Growth-profile configuration for specific deformations of tubular organs: A study of growth-induced thinning and dilation of the human cervix.

Growth is a significant factor that results in deformations of tubular organs, and particular deformations associated with growth enable tubular organs to perform certain physiological functions. Configuring growth profiles that achieve particular deformation patterns is critical for analyzing potential pathological conditions and for developing corresponding clinical treatments for tubular organ dysfunctions. However, deformation-targeted growth is rarely studied. In this article, the human cervix during pregnancy is studied as an example to show how cervical thinning and dilation are generated by growth. An advanced hyperelasticity theory called morphoelasticity is employed to model the deformations, and a growth tensor is used to represent growth in three principle directions. The computational results demonstrate that both negative radial growth and positive circumferential growth facilitate thinning and dilation. Modeling such mixed growth represents an advancement beyond commonly used uniform growth inside tissues to study tubular deformations. The results reveal that complex growth may occur inside tissues to achieve certain tubular deformations. Integration of further biochemical and cellular activities that initiate and mediate such complex growth remains to be explored.

Dairy farm age and resistance to antimicrobial agents in Escherichia coli isolated from dairy topsoil.

Antimicrobial agent usage is common in animal agriculture for therapeutic and prophylactic purposes. Selective pressure exerted by these antimicrobials on soil bacteria could result in the selection of strains that are resistant due to chromosomal- or plasmid-derived genetic components. Multiple antimicrobial resistances in Escherichia coli and the direct relationship between antimicrobial agent use over time has been extensively studied, yet the relationship between the age of an animal agriculture environment such as a dairy farm and antibiotic resistance remains unclear. Therefore, we tested the hypothesis that antimicrobial-resistance profiles of E. coli isolated from dairy farm topsoil correlate with dairy farm age. E. coli isolated from eleven dairy farms of varying ages within Roosevelt County, NM were used for MIC determinations to chloramphenicol, nalidixic acid, penicillin, tetracycline, ampicillin, amoxicillin/clavulanic acid, gentamicin, trimethoprim/sulfamethoxazole, cefotaxime, and ciprofloxacin. The minimum inhibitory concentration values of four antibiotics ranged 0.75 to >256 µg/ml, 1 to >256 µg/ml, 12 to >256 µg/ml, and 0.75 to >256 µg/ml for chloramphenicol, nalidixic acid, penicillin, and tetracycline, respectively. The study did not show a direct relationship between antibiotic resistance and the age of dairy farms.

Assessment of student skills for critiquing published primary scientific literature using a primary trait analysis scale.

Instructor evaluation of progressive student skills in the analysis of primary literature is critical for the development of these skills in young scientists. Students in a senior or graduate-level one-semester course in Immunology at a Masters-level comprehensive university were assessed for abilities (primary traits) to recognize and evaluate the following elements of a scientific paper: Hypothesis and Rationale, Significance, Methods, Results, Critical Thinking and Analysis, and Conclusions. We tested the hypotheses that average recognition scores vary among elements and that scores change with time differently by trait. Recognition scores (scaled 1 to 5), and differences in scores were analyzed using analysis of variance (ANOVA), regression, and analysis of covariance (ANCOVA) (n = 10 papers over 103 days). By multiple comparisons testing, we found that recognition scores statistically fell into two groups: high scores (for Hypothesis and Rationale, Significance, Methods, and Conclusions) and low scores (for Results and Critical Thinking and Analysis). Recognition scores only significantly changed with time (increased) for Hypothesis and Rationale and Results. ANCOVA showed that changes in recognition scores for these elements were not significantly different in slope (F1,16 = 0.254, P = 0.621) but the Results trait was significantly lower in elevation (F1,17 = 12.456, P = 0.003). Thus, students improved with similar trajectories, but starting and ending with lower Results scores. We conclude that students have greatest difficulty evaluating Results and critically evaluating scientific validity. Our findings show extant student skills, and the significant increase in some traits shows learning. This study demonstrates that students start with variable recognition skills and that student skills may be learned at differential rates. Faculty can use these findings or the primary trait analysis scoring scale to focus on specific paper elements for which they desire to improve recognition.