Discovery of the Cadmium Isotopes

Thirty-seven cadmium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.Comment: to be published in Atomic Data and Nuclear Data Table

Statistical methods for assays with limits of detection: Serum bile acid as a differentiator between patients with normal colons, adenomas, and colorectal cancer

In analytic chemistry a detection limit (DL) is the lowest measurable amount of an analyte that can be distinguished from a blank; many biomedical measurement technologies exhibit this property. From a statistical perspective, these data present inferential challenges because instead of precise measures, one only has information that the value is somewhere between 0 and the DL (below detection limit, BDL). Substitution of BDL values, with 0 or the DL can lead to biased parameter estimates and a loss of statistical power. Statistical methods that make adjustments when dealing with these types of data, often called left-censored data, are available in many commercial statistical packages. Despite this availability, the use of these methods is still not widespread in biomedical literature. We have reviewed the statistical approaches of dealing with BDL values, and used simulations to examine the performance of the commonly used substitution methods and the most widely available statistical methods. We have illustrated these methods using a study undertaken at the Vanderbilt-Ingram Cancer Center, to examine the serum bile acid levels in patients with colorectal cancer and adenoma. We have found that the modern methods for BDL values identify disease-related differences that are often missed, with statistically naive approaches

Quantitative analytical tools for bee health (Apis mellifera) assessment

Background: The number of honeybee (Apis mellifera) colony losses has grown significantly in the past decade, endangering pollination of agricultural crops. Research indicates that no single factor is sufficient to explain colony losses and that a combination of stressors appears to impact hive health. Accurate evaluation of the different factors such as pathogen load, environmental conditions, nutrition and foraging is important to understanding colony loss. Commonly used colony assessment methods are subjective and imprecise making it difficult to compare bee hive parameters between studies. Finding robust, validated methods to assess bees and hive health has become a key area of focus for bee health and bee risk assessment.Results: Our study focused on developing and implementing quantitative analytical tools that allowed us to investigate different factors contribution to colony loss. These validated methods include: adult bee and brood cell imaging and automated counting (IndiCounter, WSC Regexperts), cellular transmitting scales and weather monitoring (Phytech, ILS) and pathogen detection (QuantiGene® Plex 2.0 RNA assay platform from Affymetrix). These techniques enable accurate assessment of colony state.Conclusion: A major challenge to date for bee health is to identify the events leading to colony loss. Our study describes validated molecular and computational tools to assess colony health that can prospectively describe the etiology of potential diseases and in some cases identify the cause leading to colony collapse.Keywords: colony loss, colony assessment methods, cellular transmitting scales, weather monitoring, QuantiGene® Plex 2.0

Quantitative analytical tools for bee health (Apis mellifera) assessment

Background: The number of honeybee (Apis mellifera) colony losses has grown significantly in the past decade, endangering pollination of agricultural crops. Research indicates that no single factor is sufficient to explain colony losses and that a combination of stressors appears to impact hive health. Accurate evaluation of the different factors such as pathogen load, environmental conditions, nutrition and foraging is important to understanding colony loss. Commonly used colony assessment methods are subjective and imprecise making it difficult to compare bee hive parameters between studies. Finding robust, validated methods to assess bees and hive health has become a key area of focus for bee health and bee risk assessment. Results: Our study focused on developing and implementing quantitative analytical tools that allowed us to investigate different factors contribution to colony loss. These validated methods include: adult bee and brood cell imaging and automated counting (IndiCounter, WSC Regexperts), cellular transmitting scales and weather monitoring (Phytech, ILS) and pathogen detection (QuantiGene® Plex 2.0 RNA assay platform from Affymetrix). These techniques enable accurate assessment of colony state. Conclusion: A major challenge to date for bee health is to identify the events leading to colony loss. Our study describes validated molecular and computational tools to assess colony health that can prospectively describe the etiology of potential diseases and in some cases identify the cause leading to colony collapse

On the construction of split-face topologies

We give a general theorem to facilitate the construction of interesting examples of split-face topologies of compact, convex sets.</p