Testing a Partial Ordering of Population Means with Application to Inference about Growth Habits of Cowpea Genotypes

Using general results available in the literature, we derive the likelihood ratio test for a particular partial ordering of means that naturally arises in a biological context. We then show that the conceptual and computational complexity of the derivation can be substantially reduced by equivalently deriving the test using the intersection-union principle for decomposing a complex null hypothesis into elemental forms. A Monte Carlo algorithm for obtaining the p-value of the test is proposed. The test procedure is illustrated with a data set of the competitive ability of several cowpea genotypes, where previous experiments have indicated the proposed partial order of the means. A simulation study is used to examine the power of the test.     

Incidentally discovered adrenal tumors: a lesson from observation of 1,444 patients

This study was aimed at summarizing our experience in the management of 1,444 patients with incidentally found adrenal tumors observed at a single endocrinological centre. Hormonal determinations were performed in all patients at the beginning of the observation period to detect subclinical adrenal hyperfunction. The imaging phenotype on CT and MRI was analyzed for defining the malignant potential of the tumors. Based on the results of these examinations we diagnosed among our cohort probably benign masses in 87%, malignant tumors in 10% (adrenal carcinoma - 9%), and metastases in 3%. Subclinical hyperfunction was diagnosed in 8%; the most frequent was the pre-Cushing's syndrome. A subgroup of 480 patients (33%) was submitted to surgery because of oncological or endocrinological indications. The patients not qualified for surgery were carefully controlled by imaging and hormonal examinations. Malignancy is the most serious risk in the group of patients with incidentally discovered adrenal tumors.     

A versatile transreplication-based system to identify cellular proteins involved in geminivirus replication

A versatile green fluorescent protein (GFP) expression cassette containing the replication origins of the monopartite begomovirus Tomato yellow leaf curl Sardinia virus (TYLCSV) is described. Transgenic Nicotiana benthamiana plants containing one copy of the cassette stably integrated into their genome were superinfected with TYLCSV, which mobilized and replicated the cassette as an episomal replicon. The expression of the reporter gene (the GFP gene) was thereby modified. Whereas GFP fluorescence was dimmed in the intercostal areas, an increase of green fluorescence in veins of all leaves placed above the inoculation site, as well as in transport tissues of roots and stems, was observed. The release of episomal trans replicons from the transgene and the increase in GFP expression were dependent on the cognate geminiviral replication-associated protein (Rep) and required interaction between Rep and the intergenic region of TYLCSV. This expression system is able to monitor the replication status of TYLCSV in plants, as induction of GFP expression is only produced in those tissues where Rep is present. To further confirm this notion, the expression of a host factor required for geminivirus replication, the proliferating cellular nuclear antigen (PCNA) was transiently silenced. Inhibition of PCNA prevented GFP induction in veins and reduced viral DNA. We propose that these plants could be widely used to easily identify host factors required for geminivirus replication by virus-induced gene silencing.     

Extracts of black and brown rice powders improve hepatic lipid accumulation via the activation of PPARα in obese and diabetic model mice

Rice powder extract (RPE) from black and brown rice (Oryza sativa L. indica) improves hepatic lipid accumulation in obese and diabetic model mice via peroxisomal fatty acid oxidation. RPE showed PPARα agonistic activity which did not differ between black and brown RPE despite a higher anthocyanin content in black RPE.     

DNA forms indicate rolling circle and recombination-dependent replication of Abutilon mosaic virus.

Geminiviruses have spread worldwide and have become increasingly important in crop plants during recent decades. Recombination among geminiviruses was one major source of new variants. Geminiviruses replicate via rolling circles, confirmed here by electron microscopic visualization and two-dimensional gel analysis of Abutilon mosaic virus (AbMV) DNA. However, only a minority of DNA intermediates are consistent with this model. The majority are compatible with recombination-dependent replication (RDR). During development of naturally infected leaves, viral intermediates compatible with both models appeared simultaneously, whereas agro-infection of leaf discs with AbMV led to an early appearance of RDR forms but no RCR intermediates. Inactivation of viral genes ac2 and ac3 delayed replication, but produced the same DNA types as after wild-type infection, indicating that these genes were not essential for RDR in leaf discs. In conclusion, host factors alone or in combination with the viral AC1 protein are necessary and sufficient for the production of RDR intermediates. The consequences of an inherent geminiviral recombination activity for the use of pathogen-derived resistance traits are discussed.