Ureteric complications and left retroperitoneal abdominal aortic surgery.

BACKGROUND: Open surgery for abdominal aortic aneurysms in the UK is usually performed via a midline transperitoneal incision. However, the left retroperitoneal (RP) approach may be beneficial for juxtarenal abdominal aortic aneurysms and certain physiological reasons. One potential disadvantage is that the left kidney usually requires mobilization anteromedially risking injury to the renal tract and possibly the ureter. METHODS: In this retrospective study, the time of onset, clinical presentation and treatment of left renal tract complications are scrutinized and discussed. Reasons for open aortic surgery as opposed to endovascular repair being undertaken were documented. Also, the aortic cross-clamp positions and type of reconstruction were examined. RESULTS: A total of 208 patients underwent RP aortic surgery for aneurysmal disease. The aortic cross-clamp positions were infrarenal in 115 (55%), suprarenal in 78 (38%) and supra-superior mesenteric artery or supracoeliac in 15 (7%). Two percent (4/208) sustained ureteric complications and all occurred in the upper third of the left ureter. The time of onset of symptoms ranged from 2 to 14 days post-operatively with a median of 3.5. Clinical signs were non-specific including pyrexia, tachycardia and flank pain. CONCLUSION: Ureteric complications following left RP aortic surgery is uncommon and usually occurs in the upper third of the renal tract. Trauma appears to be the most common cause, although ureteric ischaemia can occur but presents later particularly in those with comorbidities.

Herbarium specimens reveal substantial and unexpected variation in phenological sensitivity across the eastern United States.

Phenology is a key biological trait that can determine an organism's survival and provides one of the clearest indicators of the effects of recent climatic change. Long time-series observations of plant phenology collected at continental scales could clarify latitudinal and regional patterns of plant responses and illuminate drivers of that variation, but few such datasets exist. Here, we use the web tool CrowdCurio to crowdsource phenological data from over 7000 herbarium specimens representing 30 diverse flowering plant species distributed across the eastern United States. Our results, spanning 120 years and generated from over 2000 crowdsourcers, illustrate numerous aspects of continental-scale plant reproductive phenology. First, they support prior studies that found plant reproductive phenology significantly advances in response to warming, especially for early-flowering species. Second, they reveal that fruiting in populations from warmer, lower latitudes is significantly more phenologically sensitive to temperature than that for populations from colder, higher-latitude regions. Last, we found that variation in phenological sensitivities to climate within species between regions was of similar magnitude to variation between species. Overall, our results suggest that phenological responses to anthropogenic climate change will be heterogeneous within communities and across regions, with large amounts of regional variability driven by local adaptation, phenotypic plasticity and differences in species assemblages. As millions of imaged herbarium specimens become available online, they will play an increasingly critical role in revealing large-scale patterns within assemblages and across continents that ultimately can improve forecasts of the impacts of climatic change on the structure and function of ecosystems.This article is part of the theme issue 'Biological collections for understanding biodiversity in the Anthropocene'.

CrowdCurio: an online crowdsourcing platform to facilitate climate change studies using herbarium specimens.

Phenology is a key aspect of plant success. Recent research has demonstrated that herbarium specimens can provide important information on plant phenology. Massive digitization efforts have the potential to greatly expand herbarium-based phenological research, but also pose a serious challenge regarding efficient data collection. Here, we introduce CrowdCurio, a crowdsourcing tool for the collection of phenological data from herbarium specimens. We test its utility by having workers collect phenological data (number of flower buds, open flowers and fruits) from specimens of two common New England (USA) species: Chelidonium majus and Vaccinium angustifolium. We assess the reliability of using nonexpert workers (i.e. Amazon Mechanical Turk) against expert workers. We also use these data to estimate the phenological sensitivity to temperature for both species across multiple phenophases. We found no difference in the data quality of nonexperts and experts. Nonexperts, however, were a more efficient way of collecting more data at lower cost. We also found that phenological sensitivity varied across both species and phenophases. Our study demonstrates the utility of CrowdCurio as a crowdsourcing tool for the collection of phenological data from herbarium specimens. Furthermore, our results highlight the insight gained from collecting large amounts of phenological data to estimate multiple phenophases.

Improving Retrieval Efficacy of Homology Searches Using the False Discovery Rate.

Over the past few decades, discovery based on sequence homology has become a widely accepted practice. Consequently, comparative accuracy of retrieval algorithms (e.g., BLAST) has been rigorously studied for improvement. Unlike most components of retrieval algorithms, the E-value threshold criterion has yet to be thoroughly investigated. An investigation of the threshold is important as it exclusively dictates which sequences are declared relevant and irrelevant. In this paper, we introduce the false discovery rate (FDR) statistic as a replacement for the uniform threshold criterion in order to improve efficacy in retrieval systems. Using NCBI's BLAST and PSI-BLAST software packages, we demonstrate the applicability of such a replacement in both non-iterative (BLASTFDR) and iterative (PSI-BLAST(FDR)) homology searches. For each application, we performed an evaluation of retrieval efficacy with five different multiple testing methods on a large training database. For each algorithm, we choose the best performing method, Benjamini-Hochberg, as the default statistic. As measured by the threshold average precision, BLAST(FDR) yielded 14.1 percent better retrieval performance than BLAST on a large (5,161 queries) test database and PSI-BLAST(FDR) attained 11.8 percent better retrieval performance than PSI-BLAST. The C++ source code specific to BLAST(FDR) and PSI-BLAST(FDR) and instructions are available at http://www.cs.mtsu.edu/~hcarroll/blast_fdr/.