Light interception principally drives the understory response to boxelder invasion in riparian forests

Since several decades, American boxelder (Acer negundo) is replacing white willow (Salix alba) riparian forests along southern European rivers. This study aims to evaluate the consequences of boxelder invasion on understory community in riparian areas. We determined the understory species richness, composition and biomass in boxelder and white willow stands located in three riparian forests, representative of three rivers with distinct hydrological regimes. We investigated correlation of these variables to soil moisture and particle size, main soil nutrient stocks, potential nitrification and denitrification, tree canopy cover and photosynthetic active radiation (PAR) at the ground level. A greenhouse experiment was then conducted to identify the causal factors responsible for changes in the understory. The effect of soil type, PAR level and water level on the growth and the biomass production of Urtica dioica were examined. A lower plant species richness and biomass, and a modification of community composition were observed for boxelder understory in all sites, regardless of their environmental characteristics. The strongest modification that follows boxelder invasion was the decline in U. dioica, the dominant species of the white willow forest understory. These differences were mainly correlated with a lower incident PAR under boxelder canopy. The greenhouse experiment identified PAR level as the main factor responsible for the changes in U. dioica stem number and biomass. Our results indicate that adult boxelder acts as an ecosystem engineer that decreases light availability. The opportunistic invasion by boxelder leads to important understory changes, which could alter riparian ecosystem functioning

Magnetic resonance imaging (MRI) contrast agents for tumor diagnosis

10.1260/2040-2295.4.1.23Journal of Healthcare Engineering4123-4

A comprehensive overview of radioguided surgery using gamma detection probe technology

The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology

Structure evolution of [ BDTA(PEO)

The structure of three jeffamine-pyromellitimides based alternate copolymers were studied by small angle X-ray scattering measurements when they are mixed with a lithium salt. The salt addition contributes to increase the elastic domain of compounds with the longest units (B900 and B2000). By contrast, the salt induces the system having the shortest repeat units (B600) to stiffen and to crystallize

Lymphoscintigraphy in the sentinel lymph node technique for breast tumor: value of early and late images for the learning curve1

As the performance of early (H+1 to H+4) and late (D1) lymphoscintigraphic images raises organizational problems in outpatient surgery for breast cancer, only early images are generally obtained. The present study evaluated whether two series of images are better than one and defined the advantages of both methodologies. One hundred and eighteen patients with infiltrating breast carcinoma (T(0), T(1) and T(2)) were included in the study: 87 in group A (early and late images) and 31 in group B (only early images). All patients received two peritumoral injections of (99m)Tc-sulfur colloid, 15-18 MBq (group A) and <15 MBq (group B). During the operation, the patent blue bye technique was associated with radioactivity detection. The two groups were comparable for histological type and tumor size and localization. Successful localization of sentinel nodes on early lymphoscintigraphic images was significantly greater for group B. The identification of a sentinel node focus on early lymphoscintigraphy increased by 10% during the study. Sentinel node detection by the isotopic method alone, or the two methods combined, was comparable for both groups. In radioactivity detection, the count rate for sentinel nodes versus background (contralateral breast) was similar for the two groups. During the learning phase, two series of images gave a definite advantage. Subsequently, lymphoscintigraphy performed at +2 h was sufficient (the results for the two groups became indistinguishable

Do mute swan (Cygnus olor) grazing, swan residence and fishpond nutrient availability interactively control macrophyte communities?

International audienc

Learning curve for the detection of axillary sentinel lymph node in breast cancer1

AIM: Sentinel axillary lymph node (SALN) detection is a new technique. Surgeons must progress up a learning curve in order to guarantee quality and safety equivalent to axillary lymphadenectomy. To ensure accurate staging of patients this learning curve must include SALN detection and an axillary lymphadenectomy. The aim of our work was to validate the principles and evaluate the consequences of learning curve for SALN detection from a prospective series of 200 consecutive patients. METHOD: Prospective assessment was made of the detection and false negative rates, post operative morbidity as abcess and seroma, and length of hospital stay. RESULTS: We evaluated the performance from the first to the hundredth case for each surgeon. Detection rate improved to 85% after patient number 10. False negative rate was less than 6%. Post operative axillary morbidity included 11% of seromas and 2% of abcess. Mean hospital stay was 2.8 days. CONCLUSION: Multidisciplinary validation of the learning period contributes to an accurate and safe SAL

Profils sociodémographique et sportif des usagers des snowparks dans les stations de montagne des Alpes françaises

International audienc