Segmented lordotic angles to assess lumbosacral transitional vertebra on EOS

Purpose: To test the vertical posterior vertebral angles (VPVA) of the most caudal lumbar segments measured on EOS to identify and classify the lumbosacral transitional vertebra (LSTV). Methods: We reviewed the EOS examinations of 906 patients to measure the VPVA at the most caudal lumbar segment (cVPVA) and at the immediately proximal segment (pVPVA), with dVPVA being the result of their difference. Mann\u2013Whitney, Chi-square, and ROC curve statistics were used. Results: 172/906 patients (19%) had LSTV (112 females, mean age: 43 \ub1 21 years), and 89/172 had type I LSTV (52%), 42/172 type II (24%), 33/172 type III (19%), and 8/172 type IV (5%). The cVPVA and dVPVA in non-articulated patients were significantly higher than those of patients with LSTV, patients with only accessory articulations, and patients with only bony fusion (all p <.001). The cVPVA and dVPVA in L5 sacralization were significantly higher than in S1 lumbarization (p <.001). The following optimal cutoff was found: cVPVA of 28.2\ub0 (AUC = 0.797) and dVPVA of 11.1\ub0 (AUC = 0.782) to identify LSTV; cVPVA of 28.2\ub0 (AUC = 0.665) and dVPVA of 8\ub0 (AUC = 0.718) to identify type II LSTV; cVPVA of 25.5\ub0 (AUC = 0.797) and dVPVA of 12 7.5\ub0 (AUC = 0.831) to identify type III\u2013IV LSTV; cVPVA of 20.4\ub0 (AUC = 0.693) and dVPVA of 12 1.8\ub0 (AUC = 0.665) to differentiate type II from III\u2013IV LSTV; cVPVA of 17.9\ub0 (AUC = 0.741) and dVPVA of 12 4.5\ub0 (AUC = 0.774) to differentiate L5 sacralization from S1 lumbarization. Conclusion: The cVPVA and dVPVA measured on EOS showed good diagnostic performance to identify LSTV, to correctly classify it, and to differentiate L5 sacralization from S1 lumbarization

Variações qualitativas e quantitativas na microbiota do solo e na fixação biológica do nitrogênio sob diferentes manejos com soja Qualitative and quantitative changes in soil microbiota and biological nitrogen fixation under different soybean managements

Neste estudo foram avaliados atributos qualitativos e quantitativos da microbiota do solo, visando monitorar alterações por diferentes manejos do solo e das culturas. As avaliações foram feitas em um ensaio a campo, conduzido há 14 anos em Londrina, PR, sob plantio convencional (PC) ou plantio direto (PD) e com sucessão (S) (soja/trigo) ou rotação (R) (tremoço/milho/aveia-preta/soja/trigo/soja/trigo/soja) de culturas, quando todos os sistemas estavam com soja no estádio de florescimento pleno. Os incrementos no C e N da biomassa microbiana (CBM e NBM) no PD foram de 114 e 157 %, respectivamente, em comparação ao PC; além disso, o quociente metabólico (qCO2) foi inferior em 37 % no PD, indicando maior eficiência metabólica da microbiota do solo. Não foram detectadas diferenças nesses atributos em função dos sistemas de rotação e sucessão de culturas. A diversidade genética da comunidade bacteriana total do solo foi superior no PD e inferior no PC com sucessão de culturas. Em relação à fixação biológica do N2, a massa, o N total e a fração de N-ureídos acumulados na parte aérea e a eficiência dos nódulos em fixar N2 foram superiores no PD. A diversidade genética dos rizóbios foi afetada, principalmente, pelo manejo das culturas, sendo superior com a rotação, provavelmente pelo maior número de espécies de plantas. Contudo, com a rotação ocorreu decréscimo na eficiência do processo de fixação biológica do N2, o que pode estar relacionado com os teores mais elevados de N no solo, ou com a menor pressão de seleção por bactérias eficientes. Desse modo, para microrganismos do solo com função específica, como os rizóbios, a diversidade genética pode ser distinta da funcionalidade.<br>In this study, quantitative and qualitative microbiological parameters were evaluated to detect differences related to soil and crop management. The study was carried out in a field experiment installed 14 years ago on a Rhodic Eutrudox, in Londrina, PR, Brazil. Treatments were a combination of a crop sequence (S) (soybean/wheat) and a crop rotation (R) (lupin/maize/black oat/soybean/wheat/soybean/wheat/soybean), either under conventional tillage (CT) or no-tillage (NT). Evaluations were performed when all systems were under the soybean cropping season, at full flowering. Amounts of microbial biomass carbon and nitrogen (MB-C and MB-N, respectively) were 114 and 157 % higher in NT than in CT. Furthermore, the metabolic quotient (qCO2) was lower under NT, indicating higher metabolic efficiency of the soil microbes. These parameters were not affected by the crop sequence/rotation. Genetic diversity of the total soil bacterial community was higher under NT and lower in the CT system with crop sequence. Regarding the biological N2 fixation, it was found that plant biomass, total N and fraction of N-ureides in shoots, as well as nodule efficiency, were higher under NT. Genetic diversity of rhizobia was affected mainly by crop management and was higher under crop rotation, probably due to the greater number of plant species. However, crop rotation decreased the efficiency of the biological N2 fixation process, which may be related to more abundant N in the soil or to a lower selection pressure for efficient rhizobia. For soil microbes with specific functions, e.g., rhizobia, genetic diversity may therefore differ from functionality