Acoustic Modeling Of A Uas For Use In A Hostile Fire Detection System

Unmanned Aerial System (UAS) usage has continually increased in recent years for both recreational and military applications. One particular military application being researched is utilizing a UAS as a host platform for Hostile Fire Detection Systems (HFDS), with particular interest being focused on multi-rotor drone platforms. The type of HFDS considered in this work is based upon acoustic sensors. An acoustic based HFDS utilizes an array of microphones to measure acoustic data and then applies signal processing algorithms to determine if a transient signal is present and if present then estimates the direction from which the sound arrived. The main issue with employing an acoustic based HFDS on a multi-rotor drone is the high level of background noise due to motors, propellers, and flow noise. In this thesis a study of the acoustic near field, particularly relevant to microphones located on the drone, was performed to understand the noise produced by the UAS. More specifically, the causes and characteristics of the sources of noise were identified. The noise characteristics were then used to model the noise sources for multiple motor assemblies based upon position of the microphone and revolutions per minute (RPM) of the motors. Lastly, signal processing techniques were implemented to identify if transient signals are present and if present estimate the direction from which the sound arrives

The role of titin and nebulin in myofibril assembly in cultured embryonic chick muscle cells

The purpose of this study was to examine the role of the two high molecular weight proteins, titin and nebulin, in skeletal muscle myofibrillogenesis. A monoclonal antibody against chicken breast titin was produced, and used in conjunction with polyclonal antibodies against chicken breast titin and nebulin, and monoclonal antibodies to actin and muscle-specific myosin in a series of double-label immunofluorescence studies to examine the organization of these proteins in cultured skeletal muscle cells derived from 12 day chick embryos. Postmitotic, mononucleated myoblasts synthesized titin, myosin, actin, and nebulin. Initial myofibril assembly events involved the coalescence of titin and myosin in a continuous pattern along actin containing structures morphologically similar to stress fibers. Titin and myosin organization into the skeletal muscle myofibril appeared to be coupled, as adult-like titin banding patterns were not observed in the absence of myosin organization into A bands. Titin and actin organization, in contrast, did not appear to be linked. Organization of titin into adult-like double bands along nascent myofibrils consistently preceded that of actin. Neither nebulin and myosin nor nebulin and titin assembly appeared to be linked, since the appearance of nebulin banding was seen after the formation of titin and myosin bands along nascent myofibrils. Nebulin organization occurred either at the same time or after the assembly of actin into I bands. A possible correlation between the formation of adult-like nebulin double bands and the appearance of phase-dense Z lines was noted, however. Labeling experiments were repeated with cultures exposed to the mutagenic alkylating agent ethyl methanesulfonate (EMS). The results of labeling experiments of EMS cells confirmed those found in the normal culture system. In conclusion, it appears that titin does not play a scaffolding or template role for subsequent thick filament alignment into A bands. The possibility of a template role for thin filament alignment into I bands can not be excluded, however, because titin organization precedes actin. The relationship between nebulin organization and the appearance of Z lines suggests that nebulin may be involved in Z line assembly or may regulate the insertion of thin filaments into Z lines

Thymosin-␤4 Inhibits Corneal Epithelial Cell Apoptosis after Ethanol Exposure In Vitro

PURPOSE. The purpose of this study was to determine the effect of thymosin beta 4 (T␤ 4 ) treatment on human corneal epithelial cells exposed to ethanol in vitro. The efficacy of T␤ 4 in preventing mitochondrial disruption and in inhibiting caspasemediated apoptosis was examined. METHODS. Nontransformed human corneal epithelial cells (HCECs) at passage 4 were untreated or treated with ethanol (20% for 20 seconds) or a combination of ethanol and T␤ 4 . The cells were allowed to recover from ethanol treatment for 24 hours. Mitochondrial membrane integrity and the release of cytochrome c to the cytoplasm were assessed using microscopy, Western blot, and ELISA. Bcl-2 expression and cell proliferation were measured using ELISA. Colorimetric activity assays were completed for caspase-2, -3, -8, and -9. RESULTS. T␤ 4 treatment decreased deleterious mitochondrial alterations, significantly decreased cytochrome c release from mitochondria, and increased Bcl-2 expression in ethanol-exposed human corneal epithelial cells. In ethanol-exposed corneal epithelium T␤ 4 treatment inhibited caspase-2, -3, -8, and -9 activity, with caspase-8 showing the most significant inhibition. T␤ 4 treatment resulted in no significant effect on the proliferation of human corneal epithelial cells after ethanol exposure. CONCLUSIONS. T␤ 4 plays an antiapoptotic role under conditions of epithelial cell challenge with an external stress such as exposure to ethanol. T␤ 4 may function as an antiapoptotic agent by inhibiting the release of cytochrome c from mitochondria and by suppressing the activation of caspases. (Invest Ophthalmol Vis Sci

Investigation of K14/K5 as a stem cell marker in the limbal region of the bovine cornea

Background: Identification of stem cells from a corneal epithelial cell population by specific molecular markers has been investigated previously. Expressions of P63, ABCG2 and K14/K5 have all been linked to mammalian corneal epithelial stem cells. Here we report on the limitations of K14/K5 as a limbal stem cell marker. Methodology/Principal Findings: K14/K5 expression was measured by immunohistochemistry, Western blotting and Real time PCR and compared between bovine epithelial cells in the limbus and central cornea. A functional study was also included to investigate changes in K5/14 expression within cultured limbal epithelial cells undergoing forced differentiation. K14 expression (or its partner K5) was detected in quiescent epithelial cells from both the limbal area and central cornea. K14 was localized predominantly to basal epithelial cells in the limbus and suprabasal epithelial cells in the central cornea. Western blotting revealed K14 expression in both limbus and central cornea (higher levels in the limbus). Similarly, quantitative real time PCR found K5, partner to K14, to be expressed in both the central cornea and limbus. Following forced differentiation in culture the limbal epithelial cells revealed an increase in K5/14 gene/protein expression levels in concert with a predictable rise in a known differentiation marker. Conclusions/Significance: K14 and its partner K5 are limited not only to the limbus but also to the central bovine cornea epithelial cells suggesting K14/K5 is not limbal specific in situ. Furthermore K14/K5 expression levels were not lowered (in fact they increased) within a limbal epithelial cell culture undergoing forced differentiation suggesting K14/K5 is an unreliable maker for undifferentiated cells ex vivo

Blood group antigens and integrins as biomarkers in head and neck cancer: Is aberrant tyrosine phosphorylation the cause of altered Α6Β4 integrin expression?

Head and neck cancer is a capricious disease that varies greatly in its clinical behavior. The development of biomarkers that can distinguish between biologically aggressive and indolent tumors has been a long term goal of our laboratories. Predictive markers applicable to biopsy specimens should facilitate clinical management through early identification of patients at greatest risk for early relapse or metastatic spread. Two prominent cell surface markers that we identified by raising monoclonal antibodies to squamous cell carcinomas are blood group antigens and the A9 antigen/Α6Β4 integrin. Both of these markers are abnormally displayed in squamous cancers of the head and neck and serve as indicators of early relapse. Loss of blood group antigen expression is a stronger single indicator than is overexpression of the Α6Β4 integrin. However, use of both markers together is a stronger predictive indicator than is either alone. We know little about the function of the blood group antigens in squamous cells except that the mature antigens are associated with differentiation. Similarly, the function of the Α6Β4 integrin is also not fully understood. Integrin Α6Β4 is thought to serve as an extracellular matrix receptor, but its ligand has not been confirmed. In resting epithelium, the Α6Β4 integrin is polarized to the basal aspect of the basal cell as a component of the hemidesmosome, the anchoring structures of the epithelia. This basal polarization is lost in migrating normal squamous cells and squamous carcinomas. Tyrosine phosphorylation of the Β4 subunit is absent or greatly reduced in malignant cells and this may be a critical signal for subcellular localization of Α6Β4 and cell anchoring. On the basis of our current experimental results, we postulate that tyrosine phosphorylation of the Β4 subunit is a reversible signal that regulates cell migration in normal and malignant cells, and may therefore be an important initial event in the metastatic cascade.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38454/1/240531033_ftp.pd

A COL17A1 Splice-Altering Mutation Is Prevalent in Inherited Recurrent Corneal Erosions

PurposeCorneal dystrophies are a genetically heterogeneous group of disorders. We previously described a family with an autosomal dominant epithelial recurrent erosion dystrophy (ERED). We aimed to identify the underlying genetic cause of ERED in this family and 3 additional ERED families. We sought to characterize the potential function of the candidate genes using the human and zebrafish cornea.DesignCase series study of 4 white families with a similar ERED. An experimental study was performed on human and zebrafish tissue to examine the putative biological function of candidate genes.ParticipantsFour ERED families, including 28 affected and 17 unaffected individuals.MethodsHumanLinkage-12 arrays (Illumina, San Diego, CA) were used to genotype 17 family members. Next-generation exome sequencing was performed on an uncle–niece pair. Segregation of potential causative mutations was confirmed using Sanger sequencing. Protein expression was determined using immunohistochemistry in human and zebrafish cornea. Gene expression in zebrafish was assessed using whole-mount in situ hybridization. Morpholino-induced transient gene knockdown was performed in zebrafish embryos.Main Outcome MeasuresLinkage microarray, exome analysis, DNA sequence analysis, immunohistochemistry, in situ hybridization, and morpholino-induced genetic knockdown results.ResultsLinkage microarray analysis identified a candidate region on chromosome chr10:12,576,562–112,763,135, and exploration of exome sequencing data identified 8 putative pathogenic variants in this linkage region. Two variants segregated in 06NZ–TRB1 with ERED: COL17A1 c.3156C→T and DNAJC9 c.334G→A. The COL17A1 c.3156C→T variant segregated in all 4 ERED families. We showed biologically relevant expression of these proteins in human cornea. Both proteins are expressed in the cornea of zebrafish embryos and adults. Zebrafish lacking Col17a1a and Dnajc9 during development show no gross corneal phenotype.ConclusionsThe COL17A1 c.3156C→T variant is the likely causative mutation in our recurrent corneal erosion families, and its presence in 4 independent families suggests that it is prevalent in ERED. This same COL17A1 c.3156C→T variant recently was identified in a separate pedigree with ERED. Our study expands the phenotypic spectrum of COL17A1 disease from autosomal recessive epidermolysis bullosa to autosomal dominant ERED and identifies COL17A1 as a key protein in maintaining integrity of the corneal epithelium

α6 Integrins Are Required for Langerhans Cell Migration from the Epidermis

Topical exposure of mice to chemical allergens results in the migration of epidermal Langerhans cells (LCs) from the skin and their accumulation as immunostimulatory dendritic cells (DCs) in draining lymph nodes. Epidermal cell–derived cytokines have been implicated in the maturation and migration of LCs, but the adhesion molecules that regulate LC migration have not been studied. We hypothesized that integrin-mediated interactions with extracellular matrix components of the skin and lymph node may regulate LC/DC migration. We found that α(6) integrins and α(4) integrins were differentially expressed by epidermal LCs and lymph node DCs. A majority of LCs (70%) expressed the α(6) integrin subunit, whereas DCs did not express α(6) integrins. In contrast, the α(4) integrin subunit was expressed at high levels on DCs but at much lower levels on LCs. The anti-α(6) integrin antibody, GoH3, which blocks binding to laminin, completely prevented the spontaneous migration of LCs from skin explants in vitro and the rapid migration of LCs from mouse ear skin induced after intradermal administration of TNF-α in vivo. GoH3 also reduced the accumulation of DCs in draining lymph nodes by a maximum of 70% after topical administration of the chemical allergen oxazolone. LCs remaining in the epidermis in the presence of GoH3 adopted a rounded morphology, rather than the interdigitating appearance typical of LCs in naive skin, suggesting that the cells had detached from neighboring keratinocytes and withdrawn cellular processes in preparation for migration, but were unable to leave the epidermis. The anti-α(4) integrin antibody PS/2, which blocks binding to fibronectin, had no effect on LC migration from the epidermis either in vitro or in vivo, or on the accumulation of DCs in draining lymph nodes after oxazolone application. RGD-containing peptides were also without effect on LC migration from skin explants. These results identify an important role for α(6) integrins in the migration of LC from the epidermis to the draining lymph node by regulating access across the epidermal basement membrane. In contrast, α(4) integrins, or other integrin-dependent interactions with fibronectin that are mediated by the RGD recognition sequence, did not influence LC migration from the epidermis. In addition, α(4) integrins did not affect the accumulation of LCs as DCs in draining lymph nodes

The role of titin and nebulin in myofibril assembly in cultured embryonic chick muscle cells

The purpose of this study was to examine the role of the two high molecular weight proteins, titin and nebulin, in skeletal muscle myofibrillogenesis. A monoclonal antibody against chicken breast titin was produced, and used in conjunction with polyclonal antibodies against chicken breast titin and nebulin, and monoclonal antibodies to actin and muscle-specific myosin in a series of double-label immunofluorescence studies to examine the organization of these proteins in cultured skeletal muscle cells derived from 12 day chick embryos. Postmitotic, mononucleated myoblasts synthesized titin, myosin, actin, and nebulin. Initial myofibril assembly events involved the coalescence of titin and myosin in a continuous pattern along actin containing structures morphologically similar to stress fibers. Titin and myosin organization into the skeletal muscle myofibril appeared to be coupled, as adult-like titin banding patterns were not observed in the absence of myosin organization into A bands. Titin and actin organization, in contrast, did not appear to be linked. Organization of titin into adult-like double bands along nascent myofibrils consistently preceded that of actin. Neither nebulin and myosin nor nebulin and titin assembly appeared to be linked, since the appearance of nebulin banding was seen after the formation of titin and myosin bands along nascent myofibrils. Nebulin organization occurred either at the same time or after the assembly of actin into I bands. A possible correlation between the formation of adult-like nebulin double bands and the appearance of phase-dense Z lines was noted, however. Labeling experiments were repeated with cultures exposed to the mutagenic alkylating agent ethyl methanesulfonate (EMS). The results of labeling experiments of EMS cells confirmed those found in the normal culture system. In conclusion, it appears that titin does not play a scaffolding or template role for subsequent thick filament alignment into A bands. The possibility of a template role for thin filament alignment into I bands can not be excluded, however, because titin organization precedes actin. The relationship between nebulin organization and the appearance of Z lines suggests that nebulin may be involved in Z line assembly or may regulate the insertion of thin filaments into Z lines.</p