Time filter

Source Type

Minsk, Belarus

Bottollier-Curtet M.,Association les Ecologistes de lEuziere Domaine de Restincliere | Charcosset J.-Y.,CNRS | Planty-Tabacchi A.-M.,INP | Tabacchi E.,CNRS
Plant and Soil | Year: 2015

Results: Native and exotic species did not differ in their primary chemical composition and breakdown rate. Litter breakdown rates were primarily driven by the C:N ratio with no influence of species origin. The abundance and diversity of saprophagous invertebrates of exotic and native species did not differ, but the composition did. Only one plant litter was completely degraded much earlier than expected (next litterfall) while remnant litter were still present at this time for the other species.Conclusions: The replacement of a dominant native by an exotic invasive plant species does not generally result in noticeable changes in the litter breakdown rate, which mainly depends on litter composition. Litter from quickly degrading exotic species may cause a resource discontinuity in invaded areas stabilized by river regulation.Background and aims: The study aimed to assess the effects of the potential replacement of dominant native plants by co-occurring exotic invasives on organic matter degradation in a riparian area. The questions were: i) Is there a relationship between the litter breakdown rate and species origin? ii) Is the chemical composition more relevant than species origin? iii) Does species origin influence the associated saprophagous invertebrate community?Methods: Within the riparian zone of the Garonne River (France), we conducted a litterbag experiment using pairs of native and exotic species selected in the stages of the successional gradient. © 2015, Springer International Publishing Switzerland.

Gonzalez Saldana N.,Instituto Nacional Of Pediatria | Macias Parra M.,Instituto Nacional Of Pediatria | Hernandez Porras M.,Instituto Nacional Of Pediatria | Gutierrez Castrellon P.,INP | And 2 more authors.
BMC Infectious Diseases | Year: 2014

Background: Pulmonary tuberculosis (PTB) is an infectious disease that involves the lungs and can be lethal in many cases. Tuberculosis (TB) in children represents 5 to 20% of the total TB cases. However, there are few updated information on pediatric TB, reason why the objective of the present study is to know the real situation of PTB in the population of children in terms of its diagnosis and treatment in a third level pediatric hospital.Methods: A retrospective study based on a revision of clinical files of patients less than 18 years old diagnosed with PTB from January 1994 to January 2013 at Instituto Nacional de Pediatria, Mexico City was carried out. A probable diagnosis was based on 3 or more of the following: two or more weeks of cough, fever, tuberculin purified protein derivative (PPD) +, previous TB exposure, suggestive chest X-ray, and favorable response to treatment. Definitive diagnosis was based on positive acid-fast bacilli (AFB) or culture.Results: In the 19-year period of revision, 87 children were diagnosed with PTB; 57 (65.5%) had bacteriologic confirmation with ZN staining or culture positive (in fact, 22 were ZN and culture positive), and 30 (34.5%) had a probable diagnosis; 14(16.1%) were diagnosed with concomitant disease, while 69/81 were immunized. Median evolution time was 21 days (5-150). Fever was found in 94.3%, cough in 77%, and weight loss in 55.2%. History of contact with TB was established in 41.9%. Chest X-ray showed consolidation in 48.3% and mediastinal lymph node in 47.1%. PPD was positive in 59.2%, while positive AFB was found in 51.7% cases. Culture was positive in 24/79 patients (30.4%), PCR in 20/27 (74.1%). 39 (44.8%) patients were treated with rifampin, isoniazid, and pyrazinamide while 6 (6.9%) received the former drugs plus streptomycin and 42 (48.3%) the former plus ethambutol. There were three deaths.Conclusions: PTB in pediatric population represents a diagnostic challenge for the fact that clinical manifestations are unspecific and the diagnosis is not confirmed in all cases; that is why clinical suspicion, X-ray findings and PPD are indispensable for opportune start of treatment. © 2014 González Saldaña et al.

Pampura T.V.,Russian Academy of Sciences | Probst A.,INP | Ladonin D.V.,Moscow State University | Demkin V.A.,Russian Academy of Sciences
Eurasian Soil Science | Year: 2013

Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead. © 2013 Pleiades Publishing, Ltd.

Mendez P.F.,University of Alberta | Goett G.,INP | Guest S.D.,Stantec Inc.
Welding Journal | Year: 2015

Metal transfer in submerged arc welding (SAW) has been captured in video at a rate of 10,000 frames per second by inserting a thin-gauge steel tunnel along the welding path. Precedents in the scientic literature for high-speed imaging of metal transfer in SAW are almost 40 years old using photographic film at speeds of 3000 frames per second or below. Analysis of the new videos show that at 500 A, a very chaotic, nonaxial globular metal transfer involving frequent explosions and bursts is present in both AC and DC polarities. A droplet detachment frequency of approximately 9 Hz was observed at 500-A DCEP, and 13 Hz at 500-A AC. At 1000-A DCEP, a tapering electrode tip with a buried arc was observed ejecting a molten tail through a mechanism resembling an electromagnetic kink instability. Analysis of the voltage signal indicates a l//pink noise without any indication of the events observed in the videos. Spectrometry of the arc in the weld cavity was performed, and no obvious signs of external gas entrainment were detected. Analysis of the weld cross sections show a signicant increase in penetration at 1000 A, consistent with the gouging region penetration mode observed in the videos. The technique presented here opens the door for high-speed video analysis of metal transfer and the design of complex waveforms in SAW.

Lopez-Gonzalez G.,INP | Palacios-Perales E.,IMSS | Villalpando-Canchola R.,IMSS | Iglesias-Leboreiro J.,Hospital Espanol | Bernardez-Zapata I.,Hospital Espanol
Revista Mexicana de Pediatria | Year: 2014

We present the case of a newborn in who was suspected a malignant thoracic tumor. Scan of the chest that reported under the fifth and sixth costal arches invading intrathoracic region took place. Total surgical resection, where done and the histopathologic study showed a mesenchymal hamartoma.

Discover hidden collaborations