Factory Flow Benchmarking Report

The Lean Aircraft Initiative benchmarked representative part fabrications and some assembly operations within its member companies of the defense aircraft industry. This paper reports the results of this benchmarking effort. Comparisons are made using an efficiency metric called flow efficiency. Flow efficiency is defined as the ratio of the fabrication time to the cycle time. In addition, this report explores the major components of the cycle time: fabrication time, lot process delay, storage delay, and transportation delay. The report concludes that the major portion of the cycle time in this industry is storage delay and points out the opportunity to improve cycle time drastically by reducing the amount of storage delay being experienced in the fabrication of products

Lean Implementation Considerations in Factory Operations of Low Volume/High Complexity Production Systems

The researchers of the Lean Aircraft Initiative developed a hypothesized lean implementation model seeking to provide its members guidance on implementing lean transitions in factory operations of low volume/high complexity production systems. The model features four phases: (1) building a lean infrastructure to support lean behavior, (2) redesigning the flow of products in the factory, (3) revamping the operations management and (4) fostering process improvement. An order of implementation is discussed and each phase has implementation steps as well. Following the development of the hypothesized lean implementation model, twelve case studies were used to test the model. This report details the model and analyzes the case studies using the model as a framework

Integral Projection Models for host-parasite systems with an application to amphibian chytrid fungus

1. Host–parasite models are typically constructed under either a microparasite or macroparasite paradigm. However, this has long been recognized as a false dichotomy because many infectious disease agents, including most fungal pathogens, have attributes of both microparasites and macroparasites. 2. We illustrate how Integral Projection Models (IPMs) provide a novel modelling framework to represent both types of pathogens. We build a simple host–parasite IPM that tracks both the number of susceptible and infected hosts and the distribution of parasite burdens in infected hosts. 3. The vital rate functions necessary to build IPMs for disease dynamics share many commonalities with classic micro and macroparasite models and we discuss how these functions can be parameterized to build a host–parasite IPM. We illustrate the utility of this IPM approach by modelling the temperature-dependent epizootic dynamics of amphibian chytrid fungus in Mountain yellow-legged frogs (Rana muscosa). 4. The host–parasite IPM can be applied to other diseases such as facial tumour disease in Tasmanian devils and white-nose syndrome in bats. Moreover, the host–parasite IPM can be easily extended to capture more complex disease dynamics and provides an exciting new frontier in modelling wildlife disease.Full Tex

Spatial distribution of insecticide resistant populations of Aedes aegypti and Ae. albopictus and first detection of V410L mutation in Ae. aegypti from Cameroon

Background: Dengue (DENV), chikungunya (CHIKV) and Zika virus (ZIKV), are mosquito-borne viruses of medical importance in most tropical and subtropical regions. Vector control, primarily through insecticides, remains the primary method to prevent their transmission. Here, we evaluated insecticide resistance profiles and identified important underlying resistance mechanisms in populations of Aedes aegypti and Ae. albopictus from six different regions in Cameroon to pesticides commonly used during military and civilian public health vector control operations. Methods: Aedes mosquitoes were sampled as larvae or pupae between August 2020 and July 2021 in six locations across Cameroon and reared until the next generation, G1. Ae. aegypti and Ae. albopictus adults from G1 were tested following World Health Organization (WHO) recommendations and Ae. aegypti G0 adults screened with real time melting curve qPCR analyses to genotype the F1534C, V1016I and V410L Aedes kdr mutations. Piperonyl butoxide (PBO) assays and real time qPCR were carried out from some cytochrome p450 genes known to be involved in metabolic resistance. Statistical analyses were performed using Chi-square test and generalized linear models. Results: Loss of susceptibility was observed to all insecticides tested. Mortality rates from tests with 0.25% permethrin varied from 24.27 to 85.89% in Ae. aegypti and from 17.35% to 68.08% in Ae. albopictus. Mortality rates for 0.03% deltamethrin were between 23.30% and 88.20% in Ae. aegypti and between 69.47 and 84.11% in Ae. albopictus. We found a moderate level of resistance against bendiocarb, with mortality rates ranging from 69.31% to 90.26% in Ae. aegypti and from 86.75 to 98.95% in Ae. albopictus. With PBO pre-exposure, we found partial or fully restored susceptibility to pyrethroids and bendiocarb. The genes Cyp9M6F88/87 and Cyp9J10 were overexpressed in Ae. aegypti populations from Douala sites resistant to permethrin and deltamethrin. Cyp6P12 was highly expressed in alphacypermethrin and permethrin resistant Ae. albopictus samples. F1534C and V1016I mutations were detected in A. aegypti mosquitoes and for the first time V410L was reported in Cameroon. Conclusions: This study revealed that Ae. aegypti and Ae. albopictus are resistant to multiple insecticide classes with multiple resistance mechanisms implicated. These findings could guide insecticide use to control arbovirus vectors in Cameroon

Lean manufacturing principles : a comprehensive framework for improving production efficiency

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997.Includes bibliographical references (p. 122-125).by Auston Marmaduke Kilpatrick.M.S

Higher fat stores contribute to persistence of little brown bat populations with white‐nose syndrome

The persistence of populations declining from novel stressors depends, in part, on their ability to respond by trait change via evolution or plasticity. White‐nose syndrome (WNS ) has caused rapid declines in several North America bat species by disrupting hibernation behaviour, leading to body fat depletion and starvation. However, some populations of Myotis lucifugus now persist with WNS by unknown mechanisms. We examined whether persistence of M. lucifigus with WNS could be explained by increased body fat in early winter, which would allow bats to tolerate the increased energetic costs associated with WNS . We also investigated whether bats were escaping infection or resistant to infection as an alternative mechanism explaining persistence. We measured body fat in early and late winter during initial WNS invasion and 8 years later at six sites where bats are now persisting. We also measured infection prevalence and intensity in persisting populations. Infection prevalence was not significantly lower than observed in declining populations. However, at two sites, infection loads were lower than observed in declining populations. Body fat in early winter was significantly higher in four of the six persisting populations than during WNS invasion. Physiological models of energy use indicated that these higher fat stores could reduce WNS mortality by 58%–70%. These results suggest that differences in fat storage and infection dynamics have reduced the impacts of WNS in many populations. Increases in body fat provide a potential mechanism for management intervention to help conserve bat populations

Efficacy of a probiotic bacterium to treat bats affected by the disease white‐nose syndrome

The management of infectious diseases is an important conservation concern for a growing number of wildlife species. However, effective disease control in wildlife is challenging because feasible management options are often lacking. White‐nose syndrome (WNS ) is an infectious disease of hibernating bats that currently threatens several North American species with extinction. Currently, no effective treatments exist for WNS . We conducted a laboratory experiment to test the efficacy of probiotic treatment with Pseudomonas fluorescens , a bacterium that naturally occurs on bats, to reduce disease severity and improve survival of little brown bats Myotis lucifugus exposed to Pseudogymnoascus destructans , the fungal pathogen that causes WNS . We found that application of the probiotic bacteria at the time of fungal infection reduced several measures of disease severity and increased survival, whereas bacterial treatment prior to pathogen exposure had no effect on survival and worsened disease severity. Synthesis and applications . Our results suggest that probiotic treatment with Ps. fluorescens has potential for white‐nose syndrome disease management, but the timing of application is critical and should coincide with natural exposure of bats to P. destructans . These results add to the growing knowledge of how natural host microbiota can be implemented as a biocontrol treatment to influence disease outcomes

A method for campus-wide SARS-CoV-2 surveillance at a large public university

The systematic screening of asymptomatic and pre-symptomatic individuals is a powerful tool for controlling community transmission of infectious disease on college campuses. Faced with a paucity of testing in the beginning of the COVID-19 pandemic, many universities developed molecular diagnostic laboratories focused on SARS-CoV-2 diagnostic testing on campus and in their broader communities. We established the UC Santa Cruz Molecular Diagnostic Lab in early April 2020 and began testing clinical samples just five weeks later. Using a clinically-validated laboratory developed test (LDT) that avoided supply chain constraints, an automated sample pooling and processing workflow, and a custom laboratory information management system (LIMS), we expanded testing from a handful of clinical samples per day to thousands per day with the testing capacity to screen our entire campus population twice per week. In this report we describe the technical, logistical, and regulatory processes that enabled our pop-up lab to scale testing and reporting capacity to thousands of tests per day