Predicting Mountain Pine Beetle Development with the Extended von Foerster Model

The mountain pine beetle (Dendroctonus ponderosae Hopkins) represents a significant threat to ponderosa pine and lodgepole pine stands in the western United States, and has the potential to threaten commercially valuable jack pine in both the United States and Canada. The success of the mountain pine beetle is based on synchronization of developmental events to time cold-hardened life stages for extreme winter temperatures and to facilitate mass attack and overwhelm the defenses of the host. This paper presents a solution methodology for an extended McKendrick - von Foerster model for the development of the mountain pine beetle in varying temperature environments. The model reflects the effect of phenotypic variability on output, and is suitable for determining field distributions of emergence events. An efficient computational method, based on Green\u27s functions, is presented. Results are compared with direct numerical simulation, and the modelling and simulation strategy is applied to determine the distribution of emergence for mountain pine beetles. Eventually these results will be applied to improve forest management strategies in regard to the epidemic outbreak of pine beetles in northwestern North America

Immunological Effects of Ketoconazole, Itraconazole and Fluconazole on Lymphocyte Cell Proliferation and Natural Killer Cell Activity in Immune-Normal, Cyclosporine-Compromised and Cyclophosphamide-Compromised Mouse Models

Over the past several years there has been a steady increase in the incidence of immunologically compromised patients. This has been the result of both chemical agents, such as those used in cancer chemotherapy, and biological agents such as HIV, the cause of Acquired lmmunodefeciency Syndrome (AIDS). The increase in immune-suppressed patients has lead to an increase in life-threatening mycoses requiring treatment with antifungal agents. Pharmaceutical companies have increased research for the development of new antifungal agents which are more effective and less toxic than those that are currently used. Several researchers have reported on antifungal agents that demonstrate both positive and negative effects on the immune system. Because antifungal therapy relies on host immune defenses in eliminating diseases, more emphasis is being placed on how antifungal agents interact with the immune system. The purpose of this study was to evaluate the effects of Ketoconazole, ltraconazole and Fluconazole on T- and B-cell proliferation and natural killer cell activity using normal, cyclosporine-compromised and cyclophosphamide-compromised immune models in mice. T and B cells obtained from the spleens Balb/c mice were mitogen stimulated and grown in the presence of 0, 1, 2, 4, 8 and 16 µg/ml of these 3 antifungal agents. Cell proliferation was determined by the uptake of 3[H]-thymidine and was measured as counts per minute. Natural killer cell activity was measured by the release of 51-sodium chromate (51Cr) into the supernatant by 51Cr-labeled Yac cells. Ketoconazole caused a significant reduction in cell proliferation in all immune models in both T and B cells. Itraconazole also significantly inhibited cell proliferation in all models in both T and B cells as well as natural killer (NK) cell activity in the immune-normal model. Viability studies on mitogen-stimulated lymphocytes suggest that inhibitory effects of Katoconazole and Itraconazole on lymphocyte proliferation are due to toxic effects. Fluconazole appears to have few if any inhibitory effects on either cell proliferation or natural killer cell activity

COSPAR Sample Safety Assessment Framework (SSAF)

The Committee on Space Research (COSPAR) Sample Safety Assessment Framework (SSAF) has been developed by a COSPAR appointed Working Group. The objective of the sample safety assessment would be to evaluate whether samples returned from Mars could be harmful for Earth's systems (e.g., environment, biosphere, geochemical cycles). During the Working Group's deliberations, it became clear that a comprehensive assessment to predict the effects of introducing life in new environments or ecologies is difficult and practically impossible, even for terrestrial life and certainly more so for unknown extraterrestrial life. To manage expectations, the scope of the SSAF was adjusted to evaluate only whether the presence of martian life can be excluded in samples returned from Mars. If the presence of martian life cannot be excluded, a Hold &amp; Critical Review must be established to evaluate the risk management measures and decide on the next steps. The SSAF starts from a positive hypothesis (there is martian life in the samples), which is complementary to the null-hypothesis (there is no martian life in the samples) typically used for science. Testing the positive hypothesis includes four elements: (1) Bayesian statistics, (2) subsampling strategy, (3) test sequence, and (4) decision criteria. The test sequence capability covers self-replicating and non-self-replicating biology and biologically active molecules. Most of the investigations associated with the SSAF would need to be carried out within biological containment. The SSAF is described in sufficient detail to support planning activities for a Sample Receiving Facility (SRF) and for preparing science announcements, while at the same time acknowledging that further work is required before a detailed Sample Safety Assessment Protocol (SSAP) can be developed. The three major open issues to be addressed to optimize and implement the SSAF are (1) setting a value for the level of assurance to effectively exclude the presence of martian life in the samples, (2) carrying out an analogue test program, and (3) acquiring relevant contamination knowledge from all Mars Sample Return (MSR) flight and ground elements. Although the SSAF was developed specifically for assessing samples from Mars in the context of the currently planned NASA-ESA MSR Campaign, this framework and the basic safety approach are applicable to any other Mars sample return mission concept, with minor adjustments in the execution part related to the specific nature of the samples to be returned. The SSAF is also considered a sound basis for other COSPAR Planetary Protection Category V, restricted Earth return missions beyond Mars. It is anticipated that the SSAF will be subject to future review by the various MSR stakeholders.</p

Surrogate variable analysis

Thesis (Ph. D.)--University of Washington, 2007.Modern high-throughput molecular biology experiments measure data for thousands of related features and seek to rank those features for association with some variables of experimental or clinical importance. The process of ranking features for association with primary variables is complicated by genetic, environmental, and technical factors that influence hundreds or thousands of features at a time. In highdimensional experiments these factors are often unknown, unmeasured, or incapable of being tractably modeled. Consistent patterns of variation across features due to unmeasured or unmodeled factors can confound the relationship between the primary variables and the measured features. In this thesis we provide a statistical framework for modeling large-scale noise dependence caused by unmeasured or unmodeled factors in high-throughput data. We argue that estimating the sources of noise dependence is more appropriate than estimating the pairwise covariance between all features when the number of features is large. A direct connection is made with the well-studied problem of multiple testing dependence, which typically focuses on the distribution of P-values from multiple testing procedures. We introduce the concept of surrogate variables, estimable linear combinations of the true unmeasured or unmodeled factors causing noise dependence, that can be included when modeling the relationship between the primary variables and the feature level data. We also propose algorithms for estimating surrogate variables based on principal component analysis of relevant subsets of features. Under certain conditions accounting for the estimated surrogate variables asymptotically corrects the ranking and error rate estimation in high-throughput data analysis. We also discuss pathological situations when surrogate variables can not be estimated. To illustrate the power of this approach, we apply our estimates of the surrogate variables to improve reproducibility in a large clinical gene expression study of trauma related outcomes

Recovery of lung function following a pulmonary exacerbation in patients with cystic fibrosis and the G551D-CFTR mutation treated with ivacaftor

Background: Pulmonary exacerbations (PEx) are associated with acute loss of lung function that is often not recovered after treatment. We investigated lung function recovery following PEx for ivacaftor- and placebo-treated subjects

Data from: Active background choice facilitates crypsis in a tropical crab

Animals can evade predators in multiple ways, one of the most effective of which is to avoid detection in the first place. We know much about the evolution of color patterns that match the visual background to avoid detection (i.e., crypsis), yet we know surprisingly less about the specific behaviors that have co-evolved with these morphological traits to enhance or maintain crypsis. We here explore whether the match between body color and background in a seemingly well-camouflaged tropical shore crab is a result of active background choice. Taking advantage of a coastal area in the Solomon Islands with variable sand color and a population of the pallid ghost crab Ocypode pallidula with varying carapace color, we experimentally tested whether individuals actively choose specific substrate that best matches their color patterns. We found that individuals taken from extreme sand colors chose substrate that maintained crypsis, with relatively darker crabs typically choosing dark sand and lighter crabs choosing light sand. Crabs of intermediate color pattern, in contrast, showed no clear preference for dark or light sand. Our results suggest that potential prey can actively choose specific backgrounds to enhance and maintain crypsis, providing insights into how behavior interacts with morphological traits to avoid predator detection

Active background choice facilitates crypsis in a tropical crab

Animals can evade predators in multiple ways, one of the most effective of which is to avoid detection in the first place. We know much about the evolution of color patterns that match the visual background to avoid detection (i.e., crypsis), yet we know surprisingly less about the specific behaviors that have co‐evolved with these morphological traits to enhance or maintain crypsis. We here explore whether the match between body color and background in a seemingly well‐camouflaged tropical shore crab is a result of active background choice. Taking advantage of a coastal area in the Solomon Islands with variable sand color and a population of the pallid ghost crab Ocypode pallidula with varying carapace color, we experimentally tested whether individuals actively choose specific substrate that best matches their color patterns. We found that individuals taken from extreme sand colors chose substrate that maintained crypsis, with relatively darker crabs typically choosing dark sand and lighter crabs choosing light sand. Crabs of intermediate color pattern, in contrast, showed no clear preference for dark or light sand. Our results suggest that potential prey can actively choose specific backgrounds to enhance and maintain crypsis, providing insights into how behavior interacts with morphological traits to avoid predator detection