Root and Shoot Contribution to Carbon and Nitrogen Inputs in the Topsoil Layer in No-Tillage Crop Systems under Subtropical Conditions

Recycling of carbon (C) and nitrogen (N) from plants into soils is decisive for maintaining soil organic matter and soil fertility. Therefore, we quantified plant biomass and C and N in the shoots and roots from the topsoil layer for a wide range of annual crops grown under subtropical conditions. We grew 26 species, 13 main crops, and 13 cover crops, in the field in standard sowing arrangements. Root biomass was recovered from the 0.00-0.20 m soil layer at flowering, and shoot biomass was measured at flowering for all crops and at maturity only for the main crops. Root dry matter (DM) exhibited an average of 14.9 ± 5.7 % of the total shoot biomass at flowering, and the mean shoot DM to root DM ratio was 6.9 (2.8-15.0) for the 26 crops considered. Leguminous species had less root DM (0.5 to 1.0 Mg ha-1) than grass species (1.1 to 2.3 Mg ha-1). The shoot C to root C ratio varied consistently with DM, while the root N to shoot N ratio varied considerably among species. Proportionally more biomass, C, and N was allocated to the root systems of grasses (Poaceae species) than non-grass species (especially Fabaceae species). The findings of this study contribute to designing rotations to include species that promote cycling of N and have high potential for adding C to the soil through roots. In this sense, the use of intercropped grasses and legumes is a promising strategy, especially for cover crops

Experimental trial on surgical treatment for transverse fractures of the proximal phalanx: technique using intramedullary conical compression screw versus lateral compression plate

AbstractObjectiveTo compare the mechanical parameters between two methods for stabilization through compression: 1.5mm axial compression plate versus conical compression screw used as an intramedullary tutor.MethodsPolyurethane models (Sawbone®) that simulated transverse fractures of the proximal phalanx were used. The models were divided into three groups: lateral plate, conical screw and no implant.ResultsGreater force was needed to result in fatigue in the synthesis using an intramedullary plate. Thus, this model was proven to be mechanically superior to the model with the lateral plate.ConclusionStabilization using the Acutrak® screw for treating fractures in the model used in this trial presents mechanical results that are statistically significantly superior to those from the axial compression technique using the lateral plate (Aptus Hand®)

Root and Shoot Contribution to Carbon and Nitrogen Inputs in the Topsoil Layer in No-Tillage Crop Systems under Subtropical Conditions

Recycling of carbon (C) and nitrogen (N) from plants into soils is decisive for maintaining soil organic matter and soil fertility. Therefore, we quantified plant biomass and C and N in the shoots and roots from the topsoil layer for a wide range of annual crops grown under subtropical conditions. We grew 26 species, 13 main crops, and 13 cover crops, in the field in standard sowing arrangements. Root biomass was recovered from the 0.00-0.20 m soil layer at flowering, and shoot biomass was measured at flowering for all crops and at maturity only for the main crops. Root dry matter (DM) exhibited an average of 14.9 ± 5.7 % of the total shoot biomass at flowering, and the mean shoot DM to root DM ratio was 6.9 (2.8-15.0) for the 26 crops considered. Leguminous species had less root DM (0.5 to 1.0 Mg ha-1) than grass species (1.1 to 2.3 Mg ha-1). The shoot C to root C ratio varied consistently with DM, while the root N to shoot N ratio varied considerably among species. Proportionally more biomass, C, and N was allocated to the root systems of grasses (Poaceae species) than non-grass species (especially Fabaceae species). The findings of this study contribute to designing rotations to include species that promote cycling of N and have high potential for adding C to the soil through roots. In this sense, the use of intercropped grasses and legumes is a promising strategy, especially for cover crops

Laparoscopic versus Open Appendectomy : retrospective analyses

Introdução: As técnicas de apendicectomia convencional (aberta) e videolaparoscópica (VLP) vêm sendo amplamente estudadas com o objetivo de definir uma técnica padrão-ouro. No entanto, os estudos até hoje realizados não foram capazes de uniformizar a indicação cirúrgica mais adequada. Objetivo: Este estudo tem como objetivo analisar a casuística do Hospital de Clínicas de Porto Alegre (HCPA) e comparar os resultados de apendicectomias obtidos através da técnica convencional com aqueles encontrados através do uso da videolaparoscopia. Métodos: Estudo descritivo de uma coorte histórica de 348 pacientes maiores de 12 anos submetidos à apendicectomia no HCPA no período de 01/01/2004 a 31/12/2005. Resultados: O tempo cirúrgico, tempo de internação hospitalar e taxa de abscesso intra-abdominal não apresentam diferença estatisticamente significativa. A técnica VLP foi superior à convencional quando comparada a taxas de infecção de ferida operatória (p < 0,001). A videolaparoscopia foi mais indicada em mulheres e mais realizada por profissionais com maior experiência (p < 0,001). Conclusão: A cirurgia aberta mostrou significativas desvantagens em comparação à videolaparoscopia, como uma maior taxa de infecção em ferida posoperatória. Entretanto, ainda são necessários estudos prospectivos complementares para melhor comparar as duas técnicas. Portanto, a definição da técnica cirúrgica deve ser baseada principalmente na experiência do cirurgião e nas características clínicas de cada paciente.Background: Conventional (open) and laparoscopic appendectomies are being widely studied in order to define a gold standard technique. Nevertheless, the studies until now could not be able to standardize the most adequate surgical indication. Objective: To analyze our hospital’s case series and compare the results obtained using open appendectomy with the results found with laparoscopic technique. Methods: Descriptive historical cohort study of 348 patients older than 12 years-old that underwent either open or laparoscopic appendectomies from 01/01/2004 to 12/31/2005 Results: Operative time, length of stay in hospital and intra-abdominal abscess rate were not statistically significant. Laparoscopic technique was superior to open procedure when wound infection (p < 0.001) was compared. Also, laparoscopy was more indicated among women and it was more performed by experienced professionals (p < 0.001). Conclusion: Open appendectomy showed significant disadvantages when compared to laparoscopic surgery, like a higher post-operatory wound infection rate. However, additional prospective studies are needed to better compare the two procedures. Therefore, surgical technique must be defined based on the experience of the surgeon and the clinical condition of the patient

Mineralização do carbono da palha de aveia e dejetos de suínos aplicados na superfície ou incorporados ao solo

A mineralização do C de dejetos de suínos e de palhas de cereais é um processo ainda relativamente pouco estudado no Brasil. O objetivo deste trabalho foi avaliar a mineralização do C da palha de aveia, dos dejetos líquidos de suínos e da cama sobreposta de suínos, aplicados na superfície ou incorporados em um Argissolo Vermelho distrófico arênico, em condições de laboratório. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições dos seguintes tratamentos: solo; solo + palha incorporada; solo + palha em superfície; solo + cama sobreposta incorporada; solo + cama sobreposta em superfície; solo + dejetos líquidos incorporados; solo + dejetos líquidos em superfície; solo + palha + dejetos líquidos incorporados; e solo + palha + dejetos líquidos em superfície. Durante 80 dias de incubação, a emissão de CO2 foi medida continuamente. Ao final desse período, observou-se que foram mineralizados 59 % do C dos dejetos líquidos e apenas 23 % do C da cama sobreposta. A incorporação dos materiais orgânicos ao solo não resultou em maior mineralização do C, quando comparado à permanência desses na superfície do solo. O N amoniacal, aplicado com os dejetos líquidos de suínos, não aumentou a mineralização do C da palha de aveia.The C mineralization of pig manure and cereal straw is still relatively little studied in Brazil. The aim of this work was to evaluate C mineralization of oat straw, pig slurry and pig deep-litter, applied on the surface or incorporated in a Hapludalf soil, in laboratory conditions. The experiment was a completely randomized design with four replications of the following treatments: soil; soil + incorporated straw; soil + surface straw; soil + incorporated pig deep-litter, soil + surface pig deep-litter, soil + incorporated pig slurry; soil + surface pig slurry; soil + incorporated straw + pig slurry; and soil + surface straw + pig slurry. During the 80 days of incubation, the CO(2) emission was measured continuously. After this period, 59 % of pig slurry C had been mineralized and only 23 % of deep-litter C. The soil incorporation of organic materials did not result in. higher C mineralization, compared with organic material on the soil surface. Ammoniacal N, applied with pig slurry did not increase C oat straw mineralization

Hospital transmission of multidrug-resistant mycobacterium tuberculosis in Rosario, Argentina

Multidrug-resistant tuberculosis has emerged over the last two years at Carrasco Hospital, located in Rosario city. Nosocomial transmission among 7 AIDS patients admitted into the same ward between June and December/94 was supported by temporal clustering of cases, matching drug susceptibility, and identical IS6110 fingerprints. Among 8 non-HIV chronic cases without evidence of reciprocal contact outside the hospital, two additional clusters of 2 and 4 cases, respectively, were identified. The latter was found to be generated by a strain genetically related to the one that infected AIDS patients. It is hypothesized that an ancestor strain, common to both, might have been brought into the hospital long before the outbreak was first suspected

Hospital transmission of multidrug-resistant mycobacterium tuberculosis in Rosario, Argentina

Multidrug-resistant tuberculosis has emerged over the last two years at Carrasco Hospital, located in Rosario city. Nosocomial transmission among 7 AIDS patients admitted into the same ward between June and December/94 was supported by temporal clustering of cases, matching drug susceptibility, and identical IS6110 fingerprints. Among 8 non-HIV chronic cases without evidence of reciprocal contact outside the hospital, two additional clusters of 2 and 4 cases, respectively, were identified. The latter was found to be generated by a strain genetically related to the one that infected AIDS patients. It is hypothesized that an ancestor strain, common to both, might have been brought into the hospital long before the outbreak was first suspected

Ensaio experimental para tratamento cirúrgico das fraturas transversas da falange proximal - Técnica com parafuso intramedular cônico de compressão versus placa de compressão lateral

resumo Objetivo: Comparar os parâmetros mecânicos entre dois métodos de estabilização por com pressão: placa de compressão axial de 1,5 mm com o parafuso cônico de compressão usado como tutor intramedular. Métodos: Foram usados modelos de poliuretano (Sawbone(r)) que simulam a fratura da falange proximal transversa, divididos em três grupos (placa lateral, parafuso cônico, sem implante). Resultados: Há necessidade de uma maior força para resultar na fadiga da síntese com para fuso intramedular. Comprova-se, assim, a supremacia mecânica desse sobre o modelo com a placa lateral. Conclusão: A estabilização com o parafuso Acutrak(r), no tratamento das fraturas no modelo adotado neste ensaio, apresenta resultados mecânicos superiores e estatisticamente sig nificativos em comparacão com a técnica de compressão axial com o uso da placa lateral (Aptus Hand (r))