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The spatial distribution of bacteria in bulk soil has been well studied, but little is known about the bacterial biogeography in the rhizosphere of crops. Here, we investigated bacterial distribution in bulk soil, loosely- and tightly-bound soils, from wheat fields distributed across 800,000 km 2 of the North China Plain. Bacterial community composition differed dramatically among bulk and rhizospheric soils, and bacterial diversity decreased with the root proximity. Soil pH correlated with bacterial community composition and diversity in three compartments. Bacterial community in tightly bound soil formed a hub-based network topology with higher transitivity and greater number of central nodes compared with loosely bound and bulk soils, potentially as a result of more direct ecological interactions between the members of the tightly bound soil compartment. Bulk and rhizospheric soils maintained similar compositional distance decay patterns (with equal decay rates), but distinct phylogenetic distance decay patterns (with steeper slope of tightly bound soil). Geographical distance described a relatively greater proportion of bacterial spatial distribution in tightly bound soil, compared with loosely bound soil and bulk soil. Deterministic processes dominated the assemblage of bacterial communities in all soil compartments, while phylogenetic clustering was weaker in tightly bound soil. Taken together, our results suggest distinct bacterial network structure and distribution patterns among bulk soil, loosely bound soil and tightly bound rhizospheric soil, which could possibly result in potential functional differentiation. [ABSTRACT FROM AUTHOR]

Soft tissue sarcomas are unusual malignancies comprising 1% of cancer diagnoses in the United States. Undifferentiated pleomorphic sarcoma accounts for approximately 5% of sarcomas occurring in adults. The most common site of metastasis is the lung, with other sites being bone, the brain, and the liver. Metastasis to the gastrointestinal tract has rarely been documented. We present an unusual case of high-grade pleomorphic sarcoma with metastasis to the stomach, complicated by upper gastrointestinal bleeding.

Background: Relative to hemoglobin A(1c) (HbA(1c)), percentage of glycated albumin (GA%) more accurately reflects recent glycemic control in diabetic hemodialysis (HD) patients., Methods: To determine the accuracy of glycemic assays in a larger sample including patients on peritoneal dialysis (PD), HbA(1c) and GA% were measured in 519 diabetic subjects: 55 on PD, 415 on HD, and 49 non-nephropathy controls., Results: Mean +/- SD serum glucose levels were higher in HD and PD patients relative to non-nephropathy controls (HD 169.7 +/- 62 mg/dL, PD 168.6 +/- 66 mg/dL, controls 146.1 +/- 66 mg/dL; p = 0.03 HD vs controls, p = 0.13 PD vs controls). GA% was also higher in HD and PD patients (HD 20.6% +/- 8.0%, PD 19.0% +/- 5.7%, controls 15.7% +/- 7.7%; p < 0.02 HD vs controls and PD vs controls). HbA(1c) was paradoxically lower in dialysis patients (HD 6.78% +/- 1.6%, PD 6.87% +/- 1.4%, controls 7.3% +/- 1.4%; p = 0.03 HD vs controls, p = 0.12 PD vs controls). The serum glucose/HbA(1c) ratio differed significantly between dialysis patients and controls (p < 0.0001 HD vs controls, p = 0.002 PD vs controls), while serum glucose/GA% ratio was similar across groups (p = 0.96 HD vs controls, p = 0.64 PD vs controls). In best-fit multivariate models with HbA(1c) or GA% as outcome variable, dialysis status was a significant predictor of HbA(1c) but not GA%., Conclusions: The relationship between HbA(1c) and GA% differs in diabetic patients with end-stage renal disease who perform either PD or HD compared to those without nephropathy. HbA(1c) significantly underestimates glycemic control in peritoneal and hemodialysis patients relative to GA%.

Prosapia simulans (Walker) is an important spittlebug species that attacks forage grasses of the genus Brachiaria (Trin.) Griseb. from Mexico to Colombia. This, and several other species of spittlebugs, cause important economic losses to the livestock production industry. Development of resistant cultivars is regarded as the best method of control. In the present study we used taxonomic keys, dissection of male genitalia and RAPD-PCR patterns to reconfirm the identity of P. simulans specimens collected in Colombia and Mexico. We were able to reconfirm that P. simulans occurs as a pest of Brachiaria from Mexico to Colombia. We also studied the levels and mechanisms of resistance present in 34 Brachiaria hybrids developed by CIAT. Infestations were made with six eggs per plant. We used 10 replications (plants) per genotype in a completely randomized design. Seven hybrids were found to be susceptible, 16 showed intermediate resistance and 11 were resistant. Antibiosis was the mechanism of resistance expressed in resistant hybrids as well as in the resistant checks CIAT 6294 and CIAT 36062. Tolerance was absent. The genotypes BRX 4402 and CIAT 0606 were classified as highly susceptible.