esophageal cancer is still disappointing in terms of long term results. The purpose of the present study was to verify these poor results statistically and to discuss the value of a modified therapeutic approach. Our experience covers 349 esophageal resections performed between 1979 and 1992. These patients were predominantly males (93%) with squamous cell carcinoma (86%). The majority of the patients underwent either an Ivor-Lewis (52%) or an Akiyama procedure (36%). Survival was estimated according to the Kaplan-Meier model. Influence of parameters such as sex, histology, type of resection and TNM-staging was assessed with the "log-rank" test. The perioperative mortality was 10%. The non-fatal morbidity rate was 34%, and was most often related to anastomotic leaks. Pathological staging disclosed a majority of T3 tumors (71%). The overall survival rate was 54% at one year, 28% at 2 years and 9% at 5 years. This survival was not influenced by either histology (squamous cell or adenocarcinoma), the type of resection (Ivor-Lewis or Akiyama procedure). A slightly superior survival rate was observed after Ivor-Lewis procedure and is explained by a lower postoperative complication rate. In particular, diffuse N2 disease (abdominal and mediastinal) had a worse prognosis than localized N2. N1 disease was probably understaged, since survival was comparable to localized N2. The natural history was characterized by development of metastases (43%) rather than by local recurrence. We conclude that these results may justify surgery for palliation of dysphagia in so far as the post-operative morbidity is reduced, as we observed with Ivor-Lewis procedures. However, improvement of long-term survival requires a multimodality oncologic approach.

[The risks of surgical training. A study apropos of 348 pneumonectomies]. / Les risques de l'apprentissage de la chirurgie. Etude à propos de 348 pneumonectomies.

On the basis of the retrospective study of a series of 348 pneumonectomies, the authors have attempted to assess whether the risks of postoperative complications were increased if the operation was carried out by trainee surgeons. All operations were performed for cancer, with a stapler being used for bronchial suture. The patients were classified in three groups according to the surgeon: 133 (38%) were operated by an University professor (group I, 2 surgeons), 171 (49%) by chief resident or hospital practitioner (group II, 3 surgeons) and 44 (13%) by an intern (group III, 14 surgeons). The homogeneity of the 3 groups was checked with alpha X2 test. The study dealt with the overall mortality as well as with the specific complications of pneumonia, namely empyema and bronchopleural fistulae. The overall postoperative mortality rate was similar in the 3 groups (respectively 8%, 8% and 5%), as well as the occurrence of empyema (respectively 4%, 3% and 5%). A difference that, though not significant statistically, is not negligible, appears for bronchopleural fistulae, which complicate 9% of the operations carried out by interns vs. 4% in the other 2 categories. These observations challenge a number of studies claiming that surgery performed by inexperienced surgeons is innocuous. However, pneumonectomy is an essential step in the training to thoracic surgery, so that no candidate with sufficient surgical maturity should be prevented from performing it.

Diabetes, hyperinsulinemia, and hyperlipidemia in small aboriginal community in northern Australia.

A small rural Aboriginal community in northern Australia was surveyed for diabetes, impaired glucose tolerance (IGT), hyperinsulinemia, and lipid levels. Of the 122 adults greater than 17 yr of age who participated (95% response rate), 11.5% had diabetes, 7.4% had IGT, and the remaining 81.1% had normal glucose tolerance. Both diabetes and IGT were strongly age related. This high frequency of diabetes occurred, despite the population being relatively lean. Although the body mass index (BMI) increased with age in both men and women, only 25% of the population overall had BMI greater than 25 kg/m2. There were wide ranges of insulin responses to glucose, with the upper tertile of 2-h insulin levels being more than seven times higher than the lower tertile (144 +/- 13 vs. 19 +/- 1 mU/L). Hyperinsulinemia was associated with IGT, elevated triglycerides, and lower high-density lipoprotein cholesterol levels. Lipid abnormalities were much more frequent among men than women. Cholesterol levels were an average of 0.55 mM higher and triglycerides an average of 1.05 mM higher in men than in women, and both increased with age. In conclusion, this small isolated Aboriginal population from northern Australia had an unexpectedly high frequency of diabetes (in view of their relative leanness) in association with a high frequency of metabolic abnormalities indicative of insulin resistance (hyperinsulinemia, IGT, hypertriglyceridemia).

[Treatment of mild and moderate hypertension with the use of captopril alone or combined with hydrochlorothiazide. A multicenter study]. / Tratamento da hipertensão arterial leve e moderada com o uso de captopril isolado ou associado à hidroclorotiazida. Estudo multicêntrico.

The efficacy of captopril 25 mg/day as monotherapy or when necessary, in association with hydrochlorothiazide 25 mg/day, was studied during three months in 472 patients, average age 45 (17-59) years, 51% males with mild (73%) 95 less than PAD less than 104 mmHg, and moderate (27%) arterial hypertension 104 less than PAD less than 114 mmHg. Were included in the study hypertensive patients with previous antihypertensive therapy or when in the course of any previous antihypertensive treatment (52.4%) blood pressure control were not observed and side effects compromised patient's compliance. Captopril 25 mg/day was used once a day as single dose or subdivided in two daily doses (12.5 mg b.i.d.), during 30 days. If blood pressure was not normalized or dyastolic blood pressure drop was not equal or bigger than 10% after this period, it was added hydrochlorothiazide 25 mg/day. After three months under treatment, 411 (87%) patients normalized their dyastolic blood pressure DBP (less than 90 mmHg), from them, 273 (57.6%) had received only captopril and the others 138 (29.4%) with the addition of hydrochlorothiazide. The drop of mean arterial pressure, MAP = 2 DBP + 1 SBP was in average, 17.3 mmHg, in the 3 patients whose blood pressure normalized with captopril alone, and in average of 18.5 mmHg in those patients requiring addition of hydrochlorothiazide (difference without statistical significance). A small decrease of body weight, but with statistical significance (p less than 0.001) were observed during the use of captopril as monotherapy. Expressive reduction of side effects were observed during the period under captopril related to the period with previous antihypertensive therapy.

[Repeated surgery in primary bronchial cancer. Apropos of 18 cases]. / La chirurgie itérative dans le cancer bronchique primitif. A propos de 18 cas.

Primary lung cancer treated by surgery may re-develop on another site. Eighteen patients were re-operated upon over a 14-year period (1970-1983) in the Thoracic Surgery Unit of Strasbourg (Prof. J. P. Witz) for a second cancerous localization. Complications and post-operative mortality were more frequent with ipsilateral excisions (8 cases) than with contralateral excisions (10 cases); this may be due to the technical difficulties associated with complementary pneumonectomy in a previously affected hemithorax. The diagnosis, usually obtained by radiography of the chest, resulted from regular, long-term surveillance of patients operated upon for lung cancer. In spite of the small number of cases in this series (1.5% of excisions for lung cancer during that period), there is no doubt that to re-operate patients with a new localization of cancer is the best therapeutic solution.

[Value of a plan for surveillance of patients operated on for bronchial cancer]. / Intérêt d'un plan de surveillance des malades opérés pour cancer bronchique.

The modalities and results of surveillance of 578 patients operated upon for bronchial cancer are reported. Planned surveillance, introduced in 1981, is compared with the surveillance carried out from 1977 to 1980. The plan includes 4 radiological and clinical examinations during the 1st year, 3 during the 2nd year, 2 during the 3rd year and 1 per year thereafter. Bronchial fibroscopy is performed 9 and 18 months after surgery. In the 3rd post-operative month 10% of the patients had died, 4% had been lost sight of, and 86% had presented themselves for control examination. Regularity in attending control sessions has improved since planned surveillance was introduced: on average, the number of examinations is complied with, without modifications in the out-patient/in-patient ratio. Endoscopies are performed in 70% of the cases. Multiplying control examinations does not noticeably increases the number of pathological findings. Many relapses diagnosed on symptomatic grounds were, in fact, inaccessible to radiology and endoscopy. Five out of 19 local-regional relapses were diagnosed by fibroscopy. It is concluded that there is no need to increase the number of consultations, and that the complementary examinations performed should be more carefully selected.