477 research outputs found

    Localized JNK signaling regulates organ size during development.

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    A fundamental question of biology is what determines organ size. Despite demonstrations that factors within organs determine their sizes, intrinsic size control mechanisms remain elusive. Here we show that Drosophila wing size is regulated by JNK signaling during development. JNK is active in a stripe along the center of developing wings, and modulating JNK signaling within this stripe changes organ size. This JNK stripe influences proliferation in a non-canonical, Jun-independent manner by inhibiting the Hippo pathway. Localized JNK activity is established by Hedgehog signaling, where Ci elevates dTRAF1 expression. As the dTRAF1 homolog, TRAF4, is amplified in numerous cancers, these findings provide a new mechanism for how the Hedgehog pathway could contribute to tumorigenesis, and, more importantly, provides a new strategy for cancer therapies. Finally, modulation of JNK signaling centers in developing antennae and legs changes their sizes, suggesting a more generalizable role for JNK signaling in developmental organ size control

    A Model for Introducing the Spiritual Disciplines to the Members of the Capital Memorial Seventh-day Adventist Church

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    This dissertation project developed out of the researcher\u27s own spiritual pilgrimage in a search for greater intimacy with God. An introduction to the ancient spiritual disciplines provided the means for that intimacy to develop and, subsequently, created a desire to share the disciplines in ministry with members of his congregation. A model was envisaged which could become a life-changing event in the life of the individual member. The development and use of this model was the subject of the project. The model includes an introduction to four basic disciplines: prayer, the devotional use of Scripture, meditation, and journaling. For each discipline, there is also a careful outline presented as to how the discipline may be practiced successfully. A retreat setting, which proved to be very successful, was selected for using the model for the first time. This entire process is carefully described and evaluated in the report with a recommendation that further retreats include more time and that a follow-up plan be in place well in advance. Included in the project was research into the spiritual formation process— with emphasis on the disciplines, its historical development, its place in Seventh-day Adventist theology, and how it was viewed by Ellen White, one of Adventism\u27s founders. The results from this research were included in the model to provide a background legitimacy for the disciplines as they were introduced. It was discovered that Adventist theologians have had much to say about the holiness God requires from those who are saved, but little practical advice as to how it occurs. In fact, there has been a debate over the years about faith and works with no apparent conclusion. There was convincing evidence, however, that Ellen White understood the spiritual formation process and knew the importance of the spiritual disciplines. Her extensive writing on the subject provided valuable affirmation for the model. Survey and evaluation instruments were created to determine the need for using the model and for its effectiveness. The survey results which are reported in the dissertation, confirm the need for assistance in developing intimacy with God among those who responded. Those who participated in the first use of the model gave a high effectiveness rating, although it was apparent that some adjustments would be helpful in order to reinforce the changes which would be required to develop the desired intimacy with God

    Made for Walking

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    Developing an Enhanced Forest Inventory in Maine Using Airborne Laser Scanning: The Role of Calibration Plot Design and Data Quality

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    Forests provide essential ecosystem services such as carbon sequestration, clean water, lumber, and more. It is important that foresters be able to collect accurate forest inventories, especially in a changing climate. Foresters need to know what is in the forest not only to manage for the economic benefits, but also to manage for social acceptability and ecological soundness to prevent further degradation of these ecosystem services. One way to collect accurate and precise forest inventories is through the utilization of remote sensing products. These enhanced forest inventories (EFIs) can be done at varying resolutions that are contingent on the plot design creating wall-to-wall raster data and thus, complete spatial knowledge of these estimates can be determined. A popular remote sensing product to be used to create EFIs is airborne laser scanning (ALS). Although best practices guides have been created in other countries, research on the best plot type and design has not been done for Maine’ structurally diverse and intensively managed forests. The goal of this study was to investigate a range of forest designs to determine the best ground-based calibration plot specifications for developing EFI models from ALS data in Maine. We developed a model that compared fixed versus variable radius plots, sampling size and intensity, and sample design with ALS data to map EFI variables like percent softwood, volume, BA, and tree count. Data were collected from the Penobscot Experimental Forest (PEF) in summer 2022 that had two different plot types, two sample sizes and sampling intensities, and two different sample designs. Data from other study sites were provided to us from our partners that only included one plot type, sample size and intensity, and sample design each. For validation, we used data collected in the Demeritt Forest also in summer 2022. We assessed R2, root mean square error (RMSE), coefficient of variation (CV), and mean bias for models with varying forest inventory designs to establish the best calibration plot for ALS in our study areas. It was determined that a principal component analysis for plot placement gave better model results than randomly placed plots. Also, fixed radius plots (FRPs) and a smaller sample size generated better evaluation statistics when predicting percent softwood, volume, and tree count in the PEF. In contrast, VRPs with a smaller sample size provided better model outcomes when predicting basal area (BA). Once the best forest inventory calibration plot design was identified and validated, we applied it to the PEF to estimate aboveground biomass. Although there were obvious trends in our results, there is still more research to be done to ensure that our potential recommendations are correct. It seems that there was better model performance in spruce-fir forest types than other forest types like oak-pine. Our results provide insights on an optimal approach for specific conditions and underscore the importance of future research to assist decision-making on plot type and sample design for the broad range of conditions on forested landscapes in Maine

    Detection Of The Lung Environment By Multi-Drug Resistant Gram-Negative Bacterial Pathogens

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    Nosocomial lung infections are a growing concern in the United States, with more than 300,000 cases reported annually. More than 30 % of which are caused by the Gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae. Similarly, Gram-negative bacteria establish chronic infections in individuals with cystic fibrosis (CF) that are difficult or impossible to eradicate.P. aeruginosa has historically been one of the most prevalent pathogens of adults with CF. However, as antipseudomonal therapy has improved, more antibiotic resistant species have taken hold, including Stenotrophomonas maltophilia, which now colonizes more than 10 % of individuals with CF. Regardless of the cause or source, Gram-negative respiratory infections are becoming increasingly difficult to treat due to the rising incidence of multiple drug resistance among these organisms. To aid in the development of new therapeutics, a greater understanding of how these organisms transition from the environment to the host lung is needed. Here we utilized a combination of transcriptomics and molecular genetics to examine how P. aeruginosa, K. pneumoniae, and S. maltophilia, recognize and exploit the host lung milieu during the initiation of infection. One of the first components of the host lung environment that aspirated bacteria are exposed to is pulmonary surfactant (PS). This phospholipid-rich substance coats the distal airways of the lung and is thought to contain molecular cues that facilitate lung colonization by pathogenic bacteria. Here, we characterized the transcriptional response of K. pneumoniae to purified PS to examine how this organism interreacts with the host lung during colonization. This work revealed numerous virulence and colonization-related genes that are expressed by K. pneumoniae under these conditions. We also tested the contribution of other surfactant-induced transcripts to K. pneumoniae pathogenesis using engineered gene deletion strains and a mouse model of pneumonia. This work revealed the polyamine efflux pump, MdtJI, and glycine betaine transporter, ProU are required for K. pneumoniae virulence. Phosphatidylcholine is the primary constituent of PS. P. aeruginosa is capable of completely metabolizing the phosphocholine head group of this lipid, and readily does so when exposed to PS. We previously observed that the most highly expressed genes in P. aeruginosa in response to PS were those involved in the catabolism of a downstream choline metabolite, sarcosine. Although our group had previously characterized the choline catabolic pathway of P. aeruginosa, the transcriptional regulation of sarcosine catabolism was not known. We utilized a genetic screen to identify the regulator controlling the expression of the sarcosine catabolic genes in P. aeruginosa. This regulator, which we named SouR (Sarcosine oxidase utilization Regulator) is the first sarcosine-responsive regulator to be characterized. The thick, viscous mucus (sputum) that accumulates within the CF lung serves as the primary nutrient source for microbes colonizing the CF lung. Here, we characterized the transcriptional responses of three S. maltophilia strains during growth in synthetic CF sputum media (SCFM2) to gain insight into how this organism interreacts with the host lung. We also compared the SCFM2 transcriptomes of two S. maltophilia CF isolates with the SCFM2 transcriptome of the acute infection model strain, K279A. This revealed CF isolate-specific signatures in gene expression that reflect adaptation to the CF lung

    The Deep Seabed Hard Mineral Resources Act and the Third United Nations Conference on the Law of the Sea: Can the Conference Meet the Mandate Embodied in the Act

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    This Comment analyzes the composition and decision-making procedures of the proposed International Seabed Authority with respect to access to the seabed, security of tenure for U.S. citizens who begin exploration for, or commercial recovery of, minerals before the Law of the Sea Treaty enters into force, and the economic feasibility of seabed mining under the proposed treaty in an effort to determine the treaty\u27s acceptability to the United States. The author argues that the structure of the Draft Convention is aimed more towards global interests, rather than those of the United States, and this fact will pose a potential problem to the ratification of the treaty by the U.S. Senate, but that the Draft Convention has the potential to adequately serve the mandates articulated in the Deep Seabed Hard Mineral Resources Act

    Impacts of Health Habits through Fit5

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    PURPOSE: The Fit5 program was developed by the Special Olympics to help individuals with developmental disabilities make improvements in their health and fitness. The purpose of this study was to examine whether a 6 week program using the Fit5 resource could result in improvements in the physical activity and diet of ten adults with developmental disabilities. METHODS: The individuals were taken through a six-week program where for 45 minutes each week they would exercise according to the Fit5 information that they were provided. During each session, instructors would briefly talk about their diet. At the beginning and end of the process, everyone filled out a questionnaire regarding their habits when it comes to exercise and their diet. Responses from multiple-choice questions were coded for statistical analysis. For numerical answer choices, the code was synonymous. For example, eating 1-2 fruits a day was coded as a 2. For responses that were categorical, the preferred choice was coded with a higher score. For example, for the frequency of snack food intake, daily was scored as 0 and never was scored as 3 . RESULTS: There were two categories that had a significant difference in the pre and post-program data. The biggest decrease in unhealthy behavior was the amount of time spent watching TV and playing video games followed by the amount of snack food consumed. The average hours of tv and video games per day was 3 hours per day before Fit5 and 1.8 hours per day after Fit5 making the T-value less than .001. The frequency of consuming snack food the average score was .3 before Fit5 and 1.1 after Fit5 which represents a shift from weekly to monthly consumption of snack foods, the T-value is less than 0.05. There were also two points that were close to being significant, sugary drinks and vegetable consumption. Sugary drinks originally scored at 0.3 at the start of Fit5 to scoring a 0.8 at the end of Fit5showing a shift from having these drinks daily to almost weekly to daily having a t value of 0.051. The number of vegetables consumed went from or scoring a 0.9 at the start of Fit5, meaning only having one vegetable a day, to scoring a 1.4 at the end of Fit5, the conception of 2-3 vegetables a day, day, with a T-value of 0.069. CONCLUSION: The hypothesis is supported by the survey results, as we do see an improvement in some of the habits. While there wasn’t a substantial improvement in the data, with this being a small group consisting of only ten individuals, and this study focused on getting these individuals to exercise, this data is still promising. The program was designed to briefly talk about diet before starting the focus of the program, encouraging exercise. If we could focus more time on healthy diet and lifestyle portions and provide more material, it is likely that we would see more significant difference data points

    Work Analysis with Resource-Aware Session Types

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    While there exist several successful techniques for supporting programmers in deriving static resource bounds for sequential code, analyzing the resource usage of message-passing concurrent processes poses additional challenges. To meet these challenges, this article presents an analysis for statically deriving worst-case bounds on the total work performed by message-passing processes. To decompose interacting processes into components that can be analyzed in isolation, the analysis is based on novel resource-aware session types, which describe protocols and resource contracts for inter-process communication. A key innovation is that both messages and processes carry potential to share and amortize cost while communicating. To symbolically express resource usage in a setting without static data structures and intrinsic sizes, resource contracts describe bounds that are functions of interactions between processes. Resource-aware session types combine standard binary session types and type-based amortized resource analysis in a linear type system. This type system is formulated for a core session-type calculus of the language SILL and proved sound with respect to a multiset-based operational cost semantics that tracks the total number of messages that are exchanged in a system. The effectiveness of the analysis is demonstrated by analyzing standard examples from amortized analysis and the literature on session types and by a comparative performance analysis of different concurrent programs implementing the same interface.Comment: 25 pages, 2 pages of references, 11 pages of appendix, Accepted at LICS 201

    Quasi-Orthogonal Wideband Radar Waveforms Based on Chaotic Systems

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    Many radar applications, such as those involving multiple-input, multiple-output (MIMO) radar, require sets of waveforms that are orthogonal, or nearly orthogonal. As shown in the work presented here, a set of nearly orthogonal waveforms with a high cardinality can be generated using chaotic systems, and this set performs comparably to other waveform sets used in pulse compression radar systems. Specifically, the nearly orthogonal waveforms from chaotic systems are shown to possess many desirable radar properties including a compact spectrum, low range sidelobes, and an average transmit power within a few dB of peak power. Moreover, these waveforms can be generated at essentially any practical time length and bandwidth. Since these waveforms are generated from a deterministic process, each waveform can be represented with a small number of system parameters. Additionally, assuming these waveforms possess a large time-bandwidth product, a high number of nearly orthogonal chaotic waveforms exist for a given time and bandwidth. Thus the proposed generation procedure can potentially be used to generate a new transmit waveform on each pulse.United States. Air Force (Contract FA8721-05-C-0002)Massachusetts Institute of Technology. Research Laboratory of ElectronicsBAE SystemsTexas Instruments Incorporated. Leadership University Consortium Progra
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