Involvement of NADPH oxidases in alkali burn-induced corneal injury.

PubMed

Gu, Xue-Jun; Liu, Xian; Chen, Ying-Ying; Zhao, Yao; Xu, Man; Han, Xiao-Jian; Liu, Qiu-Ping; Yi, Jing-Lin; Li, Jing-Ming

2016-07-01

Chemical burns are a major cause of corneal injury. Oxidative stress, inflammatory responses and neovascularization after the chemical burn aggravate corneal damage, and lead to loss of vision. Although NADPH oxidases (Noxs) play a crucial role in the production of reactive oxygen species (ROS), the role of Noxs in chemical burn-induced corneal injury remains to be elucidated. In the present study, the transcription and expression of Noxs in corneas were examined by RT-qPCR, western blot analysis and immunofluorescence staining. It was found that alkali burns markedly upregulated the transcription and expression of Nox2 and Nox4 in human or mouse corneas. The inhibition of Noxs by diphenyleneiodonium (DPI) or apocynin (Apo) effectively attenuated alkali burn-induced ROS production and decreased 3-nitrotyrosine (3-NT) protein levels in the corneas. In addition, Noxs/CD11b double‑immunofluorescence staining indicated that Nox2 and Nox4 were partially co-localized with CD11b. DPI or Apo prevented the infiltration of CD11b-positive inflammatory cells, and inhibited the transcription of inflammatory cytokines following alkali burn-induced corneal injury. In our mouse model of alkali burn-induced corneal injury, corneal neovascularization (CNV) occurred on day 3, and it affected 50% of the whole area of the cornea on day 7, and on day 14, CNV coverage of the cornea reached maximum levels. DPI or Apo effectively attenuated alkali burn‑induced CNV and decreased the mRNA levels of angiogenic factors, including vascular endothelial growth factor (VEGF), VEGF receptors and matrix metalloproteinases (MMPs). Taken together, our data indicate that Noxs play a role in alkali burn-induced corneal injury by regulating oxidative stress, inflammatory responses and CNV, and we thus suggest that Noxs are a potential therapeutic target in the future treatment of chemical-induced corneal injury.

Therapeutic potential of trichostatin A to control inflammatory and fibrogenic disorders of the ocular surface.

PubMed

Kitano, Ai; Okada, Yuka; Yamanka, Osamu; Shirai, Kumi; Mohan, Rajiv R; Saika, Shizuya

2010-12-31

To examine the effects of a histone deacetylase inhibitor, Trichostatin A (TSA), on the behavior of macrophages and subconjunctival fibroblasts in vitro and on ocular surface inflammation and scarring in vivo using an alkali burn wound healing model. Effects of TSA on expression of inflammation-related growth factors or collagen I were examined by real-time RT-PCR or immunoassay in mouse macrophages or human subconjunctival fibroblasts. Effects of TSA on trans forming growth factor β (TGFβ)/Smad signaling were evaluated with western blotting and/or immunocytochemistry. Alkali-burn injuries on the eyes of mice were performed with three µl of 0.5 N NaOH under general and topical anesthesia. TSA (600 µg/Kg daily) or vehicle was administered to animals via intraperitoneal (i.p.) injection. Histology and real-time RT-PCR investigations evaluated the effects of TSA on the healing process of the cornea. TSA inhibited TGFβ 1 and vascular endothelial growth factor (VEGF) expression in macrophages, and TGFβ1 and collagen I in ocular fibroblasts. It elevated the expression of 5'-TG-3'-interacting factor (TGIF) and Smad7 in fibroblasts and blocked nuclear translocation of phospho-Smad2. Real-time PCR and immunocytochemistry studies showed that systemic administration of TSA suppressed the inflammation and fibrotic response in the stroma and accelerated epithelial healing in the alkali-burned mouse cornea. Systemic administration of TSA reduces inflammatory and fibrotic responses in the alkali-burned mouse ocular surface in vivo. The mechanisms of action involve attenuation of Smad signal in mesenchymal cells and reduction in the activation and recruitment of macrophages. TSA has the potential to treat corneal scarring in vivo.

Inflammatory response in multiple organs in a mouse model of acute alcohol intoxication and burn injury*

PubMed Central

Li, Xiaoling; Akhtar, Suhail; Kovacs, Elizabeth J.; Gamelli, Richard L.; Choudhry, Mashkoor A.

2011-01-01

The present study characterized the inflammatory response following burn injury and determined whether ethanol (EtOH) intoxication at the time of burn injury influences this response. To accomplish this, male mice were gavaged with EtOH (2.9 g/Kg) 4 hours prior to 12–15% total body surface area sham or burn injury. Mice were sacrificed on day one after injury; blood, small intestine, lung and liver were collected to measure IL-6, IL-10, IL-18 and MCP-1 levels. In addition, neutrophil infiltration, MPO activity and edema formation were also measured in the small intestine, lung and liver. There was no difference in the inflammatory markers in the small intestine, lung and liver in mice receiving either sham or burn injury alone except IL-6 which was increased in all 4 tissue compartments following burn injury alone. However, as compared to EtOH or burn injury alone, EtOH combined with burn injury resulted in a significant increase in cytokines, neutrophil infiltration, MPO activity and edema in the small intestine, liver and lung tissue. Furthermore, a significant increase in IL-6 and MCP-1 was observed in circulation following EtOH and burn injury compared to either EtOH intoxication or burn injury alone, no other cytokines were detected in circulation. These findings suggest that acute EtOH intoxication exacerbates the inflammatory response following burn injury. PMID:21593683

Chemopreventive activity of compounds extracted from Casearia sylvestris (Salicaceae) Sw against DNA damage induced by particulate matter emitted by sugarcane burning near Araraquara, Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prieto, A.M.; Santos, A.G.; Csipak, A.R.

Ethanolic extract of Casearia sylvestris is thought to be antimutagenic. In this study, we attempted to determine whether this extract and casearin X (a clerodane diterpene from C. sylvestris) are protective against the harmful effects of airborne pollutants from sugarcane burning. To that end, we used the Tradescantia micronucleus test in meiotic pollen cells of Tradescantia pallida, the micronucleus test in mouse bone marrow cells, and the comet assay in mouse blood cells. The mutagenic compound was total suspended particulate (TSP) from air. For the Tradescantia micronucleus test, T. pallida cuttings were treated with the extract at 0.13, 0.25, ormore » 0.50 mg/ml. Subsequently, TSP was added at 0.3 mg/ml, and tetrads from the inflorescences were examined for micronuclei. For the micronucleus test in mouse bone marrow cells and the comet assay in mouse blood cells, Balb/c mice were treated for 15 days with the extract—3.9, 7.5, or 15.0 mg/kg body weight (BW)—or with casearin X—0.3, 0.25, or 1.2 mg/kg BW—after which they received TSP (3.75 mg/kg BW). In T. pallida and mouse bone marrow cells, the extract was antimutagenic at all concentrations tested. In mouse blood cells, the extract was antigenotoxic at all concentrations, whereas casearin X was not antimutagenic but was antigenotoxic at all concentrations. We conclude that C. sylvestris ethanolic extract and casearin X protect DNA from damage induced by airborne pollutants from sugarcane burning. -- Highlights: ► We assessed DNA protection of C. sylvestris ethanolic extract. ► We assessed DNA protection of casearin X. ► We used Tradescantia pallida micronucleus test as screening. ► We used comet assay and micronucleus test in mice. ► The compounds protected DNA against sugar cane burning pollutants.« less

Aging impairs the mobilization and homing of bone marrow-derived angiogenic cells to burn wounds

PubMed Central

Zhang, Xianjie; Sarkar, Kakali; Rey, Sergio; Sebastian, Raul; Andrikopoulou, Efstathia; Marti, Guy P.; Fox-Talbot, Karen

2013-01-01

Impaired wound healing in the elderly represents a major clinical problem. Delineating the cellular and molecular mechanisms by which aging impairs wound healing may lead to the development of improved treatment strategies for elderly patients with non-healing wounds. Neovascularization is an essential step in wound healing, and bone marrow-derived angiogenic cells (BMDACs) play an important role in vascularization. Using a mouse full-thickness burn wound model, we demonstrate that perfusion and vascularization of burn wounds were impaired by aging and were associated with dramatically reduced mobilization of BMDACs bearing the cell surface molecules CXCR4 and Sca1. Expression of stromal-derived factor 1 (SDF-1), the cytokine ligand for CXCR4, was significantly decreased in peripheral blood and burn wounds of old mice. Expression of hypoxia-inducible factor (HIF)-1α was detected in burn wounds from young (2-month-old), but not old (2-year-old), mice. When BMDACs from young donor mice were injected intravenously, homing to burn wound tissue was impaired in old recipient mice, whereas the age of the BMDAC donor mice had no effect on homing. Our results indicate that aging impairs burn wound vascularization by impairing the mobilization of BMDACs and their homing to burn wound tissue as a result of impaired HIF-1 induction and SDF-1 signaling. PMID:21499736

Ethanol exacerbates T cell dysfunction after thermal injury.

PubMed

Choudhry, M A; Messingham, K A; Namak, S; Colantoni, A; Fontanilla, C V; Duffner, L A; Sayeed, M M; Kovacs, E J

2000-07-01

To understand the mechanism of suppressed immunity following alcohol consumption and thermal injury, we analyzed T cell functions in a mouse model of acute alcohol exposure and burn injury. Mice with blood alcohol levels at approximately 100 mg/dl were given a 15% scald or sham injury. Mice were sacrificed 48 h after injury. Our data demonstrated a 20-25% decrease in Con A-mediated splenic T cell proliferation (p<0.01) and 45-50% decrease in interleukin-2 (IL-2) production (p<0.01) following burn injury compared to the T cells from sham animals. A further decrease in the proliferation (25-30%) and IL-2 production (40-45%) was detected in T cells derived from burned animals receiving alcohol as compared to burn alone. No significant change in the proliferation and IL-2 production was observed in splenic T cells derived from sham-injured mice regardless of alcohol exposure. Additionally, there was no demonstrable difference in splenocyte apoptosis in any treatment group. These results suggest that alcohol consumption prior to burn injury causes a greater decrease in T cell proliferation and IL-2 production compared to either burn or alcohol injury alone that may further attenuate the cell-mediated immunity and thus enhance susceptibility to infection.

Myelo-erythroid commitment after burn injury is under β-adrenergic control via MafB regulation.

PubMed

Hasan, Shirin; Johnson, Nicholas B; Mosier, Michael J; Shankar, Ravi; Conrad, Peggie; Szilagyi, Andrea; Gamelli, Richard L; Muthumalaiappan, Kuzhali

2017-03-01

Severely injured burn patients receive multiple blood transfusions for anemia of critical illness despite the adverse consequences. One limiting factor to consider alternate treatment strategies is the lack of a reliable test platform to study molecular mechanisms of impaired erythropoiesis. This study illustrates how conditions resulting in a high catecholamine microenvironment such as burns can instigate myelo-erythroid reprioritization influenced by β-adrenergic stimulation leading to anemia. In a mouse model of scald burn injury, we observed, along with a threefold increase in bone marrow LSK cells (lin neg Sca1 + cKit + ), that the myeloid shift is accompanied with a significant reduction in megakaryocyte erythrocyte progenitors (MEPs). β-Blocker administration (propranolol) for 6 days after burn, not only reduced the number of LSKs and MafB + cells in multipotent progenitors, but also influenced myelo-erythroid bifurcation by increasing the MEPs and reducing the granulocyte monocyte progenitors in the bone marrow of burn mice. Furthermore, similar results were observed in burn patients' peripheral blood mononuclear cell-derived ex vivo culture system, demonstrating that commitment stage of erythropoiesis is impaired in burn patients and intervention with propranolol (nonselective β1,2-adrenergic blocker) increases MEPs. Also, MafB + cells that were significantly increased following standard burn care could be mitigated when propranolol was administered to burn patients, establishing the mechanistic regulation of erythroid commitment by myeloid regulatory transcription factor MafB. Overall, results demonstrate that β-adrenergic blockers following burn injury can redirect the hematopoietic commitment toward erythroid lineage by lowering MafB expression in multipotent progenitors and be of potential therapeutic value to increase erythropoietin responsiveness in burn patients. Copyright © 2017 the American Physiological Society.

Myelo-erythroid commitment after burn injury is under β-adrenergic control via MafB regulation

PubMed Central

Hasan, Shirin; Johnson, Nicholas B.; Mosier, Michael J.; Shankar, Ravi; Conrad, Peggie; Szilagyi, Andrea; Gamelli, Richard L.

2017-01-01

Severely injured burn patients receive multiple blood transfusions for anemia of critical illness despite the adverse consequences. One limiting factor to consider alternate treatment strategies is the lack of a reliable test platform to study molecular mechanisms of impaired erythropoiesis. This study illustrates how conditions resulting in a high catecholamine microenvironment such as burns can instigate myelo-erythroid reprioritization influenced by β-adrenergic stimulation leading to anemia. In a mouse model of scald burn injury, we observed, along with a threefold increase in bone marrow LSK cells (linneg Sca1+cKit+), that the myeloid shift is accompanied with a significant reduction in megakaryocyte erythrocyte progenitors (MEPs). β-Blocker administration (propranolol) for 6 days after burn, not only reduced the number of LSKs and MafB+ cells in multipotent progenitors, but also influenced myelo-erythroid bifurcation by increasing the MEPs and reducing the granulocyte monocyte progenitors in the bone marrow of burn mice. Furthermore, similar results were observed in burn patients’ peripheral blood mononuclear cell-derived ex vivo culture system, demonstrating that commitment stage of erythropoiesis is impaired in burn patients and intervention with propranolol (nonselective β1,2-adrenergic blocker) increases MEPs. Also, MafB+ cells that were significantly increased following standard burn care could be mitigated when propranolol was administered to burn patients, establishing the mechanistic regulation of erythroid commitment by myeloid regulatory transcription factor MafB. Overall, results demonstrate that β-adrenergic blockers following burn injury can redirect the hematopoietic commitment toward erythroid lineage by lowering MafB expression in multipotent progenitors and be of potential therapeutic value to increase erythropoietin responsiveness in burn patients. PMID:28031160

Wildfires alter rodent community structure across four vegetation types in southern California, USA

USGS Publications Warehouse

Brehme, Cheryl S.; Clark, Denise R.; Rochester, Carlton J.; Fisher, Robert N.

2011-01-01

We surveyed burned and unburned plots across four habitat reserves in San Diego County, California, USA, in 2005 and 2006, to assess the effects of the 2003 wildfires on the community structure and relative abundance of rodent species. The reserves each contained multiple vegetation types (coastal sage scrub, chaparral, woodland, and grassland) and spanned from 250 m to 1078 m in elevation. Multivariate analyses revealed a more simplified rodent community structure in all burned habitats in comparison to unburned habitats. Reduction in shrub and tree cover was highly predictive of changes in post-fire rodent community structure in the burned coastal sage scrub and chaparral habitats. Reduction in cover was not predictive for the less substantially burned woodlands and grasslands, for which we hypothesized that interspecific competition played a greater role in post-fire community structure. Across vegetation types, generalists and open habitat specialists typically increased in relative abundance, whereas closed habitat specialists decreased. We documented significant increases in relative abundance of the deer mouse (Peromyscus maniculatus Wagner) and Dulzura kangaroo rat (Dipodomys simulans Merriam). In contrast, we found significant decreases in relative abundance for the California mouse (Peromyscus californicus Gambel), San Diego pocket mouse (Chaetodipus fallax Merriam), desert woodrat (Neotoma lepida Thomas), and brush mouse (Peromyscus boylii Baird). Currently, our research program involves assessment of whether habitat conservation plans (HCPs) in southern California provide long-term protection to HCP covered species, as well as preserve ecosystem function. The scenario of increased wildfires needs to be incorporated into this assessment. We discuss our results in relation to management and conservation planning under a future scenario of larger and more frequent wildfires in southern California.

Down-regulation of glutatione S-transferase α 4 (hGSTA4) in the muscle of thermally injured patients is indicative of susceptibility to bacterial infection

PubMed Central

Apidianakis, Yiorgos; Que, Yok-Ai; Xu, Weihong; Tegos, George P.; Zimniak, Piotr; Hamblin, Michael R.; Tompkins, Ronald G.; Xiao, Wenzhong; Rahme, Laurence G.

2012-01-01

Patients with severe burns are highly susceptible to bacterial infection. While immunosuppression facilitates infection, the contribution of soft tissues to infection beyond providing a portal for bacterial entry remains unclear. We showed previously that glutathione S-transferase S1 (gstS1), an enzyme with conjugating activity against the lipid peroxidation byproduct 4-hydroxynonenal (4HNE), is important for resistance against wound infection in Drosophila muscle. The importance of the mammalian functional counterpart of GstS1 in the context of wounds and infection has not been investigated. Here we demonstrate that the presence of a burn wound dramatically affects expression of both human (hGSTA4) and mouse (mGsta4) 4HNE scavengers. hGSTA4 is down-regulated significantly within 1 wk of thermal burn injury in the muscle and fat tissues of patients from the large-scale collaborative Inflammation and the Host Response to Injury multicentered study. Similarly, mGsta4, the murine GST with the highest catalytic efficiency for 4HNE, is down-regulated to approximately half of normal levels in mouse muscle immediately postburn. Consequently, 4HNE protein adducts are increased 4- to 5-fold in mouse muscle postburn. Using an open wound infection model, we show that deletion of mGsta4 renders mice more susceptible to infection with the prevalent wound pathogen Pseudomonas aeruginosa, while muscle hGSTA4 expression negatively correlates with burn wound infection episodes per patient. Our data suggest that hGSTA4 down-regulation and the concomitant increase in 4HNE adducts in human muscle are indicative of susceptibility to infection in individuals with severely thermal injuries.—Apidianakis, Y., Que, Y.-A., Xu, W., Tegos, G. P., Zimniak, P., Hamblin, M. R., Tompkins, R. G., Xiao, W., Rahme, L. G. Down-regulation of glutatione S-transferase α 4 (hGSTA4) in the muscle of thermally injured patients is indicative of susceptibility to bacterial infection. PMID:22038048

Blue Light Rescues Mice from Potentially Fatal Pseudomonas aeruginosa Burn Infection: Efficacy, Safety, and Mechanism of Action

PubMed Central

Dai, Tianhong; Gupta, Asheesh; Huang, Ying-Ying; Yin, Rui; Murray, Clinton K.; Vrahas, Mark S.; Sherwood, Margaret E.; Tegos, George P.

2013-01-01

Blue light has attracted increasing attention due to its intrinsic antimicrobial effect without the addition of exogenous photosensitizers. However, the use of blue light for wound infections has not been established yet. In this study, we demonstrated the efficacy of blue light at 415 nm for the treatment of acute, potentially lethal Pseudomonas aeruginosa burn infections in mice. Our in vitro studies demonstrated that the inactivation rate of P. aeruginosa cells by blue light was approximately 35-fold higher than that of keratinocytes (P = 0.0014). Transmission electron microscopy revealed blue light-mediated intracellular damage to P. aeruginosa cells. Fluorescence spectroscopy suggested that coproporphyrin III and/or uroporphyrin III are possibly the intracellular photosensitive chromophores associated with the blue light inactivation of P. aeruginosa. In vivo studies using an in vivo bioluminescence imaging technique and an area-under-the-bioluminescence-time-curve (AUBC) analysis showed that a single exposure of blue light at 55.8 J/cm2, applied 30 min after bacterial inoculation to the infected mouse burns, reduced the AUBC by approximately 100-fold in comparison with untreated and infected mouse burns (P < 0.0001). Histological analyses and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays indicated no significant damage in the mouse skin exposed to blue light at the effective antimicrobial dose. Survival analyses revealed that blue light increased the survival rate of the infected mice from 18.2% to 100% (P < 0.0001). In conclusion, blue light therapy might offer an effective and safe alternative to conventional antimicrobial therapy for P. aeruginosa burn infections. PMID:23262998

Involvement of peripheral artemin signaling in tongue pain: possible mechanism in burning mouth syndrome.

PubMed

Shinoda, Masamichi; Takeda, Mamoru; Honda, Kuniya; Maruno, Mitsuru; Katagiri, Ayano; Satoh-Kuriwada, Shizuko; Shoji, Noriaki; Tsuchiya, Masahiro; Iwata, Koichi

2015-12-01

Burning mouth syndrome is characterized by altered sensory qualities, namely tongue pain hypersensitivity. We found that the mRNA expression of Artemin (Artn) in the tongue mucosa of patients with burning mouth syndrome was significantly higher than that of control subjects, and we developed a mouse model of burning mouth syndrome by application of 2,4,6-trinitrobenzene sulfonic acid (TNBS) diluted with 50% ethanol to the dorsum of the tongue. TNBS treatment to the tongue induced persistent, week-long, noninflammatory tongue pain and a significant increase in Artn expression in the tongue mucosa and marked tongue heat hyperalgesia. Following TNBS treatment, the successive administration of the transient receptor potential vanilloid 1 (TRPV1) antagonist SB366791 or neutralizing anti-Artn antibody completely inhibited the heat hyperalgesia. The number of glial cell line-derived neurotrophic factor family receptor α3 (GFRα3)-positive and TRPV1-positive trigeminal ganglion (TG) neurons innervating the tongue significantly increased following TNBS treatment and was significantly reduced by successive administration of neutralizing anti-Artn antibody. The capsaicin-induced current in TG neurons innervating the tongue was enhanced following TNBS treatment and was inhibited by local administration of neutralizing anti-Artn antibody to the tongue. These results suggest that the overexpression of Artn in the TNBS-treated tongue increases the membrane excitability of TG neurons innervating the tongue by increasing TRPV1 sensitivity, which causes heat hyperalgesia. This model may be useful for the study of tongue pain hypersensitivity associated with burning mouth syndrome.

The healing effect of electrolytic-reduction ion water on burn wounds.

PubMed

Okajima, Masahiro; Shimokawa, Ken-ichi; Ishii, Fumiyoshi

2010-02-01

We prepared a lotion using electrolytic-reduction ion water (ERI), and evaluated the healing effects of this lotion (ERI lotion) on burn wounds. Third degree burn wounds were induced in the mouse dorsal skin, and ERI lotion or physiological salt (PS) lotion was applied to the wounds from immediately after injury [ERI (+) group and ERI (-) group as a control group, respectively]. The burn wound area was measured, and its serial changes were evaluated. In addition, histological examination of the burn wound site (on day 3) was performed. Comparison of the ERI (+) and (-) groups showed a significant reduction in the burn wound area in the former. Histological examination confirmed many interstitial spaces, blood vessels, and lymphatic vessels in the subcutaneous tissue in the ERI (-) compared with the ERI (+) group. These results suggest the promotion of burn wound healing by ERI lotion.

miR-27b Represses Migration of Mouse MSCs to Burned Margins and Prolongs Wound Repair through Silencing SDF-1a

PubMed Central

Chen, Ling; Peng, Xi; Chen, Jian; Hu, Jiong-Yu; Teng, Miao; Liang, Guang-Ping

2013-01-01

Background Interactions between stromal cell-derived factor-1α (SDF-1α) and its cognate receptor CXCR4 are crucial for the recruitment of mesenchymal stem cells (MSCs) from bone marrow (BM) reservoirs to damaged tissues for repair during alarm situations. MicroRNAs are differentially expressed in stem cell niches, suggesting a specialized role in stem cell regulation. Here, we gain insight into the molecular mechanisms involved in regulating SDF-1α. Methods MSCs from green fluorescent protein transgenic male mice were transfused to irradiated recipient female C57BL/6 mice, and skin burn model of bone marrow-chimeric mice were constructed. Six miRNAs with differential expression in burned murine skin tissue compared to normal skin tissue were identified using microarrays and bioinformatics. The expression of miR-27b and SDF-1α was examined in burned murine skin tissue using quantitative real-time PCR (qPCR) and immunohistochemistry (IHC), enzyme-linked immunosorbent assay (ELISA). The Correlation of miR-27b and SDF-1α expression was analyzed by Pearson analysis Correlation. miRNAs suppressed SDF-1α protein expression by binding directly to its 3′UTR using western blot and luciferase reporter assay. The importance of miRNAs in MSCs chemotaxis was further estimated by decreasing SDF-1α in vivo and in vitro. Results miR-23a, miR-27a and miR-27b expression was significantly lower in the burned skin than in the normal skin (p<0.05). We also found that several miRNAs suppressed SDF-1α protein expression, while just miR-27a and miR-27b directly bound to the SDF-1α 3′UTR. Moreover, the forced over-expression of miR-27a and miR-27b significantly reduced the directional migration of mMSCs in vitro. However, only miR-27b in burn wound margins significantly inhibited the mobilization of MSCs to the epidermis. Conclusion miR-27b may be a unique signature of the stem cell niche in burned mouse skin and can suppress the directional migration of mMSCs by targeting SDF-1α by binding directly to its 3′UTR. PMID:23894385

Thermal Stimulation of the Retina Reduces Bruch's Membrane Thickness in Age Related Macular Degeneration Mouse Models.

PubMed

Tode, Jan; Richert, Elisabeth; Koinzer, Stefan; Klettner, Alexa; von der Burchard, Claus; Brinkmann, Ralf; Lucius, Ralph; Roider, Johann

2018-05-01

To investigate the effect of thermal stimulation of the retina (TS-R) on Bruch's membrane (BrM) thickness in age-related macular degeneration (AMD) mouse models as a novel concept for the prophylaxis and treatment of dry AMD. Two knockout AMD mouse models, B6.129P2-Apoe tm1Unc /J (ApoE-/-) and B6.129X1-Nfe2I2 tm1Ywk /J (NRF2-/-), were chosen. One randomized eye of each mouse in four different groups (two of different age, two of different genotype) of five mice was treated by TS-R (532 nm, 10-ms duration, 50-μm spot size), the fellow eye served as control. Laser power was titrated to barely visible laser burns, then reduced by 70% to guarantee for thermal elevation without damage to the neuroretina, then applied uniformly to the murine retina. Fundus, optical coherence tomography (OCT), and fluorescein angiography (FLA) images were obtained at the day of treatment and 1 month after treatment. Eyes were enucleated thereafter to analyze BrM thickness by transmission electron microscopy (TEM) in a standardized blinded manner. Fundus images revealed that all ApoE-/- and NRF2-/- mice had AMD associated retinal alterations. BrM thickness was increased in untreated controls of both mouse models. Subvisible TS-R laser spots were not detectable by fundus imaging, OCT, or FLA 2 hours or 1 month after laser treatment. TEM revealed a significant reduction of BrM thickness in laser-treated eyes of all four groups compared to their fellow control eyes. TS-R reduces BrM thickness in AMD mouse models ApoE-/- and NRF2-/- without damage to the neuroretina. It may become a prophylactic or even therapeutic treatment option for dry AMD. TS-R may become a prophylactic or even therapeutic treatment option for dry AMD.

Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Wang, Yucheng; Dai, Tianhong; Gu, Ying

2016-10-01

Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

In vitro and in vivo assessment of lactic acid-modified chitosan scaffolds for potential treatment of full-thickness burns.

PubMed

Velasquillo, Cristina; Silva-Bermudez, Phaedra; Vázquez, Nadia; Martínez, Alan; Espadín, Andres; García-López, Julieta; Medina-Vega, Antonio; Lecona, Hugo; Pichardo-Baena, Raúl; Ibarra, Clemente; Shirai, Keiko

2017-10-01

Autologous skin transplantation is today's "gold standard" treatment for full-thickness burns. However, when > 30% of total body surface area is damaged, there is an important shortage of autologous donor sites for skin grafting; then, treatment alternatives become crucial. Such alternatives can be based on polymeric scaffolds capable of functioning as protective covers and cells/factors carriers. Chitosan (CTS) is a natural-derived polymer with relevant biological-related properties but poor mechanical performance. Improved mechanical properties can be achieved through lactic acid grafting (LA-g); nevertheless, LA-g affects the biological response towards the CTS-based materials. In this work, CTS-LA scaffolds with different LA-g percentages were synthesized and evaluated to determine appropriate LA-g degrees for full-thickness burns treatment. In vitro results indicated that the higher the LA-g percentage, the lower the capability of the scaffolds to sustain fibroblasts culture. Scaffolds with LA-g around 28% (CTS-LA28) sustained cell culture and allowed normal cell functionality. Further evaluation of CTS-LA28 as acellular and cellular grafts in a full-thickness burn mouse model showed that at 28 days post-burn, macroscopic characteristic of the reparation tissue were closer to healthy skin when cellular grafts were used for treatment; histological evaluation also showed that dermis cellularity and collagenous fibers structure were similar to those in healthy skin when cellular grafts were used for burns treatment. © 2017 Wiley Periodicals Inc. J Biomed Mater Res Part A: 105A: 2875-2891, 2017. © 2017 Wiley Periodicals, Inc.

Assessment of edema volume in skin upon injury in a mouse ear model with optical coherence tomography

PubMed Central

Qin, Wan

2017-01-01

Accurate measurement of edema volume is essential for the investigation of tissue response and recovery following a traumatic injury. The measurements must be noninvasive and repetitive over time so as to monitor tissue response throughout the healing process. Such techniques are particularly necessary for the evaluation of therapeutics that are currently in development to suppress or prevent edema formation. In this study, we propose to use optical coherence tomography (OCT) technique to image and quantify edema in a mouse ear model where the injury is induced by a superficial-thickness burn. Extraction of edema volume is achieved by an attenuation compensation algorithm performed on the three-dimensional OCT images, followed by two segmentation procedures. In addition to edema volume, the segmentation method also enables accurate thickness mapping of edematous tissue, which is an important characteristic of the external symptoms of edema. To the best of our knowledge, this is the first method for noninvasively measuring absolute edema volume. PMID:27282161

Modeling the effects of fire severity and spatial complexity on Small Mammals in Yosemite National Park, California

USGS Publications Warehouse

Roberts, Susan L.; Van Wagtendonk, Jan W.; Miles, A. Keith; Kelt, Douglas A.; Lutz, James A.

2008-01-01

We evaluated the impact of fire severity and related spatial and vegetative parameters on small mammal populations in 2 yr- to 15 yr-old burns in Yosemite National Park, California, USA. We also developed habitat models that would predict small mammal responses to fires of differing severity. We hypothesized that fire severity would influence the abundances of small mammals through changes in vegetation composition, structure, and spatial habitat complexity. Deer mouse (Peromyscus maniculatus) abundance responded negatively to fire severity, and brush mouse (P. boylii) abundance increased with increasing oak tree (Quercus spp.) cover. Chipmunk (Neotamias spp.) abundance was best predicted through a combination of a negative response to oak tree cover and a positive response to spatial habitat complexity. California ground squirrel (Spermophilus beecheyi) abundance increased with increasing spatial habitat complexity. Our results suggest that fire severity, with subsequent changes in vegetation structure and habitat spatial complexity, can influence small mammal abundance patterns.

Susceptibility of thermally injured mice to cytomegalovirus infection.

PubMed

Kobayashi, H; Kobayashi, M; Herndon, D N; Pollard, R B; Suzuki, F

2001-11-01

Thermally injured patients are very susceptible to infection with cytomegaloviruses. In this study a role of burn-associated type 2 T cell responses on the cytomegalovirus infection was examined in a mouse model of thermal injury. A predominance of type 2 T cell responses in splenic lymphocytes of thermally injured mice has been previously demonstrated. SCID mice inoculated with splenic T cells from thermally injured mice were susceptible to infection with a small amount (5 PFU/mouse) of murine cytomegalovirus (MCMV). Conversely, SCID mice inoculated with splenic T cells from normal mice were resistant to the same infection. High levels of IL-4 and IL-10, but not IFN-gamma and IL-2, were detected in sera of thermally injured mice (TI-mice) infected with MCMV when those were compared with sera of normal mice infected with MCMV. IL-4 and IL-10 (type 2 cytokines) were produced by splenic T cells from MCMV-infected TI-mice, when they were stimulated in vitro with anti-CD3 mAb. Type 1 cytokines (IFN-gamma and IL-2), however, were not produced by these T cells after the same stimulation. In contrast, splenic T cells from MCMV-infected normal mice produced type 1 cytokines by the stimulation with anti-CD3 mAb. These results suggest that the susceptibility of mice to MCMV infection is markedly influenced by burn-associated type 2 T cell responses.

Preclinical advantages of intramuscularly administered peptide A3-APO over existing therapies in Acinetobacter baumannii wound infections.

PubMed

Ostorhazi, Eszter; Rozgonyi, Ferenc; Sztodola, Andras; Harmos, Ferenc; Kovalszky, Ilona; Szabo, Dora; Knappe, Daniel; Hoffmann, Ralf; Cassone, Marco; Wade, John D; Bonomo, Robert A; Otvos, Laszlo

2010-11-01

The designer antibacterial peptide A3-APO is efficacious in mouse models of Escherichia coli and Acinetobacter baumannii systemic infections. Here we compare the efficacy of the peptide with that of imipenem and colistin in A. baumannii wound infections after burn injury. CD-1 mice were inflicted with burn wounds and different inocula of A. baumannii, isolated from an injured soldier, were placed into the wound sites. The antibiotics were given intramuscularly (im) one to five times. Available free peptide in the blood and the systemic toxicity of colistin and A3-APO were studied in healthy mice. While toxicity of colistin was observed at 25 mg/kg bolus drug administration, the lowest toxic dose of A3-APO was 75 mg/kg. In the A. baumannii blast injury models, 5 mg/kg A3-APO improved survival and reduced bacterial counts in the blood as well as in the wounds and improved wound appearance significantly better than any other antibiotic treatment. The free peptide concentration in the blood did not reach 1 µg/mL. Peptide A3-APO, with an intramuscular therapeutic index of 15, is more efficacious and less toxic than any existing burn injury infection therapy modality against multidrug-resistant Gram-negative pathogens. A3-APO administered by the im route probably binds to a biopolymer that promotes the peptide's biodistribution.

Therapeutic Effect of Topical Administration of SN50, an Inhibitor of Nuclear Factor-κB, in Treatment of Corneal Alkali Burns in Mice

PubMed Central

Saika, Shizuya; Miyamoto, Takeshi; Yamanaka, Osamu; Kato, Tadashi; Ohnishi, Yoshitaka; Flanders, Kathleen C.; Ikeda, Kazuo; Nakajima, Yuji; Kao, Winston W.-Y.; Sato, Misako; Muragaki, Yasuteru; Ooshima, Akira

2005-01-01

We evaluated the therapeutic efficacy of topical administration of SN50, an inhibitor of nuclear factor-κB, in a corneal alkali burn model in mice. An alkali burn was produced with 1 N NaOH in the cornea of C57BL/6 mice under general anesthesia. SN50 (10 μg/μl) or vehicle was topically administered daily for up to 12 days. The eyes were processed for histological or immunohistochemical examination after bromodeoxyuridine labeling or for semiquantification of cytokine mRNA. Topical SN50 suppressed nuclear factor-κB activation in local cells and reduced the incidence of epithelial defects/ulceration in healing corneas. Myofibroblast generation, macrophage invasion, activity of matrix metalloproteinases, basement membrane destruction, and expression of cytokines were all decreased in treated corneas compared with controls. To elucidate the role of tumor necrosis factor (TNF)-α in epithelial cell proliferation, we performed organ culture of mouse eyes with TNF-α, SN50, or an inhibitor of c-Jun N-terminal kinase (JNK) and examined cell proliferation in healing corneal epithelium in TNF-α−/− mice treated with SN50. An acceleration of epithelial cell proliferation by SN50 treatment was found to depend on TNF-α/JNK signaling. In conclusion, topical application of SN50 is effective in treating corneal alkali burns in mice. PMID:15855640

Evaluation of Permacol as a cultured skin equivalent.

PubMed

MacLeod, T M; Cambrey, A; Williams, G; Sanders, R; Green, C J

2008-12-01

Skin loss following severe burn requires prompt wound closure to avoid such complications as fluid and electrolyte imbalance, infection, immune suppression, and pain. In clinical situations in which insufficient donor skin is available, the development of cultured skin equivalents (dermal matrices seeded with keratinocytes and fibroblasts) may provide a useful alternative. The aim of this study was to assess the suitability of a porcine-derived dermal collagen matrix (Permacol) to function as a cultured skin equivalent in supporting the growth of keratinocytes in vitro and providing cover to full thickness wounds in the BALB C/nude mouse model. A histological comparison was against Glycerol treated-Ethylene Oxide Sterilised Porcine Dermis (Gly-EO Dermis) which has successfully been used as a cultured skin equivalent in previous studies. Both Gly-EO Dermis and to a lesser extent Permacol were able to support the growth of cultured keratinocytes following a 16-day period of cell culture, however, this study was only able to demonstrate the presence of an epidermal layer on Gly-EO dermis 2 weeks after grafting onto full-thickness wounds in the BALB C/nude mouse model.

In vivo high-resolution 3D photoacoustic imaging of superficial vascular anatomy

NASA Astrophysics Data System (ADS)

Zhang, E. Z.; Laufer, J. G.; Pedley, R. B.; Beard, P. C.

2009-02-01

The application of a photoacoustic imaging instrument based upon a Fabry-Perot polymer film ultrasound sensor to imaging the superficial vasculature is described. This approach provides a backward mode-sensing configuration that has the potential to overcome the limitations of current piezoelectric based detection systems used in superficial photoacoustic imaging. The system has been evaluated by obtaining non-invasive images of the vasculature in human and mouse skin as well as mouse models of human colorectal tumours. These studies showed that the system can provide high-resolution 3D images of vascular structures to depths of up to 5 mm. It is considered that this type of instrument may find a role in the clinical assessment of conditions characterized by changes in the vasculature such as skin tumours and superficial soft tissue damage due to burns, wounds or ulceration. It may also find application in the characterization of small animal cancer models where it is important to follow the tumour vasculature over time in order to study its development and/or response to therapy.

High-frequency spectral ultrasound imaging (SUSI) visualizes early post-traumatic heterotopic ossification (HO) in a mouse model.

PubMed

Ranganathan, Kavitha; Hong, Xiaowei; Cholok, David; Habbouche, Joe; Priest, Caitlin; Breuler, Christopher; Chung, Michael; Li, John; Kaura, Arminder; Hsieh, Hsiao Hsin Sung; Butts, Jonathan; Ucer, Serra; Schwartz, Ean; Buchman, Steven R; Stegemann, Jan P; Deng, Cheri X; Levi, Benjamin

2018-04-01

Early treatment of heterotopic ossification (HO) is currently limited by delayed diagnosis due to limited visualization at early time points. In this study, we validate the use of spectral ultrasound imaging (SUSI) in an animal model to detect HO as early as one week after burn tenotomy. Concurrent SUSI, micro CT, and histology at 1, 2, 4, and 9weeks post-injury were used to follow the progression of HO after an Achilles tenotomy and 30% total body surface area burn (n=3-5 limbs per time point). To compare the use of SUSI in different types of injury models, mice (n=5 per group) underwent either burn/tenotomy or skin incision injury and were imaged using a 55MHz probe on VisualSonics VEVO 770 system at one week post injury to evaluate the ability of SUSI to distinguish between edema and HO. Average acoustic concentration (AAC) and average scatterer diameter (ASD) were calculated for each ultrasound image frame. Micro CT was used to calculate the total volume of HO. Histology was used to confirm bone formation. Using SUSI, HO was visualized as early as 1week after injury. HO was visualized earliest by 4weeks after injury by micro CT. The average acoustic concentration of HO was 33% more than that of the control limb (n=5). Spectroscopic foci of HO present at 1week that persisted throughout all time points correlated with the HO present at 9weeks on micro CT imaging. SUSI visualizes HO as early as one week after injury in an animal model. SUSI represents a new imaging modality with promise for early diagnosis of HO. Copyright © 2018 Elsevier Inc. All rights reserved.

Fire ignition during laser surgery in pet rodents

PubMed Central

2012-01-01

Background Laser surgery is an attractive alternative to other means of section device in terms of tissue inflammation and interaction, which has been extensively used in human and veterinary medicine. Although accidental ignition during laser surgeries is sporadically reported in human medical literature, to the authors’ knowledge this is the first report regarding laser-dependent fire ignition during surgery in veterinary medicine. Case presentation Two rodents, a 13-month old, 27-gram, male pet mouse (Mus musculus) and a 1-year old, female Russian hamster (Phodopus sungorus), underwent surgical removal of masses with diode laser. During the surgical procedures fires ignited from the face masks. The mouse presented severe burns on the head and both forelimbs, it was hospitalized and approximately 2 months after surgery burns were resolved. The hamster presented severe burns on the face and the proximal regions of the body. At 72 hours from the accident the hamster was euthanized. Conclusion The present report suggests that fire ignition is a potential life-threatening complication of laser surgery in non-intubated rodents maintained under volatile anesthesia. High oxygen concentrations, the presence of combustible, and the narrowness of the surgical field with the face mask during laser surgery on rodents are risk factors for fire ignition. PMID:23009047

Experimental COPD induced by solid combustible burn smoke in rats: a study of the emphysematous changes of the pulmonary parenchyma.

PubMed

Murărescu, Elena Doina; Eloae-Zugun, Fl; Mihailovici, Maria Sultana

2008-01-01

According to the GOLD 2006 definition, COPD is a preventable and treatable pathological situation characterized by the partially reversible airflow limitation determined by a variable proportion mixture of small airways disease (obliterative bronchiolitis) and parenchyma destruction (emphysema). A major impediment in the study of the COPD is represented by the fact the fundamental morphological changes that determine the major pulmonary dysfunction take place in the small, peripheral, airways, at the bronchiolo-alveolar attachments. That is why the experimental model of COPD developed progressively to the transgenic mouse. There are many experimental studies on the animal models that have obtained emphysema rapidly through intratraheal instillation of elastasis or bronchitis/bronchiolitis through intratraheal instillation of particles. It is accepted that the unnatural character of aggression, that does not permit the natural evolution of the inflammatory phenomenon, limits these models and tissue remodeling that take place in COPD patients. It is well known that cigarette smoking is a major cause of COPD. There have been reported some cases of COPD in never smoking patients exposed to air pollutants. We aimed to create an experimental model of COPD in rat through exposure to smoke resulted from solid combustibles burn for the same period and in the same conditions of cigarette smoke exposure and to compare the pulmonary morphological changes. Thirty Wistar rats were divided into three groups (n = 10): (1) the control group (C), (2) the cigarette smoke group (CS), and (3) the solid combustible smoke group (SCS). Apart from the control group, these were treated with solid combustibles smoke (SCS group) or cigarette smoke (CS group) for six months. Morphological and morphometry studies have been assessed. We have established a rat COPD model based on natural cigarette smoke exposure versus solid combustible burn resulted smoke, usable for a further approach in human non-smoker COPD investigation. Out procedures resulted in clear pulmonary morphological lesions that are characteristic for COPD. The achieved data support the idea that solid combustible burn resulted smoke determines emphysematous parenchyma lesions that are similar, but with an attenuated morphological appearance when comparing to the cigarette smoke exposure.

The helminth community component species of the wood mouse as biological tags of a ten post-fire-year regeneration process in a Mediterranean ecosystem.

PubMed

Sáez-Durán, Sandra; Debenedetti, Ángela L; Sainz-Elipe, Sandra; Galán-Puchades, M Teresa; Fuentes, Màrius V

2018-05-10

Serra Calderona Natural Park, a Mediterranean ecosystem, has been in post-fire regeneration for 10 years. To elucidate which helminth community component species of the wood mouse, Apodemus sylvaticus, can be considered biological tags of this process, the influence of intrinsic (host density; host sex and age) and extrinsic factors (site, year, and period of capture; vegetation recovery) on their prevalence and abundance has been analysed, comparing a burned and an unburned area. A total of 564 wood mice (408 from the burned and 156 from the unburned area), from the 2nd to the10th post-fire year, was included in this helminthoecological study. The results suggest that the area in post-fire regeneration is still more vulnerable to periodic environmental changes than the unburned area as deduced from the analysis of the helminth populations of Pseudocatenotaenia matovi, Skrjabinotaenia lobata, Trichuris muris, Eucoleus bacillatus and Aonchotheca annulosa. The intermediate and definitive host populations presented a greater variability to these environmental changes in the burned area (Taenia parva, P. matovi, S. lobata, A. annulosa, Syphacia stroma and S. frederici). In the regenerating area, some behavioural changes in certain populations determined by the host sex are taking place (T. parva, Helgimosomoides polygyrus and S. frederici). During the last years studied, a greater similarity in the populational development of some component species between both areas can be appreciated (H. polygyrus and S. stroma). The role of the wood mouse and its helminth parasites as biological tags of the post-fire regeneration process in Mediterranean ecosystems has been confirmed.

A role for long chain myosin light chain kinase (MLCK-210) in microvascular hyperpermeability during severe burns.

PubMed

Reynoso, Rashell; Perrin, Rachel M; Breslin, Jerome W; Daines, Dayle A; Watson, Katherine D; Watterson, D Martin; Wu, Mack H; Yuan, Sarah

2007-11-01

Microvascular leakage has been implicated in the pathogenesis of multiple organ dysfunction during trauma. Previous studies suggest the involvement of myosin light chain (MLC) phosphorylation-triggered endothelial contraction in the development of microvascular hyperpermeability. Myosin light chain kinase (MLCK) plays a key role in the control of MLC-phosphorylation status; thus, it is thought to modulate barrier function through its regulation of intracellular contractile machinery. The aim of this study was to further investigate the endothelial mechanism of MLC-dependent barrier injury in burns, focusing on the long isoform of MLCK (MLCK-210) that has recently been identified as the predominant isoform expressed in vascular endothelial cells. An MLCK-210 knockout mouse model was subjected to third-degree scald burn covering 25% total body surface area. The mesenteric microcirculation was observed using intravital microscopy, and the microvascular permeability was assessed by measuring the transvenular flux of fluorescein isothiocyanate-albumin. In a separate experiment, in vivo mesenteric hydraulic conductivity (Lp) was measured using the modified Landis technique. The injury caused a profound microvascular leakage, as indicated by a 2-fold increase in albumin flux and 4-fold increase in Lp at the early stages, which was associated with a high mortality within the 24-h period. Compared with wild-type control, the MLCK-210-deficient mice displayed a significantly improved survival with a greatly attenuated microvascular hyperpermeability response to albumin and fluid. These results provide direct evidence for a role of MLCK-210 in mediating burn-induced microvascular barrier injury and validate MLCK-210 as a potential therapeutic target in the treatment of burn edema.

JAK/STAT3 and Smad3 activities are required for the wound healing properties of Periplaneta americana extracts.

PubMed

Song, Qin; Xie, Yuxin; Gou, Qiheng; Guo, Xiaoqiang; Yao, Qian; Gou, Xiaojun

2017-08-01

Periplaneta americana extracts (PAEs) play a crucial role in skin wound healing. However, their molecular effects and signaling pathways in regenerating tissues and cells are not clear. In this study, we refined the PAE from Periplaneta americana to investigate the mechanisms underlying skin wound healing. The human keratinocyte line HaCaT was selected and a mouse model of deep second-degree thermal burn was established for in vitro and in vivo studies, respectively. PAE treatment induced the proliferation and migration of HaCaT cells and wound healing in the burn model. Furthermore, the effects of PAE on wound healing were found to depend on the Janus-activated kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway and Smad3 activities, according to western blot analysis and immunohistochemical (IHC) assays in vitro and in vivo. Pretreatment with a STAT3 inhibitor blocked the cell proliferation and migration induced by PAE. The results indicate the wound-healing function of PAE via enhanced JAK/STAT3 signaling and Smad3 activities. Our studies provide a theoretical basis underlying the role of PAE in cutaneous wound healing.

Surfactant Dysfunction in ARDS and Bronchiolitis is Repaired with Cyclodextrins.

PubMed

Al-Saiedy, Mustafa; Gunasekara, Lasantha; Green, Francis; Pratt, Ryan; Chiu, Andrea; Yang, Ailian; Dennis, John; Pieron, Cora; Bjornson, Candice; Winston, Brent; Amrein, Matthias

2018-03-01

Acute respiratory distress syndrome (ARDS) is caused by many factors including inhalation of toxicants, acute barotrauma, acid aspiration, and burns. Surfactant function is impaired in ARDS and acute airway injury resulting in high surface tension with alveolar and small airway collapse, edema, hypoxemia, and death. In this study, we explore the mechanisms whereby surfactant becomes dysfunctional in ARDS and bronchiolitis and its repair with a cyclodextrin drug that sequesters cholesterol. We used in vitro model systems, a mouse model of ARDS, and samples from patients with acute bronchiolitis. Surface tension was measured by captive bubble surfactometry. Patient samples showed severe surfactant inhibition even in the absence of elevated cholesterol levels. Surfactant was also impaired in ARDS mice where the cholesterol to phospholipid ratio (W/W%) was increased. Methyl-β-cyclodextrin (MβCD) restored surfactant function to normal in both human and animal samples. Model studies showed that the inhibition of surfactant was due to both elevated cholesterol and an interaction between cholesterol and oxidized phospholipids. MβCD was also shown to have anti-inflammatory effects. Inhaled cyclodextrins have potential for the treatment of ARDS. They could be delivered in a portable device carried in combat and used following exposure to toxic gases and fumes or shock secondary to hemorrhage and burns.

Lipid-induced mitochondrial stress and insulin action in muscle

PubMed Central

Muoio, Deborah M.; Neufer, P. Darrell

2012-01-01

Summary The interplay between mitochondrial energetics, lipid balance and muscle insulin sensitivity has remained a topic of intense interest and debate for decades. One popular view suggests that increased oxidative capacity benefits metabolic wellness; based on the premise that it is healthier to burn fat than glucose. Attempts to test this hypothesis using genetically-modified mouse models have produced contradictory results; and instead link muscle insulin resistance to excessive fat oxidation, acylcarnitine production and increased mitochondrial H2O2 emitting potential. Here, we consider emerging evidence that insulin action in muscle is driven principally by mitochondrial load and redox signaling rather than oxidative capacity. PMID:22560212

Comparing the reported burn conditions for different severity burns in porcine models: a systematic review.

PubMed

Andrews, Christine J; Cuttle, Leila

2017-12-01

There are many porcine burn models that create burns using different materials (e.g. metal, water) and different burn conditions (e.g. temperature and duration of exposure). This review aims to determine whether a pooled analysis of these studies can provide insight into the burn materials and conditions required to create burns of a specific severity. A systematic review of 42 porcine burn studies describing the depth of burn injury with histological evaluation is presented. Inclusion criteria included thermal burns, burns created with a novel method or material, histological evaluation within 7 days post-burn and method for depth of injury assessment specified. Conditions causing deep dermal scald burns compared to contact burns of equivalent severity were disparate, with lower temperatures and shorter durations reported for scald burns (83°C for 14 seconds) compared to contact burns (111°C for 23 seconds). A valuable archive of the different mechanisms and materials used for porcine burn models is presented to aid design and optimisation of future models. Significantly, this review demonstrates the effect of the mechanism of injury on burn severity and that caution is recommended when burn conditions established by porcine contact burn models are used by regulators to guide scald burn prevention strategies. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Burns - resources

MedlinePlus

Resources - burns ... The following organizations are good resources for information on burns : Burns Recovered -- brsg.org Model Systems Knowledge Translation Center - Burn Model Systems -- www.msktc.org/burn http:// ...

Lipid-induced mitochondrial stress and insulin action in muscle.

PubMed

Muoio, Deborah M; Neufer, P Darrell

2012-05-02

The interplay between mitochondrial energetics, lipid balance, and muscle insulin sensitivity has remained a topic of intense interest and debate for decades. One popular view suggests that increased oxidative capacity benefits metabolic wellness, based on the premise that it is healthier to burn fat than glucose. Attempts to test this hypothesis using genetically modified mouse models have produced contradictory results and instead link muscle insulin resistance to excessive fat oxidation, acylcarnitine production, and increased mitochondrial H(2)O(2)-emitting potential. Here, we consider emerging evidence that insulin action in muscle is driven principally by mitochondrial load and redox signaling rather than oxidative capacity. Copyright © 2012 Elsevier Inc. All rights reserved.

A novel immune competent murine hypertrophic scar contracture model: A tool to elucidate disease mechanism and develop new therapies

PubMed Central

Ibrahim, Mohamed Magdy; Bond, Jennifer; Bergeron, Andrew; Miller, Kyle J; Ehanire, Tosan; Quiles, Carlos; Lorden, Elizabeth R; Medina, Manuel A; Fisher, Mark; Klitzman, Bruce; Selim, M Angelica; Leong, Kam W; Levinson, Howard

2014-01-01

Hypertrophic scar (HSc) contraction following burn injury causes contractures. Contractures are painful and disfiguring. Current therapies are marginally effective. To study pathogenesis and develop new therapies, a murine model is needed. We have created a validated immune-competent murine HSc model. A third-degree burn was created on dorsum of C57BL/6 mice. Three days postburn, tissue was excised and grafted with ear skin. Graft contraction was analyzed and tissue harvested on different time points. Outcomes were compared with human condition to validate the model. To confirm graft survival, green fluorescent protein (GFP) mice were used, and histologic analysis was performed to differentiate between ear and back skin. Role of panniculus carnosus in contraction was analyzed. Cellularity was assessed with 4′,6-diamidino-2-phenylindole. Collagen maturation was assessed with Picro-sirius red. Mast cells were stained with Toluidine blue. Macrophages were detected with F4/80 immune. Vascularity was assessed with CD31 immune. RNA for contractile proteins was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Elastic moduli of skin and scar tissue were analyzed using a microstrain analyzer. Grafts contracted to ∼45% of their original size by day 14 and maintained their size. Grafting of GFP mouse skin onto wild-type mice, and analysis of dermal thickness and hair follicle density, confirmed graft survival. Interestingly, hair follicles disappeared after grafting and regenerated in ear skin configuration by day 30. Radiological analysis revealed that panniculus carnosus doesn't contribute to contraction. Microscopic analyses showed that grafts show increase in cellularity. Granulation tissue formed after day 3. Collagen analysis revealed increases in collagen maturation over time. CD31 stain revealed increased vascularity. Macrophages and mast cells were increased. qRT-PCR showed up-regulation of transforming growth factor beta, alpha smooth muscle actin, and rho-associated protein kinase 2 in HSc. Tensile testing revealed that human skin and scar tissues are tougher than mouse skin and scar tissues. PMID:25327261

The organisation of critical care for burn patients in the UK: epidemiology and comparison of mortality prediction models.

PubMed

Toft-Petersen, A P; Ferrando-Vivas, P; Harrison, D A; Dunn, K; Rowan, K M

2018-05-15

In the UK, a network of specialist centres has been set up to provide critical care for burn patients. However, some burn patients are admitted to general intensive care units. Little is known about the casemix of these patients and how it compares with patients in specialist burn centres. It is not known whether burn-specific or generic risk prediction models perform better when applied to patients managed in intensive care units. We examined admissions for burns in the Case Mix Programme Database from April 2010 to March 2016. The casemix, activity and outcome in general and specialist burn intensive care units were compared and the fit of two burn-specific risk prediction models (revised Baux and Belgian Outcome in Burn Injury models) and one generic model (Intensive Care National Audit and Research Centre model) were compared. Patients in burn intensive care units had more extensive injuries compared with patients in general intensive care units (median (IQR [range]) burn surface area 16 (7-32 [0-98])% vs. 8 (1-18 [0-100])%, respectively) but in-hospital mortality was similar (22.8% vs. 19.0%, respectively). The discrimination and calibration of the generic Intensive Care National Audit and Research Centre model was superior to the revised Baux and Belgian Outcome in Burn Injury burn-specific models for patients managed on both specialist burn and general intensive care units. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

A Computer Program to Evaluate Experimental Therapies for Treating Burned Patients

PubMed Central

Flora, Jairus D.; Flora, Sharyl Ann

1980-01-01

Determining the worth of new therapies for burn patients has been difficult because of the rarity of the burn injury and the disparate survival chances associated with different sizes of burns. Recently a burn survival model has been developed that estimates the risk of death from a burn as a function of the patient's age, sex, area of full thickness (third degree) burn, area of partial thickness burn, involvement of the perineum, and time from burn to admission. An alternative risk model uses the total area burned in place of the areas of partial thickness burn and full thickness burn, and is appropriate if the amount of full thickness burn is not determined accurately. This paper describes a program that uses these risk models to correct or standardize for demographic and severity factors, then, after that adjustment, tests whether a group of burn patients who received a new or experimental therapy shows a significantly better survival rate than that predicted by a baseline model. The program is a simple one written in Fortran for easy adaptation to other computer systems.

Substance P Antagonist CP-96345 Blocks Lung Vascular Leakage and Inflammation More Effectively than its Stereoisomer CP-96344 in a Mouse Model of Smoke Inhalation and Burn Injury

PubMed Central

Jacob, Sam; Deyo, Donald J.; Cox, Robert A.; Jacob, Reuben K; Herndon, David N.; Traber, Daniel L.; Hawkins, Hal K.

2010-01-01

The recently developed murine model of smoke inhalation and burn (SB) injury was used to study the effect of the substance-P antagonist CP96345. C57BL/6 mice were pretreated with an i.v. dose of a specific NK-1 receptor antagonist, CP9635, or its inactive enantiomer, CP96344, (10 mg/Kg) 1 hr prior to SB injury per protocol (n = 5). Mice were anesthetized and exposed to cooled cotton smoke, 2X 30 sec, followed by a 40% total body surface area flame burn per protocol. At 48 hr after SB injury Evans Blue (EB) dye and myeloperoxidase (MPO) were measured in lung after vascular perfusion. Lungs were also analyzed for hemoglobin (Hb) and wet/dry weight ratio. In the current study, CP96345 pretreatment caused a significant decrease in wet/dry weight ratio (23%, *p = 0.048), EB (31%, *p = 0.047), Hb (46%, *p = 0.002) and MPO (54%, *p = 0.037) levels following SB injury compared to animals with SB injury alone. CP-96344 pretreatment caused an insignificant decrease in wet/dry weight ratio (14%, p=0.18), EB (16%, p = 0.134), Hb (9%, p = 0.39) and an insignificant increase in MPO (4%, p =0.79) as compared to mice that received SB injury alone. As expected, levels of EB, Hb, MPO, and wet/dry weight ratios were all significantly (p < 0.05) increased 48 hr following SB injury alone compared to respective sham animals. In conclusion, the current study indicates that pretreatment with specific NK-1R antagonist CP-96345 attenuates the lung injury and inflammation induced by SB injury in mice. PMID:20201741

Patient experiences of burn scars in adults and children and development of a health-related quality of life conceptual model: A qualitative study.

PubMed

Simons, Megan; Price, Nathaniel; Kimble, Roy; Tyack, Zephanie

2016-05-01

The aim of this study was to understand the impact of burn scars on health-related quality of life (HRQOL) from the perspective of adults and children with burn scars, and caregivers to inform the development of a conceptual model of burn scar HRQOL. Twenty-one participants (adults and children) with burn scars and nine caregivers participated in semi-structured, face-to-face interviews between 2012 and 2013. During the interviews, participants were asked to describe features about their (or their child's) burn scars and its impact on everyday life. Two coders conducted thematic analysis, with consensus achieved through discussion and review with a third coder. The literature on HRQOL models was then reviewed to further inform the development of a conceptual model of burn scar HRQOL. Five themes emerged from the qualitative data: 'physical and sensory symptoms', 'impact of burn scar interventions', 'impact of burn scar symptoms', 'personal factors' and 'change over time'. Caregivers offered further insights into family functioning after burn, and the impacts of burn scars and burn scar interventions on family life. In the conceptual model, symptoms (sensory and physical) of burn scars are considered proximal to HRQOL, with distal indicators including functioning (physical, emotional, social, cognitive), individual factors and the environment. Overall quality of life was affected by HRQOL. Understanding the impact of burn scars on HRQOL and the development of a conceptual model will inform future burn scar research and clinical practice. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Cutaneous challenge with chemical warfare agents in the SKH-1 hairless mouse. (I) Development of a model for screening studies in skin decontamination and protection.

PubMed

Dorandeu, F; Taysse, L; Boudry, I; Foquin, A; Hérodin, F; Mathieu, J; Daulon, S; Cruz, C; Lallement, G

2011-06-01

Exposure to lethal chemical warfare agents (CWAs) is no longer only a military issue due to the terrorist threat. Among the CWAs of concern are the organophosphorus nerve agent O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX) and the vesicant sulfur mustard (SM). Although efficient means of decontamination are available, most of them lose their efficacy when decontamination is delayed after exposure of the bare skin. Alternatively, CWA skin penetration can be prevented by topical skin protectants. Active research in skin protection and decontamination is thus paramount. In vivo screening of decontaminants or skin protectants is usually time consuming and may be expensive depending on the animal species used. We were thus looking for a suitable, scientifically sound and cost-effective model, which is easy to handle. The euthymic hairless mouse Crl: SKH-1 (hr/hr) BR is widely used in some skin studies and has previously been described to be suitable for some experiments involving SM or SM analogs. To evaluate the response of this species, we studied the consequences of exposing male anaesthetized SKH-1 mice to either liquid VX or to SM, the latter being used in liquid form or as saturated vapours. Long-term effects of SM burn were also evaluated. The model was then used in the companion paper (Taysse et al.(1)).

Effects of burn location and investigator on burn depth in a porcine model.

PubMed

Singer, Adam J; Toussaint, Jimmy; Chung, Won Taek; Thode, Henry C; McClain, Steve; Raut, Vivek

2016-02-01

In order to be useful, animal models should be reproducible and consistent regardless of sampling bias, investigator creating burn, and burn location. We determined the variability in burn depth based on biopsy location, burn location and investigator in a porcine model of partial thickness burns. 24 partial thickness burns (2.5 cm by 2.5 cm each) were created on the backs of 2 anesthetized pigs by 2 investigators (one experienced, one inexperienced) using a previously validated model. In one of the pigs, the necrotic epidermis covering each burn was removed. Five full thickness 4mm punch biopsies were obtained 1h after injury from the four corners and center of the burns and stained with Hematoxylin and Eosin and Masson's trichrome for determination of burn depth by a board certified dermatopathologist blinded to burn location and investigator. Comparisons of burn depth by biopsy location, burn location and investigator were performed with t-tests and ANOVA as appropriate. The mean (SD) depth of injury to blood vessels (the main determinant of burn progression) in debrided and non-debrided pigs pooled together was 1.8 (0.3)mm, which included 75% of the dermal depth. Non-debrided burns were 0.24 mm deeper than debrided burns (P<0.001). Burn depth increased marginally from cephalic to caudal in non-debrided burns, but showed no statistical differences for these locations, in debrided burns. Additionally, there were also no statistical differences in burn depths from midline to lateral in either of these burn types. Burn depth was similar for both investigators and among biopsy locations. Burn depth was greater for caudal locations in non-debrided burns and overall non-debrided burns were deeper than debrided burns. However, burn depth did not differ based on investigator, biopsy site, and medial-lateral location. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Reacting Chemistry Based Burn Model for Explosive Hydrocodes

NASA Astrophysics Data System (ADS)

Schwaab, Matthew; Greendyke, Robert; Steward, Bryan

2017-06-01

Currently, in hydrocodes designed to simulate explosive material undergoing shock-induced ignition, the state of the art is to use one of numerous reaction burn rate models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these models are largely based on empirical data and must be recalibrated for every new material being simulated. We propose that the use of an equilibrium Arrhenius rate reacting chemistry model in place of these empirically derived burn models will improve the accuracy for these computational codes. Such models have been successfully used in codes simulating the flow physics around hypersonic vehicles. A reacting chemistry model of this form was developed for the cyclic nitramine RDX by the Naval Research Laboratory (NRL). Initial implementation of this chemistry based burn model has been conducted on the Air Force Research Laboratory's MPEXS multi-phase continuum hydrocode. In its present form, the burn rate is based on the destruction rate of RDX from NRL's chemistry model. Early results using the chemistry based burn model show promise in capturing deflagration to detonation features more accurately in continuum hydrocodes than previously achieved using empirically derived burn models.

Development of a Consistent and Reproducible Porcine Scald Burn Model

PubMed Central

Kempf, Margit; Kimble, Roy; Cuttle, Leila

2016-01-01

There are very few porcine burn models that replicate scald injuries similar to those encountered by children. We have developed a robust porcine burn model capable of creating reproducible scald burns for a wide range of burn conditions. The study was conducted with juvenile Large White pigs, creating replicates of burn combinations; 50°C for 1, 2, 5 and 10 minutes and 60°C, 70°C, 80°C and 90°C for 5 seconds. Visual wound examination, biopsies and Laser Doppler Imaging were performed at 1, 24 hours and at 3 and 7 days post-burn. A consistent water temperature was maintained within the scald device for long durations (49.8 ± 0.1°C when set at 50°C). The macroscopic and histologic appearance was consistent between replicates of burn conditions. For 50°C water, 10 minute duration burns showed significantly deeper tissue injury than all shorter durations at 24 hours post-burn (p ≤ 0.0001), with damage seen to increase until day 3 post-burn. For 5 second duration burns, by day 7 post-burn the 80°C and 90°C scalds had damage detected significantly deeper in the tissue than the 70°C scalds (p ≤ 0.001). A reliable and safe model of porcine scald burn injury has been successfully developed. The novel apparatus with continually refreshed water improves consistency of scald creation for long exposure times. This model allows the pathophysiology of scald burn wound creation and progression to be examined. PMID:27612153

Immunological control of methicillin-resistant Staphylococcus aureus (MRSA) infection in an immunodeficient murine model of thermal injuries

PubMed Central

Katakura, T; Yoshida, T; Kobayashi, M; Herndon, D N; Suzuki, F

2005-01-01

Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA), is a major cause of sepsis in patients who are immunosuppressed by their burns. In this study, an immunological regulation of MRSA infection was attempted in a mouse model of thermal injury. SCIDbg mice were resistant to MRSA infection, while SCIDbgMN mice (SCIDbg mice depleted of neutrophils and macrophages (Mφ)) were susceptible to the same infection. Also, thermally injured SCIDbg mice were shown to be susceptible to MRSA infection. On the other hand, the resistance of SCIDbgMN mice to the infection was completely recovered after an inoculation with Mφ from normal mice. However, anti-MRSA resistance was not shown in SCIDbgMN mice inoculated with Mφ from thermally injured mice. Mφ from MRSA-infected thermally injured mice were identified as alternatively activated Mφ, and Mφ from MRSA-infected unburned mice were characterized as classically activated Mφ. Mφ from thermally injured SCIDbg mice previously treated with 2-carboxyethylgermanium sesquioxide (Ge-132) protected SCIDbgMN mice against MRSA infection. Ge-132 has been described as an inhibitor of alternatively activated Mφ generation. These results suggest that MRSA infection in thermally injured patients is controlled immunologically through the induction of anti-MRSA effector cells and elimination of burn-associated alternatively activated Mφ, which are cells that inhibit the generation of classically activated Mφ. PMID:16297152

KERIS: kaleidoscope of gene responses to inflammation between species

PubMed Central

Li, Peng; Tompkins, Ronald G; Xiao, Wenzhong

2017-01-01

A cornerstone of modern biomedical research is the use of animal models to study disease mechanisms and to develop new therapeutic approaches. In order to help the research community to better explore the similarities and differences of genomic response between human inflammatory diseases and murine models, we developed KERIS: kaleidoscope of gene responses to inflammation between species (available at http://www.igenomed.org/keris/). As of June 2016, KERIS includes comparisons of the genomic response of six human inflammatory diseases (burns, trauma, infection, sepsis, endotoxin and acute respiratory distress syndrome) and matched mouse models, using 2257 curated samples from the Inflammation and the Host Response to Injury Glue Grant studies and other representative studies in Gene Expression Omnibus. A researcher can browse, query, visualize and compare the response patterns of genes, pathways and functional modules across different diseases and corresponding murine models. The database is expected to help biologists choosing models when studying the mechanisms of particular genes and pathways in a disease and prioritizing the translation of findings from disease models into clinical studies. PMID:27789704

Quantifying soil burn severity for hydrologic modeling to assess post-fire effects on sediment delivery

NASA Astrophysics Data System (ADS)

Dobre, Mariana; Brooks, Erin; Lew, Roger; Kolden, Crystal; Quinn, Dylan; Elliot, William; Robichaud, Pete

2017-04-01

Soil erosion is a secondary fire effect with great implications for many ecosystem resources. Depending on the burn severity, topography, and the weather immediately after the fire, soil erosion can impact municipal water supplies, degrade water quality, and reduce reservoirs' storage capacity. Scientists and managers use field and remotely sensed data to quickly assess post-fire burn severity in ecologically-sensitive areas. From these assessments, mitigation activities are implemented to minimize post-fire flood and soil erosion and to facilitate post-fire vegetation recovery. Alternatively, land managers can use fire behavior and spread models (e.g. FlamMap, FARSITE, FOFEM, or CONSUME) to identify sensitive areas a priori, and apply strategies such as fuel reduction treatments to proactively minimize the risk of wildfire spread and increased burn severity. There is a growing interest in linking fire behavior and spread models with hydrology-based soil erosion models to provide site-specific assessment of mitigation treatments on post-fire runoff and erosion. The challenge remains, however, that many burn severity mapping and modeling products quantify vegetation loss rather than measuring soil burn severity. Wildfire burn severity is spatially heterogeneous and depends on the pre-fire vegetation cover, fuel load, topography, and weather. Severities also differ depending on the variable of interest (e.g. soil, vegetation). In the United States, Burned Area Reflectance Classification (BARC) maps, derived from Landsat satellite images, are used as an initial burn severity assessment. BARC maps are classified from either a Normalized Burn Ratio (NBR) or differenced Normalized Burned Ratio (dNBR) scene into four classes (Unburned, Low, Moderate, and High severity). The development of soil burn severity maps requires further manual field validation efforts to transform the BARC maps into a product more applicable for post-fire soil rehabilitation activities. Alternative spectral indices and modeled output approaches may prove better predictors of soil burn severity and hydrologic effects, but these have not yet been assessed in a model framework. In this project we compare field-verified soil burn severity maps to satellite-derived and modeled burn severity maps. We quantify the extent to which there are systematic differences in these mapping products. We then use the Water Erosion Prediction Project (WEPP) hydrologic soil erosion model to assess sediment delivery from these fires using the predicted and observed soil burn severity maps. Finally, we discuss differences in observed and predicted soil burn severity maps and application to watersheds in the Pacific Northwest to estimate post-fire sediment delivery.

Sources, Transport, and Climate Impacts of Biomass Burning Aerosols

NASA Technical Reports Server (NTRS)

Chin, Mian

2010-01-01

In this presentation, I will first talk about fundamentals of modeling of biomass burning emissions of aerosols, then show the results of GOCART model simulated biomass burning aerosols. I will compare the model results with observations of satellite and ground-based network in terms of total aerosol optical depth, aerosol absorption optical depth, and vertical distributions. Finally the long-range transport of biomass burning aerosols and the climate effects will be addressed. I will also discuss the uncertainties associated with modeling and observations of biomass burning aerosols

Biomass Burning Data and Information

Atmospheric Science Data Center

2015-04-21

Biomass Burning Data and Information This data set represents ... geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ... models of the atmosphere. Project Title:  Biomass Burning Discipline:  Tropospheric Composition ...

Contributions of Kansas rangeland burning to ambient O3: Analysis of data from 2001 to 2016.

PubMed

Liu, Zifei; Liu, Yang; Murphy, James P; Maghirang, Ronaldo

2018-03-15

Prescribed range/pasture burning is a common practice in Kansas to enhance the nutritional value of native grasses and control invading weeds, trees, and brush. A major concern associated with the burning is the contribution of smoke to elevated ground level ambient ozone (O 3 ). The objective of this study is to estimate contributions of Kansas rangeland burning to ambient O 3 mixing ratios through regression analysis (1) between observed O 3 data and available satellite burn activity data from 2001 to 2016; and (2) between observed O 3 data and the smoke contributions to PM 2.5 which were resolved from receptor modeling. Positive correlations were observed between ambient O 3 levels and the acres burned each year estimated from satellite imagery. When burned acres in April were larger than or equal to 1.9 million, O 3 >70ppb occurred at least at one of the ten monitoring sites in Kansas. Statistical regression models of daily maximum 8-hour O 3 mixing ratios were developed at each of the ten monitoring sites using meteorological predictors. The O 3 model residuals that were not explained by the meteorological effect models were affected by PM 2.5 contributors including sulfate/industrial sources and emissions that generated secondary organic particles, such as rangeland burning, which were derived from receptor modeling. The average O 3 model residual on the high O 3 days in April was 21±9ppb, which was likely associated with smoke emissions from burning. Research will continue to obtain daily satellite burn activity data and to correlate burn data with daily O 3 data, so that modeling of O 3 levels can be improved under influences of daily burn activities. Less frequency of high O 3 days was observed in April since 2011, which may be partly due to implementation of the Flint Hills Smoke Management Plan which promoted better timing of burns. Copyright © 2017 Elsevier B.V. All rights reserved.

Pulse duration determines levels of Hsp70 induction in tissues following laser irradiation

NASA Astrophysics Data System (ADS)

Mackanos, Mark A.; Contag, Christopher H.

2011-07-01

Induction of heat shock protein (Hsp) expression correlates with cytoprotection, reduced tissue damage, and accelerated healing in animal models. Since Hsps are transcriptionally activated in response to stress, they can act as stress indicators in burn injury or surgical procedures that produce heat and thermal change. A fast in vivo readout for induction of Hsp transcription in tissues would allow for the study of these proteins as therapeutic effect mediators and reporters of thermal stress/damage. We used a transgenic reporter mouse in which a luciferase expression is controlled by the regulatory region of the inducible 70 kilodalton (kDa) Hsp as a rapid readout of cellular responses to laser-mediated thermal stress/injury in mouse skin. We assessed the pulse duration dependence of the Hsp70 expression after irradiation with a CO2 laser at 10.6 μm in wavelength over a range of 1000 to 1 ms. Hsp70 induction varied with changes in laser pulse durations and radiant exposures, which defined the ranges at which thermal activation of Hsp70 can be used to protect cells from subsequent stress, and reveals the window of thermal stress that tissues can endure.

Retinoic Acid Engineered Amniotic Membrane Used as Graft or Homogenate: Positive Effects on Corneal Alkali Burns.

PubMed

Joubert, Romain; Daniel, Estelle; Bonnin, Nicolas; Comptour, Aurélie; Gross, Christelle; Belville, Corinne; Chiambaretta, Frédéric; Blanchon, Loïc; Sapin, Vincent

2017-07-01

Alkali burns are the most common, severe chemical ocular injuries, their functional prognosis depending on corneal wound healing efficiency. The purpose of our study was to compare the benefits of amniotic membrane (AM) grafts and homogenates for wound healing in the presence or absence of previous all-trans retinoic acid (atRA) treatment. Fifty male CD1 mice with reproducible corneal chemical burn were divided into five groups, as follows: group 1 was treated with saline solution; groups 2 and 3 received untreated AM grafts or grafts treated with atRA, respectively; and groups 4 and 5 received untreated AM homogenates or homogenates treated with atRA, respectively. After 7 days of treatment, ulcer area and depth were measured, and vascular endothelial growth factor (VEGF) and matrix metalloproteinase 9 (MMP-9) were quantified. AM induction by atRA was confirmed via quantification of retinoic acid receptor β (RARβ), a well-established retinoic acid-induced gene. Significant improvements of corneal wound healing in terms of ulcer area and depth were obtained with both strategies. No major differences were found between the efficiency of AM homogenates and grafts. This positive action was increased when AM was pretreated with atRA. Furthermore, AM induced a decrease in VEGF and MMP-9 levels during the wound healing process. The atRA treatment led to an even greater decrease in the expression of both proteins. Amnion homogenate is as effective as AM grafts in promoting corneal wound healing in a mouse model. A higher positive effect was obtained with atRA treatment.

Influence of phytochemicals in piper betle linn leaf extract on wound healing.

PubMed

Lien, Le Thi; Tho, Nguyen Thi; Ha, Do Minh; Hang, Pham Luong; Nghia, Phan Tuan; Thang, Nguyen Dinh

2015-01-01

Wound healing has being extensively investigated over the world. Healing impairment is caused by many reasons including increasing of free-radicals-mediated damage, delaying in granulation tissue formation, reducing in angiogenesis and decreasing in collagen reorganization. These facts consequently lead to chronic wound healing. Piper betle Linn (Betle) leaves have been folklore used as an ingredient of drugs for cutaneous wound treatment. However, the effect of betle leaf on wound healing is not yet well elucidated. In this study, we aimed to investigate the healing efficacy of methanol leaf extract of Piper betle Linn on proliferation of fibroblast NIH3T3 cells as well as full-thickness burn and excision wounds in swiss mice. Scratch wound healing assays were conducted to examine the effects of betle leaf extract on healing activity of fibroblast cells. Burn and excision wounds on swiss mouse skins were created for investigating the wound healing progress caused by the betle leaf extract. Malondialdehyde (MDA) was also evaluated to examine the products of lipid hydroperoxide (LPO) under conditions of with or without betle leaf extract treatment. The results of this study showed that Piper betle Linn leaf extract in methanol increased proliferation of NIH3T3 cells and promoted wound healing in vitro and in vivo with both burn wound and excision wound models. In addition, this extract significant decreased level of malondialdehyde (MDA) in liver of treated-mice compared with that in non-treated mice. Our results suggest that Piper betle Linn can be used as an ingredient in developing natural origin drugs for treatment of cutaneous wounds.

Scar formation following excisional and burn injuries in a red Duroc pig model.

PubMed

Blackstone, Britani N; Kim, Jayne Y; McFarland, Kevin L; Sen, Chandan K; Supp, Dorothy M; Bailey, J Kevin; Powell, Heather M

2017-08-01

Scar research is challenging because rodents do not naturally form excessive scars, and burn depth, size, and location cannot be controlled in human longitudinal studies. The female, red Duroc pig model has been shown to form robust scars with biological and anatomical similarities to human hypertrophic scars. To more closely mimic the mode of injury, recreate the complex chemical milieu of the burn wound environment and enhance scar development, an animal model of excessive burn-induced scarring was developed and compared with the more commonly used model, which involves excisional wounds created via dermatome. Standardized, full-thickness thermal wounds were created on the dorsum of female, red Duroc pigs. Wounds for the dermatome model were created using two different total dermatome settings: ∼1.5 mm and ≥ 1.9 mm. Results from analysis over 150 days showed that burn wounds healed at much slower rate and contracted more significantly than dermatome wounds of both settings. The burn scars were hairless, had mixed pigmentation, and displayed fourfold and twofold greater excess erythema values, respectively, compared with ∼1.5 mm and ≥ 1.9 mm deep dermatome injuries. Burn scars were less elastic, less pliable, and weaker than scars resulting from excisional injuries. Decorin and versican gene expression levels were elevated in the burn group at day 150 compared with both dermatome groups. In addition, transforming growth factor-beta 1 was significantly up-regulated in the burn group vs. the ∼1.5 mm deep dermatome group at all time points, and expression remained significantly elevated vs. both dermatome groups at day 150. Compared with scars from dermatome wounds, the burn scar model described here demonstrates greater similarity to human hypertrophic scar. Thus, this burn scar model may provide an improved platform for studying the pathophysiology of burn-related hypertrophic scarring, investigating current anti-scar therapies, and development of new strategies with greater clinical benefit. © 2017 by the Wound Healing Society.

Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model.

PubMed

Dong, Xianglin; Xu, Tao; Ma, Shaolin; Wen, Hao

2015-06-01

The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues.

Expression and activity levels of chymase in mast cells of burn wound tissues increase during the healing process in a hamster model

PubMed Central

DONG, XIANGLIN; XU, TAO; MA, SHAOLIN; WEN, HAO

2015-01-01

The present study aimed to investigate the changes in the expression levels and activity of mast cell chymase in the process of burn wound healing in a hamster model of deep second-degree burn. The hamster model was established by exposing a ~3 cm diameter area of bare skin to hot water (75°C) for 0, 6, 8, 10 or 12 sec. Tissue specimens were collected 24 h after burning and histological analysis revealed that hot water contact for 12 sec was required to produce a deep second-degree burn. Quantitative polymerase chain reaction and a radioimmunoassay were used to the determine changes in chymase mRNA expression levels and activity. The mRNA expression levels and activity of chymase were increased in the burn wound tissues when compared with the normal skin. However, no statistically significant differences were observed in mast cell chymase activity amongst the various post-burn stages. Chymase mRNA expression levels peaked at day 1 post-burn, subsequently decreasing at days 3 and 7 post-burn and finally increasing again at day 14 post-burn. In summary, a hamster model of deep second-degree burn can be created by bringing the skin into contact with water at 75°C for 12 sec. Furthermore, the mRNA expression levels and activity of chymase in the burn wound tissues increased when compared with those in normal skin tissues. PMID:26136958

Using Logistic Regression to Predict the Probability of Debris Flows in Areas Burned by Wildfires, Southern California, 2003-2006

USGS Publications Warehouse

Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.; Michael, John A.; Helsel, Dennis R.

2008-01-01

Logistic regression was used to develop statistical models that can be used to predict the probability of debris flows in areas recently burned by wildfires by using data from 14 wildfires that burned in southern California during 2003-2006. Twenty-eight independent variables describing the basin morphology, burn severity, rainfall, and soil properties of 306 drainage basins located within those burned areas were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows soon after the 2003 to 2006 fires were delineated from data in the National Elevation Dataset using a geographic information system; (2) Data describing the basin morphology, burn severity, rainfall, and soil properties were compiled for each basin. These data were then input to a statistics software package for analysis using logistic regression; and (3) Relations between the occurrence or absence of debris flows and the basin morphology, burn severity, rainfall, and soil properties were evaluated, and five multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combinations produced the most effective models, and the multivariate models that best predicted the occurrence of debris flows were identified. Percentage of high burn severity and 3-hour peak rainfall intensity were significant variables in all models. Soil organic matter content and soil clay content were significant variables in all models except Model 5. Soil slope was a significant variable in all models except Model 4. The most suitable model can be selected from these five models on the basis of the availability of independent variables in the particular area of interest and field checking of probability maps. The multivariate logistic regression models can be entered into a geographic information system, and maps showing the probability of debris flows can be constructed in recently burned areas of southern California. This study demonstrates that logistic regression is a valuable tool for developing models that predict the probability of debris flows occurring in recently burned landscapes.

Development of Erosive Burning Models for CFD Predictions of Solid Rocket Motor Internal Environments

NASA Technical Reports Server (NTRS)

Wang, Qun-Zhen

2003-01-01

Four erosive burning models, equations (11) to (14). are developed in this work by using a power law relationship to correlate (1) the erosive burning ratio and the local velocity gradient at propellant surfaces; (2) the erosive burning ratio and the velocity gradient divided by centerline velocity; (3) the erosive burning difference and the local velocity gradient at propellant surfaces; and (4) the erosive burning difference and the velocity gradient divided by centerline velocity. These models depend on the local velocity gradient at the propellant surface (or the velocity gradient divided by centerline velocity) only and, unlike other empirical models, are independent of the motor size. It was argued that, since the erosive burning is a local phenomenon occurring near the surface of the solid propellant, the erosive burning ratio should be independent of the bore diameter if it is correlated with some local flow parameters such as the velocity gradient at the propellant surface. This seems to be true considering the good results obtained by applying these models, which are developed from the small size 5 inch CP tandem motor testing, to CFD simulations of much bigger motors.

Early anticoagulation therapy for severe burns complicated by inhalation injury in a rabbit model

PubMed Central

Fu, Zhong-Hua; Guo, Guang-Hua; Xiong, Zhen-Fang; Liao, Xincheng; Liu, Ming-Zhuo; Luo, Jinhua

2017-01-01

The aim of the present study was to determine the effects of early anticoagulation treatment on severe burns complicated by inhalation injury in a rabbit model. Under anesthetization, an electrical burns instrument (100°C) was used to scald the backs of rabbits for 15 sec, which established a 30% III severe burns model. Treatment of the rabbits with early anticoagulation effectively improved the severe burns complicated by inhalation injury-induced lung injury, reduced PaO2, PaCO2 and SPO2 levels, suppressed the expression of tumor necrosis factor-α, interleukin (IL)-1β and IL-6, and increased the activity of IL-10. In addition, it was found that early anticoagulation treatment effectively suppressed the activities of caspase-3 and caspase-9, upregulated the protein expression of vascular endothelial growth factor (VEGF) and decreased the protein expression of protease-activated receptor 1 (PAR1) in the severe burns model. It was concluded that early anticoagulation treatment affected the severe burns complicated by inhalation injury in a rabbit model through the upregulation of VEGF and downregulation of PAR1 signaling pathways. Thus, early anticoagulation is a potential therapeutic option for severe burns complicated by inhalation injury. PMID:28944866

Total inpatient treatment costs in patients with severe burns: towards a more accurate reimbursement model.

PubMed

Mehra, Tarun; Koljonen, Virve; Seifert, Burkhardt; Volbracht, Jörk; Giovanoli, Pietro; Plock, Jan; Moos, Rudolf Maria

2015-01-01

Reimbursement systems have difficulties depicting the actual cost of burn treatment, leaving care providers with a significant financial burden. Our aim was to establish a simple and accurate reimbursement model compatible with prospective payment systems. A total of 370 966 electronic medical records of patients discharged in 2012 to 2013 from Swiss university hospitals were reviewed. A total of 828 cases of burns including 109 cases of severe burns were retained. Costs, revenues and earnings for severe and nonsevere burns were analysed and a linear regression model predicting total inpatient treatment costs was established. The median total costs per case for severe burns was tenfold higher than for nonsevere burns (179 949 CHF [167 353 EUR] vs 11 312 CHF [10 520 EUR], interquartile ranges 96 782-328 618 CHF vs 4 874-27 783 CHF, p <0.001). The median of earnings per case for nonsevere burns was 588 CHF (547 EUR) (interquartile range -6 720 - 5 354 CHF) whereas severe burns incurred a large financial loss to care providers, with median earnings of -33 178 CHF (30 856 EUR) (interquartile range -95 533 - 23 662 CHF). Differences were highly significant (p <0.001). Our linear regression model predicting total costs per case with length of stay (LOS) as independent variable had an adjusted R2 of 0.67 (p <0.001 for LOS). Severe burns are systematically underfunded within the Swiss reimbursement system. Flat-rate DRG-based refunds poorly reflect the actual treatment costs. In conclusion, we suggest a reimbursement model based on a per diem rate for treatment of severe burns.

Reliability enhancement through optimal burn-in

NASA Astrophysics Data System (ADS)

Kuo, W.

1984-06-01

A numerical reliability and cost model is defined for production line burn-in tests of electronic components. The necessity of burn-in is governed by upper and lower bounds: burn-in is mandatory for operation-critical or nonreparable component; no burn-in is needed when failure effects are insignificant or easily repairable. The model considers electronic systems in terms of a series of components connected by a single black box. The infant mortality rate is described with a Weibull distribution. Performance reaches a steady state after burn-in, and the cost of burn-in is a linear function for each component. A minimum cost is calculated among the costs and total time of burn-in, shop repair, and field repair, with attention given to possible losses in future sales from inadequate burn-in testing.

77 FR 18297 - Air Traffic Noise, Fuel Burn, and Emissions Modeling Using the Aviation Environmental Design Tool...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-27

... Integrated Routing System-- NIRS].'' The FAA developed the AEDT 2a to model aircraft noise, fuel burn, and... operations schedule. These data are used to compute aircraft noise, fuel burn and emissions simultaneously... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Air Traffic Noise, Fuel Burn, and...

AFIRM-Wake Forest/University of Pittsburgh Consortium

DTIC Science & Technology

2012-07-01

therapy for infected burn wounds using Lactobacillu s was applied to a new m ouse model and is capable of rescuing the anim al from burn wound induced... Lactobacillus to reduce scar from burn wound infection. We have tested bacteriotherapy with Lactobacillus in a rabbit model of Pseudomonas-infected burn...probiotic therapy with Lactobacillus is sufficient to attenuate the length and severity of a Pseudo monal infection of the burn wound, and that this

Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

DTIC Science & Technology

2017-10-01

casualty, treatment, organ failure, systemic inflammatory response syndrome , thermal injury, wound model, intervention 3. ACCOMPLISHMENTS:   What...thickness burns have a blister response. Using human eye or H&E studies, we did not observe any blisters in the pig model. However, the OCT...the deeper the partial thickness burn, the bigger the blister, until it gets close to full-thickness burns. The full-thickness burns are dry and

In vitro burn model illustrating heat conduction patterns using compressed thermal papers.

PubMed

Lee, Jun Yong; Jung, Sung-No; Kwon, Ho

2015-01-01

To date, heat conduction from heat sources to tissue has been estimated by complex mathematical modeling. In the present study, we developed an intuitive in vitro skin burn model that illustrates heat conduction patterns inside the skin. This was composed of tightly compressed thermal papers with compression frames. Heat flow through the model left a trace by changing the color of thermal papers. These were digitized and three-dimensionally reconstituted to reproduce the heat conduction patterns in the skin. For standardization, we validated K91HG-CE thermal paper using a printout test and bivariate correlation analysis. We measured the papers' physical properties and calculated the estimated depth of heat conduction using Fourier's equation. Through contact burns of 5, 10, 15, 20, and 30 seconds on porcine skin and our burn model using a heated brass comb, and comparing the burn wound and heat conduction trace, we validated our model. The heat conduction pattern correlation analysis (intraclass correlation coefficient: 0.846, p < 0.001) and the heat conduction depth correlation analysis (intraclass correlation coefficient: 0.93, p < 0.001) showed statistically significant high correlations between the porcine burn wound and our model. Our model showed good correlation with porcine skin burn injury and replicated its heat conduction patterns. © 2014 by the Wound Healing Society.

MESOSCALE MODELING OF DEFLAGRATION-INDUCED DECONSOLIDATION IN POLYMER-BONDED EXPLOSIVES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Springer, H K; Glascoe, E A; Reaugh, J E

Initially undamaged polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and the evolution of deflagration-induced damage during the transition to convective burning is not well understood. The objective of this study is to investigate the role of microstructure and initial pressurization on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX-Viton A served as our model explosive.more » A Prout-Tompkins chemical kinetic model, Vielle's Law pressure-dependent burning, Gruneisen equation-of-state, and simplified strength model were used for the HMX. The propensity for deconsolidation increased with increasing defect size and decreasing initial pressurization, as measured by the increase in burning surface area. These studies are important because they enable the development of continuum-scale damage models and the design of inherently safer explosives.« less

Modeling prescribed burning experiments and assessing the fire impacts on local to regional air quality

NASA Astrophysics Data System (ADS)

Zhou, L.; Baker, K. R.; Napelenok, S. L.; Elleman, R. A.; Urbanski, S. P.

2016-12-01

Biomass burning, including wildfires and prescribed burns, strongly impact the global carbon cycle and are of increasing concern due to the potential impacts on ambient air quality. This modelling study focuses on the evolution of carbonaceous compounds during a prescribed burning experiment and assesses the impacts of burning on local to regional air quality. The Community Multiscale Air Quality (CMAQ) model is used to conduct 4 and 2 km grid resolution simulations of prescribed burning experiments in southeast Washington state and western Idaho state in summer 2013. The ground and airborne measurements from the field experiment are used to evaluate the model performance in capturing surface and aloft impacts from the burning events. Phase partitioning of organic compounds in the plume are studied as it is a crucial step towards understanding the fate of carbonaceous compounds. The sensitivities of ambient concentrations and deposition to emissions are conducted for organic carbon, elemental carbon and ozone to estimate the impacts of fire on air quality.

Fire spread in chaparral -"go or no-go?"

Treesearch

D.R. Weise; Xiangyang Zhou; Lulu Sun; Shankar Mahalingam

2005-01-01

Current fire models are designed to model the spread of a linear fire front in dead, small-diameter fuels. Fires in predominantly living vegetation account for a large proportion of annual burned area nationally. Prescribed burning is used to manage living fuels; however, prescribed burning is currently conducted under conditions that result in marginal burning. We do...

Determining the Uncertainties in Prescribed Burn Emissions Through Comparison of Satellite Estimates to Ground-based Estimates and Air Quality Model Evaluations in Southeastern US

NASA Astrophysics Data System (ADS)

Odman, M. T.; Hu, Y.; Russell, A. G.

2016-12-01

Prescribed burning is practiced throughout the US, and most widely in the Southeast, for the purpose of maintaining and improving the ecosystem, and reducing the wildfire risk. However, prescribed burn emissions contribute significantly to the of trace gas and particulate matter loads in the atmosphere. In places where air quality is already stressed by other anthropogenic emissions, prescribed burns can lead to major health and environmental problems. Air quality modeling efforts are under way to assess the impacts of prescribed burn emissions. Operational forecasts of the impacts are also emerging for use in dynamic management of air quality as well as the burns. Unfortunately, large uncertainties exist in the process of estimating prescribed burn emissions and these uncertainties limit the accuracy of the burn impact predictions. Prescribed burn emissions are estimated by using either ground-based information or satellite observations. When there is sufficient local information about the burn area, the types of fuels, their consumption amounts, and the progression of the fire, ground-based estimates are more accurate. In the absence of such information satellites remain as the only reliable source for emission estimation. To determine the level of uncertainty in prescribed burn emissions, we compared estimates derived from a burn permit database and other ground-based information to the estimates by the Biomass Burning Emissions Product derived from a constellation of NOAA and NASA satellites. Using these emissions estimates we conducted simulations with the Community Multiscale Air Quality (CMAQ) model and predicted trace gas and particulate matter concentrations throughout the Southeast for two consecutive burn seasons (2015 and 2016). In this presentation, we will compare model predicted concentrations to measurements at monitoring stations and evaluate if the differences are commensurate with our emission uncertainty estimates. We will also investigate if spatial and temporal patterns in the differences reveal the sources of the uncertainty in the prescribed burn emission estimates.

Accuracy of real time radiography burning rate measurement

NASA Astrophysics Data System (ADS)

Olaniyi, Bisola

The design of a solid propellant rocket motor requires the determination of a propellant's burning-rate and its dependency upon environmental parameters. The requirement that the burning-rate be physically measured, establishes the need for methods and equipment to obtain such data. A literature review reveals that no measurement has provided the desired burning rate accuracy. In the current study, flash x-ray modeling and digitized film-density data were employed to predict motor-port area to length ratio. The pre-fired port-areas and base burning rate were within 2.5% and 1.2% of their known values, respectively. To verify the accuracy of the method, a continuous x-ray and a solid propellant rocket motor model (Plexiglas cylinder) were used. The solid propellant motor model was translated laterally through a real-time radiography system at different speeds simulating different burning rates. X-ray images were captured and the burning-rate was then determined. The measured burning rate was within 1.65% of the known values.

Evidence of erosive burning in shuttle solid rocket motor

NASA Technical Reports Server (NTRS)

Martin, C. L.

1983-01-01

Known models of Shuttle Solid Rocket Motor (SRM) performance have failed to produce pressure-time traces which accurately matched actual motor performance, especially during the first 5 seconds after ignition and during the last quarter of web burn time. Efforts to compensate for these differences in model reconstruction and actual performance resulted in resorting to the use of a Burning Anomaly Rate Function (BARF). It was suspected that propellant erosive burning was primarily responsible for the variation of model from actual results. The three dimensional Hercules Grain Design and Internal Ballistics Evaluation Program was made operational and slightly modified and an extensive trial and error effort was begun to test the hypothesis of erosive burning as an explanation of the burning anomaly. It was found that introduction of erosive burning (using Green's erosive burning equation) over portions of the aft segment grain and above a threshold gas Mach number did, in fact, give excellent agreement with the actual motor trace.

Risk factors for the development of heterotopic ossification in seriously burned adults: A National Institute on Disability, Independent Living and Rehabilitation Research burn model system database analysis.

PubMed

Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B; Ring, David C; Kowalske, Karen; Gibran, Nicole S; Herndon, David; Schneider, Jeffrey C; Ryan, Colleen M

2015-11-01

Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study, we use a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Data from six high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. When controlling for age and sex in a multivariate model, patients with greater than 30% total body surface area burn had 11.5 times higher odds of developing HO (p < 0.001), and those with arm burns that required skin grafting had 96.4 times higher odds of developing HO (p = 0.04). For each additional time a patient went to the operating room, odds of HO increased by 30% (odds ratio, 1.32; p < 0.001), and each additional ventilator day increased odds by 3.5% (odds ratio, 1.035; p < 0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Risk factors for HO development include greater than 30% total body surface area burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. Prognostic study, level III.

Risk Factors for the Development of Heterotopic Ossification in Seriously Burned Adults: A NIDRR Burn Model System Database Analysis

PubMed Central

Levi, Benjamin; Jayakumar, Prakash; Giladi, Avi; Jupiter, Jesse B.; Ring, David C.; Kowalske, Karen; Gibran, Nicole S.; Herndon, David; Schneider, Jeffrey C.; Ryan, Colleen M.

2015-01-01

Purpose Heterotopic ossification (HO) is a debilitating complication of burn injury; however, incidence and risk factors are poorly understood. In this study we utilize a multicenter database of adults with burn injuries to identify and analyze clinical factors that predict HO formation. Methods Data from 6 high-volume burn centers, in the Burn Injury Model System Database, were analyzed. Univariate logistic regression models were used for model selection. Cluster-adjusted multivariate logistic regression was then used to evaluate the relationship between clinical and demographic data and the development of HO. Results Of 2,979 patients in the database with information on HO that addressed risk factors for development of HO, 98 (3.5%) developed HO. Of these 98 patients, 97 had arm burns, and 96 had arm grafts. Controlling for age and sex in a multivariate model, patients with >30% total body surface area (TBSA) burn had 11.5x higher odds of developing HO (p<0.001), and those with arm burns that required skin grafting had 96.4x higher odds of developing HO (p=0.04). For each additional time a patient went to the operating room, odds of HO increased 30% (OR 1.32, p<0.001), and each additional ventilator day increase odds 3.5% (OR 1.035, p<0.001). Joint contracture, inhalation injury, and bone exposure did not significantly increase odds of HO. Conclusion Risk factors for HO development include >30% TBSA burn, arm burns, arm grafts, ventilator days, and number of trips to the operating room. Future studies can use these results to identify highest-risk patients to guide deployment of prophylactic and experimental treatments. PMID:26496115

Sensitivity of global terrestrial carbon cycle dynamics to variability in satellite-observed burned area

NASA Astrophysics Data System (ADS)

Poulter, Benjamin; Cadule, Patricia; Cheiney, Audrey; Ciais, Philippe; Hodson, Elke; Peylin, Philippe; Plummer, Stephen; Spessa, Allan; Saatchi, Sassan; Yue, Chao; Zimmermann, Niklaus E.

2015-02-01

Fire plays an important role in terrestrial ecosystems by regulating biogeochemistry, biogeography, and energy budgets, yet despite the importance of fire as an integral ecosystem process, significant advances remain to improve its prognostic representation in carbon cycle models. To recommend and to help prioritize model improvements, this study investigates the sensitivity of a coupled global biogeography and biogeochemistry model, LPJ, to observed burned area measured by three independent satellite-derived products, GFED v3.1, L3JRC, and GlobCarbon. Model variables are compared with benchmarks that include pantropical aboveground biomass, global tree cover, and CO2 and CO trace gas concentrations. Depending on prescribed burned area product, global aboveground carbon stocks varied by 300 Pg C, and woody cover ranged from 50 to 73 Mkm2. Tree cover and biomass were both reduced linearly with increasing burned area, i.e., at regional scales, a 10% reduction in tree cover per 1000 km2, and 0.04-to-0.40 Mg C reduction per 1000 km2. In boreal regions, satellite burned area improved simulated tree cover and biomass distributions, but in savanna regions, model-data correlations decreased. Global net biome production was relatively insensitive to burned area, and the long-term land carbon sink was robust, 2.5 Pg C yr-1, suggesting that feedbacks from ecosystem respiration compensated for reductions in fuel consumption via fire. CO2 transport provided further evidence that heterotrophic respiration compensated any emission reductions in the absence of fire, with minor differences in modeled CO2 fluxes among burned area products. CO was a more sensitive indicator for evaluating fire emissions, with MODIS-GFED burned area producing CO concentrations largely in agreement with independent observations in high latitudes. This study illustrates how ensembles of burned area data sets can be used to diagnose model structures and parameters for further improvement and also highlights the importance in considering uncertainties and variability in observed burned area data products for model applications.

The Synthesis of 44Ti and 56Ni in Massive Stars

NASA Astrophysics Data System (ADS)

Chieffi, Alessandro; Limongi, Marco

2017-02-01

We discuss the influence of rotation on the combined synthesis of {}44{Ti} and {}56{Ni} in massive stars. While {}56{Ni} is significantly produced by both complete and incomplete explosive Si burning, {}44{Ti} is mainly produced by complete explosive Si burning, with a minor contribution (in standard non-rotating models) from incomplete explosive Si burning and O burning (both explosive and hydrostatic). We find that, in most cases, the thickness of the region exposed to incomplete explosive Si burning increases in rotating models (initial velocity, v ini = 300 km s-1) and since {}56{Ni} is significantly produced in this zone, the fraction of mass coming from the complete explosive Si burning zone necessary to get the required amount of {}56{Ni} reduces. Therefore the amount of {}44{Ti} ejected for a given fixed amount of {}56{Ni} decreases in rotating models. However, some rotating models at [Fe/H] = -1 develop a very extended O convective shell in which a consistent amount of {}44{Ti} is formed, preserved, and ejected in the interstellar medium. Hence a better modeling of the thermal instabilities (convection) in the advanced burning phases together with a critical analysis of the cross sections of the nuclear reactions operating in O burning are relevant for the understanding of the synthesis of {}44{Ti}.

The importance of illumination in a non-contact photoplethysmography imaging system for burn wound assessment

NASA Astrophysics Data System (ADS)

Mo, Weirong; Mohan, Rachit; Li, Weizhi; Zhang, Xu; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffery E.

2015-02-01

We present a non-contact, reflective photoplethysmogram (PPG) imaging method and a prototype system for identifying the presence of dermal burn wounds during a burn debridement surgery. This system aims to provide assistance to clinicians and surgeons in the process of dermal wound management and wound triage decisions. We examined the system variables of illumination uniformity and intensity and present our findings. An LED array, a tungsten light source, and eventually high-power LED emitters were studied as illumination methods for our PPG imaging device. These three different illumination sources were tested in a controlled tissue phantom model and an animal burn model. We found that the low heat and even illumination pattern using high power LED emitters provided a substantial improvement to the collected PPG signal in our animal burn model. These improvements allow the PPG signal from different pixels to be comparable in both time-domain and frequency-domain, simplify the illumination subsystem complexity, and remove the necessity of using high dynamic range cameras. Through the burn model output comparison, such as the blood volume in animal burn data and controlled tissue phantom model, our optical improvements have led to more clinically applicable images to aid in burn assessment.

Skin bioengineering: preclinical and clinical applications.

PubMed

Martínez-Santamaría, L; Guerrero-Aspizua, S; Del Río, M

2012-01-01

Regenerative Medicine is an emerging field that combines basic research and clinical observations in order to identify the elements required to replace damaged tissues and organs in vivo and to stimulate the body's intrinsic regenerative capacity. Great benefits are expected in this field as researchers take advantage of the potential regenerative properties of both embryonic and adult stem cells, and more recently, of induced pluripotent stem cells. Bioengineered skin emerged mainly in response to a critical need for early permanent coverage of extensive burns. Later this technology was also applied to the treatment of chronic ulcers. Our group has established a humanized mouse model of skin grafting that involves the use of bioengineered human skin in immunodeficient mice. This model is suitable for the study of physiologic and pathologic cutaneous processes and the evaluation of treatment strategies for skin diseases, including protocols for gene and cell therapy and tissue engineering. Copyright © 2011 Elsevier España, S.L. and AEDV. All rights reserved.

A model of ponderosa pine growth response to prescribed burning

Treesearch

Elaine Kennedy Sutherland; W. Wallace Covington; Steve Andariese

1991-01-01

Our objective was to model the radial growth response of individual ponderosa pines to prescribed burning in northern Arizona. We sampled 188 trees from two study areas, which were burned in 1976. Within each study area, control and burned trees were of similar age, vigor, height, and competition index. At Chimney Spring, trees were older, less vigorous, and taller and...

Biomass Burning

Atmospheric Science Data Center

2015-07-27

Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

A mobile app for measuring the surface area of a burn in three dimensions: comparison to the Lund and Browder assessment.

PubMed

Goldberg, Harry; Klaff, Justin; Spjut, Aaron; Milner, Stephen

2014-01-01

The aim of this study was to compare the ease and accuracy of measuring the surface area of a severe burn through the use of a mobile software application (BurnMed) to the traditional method of assessment, the Lund and Browder chart. BurnMed calculates the surface area of a burn by enabling the user to first manipulate a three-dimensional model on a mobile device and then by touching the model at the locations representing the patient's injury. The surface area of the burn is calculated in real time. Using a cohort of 18 first-year medical students with no experience in burn care, the surface area of a simulated burn on a mannequin was made using BurnMed and compared to estimates derived from the Lund and Browder chart. At the completion of this study, students were asked to complete a questionnaire designed to assess the ease of use of BurnMed. Users were able to easily and accurately measure the surface area of a simulated burn using the BurnMed application. In addition, there was less variability in surface area measurements with the application compared to the results obtained using the Lund and Browder chart. Users also reported that BurnMed was easier to use than the Lund and Browder chart. A software application, BurnMed, has been developed for a mobile device that easily and accurately determines the surface area of a burn. This system uses a three-dimensional model that can be rotated, enlarged, and transposed by the health care provider to easily determine the extent of a burn. Results show that the variability of measurements using BurnMed is lower than the measurements obtained using the Lund and Browder chart. BurnMed is available at no charge in the Apple™ Store.

Integrating satellite imagery with simulation modeling to improve burn severity mapping

Treesearch

Eva C. Karau; Pamela G. Sikkink; Robert E. Keane; Gregory K. Dillon

2014-01-01

Both satellite imagery and spatial fire effects models are valuable tools for generating burn severity maps that are useful to fire scientists and resource managers. The purpose of this study was to test a new mapping approach that integrates imagery and modeling to create more accurate burn severity maps. We developed and assessed a statistical model that combines the...

The effect of a honey based gel and silver sulphadiazine on bacterial infections of in vitro burn wounds.

PubMed

Boekema, B K H L; Pool, L; Ulrich, M M W

2013-06-01

Bacterial contamination remains a constant threat in burn wound care. Topical treatments to combat contaminations have good bactericidal effects but can have detrimental effects for the healing process. Treatments with for example silver can increase healing times. Honey based products can be a good alternative as it is antibacterial and patient-friendly. We evaluated the bactericidal and cytotoxic effects of a honey based gel and silver sulphadiazine in a human burn wound model with Pseudomonas aeruginosa. After adding 10(5)colony forming units of P. aeruginosa, topical treatments were applied on the burn wound models. After 2, 12, 24, 28 and 70 h, bacteria were dislodged and counted by plating dilutions. Cytotoxic effects were evaluated histologically in samples of burn wound models treated topically for 3 weeks, without bacteria. L-Mesitran Soft significantly reduced the bacterial load (5-log reduction) up to 24h but did not completely eliminate bacteria from the burn wounds. After Flammazine(®) treatment, only a few colony forming units were observed at all time points. In contrast, re-epithelialization was significantly reduced after application of Flammazine(®) compared to L-Mesitran Soft or control. This in vitro model of burn wound infection can be used to evaluate topical treatments. L-Mesitran Soft is a good alternative for treating burn wounds but the slightly lower bactericidal activity in the burn wound model warrants a higher frequency of application. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Recent Biomass Burning in the Tropics and Related Changes in Tropospheric Ozone

NASA Technical Reports Server (NTRS)

Ziemke; Chandra, J. R. S.; Duncan, B. N.; Schoeberl, M. R.; Torres, O.; Damon, M. R.; Bhartia, P. K.

2009-01-01

Biomass burning is an important source of chemical precursors of tropospheric ozone. In the tropics, biomass burning produces ozone enhancements over broad regions of Indonesia, Africa, and South America including Brazil. Fires are intentionally set in these regions during the dry season each year to clear cropland and to clear land for human/industrial expansion. In Indonesia enhanced burning occurs during dry El Nino conditions such as in 1997 and 2006. These burning activities cause enhancement in atmospheric particulates and trace gases which are harmful to human health. Measurements from the Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) from October 2004-November 2008 are used to evaluate the effects of biomass burning on tropical tropospheric ozone. These measurements show sizeable decreases approx.15-20% in ozone in Brazil during 2008 compared to 2007 which we attribute to the reduction in biomass burning. Three broad biomass burning regions in the tropics (South America including Brazil, western Africa, and Indonesia) were analyzed in the context of OMI/MLS measurements and the Global Modeling Initiative (GMI) chemical transport model developed at Goddard Space Flight Center. The results indicate that the impact of biomass burning on ozone is significant within and near the burning regions with increases of approx.10-25% in tropospheric column ozone relative to average background concentrations. The model suggests that about half of the increases in ozone from these burning events come from altitudes below 3 km. Globally the model indicates increases of approx.4-5% in ozone, approx.7-9% in NO, (NO+NO2), and approx.30-40% in CO.

Modeling Emissions and Vertical Plume Transport of Crop Residue Burning Experiments in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Zhou, L.; Baker, K. R.; Napelenok, S. L.; Pouliot, G.; Elleman, R. A.; ONeill, S. M.; Urbanski, S. P.; Wong, D. C.

2017-12-01

Crop residue burning has long been a common practice in agriculture with the smoke emissions from the burning linked to negative health impacts. A field study in eastern Washington and northern Idaho in August 2013 consisted of multiple burns of well characterized fuels with nearby surface and aerial measurements including trace species concentrations, plume rise height and boundary layer structure. The chemical transport model CMAQ (Community Multiscale Air Quality Model) was used to assess the fire emissions and subsequent vertical plume transport. The study first compared assumptions made by the 2014 National Emission Inventory approach for crop residue burning with the fuel and emissions information obtained from the field study and then investigated the sensitivity of modeled carbon monoxide (CO) and PM2.5 concentrations to these different emission estimates and plume rise treatment with CMAQ. The study suggests that improvements to the current parameterizations are needed in order for CMAQ to reliably reproduce smoke plumes from burning. In addition, there is enough variability in the smoke emissions, stemming from variable field-specific information such as field size, that attempts to model crop residue burning should use field-specific information whenever possible.

Modeling crop residue burning experiments to evaluate smoke emissions and plume transport.

PubMed

Zhou, Luxi; Baker, Kirk R; Napelenok, Sergey L; Pouliot, George; Elleman, Robert; O'Neill, Susan M; Urbanski, Shawn P; Wong, David C

2018-06-15

Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment in the Pacific Northwest focused on cropland residue burning was used to evaluate model performance in capturing surface and aloft impacts from the burning events. The Community Multiscale Air Quality (CMAQ) model was used to simulate multiple crop residue burns with 2 km grid spacing using field-specific information and also more general assumptions traditionally used to support National Emission Inventory based assessments. Field study specific information, which includes area burned, fuel consumption, and combustion completeness, resulted in increased biomass consumption by 123 tons (60% increase) on average compared to consumption estimated with default methods in the National Emission Inventory (NEI) process. Buoyancy heat flux, a key parameter for model predicted fire plume rise, estimated from fuel loading obtained from field measurements can be 30% to 200% more than when estimated using default field information. The increased buoyancy heat flux resulted in higher plume rise by 30% to 80%. This evaluation indicates that the regulatory air quality modeling system can replicate intensity and transport (horizontal and vertical) features for crop residue burning in this region when region-specific information is used to inform emissions and plume rise calculations. Further, previous vertical emissions allocation treatment of putting all cropland residue burning in the surface layer does not compare well with measured plume structure and these types of burns should be modeled more similarly to prescribed fires such that plume rise is based on an estimate of buoyancy. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessment of biomass burning emissions and their impacts on urban and regional PM2.5: a Georgia case study.

PubMed

Tian, Di; Hu, Yongtao; Wang, Yuhang; Boylan, James W; Zheng, Mei; Russell, Armistead G

2009-01-15

Biomass burning is a major and growing contributor to particulate matter with an aerodynamic diameter less than 2.5 microm (PM2.5). Such impacts (especially individual impacts from each burning source) are quantified using the Community Multiscale Air Quality (CMAQ) Model, a chemical transport model (CTM). Given the sensitivity of CTM results to uncertain emission inputs, simulations were conducted using three biomass burning inventories. Shortcomings in the burning emissions were also evaluated by comparing simulations with observations and results from a receptor model. Model performance improved significantly with the updated emissions and speciation profiles based on recent measurements for biomass burning: mean fractional bias is reduced from 22% to 4% for elemental carbon and from 18% to 12% for organic matter; mean fractional error is reduced from 59% to 50% for elemental carbon and from 55% to 49% for organic matter. Quantified impacts of biomass burning on PM2.5 during January, March, May, and July 2002 are 3.0, 5.1, 0.8, and 0.3 microg m(-3) domainwide on average, with more than 80% of such impacts being from primary emissions. Impacts of prescribed burning dominate biomass burning impacts, contributing about 55% and 80% of PM2.5 in January and March, respectively, followed by land clearing and agriculture field burning. Significant impacts of wildfires in May and residential wood combustion in fireplaces and woodstoves in January are also found.

Towards more efficient burn care: Identifying factors associated with good quality of life post-burn.

PubMed

Finlay, V; Phillips, M; Allison, G T; Wood, F M; Ching, D; Wicaksono, D; Plowman, S; Hendrie, D; Edgar, D W

2015-11-01

As minor burn patients constitute the vast majority of a developed nation case-mix, streamlining care for this group can promote efficiency from a service-wide perspective. This study tested the hypothesis that a predictive nomogram model that estimates likelihood of good long-term quality of life (QoL) post-burn is a valid way to optimise patient selection and risk management when applying a streamlined model of care. A sample of 224 burn patients managed by the Burn Service of Western Australia who provided both short and long-term outcomes was used to estimate the probability of achieving a good QoL defined as 150 out of a possible 160 points on the Burn Specific Health Scale-Brief (BSHS-B) at least six months from injury. A multivariate logistic regression analysis produced a predictive model provisioned as a nomogram for clinical application. A second, independent cohort of consecutive patients (n=106) was used to validate the predictive merit of the nomogram. Male gender (p=0.02), conservative management (p=0.03), upper limb burn (p=0.04) and high BSHS-B score within one month of burn (p<0.001) were significant predictors of good outcome at six months and beyond. A Receiver Operating Curve (ROC) analysis demonstrated excellent (90%) accuracy overall. At 80% probability of good outcome, the false positive risk was 14%. The nomogram was validated by running a second ROC analysis of the model in an independent cohort. The analysis confirmed high (86%) overall accuracy of the model, the risk of false positive was reduced to 10% at a lower (70%) probability. This affirms the stability of the nomogram model in different patient groups over time. An investigation of the effect of missing data on sample selection determined that a greater proportion of younger patients with smaller TBSA burns were excluded due to loss to follow up. For clinicians managing comparable burn populations, the BSWA burns nomogram is an effective tool to assist the selection of patients to a streamlined care pathway with the aim of improving efficiency of service delivery. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Photoacoustic diagnosis of burns in rats: two-dimensional photo-acoustic imaging of burned tissue

NASA Astrophysics Data System (ADS)

Yamazaki, Mutsuo; Sato, Shunichi; Saito, Daizo; Okada, Yoshiaki; Kurita, Akira; Kikuchi, Makoto; Ashida, Hiroshi; Obara, Minoru

2003-06-01

We previously reported that for rat burn models, deep dermal burns and deep burns can be well differentiated by measuring the propagation time of the photoacoustic signals originated from the blood in the healthy skin tissue under the damaged tissue layer. However, the diagnosis was based on point measurement in the wound, and therefore site-dependent information on the injuries was not obtained; such information is very important for diagnosis of extended burns. In the present study, we scanned a photoacoustic detector on the wound and constructed two-dimensional (2-D) images of the blood-originated photoacoustic signals for superficial dermal burns (SDB), deep dermal burns (DDB), deep burns (DB), and healthy skins (control) in rats. For each burn model, site-dependent variation of the signal was observed; the variation probably reflects the distribution of blood vessels in the skin tissue. In spite of the variation, clear differentiation was obtained between SDB, DDB, and DB from the 2D images. The images were constructed as a function of post burn time. Temporal signal variation will be also presented.

Quantifying the influence of boreal biomass burning emissions on tropospheric oxidant chemistry over the North Atlantic using BORTAS measurements

NASA Astrophysics Data System (ADS)

Parrington, Mark; Palmer, Paul I.; Rickard, Andrew; Young, Jennifer; Lewis, Ally; Lee, James; Henze, Daven; Tarasick, David; Hyer, Edward; Yantosca, Robert; Bowman, Kevin; Worden, John; Griffin, Debora; Franklin, Jonathan; Helmig, Detlev

2013-04-01

We use the GEOS-Chem chemistry transport model to quantify the impact of boreal biomass burning on tropospheric oxidant chemistry over the North Atlantic region during summer of 2011. The GEOS-Chem model is used at a spatial resolution of 1/2 degree latitude by 2/3 degree longitude for a domain covering eastern North America, the North Atlantic Ocean and western Europe. We initialise the model with biomass burning emissions from the Fire Locating and Monitoring of Burning Emissions (FLAMBE) inventory and use a modified chemical mechanism providing a detailed description of ozone photochemistry in boreal biomass burning outflow derived from the Master Chemical Mechanism (MCM). We evaluate the 3-D model distribution of ozone and tracers associated with biomass burning against measurements made by the UK FAAM BAe-146 research aircraft, ozonesondes, ground-based and satellite instruments as part of the BORTAS experiment between 12 July and 3 August 2011. We also use the GEOS-Chem model adjoint to fit the model to BORTAS measurements to analyse the sensitivity of the model chemical mechanism and ozone distribution to wildfire emissions in central Canada.

A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

NASA Technical Reports Server (NTRS)

Kibbey, Timothy P.

2014-01-01

A derivation of turbulent flow parameters, combined with data from erosive burning test motors and blowing wall tests results in erosive burning model candidates useful in one-dimensional internal ballistics analysis capable of scaling across wide ranges of motor size. The real-time burn rate data comes from three test campaigns of subscale segmented solid rocket motors tested at two facilities. The flow theory admits the important effect of the blowing wall on the turbulent friction coefficient by using blowing wall data to determine the blowing wall friction coefficient. The erosive burning behavior of full-scale motors is now predicted more closely than with other recent models.

Vegetation management with fire modifies peatland soil thermal regime.

PubMed

Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

2015-05-01

Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from <2 to 15 + years post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (<2-4 years) showed higher mean, maximum and range of soil temperatures, and lower minima. Statistical models (generalised least square regression) were developed to predict daily mean and maximum soil temperature in plots burned 15 + years prior to the study. These models were then applied to predict temperatures of plots burned 2, 4 and 7 years previously, with significant deviations from predicted temperatures illustrating the magnitude of burn management effects. Temperatures measured in soil plots burned <2 years previously showed significant statistical disturbances from model predictions, reaching +6.2 °C for daily mean temperatures and +19.6 °C for daily maxima. Soil temperatures in plots burnt 7 years previously were most similar to plots burned 15 + years ago indicating the potential for soil temperatures to recover as vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

P311 Accelerates Skin Wound Reepithelialization by Promoting Epidermal Stem Cell Migration Through RhoA and Rac1 Activation.

PubMed

Yao, Zhihui; Li, Haisheng; He, Weifeng; Yang, Sisi; Zhang, Xiaorong; Zhan, Rixing; Xu, Rui; Tan, Jianglin; Zhou, Junyi; Wu, Jun; Luo, Gaoxing

2017-03-15

P311 is a newly discovered functional gene, and it has been proved to play a key role in blood pressure homeostasis, glioblastoma invasion, renal fibrosis, hypertrophic scar formation, and others. In this study, for the first time, we found that P311 could enhance reepithelialization during wound healing via promoting epidermal stem cell (EpSC) migration through Rho GTPases. P311 expression was highly increased in neo-epidermal cells during human and mouse skin wound healing, and P311was co-localized with 5-bromo-2'-deoxyuridine positive label-retaining cells in a mouse superficial second-degree burn wound model. Furthermore, transfection of human EpSCs with adenovirus encoding P311 significantly accelerated the cell migration in vitro. Moreover, highly expressed P311 could enhance the activities of the Rho GTPases (RhoA, Rac1, and Cdc42) in cultured human EpSCs. P311-knockout mouse EpSCs showed dramatically decreased cell migration and activities of Rho GTPases (RhoA, Rac1, and Cdc42). Besides, both the RhoA-specific inhibitor and the Rac1 inhibitor, not the Cdc42 inhibitor, could significantly suppress P311-induced human EpSC migration. In vivo, the reepithelialization was markedly impaired during wound healing after P311 was knocked out. Together, our results suggested that P311 could accelerate skin wound reepithelialization by promoting the migration of EpSCs through RhoA and Rac1 activation. P311 could serve as a novel target for regulation of EpSC migration during cutaneous wound healing.

Accuracy of Currently Used Paper Burn Diagram vs a Three-Dimensional Computerized Model.

PubMed

Benjamin, Nicole C; Lee, Jong O; Norbury, William B; Branski, Ludwik K; Wurzer, Paul; Jimenez, Carlos J; Benjamin, Debra A; Herndon, David N

Burn units have historically used paper diagrams to estimate percent burn; however, unintentional errors can occur. The use of a computer program that incorporates wound mapping from photographs onto a three-dimensional (3D) human diagram could decrease subjectivity in preparing burn diagrams and subsequent calculations of TBSA burned. Analyses were done on 19 burned patients who had an estimated TBSA burned of ≥20%. The patients were admitted to Shriners Hospitals for Children or the University of Texas Medical Branch in Galveston, Texas, from July 2012 to September 2013 for treatment. Digital photographs were collected before the patient's first surgery. Using BurnCase 3D (RISC Software GmbH, Hagenberg, Austria), a burn mapping software, the user traced partial- and full-thickness burns from photographs. The program then superimposed tracings onto a 3D model and calculated percent burned. The results were compared with the Lund and Browder diagrams completed after the first operation. A two-tailed t-test was used to calculate statistical differences. For partial-thickness burns, burn sizes calculated using Lund and Browder diagrams were significantly larger than those calculated using BurnCase 3D (15% difference, P < .01). The opposite was found for full-thickness burns, with burn sizes being smaller when calculated using Lund and Browder diagrams (11% difference, P < .05). In conclusion, substantial differences exist in percent burn estimations derived from BurnCase 3D and paper diagrams. In our studied cohort, paper diagrams were associated with overestimation of partial-thickness burn size and underestimation of full-thickness burn size. Additional studies comparing BurnCase 3D with other commonly used methods are warranted.

Using multilevel spatial models to understand salamander site occupancy patterns after wildfire

USGS Publications Warehouse

Chelgren, Nathan; Adams, Michael J.; Bailey, Larissa L.; Bury, R. Bruce

2011-01-01

Studies of the distribution of elusive forest wildlife have suffered from the confounding of true presence with the uncertainty of detection. Occupancy modeling, which incorporates probabilities of species detection conditional on presence, is an emerging approach for reducing observation bias. However, the current likelihood modeling framework is restrictive for handling unexplained sources of variation in the response that may occur when there are dependence structures such as smaller sampling units that are nested within larger sampling units. We used multilevel Bayesian occupancy modeling to handle dependence structures and to partition sources of variation in occupancy of sites by terrestrial salamanders (family Plethodontidae) within and surrounding an earlier wildfire in western Oregon, USA. Comparison of model fit favored a spatial N-mixture model that accounted for variation in salamander abundance over models that were based on binary detection/non-detection data. Though catch per unit effort was higher in burned areas than unburned, there was strong support that this pattern was due to a higher probability of capture for individuals in burned plots. Within the burn, the odds of capturing an individual given it was present were 2.06 times the odds outside the burn, reflecting reduced complexity of ground cover in the burn. There was weak support that true occupancy was lower within the burned area. While the odds of occupancy in the burn were 0.49 times the odds outside the burn among the five species, the magnitude of variation attributed to the burn was small in comparison to variation attributed to other landscape variables and to unexplained, spatially autocorrelated random variation. While ordinary occupancy models may separate the biological pattern of interest from variation in detection probability when all sources of variation are known, the addition of random effects structures for unexplained sources of variation in occupancy and detection probability may often more appropriately represent levels of uncertainty. ?? 2011 by the Ecological Society of America.

40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

Code of Federal Regulations, 2011 CFR

2011-07-01

... Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of..., Table 8 Table 8 to Subpart DDDD of Part 60—Model Rule—Emission Limitations That Apply to Waste-Burning... to Waste-Burning Kilns After May 20, 2011 For the air pollutant You must meet this emissionlimitation...

The helminth community of the wood mouse Apodemus sylvaticus in a Mediterranean ecosystem in regeneration ten years after a wildfire.

PubMed

Fuentes, M V; Sainz-Elipe, S; Sáez-Durán, S; Galán-Puchades, M T

2010-03-01

This study was carried out 10 years after a wildfire in the Spanish Serra Calderona Natural Park, following a previous analysis comprising the first 5 years after the fire. Its primary aim was to elucidate the impact of this perturbation on the population biology of the wood mouse Apodemus sylvaticus, and the repercussions on its helminth community in this regenerating Mediterranean ecosystem. Second, confirmation of the ability of the parasites to tolerate environmental stressors and the effects on their transmission strategies was sought. Five hundred and sixty-four individuals of A. sylvaticus were studied in a 9-year period, from the second to the tenth post-fire year: 408 mice from the burned area and 156 from the control--non-burned--area. The helminth community for both areas and the effect of intrinsic (host age and sex) and extrinsic (site, period and year of capture) factors on helminth prevalence, abundance and diversity, and species richness were analysed. Our findings show that, after an environmental disaster, the behaviour of helminth species might be related to their pre-catastrophe presence, their biological cycles, the host's immunological condition, the change of host dynamics, the direct effects of the perturbation, and the processes related to the re-establishment of the ecological balance of a devastated ecosystem.

Photoacoustic signal measurement for burned skins in the spectral range of 500-650 nm: experiment with rat burn models

NASA Astrophysics Data System (ADS)

Yamazaki, Mutsuo; Sato, Shunichi; Saito, Daizo; Fujita, Masanori; Okada, Yoshiaki; Kikuchi, Makoto; Ashida, Hiroshi; Obara, Minoru

2002-06-01

This paper reports the burn diagnosis that is based on the measurement of photoacoustic waves from skin, where the acoustic waves originate from the absorption of light by blood. For this purpose, a transducer composed of a ring-shaped piezoelectric film and a quartz fiber was made. An optical parametric oscillator (500 - 650 nm) was used as a light source and its output pulses were coupled to the quartz fiber. To investigate the optimum light wavelength, we conducted experiments using rat burn models. We demonstrated that the superficial dermal burn (SDB), deep dermal burn (DDB), deep burn (DB), and control (healthy skin) could be clearly differentiated based on the photoacoustic signals induced by the light of 532 - 580nm.

Climate vs. carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

NASA Astrophysics Data System (ADS)

Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

2014-02-01

Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness; CO2 availability, in turn, constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence CO2 availability, the links between atmospheric CO2 and biomass burning are not well known. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to CO2 increase, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided Last Glacial Maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase 2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes in biomass burning were corrected for the model's observed biases in contemporary biome-average values. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux was 70 to 80% lower at the LGM than in PI time. LGM climate with pre-industrial CO2 (280 ppm) however yielded unrealistic results, with global and Northern Hemisphere biomass burning fluxes greater than in the pre-industrial climate. Using the PI CO2 concentration increased the modelled LGM biomass burning fluxes for all climate models and latitudinal bands to between four and ten times their values under LGM CO2 concentration. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on productivity and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

The Protective Effects of Epigallocatechin Gallate Against Distant Organ Damage After Severe Skin Burns--Experimental Study Using a Rat Model of Thermal Trauma.

PubMed

Hosnuter, Mubin; Melikoglu, Cenk; Aslan, Cem; Saglam, Gulcan; Sutcu, Recep

2015-01-01

Epigallocatechin gallate (EGCG), a green tea polyphenol, has potent antioxidant properties. The purpose of the present study was to examine the possible preventative effects of EGCG against internal organ injury due to large-surface skin burns in a rat model. The study design involved three groups of rats: a sham group and two groups with 25-30% full-thickness burns: (a) the sham group without burns or treatment (n=18); (b) the control burn group (burns+sterile saline, n=18); and (c) the burn treatment group (burns+treatment with EGCG, n=18). EGCG was administered intraperitoneally immediately after the thermal injury, and daily in 100 μmol/kg doses. Kidney and lung tissue samples were taken to determine the levels of malondialdehyde (MDA), superoxide dismutase (SOD), tumor necrosis factor-α (TNF-α), and glutathione peroxidase (GPX) after the first, third and seventh post-burn days. In the EGCG-treated burn group, SOD and GPX activity were significantly higher than in the burn control group. Additionally, MDA and TNF-α levels were significantly lower in the EGCG-treated burn group. Based on this study, it might be anticipated that EGCG treatment may be beneficial in burn injury cases.

What determines area burned in large landscapes? Insights from a decade of comparative landscape-fire modelling

Treesearch

Geoffrey J. Cary; Robert E. Keane; Mike D. Flannigan; Ian D. Davies; Russ A. Parsons

2015-01-01

Understanding what determines area burned in large landscapes is critical for informing wildland fire management in fire-prone environments and for representing fire activity in Dynamic Global Vegetation Models. For the past ten years, a group of landscape-fire modellers have been exploring the relative influence of key determinants of area burned in temperate and...

Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

EPA Science Inventory

Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also ...

A Modeling Approach for Burn Scar Assessment Using Natural Features and Elastic Property

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsap, L V; Zhang, Y; Goldgof, D B

2004-04-02

A modeling approach is presented for quantitative burn scar assessment. Emphases are given to: (1) constructing a finite element model from natural image features with an adaptive mesh, and (2) quantifying the Young's modulus of scars using the finite element model and the regularization method. A set of natural point features is extracted from the images of burn patients. A Delaunay triangle mesh is then generated that adapts to the point features. A 3D finite element model is built on top of the mesh with the aid of range images providing the depth information. The Young's modulus of scars ismore » quantified with a simplified regularization functional, assuming that the knowledge of scar's geometry is available. The consistency between the Relative Elasticity Index and the physician's rating based on the Vancouver Scale (a relative scale used to rate burn scars) indicates that the proposed modeling approach has high potentials for image-based quantitative burn scar assessment.« less

Growth rate predicts mortality of Abies concolor in both burned and unburned stands

USGS Publications Warehouse

van Mantgem, Phillip J.; Stephenson, Nathan L.; Mutch, Linda S.; Johnson, Veronica G.; Esperanza, Annie M.; Parsons, David J.

2003-01-01

Tree mortality is often the result of both long-term and short-term stress. Growth rate, an indicator of long-term stress, is often used to estimate probability of death in unburned stands. In contrast, probability of death in burned stands is modeled as a function of short-term disturbance severity. We sought to narrow this conceptual gap by determining (i) whether growth rate, in addition to crown scorch, is a predictor of mortality in burned stands and (ii) whether a single, simple model could predict tree death in both burned and unburned stands. Observations of 2622 unburned and 688 burned Abies concolor (Gord. & Glend.) Lindl. (white fir) in the Sierra Nevada of California, U.S.A., indicated that growth rate was a significant predictor of mortality in the unburned stands, while both crown scorch and radial growth were significant predictors of mortality in the burned stands. Applying the burned stand model to unburned stands resulted in an overestimation of the unburned stand mortality rate. While failing to create a general model of tree death for A. concolor, our findings underscore the idea that similar processes may affect mortality in disturbed and undisturbed stands.

Empirical models to predict the volumes of debris flows generated by recently burned basins in the western U.S.

USGS Publications Warehouse

Gartner, J.E.; Cannon, S.H.; Santi, P.M.; deWolfe, V.G.

2008-01-01

Recently burned basins frequently produce debris flows in response to moderate-to-severe rainfall. Post-fire hazard assessments of debris flows are most useful when they predict the volume of material that may flow out of a burned basin. This study develops a set of empirically-based models that predict potential volumes of wildfire-related debris flows in different regions and geologic settings. The models were developed using data from 53 recently burned basins in Colorado, Utah and California. The volumes of debris flows in these basins were determined by either measuring the volume of material eroded from the channels, or by estimating the amount of material removed from debris retention basins. For each basin, independent variables thought to affect the volume of the debris flow were determined. These variables include measures of basin morphology, basin areas burned at different severities, soil material properties, rock type, and rainfall amounts and intensities for storms triggering debris flows. Using these data, multiple regression analyses were used to create separate predictive models for volumes of debris flows generated by burned basins in six separate regions or settings, including the western U.S., southern California, the Rocky Mountain region, and basins underlain by sedimentary, metamorphic and granitic rocks. An evaluation of these models indicated that the best model (the Western U.S. model) explains 83% of the variability in the volumes of the debris flows, and includes variables that describe the basin area with slopes greater than or equal to 30%, the basin area burned at moderate and high severity, and total storm rainfall. This model was independently validated by comparing volumes of debris flows reported in the literature, to volumes estimated using the model. Eighty-seven percent of the reported volumes were within two residual standard errors of the volumes predicted using the model. This model is an improvement over previous models in that it includes a measure of burn severity and an estimate of modeling errors. The application of this model, in conjunction with models for the probability of debris flows, will enable more complete and rapid assessments of debris flow hazards following wildfire.

Cooling of burns: Mechanisms and models.

PubMed

Wright, E H; Harris, A L; Furniss, D

2015-08-01

The role of cooling in the acute management of burns is widely accepted in clinical practice, and is a cornerstone of basic first aid in burns. This has been underlined in a number of animal models. The mechanism by which it delivers its benefit is poorly understood, but there is a reduction in burns progression over the first 48 h, reduced healing time, and some subjective improvements in scarring when cooling is administered after burning. Intradermal temperature normalises within a matter of seconds to a few minutes, yet the benefits of even delayed cooling persist, implying it is not simply the removal of thermal energy from the damaged tissues. Animal models have used oedema formation, preservation of dermal perfusion, healing time and hair retention as indicators of burns severity, and have shown cooling to improve these indices, but pharmacological or immunological blockade of humoural and cellular mediators of inflammation did not reproduce the benefit of cooling. More recently, some studies of tissue from human and animal burns have shown consistent, reproducible, temporal changes in gene expression in burned tissues. Here, we review the experimental evidence of the role and mechanism of cooling in burns management, and suggest future research directions that may eventually lead to improved treatment outcomes. Copyright © 2015. Published by Elsevier Ltd.

Comparison of mortality prediction models in burns ICU patients in Pinderfields Hospital over 3 years.

PubMed

Douglas, Helen E; Ratcliffe, Andrew; Sandhu, Rajdeep; Anwar, Umair

2015-02-01

Many different burns mortality prediction models exist; however most agree that important factors that can be weighted include the age of the patient, the total percentage of body surface area burned and the presence or absence of smoke inhalation. A retrospective review of all burns primarily admitted to Pinderfields Burns ICU under joint care of burns surgeons and intensivists for the past 3 years was completed. Predicted mortality was calculated using the revised Baux score (2010), the Belgian Outcome in Burn Injury score (2009) and the Boston group score by Ryan et al. (1998). Additionally 28 of the 48 patients had APACHE II scores recorded on admission and the predicted and actual mortality of this group were compared. The Belgian score had the highest sensitivity and negative predictive value (72%/85%); followed by the Boston score (66%/78%) and then the revised Baux score (53%/70%). APACHE II scores had higher sensitivity (81%) and NPV (92%) than any of the burns scores. In our group of burns ICU patients the Belgian model was the most sensitive and specific predictor of mortality. In our subgroup of patients with APACHE II data, this score more accurately predicted survival and mortality. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Study of Burn Scar Extraction Automatically Based on Level Set Method using Remote Sensing Data

PubMed Central

Liu, Yang; Dai, Qin; Liu, JianBo; Liu, ShiBin; Yang, Jin

2014-01-01

Burn scar extraction using remote sensing data is an efficient way to precisely evaluate burn area and measure vegetation recovery. Traditional burn scar extraction methodologies have no well effect on burn scar image with blurred and irregular edges. To address these issues, this paper proposes an automatic method to extract burn scar based on Level Set Method (LSM). This method utilizes the advantages of the different features in remote sensing images, as well as considers the practical needs of extracting the burn scar rapidly and automatically. This approach integrates Change Vector Analysis (CVA), Normalized Difference Vegetation Index (NDVI) and the Normalized Burn Ratio (NBR) to obtain difference image and modifies conventional Level Set Method Chan-Vese (C-V) model with a new initial curve which results from a binary image applying K-means method on fitting errors of two near-infrared band images. Landsat 5 TM and Landsat 8 OLI data sets are used to validate the proposed method. Comparison with conventional C-V model, OSTU algorithm, Fuzzy C-mean (FCM) algorithm are made to show that the proposed approach can extract the outline curve of fire burn scar effectively and exactly. The method has higher extraction accuracy and less algorithm complexity than that of the conventional C-V model. PMID:24503563

Should early amputation impact initial fluid therapy algorithms in burns resuscitation? A retrospective analysis using 3D modelling.

PubMed

Staruch, Robert M T; Beverly, A; Lewis, D; Wilson, Y; Martin, N

2017-02-01

While the epidemiology of amputations in patients with burns has been investigated previously, the effect of an amputation on burn size and its impact on fluid management have not been considered in the literature. Fluid resuscitation volumes are based on the percentage of the total body surface area (%TBSA) burned calculated during the primary survey. There is currently no consensus as to whether the fluid volumes should be recalculated after an amputation to compensate for the new body surface area. The aim of this study was to model the impact of an amputation on burn size and predicted fluid requirement. A retrospective search was performed of the database at the Queen Elizabeth Hospital Birmingham Regional Burns Centre to identify all patients who had required an early amputation as a result of their burn injury. The search identified 10 patients over a 3-year period. Burn injuries were then mapped using 3D modelling software. BurnCase3D is a computer program that allows accurate plotting of burn injuries on a digital mannequin adjusted for height and weight. Theoretical fluid requirements were then calculated using the Parkland formula for the first 24 h, and Herndon formula for the second 24 h, taking into consideration the effects of the amputation on residual burn size. This study demonstrated that amputation can have an unpredictable effect on burn size that results in a significant deviation from predicted fluid resuscitation volumes. This discrepancy in fluid estimation may cause iatrogenic complications due to over-resuscitation in burn-injured casualties. Combining a more accurate estimation of postamputation burn size with goal-directed fluid therapy during the resuscitation phase should enable burn care teams to optimise patient outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Lessons from the fires of 2000: Post-fire heterogeneity in ponderosa pine forests

USGS Publications Warehouse

Kotliar, Natasha B.; Haire, Sandra L.; Key, Carl H.; Omni, Phillip N.; Joyce, Linda A.

2003-01-01

We evaluate burn-severity patterns for six burns that occurred in the southern Rocky Mountains and the Colorado Plateau in 2000. We compare the results of two data sources: Burned Area Rehabilitations Teams (BAER) and a spatial burnseverity model derived from satellite imagery (the Normalized Burn Ratio; NBR). BAER maps tended to overestimate area of severe burns and underestimate area of moderate-severity burns relative to NBR maps. Low elevation and more southern ponderosa pine burns were predominantly understory burns, whereas burns at higher elevations and farther north had a greater component of high-severity burns. Thus, much, if not most, of the area covered by these burns appears to be consistent with historic burns and contributes to healthy functioning ecosystems.

Relative importance of fuel management, ignition management and weather for area burned: Evidence from five landscape-fire-succession models

Treesearch

Geoffrey J. Cary; Mike D. Flannigan; Robert E. Keane; Ross A. Bradstock; Ian D. Davies; James M. Lenihan; Chao Li; Kimberley A. Logan; Russell A. Parsons

2009-01-01

The behaviour of five landscape fire models (CAFE, FIRESCAPE, LAMOS(HS), LANDSUM and SEMLAND) was compared in a standardised modelling experiment. The importance of fuel management approach, fuel management effort, ignition management effort and weather in determining variation in area burned and number of edge pixels burned (a measure of potential impact on assets...

[Wound healing is still a game of " blind men and an elephant"].

PubMed

Han, C M

2016-10-20

The wound healing includes non-healing and overhealing of the wounds. The results of wound healing are well known by people such as non-healing of the diabetic ulcer or hypertrophic scar after deep burn. In this issue, three papers involve in wound healing, one about autologous adipose-derived mesenchymal stem cells injected into wound or scar of rabbit ear, one about severe hypoxia and hypoalbuminemia inducing human hypertrophic scar derived fibroblast apoptosis in vitro, and another about the dysfunction of protein kinase B/mammalian target of rapamycin signaling pathway contributing to the pathophysiological characteristics of diabetic skin and non-healing wound. The basic problem of hypertrophic scar study is lacking an ideal animal model. Although rabbit ear model or red Duroc pig model has been used widely for study on hypertrophic scar, they can not fully represent human dermal fibrosis after deep trauma on the skin. I recommend A novel nude mouse model of hypertrophic scarring using scratched full thickness human skin grafts recently published in Advances in Wound Care to the readers. The author emphasizes that the wound healing study is still in the situation like the game of " blind men and an elephant" .

77 FR 13582 - Disability and Rehabilitation Research Project; Burn Model Systems Centers

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-07

.... (2008). A clarion to recommit and reaffirm burn rehabilitation. Journal of Burn Care & Research, 29(3... injury. Journal of Burn Care & Research, 30(2), 294-300. Schneider, J.C., Holavanahalli, R., Helm, P... for the year of 2009. Journal of Burn Care & Research, 31(6), 836-848. Ullrich, P.M., Askay, SW...

Neurodegeneration and Vision Loss after Mild Blunt Trauma in the C57Bl/6 and DBA/2J Mouse

PubMed Central

Bricker-Anthony, Courtney; Rex, Tonia S.

2015-01-01

Damage to the eye from blast exposure can occur as a result of the overpressure air-wave (primary injury), flying debris (secondary injury), blunt force trauma (tertiary injury), and/or chemical/thermal burns (quaternary injury). In this study, we investigated damage in the contralateral eye after a blast directed at the ipsilateral eye in the C57Bl/6J and DBA/2J mouse. Assessments of ocular health (gross pathology, electroretinogram recordings, optokinetic tracking, optical coherence tomography and histology) were performed at 3, 7, 14 and 28 days post-trauma. Olfactory epithelium and optic nerves were also examined. Anterior pathologies were more common in the DBA/2J than in the C57Bl/6 and could be prevented with non-medicated viscous eye drops. Visual acuity decreased over time in both strains, but was more rapid and severe in the DBA/2J. Retinal cell death was present in approximately 10% of the retina at 7 and 28 days post-blast in both strains. Approximately 60% of the cell death occurred in photoreceptors. Increased oxidative stress and microglial reactivity was detected in both strains, beginning at 3 days post-injury. However, there was no sign of injury to the olfactory epithelium or optic nerve in either strain. Although our model directs an overpressure air-wave at the left eye in a restrained and otherwise protected mouse, retinal damage was detected in the contralateral eye. The lack of damage to the olfactory epithelium and optic nerve, as well as the different timing of cell death as compared to the blast-exposed eye, suggests that the injuries were due to physical contact between the contralateral eye and the housing chamber of the blast device and not propagation of the blast wave through the head. Thus we describe a model of mild blunt eye trauma. PMID:26148200

Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle.

PubMed

Li, Yin; Hamilton, Katherine J; Lai, Anne Y; Burns, Katherine A; Li, Leping; Wade, Paul A; Korach, Kenneth S

2014-03-01

Diethylstilbestrol (DES) is a synthetic estrogen associated with adverse effects on reproductive organs. DES-induced toxicity of the mouse seminal vesicle (SV) is mediated by estrogen receptor α (ERα), which alters expression of seminal vesicle secretory protein IV (Svs4) and lactoferrin (Ltf) genes. We examined a role for nuclear receptor activity in association with DNA methylation and altered gene expression. We used the neonatal DES exposure mouse model to examine DNA methylation patterns via bisulfite conversion sequencing in SVs of wild-type (WT) and ERα-knockout (αERKO) mice. The DNA methylation status at four specific CpGs (-160, -237, -306, and -367) in the Svs4 gene promoter changed during mouse development from methylated to unmethylated, and DES prevented this change at 10 weeks of age in WT SV. At two specific CpGs (-449 and -459) of the Ltf gene promoter, DES altered the methylation status from methylated to unmethylated. Alterations in DNA methylation of Svs4 and Ltf were not observed in αERKO SVs, suggesting that changes of methylation status at these CpGs are ERα dependent. The methylation status was associated with the level of gene expression. In addition, gene expression of three epigenetic modifiers-DNMT3A, MBD2, and HDAC2-increased in the SV of DES-exposed WT mice. DES-induced hormonal toxicity resulted from altered gene expression of Svs4 and Ltf associated with changes in DNA methylation that were mediated by ERα. Alterations in gene expression of DNMT3A, MBD2, and HDAC2 in DES-exposed male mice may be involved in mediating the changes in methylation status in the SV. Li Y, Hamilton KJ, Lai AY, Burns KA, Li L, Wade PA, Korach KS. 2014. Diethylstilbestrol (DES)-stimulated hormonal toxicity is mediated by ERα alteration of target gene methylation patterns and epigenetic modifiers (DNMT3A, MBD2, and HDAC2) in the mouse seminal vesicle. Environ Health Perspect 122:262-268; http://dx.doi.org/10.1289/ehp.1307351.

Propagation of Cutaneous Thermal Injury: A Mathematical Model

PubMed Central

Xue, Chuan; Chou, Ching-Shan; Kao, Chiu-Yen; Sen, Chandan K.; Friedman, Avner

2012-01-01

Cutaneous burn wounds represent a significant public health problem with 500,000 patients per year in the U.S. seeking medical attention. Immediately after skin burn injury, the volume of the wound burn expands due to a cascade of chemical reactions, including lipid peroxidation chain reactions. Based on these chemical reactions, the present paper develops for the first time a three-dimensional mathematical model to quantify the propagation of tissue damage within 12 hours post initial burn. We use the model to investigate the effect of supplemental antioxidant vitamin E for stopping the propagation. We show, for example, that if the production rate of vitamin E is increased, post burn, by five times the natural production in a healthy tissue, then this would slow down the lipid peroxide propagation by at least 50%. Our model is formulated in terms of differential equations, and sensitivity analysis is performed on the parameters to ensure the robustness of the results. PMID:22211391

Geldanamycin Treatment Inhibits Hemorrhage-induced Increases in KLF6 and iNOS Expression in Unresuscitated Mouse Organs: Role of Inducible HSP70

DTIC Science & Technology

2004-08-01

stress-related proteins and whether changes can be inhibited by drugs reported to provide protection from ischemia and reperfusion injury . Male Swiss...stimulated by heat stress limit injury to tissues caused by ischemia and reperfusion (34). Likewise, inhibition of nitric oxide production results in...transfer of heat shock protein 70 protects lung grafts from ischemia - reperfusion injury . Ann Thorac Surg 67: 1421–1427, 1999. 13. Kiang JG, Carr FE, Burns

Burn-center quality improvement: are burn outcomes dependent on admitting facilities and is there a volume-outcome "sweet-spot"?

PubMed

Hranjec, Tjasa; Turrentine, Florence E; Stukenborg, George; Young, Jeffrey S; Sawyer, Robert G; Calland, James F

2012-05-01

Risk factors of mortality in burn patients such as inhalation injury, patient age, and percent of total body surface area (%TBSA) burned have been identified in previous publications. However, little is known about the variability of mortality outcomes between burn centers and whether the admitting facilities or facility volumes can be recognized as predictors of mortality. De-identified data from 87,665 acute burn observations obtained from the National Burn Repository between 2003 and 2007 were used to estimate a multivariable logistic regression model that could predict patient mortality with reference to the admitting burn facility/facility volume, adjusted for differences in age, inhalation injury, %TBSA burned, and an additional factor, percent full thickness burn (%FTB). As previously reported, all three covariates (%TBSA burned, inhalation injury, and age) were found to be highly statistically significant risk factors of mortality in burn patients (P value < 0.0001). The additional variable, %FTB, was also found to be a statistically significant determinant, although it did not greatly improve the multivariable model. The treatment/admitting facility was found to be an independent mortality predictor, with certain hospitals having increased odds of death and others showing a protective effect (decreased odds ratio). Hospitals with high burn volumes had the highest risk of mortality. Mortality outcomes of patients with similar risk factors (%TBSA burned, inhalation injury, age, and %FTB) are significantly affected by the treating facility and their admission volumes.

Utilization of laser Doppler flowmetry and tissue spectrophotometry for burn depth assessment using a miniature swine model.

PubMed

Lotter, Oliver; Held, Manuel; Schiefer, Jennifer; Werner, Ole; Medved, Fabian; Schaller, Hans-Eberhard; Rahmanian-Schwarz, Afshin; Jaminet, Patrick; Rothenberger, Jens

2015-01-01

Currently, the diagnosis of burn depth is primarily based on a visual assessment and can be dependent on the surgeons' experience. The goal of this study was to determine the ability of laser Doppler flowmeter combined with a tissue spectrophotometer to discriminate burn depth in a miniature swine burn model. Burn injuries of varying depth, including superficial-partial, deep-partial, and full thickness, were created in seven Göttingen minipigs using an aluminium bar (100 °C), which was applied to the abdominal skin for periods of 1, 3, 6, 12, 30, and 60 seconds with gravity alone. The depth of injury was evaluated histologically using hematoxylin and eosin staining. All burns were assessed 3 hours after injury using a device that combines a laser light and a white light to determine blood flow, hemoglobin oxygenation, and relative amount of hemoglobin. The blood flow (41 vs. 124 arbitrary units [AU]) and relative amount of hemoglobin (32 vs. 52 AU) were significantly lower in full thickness compared with superficial-partial thickness burns. However, no significant differences in hemoglobin oxygenation were observed between these depths of burns (61 vs. 60%). These results show the ability of laser Doppler flowmeter and tissue spectrophotometer in combination to discriminate between various depths of injury in the minipig model, suggesting that this device may offer a valuable tool for burn depth assessment influencing burn management. © 2014 by the Wound Healing Society.

Development of an Animal Model for Burn-Blast Combined Injury and Cardiopulmonary System Changes in the Early Shock Stage.

PubMed

Hu, Quan; Chai, Jiake; Hu, Sen; Fan, Jun; Wang, Hong-Wei; Ma, Li; Duan, Hong-Jie; Liu, Lingying; Yang, Hongming; Li, Bai-Ling; Wang, Yi-He

2015-12-01

The purposes of this study were to establish an animal model for burn-blast combined injury research and elaborate cardiopulmonary system changes in the early shock stage. In this study, royal demolition explosive or RDX (hexagon, ring trimethylene nitramine) was used as an explosive source, and the injury conditions of the canine test subjects at various distances to the explosion (30, 50, and 70 cm) were observed by gross anatomy and pathology to determine a larger animal model of moderate blast injury. The canines were then subjected to a 35 % total body surface area (TBSA) full-thickness flame injury using napalm, which completed the development of a burn-blast combined injury model. Based on this model, the hemodynamic changes and arterial blood gas analysis after the burn-blast combined injury were measured to identify the cardiopulmonary system characteristics. In this research, RDX explosion and flame injury were used to develop a severe burn-blast injury animal model that was stable, close to reality, and easily controllable. The hemodynamic and arterial blood gas changes in the canine subjects after burn-blast injury changed distinctly from the burn and blast injuries. Blood pressure and cardiac output fluctuated, and the preload was significantly reduced, whereas the afterload significantly increased. Meanwhile, the oxygen saturation (SO2) decreased markedly with carbon dioxide partial pressure (PCO2), and lactic acid (Lac) rose, and oxygen partial pressure (PO2) reduced. These changes suggested that immediate clinical treatment is important during burn-blast injury both to stabilize cardiac function and supply blood volume and to reduce the vascular permeability, thereby preventing acute pneumonedema or other complications.

Vagus nerve stimulation blocks vascular permeability following burn injury in both local and distal sites

PubMed Central

Ortiz-Pomales, Yan T; Krzyzaniak, Michael; Coimbra, Raul; Baird, Andrew; Eliceiri, Brian P.

2012-01-01

Recent studies have shown that vagus nerve stimulation (VNS) can block the burn injury-induced systemic inflammatory response (SIRS). In this study we examined the potential for VNS to modulate vascular permeability (VP) in local sites (i.e. skin) and in secondary sites (i.e. lung) following burn injury. In a 30% total body surface area burn injury model, VP was measured using intravascular fluorescent dextran for quantification of the VP response in skin and lung. A peak in VP of the skin was observed 24 hours post-burn injury, that was blocked by VNS. Moreover, in the lung, VNS led to a reduction in burn-induced VP compared to sham-treated animals subjected to burn injury alone. The protective effects of VNS in this model were independent of the spleen, suggesting that the spleen was not a direct mediator of VNS. These studies identify a role for VNS in the regulation of VP in burns, with the translational potential of attenuating lung complications following burn injury. PMID:22694873

Quantitative Assessment of Graded Burn Wounds in a Porcine Model using Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI)

DTIC Science & Technology

2014-09-08

used SFDI and LSI to investigate controlled burn wounds of graded severity in a Yorkshire pig model. Burn wounds were imaged starting at one hour...10–15 (1992). 39. M. Chvapil, D. P. Speer, J. A. Owen, and T. A. Chvapil, “Identification of the depth of burn injury by collagen stainability... collagen denaturation (via scattering changes), hemodynamics and vascular damage each of which have the potential to provide clinicians with

Experimental and Analytical Study of Erosive Burning of Solid Propellants

DTIC Science & Technology

1981-06-01

Identity by block number) Experirnert~iI - d analytical, *bdeling studies of the erosive burning ,..solfd propel l;n!t; w’r(, ,conducted at Atlantic Research...is approved for public ’release IAVV AFR 190-12 (Tb). Distribuiiou is unlitited. A. D . HLOSE Z Tecuhtgal Ina’o ’nation Offo icer - 3. Conduct...roughness. 8. Extend the erosive burning model from flat-plate geometry to axisymmetric flow. 9. Validate the 2- D model of erosive burning by experimental

Modeling biomass burning emissions for Amazon forest and pastures in Rondônia, Brazil.

Treesearch

Liane S. Guild; J. Boone Kauffman; Warren B. Cohen; Christine A. Hlavka; Darold E. Ward

2004-01-01

As a source of atmospheric carbon, biomass burning emissions associated with deforestation in the Amazon are globally significant. Once deforested, these lands continue to be sources of substantial burning emissions for many years due to frequent pasture burning. The objective of this research was to quantify biomass-burning emissions at a local scale. We estimated...

Analysis of Alaskan burn severity patterns using remotely sensed data

USGS Publications Warehouse

Duffy, P.A.; Epting, J.; Graham, J.M.; Rupp, T.S.; McGuire, A.D.

2007-01-01

Wildland fire is the dominant large-scale disturbance mechanism in the Alaskan boreal forest, and it strongly influences forest structure and function. In this research, patterns of burn severity in the Alaskan boreal forest are characterised using 24 fires. First, the relationship between burn severity and area burned is quantified using a linear regression. Second, the spatial correlation of burn severity as a function of topography is modelled using a variogram analysis. Finally, the relationship between vegetation type and spatial patterns of burn severity is quantified using linear models where variograms account for spatial correlation. These results show that: 1) average burn severity increases with the natural logarithm of the area of the wildfire, 2) burn severity is more variable in topographically complex landscapes than in flat landscapes, and 3) there is a significant relationship between burn severity and vegetation type in flat landscapes but not in topographically complex landscapes. These results strengthen the argument that differential flammability of vegetation exists in some boreal landscapes of Alaska. Additionally, these results suggest that through feedbacks between vegetation and burn severity, the distribution of forest vegetation through time is likely more stable in flat terrain than it is in areas with more complex topography. ?? IAWF 2007.

Projecting climate-driven increases in North American fire activity

NASA Astrophysics Data System (ADS)

Wang, D.; Morton, D. C.; Collatz, G. J.

2013-12-01

Climate regulates fire activity through controls on vegetation productivity (fuels), lightning ignitions, and conditions governing fire spread. In many regions of the world, human management also influences the timing, duration, and extent of fire activity. These coupled interactions between human and natural systems make fire a complex component of the Earth system. Satellite data provide valuable information on the spatial and temporal dynamics of recent fire activity, as active fires, burned area, and land cover information can be combined to separate wildfires from intentional burning for agriculture and forestry. Here, we combined satellite-derived burned area data with land cover and climate data to assess fire-climate relationships in North America between 2000-2012. We used the latest versions of the Global Fire Emissions Database (GFED) burned area product and Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate data to develop regional relationships between burned area and potential evaporation (PE), an integrated dryness metric. Logistic regression models were developed to link burned area with PE and individual climate variables during and preceding the fire season, and optimal models were selected based on Akaike Information Criterion (AIC). Overall, our model explained 85% of the variance in burned area since 2000 across North America. Fire-climate relationships from the era of satellite observations provide a blueprint for potential changes in fire activity under scenarios of climate change. We used that blueprint to evaluate potential changes in fire activity over the next 50 years based on twenty models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). All models suggest an increase of PE under low and high emissions scenarios (Representative Concentration Pathways (RCP) 4.5 and 8.5, respectively), with largest increases in projected burned area across the western US and central Canada. Overall, near-term climate projections point to pronounced changes in fire season length, total burned area, and the frequency of extreme events across North America by 2050.

Development of the ClearSky smoke dispersion forecast system for agricultural field burning in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Jain, Rahul; Vaughan, Joseph; Heitkamp, Kyle; Ramos, Charleston; Claiborn, Candis; Schreuder, Maarten; Schaaf, Mark; Lamb, Brian

The post-harvest burning of agricultural fields is commonly used to dispose of crop residue and provide other desired services such as pest control. Despite careful regulation of burning, smoke plumes from field burning in the Pacific Northwest commonly degrade air quality, particularly for rural populations. In this paper, ClearSky, a numerical smoke dispersion forecast system for agricultural field burning that was developed to support smoke management in the Inland Pacific Northwest, is described. ClearSky began operation during the summer through fall burn season of 2002 and continues to the present. ClearSky utilizes Mesoscale Meteorological Model version 5 (MM5v3) forecasts from the University of Washington, data on agricultural fields, a web-based user interface for defining burn scenarios, the Lagrangian CALPUFF dispersion model and web-served animations of plume forecasts. The ClearSky system employs a unique hybrid source configuration, which treats the flaming portion of a field as a buoyant line source and the smoldering portion of the field as a buoyant area source. Limited field observations show that this hybrid approach yields reasonable plume rise estimates using source parameters derived from recent field burning emission field studies. The performance of this modeling system was evaluated for 2003 by comparing forecast meteorology against meteorological observations, and comparing model-predicted hourly averaged PM 2.5 concentrations against observations. Examples from this evaluation illustrate that while the ClearSky system can accurately predict PM 2.5 surface concentrations due to field burning, the overall model performance depends strongly on meteorological forecast error. Statistical evaluation of the meteorological forecast at seven surface stations indicates a strong relationship between topographical complexity near the station and absolute wind direction error with wind direction errors increasing from approximately 20° for sites in open areas to 70° or more for sites in very complex terrain. The analysis also showed some days with good forecast meteorology with absolute mean error in wind direction less than 30° when ClearSky correctly predicted PM 2.5 surface concentrations at receptors affected by field burns. On several other days with similar levels of wind direction error the model did not predict apparent plume impacts. In most of these cases, there were no reported burns in the vicinity of the monitor and, thus, it appeared that other, non-reported burns were responsible for the apparent plume impact at the monitoring site. These cases do not provide information on the performance of the model, but rather indicate that further work is needed to identify all burns and to improve burn reports in an accurate and timely manner. There were also a number of days with wind direction errors exceeding 70° when the forecast system did not correctly predict plume behavior.

Burns to the genitalia, perineum, and buttocks increase the risk of death among U.S. service members sustaining combat-related burns in Iraq and Afghanistan.

PubMed

Clemens, Michael S; Janak, Judson C; Rizzo, Julie A; Graybill, John C; Buehner, Michelle F; Hudak, Steven J; Thompson, Charles K; Chung, Kevin K

2017-08-01

Among service members injured in Iraq and Afghanistan, to determine the risk of mortality associated with combat-related burns to the genitalia, perineum, and buttocks. The prospectively maintained burn registry from the United States Army Institute of Surgical Research was retrospectively reviewed to identify all service members with combat-related burns sustained in Iraq and Afghanistan from March 2003 to October 2013. The two primary risk factors of interest were (1) any burn to the genitals, perineum, and/or buttocks (PB) and (2) burns involving the entire perineal, genital, and buttock region (complete PB). Cox proportional hazard models were used to estimate the risk of mortality for both primary risk factors, and adjusted for severe non-burn-related trauma, percent of burn over total body surface area (TBSA), inhalational injury, time to urinary tract infection, and time to bacteremia. A post-hoc analysis was performed to explore the potential effect modification of TBSA burned on the relationship between PB and mortality. Among the 902 U.S. service members with combat-related burns sustained during the study period, 226 (25.0%) had involvement of the genitalia, perineum, and/or buttocks. Complete PB was associated with a crude risk of mortality (HR: 5.3; 2.9-9.7), but not an adjusted risk (HR=1.8; 0.8-4.0). However, TBSA burned was identified as a potential negative effect modifier. Among patients with burns <60% TBSA, sustaining a complete PB conferred an adjusted risk of death (HR=2.7; 1.1-6.8). Further, patients with a perineal burn had a five-fold increased incidence of bacteremia. In adjusted models, each event of bacteremia increased the risk of mortality by 92% (HR 1.92; 1.39-2.65). Perineal burns were associated with a two-fold increased incidence of severe non-burn related trauma that also doubled mortality risk in adjusted models (HR 2.29; 1.23-4.27). Among those with relatively survivable combat-related burns (<60% TBSA), genital/perineal/buttock involvement increases the risk of death. Bacteremia may account for part of this increased risk, but does not fully explain the independent risk associated with perineal burns. Published by Elsevier Ltd.

Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

DTIC Science & Technology

2015-10-15

between p38MAPK signaling, wound inflammatory response, wound healing and long-term scar formation using a burn model in the female red Duroc pig ... pig model burn model as the appropriate wound healing model that resembles human response. At the end of the project, we will have a well-defined animal...scarring (period before the award of the current grant). Table 1 Study ID Wound Dates Treatment Pigs # Duration of study Pg001 Dermatome Feb

Topical Modulation of the Burn Wound Inflammatory Response to Improve Short and Long Term Outcomes

DTIC Science & Technology

2015-10-01

between p38MAPK signaling, wound inflammatory response, wound healing and long-term scar formation using a burn model in the female red Duroc pig ... pig model burn model as the appropriate wound healing model that resembles human response. At the end of the project, we will have a well-defined animal...scarring (period before the award of the current grant). Table 1 Study ID Wound Dates Treatment Pigs # Duration of study Pg001 Dermatome Feb

Modelling fire frequency and area burned across phytoclimatic regions in Spain using reanalysis data and the Canadian Fire Weather Index System

NASA Astrophysics Data System (ADS)

Bedia, J.; Herrera, S.; Gutiérrez, J. M.

2013-09-01

We develop fire occurrence and burned area models in peninsular Spain, an area of high variability in climate and fuel types, for the period 1990-2008. We based the analysis on a phytoclimatic classification aiming to the stratification of the territory into homogeneous units in terms of climatic and fuel type characteristics, allowing to test model performance under different climatic and fuel conditions. We used generalized linear models (GLM) and multivariate adaptive regression splines (MARS) as modelling algorithms and temperature, relative humidity, precipitation and wind speed, taken from the ERA-Interim reanalysis, as well as the components of the Canadian Forest Fire Weather Index (FWI) System as predictors. We also computed the standardized precipitation-evapotranspiration index (SPEI) as an additional predictor for the models of burned area. We found two contrasting fire regimes in terms of area burned and number of fires: one characterized by a bimodal annual pattern, characterizing the Nemoral and Oro-boreal phytoclimatic types, and another one exhibiting an unimodal annual cycle, with the fire season concentrated in the summer months in the Mediterranean and Arid regions. The fire occurrence models attained good skill in most of the phytoclimatic zones considered, yielding in some zones notably high correlation coefficients between the observed and modelled inter-annual fire frequencies. Total area burned also exhibited a high dependence on the meteorological drivers, although their ability to reproduce the observed annual burned area time series was poor in most cases. We identified temperature and some FWI system components as the most important explanatory variables, and also SPEI in some of the burned area models, highlighting the adequacy of the FWI system for fire modelling applications and leaving the door opened to the development a more complex modelling framework based on these predictors. Furthermore, we demonstrate the potential usefulness of ERA-Interim reanalysis data for the reconstruction of historical fire-climate relationships at the scale of analysis. Fire frequency predictions may provide a preferable basis for past fire history reconstruction, long-term monitoring and the assessment of future climate impacts on fire regimes across regions, posing several advantages over burned area as response variable.

Building a balanced scorecard for a burn center.

PubMed

Wachtel, T L; Hartford, C E; Hughes, J A

1999-08-01

The Balanced Scorecard provides a model that can be adapted to the management of any burn center, burn service or burn program. This model enables an organization to translate its mission and vision into specific strategic objectives across the four perspective: (1) the financial perspective; (2) the customer service perspective; (3) the internal business perspective; and (4) the growth and learning perspective. Once the appropriate objectives are identified, the Balanced Scorecard guides the organization to develop reasonable performance measures and establishes targets, initiatives and alternatives to meet programmatic goals and pursue longer-term visionary improvements. We used the burn center at the University of Colorado Health Sciences Center to test whether the Balanced Scorecard methodology was appropriate for the core business plan of a healthcare strategic business unit (i.e. a burn center).

Toll-Like Receptor Signaling in Burn Wound Healing and Scarring

PubMed Central

D'Arpa, Peter; Leung, Kai P.

2017-01-01

Significance: Damage-associated molecular patterns (DAMPs) and pathogen-associated molecular patterns (PAMPs) emanate from burn-injured tissue and enter systemic circulation. Locally and systemically, they activate pattern-recognition receptors, including toll-like receptors (TLRs), to stimulate cytokine secretion, which in the severest burns typically results in extreme systemic cytokine levels, a dysfunctioning immune system, infection, impaired healing, and excessive scarring. This system-wide disruption of homeostasis can advance to life-threatening, multiorgan dysfunction syndrome. Knowledge of DAMP- and PAMP-TLR signaling may lead to treatments that ameliorate local and systemic inflammation and reduce scarring and other burn injury sequela. Recent Advances: Many PAMPs and DAMPs, the TLRs they activate, and their downstream signaling molecules have been shown to contribute to local and systemic inflammation and tissue damage following burn injury. Critical Issues: Whether TLR-pathway-targeting treatments applied at different times postburn injury might improve scarring remains an open question. The evaluation of this question requires the use of appropriate preclinical and clinical burn models carried out until after mature scar has formed. Future Directions: After TLR-pathway-targeting treatments are evaluated in porcine burn wound models and their safety is demonstrated, they can be tested in proof-of-concept clinical burn wound models. PMID:29062590

[Estimating Biomass Burned Areas from Multispectral Dataset Detected by Multiple-Satellite].

PubMed

Yu, Chao; Chen, Liang-fu; Li, Shen-shen; Tao, Jin-hua; Su, Lin

2015-03-01

Biomass burning makes up an important part of both trace gases and particulate matter emissions, which can efficiently degrade air quality and reduce visibility, destabilize the global climate system at regional to global scales. Burned area is one of the primary parameters necessary to estimate emissions, and considered to be the largest source of error in the emission inventory. Satellite-based fire observations can offer a reliable source of fire occurrence data on regional and global scales, a variety of sensors have been used to detect and map fires in two general approaches: burn scar mapping and active fire detection. However, both of the two approaches have limitations. In this article, we explore the relationship between hotspot data and burned area for the Southeastern United States, where a significant amount of biomass burnings from both prescribed and wild fire took place. MODIS (Moderate resolution imaging spectrometer) data, which has high temporal-resolution, can be used to monitor ground biomass. burning in time and provided hot spot data in this study. However, pixel size of MODIS hot spot can't stand for the real ground burned area. Through analysis of the variation of vegetation band reflectance between pre- and post-burn, we extracted the burned area from Landsat-5 TM (Thematic Mapper) images by using the differential normalized burn ratio (dNBR) which is based on TM band4 (0.84 μm) and TM band 7(2.22 μm) data. We combined MODIS fire hot spot data and Landsat-5 TM burned scars data to build the burned area estimation model, results showed that the linear correlation coefficient is 0.63 and the relationships vary as a function of vegetation cover. Based on the National Land Cover Database (NLCD), we built burned area estimation model over different vegetation cover, and got effective burned area per fire pixel, values for forest, grassland, shrub, cropland and wetland are 0.69, 1.27, 0.86, 0.72 and 0.94 km2 respectively. We validated the burned area estimates by using the ground survey data from National interagency Fire Center (NIFC), our results are more close to the ground survey data than burned area from Global Fire Emissions Database (GFED) and MODIS burned area product (MCD45), which omitted many small prescribed fires. We concluded that our model can provide more accurate burned area parameters for developing fire emission inventory, and be better for estimating emissions from biomass burning.

A polygon-based modeling approach to assess exposure of resources and assets to wildfire

Treesearch

Matthew P. Thompson; Joe Scott; Jeffrey D. Kaiden; Julie W. Gilbertson-Day

2013-01-01

Spatially explicit burn probability modeling is increasingly applied to assess wildfire risk and inform mitigation strategy development. Burn probabilities are typically expressed on a per-pixel basis, calculated as the number of times a pixel burns divided by the number of simulation iterations. Spatial intersection of highly valued resources and assets (HVRAs) with...

Burn severity mapping using simulation modeling and satellite imagery

Treesearch

Eva C. Karau; Robert E. Keane

2010-01-01

Although burn severity maps derived from satellite imagery provide a landscape view of fire impacts, fire effects simulation models can provide spatial fire severity estimates and add a biotic context in which to interpret severity. In this project, we evaluated two methods of mapping burn severity in the context of rapid post-fire assessment for four wildfires in...

Modeling crop residue burning experiments to evaluate smoke emissions and plume transport

Treesearch

Luxi Zhou; Kirk R. Baker; Sergey L. Napelenok; George Pouliot; Robert Elleman; Susan M. O' Neill; Shawn P. Urbanski; David C. Wong

2018-01-01

Crop residue burning is a common land management practice that results in emissions of a variety of pollutants with negative health impacts. Modeling systems are used to estimate air quality impacts of crop residue burning to support retrospective regulatory assessments and also for forecasting purposes. Ground and airborne measurements from a recent field experiment...

An improved model for the combustion of AP composite propellants

NASA Technical Reports Server (NTRS)

Cohen, N. S.; Strand, L. D.

1981-01-01

This paper presents several improvements to the BDP model of steady-state burning of AP composite solid propellants. The Price-Boggs-Derr model of AP monopropellant burning is incorporated to represent the AP. A separate energy equation is written for the binder to permit a different surface temperature from the AP; this includes an analysis of the sharing of primary diffusion flame energy, and correction of a BDP model inconsistency in treating the binder regression rate. A method for assembling component contributions to calculate the burning rates of multimodal propellants is also presented. Results are shown in the form of representative burning rate curves, comparisons with data, and calculated internal details of interest. Ideas for future work are discussed in an Appendix.

A Preliminary Assessment of the SURF Reactive Burn Model Implementation in FLAG

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Carl Edward; McCombe, Ryan Patrick; Carver, Kyle

Properly validated and calibrated reactive burn models (RBM) can be useful engineering tools for assessing high explosive performance and safety. Experiments with high explosives are expensive. Inexpensive RBM calculations are increasingly relied on for predictive analysis for performance and safety. This report discusses the validation of Menikoff and Shaw’s SURF reactive burn model, which has recently been implemented in the FLAG code. The LANL Gapstick experiment is discussed as is its’ utility in reactive burn model validation. Data obtained from pRad for the LT-63 series is also presented along with FLAG simulations using SURF for both PBX 9501 and PBXmore » 9502. Calibration parameters for both explosives are presented.« less

Thyroid Function in Critical Illness and Burn Injury,

DTIC Science & Technology

1993-07-01

measrent of tyida x hor-etioogyof hperhyridis, Oive Cop eta15 mones in burn patients and animal burn models etiology of hyperthyroidism , Oliver Cope et...post-burn hypermetabolic condition following major burns.’ ൡ In fact, the opposite is a function of transient hyperthyroidism . They question of...concluded that hyperthyroidism was not present protracted illness, whether medical, surgical, and was not the mediator of the hypermetabol- or

Single hind limb burn injury to mice alters nuclear factor-κB expression and [¹⁸F] 2-fluoro-2-deoxy-D-glucose uptake.

PubMed

Carter, Edward A; Hamrahi, Victoria; Paul, Kasie; Bonab, Ali A; Jung, Walter; Tompkins, Ronald G; Fischman, Alan J

2014-01-01

Burn trauma to the extremities can produce marked systemic effects in mice. Burn injury to the dorsal surface of mice is also associated with changes in glucose metabolism ([18F] 2-fluoro-2-deoxy-D-glucose [18FDG] uptake) by brown adipose tissue (BAT) and nuclear factor (NF)-κB activity in several tissues including skeletal muscle. This study examined the effect of a single hind limb burn in mice on 18FDG uptake by NF-κB activity in vivo, and blood flow was determined by laser Doppler techniques. Male NF-κB luciferase reporter mice (28-30 g) were anesthetized, both legs were shaven, and the right leg was subjected to scald injury by immersion in 90°C water for 5 seconds. Sham-treated animals were used as controls. Each burned and sham mouse was resuscitated with saline (2 mL, i.p.). The individual animals were placed in wire bottom cages with no food and free access to water. After 24 hours, the animals were imaged with laser Doppler for measuring blood flow in the hind limb. The animals were then unanesthetized with 50 μCi of FDG or luciferin (1.0 mg, i.v.) via tail vein. Five minutes after luciferin injection, NF-κB mice were studied by bioluminescence imaging with a charge-coupled device camera. One hour after 18FDG injection, the animals were killed with carbon dioxide overdose, and 18FDG biodistribution was measured. Tissues were also analyzed for NF-κB luciferase activity. The scalding procedure used here produced a full-thickness burn injury to the leg with sharp margins. 18FDG uptake by the burned leg was lower than that in the contralateral limb. Similarly, luciferase activity and blood flow in the burned leg were lower than those in the contralateral leg. 18FDG uptake by BAT and heart increased, whereas that by brain decreased. In conclusion, the present study suggests that burn injury to a single leg decreased FDG uptake by skeletal muscle but increased 18FDG uptake by BAT. The injury to the leg reduced NF-κB expression compared with the contralateral leg and the uninjured skeletal muscle of the sham but activated NF-κB expression in a number of other organs. These findings are consistent with the hypothesis that burn trauma to the extremities can produce marked systemic effects, including activation of NF-κB expression and activation of 18FDG uptake by BAT.

Single Hind Limb Burn Injury to Mice Alters NF Kappa B (NF-κB) Expression and [18F] 2-Fluoro-2-Deoxy-d-Glucose (FDG) Uptake

PubMed Central

Carter, Edward A.; Hamrahi, Victoria; Paul, Kasie; Bonab, Ali A.; Jung, Walter; Tompkins, Ronald G.; Fischman, Alan J.

2014-01-01

Burn trauma to the extremities can produce marked systemic effects in mice1, 6, 7. Burn injury to the dorsal surface of mice is also associated with changes in glucose metabolism (18FDG uptake) by brown adipose tissue (BAT) and NF-κB activity in a number of tissues including skeletal muscle. This study examined the effect of a single hindlimb burn in mice on 18FDG uptake by in vivo, NF-κB activity in vivo, and blood flow determined by laser Doppler techniques. Male mice NF-κB luciferase reporter mice (28 grams- 30 grams, male) were anesthetized, both legs were shaven, and the right leg was subjected to scald injury by immersion in 90°C water for 5 seconds. Sham treated animals were used as controls. Each burned and sham mouse was resuscitated with saline (2 ml, IP). The individual animals were placed in wire bottom cages with no food and free access to water. 24 hrs later, the animals were imaged with Laser Doppler for measurements of blood flow in the hind limb. The animals were then injected unanesthetized with 50 µCi of FDG or luciferin (1.0 mg), I.V. via tail vein. Five minutes after luciferin injection, NF-kB mice were studied by bioluminescence imaging with a CCD camera. One hour after 18FDG injection the animals were euthanized with carbon dioxide overdose and 18FDG biodistribution was measured. Tissues were also analyzed for NF-κB luciferase activity. The scalding procedure used here produced a full thickness burn injury to the leg with sharp margins. 18FDG uptake by the burned leg was lower than in the contralateral limb. Similarly luciferase activity and blood flow in the burned leg were lower than in the contralateral leg. 18FDG uptake by BAT and heart was increased, while brain was decreased. In conclusion, the present study suggests that burn injury to a single leg reduced 18FDG uptake by skeletal muscle but increased 18FDG uptake by BAT. The injury to the leg reduced NF-κB expression as compared to the contralateral leg and the uninjured skeletal muscle of the sham, but activated NF-κB expression in a number of other organs. These findings are consistent with the hypothesis that burn trauma to the extremities can produce marked systemic effects, including activation of NF-κB expression and activation of 18FDG uptake by BAT. PMID:25100541

Local Burn-Up Effects in the NBSR Fuel Element

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown N. R.; Hanson A.; Diamond, D.

2013-01-31

This study addresses the over-prediction of local power when the burn-up distribution in each half-element of the NBSR is assumed to be uniform. A single-element model was utilized to quantify the impact of axial and plate-wise burn-up on the power distribution within the NBSR fuel elements for both high-enriched uranium (HEU) and low-enriched uranium (LEU) fuel. To validate this approach, key parameters in the single-element model were compared to parameters from an equilibrium core model, including neutron energy spectrum, power distribution, and integral U-235 vector. The power distribution changes significantly when incorporating local burn-up effects and has lower power peakingmore » relative to the uniform burn-up case. In the uniform burn-up case, the axial relative power peaking is over-predicted by as much as 59% in the HEU single-element and 46% in the LEU single-element with uniform burn-up. In the uniform burn-up case, the plate-wise power peaking is over-predicted by as much as 23% in the HEU single-element and 18% in the LEU single-element. The degree of over-prediction increases as a function of burn-up cycle, with the greatest over-prediction at the end of Cycle 8. The thermal flux peak is always in the mid-plane gap; this causes the local cumulative burn-up near the mid-plane gap to be significantly higher than the fuel element average. Uniform burn-up distribution throughout a half-element also causes a bias in fuel element reactivity worth, due primarily to the neutronic importance of the fissile inventory in the mid-plane gap region.« less

Using Logistic Regression To Predict the Probability of Debris Flows Occurring in Areas Recently Burned By Wildland Fires

USGS Publications Warehouse

Rupert, Michael G.; Cannon, Susan H.; Gartner, Joseph E.

2003-01-01

Logistic regression was used to predict the probability of debris flows occurring in areas recently burned by wildland fires. Multiple logistic regression is conceptually similar to multiple linear regression because statistical relations between one dependent variable and several independent variables are evaluated. In logistic regression, however, the dependent variable is transformed to a binary variable (debris flow did or did not occur), and the actual probability of the debris flow occurring is statistically modeled. Data from 399 basins located within 15 wildland fires that burned during 2000-2002 in Colorado, Idaho, Montana, and New Mexico were evaluated. More than 35 independent variables describing the burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated. The models were developed as follows: (1) Basins that did and did not produce debris flows were delineated from National Elevation Data using a Geographic Information System (GIS). (2) Data describing the burn severity, geology, land surface gradient, rainfall, and soil properties were determined for each basin. These data were then downloaded to a statistics software package for analysis using logistic regression. (3) Relations between the occurrence/non-occurrence of debris flows and burn severity, geology, land surface gradient, rainfall, and soil properties were evaluated and several preliminary multivariate logistic regression models were constructed. All possible combinations of independent variables were evaluated to determine which combination produced the most effective model. The multivariate model that best predicted the occurrence of debris flows was selected. (4) The multivariate logistic regression model was entered into a GIS, and a map showing the probability of debris flows was constructed. The most effective model incorporates the percentage of each basin with slope greater than 30 percent, percentage of land burned at medium and high burn severity in each basin, particle size sorting, average storm intensity (millimeters per hour), soil organic matter content, soil permeability, and soil drainage. The results of this study demonstrate that logistic regression is a valuable tool for predicting the probability of debris flows occurring in recently-burned landscapes.

Caring for burn patients at the United States Institute of Surgical Research: the nurses' multifaceted roles.

PubMed

Serio-Melvin, Maria; Yoder, Linda H; Gaylord, Kathryn M

2010-06-01

Nursing plays a critical role in the comprehensive burn care delivered at the US Army Institute of Surgical Research, otherwise known as the US Army's Burn Center serving the Department of Defense. This center serves as a model for burn units nationally and internationally. It also provides a challenging and innovative work environment for military and civilian nurses. Nurses in the Burn Center contribute to innovations in acute, rehabilitative, and psychological care for patients with burns. This article provides an overview of the complex nursing care provided to burn patients treated at the Burn Center. Copyright (c) 2010 Elsevier Inc. All rights reserved.

The use of an atmospheric dispersion model to determine influence regions in the Prince George, B.C. airshed from the burning of open wood waste piles.

PubMed

Ainslie, B; Jackson, P L

2009-06-01

A means of determining air emission source regions adversely influencing the city of Prince George, British Columbia, Canada from potential burning of isolated piles of mountain pine beetle-killed lodge pole pine is presented. The analysis uses the CALPUFF atmospheric dispersion model to identify safe burning regions based on atmospheric stability and wind direction. Model results show that the location and extent of influence regions is sensitive to wind speed, wind direction, atmospheric stability and a threshold used to quantify excessive concentrations. A concentration threshold based on the Canada Wide PM(2.5) Standard is used to delineate the influence regions while Environment Canada's (EC) daily ventilation index (VI) is used to quantify local atmospheric stability. Results from the analysis, to be used by air quality meteorologists in assessing daily requests for burning permits, are presented as a series of maps delineating acceptable burning locations for sources placed at various distances from the city center and under different ventilation conditions. The results show that no burning should be allowed within 10 km of the city center; under poor ventilation conditions, no burning should be allowed within 20 km of the city center; under good ventilation conditions, burning can be allowed within 10-15 km of the city center; under good to fair ventilation conditions, burning can be allowed beyond 15 km of the city center; and if the wind direction can be reliably forecast, burning can be allowed between 5 and 10 km downwind of the city center under good ventilation conditions.

Hot soup! Correlating the severity of liquid scald burns to fluid and biomedical properties.

PubMed

Loller, Cameron; Buxton, Gavin A; Kerzmann, Tony L

2016-05-01

Burns caused by hot drinks and soups can be both debilitating and costly, especially to pediatric and geriatric patients. This research is aimed at better understanding the fluid properties that can influence the severity of skin burns. We use a standard model which combines heat transfer and biomedical equations to predict burn severity. In particular, experimental data from a physical model serves as the input to our numerical model to determine the severity of scald burns as a consequence of actual fluid flows. This technique enables us to numerically predict the heat transfer from the hot soup into the skin, without the need to numerically estimate the complex fluid mechanics and thermodynamics of the potentially highly viscous and heterogeneous soup. While the temperature of the soup is obviously is the most important fact in determining the degree of burn, we also find that more viscous fluids result in more severe burns, as the slower flowing thicker fluids remain in contact with the skin for longer. Furthermore, other factors can also increase the severity of burn such as a higher initial fluid temperature, a greater fluid thermal conductivity, or a higher thermal capacity of the fluid. Our combined experimental and numerical investigation finds that for average skin properties a very viscous fluid at 100°C, the fluid must be in contact with the skin for around 15-20s to cause second degree burns, and more than 80s to cause a third degree burn. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Sensitivity of burned area in Europe to climate change, atmospheric CO2 levels, and demography: A comparison of two fire-vegetation models

NASA Astrophysics Data System (ADS)

Wu, Minchao; Knorr, Wolfgang; Thonicke, Kirsten; Schurgers, Guy; Camia, Andrea; Arneth, Almut

2015-11-01

Global environmental changes and human activity influence wildland fires worldwide, but the relative importance of the individual factors varies regionally and their interplay can be difficult to disentangle. Here we evaluate projected future changes in burned area at the European and sub-European scale, and we investigate uncertainties in the relative importance of the determining factors. We simulated future burned area with LPJ-GUESS-SIMFIRE, a patch-dynamic global vegetation model with a semiempirical fire model, and LPJmL-SPITFIRE, a dynamic global vegetation model with a process-based fire model. Applying a range of future projections that combine different scenarios for climate changes, enhanced CO2 concentrations, and population growth, we investigated the individual and combined effects of these drivers on the total area and regions affected by fire in the 21st century. The two models differed notably with respect to the dominating drivers and underlying processes. Fire-vegetation interactions and socioeconomic effects emerged as important uncertainties for future burned area in some European regions. Burned area of eastern Europe increased in both models, pointing at an emerging new fire-prone region that should gain further attention for future fire management.

Generation of human-induced pluripotent stem cells from burn patient-derived skin fibroblasts using a non-integrative method.

PubMed

Fu, Shangfeng; Ding, Jianwu; Liu, Dewu; Huang, Heping; Li, Min; Liu, Yang; Tu, Longxiang; Liu, Deming

2018-01-01

Patient specific induced pluripotent stem cells (iPSCs) have been recognized as a possible source of cells for skin tissue engineering. They have the potential to greatly benefit patients with large areas of burned skin or skin defects. However, the integration virus-based reprogramming method is associated with a high risk of genetic mutation and mouse embryonic fibroblast feeder-cells may be a pollutant. In the present study, human skin fibroblasts (HSFs) were successfully harvested from patients with burns and patient-specific iPSCs were generated using a non-integration method with a feeder-free approach. The octamer-binding transcription factor 4 (OCT4), sex-determining region Y box 2 (SOX2) and NANOG transcription factors were delivered using Sendai virus vectors. iPSCs exhibited representative human embryonic stem cell-like morphology and proliferation characteristics. They also expressed pluripotent markers, including OCT4, NANOG, SOX2, TRA181, stage-specific embryonic antigen 4 and TRA-160, and exhibited a normal karyotype. Teratoma and embryoid body formation revealed that iPSCs were able to differentiate into cells of all three germ layers in vitro and in vivo. The results of the present study demonstrate that HSFs derived from patients with burns, may be reprogrammed into stem cells with pluripotency, which provides a basis for cell‑based skin tissue engineering in the future.

The effect of a rehabilitation nursing intervention model on improving the comprehensive health status of patients with hand burns.

PubMed

Li, Lin; Dai, Jia-Xi; Xu, Le; Huang, Zhen-Xia; Pan, Qiong; Zhang, Xi; Jiang, Mei-Yun; Chen, Zhao-Hong

2017-06-01

To observe the effect of a rehabilitation intervention on the comprehensive health status of patients with hand burns. Most studies of hand-burn patients have focused on functional recovery. There have been no studies involving a biological-psychological-social rehabilitation model of hand-burn patients. A randomized controlled design was used. Patients with hand burns were recruited to the study, and sixty patients participated. Participants were separated into two groups: (1) The rehabilitation intervention model group (n=30) completed the rehabilitation intervention model, which included the following measures: enhanced social support, intensive health education, comprehensive psychological intervention, and graded exercise. (2) The control group (n=30) completed routine treatment. Intervention lasted 5 weeks. Analysis of variance (ANOVA) and Student's t test were conducted. The rehabilitation intervention group had significantly better scores than the control group for comprehensive health, physical function, psychological function, social function, and general health. The differences between the index scores of the two groups were statistically significant. The rehabilitation intervention improved the comprehensive health status of patients with hand burns and has favorable clinical application. The comprehensive rehabilitation intervention model used here provides scientific guidance for medical staff aiming to improve the integrated health status of hand-burn patients and accelerate their recovery. What does this paper contribute to the wider global clinical community? Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Aspects of Cool-Flame Supported Droplet Combustion in Microgravity

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Dietrich, Daniel L.; Williams, Forman A.

2015-01-01

Droplet combustion experiments performed on board the International Space Station have shown that normal-alkane fuels with negative temperature coefficient (NTC) chemistry can support quasi-steady, low-temperature combustion without any visible flame. Here we review the results for n-decane, n-heptane, and n-octane droplets burning in carbon dioxidehelium diluted environments at different pressures and initial droplet sizes. Experimental results for cool-flame burning rates, flame standoff ratios, and extinction diameters are compared against simplified theoretical models of the phenomenon. A simplified quasi-steady model based on the partial-burning regime of Lin predicts the burning rate, and flame standoff ratio reasonably well for all three normal alkanes. The second-stage cool-flame burning and extinction following the first-stage hot-flame combustion, however, shows a small dependence on the initial droplet size, thus deviating from the quasi-steady results. An asymptotic model that estimates the oxygen depletion by the hot flame and its influence on cool-flame burning rates is shown to correct the quasi-steady results and provide a better comparison with the measured burning-rate results.This work was supported by the NASA Space Life and Physical Sciences Research and Applications Program and the International Space Station Program.

Global emissions of trace gases, particulate matter, and hazardous air pollutants from open burning of domestic waste.

PubMed

Wiedinmyer, Christine; Yokelson, Robert J; Gullett, Brian K

2014-08-19

The open burning of waste, whether at individual residences, businesses, or dump sites, is a large source of air pollutants. These emissions, however, are not included in many current emission inventories used for chemistry and climate modeling applications. This paper presents the first comprehensive and consistent estimates of the global emissions of greenhouse gases, particulate matter, reactive trace gases, and toxic compounds from open waste burning. Global emissions of CO2 from open waste burning are relatively small compared to total anthropogenic CO2; however, regional CO2 emissions, particularly in many developing countries in Asia and Africa, are substantial. Further, emissions of reactive trace gases and particulate matter from open waste burning are more significant on regional scales. For example, the emissions of PM10 from open domestic waste burning in China is equivalent to 22% of China's total reported anthropogenic PM10 emissions. The results of the emissions model presented here suggest that emissions of many air pollutants are significantly underestimated in current inventories because open waste burning is not included, consistent with studies that compare model results with available observations.

Valproic acid treatment attenuates caspase-3 activation and improves survival after lethal burn injury in a rodent model.

PubMed

Luo, Hong-Min; Hu, Sen; Bai, Hui-Ying; Wang, Hai-Bin; Du, Ming-Hua; Lin, Zhi-Long; Ma, Li; Wang, Huan; Lv, Yi; Sheng, Zhi-Yong

2014-01-01

Burn injury may result in multiple organ dysfunction partially because of apoptotic cell death. The authors have previously shown that valproic acid (VPA) improves survival in a dog burn model. The aim of this study is to examine whether a VPA improves survival in a rodent burn model and whether this was because of inhibition of cell apoptosis. Rats were subjected to third-degree 55% TBSA burns and randomized to treatment with a VPA (300 mg/kg) or normal saline. One group of animals was monitored for 12 hours for survival analysis; another group was killed at 6 hours after injury, and brains, hearts, and blood samples were harvested for examination. Plasma creatine kinase (CK)-MB activities and neuron-specific enolase (NSE) levels were measured to evaluate the cardiac and brain damages. The effects of a VPA on acetylation of histone H3 and caspase-3 activation were also evaluated. Major burn injury resulted in a significant decrease in the acetylation of histone H3, and there was an increase in plasma CK-MB activities, NSE concentrations, and tissue levels of activated caspase-3. A VPA treatment significantly increased the acetylation of histone H3 and survival of the animals after major burn injury. In addition, a VPA treatment significantly attenuated the plasma CK-MB activities, an NSE concentrations, and inhibited caspase-3 activation after major burn injury. These results indicate that a VPA can attenuate cardiac and brain injury, and can improve survival in a rodent model of lethal burn injury. These protective effects may be mediated in part through the inhibition of caspase-3 activation.

Wound healing effects of deoxyshikonin isolated from Jawoongo: In vitro and in vivo studies.

PubMed

Park, Jun Yeon; Kwak, Jin Ho; Kang, Ki Sung; Jung, Eun Bee; Lee, Dong-Soo; Lee, Sanghyun; Jung, Yujung; Kim, Ki Hyun; Hwang, Gwi Seo; Lee, Hye Lim; Yamabe, Noriko; Kim, Su-Nam

2017-03-06

Jawoongo is a traditional drug ointment (with a traditional botanic formula) used for the treatment of burns and wounds in Korea. One of the components of Jawoongo is Lithospermi Radix (LR, the dried root of Lithospermum erythrorhizon Siebold & Zucc., also known as Zicao or Gromwell), which contains deoxyshikonin and its derivatives. The aim of the present study was to investigate the effects of deoxyshikonin on wound healing. The effects of LR extract and deoxyshikonin on tube formation and migration were measured in human umbilical vein vascular endothelial cells (HUVEC) and HaCaT cells, respectively. We evaluated protein expression of mitogen-activated protein kinase (MAPK) activation by Western blotting. The wound healing effects of deoxyshikonin was assessed in a mouse model of cutaneous wounds. The results showed that deoxyshikonin enhanced tube formation in HUVEC and migration in HaCaT cells. From the western blot analysis, we found that deoxyshikonin stimulated the phosphorylation of p38 and extracellular signal-regulated kinase (ERK) in HaCaT cells. Moreover, 20µm deoxyshikonin-treated groups showed accelerated wound closure compared with the controls in a mouse model of cutaneous wounds. In conclusion, the current data indicate that deoxyshikonin treatment elevated tube formation in HUVECs, and that deoxyshikonin-induced proliferation and migration in HaCaT cells were mediated by the activation of ERK and p38 MAPKs, respectively. Collectively, these data suggest that deoxyshikonin in Jawoongo must be an active compound for may be wound healing. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Improving Long-term Post-wildfire hydrologic simulations using ParFlow

NASA Astrophysics Data System (ADS)

Lopez, S. R.; Kinoshita, A. M.

2015-12-01

Wildfires alter the natural hydrologic processes within a watershed. After vegetation is burned, the combustion of organic material and debris settles into the soil creating a hydrophobic layer beneath the soil surface with varying degree of thickness and depth. Vegetation regrowth rates vary as a function of radiative exposure, burn severity, and precipitation patterns. Hydrologic models used by the Burned Area Emergency Response (BAER) teams use input data and model calibration constraints that are generally either one-dimensional, empirically-based models, or two-dimensional, conceptually-based models with lumped parameter distributions. These models estimate runoff measurements at the watershed outlet; however, do not provide a distributed hydrologic simulation at each point within the watershed. This work uses ParFlow, a three-dimensional, distributed hydrologic model to (1) correlate burn severity with hydrophobicity, (2) evaluate vegetation recovery rate on water components, and (3) improve flood prediction for managers to help with resource allocation and management operations in burned watersheds. ParFlow is applied to Devil Canyon (43 km2) in San Bernardino, California, which was 97% burned in the 2003 Old Fire. The model set-up uses a 30m-cell size resolution over a 6.7 km by 6.4 km lateral extent. The subsurface reaches 30 m and is assigned a variable cell thickness. Variable subsurface thickness allows users to explicitly consider the degree of recovery throughout the stages of regrowth. Burn severity maps from remotely sensed imagery are used to assign initial hydrophobic layer parameters and thickness. Vegetation regrowth is represented with satellite an Enhanced Vegetation Index. Pre and post-fire hydrologic response is evaluated using runoff measurements at the watershed outlet, and using water component (overland flow, lateral flow, baseflow) measurements.

Finding mouse models of human lymphomas and leukemia's using the Jackson laboratory mouse tumor biology database.

PubMed

Begley, Dale A; Sundberg, John P; Krupke, Debra M; Neuhauser, Steven B; Bult, Carol J; Eppig, Janan T; Morse, Herbert C; Ward, Jerrold M

2015-12-01

Many mouse models have been created to study hematopoietic cancer types. There are over thirty hematopoietic tumor types and subtypes, both human and mouse, with various origins, characteristics and clinical prognoses. Determining the specific type of hematopoietic lesion produced in a mouse model and identifying mouse models that correspond to the human subtypes of these lesions has been a continuing challenge for the scientific community. The Mouse Tumor Biology Database (MTB; http://tumor.informatics.jax.org) is designed to facilitate use of mouse models of human cancer by providing detailed histopathologic and molecular information on lymphoma subtypes, including expertly annotated, on line, whole slide scans, and providing a repository for storing information on and querying these data for specific lymphoma models. Copyright © 2015 Elsevier Inc. All rights reserved.

Determination of deuterium–tritium critical burn-up parameter by four temperature theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nazirzadeh, M.; Ghasemizad, A.; Khanbabei, B.

Conditions for thermonuclear burn-up of an equimolar mixture of deuterium-tritium in non-equilibrium plasma have been investigated by four temperature theory. The photon distribution shape significantly affects the nature of thermonuclear burn. In three temperature model, the photon distribution is Planckian but in four temperature theory the photon distribution has a pure Planck form below a certain cut-off energy and then for photon energy above this cut-off energy makes a transition to Bose-Einstein distribution with a finite chemical potential. The objective was to develop four temperature theory in a plasma to calculate the critical burn up parameter which depends upon initialmore » density, the plasma components initial temperatures, and hot spot size. All the obtained results from four temperature theory model are compared with 3 temperature model. It is shown that the values of critical burn-up parameter calculated by four temperature theory are smaller than those of three temperature model.« less

Burning rates of wood cribs with implications for wildland fires

Treesearch

Sara McAllister; Mark Finney

2016-01-01

Wood cribs are often used as ignition sources for room fire tests and the well characterized burning rates may also have applications to wildland fires. The burning rate of wildland fuel structures, whether the needle layer on the ground or trees and shrubs themselves, is not addressed in any operational fire model and no simple model exists. Several relations...

Challenges of assessing fire and burn severity using field measures, remote sensing and modelling

Treesearch

Penelope Morgan; Robert E. Keane; Gregory K. Dillon; Theresa B. Jain; Andrew T. Hudak; Eva C. Karau; Pamela G. Sikkink; Zachery A. Holden; Eva K. Strand

2014-01-01

Comprehensive assessment of ecological change after fires have burned forests and rangelands is important if we are to understand, predict and measure fire effects. We highlight the challenges in effective assessment of fire and burn severity in the field and using both remote sensing and simulation models. We draw on diverse recent research for guidance on assessing...

Mouse models rarely mimic the transcriptome of human neurodegenerative diseases: A systematic bioinformatics-based critique of preclinical models.

PubMed

Burns, Terry C; Li, Matthew D; Mehta, Swapnil; Awad, Ahmed J; Morgan, Alexander A

2015-07-15

Translational research for neurodegenerative disease depends intimately upon animal models. Unfortunately, promising therapies developed using mouse models mostly fail in clinical trials, highlighting uncertainty about how well mouse models mimic human neurodegenerative disease at the molecular level. We compared the transcriptional signature of neurodegeneration in mouse models of Alzheimer׳s disease (AD), Parkinson׳s disease (PD), Huntington׳s disease (HD) and amyotrophic lateral sclerosis (ALS) to human disease. In contrast to aging, which demonstrated a conserved transcriptome between humans and mice, only 3 of 19 animal models showed significant enrichment for gene sets comprising the most dysregulated up- and down-regulated human genes. Spearman׳s correlation analysis revealed even healthy human aging to be more closely related to human neurodegeneration than any mouse model of AD, PD, ALS or HD. Remarkably, mouse models frequently upregulated stress response genes that were consistently downregulated in human diseases. Among potential alternate models of neurodegeneration, mouse prion disease outperformed all other disease-specific models. Even among the best available animal models, conserved differences between mouse and human transcriptomes were found across multiple animal model versus human disease comparisons, surprisingly, even including aging. Relative to mouse models, mouse disease signatures demonstrated consistent trends toward preserved mitochondrial function protein catabolism, DNA repair responses, and chromatin maintenance. These findings suggest a more complex and multifactorial pathophysiology in human neurodegeneration than is captured through standard animal models, and suggest that even among conserved physiological processes such as aging, mice are less prone to exhibit neurodegeneration-like changes. This work may help explain the poor track record of mouse-based translational therapies for neurodegeneration and provides a path forward to critically evaluate and improve animal models of human disease. Copyright © 2015 Elsevier B.V. All rights reserved.

Climate versus carbon dioxide controls on biomass burning: a model analysis of the glacial-interglacial contrast

NASA Astrophysics Data System (ADS)

Calvo, M. Martin; Prentice, I. C.; Harrison, S. P.

2014-11-01

Climate controls fire regimes through its influence on the amount and types of fuel present and their dryness. CO2 concentration constrains primary production by limiting photosynthetic activity in plants. However, although fuel accumulation depends on biomass production, and hence on CO2 concentration, the quantitative relationship between atmospheric CO2 concentration and biomass burning is not well understood. Here a fire-enabled dynamic global vegetation model (the Land surface Processes and eXchanges model, LPX) is used to attribute glacial-interglacial changes in biomass burning to an increase in CO2, which would be expected to increase primary production and therefore fuel loads even in the absence of climate change, vs. climate change effects. Four general circulation models provided last glacial maximum (LGM) climate anomalies - that is, differences from the pre-industrial (PI) control climate - from the Palaeoclimate Modelling Intercomparison Project Phase~2, allowing the construction of four scenarios for LGM climate. Modelled carbon fluxes from biomass burning were corrected for the model's observed prediction biases in contemporary regional average values for biomes. With LGM climate and low CO2 (185 ppm) effects included, the modelled global flux at the LGM was in the range of 1.0-1.4 Pg C year-1, about a third less than that modelled for PI time. LGM climate with pre-industrial CO2 (280 ppm) yielded unrealistic results, with global biomass burning fluxes similar to or even greater than in the pre-industrial climate. It is inferred that a substantial part of the increase in biomass burning after the LGM must be attributed to the effect of increasing CO2 concentration on primary production and fuel load. Today, by analogy, both rising CO2 and global warming must be considered as risk factors for increasing biomass burning. Both effects need to be included in models to project future fire risks.

Long term mortality in critically ill burn survivors.

PubMed

Nitzschke, Stephanie; Offodile, Anaeze C; Cauley, Ryan P; Frankel, Jason E; Beam, Andrew; Elias, Kevin M; Gibbons, Fiona K; Salim, Ali; Christopher, Kenneth B

2017-09-01

Little is known about long term survival risk factors in critically ill burn patients who survive hospitalization. We hypothesized that patients with major burns who survive hospitalization would have favorable long term outcomes. We performed a two center observational cohort study in 365 critically ill adult burn patients who survived to hospital discharge. The exposure of interest was major burn defined a priori as >20% total body surface area burned [TBSA]. The modified Baux score was determined by age + %TBSA+ 17(inhalational injury). The primary outcome was all-cause 5year mortality based on the US Social Security Administration Death Master File. Adjusted associations were estimated through fitting of multivariable logistic regression models. Our final model included adjustment for inhalational injury, presence of 3rd degree burn, gender and the acute organ failure score, a validated ICU risk-prediction score derived from age, ethnicity, surgery vs. medical patient type, comorbidity, sepsis and acute organ failure covariates. Time-to-event analysis was performed using Cox proportional hazard regression. Of the cohort patients studied, 76% were male, 29% were non white, 14% were over 65, 32% had TBSA >20%, and 45% had inhalational injury. The mean age was 45, 92% had 2nd degree burns, 60% had 3rd degree burns, 21% received vasopressors, and 26% had sepsis. The mean TBSA was 20.1%. The mean modified Baux score was 72.8. Post hospital discharge 5year mortality rate was 9.0%. The 30day hospital readmission rate was 4%. Patients with major burns were significantly younger (41 vs. 47 years) had a significantly higher modified Baux score (89 vs. 62), and had significantly higher comorbidity, acute organ failure, inhalational injury and sepsis (all P<0.05). There were no differences in gender and the acute organ failure score between major and non-major burns. In the multivariable logistic regression model, major burn was associated with a 3 fold decreased odds of 5year post-discharge mortality compared to patients with TBSA<20% [OR=0.29 (95%CI 0.11-0.78; P=0.014)]. The adjusted model showed good discrimination [AUC 0.81 (95%CI 0.74-0.89)] and calibration (Hosmer-Lemeshow χ 2 P=0.67). Cox proportional hazard multivariable regression modeling, adjusting for inhalational injury, presence of 3rd degree burn, gender and the acute organ failure score, showed that major burn was predictive of lower mortality following hospital admission [HR=0.34 (95% CI 0.15-0.76; P=0.009)]. The modified Baux score was not predictive for mortality following hospital discharge [OR 5year post-discharge mortality=1.00 (95%CI 0.99-1.02; P=0.74); HR for post-discharge mortality=1.00 (95% CI 0.99-1.02; P=0.55)]. Critically ill patients with major burns who survive to hospital discharge have decreased 5year mortality compared to those with less severe burns. ICU Burn unit patients who survive to hospital discharge are younger with less comorbidities. The observed relationship is likely due to the relatively higher physiological reserve present in those who survive a Burn ICU course which may provide for a survival advantage during recovery after major burn. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Spatially-varied erosion modeling using WEPP for timber harvested and burned hillslopes

Treesearch

Peter R. Robichaud; T. M. Monroe

1997-01-01

Spatially-varied hydrologic surface conditions exist on steep hillslopes after timber harvest operation and site preparation burning treatments. Site preparation burning creates low- and high-severity burn surface conditions or disturbances. In this study, a hillslope was divided into multiple combinations of surface conditions to determine how their spatial...

Prior stress exposure increases pain behaviors in a rat model of full thickness thermal injury.

PubMed

Nyland, Jennifer E; McLean, Samuel A; Averitt, Dayna L

2015-12-01

Thermal burns among individuals working in highly stressful environments, such as firefighters and military Service Members, are common. Evidence suggests that pre-injury stress may exaggerate pain following thermal injury; however current animal models of burn have not evaluated the potential influence of pre-burn stress. This sham-controlled study evaluated the influence of prior stress exposure on post-burn thermal and mechanical sensitivity in male Sprague-Dawley rats. Rats were exposed to 20 min of inescapable swim stress or sham stress once per day for three days. Exposure to inescapable swim stress (1) increased the intensity and duration of thermal hyperalgesia after subsequent burn and (2) accelerated the onset of thermal hyperalgesia and mechanical allodynia after subsequent burn. This stress-induced exacerbation of pain sensitivity was reversed by pretreatment and concurrent treatment with the serotonin-norepinephrine reuptake inhibitor (SNRI) duloxetine. These data suggest a better understanding of mechanisms by which prior stress augments pain after thermal burn may lead to improved pain treatments for burn survivors. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

The American Burn Association/Shriners Hospitals for Children Burn Outcomes Program: a progress report at 15 years.

PubMed

Tompkins, Ronald G; Liang, Matthew H; Lee, Austin F; Kazis, Lewis E

2012-09-01

The American Burn Association and the Shriners Hospitals for Children Outcomes Program has been in development for more than 15 years. Many of the tools and important findings are described in this special issue of The Journal of Trauma. This unique program in outcomes research introduces a model for outcome assessments from the patient-centered perspective with a cohort of 1,140 children with burn injury after hospitalization for up to 4 years. The findings represent a fundamental contribution to the field of burn care for monitoring outcomes from the perspective of the parent or child/adolescent. The Multi-Center Benchmarking Study of four burn centers serve as a model for collecting empiric scientific data on the variation and the expected trajectories of recovery in the most important domains of patient outcomes and can inform clinical decisions and the conduct of health service research. The dramatic progress in survival of children with severe burn injury and other advances in burn management can now move into a new phase of understanding the most cost-effective components of this care.

Thermal characteristics of amphibian microhabitats in a fire-disturbed landscape

USGS Publications Warehouse

Hossack, B.R.; Eby, L.A.; Guscio, C.G.; Corn, P.S.

2009-01-01

Disturbance has long been a central issue in amphibian conservation, often regarding negative effects of logging or other forest management activities, but some amphibians seem to prefer disturbed habitats. After documenting increased use of recently burned forests by boreal toads (Bufo boreas), we hypothesized that burned habitats provided improved thermal opportunities in terrestrial habitats. We tested this hypothesis by conducting a radio telemetry study of habitat use (reported previously) and by using physical models that simulated the temperature of adult toads. We deployed 108 physical models in and adjacent to a 1-year old burn using a fully-replicated design with three burn severities (unburned, partial, high severity) and four microhabitats (open surface, under vegetation, under log, in burrow). Model temperatures were compared to a range of preferred temperatures in published studies. We found 70% more observations within the preferred temperature range of B. boreas in forests burned with high severity than in unburned areas. Burned forest was warmer than unburned forest across all microhabitats, but the largest relative difference was in burrows, which averaged 3 ??C warmer in high-severity burn areas and remained warmer though the night. More than twice as many observations were within the preferred temperature range in high-severity burrows than in unburned burrows. Areas burned with high severity were still warmer than unburned forest 3 years after the fire. Habitat use of toads during the concurrent radio telemetry study matched that predicted by the physical models. These results suggest there are fitness-linked benefits to toads using burned habitats, such as increased growth, fertility, and possibly disease resistance. However, increased soil temperatures that result from wildfire may be detrimental to other amphibian species that prefer cooler temperatures and stable environments. More broadly, our data illustrate the use of physical models to measure and interpret changes that amphibians may experience from disturbance, and highlight the need for research linking vital rates such as growth and survival to disturbance.

Numerical and experimental study of thermal explosions in LX-10 and PBX 9501: Influence of thermal damage on deflagration processes

NASA Astrophysics Data System (ADS)

Tringe, J. W.; Kercher, J. R.; Springer, H. K.; Glascoe, E. A.; Levie, H. W.; Hsu, P.; Willey, T. M.; Molitoris, J. D.

2013-07-01

We employ in-situ flash x-ray imaging, together with a detailed multiphase convective burn model, to demonstrate how explosives' binder characteristics influence the burning processes in thermal explosions. Our study focuses on the HMX-based explosives LX-10 and PBX 9501. While the HMX (cyclotetramethylene-tetranitramine) crystallite size distributions for these two explosives are nearly identical before heating, our experiments and simulations indicate that after heating, variations result due to differences in binder composition. Post-ignition flash x-ray images reveal that the average density decreases at late times more rapidly in PBX 9501 than LX-10, suggesting a faster conductive burning rate in PBX-9501. Heated permeability measurements in LX-10 and PBX 9501 demonstrate that the binder system characteristics influence the evolution of connected porosity. Once ignited, connected porosity provides pathways for product gas heating ahead of the reaction front and additional surface area for burning, facilitating the transition from conductive to convective burning modes. A multiphase convective burn model implemented in the ALE3D code is used to better understand the influence on burn rates of material properties such as porosity and effective thermally damaged particle size. In this context, particles are defined as gas-impermeable binder-coated crystallites and agglomerations with a set of effective radii reff. Model results demonstrate quantitative agreement with containment wall velocity for confined PBX 9501 and LX-10, and qualitative agreement with density as a function of position in the burning explosive. The model predicts a decrease in post-ignition containment wall velocity with larger radii in reff. These experimental data and model results together provide insight into the initiation and propagation of the reaction wave that defines the convective burn front in HMX-based explosives, a necessary step toward predicting violence under a broad range of conditions.

EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT

PubMed Central

Li, Hua-Liang; Deng, Yi-Tao; Zhang, Zi-Ran; Fu, Qi-Rui; Zheng, Ya-Hui; Cao, Xing-Mei; Nie, Jing; Fu, Li-Wen; Chen, Li-Ping; Xiong, You-Xiong; Shen, Dong-Yan; Chen, Qing-Xi

2017-01-01

Background: Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. Materials and methods: The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment - (1% wt/wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. Results: COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) (P<0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). Conclusions: COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns. Abbreviations: COBO, crocodile oil burn ointment; SSD, silver sulfadiazine; MEBO, moist exposed burn ointment; TCM, traditional Chinese medicine; CHM, Chinese herbal medicine; GC-MS, gas chromatography-mass spectrometry. PMID:28480384

EVALUATION OF EFFECTIVENESS IN A NOVEL WOUND HEALING OINTMENT-CROCODILE OIL BURN OINTMENT.

PubMed

Li, Hua-Liang; Deng, Yi-Tao; Zhang, Zi-Ran; Fu, Qi-Rui; Zheng, Ya-Hui; Cao, Xing-Mei; Nie, Jing; Fu, Li-Wen; Chen, Li-Ping; Xiong, You-Xiong; Shen, Dong-Yan; Chen, Qing-Xi

2017-01-01

Crocodile oil and its products are used as ointments for burns and scalds in traditional medicines. A new ointment formulation - crocodile oil burn ointment (COBO) was developed to provide more efficient wound healing activity. The purpose of the study was to evaluate the burn healing efficacy of this new formulation by employing deep second-degree burns in a Wistar rat model. The analgesic and anti-inflammatory activities of COBO were also studied to provide some evidences for its further use. The wound healing potential of this formulation was evaluated by employing a deep second-degree burn rat model and the efficiency was comparatively assessed against a reference ointment - (1% wt/wt) silver sulfadiazine (SSD). After 28 days, the animals were euthanized and the wounds were removed for transversal and longitudinal histological studies. Acetic acid-induced writhing in mice was used to evaluate the analgesic activity and its anti-inflammatory activity was observed in xylene -induced edema in mice. COBO enhanced the burn wound healing (20.5±1.3 d) as indicated by significant decrease in wound closure time compared with the burn control (25.0±2.16 d) ( P <0.01). Hair follicles played an importance role in the physiological functions of the skin, and their growth in the wound could be revealed for the skin regeneration situation. Histological results showed that the hair follicles were well-distributed in the post-burn skin of COBO treatment group, and the amounts of total, active, primary and secondary hair follicles in post-burn 28-day skin of COBO treatment groups were more than those in burn control and SSD groups. On the other hand, the analgesic and anti-inflammatory activity of COBO were much better than those of control group, while they were very close to those of moist exposed burn ointment (MEBO). COBO accelerated wound closure, reduced inflammation, and had analgesic effects compared with SSD in deep second degree rat burn model. These findings suggest that COBO would be a potential therapy for treating human burns. Abbreviations: COBO, crocodile oil burn ointment; SSD, silver sulfadiazine; MEBO, moist exposed burn ointment; TCM, traditional Chinese medicine; CHM, Chinese herbal medicine; GC-MS, gas chromatography-mass spectrometry.

Potential Use of Dimethyl Sulfoxide in Treatment of Infections Caused by Pseudomonas aeruginosa

PubMed Central

Guo, Qiao; Wu, Qiaolian; Bai, Dangdang; Liu, Yang; Chen, Lin; Jin, Sheng; Wu, Yuting

2016-01-01

Dimethyl sulfoxide (DMSO) is commonly used as a solvent to dissolve water-insoluble drugs or other test samples in both in vivo and in vitro experiments. It was observed during our experiment that DMSO at noninhibitory concentrations could significantly inhibit pyocyanin production in the human pathogen Pseudomonas aeruginosa. Pyocyanin is an important pathogenic factor whose production is controlled by a cell density-dependent quorum-sensing (QS) system. Investigation of the effect of DMSO on QS showed that DMSO has significant QS antagonistic activities and concentrations of DMSO in the micromolar range attenuated a battery of QS-controlled virulence factors, including rhamnolipid, elastase, and LasA protease production and biofilm formation. Further study indicated that DMSO inhibition of biofilm formation and pyocyanin production was attained by reducing the level of production of an autoinducer molecule of the rhl QS system, N-butanoyl-l-homoserine lactone (C4-HSL). In a mouse model of a burn wound infection with P. aeruginosa, treatment with DMSO significantly decreased mouse mortality compared with that for mice in the control group. The capacity of DMSO to attenuate the pathogenicity of P. aeruginosa points to the potential use of DMSO as an antipathogenic agent for the treatment of P. aeruginosa infection. As a commonly used solvent, however, DMSO's impact on bacterial virulence calls for cautionary attention in its usage in biological, medicinal, and clinical studies. PMID:27645245

Effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit.

PubMed

Xi, Peng; Li, Yan; Ge, Xiaojin; Liu, Dandan; Miao, Mingsan

2018-05-01

Observing the effect of nano-silver hydrogel coating film on deep partial thickness scald model of rabbit. We prepared boiling water scalded rabbits with deep II degree scald models and applied high, medium and low doses of nano-silver hydrogel coating film for different time and area. Then we compared the difference of burned paper weight before administration and after administration model burns, burn local skin irritation points infection, skin crusting and scabs from the time, and the impact of local skin tissue morphology. Rabbits deep II degree burn model successful modeling; on day 12, 18, high, medium and low doses of nano-silver hydrogel coating film significantly reduced skin irritation of rabbits infected with the integral value ( P  < 0.01, P  < 0.05); high, medium and low doses of nano-silver hydrogel coating film group significantly decreased skin irritation, infection integral value ( P  < 0.01, P  < 0.05); high, medium and low doses of nano-silver hydrogel coating film significantly reduced film rabbits' scalded skin crusting time ( P  < 0.01), significantly shortened the rabbit skin burns from the scab time ( P  < 0.01), and significantly improved the treatment of skin diseases in rabbits scald model change ( P  < 0.01, P  < 0.05). The nano-silver hydrogel coating film on the deep partial thickness burns has a significant therapeutic effect; external use has a significant role in wound healing.

A systematic review of advance practice providers in acute care: options for a new model in a burn intensive care unit.

PubMed

Edkins, Renee E; Cairns, Bruce A; Hultman, C Scott

2014-03-01

Accreditation Council for Graduate Medical Education mandated work-hour restrictions have negatively impacted many areas of clinical care, including management of burn patients, who require intensive monitoring, resuscitation, and procedural interventions. As surgery residents become less available to meet service needs, new models integrating advanced practice providers (APPs) into the burn team must emerge. We performed a systematic review of APPs in critical care questioning, how best to use all providers to solve these workforce challenges? We performed a systematic review of PubMed, CINAHL, Ovid, and Google Scholar, from 2002 to 2012, using the key words: nurse practitioner, physician assistant, critical care, and burn care. After applying inclusion/exclusion criteria, 18 relevant articles were selected for review. In addition, throughput and financial models were developed to examine provider staffing patterns. Advanced practice providers in critical care settings function in various models, both with and without residents, reporting to either an intensivist or an attending physician. When APPs participated, patient outcomes were similar or improved compared across provider models. Several studies reported considerable cost-savings due to decrease length of stay, decreased ventilator days, and fewer urinary tract infections when nurse practitioners were included in the provider mix. Restrictions in resident work-hours and changing health care environments require that new provider models be created for acute burn care. This article reviews current utilization of APPs in critical care units and proposes a new provider model for burn centers.

Burn injury models of care: A review of quality and cultural safety for care of Indigenous children.

PubMed

Fraser, Sarah; Grant, Julian; Mackean, Tamara; Hunter, Kate; Holland, Andrew J A; Clapham, Kathleen; Teague, Warwick J; Ivers, Rebecca Q

2018-05-01

Safety and quality in the systematic management of burn care is important to ensure optimal outcomes. It is not clear if or how burn injury models of care uphold these qualities, or if they provide a space for culturally safe healthcare for Indigenous peoples, especially for children. This review is a critique of publically available models of care analysing their ability to facilitate safe, high-quality burn care for Indigenous children. Models of care were identified and mapped against cultural safety principles in healthcare, and against the National Health and Medical Research Council standard for clinical practice guidelines. An initial search and appraisal of tools was conducted to assess suitability of the tools in providing a mechanism to address quality and cultural safety. From the 53 documents found, 6 were eligible for review. Aspects of cultural safety were addressed in the models, but not explicitly, and were recorded very differently across all models. There was also limited or no cultural consultation documented in the models of care reviewed. Quality in the documents against National Health and Medical Research Council guidelines was evident; however, description or application of quality measures was inconsistent and incomplete. Gaps concerning safety and quality in the documented care pathways for Indigenous peoples' who sustain a burn injury and require burn care highlight the need for investigation and reform of current practices. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Multispectral imaging burn wound tissue classification system: a comparison of test accuracies between several common machine learning algorithms

NASA Astrophysics Data System (ADS)

Squiers, John J.; Li, Weizhi; King, Darlene R.; Mo, Weirong; Zhang, Xu; Lu, Yang; Sellke, Eric W.; Fan, Wensheng; DiMaio, J. Michael; Thatcher, Jeffrey E.

2016-03-01

The clinical judgment of expert burn surgeons is currently the standard on which diagnostic and therapeutic decisionmaking regarding burn injuries is based. Multispectral imaging (MSI) has the potential to increase the accuracy of burn depth assessment and the intraoperative identification of viable wound bed during surgical debridement of burn injuries. A highly accurate classification model must be developed using machine-learning techniques in order to translate MSI data into clinically-relevant information. An animal burn model was developed to build an MSI training database and to study the burn tissue classification ability of several models trained via common machine-learning algorithms. The algorithms tested, from least to most complex, were: K-nearest neighbors (KNN), decision tree (DT), linear discriminant analysis (LDA), weighted linear discriminant analysis (W-LDA), quadratic discriminant analysis (QDA), ensemble linear discriminant analysis (EN-LDA), ensemble K-nearest neighbors (EN-KNN), and ensemble decision tree (EN-DT). After the ground-truth database of six tissue types (healthy skin, wound bed, blood, hyperemia, partial injury, full injury) was generated by histopathological analysis, we used 10-fold cross validation to compare the algorithms' performances based on their accuracies in classifying data against the ground truth, and each algorithm was tested 100 times. The mean test accuracy of the algorithms were KNN 68.3%, DT 61.5%, LDA 70.5%, W-LDA 68.1%, QDA 68.9%, EN-LDA 56.8%, EN-KNN 49.7%, and EN-DT 36.5%. LDA had the highest test accuracy, reflecting the bias-variance tradeoff over the range of complexities inherent to the algorithms tested. Several algorithms were able to match the current standard in burn tissue classification, the clinical judgment of expert burn surgeons. These results will guide further development of an MSI burn tissue classification system. Given that there are few surgeons and facilities specializing in burn care, this technology may improve the standard of burn care for patients without access to specialized facilities.

A Model to Improve Detection of Nonaccidental Pediatric Burns.

PubMed

Nigro, Lauren C; Feldman, Michael J; Foster, Robin L; Pozez, Andrea L

2018-06-01

Pediatric burn patients warrant thorough evaluation because a sizeable proportion of pediatric burns are nonaccidental. A multidisciplinary method involving an internal child protection team (CPT) was developed and used to identify suspected nonaccidental pediatric burns in all pediatric burn patients 5 years of age or younger who were evaluated by the CPT and social workers at our institution over a 55-month period. We identified 343 cases for review that fit our age criteria, 6 of which we identified as cases of suspected abuse or neglect. On average, these patients were younger, suffered greater total body surface area burns (TBSA), and required a longer length of stay in the hospital than the total population. We have not had readmissions for repeat nonaccidental pediatric burn injuries in this group of patients since this model was implemented. Our multidisciplinary method might provide a more consistent and reliable method for identifying cases of suspected abuse. © 2018 American Medical Association. All Rights Reserved.

X-Ray Fluorescence to Estimate the Maximum Temperature Reached at Soil Surface during Experimental Slash-and-Burn Fires.

PubMed

Melquiades, Fábio L; Thomaz, Edivaldo L

2016-05-01

An important aspect for the evaluation of fire effects in slash-and-burn agricultural system, as well as in wildfire, is the soil burn severity. The objective of this study is to estimate the maximum temperature reached in real soil burn events using energy dispersive X-ray fluorescence (EDXRF) as an analytical tool, combined with partial least square (PLS) regression. Muffle-heated soil samples were used for PLS regression model calibration and two real slash-and-burn soils were tested as external samples in the model. It was possible to associate EDXRF spectra alterations to the maximum temperature reached in the heat affected soils with about 17% relative standard deviation. The results are promising since the analysis is fast, nondestructive, and conducted after the burn event, although local calibration for each type of burned soil is necessary. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Assessing the response of area burned to changing climate in western boreal North America using a Multivariate Adaptive Regression Splines (MARS) approach

USGS Publications Warehouse

Balshi, M. S.; McGuire, A.D.; Duffy, P.; Flannigan, M.; Walsh, J.; Melillo, J.

2009-01-01

Fire is a common disturbance in the North American boreal forest that influences ecosystem structure and function. The temporal and spatial dynamics of fire are likely to be altered as climate continues to change. In this study, we ask the question: how will area burned in boreal North America by wildfire respond to future changes in climate? To evaluate this question, we developed temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5?? (latitude ?? longitude) resolution using a Multivariate Adaptive Regression Spline (MARS) approach across Alaska and Canada. Burned area was substantially more predictable in the western portion of boreal North America than in eastern Canada. Burned area was also not very predictable in areas of substantial topographic relief and in areas along the transition between boreal forest and tundra. At the scale of Alaska and western Canada, the empirical fire models explain on the order of 82% of the variation in annual area burned for the period 1960-2002. July temperature was the most frequently occurring predictor across all models, but the fuel moisture codes for the months June through August (as a group) entered the models as the most important predictors of annual area burned. To predict changes in the temporal and spatial dynamics of fire under future climate, the empirical fire models used output from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through the year 2100 across Alaska and western Canada. Relative to 1991-2000, the results suggest that average area burned per decade will double by 2041-2050 and will increase on the order of 3.5-5.5 times by the last decade of the 21st century. To improve the ability to better predict wildfire across Alaska and Canada, future research should focus on incorporating additional effects of long-term and successional vegetation changes on area burned to account more fully for interactions among fire, climate, and vegetation dynamics. ?? 2009 The Authors Journal compilation ?? 2009 Blackwell Publishing Ltd.

A One-Dimensional Global-Scaling Erosive Burning Model Informed by Blowing Wall Turbulence

NASA Technical Reports Server (NTRS)

Kibbey, Timothy P.

2014-01-01

This paper makes no attempt to comprehensively review erosive burning models or the data collected in pursuit of them; the interested reader could begin with Landsbaum for a historical summary. However, a discussion and comparison to recent work by McDonald and Rettenmaier and Heister will be included, along with data generated by Strand, et. al. Suffice it to say that the search for a way to predict erosive burning in any size motor with formulas cleanly applicable to a typical 1D ballistics analysis has been long thwarted. Some models were based on testing that failed to adequately simulate the solid rocket motor environment. In most cases, no real-time burn rate measurement was available. Two popular models, even when calibrated to recent motor-like real-time burn rate data obtained by Furfaro, were shown by McMillin to be inadequate at modeling erosive burning in the Space Shuttle Reusable Solid Rocket Motor (RSRM), the Space Launch Systems' Five-Segment RSRM (RSRMV), and the five-segment Engineering Test Motor (ETM)-3. Subsequently to the data cited from Strand and Furfaro, additional motors of the same kind as Furfaro's were tested with RSRMV propellant, utilizing 7 segments per motor and 3 throat sizes. By measuring propellant web thickness with ultrasonic gages, the burn rate was determined at cross-flow Mach numbers up to Mach 0.8. Furthermore, because of the different throat sizes in otherwise identical motors, this provides a unique look at the effect of pressure and base burn rate on the erosive response. Figure 1 shows example of the data pertaining to the high Mach motor, where the port area is initially less than the throat area. The burn rate data was processed using a smoothing method developed to reduce the noise without too severely introducing end effects that limit the range of useful data. Then, an empirical ballistics scheme was used to estimate the flow condition based on the burn rate measurements and pressure measured between each segment.

Lightning Forcing in Global Fire Models: The Importance of Temporal Resolution

NASA Astrophysics Data System (ADS)

Felsberg, A.; Kloster, S.; Wilkenskjeld, S.; Krause, A.; Lasslop, G.

2018-01-01

In global fire models, lightning is typically prescribed from observational data with monthly mean temporal resolution while meteorological forcings, such as precipitation or temperature, are prescribed in a daily resolution. In this study, we investigate the importance of the temporal resolution of the lightning forcing for the simulation of burned area by varying from daily to monthly and annual mean forcing. For this, we utilize the vegetation fire model JSBACH-SPITFIRE to simulate burned area, forced with meteorological and lightning data derived from the general circulation model ECHAM6. On a global scale, differences in burned area caused by lightning forcing applied in coarser temporal resolution stay below 0.55% compared to the use of daily mean forcing. Regionally, however, differences reach up to 100%, depending on the region and season. Monthly averaged lightning forcing as well as the monthly lightning climatology cause differences through an interaction between lightning ignitions and fire prone weather conditions, accounted for by the fire danger index. This interaction leads to decreased burned area in the boreal zone and increased burned area in the Tropics and Subtropics under the coarser temporal resolution. The exclusion of interannual variability, when forced with the lightning climatology, has only a minor impact on the simulated burned area. Annually averaged lightning forcing causes differences as a direct result of the eliminated seasonal characteristics of lightning. Burned area is decreased in summer and increased in winter where fuel is available. Regions with little seasonality, such as the Tropics and Subtropics, experience an increase in burned area.

Infection Casualty Estimation (ICE) Model: Predicting Sepsis in Nuclear Detonation Burn Patient Populations using Procalcitonin as a Biomarker

DTIC Science & Technology

2017-06-06

environments may be injured or killed from the primary blast wave, thermal pulse and ionizing radiation . Burn casualties surviving the initial blast wave are...32]/1.8 degree Celsius (oC) degree Fahrenheit (oF) [T(oF) + 459.67]/1.8 kelvin (K) Radiation activity of radionuclides [curie (Ci)] 3.7 × 1010...develop casualty estimation models for improvised nuclear device (IND) scenarios. The HSRDIPT team has developed health effects models of radiation , burn

1984–2010 trends in fire burn severity and area for the conterminous US

USGS Publications Warehouse

Picotte, Joshua J.; Peterson, Birgit E.; Meier, Gretchen; Howard, Stephen M.

2016-01-01

Burn severity products created by the Monitoring Trends in Burn Severity (MTBS) project were used to analyse historical trends in burn severity. Using a severity metric calculated by modelling the cumulative distribution of differenced Normalized Burn Ratio (dNBR) and Relativized dNBR (RdNBR) data, we examined burn area and burn severity of 4893 historical fires (1984–2010) distributed across the conterminous US (CONUS) and mapped by MTBS. Yearly mean burn severity values (weighted by area), maximum burn severity metric values, mean area of burn, maximum burn area and total burn area were evaluated within 27 US National Vegetation Classification macrogroups. Time series assessments of burned area and severity were performed using Mann–Kendall tests. Burned area and severity varied by vegetation classification, but most vegetation groups showed no detectable change during the 1984–2010 period. Of the 27 analysed vegetation groups, trend analysis revealed burned area increased in eight, and burn severity has increased in seven. This study suggests that burned area and severity, as measured by the severity metric based on dNBR or RdNBR, have not changed substantially for most vegetation groups evaluated within CONUS.

Aerosol Microphysics and Radiation Integration

DTIC Science & Technology

2003-09-30

656-4769 email: reidj@nrlmry.navy.mil Award Number: N0001403WX20570 http://www.nrlmry.navy.mil/aerosol/ http://www.nrlmry.navy.mil/ flambe ...Fire Locating and Modeling of Burning Emissions ( FLAMBE ) project, which also provides NAAPS with a real-time biomass burning source function. In...Locating and Modeling of Burning Emissions ( FLAMBE ) project are currently being utilized by internet community, Air quality/human health research

The impact of diverse types of biomass burning in a tropical country

Treesearch

R. J. Yokelson; I. R. Burling; Shawn Urbanski; T. J. Christian; E. L. Atlas; C. Wiedinmyer; S. K. Akagi; G. Engling

2010-01-01

We couple laboratory work, airborne and ground-based field measurements, remote sensing of fires, and modeling to assess the impact of diverse types of biomass burning (BB) in Mexico as a model tropical country. About 70-80% of open BB occurs in the tropics along with large amounts of biofuel use and garbage burning (GB); both in rural and urban areas. During the...

Fine scale vegetation classification and fuel load mapping for prescribed burning

Treesearch

Andrew D. Bailey; Robert Mickler

2007-01-01

Fire managers in the Coastal Plain of the Southeastern United States use prescribed burning as a tool to reduce fuel loads in a variety of vegetation types, many of which have elevated fuel loads due to a history of fire suppression. While standardized fuel models are useful in prescribed burn planning, those models do not quantify site-specific fuel loads that reflect...

Large-Scale Aerosol Modeling and Analysis

DTIC Science & Technology

2010-09-30

Application of Earth Sciences Products” supports improvements in NAAPS physics and model initialization. The implementation of NAAPS, NAVDAS-AOD, FLAMBE ...Forecasting of Biomass-Burning Smoke: Description of and Lessons From the Fire Locating and Modeling of Burning Emissions ( FLAMBE ) Program, IEEE Journal of

The development of an erosive burning model for solid rocket motors using direct numerical simulation

NASA Astrophysics Data System (ADS)

McDonald, Brian A.

A method for developing an erosive burning model for use in solid propellant design-and-analysis interior ballistics codes is described and evaluated. Using Direct Numerical Simulation, the primary mechanisms controlling erosive burning (turbulent heat transfer, and finite rate reactions) have been studied independently through the development of models using finite rate chemistry, and infinite rate chemistry. Both approaches are calibrated to strand burn rate data by modeling the propellant burning in an environment with no cross-flow, and adjusting thermophysical properties until the predicted regression rate matches test data. Subsequent runs are conducted where the cross-flow is increased from M = 0.0 up to M = 0.8. The resulting relationship of burn rate increase versus Mach Number is used in an interior ballistics analysis to compute the chamber pressure of an existing solid rocket motor. The resulting predictions are compared to static test data. Both the infinite rate model and the finite rate model show good agreement when compared to test data. The propellant considered is an AP/HTPB with an average AP particle size of 37 microns. The finite rate model shows that as the cross-flow increases, near wall vorticity increases due to the lifting of the boundary caused by the side injection of gases from the burning propellant surface. The point of maximum vorticity corresponds to the outer edge of the APd-binder flame. As the cross-flow increases, the APd-binder flame thickness becomes thinner; however, the point of highest reaction rate moves only slightly closer to the propellant surface. As such, the net increase of heat transfer to the propellant surface due to finite rate chemistry affects is small. This leads to the conclusion that augmentation of thermal transport properties and the resulting heat transfer increase due to turbulence dominates over combustion chemistry in the erosive burning problem. This conclusion is advantageous in the development of future models that can be calibrated to heat transfer conditions without the necessity for finite rate chemistry. These results are considered applicable for propellants with small, evenly distributed AP particles where the assumption of premixed APd-binder gases is reasonable.

40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

Code of Federal Regulations, 2014 CFR

2014-07-01

... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

Code of Federal Regulations, 2013 CFR

2013-07-01

... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

Code of Federal Regulations, 2012 CFR

2012-07-01

... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

Code of Federal Regulations, 2010 CFR

2010-07-01

... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

40 CFR 60.3068 - What are the recordkeeping and reporting requirements for air curtain incinerators that burn only...

Code of Federal Regulations, 2011 CFR

2011-07-01

... reporting requirements for air curtain incinerators that burn only wood waste, clean lumber, and yard waste... Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3068 What are the recordkeeping and reporting requirements for air curtain incinerators that burn only wood...

Numerical Modeling of Transport of Biomass Burning Emissions on South America

NASA Technical Reports Server (NTRS)

RibeirodeFreitas, Saulo

2001-01-01

Our research efforts have addressed theoretical and numerical modeling of sources emissions and transport processes of trace gases and aerosols emitted by biomass burning on the central of Brazil and Amazon basin. For this effort we coupled all Eulerian transport model with the mesoscale atmospheric model RAMS (Regional Atmospheric Modeling System).

System parameters for erythropoiesis control model: Comparison of normal values in human and mouse model

NASA Technical Reports Server (NTRS)

1979-01-01

The computer model for erythropoietic control was adapted to the mouse system by altering system parameters originally given for the human to those which more realistically represent the mouse. Parameter values were obtained from a variety of literature sources. Using the mouse model, the mouse was studied as a potential experimental model for spaceflight. Simulation studies of dehydration and hypoxia were performed. A comparison of system parameters for the mouse and human models is presented. Aside from the obvious differences expected in fluid volumes, blood flows and metabolic rates, larger differences were observed in the following: erythrocyte life span, erythropoietin half-life, and normal arterial pO2.

A retrospective review of burn dressings on a porcine burn model.

PubMed

Wang, Xue-Qing; Kravchuk, Olena; Kimble, Roy M

2010-08-01

This is a study to compare wound healing among three types of dressings on a porcine model with deep-dermal-partial-thickness burns. The burns in this study were from eight animal trials conducted in the past for other purposes and only burns with a uniform pale appearance that had served as controls in original experiments were selected. In total, there were 57 burns in 33 pigs, using one of following three dressings: Acticoat (Silver) (3 trials), Jelonet (Gauze) (3 trials), and Solosite Gel/Jelonet (Gel/Gauze) (2 trials). The wound healing assessments included wound re-epithelialisation during a 6-week period, clinical and histological scar assessments at week 6 after burn. Of all wound healing/scar assessments, only re-epithelialisation showed statistical difference between dressings. Earlier re-epithelialisation was observed in Gel/Gauze dressings compared to Silver and/or Gauze dressings. However, this study revealed huge variation in wound healing outcome between 3 trials within both Silver and/or Gauze dressings, supported by significant differences on re-epithelialisation, clinical and histological scar measurements. In addition, it was found that larger animals healed better than smaller ones, based on weights from 21 pigs. Of all dressings, Silver delivers the best protection for wound colonization/infection. Wound colonization/infection was found to confine wound healing and lead to thinner RND in scars. From this study, we cannot find enough evidence to suggest the beneficial effect of one dressing(s) over others on burn wound healing outcome on a porcine model with small deep-dermal-partial-thickness burns with a relative small sample size.

Quantifying bacterial transfer from patients to staff during burns dressing and bed changes: implications for infection control.

PubMed

Bache, Sarah E; Maclean, Michelle; Gettinby, George; Anderson, John G; MacGregor, Scott J; Taggart, Ian

2013-03-01

Routine nursing activities such as dressing/bed changes increase bacterial dispersal from burns patients, potentially contaminating healthcare workers (HCW) carrying out these tasks. HCW thus become vectors for transmission of nosocomial infection between patients. The suspected relationship between %total body surface area (%TBSA) of burn and levels of bacterial release has never been fully established. Bacterial contamination of HCW was assessed by contact plate samples (n=20) from initially sterile gowns worn by the HCW during burns patient dressing/bed changes. Analysis of 24 gowns was undertaken and examined for relationships between %TBSA, time taken for activity, and contamination received by the HCW. Relationships between size of burn and levels of HCW contamination, and time taken for the dressing/bed change and levels of HCW contamination were best described by exponential models. Burn size correlated more strongly (R(2)=0.82, p<0.001) than time taken (R(2)=0.52, p<0.001), with levels of contamination received by the HCW. Contamination doubled with every 6-9% TBSA increase in burn size. Burn size was used to create a model to predict bacterial contamination received by a HCW carrying out bed/dressing changes. This may help with the creation of burn-specific guidelines on protective clothing worn by HCW caring for burns patients. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

FECAL MICROBIOTA TRANSPLANT RESTORES MUCOSAL INTEGRITY IN A MURINE MODEL OF BURN INJURY

PubMed Central

Kuethe, Joshua W.; Armocida, Stephanie M.; Midura, Emily F.; Rice, Teresa C.; Hildeman, David A.; Healy, Daniel P.; Caldwell, Charles C.

2016-01-01

The gut microbiome is a community of commensal organisms that are known to play a role in nutrient production as well as gut homeostasis. The composition of the gut flora can be affected by many factors; however, the impact of burn injury on the microbiome is not fully known. Here, we hypothesized that burn-induced changes to the microbiome would impact overall colon health. After scald-burn injury, cecal samples were analyzed for aerobic and anaerobic colony forming units, bacterial community, and butyrate levels. In addition, colon and total intestinal permeabilities were determined. These parameters were further determined in a germ-reduced murine model. Following both burn injury and germ reduction, we observed decreases in aerobic and anaerobic bacteria, increased colon permeability and no change to small intestinal permeability. After burn injury, we further observed a significant decrease in the butyrate producing bacteria R. Gnavus, C. Eutactus, and Roseburia species as well as decreases in colonic butyrate. Finally, in mice that underwent burn followed by fecal microbiota transplant, bacteria levels and mucosal integrity were restored. Altogether our data demonstrate that burn injury can alter the microbiome leading to decreased butyrate levels and increased colon permeability. Of interest, fecal microbiota transplant treatment was able to ameliorate the burn-induced changes in colon permeability. Thus, fecal transplantation may represent a novel therapy in restoring colon health after burn injury. PMID:26682948

Pegylated G-CSF Inhibits Blood Cell Depletion, Increases Platelets, Blocks Splenomegaly, and Improves Survival after Whole-Body Ionizing Irradiation but Not after Irradiation Combined with Burn

DTIC Science & Technology

2014-03-05

increased granulocyte colony stim- ulating factor (G-CSF) in mouse blood for more than 7 days [7]. The increase was initially believed to be a self ...hematopoietic stem cell mobilization from the bone marrow into the bloodstream. It is involved in recovery from infection [11, 12] and wound healing [13]. Peg-G...mapping data; corrections for the 60Co decay and the small differences in the mass energy absorption coefficients for water and soft tissue were

Nursing research on a first aid model of double personnel for major burn patients.

PubMed

Wu, Weiwei; Shi, Kai; Jin, Zhenghua; Liu, Shuang; Cai, Duo; Zhao, Jingchun; Chi, Cheng; Yu, Jiaao

2015-03-01

This study explored the effect of a first aid model employing two nurses on the efficient rescue operation time and the efficient resuscitation time for major burn patients. A two-nurse model of first aid was designed for major burn patients. The model includes a division of labor between the first aid nurses and the re-organization of emergency carts. The clinical effectiveness of the process was examined in a retrospective chart review of 156 cases of major burn patients, experiencing shock and low blood volume, who were admitted to the intensive care unit of the department of burn surgery between November 2009 and June 2013. Of the 156 major burn cases, 87 patients who received first aid using the double personnel model were assigned to the test group and the 69 patients who received first aid using the standard first aid model were assigned to the control group. The efficient rescue operation time and the efficient resuscitation time for the patients were compared between the two groups. Student's t tests were used to the compare the mean difference between the groups. Statistically significant differences between the two groups were found on both measures (P's < 0.05), with the test group having lower times than the control group. The efficient rescue operation time was 14.90 ± 3.31 min in the test group and 30.42 ± 5.65 min in the control group. The efficient resuscitation time was 7.4 ± 3.2 h in the test group and 9.5 ± 2.7 h in the control group. A two-nurse first aid model based on scientifically validated procedures and a reasonable division of labor can shorten the efficient rescue operation time and the efficient resuscitation time for major burn patients. Given these findings, the model appears to be worthy of clinical application.

A review of direct numerical simulations of astrophysical detonations and their implications

DOE PAGES

Parete-Koon, Suzanne T.; Smith, Christopher R.; Papatheodore, Thomas L.; ...

2013-04-11

Multi-dimensional direct numerical simulations (DNS) of astrophysical detonations in degenerate matter have revealed that the nuclear burning is typically characterized by cellular structure caused by transverse instabilities in the detonation front. Type Ia supernova modelers often use one- dimensional DNS of detonations as inputs or constraints for their whole star simulations. While these one-dimensional studies are useful tools, the true nature of the detonation is multi-dimensional. The multi-dimensional structure of the burning influences the speed, stability, and the composition of the detonation and its burning products, and therefore, could have an impact on the spectra of Type Ia supernovae. Considerablemore » effort has been expended modeling Type Ia supernovae at densities above 1x10 7 g∙cm -3 where the complexities of turbulent burning dominate the flame propagation. However, most full star models turn the nuclear burning schemes off when the density falls below 1x10 7 g∙cm -3 and distributed burning begins. The deflagration to detonation transition (DDT) is believed to occur at just these densities and consequently they are the densities important for studying the properties of the subsequent detonation. In conclusion, this work reviews the status of DNS studies of detonations and their possible implications for Type Ia supernova models. It will cover the development of Detonation theory from the first simple Chapman-Jouguet (CJ) detonation models to the current models based on the time-dependent, compressible, reactive flow Euler equations of fluid dynamics.« less

Astaxanthin protects against early burn-wound progression in rats by attenuating oxidative stress-induced inflammation and mitochondria-related apoptosis

PubMed Central

Fang, Quan; Guo, Songxue; Zhou, Hanlei; Han, Rui; Wu, Pan; Han, Chunmao

2017-01-01

Burn-wound progression can occur in the initial or peri-burn area after a deep burn injury. The stasis zone has a higher risk of deterioration mediated by multiple factors but is also considered salvageable. Astaxanthin (ATX), which is extracted from some marine organisms, is a natural compound with a strong antioxidant effect that has been reported to attenuate organ injuries caused by traumatic injuries. Hence, we investigated the potential effects of ATX on preventing early burn-wound progression. A classic “comb” burn rat model was established in this study for histological and biological assessments, which revealed that ATX, particularly higher doses, alleviated histological deterioration in the stasis zone. Additionally, we observed dose-dependent improvements in oxidative stress and the release of inflammatory mediators after ATX treatment. Furthermore, ATX dose-dependently attenuated burn-induced apoptosis in the wound areas, and this effect was accompanied by increases in Akt and Bad phosphorylation and a downregulation of cytochrome C and caspase expression. In addition, the administration of Ly 294002 further verified the effect of ATX. In summary, we demonstrated that ATX protected against early burn-wound progression in a rat deep-burn model. This protection might be mediated by the attenuation of oxidative stress-induced inflammation and mitochondria-related apoptosis. PMID:28128352

Erosive Burning of Composite Solid Propellants: Experimental and Modeling Studies

DTIC Science & Technology

1978-08-01

of Crossflow on Solid Pro- appears that an additional mechanism(s) of erosive pallant Combustion: Interior Ballistic Design burning will have to be...Orlondo, Florida, July , 1977, AIAA Paper 77-930. 14. Lengelle,G., "Model Describing the Erosive Com- bustion and Velocity Response of Composite Pro...Propulsion Conference, Orlando, Florida, July , 1977. 17. Beddini, R.A., A Reacting Turbulent Boundary Layer Approach to Solid Propellant Erosive Burning, AFOSR

40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 [Date to be specified in state...

40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 [Date to be specified in state...

40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 For the air pollutant You must...

Human mammary microenvironment better regulates the biology of human breast cancer in humanized mouse model.

PubMed

Zheng, Ming-Jie; Wang, Jue; Xu, Lu; Zha, Xiao-Ming; Zhao, Yi; Ling, Li-Jun; Wang, Shui

2015-02-01

During the past decades, many efforts have been made in mimicking the clinical progress of human cancer in mouse models. Previously, we developed a human breast tissue-derived (HB) mouse model. Theoretically, it may mimic the interactions between "species-specific" mammary microenvironment of human origin and human breast cancer cells. However, detailed evidences are absent. The present study (in vivo, cellular, and molecular experiments) was designed to explore the regulatory role of human mammary microenvironment in the progress of human breast cancer cells. Subcutaneous (SUB), mammary fat pad (MFP), and HB mouse models were developed for in vivo comparisons. Then, the orthotopic tumor masses from three different mouse models were collected for primary culture. Finally, the biology of primary cultured human breast cancer cells was compared by cellular and molecular experiments. Results of in vivo mouse models indicated that human breast cancer cells grew better in human mammary microenvironment. Cellular and molecular experiments confirmed that primary cultured human breast cancer cells from HB mouse model showed a better proliferative and anti-apoptotic biology than those from SUB to MFP mouse models. Meanwhile, primary cultured human breast cancer cells from HB mouse model also obtained the migratory and invasive biology for "species-specific" tissue metastasis to human tissues. Comprehensive analyses suggest that "species-specific" mammary microenvironment of human origin better regulates the biology of human breast cancer cells in our humanized mouse model of breast cancer, which is more consistent with the clinical progress of human breast cancer.

An evaluation of the uncertainties in biomass burning emissions

NASA Astrophysics Data System (ADS)

Yano, A.; Garcia Menendez, F.; Hu, Y.; Odman, M.

2012-12-01

The contribution of biomass burning emissions to the atmospheric loads of gases and aerosols can lead to major air quality problems and have significant climate impacts. Whether from wildfires, natural or human-induced, or controlled burns, biomass burning emissions are an important source of air pollutants regionally in certain parts of the world as well as globally. There are two common ways of estimating biomass burning emissions: by using either ground-based information or satellite observations. When there is sufficient local information about the burn area, the types of fuels and their consumption amounts, and the progression of the fire, ground-based estimation is preferred. For controlled burns a.k.a. prescribed burns and wildfires in places where land management is practiced to a certain extent there is typically sufficient ground-based information for emissions estimation. However, for remote regions where no ground-based information is available on the size, intensity, or the spread of the fire, estimates based on satellite observations are preferred. For example, burn location, size and timing information can be obtained from satellite retrievals of thermal anomalies and fuel loading information can be obtained from satellite products of vegetation cover. In both cases, reasonable emission estimates for a variety of pollutants can be obtained by using emission factors (mass of pollutant released per unit mass of fuel consumed) derived from field or laboratory studies. Here, emissions from a controlled burn and a wildfire are estimated using both ground-based information and satellite observations. The controlled burn was conducted on 17 November 2009 near Santa Barbara, California over 80 ha of land covered with chaparral. An aircraft tracked the smoke plume and measured CO2, light scattering, as well as meteorological parameters during the burn (Akagi et al., 2011). The wildfire is from the summer of 2008 when tens of thousands hectares of wild land burned in Northern California causing unprecedented damage. NASA Aircraft commissioned for the ARCTAS campaign at the time flew over the fires and collected data detailing composition of gases and aerosols in the fire plumes (Singh et al., 2012). We model the fires using a newly developed system consisting of a plume rise and dispersion model specifically designed for wild-land fire plumes (Daysmoke; Achtemeier et al., 2011) coupled with a regional-scale chemistry-transport model (CMAQ). Wind fields generated by a weather prediction model (WRF) are adjusted locally to match the aircraft measurements of wind speed and direction. The fires are simulated using both ground-based and satellite-based estimates of emissions. Predicted concentrations of gases and aerosols are compared to corresponding aircraft measurements. Satellite retrievals of aerosol optical depth are also used in evaluating model predictions. The new modeling system along with the wind adjustments reduces several of the uncertainties inherent to regional-scale modeling of plume transport. This allows for a more reliable analysis of the uncertainties related to emissions. Uncertainties in the magnitudes and timings of emissions, and in plume injection heights with respect to boundary layer heights are investigated. Uncertainties associated with ground-based and satellite-based emissions estimation methods are compared to each other.

40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2012 CFR

2012-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2014 CFR

2014-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

40 CFR 60.1920 - What are the emission limits for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2012 CFR

2012-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1920 Section 60.1920 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1920 What are the emission limits for air curtain incinerators that burn 100 percent yard waste? If...

40 CFR 60.1920 - What are the emission limits for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2014 CFR

2014-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1920 Section 60.1920 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1920 What are the emission limits for air curtain incinerators that burn 100 percent yard waste? If...

40 CFR 60.1920 - What are the emission limits for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2013 CFR

2013-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1920 Section 60.1920 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1920 What are the emission limits for air curtain incinerators that burn 100 percent yard waste? If...

40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2010 CFR

2010-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2013 CFR

2013-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2011 CFR

2011-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use...

40 CFR 60.1920 - What are the emission limits for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2011 CFR

2011-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1920 Section 60.1920 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1920 What are the emission limits for air curtain incinerators that burn 100 percent yard waste? If...

40 CFR 60.1920 - What are the emission limits for air curtain incinerators that burn 100 percent yard waste?

Code of Federal Regulations, 2010 CFR

2010-07-01

... curtain incinerators that burn 100 percent yard waste? 60.1920 Section 60.1920 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1920 What are the emission limits for air curtain incinerators that burn 100 percent yard waste? If...

Satellite Contributions to the Quantitative Characterization of Biomass Burning for Climate Modeling

NASA Technical Reports Server (NTRS)

Ichoku, Charles; Kahn, Ralph; Chin, Mian

2012-01-01

Characterization of biomass burning from space has been the subject of an extensive body of literature published over the last few decades. Given the importance of this topic, we review how satellite observations contribute toward improving the representation of biomass burning quantitatively in climate and air-quality modeling and assessment. Satellite observations related to biomass burning may be classified into five broad categories: (i) active fire location and energy release, (ii) burned areas and burn severity, (iii) smoke plume physical disposition, (iv) aerosol distribution and particle properties, and (v) trace gas concentrations. Each of these categories involves multiple parameters used in characterizing specific aspects of the biomass-burning phenomenon. Some of the parameters are merely qualitative, whereas others are quantitative, although all are essential for improving the scientific understanding of the overall distribution (both spatial and temporal) and impacts of biomass burning. Some of the qualitative satellite datasets, such as fire locations, aerosol index, and gas estimates have fairly long-term records. They date back as far as the 1970s, following the launches of the DMSP, Landsat, NOAA, and Nimbus series of earth observation satellites. Although there were additional satellite launches in the 1980s and 1990s, space-based retrieval of quantitative biomass burning data products began in earnest following the launch of Terra in December 1999. Starting in 2000, fire radiative power, aerosol optical thickness and particle properties over land, smoke plume injection height and profile, and essential trace gas concentrations at improved resolutions became available. The 2000s also saw a large list of other new satellite launches, including Aqua, Aura, Envisat, Parasol, and CALIPSO, carrying a host of sophisticated instruments providing high quality measurements of parameters related to biomass burning and other phenomena. These improved data products have enabled significant progress in the study of biomass burning from space. However, appreciable uncertainty remains in many of the measurements that still needs to be addressed. Nevertheless, climate and other atmospheric models are

Explanatory Model of Resilience in Pediatric Burn Survivors.

PubMed

Quezada, Lucía; González, Mónica T; Mecott, Gabriel A

2016-01-01

Identifying factors of adjustment in pediatric burn patients may facilitate appropriate mental health interventions postinjury. The aim of this is study was to explore the roles of both the patient's and caregivers' resilience and posttraumatic stress in pediatric burn survivor adjustment. For the purposes of the study, "51 patient-parent/guardian" dyads participated. Patients answered the Resilience Questionnaire for Children and Adolescents, and caregivers answered the Mexican Resilience Scale and the Davidson Trauma Scale. The roles of patient age, time since the burn, and size of burn injury were also considered. Statistical analyses included Spearman's ρ for correlations and structural equation modeling. P less than .05 was considered significant. Patients and caregivers reported high levels of resilience, and the majority of caregivers reported low severity of posttraumatic stress disorder symptoms. Pediatric burn survivors' resilience was associated with being younger at the time of the burn and less severity of intrusive and avoidance symptoms in caregivers; it was also associated with a higher resilience in caregivers. It can be concluded that psychological responses of caregivers of pediatric burn survivors affect the well being and positive adjustment of patients; thus psychological services for caregivers would likely have a double benefit for both caregivers and patients.

Social participation, social support, and body image in the first year of rehabilitation in burn survivors: A longitudinal, three-wave cross-lagged panel analysis using structural equation modeling.

PubMed

Ajoudani, Fardin; Jasemi, Madineh; Lotfi, Mojgan

2018-05-15

Psychosocial outcomes of burn survivors in the first year of rehabilitation are not well studied. Considering the interrelationships among psychosocial processes in burn survivors, we assessed three psychosocial variables (i.e., social support, social participation, and body image) simultaneously in a longitudinal study. This study aimed at identifying the developmental trajectory of the main study variables and also discovering the causal pathways between social support, body image, and social participation of burn survivors in the first year of rehabilitation. One hundred individuals were enrolled in the study. The analysis was based on three waves of data collected at the time of discharge, 6 months after discharge, and 12 months after discharge. We used MSPSS, SWAP, and the p-scale for measuring the variables social support, body image, and social participation, respectively. A repeated-measures analysis of variance (ANOVA) was performed to identify the major differences in the mean levels of the main study variables across the three evaluation times. A structural equation modeling (SEM) approach was implemented in four hypothesized cross-lagged models (M1, M2, M3, and M4) to evaluate the bidirectional relationships among the main variables. All hypothesized models were tested, and their goodness-of-fit indexes were compared to identify the best fitting model. All three main variables worsen during the first six months after burn and then do not return to their earlier level. The M4 (final model) chosen to represent the data showed the best goodness-of-fit indexes (χ 2 (9)=51.76, p<.01, RMSEA=0.060, IFI=0.97, and CFI=0.98) among all hypothesized models. The effect of social participation on body image, and vice versa, seems to be relatively constant and steady. Social support at the time of discharge predicted social participation at 12 months after burn, with the relationship mediated by body image at 6 months after burn. Our study findings suggest that persistent care should be provided for burn survivors even after discharge. Copyright © 2018 Elsevier Ltd and ISBI. All rights reserved.

Modeling the spreading of large-scale wildland fires

Treesearch

Mohamed Drissi

2015-01-01

The objective of the present study is twofold. First, the last developments and validation results of a hybrid model designed to simulate fire patterns in heterogeneous landscapes are presented. The model combines the features of a stochastic small-world network model with those of a deterministic semi-physical model of the interaction between burning and non-burning...

In vivo classification of human skin burns using machine learning and quantitative features captured by optical coherence tomography

NASA Astrophysics Data System (ADS)

Singla, Neeru; Srivastava, Vishal; Singh Mehta, Dalip

2018-02-01

We report the first fully automated detection of human skin burn injuries in vivo, with the goal of automatic surgical margin assessment based on optical coherence tomography (OCT) images. Our proposed automated procedure entails building a machine-learning-based classifier by extracting quantitative features from normal and burn tissue images recorded by OCT. In this study, 56 samples (28 normal, 28 burned) were imaged by OCT and eight features were extracted. A linear model classifier was trained using 34 samples and 22 samples were used to test the model. Sensitivity of 91.6% and specificity of 90% were obtained. Our results demonstrate the capability of a computer-aided technique for accurately and automatically identifying burn tissue resection margins during surgical treatment.

The Development of the Wall Momentum Erosive Burning Scaling Law and Macro Scale Erosive Burning Model

DTIC Science & Technology

2010-05-01

burn rate in excess of 2 in/sec at 1000 psi, and Mach numbers that reach 1.0 at the aft end at ignition . Typically, motors with high burning rate...37 VI I. INTRODUCTION Interior ballistics of solid propellant rocket motors continues to be an engineering discipline that is...and one open source paper published between 2005 and 2009 [2, 3, 13]. II. BACKGROUND Erosive burning is a term used in the solid rocket motor

The Mouse Tumor Biology Database: A Comprehensive Resource for Mouse Models of Human Cancer.

PubMed

Krupke, Debra M; Begley, Dale A; Sundberg, John P; Richardson, Joel E; Neuhauser, Steven B; Bult, Carol J

2017-11-01

Research using laboratory mice has led to fundamental insights into the molecular genetic processes that govern cancer initiation, progression, and treatment response. Although thousands of scientific articles have been published about mouse models of human cancer, collating information and data for a specific model is hampered by the fact that many authors do not adhere to existing annotation standards when describing models. The interpretation of experimental results in mouse models can also be confounded when researchers do not factor in the effect of genetic background on tumor biology. The Mouse Tumor Biology (MTB) database is an expertly curated, comprehensive compendium of mouse models of human cancer. Through the enforcement of nomenclature and related annotation standards, MTB supports aggregation of data about a cancer model from diverse sources and assessment of how genetic background of a mouse strain influences the biological properties of a specific tumor type and model utility. Cancer Res; 77(21); e67-70. ©2017 AACR . ©2017 American Association for Cancer Research.

On the influence of biomass burning on the seasonal CO2 signal as observed at monitoring stations

USGS Publications Warehouse

Wittenberg, U.; Heimann, Martin; Esse, G.; McGuire, A.D.; Sauf, W.

1998-01-01

We investigated the role of biomass burning in simulating the seasonal signal in both prognostic and diagnostic analyses. The prognostic anaysis involved the High-Resolution Biosphere Model, a prognostic terrestrial biosphere model, and the coupled vegetation fire module, which together produce a prognostic data set of biomass burning. The diagnostic analysis invovled the Simple Diagnostic Biosphere Model (SDBM) and the Hao and Liu [1994] diagnostic data set of bimass burning, which have been scaled to global 2 and 4 Pg C yr-1, respectively. The monthly carbon exchange fields between the atmosphere and the biosphere with a spatial resolution of 0.5?? ?? 0.5??, the seasonal atmosphere-ocean exchange fields, and the emissions from fossil fuels have been coupled to the three-dimensional atmospheric transport model TM2. We have chosen eight monitoring stations of the National Oceanic and Atmospheric Administration network to compare the predicted seasonal atmospheric CO2 signals with those deduced from atmosphere-biosphere carbon exchange fluxes without any contribution from biomass burning. The prognostic analysis and the diagnostic analysis with global burning emissions of 4 Pg C yr-1 agree with respect to the change in the amplitude of the seasonal CO2 concentration introduced through biomass burning. We find that the seasonal CO2 signal at stations in higher northern latitudes (north of 30??N) is marginally influenced by biomass burning. For stations in tropical regions an increase in the CO2 amplitude of more an 1 oppmv (up to 50% with respect to the observed trough to peak amplitude) has been calculated. Biomass burning at stations farther south accounts for an increase in the CO2 amplitude of up to 59% (0.6 ppmv). A change in the phase of the seasonal CO2 signal at tropical and southern stations has been shown to be strongly influenced by the onset of biomass burning in southern tropical Africa and America. Comparing simulated and observed seasonal CO2 signals, we find higher discrepancies at southern troical stations if biomass burning emissions are included. This is caused by the additional increase in the amplitude in the prognostic analysis and a phase shift in a diagnostic analysis. In contrast, at the northern tropical stations biomass burning tends to improve the estimates of the seasonal CO2 signal in the prognostic analysis because of strengthening of the amplitude. Since the SDCM predicts the seasonal CO2 signal resonably well for the northern hemisphere tropical stations, no general improvement of the fit occurs if biomass burning emissions are considered.

User assessment of smoke-dispersion models for wildland biomass burning.

Treesearch

Steve Breyfogle; Sue A. Ferguson

1996-01-01

Several smoke-dispersion models, which currently are available for modeling smoke from biomass burns, were evaluated for ease of use, availability of input data, and output data format. The input and output components of all models are listed, and differences in model physics are discussed. Each model was installed and run on a personal computer with a simple-case...

Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke

Treesearch

G L Achtemeier; S L Goodrick; Y Liu; F Garcia-Menendez; Y Hu; M. Odman

2011-01-01

We present Daysmoke, an empirical-statistical plume rise and dispersion model for simulating smoke from prescribed burns. Prescribed fires are characterized by complex plume structure including multiple-core updrafts which makes modeling with simple plume models difficult. Daysmoke accounts for plume structure in a three-dimensional veering/sheering atmospheric...

Development of a reactive burn model based on an explicit viscoplastic pore collapse model

NASA Astrophysics Data System (ADS)

Bouton, E.; Lefrançois, A.; Belmas, R.

2017-01-01

The aim of this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the shock-initiation of pressed TATB high explosives. Such a model has been implemented in a lagrangian hydrodynamic code. In our calculations, 8 pore radii, ranging from 40 nm to 0.63 μm, have been taken into account and the porosity fraction associated to each void radius has been deduced from the Ultra-Small-Angle X-ray Scattering measurements (USAXS) for PBX-9502. The last parameter of our model is a burn rate that depends on three variables. The first two are the reaction progress variable and the lead shock pressure, the last one is the chemical reaction site number produced in the flow and calculated by the microscopic model. This burn rate has been calibrated by fitting pressure, velocity profiles and run distances to detonation. As the computed results are in close agreement with the measured ones, this model is able to perform a wide variety of numerical simulations including single, double shock waves and the desensitization phenomenon.

Applying Quality Function Deployment Model in Burn Unit Service Improvement.

PubMed

Keshtkaran, Ali; Hashemi, Neda; Kharazmi, Erfan; Abbasi, Mehdi

2016-01-01

Quality function deployment (QFD) is one of the most effective quality design tools. This study applies QFD technique to improve the quality of the burn unit services in Ghotbedin Hospital in Shiraz, Iran. First, the patients' expectations of burn unit services and their priorities were determined through Delphi method. Thereafter, burn unit service specifications were determined through Delphi method. Further, the relationships between the patients' expectations and service specifications and also the relationships between service specifications were determined through an expert group's opinion. Last, the final importance scores of service specifications were calculated through simple additive weighting method. The findings show that burn unit patients have 40 expectations in six different areas. These expectations are in 16 priority levels. Burn units also have 45 service specifications in six different areas. There are four-level relationships between the patients' expectations and service specifications and four-level relationships between service specifications. The most important burn unit service specifications have been identified in this study. The QFD model developed in the study can be a general guideline for QFD planners and executives.

Influence of fire frequency on carbon consumption in Alaskan blackspruce forests

NASA Astrophysics Data System (ADS)

Hoy, E.; Kasischke, E. S.

2014-12-01

Increasing temperatures and drier conditions within the boreal forests of Alaska have resulted in increases in burned area and fire frequency, which alter carbon storage and emissions. In particular, analyses of satellite remote sensing data showed that >20% of the area impacted by fires in interior Alaska occurred in areas that had previously burned since 1950 (e.g., short to intermediate interval fires). Field studies showed that in immature black spruce forests ~ 35 to 55 years old organic layers experienced deep burning regardless of topographic position or seasonality of burning, factors that control depth of burning in mature black spruce forests. Here, refinements were made to a carbon consumption model to account for variations in fuel loads and fraction of carbon consumed associated with fire frequency based on quantifying burned area in recently burned sites using satellite imagery. An immature black spruce (Picea mariana) fuel type (including stands of ~0-50 years) was developed which contains new ground-layer carbon consumption values in order to more accurately account for differences between various age classes of black spruce forest. Both versions of the model were used to assess carbon consumption during 100 fire events (over 4.4 x 10^6 ha of burned area) from two recent ultra-large fire years (2004 and 2005). Using the improved model to better attribute fuel type and consumption resulted in higher ground-layer carbon consumption (4.9% in 2004 and 6.8% in 2005) than previously estimated. These adjustments in ground-layer burning resulted in total carbon consumption within 2004 and 2005 of 63.5 and 42.0 Tg of carbon, respectively. Results from this research could be incorporated into larger scale modeling efforts to better assess changes in the climate-fire-vegetation dynamics in interior Alaskan boreal forests, and to understand the impacts of these changes on carbon consumption and emissions.

Modeling Smoke Plume-Rise and Dispersion from Southern United States Prescribed Burns with Daysmoke.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Achtemeier, Gary, L.; Goodrick, Scott, A.; Liu, Yongqiang

2011-08-19

We present Daysmoke, an empirical-statistical plume rise and dispersion model for simulating smoke from prescribed burns. Prescribed fires are characterized by complex plume structure including multiple-core updrafts which makes modeling with simple plume models difficult. Daysmoke accounts for plume structure in a three-dimensional veering/sheering atmospheric environment, multiple-core updrafts, and detrainment of particulate matter. The number of empirical coefficients appearing in the model theory is reduced through a sensitivity analysis with the Fourier Amplitude Sensitivity Test (FAST). Daysmoke simulations for 'bent-over' plumes compare closely with Briggs theory although the two-thirds law is not explicit in Daysmoke. However, the solutions for themore » 'highly-tilted' plume characterized by weak buoyancy, low initial vertical velocity, and large initial plume diameter depart considerably from Briggs theory. Results from a study of weak plumes from prescribed burns at Fort Benning GA showed simulated ground-level PM2.5 comparing favorably with observations taken within the first eight kilometers of eleven prescribed burns. Daysmoke placed plume tops near the lower end of the range of observed plume tops for six prescribed burns. Daysmoke provides the levels and amounts of smoke injected into regional scale air quality models. Results from CMAQ with and without an adaptive grid are presented.« less

BEHAVE: fire behavior prediction and fuel modeling system-BURN Subsystem, part 1

Treesearch

Patricia L. Andrews

1986-01-01

Describes BURN Subsystem, Part 1, the operational fire behavior prediction subsystem of the BEHAVE fire behavior prediction and fuel modeling system. The manual covers operation of the computer program, assumptions of the mathematical models used in the calculations, and application of the predictions.

Harborview Burns – 1974 to 2009

PubMed Central

Engrav, Loren H.; Heimbach, David M.; Rivara, Frederick P.; Kerr, Kathleen F.; Osler, Turner; Pham, Tam N.; Sharar, Sam R.; Esselman, Peter C.; Bulger, Eileen M.; Carrougher, Gretchen J.; Honari, Shari; Gibran, Nicole S.

2012-01-01

Background Burn demographics, prevention and care have changed considerably since the 1970s. The objectives were to 1) identify new and confirm previously described changes, 2) make comparisons to the American Burn Association National Burn Repository, 3) determine when the administration of fluids in excess of the Baxter formula began and to identify potential causes, and 4) model mortality over time, during a 36-year period (1974–2009) at the Harborview Burn Center in Seattle, WA, USA. Methods and Findings 14,266 consecutive admissions were analyzed in five-year periods and many parameters compared to the National Burn Repository. Fluid resuscitation was compared in five-year periods from 1974 to 2009. Mortality was modeled with the rBaux model. Many changes are highlighted at the end of the manuscript including 1) the large increase in numbers of total and short-stay admissions, 2) the decline in numbers of large burn injuries, 3) that unadjusted case fatality declined to the mid-1980s but has changed little during the past two decades, 4) that race/ethnicity and payer status disparity exists, and 5) that the trajectory to death changed with fewer deaths occurring after seven days post-injury. Administration of fluids in excess of the Baxter formula during resuscitation of uncomplicated injuries was evident at least by the early 1990s and has continued to the present; the cause is likely multifactorial but pre-hospital fluids, prophylactic tracheal intubation and opioids may be involved. Conclusions 1) The dramatic changes include the rise in short-stay admissions; as a result, the model of burn care practiced since the 1970s is still required but is no longer sufficient. 2) Fluid administration in excess of the Baxter formula with uncomplicated injuries began at least two decades ago. 3) Unadjusted case fatality declined to ∼6% in the mid-1980s and changed little since then. The rBaux mortality model is quite accurate. PMID:22792216

Human impact on wildfires varies between regions and with vegetation productivity

NASA Astrophysics Data System (ADS)

Lasslop, Gitta; Kloster, Silvia

2017-11-01

We assess the influence of humans on burned area simulated with a dynamic global vegetation model. The human impact in the model is based on population density and cropland fraction, which were identified as important drivers of burned area in analyses of global datasets, and are commonly used in global models. After an evaluation of the sensitivity to these two variables we extend the model by including an additional effect of the cropland fraction on the fire duration. The general pattern of human influence is similar in both model versions: the strongest human impact is found in regions with intermediate productivity, where fire occurrence is not limited by fuel load or climatic conditions. Human effects in the model increases burned area in the tropics, while in temperate regions burned area is reduced. While the population density is similar on average for the tropical and temperate regions, the cropland fraction is higher in temperate regions, and leads to a strong suppression of fire. The model shows a low human impact in the boreal region, where both population density and cropland fraction is very low and the climatic conditions, as well as the vegetation productivity limit fire. Previous studies attributed a decrease in fire activity found in global charcoal datasets to human activity. This is confirmed by our simulations, which only show a decrease in burned area when the human influence on fire is accounted for, and not with only natural effects on fires. We assess how the vegetation-fire feedback influences the results, by comparing simulations with dynamic vegetation biogeography to simulations with prescribed vegetation. The vegetation-fire feedback increases the human impact on burned area by 10% for present day conditions. These results emphasize that projections of burned area need to account for the interactions between fire, climate, vegetation and humans.

Modeling Multiple-Core Updraft Plume Rise for an Aerial Ignition Prescribed Burn by Coupling Daysmoke with a Cellular Automata Fire Model

Treesearch

G. L Achtemeier; S. L. Goodrick; Y. Liu

2012-01-01

Smoke plume rise is critically dependent on plume updraft structure. Smoke plumes from landscape burns (forest and agricultural burns) are typically structured into “sub-plumes” or multiple-core updrafts with the number of updraft cores depending on characteristics of the landscape, fire, fuels, and weather. The number of updraft cores determines the efficiency of...

Seasonal and interannual variations in CO and BC emissions from open biomass burning in Southern Africa during 1998-2005

NASA Astrophysics Data System (ADS)

Ito, Akinori; Ito, Akihiko; Akimoto, Hajime

2007-06-01

We estimate the emissions of carbon monoxide (CO) and black carbon (BC) from open vegetation fires in the Southern Hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5-degree resolution are estimated from the Visible InfraRed Scanner (VIRS) fire count product and the MODerate resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distributions are derived from a 0.5-degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factors and emission factors are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annually averaged effective CO and BC emissions per area burned are 27 g CO m-2 and 0.17 g BC m-2 which are consistent with the products of fuel consumption and emission factors typically measured in southern Africa. The CO and BC emissions from open vegetation burning in southern Africa range from 45 Tg CO yr-1 and 0.26 Tg BC yr-1 for 2002 to 75 Tg CO yr-1 and 0.42 Tg BC yr-1 for 1998. The monthly averaged burned areas from VIRS fire counts peak earlier than modeled CO emissions. This characteristic delay between burned areas and emissions is mainly explained by significant changes in combustion factors for woodlands in our model. Consequently, the peaks in CO and BC emissions from our bottom-up approach are identical to those from previous top-down estimates using the Measurement Of the Pollution In The Troposphere (MOPITT) and the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data.

Burns education for non-burn specialist clinicians in Western Australia.

PubMed

McWilliams, Tania; Hendricks, Joyce; Twigg, Di; Wood, Fiona

2015-03-01

Burn patients often receive their initial care by non-burn specialist clinicians, with increasingly collaborative burn models of care. The provision of relevant and accessible education for these clinicians is therefore vital for optimal patient care. A two phase design was used. A state-wide survey of multidisciplinary non-burn specialist clinicians throughout Western Australia identified learning needs related to paediatric burn care. A targeted education programme was developed and delivered live via videoconference. Pre-post-test analysis evaluated changes in knowledge as a result of attendance at each education session. Non-burn specialist clinicians identified numerous areas of burn care relevant to their practice. Statistically significant differences between perceived relevance of care and confidence in care provision were reported for aspects of acute burn care. Following attendance at the education sessions, statistically significant increases in knowledge were noted for most areas of acute burn care. Identification of learning needs facilitated the development of a targeted education programme for non-burn specialist clinicians. Increased non-burn specialist clinician knowledge following attendance at most education sessions supports the use of videoconferencing as an acceptable and effective method of delivering burns education in Western Australia. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Simulation of mixing in the quick quench region of a rich burn-quick quench mix-lean burn combustor

NASA Technical Reports Server (NTRS)

Shih, Tom I.-P.; Nguyen, H. Lee; Howe, Gregory W.; Li, Z.

1991-01-01

A computer program was developed to study the mixing process in the quick quench region of a rich burn-quick quench mix-lean burn combustor. The computer program developed was based on the density-weighted, ensemble-averaged conservation equations of mass, momentum (full compressible Navier-Stokes), total energy, and species, closed by a k-epsilon turbulence model with wall functions. The combustion process was modeled by a two-step global reaction mechanism, and NO(x) formation was modeled by the Zeldovich mechanism. The formulation employed in the computer program and the essence of the numerical method of solution are described. Some results obtained for nonreacting and reacting flows with different main-flow to dilution-jet momentum flux ratios are also presented.

How Much Global Burned Area Can Be Forecast on Seasonal Time Scales Using Sea Surface Temperatures?

NASA Technical Reports Server (NTRS)

Chen, Yang; Morton, Douglas C.; Andela, Niels; Giglio, Louis; Randerson, James T.

2016-01-01

Large-scale sea surface temperature (SST) patterns influence the interannual variability of burned area in many regions by means of climate controls on fuel continuity, amount, and moisture content. Some of the variability in burned area is predictable on seasonal timescales because fuel characteristics respond to the cumulative effects of climate prior to the onset of the fire season. Here we systematically evaluated the degree to which annual burned area from the Global Fire Emissions Database version 4 with small fires (GFED4s) can be predicted using SSTs from 14 different ocean regions. We found that about 48 of global burned area can be forecast with a correlation coefficient that is significant at a p < 0.01 level using a single ocean climate index (OCI) 3 or more months prior to the month of peak burning. Continental regions where burned area had a higher degree of predictability included equatorial Asia, where 92% of the burned area exceeded the correlation threshold, and Central America, where 86% of the burned area exceeded this threshold. Pacific Ocean indices describing the El Nino-Southern Oscillation were more important than indices from other ocean basins, accounting for about 1/3 of the total predictable global burned area. A model that combined two indices from different oceans considerably improved model performance, suggesting that fires in many regions respond to forcing from more than one ocean basin. Using OCI-burned area relationships and a clustering algorithm, we identified 12 hotspot regions in which fires had a consistent response to SST patterns. Annual burned area in these regions can be predicted with moderate confidence levels, suggesting operational forecasts may be possible with the aim of improving ecosystem management.

Myocardial Autophagy after Severe Burn in Rats

PubMed Central

Zhang, Qiong; Shi, Xiao-hua; Huang, Yue-sheng

2012-01-01

Background Autophagy plays a major role in myocardial ischemia and hypoxia injury. The present study investigated the effects of autophagy on cardiac dysfunction in rats after severe burn. Methods Protein expression of the autophagy markers LC3 and Beclin 1 were determined at 0, 1, 3, 6, and 12 h post-burn in Sprague Dawley rats subjected to 30% total body surface area 3rd degree burns. Autophagic, apoptotic, and oncotic cell death were evaluated in the myocardium at each time point by immunofluorescence. Changes of cardiac function were measured in a Langendorff model of isolated heart at 6 h post-burn, and the autophagic response was measured following activation by Rapamycin and inhibition by 3-methyladenine (3-MA). The angiotensin converting enzyme inhibitor enalaprilat, the angiotensin receptor I blocker losartan, and the reactive oxygen species inhibitor diphenylene iodonium (DPI) were also applied to the ex vivo heart model to examine the roles of these factors in post-burn cardiac function. Results Autophagic cell death was first observed in the myocardium at 3 h post-burn, occurring in 0.008 ± 0.001% of total cardiomyocytes, and continued to increase to a level of 0.022 ± 0.005% by 12 h post-burn. No autophagic cell death was observed in control hearts. Compared with apoptosis, autophagic cell death occurred earlier and in larger quantities. Rapamycin enhanced autophagy and decreased cardiac function in isolated hearts 6 h post-burn, while 3-MA exerted the opposite response. Enalaprilat, losartan, and DPI all inhibited autophagy and enhanced heart function. Conclusion Myocardial autophagy is enhanced in severe burns and autophagic cell death occurred early at 3 h post-burn, which may contribute to post-burn cardiac dysfunction. Angiotensin II and reactive oxygen species may play important roles in this process by regulating cell signaling transduction. PMID:22768082

Satisfaction with life after burn: A Burn Model System National Database Study.

PubMed

Goverman, J; Mathews, K; Nadler, D; Henderson, E; McMullen, K; Herndon, D; Meyer, W; Fauerbach, J A; Wiechman, S; Carrougher, G; Ryan, C M; Schneider, J C

2016-08-01

While mortality rates after burn are low, physical and psychosocial impairments are common. Clinical research is focusing on reducing morbidity and optimizing quality of life. This study examines self-reported Satisfaction With Life Scale scores in a longitudinal, multicenter cohort of survivors of major burns. Risk factors associated with Satisfaction With Life Scale scores are identified. Data from the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) Burn Model System (BMS) database for burn survivors greater than 9 years of age, from 1994 to 2014, were analyzed. Demographic and medical data were collected on each subject. The primary outcome measures were the individual items and total Satisfaction With Life Scale (SWLS) scores at time of hospital discharge (pre-burn recall period) and 6, 12, and 24 months after burn. The SWLS is a validated 5-item instrument with items rated on a 1-7 Likert scale. The differences in scores over time were determined and scores for burn survivors were also compared to a non-burn, healthy population. Step-wise regression analysis was performed to determine predictors of SWLS scores at different time intervals. The SWLS was completed at time of discharge (1129 patients), 6 months after burn (1231 patients), 12 months after burn (1123 patients), and 24 months after burn (959 patients). There were no statistically significant differences between these groups in terms of medical or injury demographics. The majority of the population was Caucasian (62.9%) and male (72.6%), with a mean TBSA burned of 22.3%. Mean total SWLS scores for burn survivors were unchanged and significantly below that of a non-burn population at all examined time points after burn. Although the mean SWLS score was unchanged over time, a large number of subjects demonstrated improvement or decrement of at least one SWLS category. Gender, TBSA burned, LOS, and school status were associated with SWLS scores at 6 months; scores at 12 months were associated with LOS, school status, and amputation; scores at 24 months were associated with LOS, school status, and drug abuse. In this large, longitudinal, multicenter cohort of burn survivors, satisfaction with life after burn was consistently lower than that of non-burn norms. Furthermore mean SWLS scores did not improve over the two-year follow-up period. This study demonstrates the need for continued efforts to improve patient-centered long term satisfaction with life after burn. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Burned area detection based on Landsat time series in savannas of southern Burkina Faso

NASA Astrophysics Data System (ADS)

Liu, Jinxiu; Heiskanen, Janne; Maeda, Eduardo Eiji; Pellikka, Petri K. E.

2018-02-01

West African savannas are subject to regular fires, which have impacts on vegetation structure, biodiversity and carbon balance. An efficient and accurate mapping of burned area associated with seasonal fires can greatly benefit decision making in land management. Since coarse resolution burned area products cannot meet the accuracy needed for fire management and climate modelling at local scales, the medium resolution Landsat data is a promising alternative for local scale studies. In this study, we developed an algorithm for continuous monitoring of annual burned areas using Landsat time series. The algorithm is based on burned pixel detection using harmonic model fitting with Landsat time series and breakpoint identification in the time series data. This approach was tested in a savanna area in southern Burkina Faso using 281 images acquired between October 2000 and April 2016. An overall accuracy of 79.2% was obtained with balanced omission and commission errors. This represents a significant improvement in comparison with MODIS burned area product (67.6%), which had more omission errors than commission errors, indicating underestimation of the total burned area. By observing the spatial distribution of burned areas, we found that the Landsat based method misclassified cropland and cloud shadows as burned areas due to the similar spectral response, and MODIS burned area product omitted small and fragmented burned areas. The proposed algorithm is flexible and robust against decreased data availability caused by clouds and Landsat 7 missing lines, therefore having a high potential for being applied in other landscapes in future studies.

Impact Assessment of Biomass Burning on Air Quality in Southeast and East Asia During BASE-ASIA

NASA Technical Reports Server (NTRS)

Huang, Kan; Fu, Joshua S.; Hsu, N. Christina; Gao, Yang; Dong, Xinyi; Tsay, Si-Chee; Lam, Yun Fat

2013-01-01

A synergy of numerical simulation, ground-based measurement and satellite observation was applied to evaluate the impact of biomass burning originating from Southeast Asia (SE Asia) within the framework of NASA's 2006 Biomass burning Aerosols in Southeast Asia: Smoke Impact Assessment (BASE-ASIA). Biomass burning emissions in the spring of 2006 peaked in MarcheApril when most intense biomass burning occurred in Myanmar, northern Thailand, Laos, and parts of Vietnam and Cambodia. Model performances were reasonably validated by comparing to both satellite and ground-based observations despite overestimation or underestimation occurring in specific regions due to high uncertainties of biomass burning emission. Chemical tracers of particulate K(+), OC concentrations, and OC/EC ratios showed distinct regional characteristics, suggesting biomass burning and local emission dominated the aerosol chemistry. CMAQ modeled aerosol chemical components were underestimated at most circumstances and the converted AOD values from CMAQ were biased low at about a factor of 2, probably due to the underestimation of biomass emissions. Scenario simulation indicated that the impact of biomass burning to the downwind regions spread over a large area via the Asian spring monsoon, which included Southern China, South China Sea, and Taiwan Strait. Comparison of AERONET aerosol optical properties with simulation at multi-sites clearly demonstrated the biomass burning impact via longrange transport. In the source region, the contribution from biomass burning to AOD was estimated to be over 56%. While in the downwind regions, the contribution was still significant within the range of 26%-62%.

Effect of Lithospermi Radix on Contact Dermatitis Induced by Dinitrofluorobenzene in Mice

PubMed Central

Kim, Han-Na; Kim, Mi-Young; Choi, Chan-Hun; Kim, Byung-Joo; Kim, Kyung-Yoon; Kim, Gye-Yeop; Jeong, Hyun-Woo; Kim, Hyung-Woo

2012-01-01

Objective: The root of Lithospermum erythrorhizon Sieb. et Zucc. (Lithospermi Radix, LR) is a kind of heat clearing and blood cooling medicinal herbs. It can clear away heat and cool the blood, reduce toxins and disperse maculae. LR has long been used as efficacious therapy for inflammation, burns, frostbite and skin diseases such as eczema and psoriasis. Methods: In the present study, we investigate anti-allergic and anti-inflammatory effects of LR by using the 1-fluoro-2, 4- dinitrofluorobenzene (DNFB)-induced contact dermatitis mouse model. Results: Topical application of 10 mg/mL of LR effectively inhibited skin lesions induced by repeated paintings with DNFB. Topical application of LR also inhibited hyperplasia, edema, spongiosis and infiltrations of mononuclear cells. In addition, production levels of total immunoglobulin and IgG1 in serum were decreased by using LR in vivo. Conclusion: These data suggest that LR acts as an antiinflammatory agent, improving skin lesions in CD mice. PMID:25780635

Model of ASTM Flammability Test in Microgravity: Iron Rods

NASA Technical Reports Server (NTRS)

Steinberg, Theodore A; Stoltzfus, Joel M.; Fries, Joseph (Technical Monitor)

2000-01-01

There is extensive qualitative results from burning metallic materials in a NASA/ASTM flammability test system in normal gravity. However, this data was shown to be inconclusive for applications involving oxygen-enriched atmospheres under microgravity conditions by conducting tests using the 2.2-second Lewis Research Center (LeRC) Drop Tower. Data from neither type of test has been reduced to fundamental kinetic and dynamic systems parameters. This paper reports the initial model analysis for burning iron rods under microgravity conditions using data obtained at the LERC tower and modeling the burning system after ignition. Under the conditions of the test the burning mass regresses up the rod to be detached upon deceleration at the end of the drop. The model describes the burning system as a semi-batch, well-mixed reactor with product accumulation only. This model is consistent with the 2.0-second duration of the test. Transient temperature and pressure measurements are made on the chamber volume. The rod solid-liquid interface melting rate is obtained from film records. The model consists of a set of 17 non-linear, first-order differential equations which are solved using MATLAB. This analysis confirms that a first-order rate, in oxygen concentration, is consistent for the iron-oxygen kinetic reaction. An apparent activation energy of 246.8 kJ/mol is consistent for this model.

Deterrent Concentration Measurement with FTIR and Subsequent Ballistic Performance in Medium Caliber Propellant

NASA Technical Reports Server (NTRS)

Furrow, Keith W.; Ritchie, Steve J.; Morris, Amy

2000-01-01

To meet ballistic requirements, medium and small caliber propellants use deterrent coatings to obtain burn rate progressivity. The required amount and distribution of deterrent varies between gun systems, propellant types, and often between lots. Micro Fourier Transform Infrared (FTIR) spectroscopy was used to measure deterrent gradients in RP36 propellants coated with methyl centralite (MC) at different deterrent levels and different processing conditions. The aromatic C-C bonds at 1496 cm(exp -1) wavenumber were used to monitor the deterrent profiles through the grain. Deterrent gradients measured with FTIR spectroscopy were then used to estimate burn rate gradients in the deterred grains. Burn rates were calculated from literature models and from closed bomb data of RP36 containing uniform deterrent concentration. Finally, the burn rate gradients were input into an IBHFG2 model of a 200 cc-closed bomb. The early flame spreading portion of the closed bomb ballistic cycle (0 to 0.2 P/Pmax) was roughly modeled by dividing the charge up into five propellant decks and igniting them at different times in the ballistic cycle. Pressure traces and vivacity curves from closed bomb shots were compared to predictions. In addition to the burn rate gradient, the closed bomb pressure trace was heavily dependent on ignition and flame spread. These two phenomena were not readily distinguishable from one another in deterred grains. The same RP-36 propellant was shot in a 25 mm M793TP round which was again modeled with IBHVG2. Peak pressure and muzzle velocity were accurately modeled when erosive burning effects were empirically factored into the model.

Development of a reactive burn model based upon an explicit visco-plastic pore collapse model

NASA Astrophysics Data System (ADS)

Bouton, Eric; Lefrançois, Alexandre; Belmas, Robert

2015-06-01

Our aim in this study is to develop a reactive burn model based upon a microscopic hot spot model to compute the initiation and shock to detonation of pressed TATB explosives. For the sake of simplicity, the hot spots are supposed to result from the viscoplastic collapse of spherical micro-voids inside the composition. Such a model has been incorporated in a lagrangian hydrodynamic code. In our calculations, 8 different pore diameters, ranging from 100 nm to 1.2 μm, have been taken into account and the porosity associated to each pore size has been deduced from the PBX-9502 void distribution derived from the SAXS. The last ingredient of our model is the burn rate that depends on two main variables. The first one is the shock pressure as proposed by the developers of the CREST model. The second one is the number of effective chemical reaction sites calculated by the microscopic model. Furthermore, the function of the reaction progress variable of the burn rate is similar to that in the SURF model proposed by Menikoff. Our burn rate has been calibrated by using pressure profile, material velocities wave forms obtained with embedded particle velocity gauges and run distance to detonation. The comparison between the numerical and experimental results is really good and sufficient to perform a wide variety of simulations including single, double shock waves and the desensitization phenomenon. In conclusion, future works are described.

Combustion of Nitramine Propellants

DTIC Science & Technology

1983-03-01

through development of a comprehensive analytical model. The ultimate goals are to enable prediction of deflagration rate over a wide pressure range...superior in burn rate prediction , both simple models fail in correlating existing temperature- sensitivity data. (2) In the second part, a...auxiliary condition to enable independent burn rate prediction ; improved melt phase model including decomposition-gas bubbles; model for far-field

Drug discovery in prostate cancer mouse models.

PubMed

Valkenburg, Kenneth C; Pienta, Kenneth J

2015-01-01

The mouse is an important, though imperfect, organism with which to model human disease and to discover and test novel drugs in a preclinical setting. Many experimental strategies have been used to discover new biological and molecular targets in the mouse, with the hopes of translating these discoveries into novel drugs to treat prostate cancer in humans. Modeling prostate cancer in the mouse, however, has been challenging, and often drugs that work in mice have failed in human trials. The authors discuss the similarities and differences between mice and men; the types of mouse models that exist to model prostate cancer; practical questions one must ask when using a mouse as a model; and potential reasons that drugs do not often translate to humans. They also discuss the current value in using mouse models for drug discovery to treat prostate cancer and what needs are still unmet in field. With proper planning and following practical guidelines by the researcher, the mouse is a powerful experimental tool. The field lacks genetically engineered metastatic models, and xenograft models do not allow for the study of the immune system during the metastatic process. There remain several important limitations to discovering and testing novel drugs in mice for eventual human use, but these can often be overcome. Overall, mouse modeling is an essential part of prostate cancer research and drug discovery. Emerging technologies and better and ever-increasing forms of communication are moving the field in a hopeful direction.

Preparation of Partial-Thickness Burn Wounds in Rodents Using a New Experimental Burning Device.

PubMed

Sakamoto, Michiharu; Morimoto, Naoki; Ogino, Shuichi; Jinno, Chizuru; Kawaguchi, Atsushi; Kawai, Katsuya; Suzuki, Shigehiko

2016-06-01

The manual application of hot water or hot metal to an animal's skin surface is often used to prepare burn wound models. However, manual burn creation is subject to human variability. We developed a new device that can control the temperature, time, and pressure of contact to produce precise and reproducible animal burn wounds and investigated the conditions required to prepare various burn wounds using our new device. We prepared burn wounds on F344 rats using 3 contact times 2, 4, and 10 seconds using a stamp heated to 80°C. We observed the wound-healing process macroscopically and histologically and evaluated the burn depth using a laser speckle contrast-imaging device, which evaluated the blood flow of the wound. The changes in the burned area over time, tissue perfusion of the burn wounds, histological evaluation of the burn depth by hematoxylin-eosin and azocarmine and aniline blue staining, and the epithelialization rate (the ratio of the epithelialized area to the wound length) were evaluated on histological sections. Results indicated that the burn wounds prepared with contact times of 2, 4, and 10 seconds corresponded to superficial dermal burns, deep dermal burns, and full-thickness burns, respectively. We demonstrated that partial- and full-thickness burn wounds can be precisely and reproducibly created with our new automated burning device.

3D hydrodynamic simulations of carbon burning in massive stars

NASA Astrophysics Data System (ADS)

Cristini, A.; Meakin, C.; Hirschi, R.; Arnett, D.; Georgy, C.; Viallet, M.; Walkington, I.

2017-10-01

We present the first detailed 3D hydrodynamic implicit large eddy simulations of turbulent convection of carbon burning in massive stars. Simulations begin with radial profiles mapped from a carbon-burning shell within a 15 M⊙ 1D stellar evolution model. We consider models with 1283, 2563, 5123, and 10243 zones. The turbulent flow properties of these carbon-burning simulations are very similar to the oxygen-burning case. We performed a mean field analysis of the kinetic energy budgets within the Reynolds-averaged Navier-Stokes framework. For the upper convective boundary region, we find that the numerical dissipation is insensitive to resolution for linear mesh resolutions above 512 grid points. For the stiffer, more stratified lower boundary, our highest resolution model still shows signs of decreasing sub-grid dissipation suggesting it is not yet numerically converged. We find that the widths of the upper and lower boundaries are roughly 30 per cent and 10 per cent of the local pressure scaleheights, respectively. The shape of the boundaries is significantly different from those used in stellar evolution models. As in past oxygen-shell-burning simulations, we observe entrainment at both boundaries in our carbon-shell-burning simulations. In the large Péclet number regime found in the advanced phases, the entrainment rate is roughly inversely proportional to the bulk Richardson number, RiB (∝RiB-α, 0.5 ≲ α ≲ 1.0). We thus suggest the use of RiB as a means to take into account the results of 3D hydrodynamics simulations in new 1D prescriptions of convective boundary mixing.

Effects of oblique air flow on burning rates of square ethanol pool fires.

PubMed

Tao, Changfa; He, Yaping; Li, Yuan; Wang, Xishi

2013-09-15

The effects of downward airflow on the burning rate and/or burning intensity of square alcohol pool fires for different airflow speeds and directions have been studied experimentally in an inclined wind tunnel. An interesting flame-wrapping phenomenon, caused by impingement of air flow, was observed. The mass burning intensity was found to increase with the airflow speed and the impinging angle. The fuel pan rim temperatures were also measured to study the effect of wind direction and speed on heat transfer from the flame to the fuel source. A model based on heat transfer analysis was developed to correlate the burning intensity with the pan rim characteristic temperature. A good correlation was established between the model results and the experimental results. Copyright © 2013 Elsevier B.V. All rights reserved.

Prediction of Multiple Infections After Severe Burn Trauma: a Prospective Cohort Study

PubMed Central

Yan, Shuangchun; Tsurumi, Amy; Que, Yok-Ai; Ryan, Colleen M.; Bandyopadhaya, Arunava; Morgan, Alexander A.; Flaherty, Patrick J.; Tompkins, Ronald G.; Rahme, Laurence G.

2014-01-01

Objective To develop predictive models for early triage of burn patients based on hyper-susceptibility to repeated infections. Background Infection remains a major cause of mortality and morbidity after severe trauma, demanding new strategies to combat infections. Models for infection prediction are lacking. Methods Secondary analysis of 459 burn patients (≥16 years old) with ≥20% total body surface area burns recruited from six US burn centers. We compared blood transcriptomes with a 180-h cut-off on the injury-to-transcriptome interval of 47 patients (≤1 infection episode) to those of 66 hyper-susceptible patients (multiple [≥2] infection episodes [MIE]). We used LASSO regression to select biomarkers and multivariate logistic regression to built models, accuracy of which were assessed by area under receiver operating characteristic curve (AUROC) and cross-validation. Results Three predictive models were developed covariates of: (1) clinical characteristics; (2) expression profiles of 14 genomic probes; (3) combining (1) and (2). The genomic and clinical models were highly predictive of MIE status (AUROCGenomic = 0.946 [95% CI, 0.906–0.986]); AUROCClinical = 0.864 [CI, 0.794–0.933]; AUROCGenomic/AUROCClinical P = 0.044). Combined model has an increased AUROCCombined of 0.967 (CI, 0.940–0.993) compared to the individual models (AUROCCombined/AUROCClinical P = 0.0069). Hyper-susceptible patients show early alterations in immune-related signaling pathways, epigenetic modulation and chromatin remodeling. Conclusions Early triage of burn patients more susceptible to infections can be made using clinical characteristics and/or genomic signatures. Genomic signature suggests new insights into the pathophysiology of hyper-susceptibility to infection may lead to novel potential therapeutic or prophylactic targets. PMID:24950278

The Fire INventory from NCAR (FINN): a high resolution global model to estimate the emissions from open burning

Treesearch

C. Wiedinmyer; S. K. Akagi; R. J. Yokelson; L. K. Emmons; J. A. Al-Saadi; J. J. Orlando; A. J. Soja

2010-01-01

The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions from open burning of biomass, which includes wildfire, agricultural fires, and prescribed burning and does not include 5 biofuel use and trash burning. Emission factors used in the calculations have been updated with recent data,...

40 CFR 60.3065 - What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Code of Federal Regulations, 2013 CFR

2013-07-01

... close my air curtain incinerator that burns only wood waste, clean lumber, and yard waste and not..., 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3065 What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

40 CFR 60.3065 - What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Code of Federal Regulations, 2012 CFR

2012-07-01

... close my air curtain incinerator that burns only wood waste, clean lumber, and yard waste and not..., 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3065 What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

40 CFR 60.3065 - What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Code of Federal Regulations, 2014 CFR

2014-07-01

... close my air curtain incinerator that burns only wood waste, clean lumber, and yard waste and not..., 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3065 What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

40 CFR 60.3065 - What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Code of Federal Regulations, 2010 CFR

2010-07-01

... close my air curtain incinerator that burns only wood waste, clean lumber, and yard waste and not..., 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3065 What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

40 CFR 60.3065 - What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Code of Federal Regulations, 2011 CFR

2011-07-01

... close my air curtain incinerator that burns only wood waste, clean lumber, and yard waste and not..., 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3065 What must I do if I plan to permanently close my air curtain incinerator that burns only wood...

Determination of Optimal Amikacin Dosing Regimens for Pediatric Patients With Burn Wound Sepsis.

PubMed

Yu, Tian; Stockmann, Chris; Healy, Daniel P; Olson, Jared; Wead, Stephanie; Neely, Alice N; Kagan, Richard J; Spigarelli, Michael G; Sherwin, Catherine M T

2015-01-01

This study aimed to develop optimal amikacin dosing regimens for the empirical treatment of Gram-negative bacterial sepsis in pediatric patients with burn injuries. A pharmacodynamic (PD) target in which the peak concentration (Cmax) is ≥8 times the minimum inhibitory concentration (MIC) (Cmax/MIC ≥ 8) is reflective of optimal bactericidal activity and has been used to predict clinical outcomes. Population pharmacokinetic modeling was performed in NONMEM 7.2 for pediatric patients with and without burn injuries. Amikacin pharmacokinetic parameters were compared between the two groups and multiple dosing regimens were simulated using MATLAB to achieve the PD target in ≥90% of patients with burn injuries. The pharmacokinetic analysis included 282 amikacin concentrations from 70 pediatric patients with burn injuries and 99 concentrations from 32 pediatric patients without burns. A one-compartment model with first-order elimination described amikacin pharmacokinetics well for both groups. Clearance (CL) was significantly higher in patients with burn injuries than in patients without (7.22 vs 5.36 L/h, P < .001). The volume of distribution (V) was also significantly increased in patients with burn injuries (22.7 vs 18.7 L, P < .01). Weight significantly influenced amikacin CL (P < .001) and V (P < .001) for both groups. Model-based simulations showed that a higher amikacin dose (≥25 mg/kg) achieved a Cmax/MIC ≥8 in ≥90% of patients with assumed infections of organisms with an MIC = 8 mg/L. Amikacin pharmacokinetics are altered in patients with burn injuries, including a significant increase in CL and V. In simulations, increased doses (≥25 mg/kg) led to improved PD target attainment rates. Further clinical evaluation of this proposed dosing regimen is warranted to assess clinical and microbiological outcomes in pediatric patients with burn wound sepsis.

Refined Use of Satellite Aerosol Optical Depth Snapshots to Constrain Biomass Burning Emissions in the GOCART Model

NASA Technical Reports Server (NTRS)

Petrenko, Mariya; Kahn, Ralph; Chin, Mian; Limbacher, James

2017-01-01

Simulations of biomass burning (BB) emissions in global chemistry and aerosol transport models depend on external inventories, which provide location and strength of burning aerosol sources. Our previous work (Petrenko et al., 2012) shows that satellite snapshots of aerosol optical depth (AOD) near the emitted smoke plume can be used to constrain model-simulated AOD, and effectively, the assumed source strength. We now refine the satellite-snapshot method and investigate applying simple multiplicative emission correction factors for the widely used Global Fire Emission Database version 3 (GFEDv3) emission inventory can achieve regional-scale consistency between MODIS AOD snapshots and the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model. The model and satellite AOD are compared over a set of more than 900 BB cases observed by the MODIS instrument during the 2004, and 2006-2008 biomass burning seasons. The AOD comparison presented here shows that regional discrepancies between the model and satellite are diverse around the globe yet quite consistent within most ecosystems. Additional analysis of including small fire emission correction shows the complimentary nature of correcting for source strength and adding missing sources, and also indicates that in some regions other factors may be significant in explaining model-satellite discrepancies. This work sets the stage for a larger intercomparison within the Aerosol Inter-comparisons between Observations and Models (AeroCom) multi-model biomass burning experiment. We discuss here some of the other possible factors affecting the remaining discrepancies between model simulations and observations, but await comparisons with other AeroCom models to draw further conclusions.

In vivo burn diagnosis by camera-phone diffuse reflectance laser speckle detection.

PubMed

Ragol, S; Remer, I; Shoham, Y; Hazan, S; Willenz, U; Sinelnikov, I; Dronov, V; Rosenberg, L; Bilenca, A

2016-01-01

Burn diagnosis using laser speckle light typically employs widefield illumination of the burn region to produce two-dimensional speckle patterns from light backscattered from the entire irradiated tissue volume. Analysis of speckle contrast in these time-integrated patterns can then provide information on burn severity. Here, by contrast, we use point illumination to generate diffuse reflectance laser speckle patterns of the burn. By examining spatiotemporal fluctuations in these time-integrated patterns along the radial direction from the incident point beam, we show the ability to distinguish partial-thickness burns in a porcine model in vivo within the first 24 hours post-burn. Furthermore, our findings suggest that time-integrated diffuse reflectance laser speckle can be useful for monitoring burn healing over time post-burn. Unlike conventional diffuse reflectance laser speckle detection systems that utilize scientific or industrial-grade cameras, our system is designed with a camera-phone, demonstrating the potential for burn diagnosis with a simple imager.

In vivo burn diagnosis by camera-phone diffuse reflectance laser speckle detection

PubMed Central

Ragol, S.; Remer, I.; Shoham, Y.; Hazan, S.; Willenz, U.; Sinelnikov, I.; Dronov, V.; Rosenberg, L.; Bilenca, A.

2015-01-01

Burn diagnosis using laser speckle light typically employs widefield illumination of the burn region to produce two-dimensional speckle patterns from light backscattered from the entire irradiated tissue volume. Analysis of speckle contrast in these time-integrated patterns can then provide information on burn severity. Here, by contrast, we use point illumination to generate diffuse reflectance laser speckle patterns of the burn. By examining spatiotemporal fluctuations in these time-integrated patterns along the radial direction from the incident point beam, we show the ability to distinguish partial-thickness burns in a porcine model in vivo within the first 24 hours post-burn. Furthermore, our findings suggest that time-integrated diffuse reflectance laser speckle can be useful for monitoring burn healing over time post-burn. Unlike conventional diffuse reflectance laser speckle detection systems that utilize scientific or industrial-grade cameras, our system is designed with a camera-phone, demonstrating the potential for burn diagnosis with a simple imager. PMID:26819831

Influence of rice straw burning on the levels of polycyclic aromatic hydrocarbons in agricultural county of Taiwan.

PubMed

Lai, Chia-Hsiang; Chen, Kang-Shin; Wang, Hsin-Kai

2009-01-01

Atmospheric particulate and polycyclic aromatic hydrocarbons (PAHs) size distribution were measured at Jhu-Shan (a rural site) and Sin-Gang (a town site) in central Taiwan during the rice straw burning and non-burning periods. The concentrations of total PAHs accounting for a roughly 58% (34%) increment in the concentrations of total PAHs due to rice-straw burning. Combustion-related PAHs during burning periods were 1.54-2.57 times higher than those during non-burning periods. The mass median diameter (MMD) of 0.88-1.21 microm in the particulate phase suggested that rice-straw burning generated the increase in coarse particle number. Chemical mass balance (CMB) receptor model analyses showed that the primary pollution sources at the two sites were similar. However, rice-straw burning emission was specifically identified as a significant source of PAH during burning periods at the two sites. Open burning of rice straws was estimated to contribute approximately 6.3%-24.6% to total atmospheric PAHs at the two sites.

Turbulent Burning Velocities of Two-Component Fuel Mixtures of Methane, Propane and Hydrogen

NASA Astrophysics Data System (ADS)

Kido, Hiroyuki; Nakahara, Masaya; Hashimoto, Jun; Barat, Dilmurat

In order to clarify the turbulent burning velocity of multi-component fuel mixtures, both lean and rich two-component fuel mixtures, in which methane, propane and hydrogen were used as fuels, were prepared while maintaining the laminar burning velocity approximately constant. A distinct difference in the measured turbulent burning velocity at the same turbulence intensity is observed for two-component fuel mixtures having different addition rates of fuel, even the laminar burning velocities are approximately the same. The burning velocities of lean mixtures change almost constantly as the rate of addition changes, whereas the burning velocities of the rich mixtures show no such tendency. This trend can be explained qualitatively based on the mean local burning velocity, which is estimated by taking into account the preferential diffusion effect for each fuel component. In addition, a model of turbulent burning velocity proposed for single-component fuel mixtures may be applied to two-component fuel mixtures by considering the estimated mean local burning velocity of each fuel.

Orthology for comparative genomics in the mouse genome database.

PubMed

Dolan, Mary E; Baldarelli, Richard M; Bello, Susan M; Ni, Li; McAndrews, Monica S; Bult, Carol J; Kadin, James A; Richardson, Joel E; Ringwald, Martin; Eppig, Janan T; Blake, Judith A

2015-08-01

The mouse genome database (MGD) is the model organism database component of the mouse genome informatics system at The Jackson Laboratory. MGD is the international data resource for the laboratory mouse and facilitates the use of mice in the study of human health and disease. Since its beginnings, MGD has included comparative genomics data with a particular focus on human-mouse orthology, an essential component of the use of mouse as a model organism. Over the past 25 years, novel algorithms and addition of orthologs from other model organisms have enriched comparative genomics in MGD data, extending the use of orthology data to support the laboratory mouse as a model of human biology. Here, we describe current comparative data in MGD and review the history and refinement of orthology representation in this resource.

The National Institute on Disability, Independent Living, and Rehabilitation Research Burn Model System: Twenty Years of Contributions to Clinical Service and Research.

PubMed

Goverman, Jeremy; Mathews, Katie; Holavanahalli, Radha K; Vardanian, Andrew; Herndon, David N; Meyer, Walter J; Kowalske, Karen; Fauerbach, Jim; Gibran, Nicole S; Carrougher, Gretchen J; Amtmann, Dagmar; Schneider, Jeffrey C; Ryan, Colleen M

The National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) established the Burn Model System (BMS) in 1993 to improve the lives of burn survivors. The BMS program includes 1) a multicenter longitudinal database describing the functional and psychosocial recovery of burn survivors; 2) site-specific burn-related research; and 3) a knowledge dissemination component directed toward patients and providers. Output from each BMS component was analyzed. Database structure, content, and access procedures are described. Publications using the database were identified and categorized to illustrate the content area of the work. Unused areas of the database were identified for future study. Publications related to site-specific projects were cataloged. The most frequently cited articles are summarized to illustrate the scope of these projects. The effectiveness of dissemination activities was measured by quantifying website hits and information downloads. There were 25 NIDILRR-supported publications that utilized the database. These articles covered topics related to psychological outcomes, functional outcomes, community reintegration, and burn demographics. There were 172 site-specific publications; highly cited articles demonstrate a wide scope of study. For information dissemination, visits to the BMS website quadrupled between 2013 and 2014, with 124,063 downloads of educational material in 2014. The NIDILRR BMS program has played a major role in defining the course of burn recovery, and making that information accessible to the general public. The accumulating information in the database serves as a rich resource to the burn community for future study. The BMS is a model for collaborative research that is multidisciplinary and outcome focused.

Creation of Consistent Burn Wounds: A Rat Model

PubMed Central

Cai, Elijah Zhengyang; Ang, Chuan Han; Raju, Ashvin; Tan, Kong Bing; Hing, Eileen Chor Hoong; Loo, Yihua; Wong, Yong Chiat; Lee, Hanjing; Lim, Jane; Moochhala, Shabbir M; Hauser, Charlotte AE

2014-01-01

Background Burn infliction techniques are poorly described in rat models. An accurate study can only be achieved with wounds that are uniform in size and depth. We describe a simple reproducible method for creating consistent burn wounds in rats. Methods Ten male Sprague-Dawley rats were anesthetized and dorsum shaved. A 100 g cylindrical stainless-steel rod (1 cm diameter) was heated to 100℃ in boiling water. Temperature was monitored using a thermocouple. We performed two consecutive toe-pinch tests on different limbs to assess the depth of sedation. Burn infliction was limited to the loin. The skin was pulled upwards, away from the underlying viscera, creating a flat surface. The rod rested on its own weight for 5, 10, and 20 seconds at three different sites on each rat. Wounds were evaluated for size, morphology and depth. Results Average wound size was 0.9957 cm2 (standard deviation [SD] 0.1845) (n=30). Wounds created with duration of 5 seconds were pale, with an indistinct margin of erythema. Wounds of 10 and 20 seconds were well-defined, uniformly brown with a rim of erythema. Average depths of tissue damage were 1.30 mm (SD 0.424), 2.35 mm (SD 0.071), and 2.60 mm (SD 0.283) for duration of 5, 10, 20 seconds respectively. Burn duration of 5 seconds resulted in full-thickness damage. Burn duration of 10 seconds and 20 seconds resulted in full-thickness damage, involving subjacent skeletal muscle. Conclusions This is a simple reproducible method for creating burn wounds consistent in size and depth in a rat burn model. PMID:25075351

Modeling prescribed fire impacts on local to regional air quality and potential climate effects

EPA Science Inventory

Biomass burning, including wildfires and prescribed burns, are of increasing concern due to the potential impacts on ambient air quality. The direct and indirect radiative forcings associated the particulate matter from biomass burning are also raising questions regarding the pot...

How important is biomass burning in Canada to mercury contamination?

NASA Astrophysics Data System (ADS)

Fraser, Annemarie; Dastoor, Ashu; Ryjkov, Andrei

2018-05-01

Wildfire frequency has increased in past four decades in Canada and is expected to increase in future as a result of climate change (Wotton et al., 2010). Mercury (Hg) emissions from biomass burning are known to be significant; however, the impact of biomass burning on air concentration and deposition fluxes in Canada has not been previously quantified. We use estimates of burned biomass from FINN (Fire INventory from NCAR) and vegetation-specific emission factors (EFs) of mercury to investigate the spatiotemporal variability of Hg emissions in Canada. We use Environment and Climate Change Canada's GEM-MACH-Hg (Global Environmental Multi-scale, Modelling Air quality and Chemistry model, mercury version) to quantify the impact of biomass burning in Canada on spatiotemporal variability of air concentrations and deposition fluxes of mercury in Canada. We use North American gaseous elemental mercury (GEM) observations (2010-2015), GEM-MACH-Hg, and an inversion technique to optimize the EFs for GEM for five vegetation types represented in North American fires to constrain the biomass burning impacts of mercury. The inversion results suggest that EFs representing more vegetation types - specifically peatland - are required. This is currently limited by the sparseness of measurements of Hg from biomass burning plumes. More measurements of Hg concentration in the air, specifically downwind of fires, would improve the inversions. We use three biomass burning Hg emissions scenarios in Canada to conduct three sets of model simulations for 2010-2015: two scenarios where Hg is emitted only as GEM using literature or optimized EFs and a third scenario where Hg is emitted as GEM using literature EFs and particle bound mercury (PBM) emitted using the average GEM/PBM ratio from lab measurements. The three biomass burning emission scenarios represent a range of possible values for the impacts of Hg emissions from biomass burning in Canada on Hg concentration and deposition. We find total biomass burning Hg emissions to be highly variable from year to year and estimate average 2010-2015 total atmospheric biomass burning emissions of Hg in Canada to be between 6 and 14 t during the biomass burning season (i.e. from May to September), which is 3-7 times the mercury emission from anthropogenic sources in Canada for this period. On average, 65 % of the emissions occur in the provinces west of Ontario. We find that while emissions from biomass burning have a small impact on surface air concentrations of GEM averaged over individual provinces/territories, the impact at individual sites can be as high as 95 % during burning events. We estimate average annual mercury deposition from biomass burning in Canada to be between 0.3 and 2.8 t, compared to 0.14 t of mercury deposition from anthropogenic sources during the biomass burning season in Canada. Compared to the biomass burning emissions, the relative impact of fires on mercury deposition is shifted eastward, with on average 54 % percent of the deposition occurring in provinces west of Ontario. While the relative contribution of Canadian biomass burning to the total mercury deposition over each province/territory is no more than 9 % between 2010 and 2015, the local contribution in some locations (including areas downwind of biomass burning) can be as high as 80 % (e.g. northwest of Great Slave Lake in 2014) from May to September. We find that northern Alberta and Saskatchewan, central British Columbia, and the area around Great Slave Lake in the Northwest Territories are at greater risk of mercury contamination from biomass burning. GEM is considered to be the dominant mercury species emitted from biomass burning; however, there remains an uncertainty in the speciation of mercury released from biomass burning. We find that the impact of biomass burning emissions on mercury deposition is significantly affected by the uncertainty in speciation of emitted mercury because PBM is more readily deposited closer to the emission sources than GEM; an addition of ˜ 18 % percent of mercury emission from biomass burning in the form of PBM in the model increases the 6-year average deposition by ˜ 4 times.

Program to Produce Tabulated Data Set Describing NSWC Burn Model for Hydrodynamic Computations

DTIC Science & Technology

1990-09-11

helpful insights of Dr. Raafat Guirguis of the Naval Surface Warfare Center on how the NSWC Burn Model works, and Drs. Schittke and Feisler of...R. Guirguis ) 1 R13 (P. Miller ) 1 R13 (K. Kin) 2 R13 (C. Coffey) 1 R13 (H. Sandusky) 1 R13 (D. Tasker) 1 R13 (E. Lanar) 1 R13 (J. Forbes) 1 R13 (R...NAVSWC TR 90-364 AD-A238 710 PROGRAM TO PRODUCE TABULATED DATA SET DESCRIBING NSWC BURN MODEL FOR HYDRODYNAMIC COMPUTATIONS BY LEWIS C. HUDSON III

Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

PubMed Central

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2015-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. PMID:26387641

Acute and long-term transcriptional responses in sulfur mustard-exposed SKH-1 hairless mouse skin.

PubMed

Vallet, V; Poyot, T; Cléry-Barraud, C; Coulon, D; Sentenac, C; Peinnequin, A; Boudry, I

2012-03-01

Sulfur mustard (HD) ranks among the alkylating chemical warfare agents. Skin contact with HD produces an inflammatory response that evolves into separation at the epidermal-dermal junction conducting to blistering and epidermis necrosis. Up to now, current treatment strategies of HD burns have solely consisted in symptomatic management of skin damage. Therapeutic efficacy studies are still being conducted; classically using appropriate animal skin toxicity models. In order to substantiate the use of SKH-1 hairless mouse as an appropriate model for HD-induced skin lesions, we investigate the time-dependent quantitative gene expression of various selected transcripts associated to the dorsal skin exposure to HD saturated vapors. Using quantitative real time polymerase chain reaction (RT-qPCR), the expression of interleukins (IL-1β and IL-6), tumor necrosis factor (TNF)-α, macrophage inflammatory proteins (MIP)-2α (also called Cxcl2) and MIP-1αR (also called Ccr1), matrix metalloproteases (MMP-9 and MMP-2), laminin γ2 monomer (Lamc2) and keratin (K)1 was determined up to 21 days after HD challenge in order to allow enough time for wound repair to begin. Specific transcript RT-qPCR analysis demonstrated that IL-6, IL-1β, Ccr1, Cxcl2 mRNA levels increased as early as 6 h in HD-exposed skins and remained up-regulated over a 14-day period. Topical application of HD also significantly up-regulated MMP-9, TNF-α, and Lamc2 expression at specific time points. In contrast, MMP-2 mRNA levels remained unaffected by HD over the time-period considered, whereas that long-term study revealed that K1 mRNA level significantly increased only 21 days after HD challenge. Our study hereby provides first-hand evidence to substantiate a long period variation expression in the inflammatory cytokine, MMPs and structural components following cutaneous HD exposure in hairless mouse SKH-1. Our data credit the use of SKH-1 for investigating mechanisms of HD-induced skin toxicity and for the development of pharmacological countermeasures.

Alternative complement pathway activation increases mortality in a model of burn injury in mice.

PubMed Central

Gelfand, J A; Donelan, M; Hawiger, A; Burke, J F

1982-01-01

We have studied the role of the complement system in burn injury in an experimental model in mice. A 25% body surface area, full-thickness scald wound was produced in anesthetized animals. Massive activation of the alternative complement pathway, but not the classical pathway, was seen. This activation was associated with the generation of neutrophil aggregating activity in the plasma, neutrophil aggregates in the lungs, increased pulmonary vascular permeability, and increased lung edema formation. Decomplementation with cobra venom factor (CVF) or genetic C5 deficiency diminished these pathologic changes, and CVF pretreatment substantially reduced burn mortality in the first 24 h. Preliminary data show that human burn patients have a similar pattern of complement activation involving predominantly the alternative pathway, indicating the possible relevance of the murine model to human disease. Images PMID:7174787

In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

NASA Astrophysics Data System (ADS)

Kim, Ki Hean; Pierce, Mark C.; Maguluri, Gopi; Park, B. Hyle; Yoon, Sang June; Lydon, Martha; Sheridan, Robert; de Boer, Johannes F.

2012-06-01

The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm×6 mm×2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.

Spatial frequency domain imaging of burn wounds in a preclinical model of graded burn severity

NASA Astrophysics Data System (ADS)

Nguyen, John Quan; Crouzet, Christian; Mai, Tuan; Riola, Kathleen; Uchitel, Daniel; Liaw, Lih-Huei; Bernal, Nicole; Ponticorvo, Adrien; Choi, Bernard; Durkin, Anthony J.

2013-06-01

Frequent monitoring of early-stage burns is necessary for deciding optimal treatment and management. Both superficial and full thickness burns are relatively easy to diagnose based on clinical observation. In between these two extremes are superficial-partial thickness and deep-partial thickness burns. These burns, while visually similar, differ dramatically in terms of clinical treatment and are known to progress in severity over time. The objective of this study was to determine the potential of spatial frequency domain imaging (SFDI) for noninvasively mapping quantitative changes in chromophore and optical properties that may be an indicative of burn wound severity. A controlled protocol of graded burn severity was developed and applied to 17 rats. SFDI data was acquired at multiple near-infrared wavelengths over a course of 3 h. Burn severity was verified using hematoxylin and eosin histology. From this study, we found that changes in water concentration (edema), deoxygenated hemoglobin concentration, and optical scattering (tissue denaturation) to be statistically significant at differentiating superficial partial-thickness burns from deep-partial thickness burns.

Forward-looking infrared imaging predicts ultimate burn depth in a porcine vertical injury progression model.

PubMed

Miccio, Joseph; Parikh, Shruti; Marinaro, Xavier; Prasad, Atulya; McClain, Steven; Singer, Adam J; Clark, Richard A F

2016-03-01

Current methods of assessing burn depth are limited and are primarily based on visual assessments by burn surgeons. This technique has been shown to have only 60% accuracy and a more accurate, simple, noninvasive method is needed to determine burn wound depth. Forward-looking infrared (FLIR) thermography is both noninvasive and user-friendly with the potential to rapidly assess burn depth. The purpose of this paper is to determine if early changes in burn temperature (first 3 days) can be a predictor of burn depth as assessed by vertical scarring 28 days after injury. While under general anesthesia, 20 burns were created on the backs of two female Yorkshire swine using a 2.5cm×2.5cm×7.5cm, 150g aluminum bar, for a total of 40 burns. FLIR imaging was performed at both early (1, 2 and 3 days) and late (7, 10, 14, 17, 21, 24 and 28 days) time points. Burns were imaged from a height of 12 inches from the skin surface. FLIR ExaminIR(©) software was used to examine the infrared thermographs. One hundred temperature points from burn edge to edge across the center of the burn were collected for each burn at all time points and were exported as a comma-separated values (CSV) file. The CSV file was processed and analyzed using a MATLAB program. The temperature profiles through the center of the burns generated parabola-like curves. The lowest temperature (temperature minimum) and a line midway between the temperature minimum and ambient skin temperature at the burn edges was defined and the area of the curve calculated (the "temperature half-area"). Half-area values 2 days after burn had higher correlations with scar depth than did the minimum temperatures. However, burns that became warmer from 1 day to 2 days after injury had a lower scar depth then burns that became cooler and this trend was best predicted by temperature minima. When data were analyzed as a diagnostic test for sensitivity and specificity using >3mm scarring, i.e. a full-thickness burn, as a clinically relevant criterion standard, temperature minima at 2 days after burn was found to be the most sensitive and specific test. FLIR imaging is a fast and simple tool that has been shown to predict burn wound outcome in a porcine vertical injury progression model. Data showed that more severe burn wounds get cooler between 1 and 2 days after burn. We found four analytic methods of FLIR images that were predictive of burn progression at 1 and 2 days after burn; however, temperature minima 2 days after burn appeared to be the best predictive test for injury progression to a full-thickness burn. Although these results must be validated in clinical studies, FLIR imaging has the potential to aid clinicians in assessing burn severity and thereby assisting in burn wound management. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

South American smoke coverage and flux estimations from the Fire Locating and Modeling of Burning Emissions (FLAMBE') system.

NASA Astrophysics Data System (ADS)

Reid, J. S.; Westphal, D. L.; Christopher, S. A.; Prins, E. M.; Gasso, S.; Reid, E.; Theisen, M.; Schmidt, C. C.; Hunter, J.; Eck, T.

2002-05-01

The Fire Locating and Modeling of Burning Emissions (FLAMBE') project is a joint Navy, NOAA, NASA and university project to integrate satellite products with numerical aerosol models to produce a real time fire and emissions inventory. At the center of the program is the Wildfire Automated Biomass Burning Algorithm (WF ABBA) which provides real-time fire products and the NRL Aerosol Analysis and Prediction System to model smoke transport. In this presentation we give a brief overview of the system and methods, but emphasize new estimations of smoke coverage and emission fluxes from the South American continent. Temporal and smoke patterns compare reasonably well with AERONET and MODIS aerosol optical depth products for the 2000 and 2001 fire seasons. Fluxes are computed by relating NAAPS output fields and MODIS optical depth maps with modeled wind fields. Smoke emissions and transport fluxes out of the continent can then be estimated by perturbing the modeled emissions to gain agreement with the satellite and wind products. Regional smoke emissions are also presented for grass and forest burning.

A simple model for the dependence on local detonation speed of the product entropy

NASA Astrophysics Data System (ADS)

Hetherington, David C.; Whitworth, Nicholas J.

2012-03-01

The generation of a burn time field as a pre-processing step ahead of a hydrocode calculation has been mostly upgraded in the explosives modelling community from the historical model of singlespeed programmed burn to DSD/WBL (Detonation Shock Dynamics / Whitham Bdzil Lambourn). The problem with this advance is that the previously conventional approach to the hydrodynamic stage of the model results in the entropy of the detonation products (s) having the wrong correlation with detonation speed (D). Instead of being higher where D is lower, the conventional method leads to s being lower where D is lower, resulting in a completely fictitious enhancement of available energy where the burn is degraded! A technique is described which removes this deficiency of the historical model when used with a DSD-generated burn time field. By treating the conventional JWL equation as a semi-empirical expression for the local expansion isentrope, and constraining the local parameter set for consistency with D, it is possible to obtain the two desirable outcomes that the model of the detonation wave is internally consistent, and s is realistically correlated with D.

A Simple Model for the Dependence on Local Detonation Speed (D) of the Product Entropy (S)

NASA Astrophysics Data System (ADS)

Hetherington, David

2011-06-01

The generation of a burn time field as a pre-processing step ahead of a hydrocode calculation has been mostly upgraded in the explosives modelling community from the historical model of single-speed programmed burn to DSD. However, with this advance has come the problem that the previously conventional approach to the hydrodynamic stage of the model results in S having the wrong correlation with D. Instead of being higher where the detonation speed is lower, i.e. where reaction occurs at lower compression, the conventional method leads to S being lower where D is lower, resulting in a completely fictitious enhancement of available energy where the burn is degraded! A technique is described which removes this deficiency of the historical model when used with a DSD-generated burn time field. By treating the conventional JWL equation as a semi-empirical expression for the local expansion isentrope, and constraining the local parameter set for consistency with D, it is possible to obtain the two desirable outcomes that the model of the detonation wave is internally consistent, and S is realistically correlated with D.

The First 3D Simulations of Carbon Burning in a Massive Star

NASA Astrophysics Data System (ADS)

Cristini, A.; Meakin, C.; Hirschi, R.; Arnett, D.; Georgy, C.; Viallet, M.

2017-11-01

We present the first detailed three-dimensional hydrodynamic implicit large eddy simulations of turbulent convection for carbon burning. The simulations start with an initial radial profile mapped from a carbon burning shell within a 15 M⊙ stellar evolution model. We considered 4 resolutions from 1283 to 10243 zones. These simulations confirm that convective boundary mixing (CBM) occurs via turbulent entrainment as in the case of oxygen burning. The expansion of the boundary into the surrounding stable region and the entrainment rate are smaller at the bottom boundary because it is stiffer than the upper boundary. The results of this and similar studies call for improved CBM prescriptions in 1D stellar evolution models.

Two-year follow-up of outcomes related to scarring and distress in children with severe burns.

PubMed

Wurzer, Paul; Forbes, Abigail A; Hundeshagen, Gabriel; Andersen, Clark R; Epperson, Kathryn M; Meyer, Walter J; Kamolz, Lars P; Branski, Ludwik K; Suman, Oscar E; Herndon, David N; Finnerty, Celeste C

2017-08-01

We assessed the perception of scarring and distress by pediatric burn survivors with burns covering more than one-third of total body surface area (TBSA) for up to 2 years post-burn. Children with severe burns were admitted to our hospital between 2004 and 2012, and consented to this IRB-approved-study. Subjects completed at least one Scars Problems and/or Distress questionnaire between discharge and 24 months post burn. Outcomes were modeled with generalized estimating equations or using mixed linear models. Significance was accepted at p < 0.01. Responses of 167 children with a mean age of 7 ± 5 years and burns covering an average 54 ± 14% of TBSA were analyzed. Significant improvements over the 2-year period were seen in reduction of pain, itching, sleeping disturbance, tightness, range of motion, and strength (p < 0.01). There was a significantly increased persistent desire to hide the scarred body areas over time (p < 0.01). The perception of mouth scarring, inability to portray accurate facial expressions, and skin coloration did not improve over the follow-up period. According to self-assessment questionnaires, severely burned children exhibit significant improvements in their overall perception of scarring and distress. However, these patients remain self-conscious with respect to their body image even 2 years after burn injury. Implications for Rehabilitation According to self-assessment questionnaires, severely burned children perceive significant improvements in scarring and distress during the first 2 years post burn. Significant improvements were seen in reduction of pain, itching, sleeping disturbances, tightness, range of motion, and strength (p < 0.01). Burn care providers should improve the treatment of burns surrounding the mouth that with result in scarring, and develop strategies to prevent skin discoloration. Careful evaluation of pain and sleeping disorders during the first year post burn are warranted to improve the patient rehabilitation. Overall, significantly more female patients expressed a persistent desire to hide their scarred body areas. The rehabilitation team should provide access to wigs or other aids to pediatric burn survivors to address these needs.

Benchmarks for multidimensional recovery after burn injury in young adults: the development, validation, and testing of the American Burn Association/Shriners Hospitals for Children young adult burn outcome questionnaire.

PubMed

Ryan, Colleen M; Schneider, Jeffrey C; Kazis, Lewis E; Lee, Austin; Li, Nien-Chen; Hinson, Michelle; Bauk, Helena; Peck, Michael; Meyer, Walter J; Palmieri, Tina; Pidcock, Frank S; Reilly, Debra; Tompkins, Ronald G

2013-01-01

Although data exist on burn survival, there are little data on long-term burn recovery. Patient-centered health outcomes are useful in monitoring and predicting recovery and evaluating treatments. An outcome questionnaire for young adult burn survivors was developed and tested. This 5-year (2003-2008) prospective, controlled, multicenter study included burned and nonburned adults ages 19 to 30 years. The Young Adult Burn Outcome Questionnaires were completed at initial contact, 10 days, and 6 and 12 months. Factor analysis established construct validity. Reliability assessments used Cronbach α and test-retest. Recovery patterns were investigated using generalized linear models, with generalized estimating equations using mixed models and random effects. Burned (n = 153) and nonburned subjects (n = 112) completed 620 questionnaires (47 items). Time from injury to first questionnaire administration was 157 ± 36 days (mean ± SEM). Factor analysis included 15 factors: Physical Function, Fine Motor Function, Pain, Itch, Social Function Limited by Physical Function, Perceived Appearance, Social Function Limited by Appearance, Sexual Function, Emotion, Family Function, Family Concern, Satisfaction With Symptom Relief, Satisfaction With Role, Work Reintegration, and Religion. Cronbach α ranged from 0.72 to 0.92, with 11 scales >0.8. Test-retest reliability ranged from 0.29 to 0.94, suggesting changes in underlying health status after burns. Recovery curves in five domains, Itch, Perceived Appearance, Social Function Limited by Appearance, Family Concern, and Satisfaction with Symptom Relief, remained below the reference group at 24 months. The Young Adult Burn Outcome Questionnaire is a reliable and valid instrument for multidimensional functional outcomes assessment. Recovery in some domains was incomplete.

What could have caused pre-industrial biomass burning emissions to exceed current rates?

NASA Astrophysics Data System (ADS)

van der Werf, G. R.; Peters, W.; van Leeuwen, T. T.; Giglio, L.

2012-08-01

Recent studies based on trace gas mixing ratios in ice cores and charcoal data indicate that biomass burning emissions over the past millennium exceeded contemporary emissions by up to a factor of 4 for certain time periods. This is surprising because various sources of biomass burning are linked with population density, which has increased over the past centuries. Here we have analyzed how emissions from several biomass burning sources could have fluctuated to yield emissions that are in correspondence with recent results based on ice core mixing ratios of carbon monoxide (CO) and its isotopic signature measured at South Pole station (SPO). Based on estimates of contemporary fire emissions and the TM5 chemical transport model, we found that CO mixing ratios at SPO are more sensitive to emissions from South America and Australia than from Africa, and are relatively insensitive to emissions from the Northern Hemisphere. We then explored how various biomass burning sources may have varied over the past centuries and what the resulting emissions and corresponding CO mixing ratio at SPO would be, using population density variations to reconstruct sources driven by humans (e.g. fuelwood burning) and a new model to relate savanna emissions to changes in fire return times. We found that to match the observed ice core CO data all savannas in the Southern Hemisphere had to burn annually, or bi-annually in combination with deforestation and slash and burn agriculture matching current levels despite much lower population densities and lack of machinery to aid the deforestation process. While possible, these scenarios are unlikely and in conflict with current literature. However, we do show the large potential for increased emissions from savannas in a pre-industrial world. This is mainly because in the past, fuel beds were probably less fragmented compared to the current situation; we show that the majority of savannas have not burned in the past 10 yr, even in Africa which is considered "the burning continent". Our new modelling results, together with existing literature, indicate that no definitive conclusions can be drawn about unprecedentedly high or low biomass burning rates from current data analyses.

Interactive effects of acupuncture on pain and distress in major burns: An experiment with rats.

PubMed

Abali, Ayse Ebru; Cabioglu, Tugrul; Ozdemir, Handan; Haberal, Mehmet

2015-06-01

This study sought to investigate the interactive effects of acupuncture on pain and distress and the local progress in the burn wound in an experimental major burn model. Forty-eight male Sprague-Dawley rats were divided into six groups: S group (sham/observation during 7 days after injury); SA group (sham/acupuncture/observation during 7 days after injury); B1 group (burns/observation during 1h after injury); BA1 group (burns/acupuncture/observation during 1 h after injury); B7 group (burns/observation during 7 days after injury); and BA7 group (burns/acupuncture/observation during 7 days after injury). Pain and distress scores were evaluated throughout the study. The amounts of neutrophils and mononuclear cells were evaluated semiquantitatively, and the number of microvessels was evaluated quantitatively. Our data indicated that the average pain score of BA7 group was significantly lower than the other study groups. Histopathologic investigations indicate that the amounts of neutrophil and mononuclear cell and numbers of microvessels in the unburned skin were higher in acupuncture-applied groups. The number of microvessels in burn wounds of BA7 group was significantly higher than that of the other groups. Our data suggest that acupuncture provides low pain and distress scores in experimental rat model, and it contributes to wound healing with an enhanced angiogenesis during the acute phase of burns. Future clinical and experimental studies should be conducted to discern the benefits from acupuncture in pain management of burn patients. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Extracorporeal Shock Wave Therapy Suppresses the Early Proinflammatory Immune Response to a Severe Cutaneous Burn Injury

DTIC Science & Technology

2009-02-01

Burn wound model Mice were anaesthetised using isoflurane inha- lation. After shaving the dorsum, the exposed skin was washed gently with room...Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn injury* Thomas A Davis, Alexander...S, Peoples GE, Tadaki D, Elster EA. Extracorporeal shock wave therapy suppresses the early proinflammatory immune response to a severe cutaneous burn

Optimization of Equation of State and Burn Model Parameters for Explosives

NASA Astrophysics Data System (ADS)

Bergh, Magnus; Wedberg, Rasmus; Lundgren, Jonas

2017-06-01

A reactive burn model implemented in a multi-dimensional hydrocode can be a powerful tool for predicting non-ideal effects as well as initiation phenomena in explosives. Calibration against experiment is, however, critical and non-trivial. Here, a procedure is presented for calibrating the Ignition and Growth Model utilizing hydrocode simulation in conjunction with the optimization program LS-OPT. The model is applied to the explosive PBXN-109. First, a cylinder expansion test is presented together with a new automatic routine for product equation of state calibration. Secondly, rate stick tests and instrumented gap tests are presented. Data from these experiments are used to calibrate burn model parameters. Finally, we discuss the applicability and development of this optimization routine.

Potential Use of Dimethyl Sulfoxide in Treatment of Infections Caused by Pseudomonas aeruginosa.

PubMed

Guo, Qiao; Wu, Qiaolian; Bai, Dangdang; Liu, Yang; Chen, Lin; Jin, Sheng; Wu, Yuting; Duan, Kangmin

2016-12-01

Dimethyl sulfoxide (DMSO) is commonly used as a solvent to dissolve water-insoluble drugs or other test samples in both in vivo and in vitro experiments. It was observed during our experiment that DMSO at noninhibitory concentrations could significantly inhibit pyocyanin production in the human pathogen Pseudomonas aeruginosa Pyocyanin is an important pathogenic factor whose production is controlled by a cell density-dependent quorum-sensing (QS) system. Investigation of the effect of DMSO on QS showed that DMSO has significant QS antagonistic activities and concentrations of DMSO in the micromolar range attenuated a battery of QS-controlled virulence factors, including rhamnolipid, elastase, and LasA protease production and biofilm formation. Further study indicated that DMSO inhibition of biofilm formation and pyocyanin production was attained by reducing the level of production of an autoinducer molecule of the rhl QS system, N-butanoyl-l-homoserine lactone (C 4 -HSL). In a mouse model of a burn wound infection with P. aeruginosa, treatment with DMSO significantly decreased mouse mortality compared with that for mice in the control group. The capacity of DMSO to attenuate the pathogenicity of P. aeruginosa points to the potential use of DMSO as an antipathogenic agent for the treatment of P. aeruginosa infection. As a commonly used solvent, however, DMSO's impact on bacterial virulence calls for cautionary attention in its usage in biological, medicinal, and clinical studies. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Meteorological Controls on Biomass Burning During Santa Ana Events in Southern California

NASA Technical Reports Server (NTRS)

Veraverbeke, Sander; Capps, Scott; Hook, Simon J.; Randerson, James T.; Jin, Yufang; Hall, Alex

2013-01-01

Fires occurring during Santa Ana (SA) events in southern California are driven by extreme fire weather characterized by high temperatures, low humidities, and high wind speeds. We studied the controls on burned area and carbon emissions during two intensive SA burning periods in 2003 and 2007. We therefore used remote sensing data in parallel with fire weather simulations of the Weather and Regional Forecast model. Total carbon emissions were approximately 1800 gigagrams in 2003 and 900 gigagrams in 2007, based on a daily burned area and a fire emission model that accounted for spatial variability in fuel loads and combustion completeness. On a regional scale, relatively strong positive correlations were found between the daily Fosberg fire weather index and burned area/emissions (probability is less than 0.01). Our analysis provides a quantitative assessment of relationships between fire activity and weather during severe SA fires in southern California.

Modeling study of biomass burning plumes and their impact on urban air quality; a case study of Santiago de Chile

NASA Astrophysics Data System (ADS)

Cuchiara, Gustavo C.; Rappenglück, Bernhard; Angelica Rubio, Maria; Lissi, Eduardo; Gramsch, Ernesto; Garreaud, Rene D.

2017-04-01

Wildfires are a significant direct source of atmospheric pollutants; on a global scale biomass burning is believed to be the largest source of primary fine particles in the atmosphere and the second largest source of trace gases after anthropogenic emission sources. During the summer of 2014, an intense forest and dry pasture wildfire occurred nearby the city of Santiago de Chile. The biomass-burning plume was transported towards the metropolitan area of Santiago and exacerbated the air quality in this region. In this study, we investigated this wildfire event using a forward plume-rise and a chemistry (WRF/Chem) simulation. These data sets provided an opportunity to validate a regional air-quality simulation over Santiago, and a unique case to assess the performance of biomass burning plume modeling in complex topography and validated against an established air quality network. The results from both meteorological and air quality models provide insights about the transport of biomass-burning plumes from the wildfire region towards the metropolitan region of Santiago de Chile. We studied a seven-day period between January 01-07, 2014, and the impact of biomass burning plume emissions estimated by Fire Inventory from NCAR version 1 (FINNv1) on the air quality of Santiago de Chile.

Computational study of single-expansion-ramp nozzles with external burning

NASA Astrophysics Data System (ADS)

Yungster, Shaye; Trefny, Charles J.

1992-04-01

A computational investigation of the effects of external burning on the performance of single expansion ramp nozzles (SERN) operating at transonic speeds is presented. The study focuses on the effects of external heat addition and introduces a simplified injection and mixing model based on a control volume analysis. This simplified model permits parametric and scaling studies that would have been impossible to conduct with a detailed CFD analysis. The CFD model is validated by comparing the computed pressure distribution and thrust forces, for several nozzle configurations, with experimental data. Specific impulse calculations are also presented which indicate that external burning performance can be superior to other methods of thrust augmentation at transonic speeds. The effects of injection fuel pressure and nozzle pressure ratio on the performance of SERN nozzles with external burning are described. The results show trends similar to those reported in the experimental study, and provide additional information that complements the experimental data, improving our understanding of external burning flowfields. A study of the effect of scale is also presented. The results indicate that combustion kinetics do not make the flowfield sensitive to scale.

Computational study of single-expansion-ramp nozzles with external burning

NASA Technical Reports Server (NTRS)

Yungster, Shaye; Trefny, Charles J.

1992-01-01

A computational investigation of the effects of external burning on the performance of single expansion ramp nozzles (SERN) operating at transonic speeds is presented. The study focuses on the effects of external heat addition and introduces a simplified injection and mixing model based on a control volume analysis. This simplified model permits parametric and scaling studies that would have been impossible to conduct with a detailed CFD analysis. The CFD model is validated by comparing the computed pressure distribution and thrust forces, for several nozzle configurations, with experimental data. Specific impulse calculations are also presented which indicate that external burning performance can be superior to other methods of thrust augmentation at transonic speeds. The effects of injection fuel pressure and nozzle pressure ratio on the performance of SERN nozzles with external burning are described. The results show trends similar to those reported in the experimental study, and provide additional information that complements the experimental data, improving our understanding of external burning flowfields. A study of the effect of scale is also presented. The results indicate that combustion kinetics do not make the flowfield sensitive to scale.

Genome-wide expression profiling of five mouse models identifies similarities and differences with human psoriasis.

PubMed

Swindell, William R; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P; Voorhees, John J; Elder, James T; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P; DiGiovanni, John; Pittelkow, Mark R; Ward, Nicole L; Gudjonsson, Johann E

2011-04-04

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis.

Topically applied metal chelator reduces thermal injury progression in a rat model of brass comb burn.

PubMed

Wang, Cheng Z; Ayadi, Amina El; Goswamy, Juhi; Finnerty, Celeste C; Mifflin, Randy; Sousse, Linda; Enkhbaatar, Perenlei; Papaconstantinou, John; Herndon, David N; Ansari, Naseem H

2015-12-01

Oxidative stress may be involved in the cellular damage and tissue destruction as burn wounds continues to progress after abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of Livionex formulation (LF) lotion, that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent or reduce burns. We used an established brass comb burn model with some modifications. Topical application of LF lotion was started 5 min post-burn, and repeated every 8 h for 3 consecutive days. Rats were euthanized and skin harvested for histochemistry and immunohistochemistry. Formation of protein adducts of 4-hydroxynonenal (HNE), malonadialdehyde (MDA) and acrolein (ACR) and expression of aldehyde dehydrogenase (ALDH) isozymes, ALDH1 and ALDH2 were assessed. LF lotion-treated burn sites and interspaces showed mild morphological improvement compared to untreated burn sites. Furthermore, the lotion significantly decreased the immunostaining of lipid aldehyde-protein adducts including protein -HNE, -MDA and -ACR adducts, and restored the expression of aldehyde dehydrogenase isozymes in the unburned interspaces. This data, for the first time, demonstrates that a topically applied EDTA-containing lotion protects burns progression with a concomitant decrease in the accumulation of reactive lipid aldehydes and protection of aldehyde dehydrogenase isozymes. Present studies are suggestive of therapeutic intervention of burns by this novel lotion. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

Topically Applied Metal Chelator Reduces Thermal Injury Progression in a Rat Model of Brass Comb Burn

PubMed Central

Wang, Cheng Z.; El Ayadi, Amina; Goswamy, Juhi; Finnerty, Celeste C.; Mifflin, Randy; Sousse, Linda; Enkhbaatar, Perenlei; Papaconstantinou, John; Herndon, David N.; Ansari, Naseem H.

2016-01-01

Oxidative stress may be involved in the cellular damage and tissue destruction as burn wounds continues to progress after abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of Livionex formulation (LF) lotion, that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent or reduce burn injury. Methods We used an established brass comb burn model with some modifications. Topical application of LF lotion was started 5 minutes post-burn, and repeated every 8 hours for 3 consecutive days. Rats were euthanized and skin harvested for histochemistry and immunohistochemistry. Formation of protein adducts of 4-hydroxynonenal (HNE), malonadialdehyde (MDA) and acrolein (ACR) and expression of aldehyde dehydrogenase (ALDH) isozymes, ALDH1 and ALDH2 were assessed. Results LF lotion-treated burn sites and interspaces showed mild morphological improvement compared to untreated burn sites. Furthermore, the lotion significantly decreased the immunostaining of lipid aldehyde-protein adducts including protein -HNE, -MDA and -ACR adducts, and restored the expression of aldehyde dehydrogenase isozymes in the unburned interspaces. Conclusion This data, for the first time, demonstrates that a topically applied EDTA-containing lotion protects burn injury progression with a concomitant decrease in the accumulation of reactive lipid aldehydes and protection of aldehyde dehydrogenase isozymes. Present studies are suggestive of therapeutic intervention of burn injury by this novel lotion. PMID:26392023

Smoke inhalation increases intensive care requirements and morbidity in paediatric burns.

PubMed

Tan, Alethea; Smailes, Sarah; Friebel, Thessa; Magdum, Ashish; Frew, Quentin; El-Muttardi, Naguib; Dziewulski, Peter

2016-08-01

Burn survival has improved with advancements in fluid resuscitation, surgical wound management, wound dressings, access to antibiotics and nutritional support for burn patients. Despite these advancements, the presence of smoke inhalation injury in addition to a cutaneous burn still significantly increases morbidity and mortality. The pathophysiology of smoke inhalation has been well studied in animal models. Translation of this knowledge into effectiveness of clinical management and correlation with patient outcomes including the paediatric population, is still limited. We retrospectively reviewed our experience of 13 years of paediatric burns admitted to a regional burn's intensive care unit. We compared critical care requirements and patient outcomes between those with cutaneous burns only and those with concurrent smoke inhalation injury. Smoke inhalation increases critical care requirements and mortality in the paediatric burn population. Therefore, early critical care input in the management of these patients is advised. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Preliminary evidence of early bone resorption in a sheep model of acute burn injury: an observational study.

PubMed

Klein, Gordon L; Xie, Yixia; Qin, Yi-Xian; Lin, Liangjun; Hu, Minyi; Enkhbaatar, Perenlei; Bonewald, Lynda F

2014-03-01

Treatment with bisphosphonates within the first 10 days of severe burn injury completely prevents bone loss. We therefore postulated that bone resorption occurs early post burn and is the primary explanation for acute bone loss in these patients. Our objective was to assess bone for histological and biomechanical evidence of early resorption post burn. We designed a randomized controlled study utilizing a sheep model of burn injury. Three sheep received a 40 % total body surface area burn under isoflurane anesthesia, and three other sheep received cotton-smoke inhalation and served as control. Burned sheep were killed 5 days post procedure and controls were killed 2 days post procedure. Backscatter scanning electron microscopy was performed on iliac crests obtained immediately postmortem along with quantitative histomorphometry and compression testing to determine bone strength (Young's modulus). Blood ionized Ca was also determined in the first 24 h post procedure as was urinary CTx. Three of three sheep killed at 5 days had evidence of scalloping of the bone surface, an effect of bone resorption, whereas none of the three sheep killed at 2 days post procedure had scalloping. One of the three burned sheep killed at 5 days showed quantitative doubling of the eroded surface and halving of the bone volume compared to sham controls. Mean values of Young's modulus were approximately one third lower in the burned sheep killed at 5 days compared to controls, p = 0.08 by unpaired t test, suggesting weaker bone. These data suggest early post-burn bone resorption. Urine CTx normalized to creatinine did not differ between groups at 24 h post procedure because the large amounts of fluids received by the burned sheep may have diluted urine creatinine and CTx and because the urine volume produced by the burned sheep was threefold that of the controls. We calculated 24 h urinary CTx excretion, and with this calculation CTx excretion/24 h in the burned sheep was nearly twice that of the controls. Moreover, whole blood ionized Ca measured at 3- to 6-h intervals over the first 24 h in both burn and control sheep showed a 6 % reduction versus baseline in the burned sheep with <1 % reduction in the control animals. This sheep model was previously used to demonstrate upregulation of the parathyroid calcium-sensing receptor within the timeframe of the present study. Because both early bone resorption, supported by this study, and calcium-sensing receptor upregulation, consistent with the observed reduction in blood ionized Ca, are mediated by proinflammatory cytokines that are present as part of the post-burn systemic inflammatory response, we may postulate that post-burn upregulation of the parathyroid calcium-sensing receptor may be an adaptive response to clear the blood of excess calcium liberated by cytokine-mediated bone resorption.

Comparing the Global Charcoal Database with Burned Area Trends from an Offline Fire Model Driven by the NCAR Last Millennium Ensemble

NASA Astrophysics Data System (ADS)

Schaefer, A.; Magi, B. I.; Marlon, J. R.; Bartlein, P. J.

2017-12-01

This study uses an offline fire model driven by output from the NCAR Community Earth System Model Last Millennium Ensemble (LME) to evaluate how climate, ecological, and human factors contributed to burned area over the past millennium, and uses the Global Charcoal Database (GCD) record of fire activity as a constraint. The offline fire model is similar to the fire module within the NCAR Community Land Model. The LME experiment includes 13 simulations of the Earth system from 850 CE through 2005 CE, and the fire model simulates burned area using LME climate and vegetation with imposed land use and land cover change. The fire model trends are compared to GCD records of charcoal accumulation rates derived from sediment cores. The comparisons are a way to assess the skill of the fire model, but also set up a methodology to directly test hypotheses of the main drivers of fire patterns over the past millennium. The focus is on regions selected from the GCD with high data density, and that have lake sediment cores that best capture the last millennium. Preliminary results are based on a fire model which excludes burning cropland and pasture land cover types, but this allows some assessment of how climate variability is captured by the fire model. Generally, there is good agreement between modeled burned area trends and fire trends from GCD for many regions of interest, suggesting the strength of climate variability as a control. At the global scale, trends and features are similar from 850 to 1700, which includes the Medieval Climate Anomaly and the Little Ice Age. After 1700, the trends significantly deviate, which may be due to non-cultivated land being converted to cultivated. In key regions of high data density in the GCD such as the Western USA, the trends agree from 850 to 1200 but diverge from 1200 to 1300. From 1300 to 1800, the trends show good agreement again. Implementing processes to include burning cultivated land within the fire model is anticipated to improve the agreement, but also to test the sensitivity of models to different drivers of fire.

Optimal Timing for Early Excision in a Deep Partial Thickness Porcine Burn Model.

PubMed

Toussaint, Jimmy; Chung, Won Taek; Mc Clain, Steve; Raut, Vivek; Singer, Adam J

Many deep partial thickness burns require more than 3 weeks to heal resulting in disfiguring and dysfunctional scarring. Early excision of the eschar has been shown to improve outcomes in deep burns; however, the optimal timing of the excision remains controversial. We compared wound healing and scarring of deep partial thickness burns that were excised at different time points in a porcine model. Deep partial thickness burns (2.5 by 2.5 cm each) were created on the backs of six anesthetized pigs using a previously validated model. The burns were randomly assigned to excision at days 2, 4, or 7 using an electric dermatome. Full thickness 4-mm punch biopsies were obtained at several time points for determination of re-epithelialization and at day 28 for determination of scar depth. Digital imaging was used to calculate percentage wound contraction at day 28. There were no statistically significant differences in wound re-epithelialization at any of the studied time points. Scar depth and percentage wound contraction were also similar among the wounds excised at 2, 4, and 7 days (4.4 ± 1.1 mm vs 3.9 ± 1.1 mm vs 4.1 ± 1.2 mm and 52.9 ± 17.9% vs 52.6 ± 15.6% vs 52.5 ± 13.8%, respectively). Timing of eschar excision (at 2, 4, or 7 days) does not affect the rates of re-epithelialization and scarring in a deep partial thickness porcine burn model. Timing of eschar excision may not change outcomes if performed within the first 2 to 7 days after injury.

Legacy effects of wildfire on stream thermal regimes and rainbow trout ecology: an integrated analysis of observation and individual-based models

USGS Publications Warehouse

Rosenberger, Amanda E.; Dunham, Jason B.; Neuswanger, Jason R.; Railsback, Steven F.

2015-01-01

Management of aquatic resources in fire-prone areas requires understanding of fish species’ responses to wildfire and of the intermediate- and long-term consequences of these disturbances. We examined Rainbow Trout populations in 9 headwater streams 10 y after a major wildfire: 3 with no history of severe wildfire in the watershed (unburned), 3 in severely burned watersheds (burned), and 3 in severely burned watersheds subjected to immediate events that scoured the stream channel and eliminated streamside vegetation (burned and reorganized). Results of a previous study of this system suggested the primary lasting effects of this wildfire history on headwater stream habitat were differences in canopy cover and solar radiation, which led to higher summer stream temperatures. Nevertheless, trout were present throughout streams in burned watersheds. Older age classes were least abundant in streams draining watersheds with a burned and reorganized history, and individuals >1 y old were most abundant in streams draining watersheds with an unburned history. Burned history corresponded with fast growth, low lipid content, and early maturity of Rainbow Trout. We used an individual-based model of Rainbow Trout growth and demographic patterns to determine if temperature interactions with bioenergetics and competition among individuals could lead to observed phenotypic and ecological differences among populations in the absence of other plausible mechanisms. Modeling suggested that moderate warming associated with wildfire and channel disturbance history leads to faster individual growth, which exacerbates competition for limited food, leading to decreases in population densities. The inferred mechanisms from this modeling exercise suggest the transferability of ecological patterns to a variety of temperature-warming scenarios.

Local and global pyrogeographic evidence that indigenous fire management creates pyrodiversity.

PubMed

Trauernicht, Clay; Brook, Barry W; Murphy, Brett P; Williamson, Grant J; Bowman, David M J S

2015-05-01

Despite the challenges wildland fire poses to contemporary resource management, many fire-prone ecosystems have adapted over centuries to millennia to intentional landscape burning by people to maintain resources. We combine fieldwork, modeling, and a literature survey to examine the extent and mechanism by which anthropogenic burning alters the spatial grain of habitat mosaics in fire-prone ecosystems. We survey the distribution of Callitris intratropica, a conifer requiring long fire-free intervals for establishment, as an indicator of long-unburned habitat availability under Aboriginal burning in the savannas of Arnhem Land. We then use cellular automata to simulate the effects of burning identical proportions of the landscape under different fire sizes on the emergent patterns of habitat heterogeneity. Finally, we examine the global extent of intentional burning and diversity of objectives using the scientific literature. The current distribution of Callitris across multiple field sites suggested long-unburnt patches are common and occur at fine scales (<0.5 ha), while modeling revealed smaller, patchy disturbances maximize patch age diversity, creating a favorable habitat matrix for Callitris. The literature search provided evidence for intentional landscape burning across multiple ecosystems on six continents, with the number of identified objectives ranging from two to thirteen per study. The fieldwork and modeling results imply that the occurrence of long-unburnt habitat in fire-prone ecosystems may be an emergent property of patch scaling under fire regimes dominated by smaller fires. These findings provide a model for understanding how anthropogenic burning alters spatial and temporal aspects of habitat heterogeneity, which, as the literature survey strongly suggests, warrant consideration across a diversity of geographies and cultures. Our results clarify how traditional fire management shapes fire-prone ecosystems, which despite diverse objectives, has allowed human societies to cope with fire as a recurrent disturbance.

Local and global pyrogeographic evidence that indigenous fire management creates pyrodiversity

PubMed Central

Trauernicht, Clay; Brook, Barry W; Murphy, Brett P; Williamson, Grant J; Bowman, David M J S

2015-01-01

Despite the challenges wildland fire poses to contemporary resource management, many fire-prone ecosystems have adapted over centuries to millennia to intentional landscape burning by people to maintain resources. We combine fieldwork, modeling, and a literature survey to examine the extent and mechanism by which anthropogenic burning alters the spatial grain of habitat mosaics in fire-prone ecosystems. We survey the distribution of Callitris intratropica, a conifer requiring long fire-free intervals for establishment, as an indicator of long-unburned habitat availability under Aboriginal burning in the savannas of Arnhem Land. We then use cellular automata to simulate the effects of burning identical proportions of the landscape under different fire sizes on the emergent patterns of habitat heterogeneity. Finally, we examine the global extent of intentional burning and diversity of objectives using the scientific literature. The current distribution of Callitris across multiple field sites suggested long-unburnt patches are common and occur at fine scales (<0.5 ha), while modeling revealed smaller, patchy disturbances maximize patch age diversity, creating a favorable habitat matrix for Callitris. The literature search provided evidence for intentional landscape burning across multiple ecosystems on six continents, with the number of identified objectives ranging from two to thirteen per study. The fieldwork and modeling results imply that the occurrence of long-unburnt habitat in fire-prone ecosystems may be an emergent property of patch scaling under fire regimes dominated by smaller fires. These findings provide a model for understanding how anthropogenic burning alters spatial and temporal aspects of habitat heterogeneity, which, as the literature survey strongly suggests, warrant consideration across a diversity of geographies and cultures. Our results clarify how traditional fire management shapes fire-prone ecosystems, which despite diverse objectives, has allowed human societies to cope with fire as a recurrent disturbance. PMID:26140206

Biomass burning emissions of reactive gases estimated from satellite data analysis and ecosystem modeling for the Brazilian Amazon region

NASA Astrophysics Data System (ADS)

Potter, Christopher; Brooks-Genovese, Vanessa; Klooster, Steven; Torregrosa, Alicia

2002-10-01

To produce a new daily record of trace gas emissions from biomass burning events for the Brazilian Legal Amazon, we have combined satellite advanced very high resolution radiometer (AVHRR) data on fire counts together for the first time with vegetation greenness imagery as inputs to an ecosystem biomass model at 8 km spatial resolution. This analysis goes beyond previous estimates for reactive gas emissions from Amazon fires, owing to a more detailed geographic distribution estimate of vegetation biomass, coupled with daily fire activity for the region (original 1 km resolution), and inclusion of fire effects in extensive areas of the Legal Amazon (defined as the Brazilian states of Acre, Amapá, Amazonas, Maranhao, Mato Grosso, Pará, Rondônia, Roraima, and Tocantins) covered by open woodland, secondary forests, savanna, and pasture vegetation. Results from our emissions model indicate that annual emissions from Amazon deforestation and biomass burning in the early 1990s total to 102 Tg yr-1 carbon monoxide (CO) and 3.5 Tg yr-1 nitrogen oxides (NOx). Peak daily burning emissions, which occurred in early September 1992, were estimated at slightly more than 3 Tg d-1for CO and 0.1 Tg d-1for NOx flux to the atmosphere. Other burning source fluxes of gases with relatively high emission factors are reported, including methane (CH4), nonmethane hydrocarbons (NMHC), and sulfur dioxide (SO2), in addition to total particulate matter (TPM). We estimate the Brazilian Amazon region to be a source of between one fifth and one third for each of these global emission fluxes to the atmosphere. The regional distribution of burning emissions appears to be highest in the Brazilian states of Maranhao and Tocantins, mainly from burning outside of moist forest areas, and in Pará and Mato Grosso, where we identify important contributions from primary forest cutting and burning. These new daily emission estimates of reactive gases from biomass burning fluxes are designed to be used as detailed spatial and temporal inputs to computer models and data analysis of tropospheric chemistry over the tropical region.

Glycyrrhizin restores the impaired IL-12 production in thermally injured mice.

PubMed

Utsunomiya, T; Kobayashi, M; Ito, M; Herndon, D N; Pollard, R B; Suzuki, F

2001-04-07

Mice 6 days after thermal injury (TI-mice) did not respond to lipopolysaccharide (LPS) stimulation for production of serum interleukin 12 (IL-12; 2 h after LPS stimulation, <20 pg/ml in TI-mice; 1091+/-162 pg/ml in normal mice). However, 2 h after LPS stimulation, 1456+/-118 pg/ml of IL-12 were demonstrated in sera of TI-mice previously treated with a 10 mg/kg i.p. dose of glycyrrhizin (GR). IL-12 was not induced by LPS in sera of normal mice inoculated with burn-associated type 2 T cells (IL-4/IL-10-producing CD8+CD11b+TCRgamma/delta+T cells isolated from spleens of TI-mice). However, IL-12 production was induced by LPS in sera of these mice previously treated with GR or a mixture of monoclonal antibodies (mAbs) for type 2 cytokines. Also, IL-12 production was induced by LPS in TI-mice inoculated with CD4+T cells from spleens of GR-treated normal mice (GR-CD4+T cells, 5x10(6)cells/mouse). Since GR-CD4+T cells have been shown to be antagonistic cells against production of type 2 cytokines by burn-associated type 2 T cells, these results indicate that IL-12 unresponsiveness shown in TI-mice is recovered by GR through the regulation of burn-associated type 2 T cell responses. Copyright 2001 Academic Press.

A model of infected burn wounds using Escherichia coli O18:K1:H7 for the study of gram-negative bacteremia and sepsis.

PubMed

Busch, N A; Zanzot, E M; Loiselle, P M; Carter, E A; Allaire, J E; Yarmush, M L; Warren, H S

2000-06-01

A difficulty that has emerged in the development and preclinical evaluation of adjuvant therapies for gram-negative sepsis is the lack of easily studied animal models that closely mimic human infection. An objective of this study was to adapt a previously described model of infection in burned mice to rats with a defined bacterial strain of Escherichia coli. Challenge with two colonies of live E. coli O18:K1:H7 bacteria into an 8% full-thickness burn of the dorsal skin surface of rats produced predictable bacteremia at 24 to 48 h and 80 to 100% mortality at 3 to 4 days. E. coli O18:K1:H7 was approximately 10-million-fold more virulent than several other gram-negative bacterial strains. The model should be a useful tool in studying the pathogenicity of burn wound infections and in evaluating the efficacy of novel adjuvant therapies for gram-negative sepsis.

Analysis and mapping of post-fire hydrologic hazards for the 2002 Hayman, Coal Seam, and Missionary Ridge wildfires, Colorado

USGS Publications Warehouse

Elliott, J.G.; Smith, M.E.; Friedel, M.J.; Stevens, M.R.; Bossong, C.R.; Litke, D.W.; Parker, R.S.; Costello, C.; Wagner, J.; Char, S.J.; Bauer, M.A.; Wilds, S.R.

2005-01-01

Wildfires caused extreme changes in the hydrologic, hydraulic, and geomorphologic characteristics of many Colorado drainage basins in the summer of 2002. Detailed assessments were made of the short-term effects of three wildfires on burned and adjacent unburned parts of drainage basins. These were the Hayman, Coal Seam, and Missionary Ridge wildfires. Longer term runoff characteristics that reflect post-fire drainage basin recovery expected to develop over a period of several years also were analyzed for two affected stream reaches: the South Platte River between Deckers and Trumbull, and Mitchell Creek in Glenwood Springs. The 10-, 50-, 100-, and 500-year flood-plain boundaries and water-surface profiles were computed in a detailed hydraulic study of the Deckers-to-Trumbull reach. The Hayman wildfire burned approximately 138,000 acres (216 square miles) in granitic terrain near Denver, and the predominant potential hazard in this area is flooding by sediment-laden water along the large tributaries to and the main stem of the South Platte River. The Coal Seam wildfire burned approximately 12,200 acres (19.1 square miles) near Glenwood Springs, and the Missionary Ridge wildfire burned approximately 70,500 acres (110 square miles) near Durango, both in areas underlain by marine shales where the predominant potential hazard is debris-flow inundation of low-lying areas. Hydrographs and peak discharges for pre-burn and post-burn scenarios were computed for each drainage basin and tributary subbasin by using rainfall-runoff models because streamflow data for most tributary subbasins were not available. An objective rainfall-runoff model calibration method based on nonlinear regression and referred to as the ?objective calibration method? was developed and applied to rainfall-runoff models for three burned areas. The HEC-1 rainfall-runoff model was used to simulate the pre-burn rainfall-runoff processes in response to the 100-year storm, and HEC-HMS was used for runoff hydrograph generation. Post-burn rainfall-runoff parameters were determined by adjusting the runoff-curve numbers on the basis of a weighting procedure derived from the U.S. Soil Conservation Service (now the National Resources Conservation Service) equation for precipitation excess and the effect of burn severity. This weighting procedure was determined to be more appropriate than simple area weighting because of the potentially marked effect of even small burned areas on the runoff hydrograph in individual drainage basins. Computed water-peak discharges from HEC-HMS models were increased volumetrically to account for increased sediment concentrations that are expected as a result of accelerated erosion after burning. Peak discharge estimates for potential floods in the South Platte River were increased by a factor that assumed a volumetric sediment concentration (Cv) of 20 percent. Flood hydrographs for the South Platte River and Mitchell Creek were routed down main-stem channels using watershed-routing algorithms included in the HEC-HMS rainfall-runoff model. In areas subject to debris flows in the Coal Seam and Missionary Ridge burned areas, debris-flow discharges were simulated by 100-year rainfall events, and the inflow hydrographs at tributary mouths were simulated by using the objective calibration method. Sediment concentrations (Cv) used in debris-flow simulations were varied through the event, and were initial Cv 20 percent, mean Cv approximately 31 percent, maximum Cv 48 percent, Cv 43 percent at the time of the water hydrograph peak, and Cv 20 percent for the duration of the event. The FLO-2D flood- and debris-flow routing model was used to delineate the area of unconfined debris-flow inundation on selected alluvial fan and valley floor areas. A method was developed to objectively determine the post-fire recovery period for the Hayman and Coal Seam burned areas using runoff-curve numbers (RCN) for all drainage basins for a 50-year period. A

Body protective compound-157 enhances alkali-burn wound healing in vivo and promotes proliferation, migration, and angiogenesis in vitro

PubMed Central

Huang, Tonglie; Zhang, Kuo; Sun, Lijuan; Xue, Xiaochang; Zhang, Cun; Shu, Zhen; Mu, Nan; Gu, Jintao; Zhang, Wangqian; Wang, Yukun; Zhang, Yingqi; Zhang, Wei

2015-01-01

Chemical burns take up a high proportion of burns admissions and can penetrate deep into tissues. Various reagents have been applied in the treatment of skin chemical burns; however, no optimal reagent for skin chemical burns currently exists. The present study investigated the effect of topical body protective compound (BPC)-157 treatment on skin wound healing, using an alkali burn rat model. Topical treatment with BPC-157 was shown to accelerate wound closure following an alkali burn. Histological examination of skin sections with hematoxylin–eosin and Masson staining showed better granulation tissue formation, reepithelialization, dermal remodeling, and a higher extent of collagen deposition when compared to the model control group on the 18th day postwounding. BPC-157 could promote vascular endothelial growth factor expression in wounded skin tissues. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and cell cycle analysis demonstrated that BPC-157 enhanced the proliferation of human umbilical vein endothelial cells (HUVECs). Transwell assay and wound healing assay showed that BPC-157 significantly promoted migration of HUVECs. We also observed that BPC-157 upregulated the expression of VEGF-a and accelerated vascular tube formation in vitro. Moreover, further studies suggested that BPC-157 regulated the phosphorylation level of extracellular signal-regulated kinases 1 and 2 (ERK1/2) as well as its downstream targets, including c-Fos, c-Jun, and Egr-1, which are key molecules involved in cell growth, migration, and angiogenesis. Altogether, our results indicated that BPC-157 treatment may accelerate wound healing in a model of alkali burn-induced skin injury. The therapeutic mechanism may be associated with accelerated granulation tissue formation, reepithelialization, dermal remodeling, and collagen deposition through ERK1/2 signaling pathway. PMID:25995620

Body protective compound-157 enhances alkali-burn wound healing in vivo and promotes proliferation, migration, and angiogenesis in vitro.

PubMed

Huang, Tonglie; Zhang, Kuo; Sun, Lijuan; Xue, Xiaochang; Zhang, Cun; Shu, Zhen; Mu, Nan; Gu, Jintao; Zhang, Wangqian; Wang, Yukun; Zhang, Yingqi; Zhang, Wei

2015-01-01

Chemical burns take up a high proportion of burns admissions and can penetrate deep into tissues. Various reagents have been applied in the treatment of skin chemical burns; however, no optimal reagent for skin chemical burns currently exists. The present study investigated the effect of topical body protective compound (BPC)-157 treatment on skin wound healing, using an alkali burn rat model. Topical treatment with BPC-157 was shown to accelerate wound closure following an alkali burn. Histological examination of skin sections with hematoxylin-eosin and Masson staining showed better granulation tissue formation, reepithelialization, dermal remodeling, and a higher extent of collagen deposition when compared to the model control group on the 18th day postwounding. BPC-157 could promote vascular endothelial growth factor expression in wounded skin tissues. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and cell cycle analysis demonstrated that BPC-157 enhanced the proliferation of human umbilical vein endothelial cells (HUVECs). Transwell assay and wound healing assay showed that BPC-157 significantly promoted migration of HUVECs. We also observed that BPC-157 upregulated the expression of VEGF-a and accelerated vascular tube formation in vitro. Moreover, further studies suggested that BPC-157 regulated the phosphorylation level of extracellular signal-regulated kinases 1 and 2 (ERK1/2) as well as its downstream targets, including c-Fos, c-Jun, and Egr-1, which are key molecules involved in cell growth, migration, and angiogenesis. Altogether, our results indicated that BPC-157 treatment may accelerate wound healing in a model of alkali burn-induced skin injury. The therapeutic mechanism may be associated with accelerated granulation tissue formation, reepithelialization, dermal remodeling, and collagen deposition through ERK1/2 signaling pathway.

Lizard activity and abundance greater in burned habitat of a xeric montane forest

USGS Publications Warehouse

Fouts, Kevin L.; Moore, Clinton; Johnson, Kristine D.; Maerz, John C.

2017-01-01

Restoring the natural or historical state of ecosystems is a common objective among resource managers, but determining whether desired system responses to management actions are occurring is often protracted and challenging. For wildlife, the integration of mechanistic habitat modeling with population monitoring may provide expedited measures of management effectiveness and improve understanding of how management actions succeed or fail to recover populations. Southern Appalachia is a region of high biodiversity that has undergone dramatic change as a result of human activities such as historic logging, exotic invasions, and alteration of disturbance regimes—including reduction in application of fire. Contemporary efforts to restore fire-maintained ecosystems within southern Appalachian forests require tools to assess the effects of fire management practices on individual animal fitness and relate them to corresponding influences on species abundance. Using automated sensing equipment, we investigated the effects of burned forests on reptile habitat suitability within the western portion of Great Smoky Mountains National Park, Tennessee. Specifically, we used microclimate measurements to model northern fence lizard Sceloporus undulatus hyacinthinus diurnal activity budgets in unburned and variable burn age (3–27-y) forest stands. We estimated northern fence lizard occurrence and abundance along transects through burned and unburned forests. Burned forest stands had microclimates that resulted in longer modeled daily activity periods under most conditions during summer. S. undulatus abundance was 4.75 times greater on burned stands compared to paired unburned stands, although the relationship between burn age and abundance was not well determined. Results suggest the more open habitat structure of burned areas within these xeric pine–oak forests may benefit S. undulatus.

Fire frequency, area burned, and severity: A quantitative approach to defining a normal fire year

USGS Publications Warehouse

Lutz, J.A.; Key, C.H.; Kolden, C.A.; Kane, J.T.; van Wagtendonk, J.W.

2011-01-01

Fire frequency, area burned, and fire severity are important attributes of a fire regime, but few studies have quantified the interrelationships among them in evaluating a fire year. Although area burned is often used to summarize a fire season, burned area may not be well correlated with either the number or ecological effect of fires. Using the Landsat data archive, we examined all 148 wildland fires (prescribed fires and wildfires) >40 ha from 1984 through 2009 for the portion of the Sierra Nevada centered on Yosemite National Park, California, USA. We calculated mean fire frequency and mean annual area burned from a combination of field- and satellite-derived data. We used the continuous probability distribution of the differenced Normalized Burn Ratio (dNBR) values to describe fire severity. For fires >40 ha, fire frequency, annual area burned, and cumulative severity were consistent in only 13 of 26 years (50 %), but all pair-wise comparisons among these fire regime attributes were significant. Borrowing from long-established practice in climate science, we defined "fire normals" to be the 26 year means of fire frequency, annual area burned, and the area under the cumulative probability distribution of dNBR. Fire severity normals were significantly lower when they were aggregated by year compared to aggregation by area. Cumulative severity distributions for each year were best modeled with Weibull functions (all 26 years, r2 ??? 0.99; P < 0.001). Explicit modeling of the cumulative severity distributions may allow more comprehensive modeling of climate-severity and area-severity relationships. Together, the three metrics of number of fires, size of fires, and severity of fires provide land managers with a more comprehensive summary of a given fire year than any single metric.

Systematic care management: a comprehensive approach to catastrophic injury management applied to a catastrophic burn injury population--clinical, utilization, economic, and outcome data in support of the model.

PubMed

Kucan, John; Bryant, Ernest; Dimick, Alan; Sundance, Paula; Cope, Nathan; Richards, Reginald; Anderson, Chris

2010-01-01

The new standard for successful burn care encompasses both patient survival and the burn patient's long-term quality of life. To provide optimal long-term recovery from catastrophic injuries, including catastrophic burns, an outcome-based model using a new technology called systematic care management (SCM) has been developed. SCM provides a highly organized system of management throughout the spectrum of care that provides access to outcome data, consistent oversight, broader access to expert providers, appropriate allocation of resources, and greater understanding of total costs. Data from a population of 209 workers' compensation catastrophic burn cases with a mean TBSA of 27.9% who were managed under the SCM model of care were analyzed. The data include treatment type, cost, return to work, and outcomes achieved. Mean duration of management to achieve all guaranteed outcomes was 20 months. Of the 209 injured workers, 152 (72.7%) achieved sufficient recovery to be released to return to work, of which 97 (46.8%) were both released and competitively employed. Assessment of 10 domains of functional independence indicated that 47.2% of injured workers required total assistance at initiation of SCM. However, at termination of SCM, 84% of those injured workers were fully independent in the 10 functional activities. When compared with other burn research outcome data, the results support the value of the SCM model of care.

Seasonal and Interannual Variations in BC Emissions From Open Biomass Burning in Southern Africa From 1998 to 2005

NASA Astrophysics Data System (ADS)

Ito, A.; Akimoto, H.

2006-12-01

We estimate the emissions of black carbon (BC) from open vegetation fires in southern hemisphere Africa from 1998 to 2005 using satellite information in conjunction with a biogeochemical model. Monthly burned areas at a 0.5-degree resolution are estimated from the Visible and Infrared Scanner (VIRS) fire count product and the Moderate Resolution Imaging Spectroradiometer (MODIS) burned area data set associated with the MODIS tree cover imagery in grasslands and woodlands. The monthly fuel load distribution is derived from a 0.5- degree terrestrial carbon cycle model in conjunction with satellite data. The monthly maps of combustion factor and emission factor are estimated using empirical models that predict the effects of fuel conditions on these factors in grasslands and woodlands. Our annual averaged BC emitted per unit area burned is 0.17 g BC m-2 which is consistent with the product of fuel consumption and emission factor typically measured in southern Africa. The BC emissions from open vegetation burning in southern Africa ranged from 0.26 Tg BC yr-1 for 2002 to 0.42 Tg BC yr-1 for 1998. The peak in BC emissions is identical to that from previous top-down estimate using the Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data. The sum of monthly emissions during the burning season in 2000 is in good agreement between our estimate (0.38 Tg) and previous estimate constrained by numerical model and measurements (0.47 Tg).

Disaster planning: the basics of creating a burn mass casualty disaster plan for a burn center.

PubMed

Kearns, Randy D; Conlon, Kathe M; Valenta, Andrea L; Lord, Graydon C; Cairns, Charles B; Holmes, James H; Johnson, Daryhl D; Matherly, Annette F; Sawyer, Dalton; Skarote, Mary Beth; Siler, Sean M; Helminiak, Radm Clare; Cairns, Bruce A

2014-01-01

In 2005, the American Burn Association published burn disaster guidelines. This work recognized that local and state assets are the most important resources in the initial 24- to 48-hour management of a burn disaster. Historical experiences suggest there is ample opportunity to improve local and state preparedness for a major burn disaster. This review will focus on the basics of developing a burn surge disaster plan for a mass casualty event. In the event of a disaster, burn centers must recognize their place in the context of local and state disaster plan activation. Planning for a burn center takes on three forms; institutional/intrafacility, interfacility/intrastate, and interstate/regional. Priorities for a burn disaster plan include: coordination, communication, triage, plan activation (trigger point), surge, and regional capacity. Capacity and capability of the plan should be modeled and exercised to determine limitations and identify breaking points. When there is more than one burn center in a given state or jurisdiction, close coordination and communication between the burn centers are essential for a successful response. Burn surge mass casualty planning at the facility and specialty planning levels, including a state burn surge disaster plan, must have interface points with governmental plans. Local, state, and federal governmental agencies have key roles and responsibilities in a burn mass casualty disaster. This work will include a framework and critical concepts any burn disaster planning effort should consider when developing future plans.

Optimizing mouse models of neurodegenerative disorders: are therapeutics in sight?

PubMed

Lutz, Cathleen M; Osborne, Melissa A

2013-01-01

The genomic and biologic conservation between mice and humans, along with our increasing ability to manipulate the mouse genome, places the mouse as a premier model for deciphering disease mechanisms and testing potential new therapies. Despite these advantages, mouse models of neurodegenerative disease are sometimes difficult to generate and can present challenges that must be carefully addressed when used for preclinical studies. For those models that do exist, the standardization and optimization of the models is a critical step in ensuring success in both basic research and preclinical use. This review looks back on the history of model development for neurodegenerative diseases and highlights the key strategies that have been learned in order to improve the design, development and use of mouse models in the study of neurodegenerative disease.

Aluminum agglomeration involving the second mergence of agglomerates on the solid propellants burning surface: Experiments and modeling

NASA Astrophysics Data System (ADS)

Ao, Wen; Liu, Xin; Rezaiguia, Hichem; Liu, Huan; Wang, Zhixin; Liu, Peijin

2017-07-01

The agglomeration of aluminum particles usually occurs on the burning surface of aluminized composite propellants. It leads to low propellant combustion efficiency and high two-phase flow losses. To reach a thorough understanding of aluminum agglomeration behaviors, agglomeration processes, and particles size distribution of Al/AP/RDX/GAP propellants were studied by using a cinephotomicrography experimental technique, under 5 MPa. Accumulation, aggregation, and agglomeration phenomena of aluminum particles have been inspected, as well as the flame asymmetry of burning agglomerates. Results reveals that the dependency of the mean and the maximum agglomeration diameter to the burning rate and the virgin aluminum size have the same trend. A second-time mergence of multiple agglomerates on the burning surface is unveiled. Two typical modes of second mergence are concluded, based upon vertical and level movement of agglomerates, respectively. The latter mode is found to be dominant and sometimes a combination of the two modes may occur. A new model of aluminum agglomeration on the burning surface of composite propellants is derived to predict the particulates size distribution with a low computational amount. The basic idea is inspired from the well-known pocket models. The pocket size of the region formed by adjacent AP particles is obtained through scanning electron microscopy of the propellant cross-section coupled to an image processing method. The second mergence mechanism, as well as the effect of the burning rate on the agglomeration processes, are included in the present model. The mergence of two agglomerates is prescribed to occur only if their separation distance is less than a critical value. The agglomerates size distribution resulting from this original model match reasonably with the experimental data. Moreover, the present model gives superior results for mean agglomeration diameter compared to common empirical and pocket models. The average prediction error is lower than 5% for the four propellants tested. Results of this study are expected to provide better insight and enrich in the theoretical frame of aluminum agglomeration.

Use of artificial landscapes to isolate controls on burn probability

Treesearch

Marc-Andre Parisien; Carol Miller; Alan A. Ager; Mark A. Finney

2010-01-01

Techniques for modeling burn probability (BP) combine the stochastic components of fire regimes (ignitions and weather) with sophisticated fire growth algorithms to produce high-resolution spatial estimates of the relative likelihood of burning. Despite the numerous investigations of fire patterns from either observed or simulated sources, the specific influence of...

Biomass Combustions and Burning Emissions Inferred from GOES Fire Radiative Power

NASA Astrophysics Data System (ADS)

Zhang, X.; Kondragunta, S.; Schmidt, C.

2007-12-01

Biomass burning significantly affects air quality and climate changes. Current estimates of burning emissions are rather imprecise and vary markedly with different methodologies. This paper investigates biomass burning consumption and emissions using GOES (Geostationary Operational Environmental Satellites) WF_ABBA (Wildfire Automated Biomass Burning Algorithm) fire product. In doing this, we establish a set of representatives in diurnal patterns of half-hourly GOES Fire Radiative Power (FRP) for various ecosystems. The representative patterns are used to fill the missed and poor observations of half hourly FRP in GOES fire data for individual fire pixels. The simulated FRP is directly applied to the calculation of the biomass combusted during fire activities. The FRP-based biomass combustion is evaluated using the estimates using a traditional model which integrates burned area, fuel loading, and combustion factor. In the traditional model calculation, we derive burned areas from GOES WF_ABBA fire size. Fuel loading includes three different types (1) MODIS Vegetation Property-based Fuel System (MVPFS), (2) National Dangerous Rating Systems (NFDRS), and (3) the Fuel Characteristic Classification System (FCCS). By comparing the biomass combustions across the Contiguous United States (CONUS) from 2003-2005, we conclude that FRP is an effective tool to estimate the biomass burning emissions. Finally, we examine the temporal and spatial patterns in biomass combustions and emissions (PM2.5, CO, NH3) across the CONUS.

Effects of Different Types of Burn Wounds and its Dressings on Millimeter-Wave Images

NASA Astrophysics Data System (ADS)

Daniel, Oppelt; Patrick, Korf; Julian, Adametz; Jannis, Groh; Martin, Vossiek; Kristina, Zhuravleva; Ole, Goertz

2018-03-01

Millimeter-wave imaging is a promising technology for diagnosing skin burns, that may make it easier to assess and determine the burn depth in the near future. However, up to now, it has not yet been brought to clinical use due to the lack of clinical trails on patients and a millimeter-wave-aided classification of skin burns. In this paper, in a preliminary step, ex-vivo burned porcine skin is utilized to visualize and quantify skin that has been burned in different ways, and to access its effect on millimeter-wave images. For the first time, a 24 hour study of in-vivo human skin visualizes the effect of wound dressings using a fast imaging system operating at frequencies from 70 to 80 GHz. For validation, the effective relative permittivity of the skin and the dressings are measured using a open-ended coaxial probe. An analytical model is applied to calculate the reflection coefficient which are compared to the intensity of the millimeter-wave images to validate the model.

Applications and Limitations of Mouse Models for Understanding Human Atherosclerosis

PubMed Central

von Scheidt, Moritz; Zhao, Yuqi; Kurt, Zeyneb; Pan, Calvin; Zeng, Lingyao; Yang, Xia; Schunkert, Heribert; Lusis, Aldons J.

2017-01-01

Most of the biological understanding of mechanisms underlying coronary artery disease (CAD) derives from studies of mouse models. The identification of multiple CAD loci and strong candidate genes in large human genome-wide association studies (GWAS) presented an opportunity to examine the relevance of mouse models for the human disease. We comprehensively reviewed the mouse literature, including 827 literature-derived genes, and compared it to human data. First, we observed striking concordance of risk factors for atherosclerosis in mice and humans. Second, there was highly significant overlap of mouse genes with human genes identified by GWAS. In particular, of the 46 genes with strong association signals in CAD-GWAS that were studied in mouse models all but one exhibited consistent effects on atherosclerosis-related phenotypes. Third, we compared 178 CAD-associated pathways derived from human GWAS with 263 from mouse studies and observed that over 50% were consistent between both species. PMID:27916529

Combustion of a Polymer (PMMA) Sphere in Microgravity

NASA Technical Reports Server (NTRS)

Yang, Jiann C.; Hamins, Anthony; Donnelly, Michelle K.

1999-01-01

A series of low gravity, aircraft-based, experiments was conducted to investigate the combustion of supported thermoplastic polymer spheres under varying ambient conditions. The three types of thermoplastic investigated were polymethylmethacrylate (PMMA), polypropylene (PP). and polystyrene (PS). Spheres with diameters ranging from 2 mm to 6.35 mm were tested. The total initial pressure varied from 0.05 MPa to 0. 15 MPa whereas the ambient oxygen concentration varied from 19 % to 30 % (by volume). The ignition system consisted of a pair of retractable energized coils. Two CCD cameras recorded the burning histories of the spheres. The video sequences revealed a number of dynamic events including bubbling and sputtering, as well as soot shell formation and break-up during combustion of the spheres at reduced gravity. The ejection of combusting material from the burning spheres represents a fire hazard that must be considered at reduced gravity. The ejection process was found to be sensitive to polymer type. All average burning rates were measured to increase with initial sphere diameter and oxygen concentration, whereas the initial pressure had little effect. The three thermoplastic types exhibited different burning characteristics. For the same initial conditions, the burning rate of PP was slower than PMMA, whereas the burning rate of PS was comparable to PMMA. The transient diameter of the burning thermoplastic exhibited two distinct periods: an initial period (enduring approximately half of the total burn duration) when the diameter remained approximately constant, and a final period when the square of the diameter linearly decreased with time. A simple homogeneous two-phase model was developed to understand the changing diameter of the burning sphere. Its value is based on a competition between diameter reduction due to mass loss from burning and sputtering, and diameter expansion due to the processes of swelling (density decrease with heating) and bubble growth. The model relies on empirical parameters for input, such as the burning rate and the duration of the initial and final burning periods.

Genetically engineered mouse models for studying inflammatory bowel disease.

PubMed

Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

2016-01-01

Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. Copyright © 2015 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mouse Tumor Biology (MTB): a database of mouse models for human cancer.

PubMed

Bult, Carol J; Krupke, Debra M; Begley, Dale A; Richardson, Joel E; Neuhauser, Steven B; Sundberg, John P; Eppig, Janan T

2015-01-01

The Mouse Tumor Biology (MTB; http://tumor.informatics.jax.org) database is a unique online compendium of mouse models for human cancer. MTB provides online access to expertly curated information on diverse mouse models for human cancer and interfaces for searching and visualizing data associated with these models. The information in MTB is designed to facilitate the selection of strains for cancer research and is a platform for mining data on tumor development and patterns of metastases. MTB curators acquire data through manual curation of peer-reviewed scientific literature and from direct submissions by researchers. Data in MTB are also obtained from other bioinformatics resources including PathBase, the Gene Expression Omnibus and ArrayExpress. Recent enhancements to MTB improve the association between mouse models and human genes commonly mutated in a variety of cancers as identified in large-scale cancer genomics studies, provide new interfaces for exploring regions of the mouse genome associated with cancer phenotypes and incorporate data and information related to Patient-Derived Xenograft models of human cancers. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

The latest animal models of ovarian cancer for novel drug discovery.

PubMed

Magnotti, Elizabeth; Marasco, Wayne A

2018-03-01

Epithelial ovarian cancer is a heterogeneous disease classified into five subtypes, each with a different molecular profile. Most cases of ovarian cancer are diagnosed after metastasis of the primary tumor and are resistant to traditional platinum-based chemotherapeutics. Mouse models of ovarian cancer have been utilized to discern ovarian cancer tumorigenesis and the tumor's response to therapeutics. Areas covered: The authors provide a review of mouse models currently employed to understand ovarian cancer. This article focuses on advances in the development of orthotopic and patient-derived tumor xenograft (PDX) mouse models of ovarian cancer and discusses current humanized mouse models of ovarian cancer. Expert opinion: The authors suggest that humanized mouse models of ovarian cancer will provide new insight into the role of the human immune system in combating and augmenting ovarian cancer and aid in the development of novel therapeutics. Development of humanized mouse models will take advantage of the NSG and NSG-SGM3 strains of mice as well as new strains that are actively being derived.

How Genetically Engineered Mouse Tumor Models Provide Insights Into Human Cancers

PubMed Central

Politi, Katerina; Pao, William

2011-01-01

Genetically engineered mouse models (GEMMs) of human cancer were first created nearly 30 years ago. These early transgenic models demonstrated that mouse cells could be transformed in vivo by expression of an oncogene. A new field emerged, dedicated to generating and using mouse models of human cancer to address a wide variety of questions in cancer biology. The aim of this review is to highlight the contributions of mouse models to the diagnosis and treatment of human cancers. Because of the breadth of the topic, we have selected representative examples of how GEMMs are clinically relevant rather than provided an exhaustive list of experiments. Today, as detailed here, sophisticated mouse models are being created to study many aspects of cancer biology, including but not limited to mechanisms of sensitivity and resistance to drug treatment, oncogene cooperation, early detection, and metastasis. Alternatives to GEMMs, such as chemically induced or spontaneous tumor models, are not discussed in this review. PMID:21263096

Integrating model behavior, optimization, and sensitivity/uncertainty analysis: overview and application of the MOUSE software toolbox

USDA-ARS?s Scientific Manuscript database

This paper provides an overview of the Model Optimization, Uncertainty, and SEnsitivity Analysis (MOUSE) software application, an open-source, Java-based toolbox of visual and numerical analysis components for the evaluation of environmental models. MOUSE is based on the OPTAS model calibration syst...

The evolution of biomass-burning aerosol size distributions due to coagulation: dependence on fire and meteorological details and parameterization

NASA Astrophysics Data System (ADS)

Sakamoto, Kimiko M.; Laing, James R.; Stevens, Robin G.; Jaffe, Daniel A.; Pierce, Jeffrey R.

2016-06-01

Biomass-burning aerosols have a significant effect on global and regional aerosol climate forcings. To model the magnitude of these effects accurately requires knowledge of the size distribution of the emitted and evolving aerosol particles. Current biomass-burning inventories do not include size distributions, and global and regional models generally assume a fixed size distribution from all biomass-burning emissions. However, biomass-burning size distributions evolve in the plume due to coagulation and net organic aerosol (OA) evaporation or formation, and the plume processes occur on spacial scales smaller than global/regional-model grid boxes. The extent of this size-distribution evolution is dependent on a variety of factors relating to the emission source and atmospheric conditions. Therefore, accurately accounting for biomass-burning aerosol size in global models requires an effective aerosol size distribution that accounts for this sub-grid evolution and can be derived from available emission-inventory and meteorological parameters. In this paper, we perform a detailed investigation of the effects of coagulation on the aerosol size distribution in biomass-burning plumes. We compare the effect of coagulation to that of OA evaporation and formation. We develop coagulation-only parameterizations for effective biomass-burning size distributions using the SAM-TOMAS large-eddy simulation plume model. For the most-sophisticated parameterization, we use the Gaussian Emulation Machine for Sensitivity Analysis (GEM-SA) to build a parameterization of the aged size distribution based on the SAM-TOMAS output and seven inputs: emission median dry diameter, emission distribution modal width, mass emissions flux, fire area, mean boundary-layer wind speed, plume mixing depth, and time/distance since emission. This parameterization was tested against an independent set of SAM-TOMAS simulations and yields R2 values of 0.83 and 0.89 for Dpm and modal width, respectively. The size distribution is particularly sensitive to the mass emissions flux, fire area, wind speed, and time, and we provide simplified fits of the aged size distribution to just these input variables. The simplified fits were tested against 11 aged biomass-burning size distributions observed at the Mt. Bachelor Observatory in August 2015. The simple fits captured over half of the variability in observed Dpm and modal width even though the freshly emitted Dpm and modal widths were unknown. These fits may be used in global and regional aerosol models. Finally, we show that coagulation generally leads to greater changes in the particle size distribution than OA evaporation/formation does, using estimates of OA production/loss from the literature.

Study of the ion kinetic effects in ICF run-away burn using a quasi-1D hybrid model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Cheng -Kun; Molvig, Kim; Albright, Brian James

Here, the loss of fuel ions in the Gamow peak and other kinetic effects related to the α particles during ignition, run-away burn, and disassembly stages of an inertial confinement fusion D-T capsule are investigated with a quasi-1D hybrid volume ignition model that includes kinetic ions, fluid electrons, Planckian radiation photons, and a metallic pusher. The fuel ion loss due to the Knudsen effect at the fuel-pusher interface is accounted for by a local-loss model by with an albedo model for ions returning from the pusher wall. The tail refilling and relaxation of the fuel ion distribution are captured withmore » a nonlinear Fokker-Planck solver. Alpha heating of the fuel ions is modeled kinetically while simple models for finite alpha range and electron heating are used. This dynamical model is benchmarked with a 3 T hydrodynamic burn model employing similar assumptions. For an energetic pusher (~40 kJ) that compresses the fuel to an areal density of ~1.07g/cm 2 at ignition, the simulation shows that the Knudsen effect can substantially limit ion temperature rise in runaway burn. While the final yield decreases modestly from kinetic effects of the α particles, large reduction of the fuel reactivity during ignition and runaway burn may require a higher Knudsen loss rate compared to the rise time of the temperatures above ~25 keV when the broad D-T Gamow peak merges into the bulk Maxwellian distribution.« less

Study of the ion kinetic effects in ICF run-away burn using a quasi-1D hybrid model

DOE PAGES

Huang, Cheng -Kun; Molvig, Kim; Albright, Brian James; ...

2017-02-21

Here, the loss of fuel ions in the Gamow peak and other kinetic effects related to the α particles during ignition, run-away burn, and disassembly stages of an inertial confinement fusion D-T capsule are investigated with a quasi-1D hybrid volume ignition model that includes kinetic ions, fluid electrons, Planckian radiation photons, and a metallic pusher. The fuel ion loss due to the Knudsen effect at the fuel-pusher interface is accounted for by a local-loss model by with an albedo model for ions returning from the pusher wall. The tail refilling and relaxation of the fuel ion distribution are captured withmore » a nonlinear Fokker-Planck solver. Alpha heating of the fuel ions is modeled kinetically while simple models for finite alpha range and electron heating are used. This dynamical model is benchmarked with a 3 T hydrodynamic burn model employing similar assumptions. For an energetic pusher (~40 kJ) that compresses the fuel to an areal density of ~1.07g/cm 2 at ignition, the simulation shows that the Knudsen effect can substantially limit ion temperature rise in runaway burn. While the final yield decreases modestly from kinetic effects of the α particles, large reduction of the fuel reactivity during ignition and runaway burn may require a higher Knudsen loss rate compared to the rise time of the temperatures above ~25 keV when the broad D-T Gamow peak merges into the bulk Maxwellian distribution.« less

Health and cost impact of air pollution from biomass burning over the United States

NASA Astrophysics Data System (ADS)

Eslami, E.; Sadeghi, B.; Choi, Y.

2017-12-01

Effective assessment of health and cost effects of air pollution associated with wildfire events is critical for supporting sustainable management and policy analysis to reduce environmental damages. Since biomass burning events result in higher ozone, PM2.5, and NOx concentration values in urban regions due to long-range transport, preliminary results indicated that wildfire events cause a considerable increase in incident estimates and costs. This study aims to evaluate the health and cost impact of biomass burning events over the continental United States using combined air quality and health impact modeling. To meet this goal, a comprehensive air quality modeling scenarios containing biomass burning emissions were conducted using the Community Multiscale Air Quality (CMAQ) modeling system from 2011 to 2014 with a spatial resolution of 12 km. The modeling period includes fire seasons between April and October over the course of four years. By using modeled pollutants concentrations, the USEPA's GIS-based computer program Environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) provides an inclusive figure of health and cost impact caused by changing gaseous and particulate air pollution due to fire events. The basis of BenMAP-CE is the use of a damage-function approach to estimate the health impact of an applied change in air quality by comparing a biomass burning scenario (the one that includes wildfire events) with a baseline scenario (without biomass emissions). This approach considers several factors containing population, exposure to the pollutants, adverse health effects of a particular pollutant, and economic costs. Hence, this study made it capable of showing how biomass burning across U.S. influences people's health in different months, seasons, and regions. Besides, the cost impact of the wildfire events during study periods has also been estimated at both national and regional levels. The results of this study demonstrate the BenMAP-CE can be successfully utilized as a proper tool to obtain health and cost impact of biomass burning events.

Fiber-Supported Droplet Combustion Experiment-2

NASA Technical Reports Server (NTRS)

Colantonio, Renato O.

1998-01-01

A major portion of the energy produced in the world today comes from the burning of liquid hydrocarbon fuels in the form of droplets. Understanding the fundamental physical processes involved in droplet combustion is not only important in energy production but also in propulsion, in the mitigation of combustion-generated pollution, and in the control of the fire hazards associated with handling liquid combustibles. Microgravity makes spherically symmetric combustion possible, allowing investigators to easily validate their droplet models without the complicating effects of gravity. The Fiber-Supported Droplet Combustion (FSDC-2) investigation was conducted in the Microgravity Glovebox facility of the shuttles' Spacelab during the reflight of the Microgravity Science Laboratory (MSL- 1R) on STS-94 in July 1997. FSDC-2 studied fundamental phenomena related to liquid fuel droplet combustion in air. Pure fuels and mixtures of fuels were burned as isolated single and duo droplets with and without forced air convection. FSDC-2 is sponsored by the NASA Lewis Research Center, whose researchers are working in cooperation with several investigators from industry and academia. The rate at which a droplet burns is important in many commercial applications. The classical theory of droplet burning assumes that, for an isolated, spherically symmetric, single-fuel droplet, the gas-phase combustion processes are much faster than the droplet surface regression rate and that the liquid phase is at a uniform temperature equal to the boiling point. Recent, more advanced models predict that both the liquid and gas phases are unsteady during a substantial portion of the droplet's burning history, thus affecting the instantaneous and average burning rates, and that flame radiation is a dominant mechanism that can extinguish flames in a microgravity environment. FSDC-2 has provided well-defined, symmetric droplet burning data including radiative emissions to validate these theoretical models for heptane, decane, ethanol, and methanol fuels. Since most commercial combustion systems burn droplets in a convective environment, data were obtained without and with convective flow over the burning droplet (see the following photos).

Absence of Vsx1 expression in the normal and damaged mouse cornea

PubMed Central

Chow, Robert L.

2011-01-01

Purpose To examine the expression of visual system homeobox 1 (Vsx1) in the mouse cornea and its potential role in the corneal wound response pathway. Methods Expression of Vsx1 was examined by quantitative reverse-transcription PCR (qRT–PCR) in corneal tissue from developing and adult mice and from mice that had undergone alkali-burn corneal wounding. Immunolabeling and Vsx1 knock-in reporter gene expression in wild type and Vsx1 null-mice were used to confirm the qRT–PCR data. Results Using qRT–PCR, Vsx1 expression was not detected in either the postnatal or adult mouse cornea or in corneas following wounding. This qRT–PCR data was supported by the absence of specific Vsx1 immunolabeling and Vsx1 knock-in reporter expression in untreated and wounded corneas. Conclusions In mice, Vsx1 mRNA, protein or reporter gene expression is not detected in the normal or damaged cornea. These results make it uncertain what role VSX1/Vsx1 plays in corneal biology. Future experiments examining the pathogenicity of VSX1 mutations associated with corneal dystrophy are required to rule out species differences and possible non-cell autonomous roles for VSX1 in the cornea. PMID:21437200

The Impact of Media Reporting on the Emergence of Charcoal Burning Suicide in Taiwan

PubMed Central

Chen, Ying-Yeh; Chen, Feng; Gunnell, David; Yip, Paul S. F.

2013-01-01

We investigated the association of the intensity of newspaper reporting of charcoal burning suicide with the incidence of such deaths in Taiwan during 1998–2002. A counting process approach was used to estimate the incidence of suicides and intensity of news reporting. Conditional Poisson generalized linear autoregressive models were performed to assess the association of the intensity of newspaper reporting of charcoal burning and non-charcoal burning suicides with the actual number of charcoal burning and non-charcoal burning suicides the following day. We found that increases in the reporting of charcoal burning suicide were associated with increases in the incidence of charcoal burning suicide on the following day, with each reported charcoal burning news item being associated with a 16% increase in next day charcoal burning suicide (p<.0001). However, the reporting of other methods of suicide was not related to their incidence. We conclude that extensive media reporting of charcoal burning suicides appears to have contributed to the rapid rise in the incidence of the novel method in Taiwan during the initial stage of the suicide epidemic. Regulating media reporting of novel suicide methods may prevent an epidemic spread of such new methods. PMID:23383027

Factors associated with mortality and length of stay in the Oporto burn unit (2006-2009).

PubMed

Bartosch, Isabel; Bartosch, Carla; Egipto, Paula; Silva, Alvaro

2013-05-01

Retrospective studies are essential to evaluate and improve the efficiency of care of burned patients. This study analyses the work done in the burn unit of Hospital de S. João in the north of Portugal. A retrospective review was performed in patients admitted from 2006 to 2009. The study population was characterised regarding patient demographics, admissions profile, burn aetiology, burn site, extension and treatment. Multiple linear and logistic regression models were done in order to elucidate which of these factors influenced the mortality and length of stay. The characteristics before and after the creation of the burn unit, as well as the similarities and differences with the published data of other national and international burn units, are analysed. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

Disrupting the male germ line to find infertility and contraception targets.

PubMed

Archambeault, Denise R; Matzuk, Martin M

2014-05-01

Genetically-manipulated mouse models have become indispensible for broadening our understanding of genes and pathways related to male germ cell development. Until suitable in vitro systems for studying spermatogenesis are perfected, in vivo models will remain the gold standard for inquiry into testicular function. Here, we discuss exciting advances that are allowing researchers faster, easier, and more customizable access to their mouse models of interest. Specifically, the trans-NIH Knockout Mouse Project (KOMP) is working to generate knockout mouse models of every gene in the mouse genome. The related Knockout Mouse Phenotyping Program (KOMP2) is performing systematic phenotypic analysis of this genome-wide collection of knockout mice, including fertility screening. Together, these programs will not only uncover new genes involved in male germ cell development but also provide the research community with the mouse models necessary for further investigations. In addition to KOMP/KOMP2, another promising development in the field of mouse models is the advent of CRISPR (clustered regularly interspaced short palindromic repeat)-Cas technology. Utilizing 20 nucleotide guide sequences, CRISPR/Cas has the potential to introduce sequence-specific insertions, deletions, and point mutations to produce null, conditional, activated, or reporter-tagged alleles. CRISPR/Cas can also successfully target multiple genes in a single experimental step, forgoing the multiple generations of breeding traditionally required to produce mouse models with deletions, insertions, or mutations in multiple genes. In addition, CRISPR/Cas can be used to create mouse models carrying variants identical to those identified in infertile human patients, providing the opportunity to explore the effects of such mutations in an in vivo system. Both the KOMP/KOMP2 projects and the CRISPR/Cas system provide powerful, accessible genetic approaches to the study of male germ cell development in the mouse. A more complete understanding of male germ cell biology is critical for the identification of novel targets for potential non-hormonal contraceptive intervention. Copyright © 2014. Published by Elsevier Masson SAS.

Studying the effects of fuel treatment based on burn probability on a boreal forest landscape.

PubMed

Liu, Zhihua; Yang, Jian; He, Hong S

2013-01-30

Fuel treatment is assumed to be a primary tactic to mitigate intense and damaging wildfires. However, how to place treatment units across a landscape and assess its effectiveness is difficult for landscape-scale fuel management planning. In this study, we used a spatially explicit simulation model (LANDIS) to conduct wildfire risk assessments and optimize the placement of fuel treatments at the landscape scale. We first calculated a baseline burn probability map from empirical data (fuel, topography, weather, and fire ignition and size data) to assess fire risk. We then prioritized landscape-scale fuel treatment based on maps of burn probability and fuel loads (calculated from the interactions among tree composition, stand age, and disturbance history), and compared their effects on reducing fire risk. The burn probability map described the likelihood of burning on a given location; the fuel load map described the probability that a high fuel load will accumulate on a given location. Fuel treatment based on the burn probability map specified that stands with high burn probability be treated first, while fuel treatment based on the fuel load map specified that stands with high fuel loads be treated first. Our results indicated that fuel treatment based on burn probability greatly reduced the burned area and number of fires of different intensities. Fuel treatment based on burn probability also produced more dispersed and smaller high-risk fire patches and therefore can improve efficiency of subsequent fire suppression. The strength of our approach is that more model components (e.g., succession, fuel, and harvest) can be linked into LANDIS to map the spatially explicit wildfire risk and its dynamics to fuel management, vegetation dynamics, and harvesting. Copyright © 2012 Elsevier Ltd. All rights reserved.

Two-Year Gender Differences in Satisfaction With Appearance After Burn Injury and Prediction of Five-Year Depression: A Latent Growth Curve Approach.

PubMed

Al Ghriwati, Nour; Sutter, Megan; Pierce, Bradford S; Perrin, Paul B; Wiechman, Shelley A; Schneider, Jeffrey C

2017-11-01

To use latent growth curve and longitudinal structural equation modeling to examine the 2-year trajectory of satisfaction with appearance in adults with burn injury, and that trajectory's effect on depression 5 years after burn injury. Data were collected at discharge after burn injury hospitalization and at 6 months, 1 year, 2 years, and 5 years postdischarge. The Burn Model Systems (BMS) program consisted of a data center and 5 participating burn centers. The sample consisted of adults (N=720) who were hospitalized for a burn injury, enrolled in the BMS database, and completed measures at least once throughout the 5-year study duration. Not applicable. Satisfaction With Appearance Scale and Patient Health Questionnaire-9 (depression). Women with burn injury reported higher levels of dissatisfaction with their appearance in comparison to their male counterparts over the 2 years after discharge. Individuals with a larger total body surface area (TBSA) affected by a burn also reported greater body dissatisfaction across the postdischarge 2-year period. Results did not support significant gender or TBSA differences in the rate of change of body dissatisfaction trajectories across these 2 years. Individuals with greater body dissatisfaction at 6 months postdischarge tended to have higher depressive symptoms at 5 years. Six month postdischarge, body dissatisfaction scores also mediated the effects of gender and TBSA on depressive symptoms 5 years later. It is recommended that individuals with heightened body image dissatisfaction after a burn, particularly women and those with larger TBSA, participate in evidence-based psychosocial interventions to improve long-term adjustment. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Ocular hydrofluoric acid burns: animal model, mechanism of injury and therapy.

PubMed Central

McCulley, J P

1990-01-01

A series of ocular HF burns was produced in rabbits in order to clarify the nature of the injury and to provide a description of the animal model. Burned eyes were evaluated clinically and allowed to progress for up to 65 days before histologic examination. The mechanism of HF toxicity was investigated through the study of burns produced by chemicals chosen to mimic its pH effects, osmotic effects, and effects of the free fluoride ion alone. The severe progressive caustic effect of HF on the eyes was found to depend on the combination of pH and the toxic effects of the free fluoride ion, together causing extensive dose-related damage to superficial and deep structures of the eye. Mild burns caused reversible ocular injury; whereas more severe burns lead to corneal stromal scarring, vascularization, edema, formation of calcific band keratopathy plus iris and ciliary body fibrosis. An investigation was made of potential treatments for experimental ocular HF burns in rabbits. Topical ointments containing MgO or MgSO4 and irrigations with or subconjunctival injections of H2O or solutions containing NaCl, MgCl2, CaCl2, LaCl3, hyamine, zephiran, calcium gluconate or a mixture of divalent metal ions were tested for toxicity and for therapeutic value in ocular HF burns. Immediate single irrigation with H2O, NaCl or MgCl2 solution was most effective. Other therapeutic agents commonly used in HF skin burn therapy were either too toxic in normal eyes or caused additive damage to burned eyes. Images FIGURE 1 FIGURE 6 FIGURE 7 FIGURE 8 PMID:2095035

A fire model with distinct crop, pasture, and non-agricultural burning: use of new data and a model-fitting algorithm for FINAL.1

NASA Astrophysics Data System (ADS)

Rabin, Sam S.; Ward, Daniel S.; Malyshev, Sergey L.; Magi, Brian I.; Shevliakova, Elena; Pacala, Stephen W.

2018-03-01

This study describes and evaluates the Fire Including Natural & Agricultural Lands model (FINAL) which, for the first time, explicitly simulates cropland and pasture management fires separately from non-agricultural fires. The non-agricultural fire module uses empirical relationships to simulate burned area in a quasi-mechanistic framework, similar to past fire modeling efforts, but with a novel optimization method that improves the fidelity of simulated fire patterns to new observational estimates of non-agricultural burning. The agricultural fire components are forced with estimates of cropland and pasture fire seasonality and frequency derived from observational land cover and satellite fire datasets. FINAL accurately simulates the amount, distribution, and seasonal timing of burned cropland and pasture over 2001-2009 (global totals: 0.434×106 and 2.02×106 km2 yr-1 modeled, 0.454×106 and 2.04×106 km2 yr-1 observed), but carbon emissions for cropland and pasture fire are overestimated (global totals: 0.295 and 0.706 PgC yr-1 modeled, 0.194 and 0.538 PgC yr-1 observed). The non-agricultural fire module underestimates global burned area (1.91×106 km2 yr-1 modeled, 2.44×106 km2 yr-1 observed) and carbon emissions (1.14 PgC yr-1 modeled, 1.84 PgC yr-1 observed). The spatial pattern of total burned area and carbon emissions is generally well reproduced across much of sub-Saharan Africa, Brazil, Central Asia, and Australia, whereas the boreal zone sees underestimates. FINAL represents an important step in the development of global fire models, and offers a strategy for fire models to consider human-driven fire regimes on cultivated lands. At the regional scale, simulations would benefit from refinements in the parameterizations and improved optimization datasets. We include an in-depth discussion of the lessons learned from using the Levenberg-Marquardt algorithm in an interactive optimization for a dynamic global vegetation model.

Genome-Wide Expression Profiling of Five Mouse Models Identifies Similarities and Differences with Human Psoriasis

PubMed Central

Swindell, William R.; Johnston, Andrew; Carbajal, Steve; Han, Gangwen; Wohn, Christian; Lu, Jun; Xing, Xianying; Nair, Rajan P.; Voorhees, John J.; Elder, James T.; Wang, Xiao-Jing; Sano, Shigetoshi; Prens, Errol P.; DiGiovanni, John; Pittelkow, Mark R.; Ward, Nicole L.; Gudjonsson, Johann E.

2011-01-01

Development of a suitable mouse model would facilitate the investigation of pathomechanisms underlying human psoriasis and would also assist in development of therapeutic treatments. However, while many psoriasis mouse models have been proposed, no single model recapitulates all features of the human disease, and standardized validation criteria for psoriasis mouse models have not been widely applied. In this study, whole-genome transcriptional profiling is used to compare gene expression patterns manifested by human psoriatic skin lesions with those that occur in five psoriasis mouse models (K5-Tie2, imiquimod, K14-AREG, K5-Stat3C and K5-TGFbeta1). While the cutaneous gene expression profiles associated with each mouse phenotype exhibited statistically significant similarity to the expression profile of psoriasis in humans, each model displayed distinctive sets of similarities and differences in comparison to human psoriasis. For all five models, correspondence to the human disease was strong with respect to genes involved in epidermal development and keratinization. Immune and inflammation-associated gene expression, in contrast, was more variable between models as compared to the human disease. These findings support the value of all five models as research tools, each with identifiable areas of convergence to and divergence from the human disease. Additionally, the approach used in this paper provides an objective and quantitative method for evaluation of proposed mouse models of psoriasis, which can be strategically applied in future studies to score strengths of mouse phenotypes relative to specific aspects of human psoriasis. PMID:21483750

Mesoscale Modeling of Deflagration-Induced Deconsolidation in Polymer-Bonded Explosives

NASA Astrophysics Data System (ADS)

Springer, H. Keo; Reaugh, J. E.; Glascoe, E. A.; Kercher, J. R.; Friedman, G.

2011-06-01

Initially intact polymer-bonded explosives can transition from conductive burning to more violent convective burning via rapid deconsolidation at higher pressures. The pressure-dependent infiltration of cracks and pores, i.e., damage, by product gases at the burn-front is a key step in the transition to convective burning. However, the relative influence of pre-existing damage and deflagration-induced damage on the transition to convective burning is not well understood. The objective of this study is to investigate the role of explosive constituent properties, microstructure, and deflagration velocity on deconsolidation. We performed simulations using the multi-physics hydrocode, ALE3D. HMX was used as the model energetic grain. We used a JWL form for the unreacted and reacted equation-of-state of the HMX. Simplified strength and failure models were used for the HMX and the binder. The propensity for deconsolidation increased with increasing grain volume fraction, increasing porosity, decreasing binder strength, and increasing deflagration velocity. These studies are important because they enable the development of deflagration-induced damage models, as well as the design of inherently safer explosives. This work performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. This work was funded by the Joint DoD/DOE Munitions Technology Development Program.

Improved Survival of Patients With Extensive Burns: Trends in Patient Characteristics and Mortality Among Burn Patients in a Tertiary Care Burn Facility, 2004-2013.

PubMed

Strassle, Paula D; Williams, Felicia N; Napravnik, Sonia; van Duin, David; Weber, David J; Charles, Anthony; Cairns, Bruce A; Jones, Samuel W

Classic determinants of burn mortality are age, burn size, and the presence of inhalation injury. Our objective was to describe temporal trends in patient and burn characteristics, inpatient mortality, and the relationship between these characteristics and inpatient mortality over time. All patients aged 18 years or older and admitted with burn injury, including inhalation injury only, between 2004 and 2013 were included. Adjusted Cox proportional hazards regression models were used to estimate the relationship between admit year and inpatient mortality. A total of 5540 patients were admitted between 2004 and 2013. Significant differences in sex, race/ethnicity, burn mechanisms, TBSA, inhalation injury, and inpatient mortality were observed across calendar years. Patients admitted between 2011 and 2013 were more likely to be women, non-Hispanic Caucasian, with smaller burn size, and less likely to have an inhalation injury, in comparison with patients admitted from 2004 to 2010. After controlling for patient demographics, burn mechanisms, and differential lengths of stay, no calendar year trends in inpatient mortality were detected. However, a significant decrease in inpatient mortality was observed among patients with extensive burns (≥75% TBSA) in more recent calendar years. This large, tertiary care referral burn center has maintained low inpatient mortality rates among burn patients over the past 10 years. While observed decreases in mortality during this time are largely due to changes in patient and burn characteristics, survival among patients with extensive burns has improved.

Development of a Conceptual Framework to Measure the Social Impact of Burns.

PubMed

Marino, Molly; Soley-Bori, Marina; Jette, Alan M; Slavin, Mary D; Ryan, Colleen M; Schneider, Jeffrey C; Resnik, Linda; Acton, Amy; Amaya, Flor; Rossi, Melinda; Soria-Saucedo, Rene; Kazis, Lewis E

Measuring community reintegration following burn injury is important to assess the efficacy of therapies designed to optimize recovery. This project aims to develop and validate a conceptual framework for understanding the social impact of burn injuries in adults. The framework is critical for developing the item banks used for a computerized adaptive test. We performed a comprehensive literature review and consulted with clinical experts and burn survivors about social life areas impacted by burn injury. Focus groups with burn survivors and clinicians were conducted to inform and validate the framework. Transcripts were coded using grounded theory methodology. The World Health Organization's International Classification of Functioning, Disability and Health, was chosen to ground the content model. The primary construct identified was social participation, which contains two concepts: societal role and personal relationships. The subdomains chosen for item development were work, recreation and leisure, relating with strangers, and romantic, sexual, family, and informal relationships. Qualitative results strongly suggest that the conceptual model fits the constructs for societal role and personal relationships with the respective subdomains. This conceptual framework has guided the implementation of a large-scale calibration study currently underway which will lead to a computerized adaptive test for monitoring the social impacts of burn injuries during recovery.

An LNG release, transport, and fate model system for marine spills.

PubMed

Spaulding, Malcolm L; Swanson, J Craig; Jayko, Kathy; Whittier, Nicole

2007-02-20

LNGMAP, a fully integrated, geographic information based modular system, has been developed to predict the fate and transport of marine spills of LNG. The model is organized as a discrete set of linked algorithms that represent the processes (time dependent release rate, spreading, transport on the water surface, evaporation from the water surface, transport and dispersion in the atmosphere, and, if ignited, burning and associated radiated heat fields) affecting LNG once it is released into the environment. A particle-based approach is employed in which discrete masses of LNG released from the source are modeled as individual masses of LNG or spillets. The model is designed to predict the gas mass balance as a function of time and to display the spatial and temporal evolution of the gas (and radiated energy field). LNGMAP has been validated by comparisons to predictions of models developed by ABS Consulting and Sandia for time dependent point releases from a draining tank, with and without burning. Simulations were in excellent agreement with those performed by ABS Consulting and consistent with Sandia's steady state results. To illustrate the model predictive capability for realistic emergency scenarios, simulations were performed for a tanker entering Block Island Sound. Three hypothetical cases were studied: the first assumes the vessel continues on course after the spill starts, the second that the vessel stops as soon as practical after the release begins (3 min), and the third that the vessel grounds at the closest site practical. The model shows that the areas of the surface pool and the incident thermal radiation field (with burning) are minimized and dispersed vapor cloud area (without burning) maximized if the vessel continues on course. For this case the surface pool area, with burning, is substantially smaller than for the without burning case because of the higher mass loss rate from the surface pool due to burning. Since the vessel speed substantially exceeds the spill spreading rate, both the thermal radiation fields and surface pool trail the vessel. The relative directions and speeds of the wind and vessel movement govern the orientation of the dispersed plume. If the vessel stops, the areas of the surface pool and incident radiation field (with burning) are maximized and the dispersed cloud area (without burning) minimized. The longer the delay in stopping the vessel, the smaller the peak values are for the pool area and the size of the thermal radiation field. Once the vessel stops, the spill pool is adjacent to the vessel and moving down current. The thermal radiation field is oriented similarly. These results may be particularly useful in contingency planning for underway vessels.

Sodium and sulfur release and recapture during black liquor burning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederick, W.J.; Iisa, K.; Wag, K.

1995-08-01

The objective of this study was to provide data on sulfur and sodium volatilization during black liquor burning, and on SO2 capture by solid sodium carbonate and sodium chloride. This data was interpreted and modeled into rate equations suitable for use in computational models for recovery boilers.

Families with burn injury: application in the clinically relevant continuum model.

PubMed

Lehna, Carlee

2011-06-01

This article incorporates the findings from a predominantly qualitative, mixed-method study examining sibling survivors' experiences of a major childhood burn injury into the clinically relevant continuum model as a means of promoting culturally competent and family-centered care. Copyright © 2011 Elsevier Inc. All rights reserved.

Modeling crop residue burning experiments and assessing the fire impacts on air quality

EPA Science Inventory

Prescribed burning is a common land management practice that results in ambient emissions of a variety of primary and secondary pollutants with negative health impacts. The community Multiscale Air Quality (CMAQ) model is used to conduct 2 km grid resolution simulations of prescr...

The burning fuse model of unbecoming in time

NASA Astrophysics Data System (ADS)

Norton, John D.

2015-11-01

In the burning fuse model of unbecoming in time, the future is real and the past is unreal. It is used to motivate the idea that there is something unbecoming in the present literature on the metaphysics of time: its focus is merely the assigning of a label "real."

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather

Treesearch

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Mike D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

2006-01-01

The relative importance of variables in determining area burned is an important management consideration although gaining insights from existing empirical data has proven difficult. The purpose of this study was to compare the sensitivity of modeled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The...

Comparison of the sensitivity of landscape-fire-succession models to variation in terrain, fuel pattern, climate and weather

Treesearch

Geoffrey J. Cary; Robert E. Keane; Robert H. Gardner; Sandra Lavorel; Michael D. Flannigan; Ian D. Davies; Chao Li; James M. Lenihan; T. Scott Rupp; Florent Mouillot

2006-01-01

The purpose of this study was to compare the sensitivity of modelled area burned to environmental factors across a range of independently-developed landscape-fire-succession models. The sensitivity of area burned to variation in four factors, namely terrain (flat, undulating and mountainous), fuel pattern (finely and coarsely clumped), climate (observed, warmer &...

Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

2014-05-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) in Indonesia using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). We focused mainly on the evolution of the fire plume composition and its interaction with the urbanized area of the city-state of Singapore, and on comparisons of modeled and measured aerosol and CO concentrations. Two simulations were run with the model using the complex Volatility Basis Set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic, and b iomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent datasets for comparison including airborne measurements of Particulate Matter with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and Aerosol Optical Depth (AOD) column observations from 4 satellite-based sensors. We found reasonable agreement of the model runs with both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while secondary organic aerosol (SOA) concentration slightly increased. The absolute values of SOA (up to 20 μg m-3) were much lower than those from POA, indicating a minor role of SOA in biomass burning plumes. Our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to biomass and peat burning in Sumatra, but this contribution increased during high burning periods. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 indicating poor air quality. During 17 days this was due to fires, based on the difference between the simulations with and without fires. Local pollution in combination with recirculation of air masses was probably the main cause of poor air quality during the other 18 days, although fires from Sumatra and probably also from Borneo added to the enhanced PM10 concentrations. The model vs. measurement comparisons highlighted that for our study period and region the GFED3 biomass burning aerosol emissions were more in line with observations than found in other studies. This indicates that care should be taken when using AOD to constrain emissions or estimate ground-level air quality. This study also shows the need for relatively high resolution modeling to accurately reproduce the advection of air masses necessary to quantify the impacts and feedbacks on air quality.

Quantitative long term measurements of burns in a rat model using spatial frequency domain imaging and laser speckle imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Ponticorvo, Adrien; Rowland, Rebecca A.; Baldado, Melissa L.; Kennedy, Gordon T.; Saager, Rolf B.; Choi, Bernard; Durkin, Anthony J.

2016-04-01

The ability to accurately assess burn wound severity in a timely manner is a critical component of wound management as it dictates the course of treatment. While full thickness and superficial burns can be easily diagnosed through visual inspection, burns that fall in between these categories are difficult to classify. Additionally, the ability to better quantify different stages of wound healing from a burn of any severity would be important for evaluating the efficacy of different treatment options. Here we present a longitudinal (28 day) study that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn wounds and healing in a murine model. Burn wounds were created using an established technique of a brass comb heated to a given temperature and applied for a set amount of time. They were imaged immediately after the initial injury and then at 2, 4, 7, 14, 21, and 28 days following the injury. Biopsies were taken on the day of the injury in order to verify the extent of the burn damage as well as at different time points after the injury in order to visualize different stages of inflammation and healing. The results of this study suggest that the reduced scattering coefficient measured using SFDI and blood flow as measured using LSI have the potential to provide useful metrics for quantifying the severity of burn injuries as well as track the different stages associated with wound healing progression.

Modeling of marginal burning state of fire spread in live chaparral shrub fuel bed

Treesearch

X. Zhou; S. Mahalingam; D. Weise

2005-01-01

Prescribed burning in chaparral, currently used to manage wildland fuels and reduce wildfire hazard, is often conducted under marginal burning conditions. The relative importance of the fuel and environmental variables that determine fire spread success in chaparral fuels is not quantitatively understood. Based on extensive experimental study, a two-dimensional...

Experimental measurements and numerical modeling of marginal burning in live chaparral fuel beds

Treesearch

X. Zhou; D.R. Weise; S Mahalingam

2005-01-01

An extensive experimental and numerical study was completed to analyze the marginal burning behavior of live chaparral shrub fuels that grow in the mountains of southern California. Laboratory fire spread experiments were carried out to determine the effects of wind, slope, moisture content, and fuel characteristics on marginal burning in fuel beds of common...

Satellite data driven modeling system for predicting air quality and visibility during wildfire and prescribed burn events

NASA Astrophysics Data System (ADS)

Nair, U. S.; Keiser, K.; Wu, Y.; Maskey, M.; Berendes, D.; Glass, P.; Dhakal, A.; Christopher, S. A.

2012-12-01

The Alabama Forestry Commission (AFC) is responsible for wildfire control and also prescribed burn management in the state of Alabama. Visibility and air quality degradation resulting from smoke are two pieces of information that are crucial for this activity. Currently the tools available to AFC are the dispersion index available from the National Weather Service and also surface smoke concentrations. The former provides broad guidance for prescribed burning activities but does not provide specific information regarding smoke transport, areas affected and quantification of air quality and visibility degradation. While the NOAA operational air quality guidance includes surface smoke concentrations from existing fire events, it does not account for contributions from background aerosols, which are important for the southeastern region including Alabama. Also lacking is the quantification of visibility. The University of Alabama in Huntsville has developed a state-of-the-art integrated modeling system to address these concerns. This system based on the Community Air Quality Modeling System (CMAQ) that ingests satellite derived smoke emissions and also assimilates NASA MODIS derived aerosol optical thickness. In addition, this operational modeling system also simulates the impact of potential prescribed burn events based on location information derived from the AFC prescribed burn permit database. A lagrangian model is used to simulate smoke plumes for the prescribed burns requests. The combined air quality and visibility degradation resulting from these smoke plumes and background aerosols is computed and the information is made available through a web based decision support system utilizing open source GIS components. This system provides information regarding intersections between highways and other critical facilities such as old age homes, hospitals and schools. The system also includes satellite detected fire locations and other satellite derived datasets relevant for fire and smoke management.

Additional historical solid rocket motor burns

NASA Astrophysics Data System (ADS)

Wiedemann, Carsten; Homeister, Maren; Oswald, Michael; Stabroth, Sebastian; Klinkrad, Heiner; Vörsmann, Peter

2009-06-01

The use of orbital solid rocket motors (SRM) is responsible for the release of a high number of slag and Al 2O 3 dust particles which contribute to the space debris environment. This contribution has been modeled for the ESA space debris model MASTER (Meteoroid and Space Debris Terrestrial Environment Reference). The current model version, MASTER-2005, is based on the simulation of 1076 orbital SRM firings which mainly contributed to the long-term debris environment. SRM firings on very low earth orbits which produce only short living particles are not considered. A comparison of the modeled flux with impact data from returned surfaces shows that the shape and quantity of the modeled SRM dust distribution matches that of recent Hubble Space Telescope (HST) solar array measurements very well. However, the absolute flux level for dust is under-predicted for some of the analyzed Long Duration Exposure Facility (LDEF) surfaces. This indicates that some past SRM firings are not included in the current event database. Thus it is necessary to investigate, if additional historical SRM burns, like the retro-burn of low orbiting re-entry capsules, may be responsible for these dust impacts. The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules. This paper focuses on the SRM retro-burns of Russian photoreconnaissance satellites, which were used in high numbers during the time of the LDEF mission. It is discussed which types of satellites and motors may have been responsible for this historical contribution. Altogether, 870 additional SRM retro-burns have been identified. An important task is the identification of such missions to complete the current event data base. Different types of motors have been used to de-orbit both large satellites and small film return capsules. The results of simulation runs are presented.

[Effect of topical application of a recombinant adenovirus carrying promyelocytic leukemia gene in a psoriasis-like mouse model].

PubMed

Wang, Qiongyu; Zhang, Aijun; Ma, Huiqun; Wang, Shijie; Ma, Yunyun; Zou, Xingwei; Li, Ruilian

2013-03-01

To investigate the effects of topical treatment with adenovirus-mediated promyelocytic leukemia gene (PML) gene in a psoriasis-like mouse model. The effect of adenovirus-mediated PML gene on the granular layer of mouse tail scale epidermis and epithelial mitosis were observed on longitudinal histological sections prepared from the tail skin and vaginal epithelium of the mice. Adenovirus-mediated PML gene significantly inhibited mitosis of mouse vaginal epithelial cells and promoted the formation of granular layer in mouse tail scale epidermis. The therapeutic effect of PML gene in the psoriasis-like mouse model may be associated with increased granular cells and suppressed epidemic cell proliferation.

Generation of transgenic mouse model using PTTG as an oncogene.

PubMed

Kakar, Sham S; Kakar, Cohin

2015-01-01

The close physiological similarity between the mouse and human has provided tools to understanding the biological function of particular genes in vivo by introduction or deletion of a gene of interest. Using a mouse as a model has provided a wealth of resources, knowledge, and technology, helping scientists to understand the biological functions, translocation, trafficking, and interaction of a candidate gene with other intracellular molecules, transcriptional regulation, posttranslational modification, and discovery of novel signaling pathways for a particular gene. Most importantly, the generation of the mouse model for a specific human disease has provided a powerful tool to understand the etiology of a disease and discovery of novel therapeutics. This chapter describes in detail the step-by-step generation of the transgenic mouse model, which can be helpful in guiding new investigators in developing successful models. For practical purposes, we will describe the generation of a mouse model using pituitary tumor transforming gene (PTTG) as the candidate gene of interest.

Impacts of air pollutants from fire and non-fire emissions on the regional air quality in Southeast Asia

NASA Astrophysics Data System (ADS)

Lee, Hsiang-He; Iraqui, Oussama; Gu, Yefu; Hung-Lam Yim, Steve; Chulakadabba, Apisada; Yiu-Ming Tonks, Adam; Yang, Zhengyu; Wang, Chien

2018-05-01

Severe haze events in Southeast Asia caused by particulate pollution have become more intense and frequent in recent years. Widespread biomass burning occurrences and particulate pollutants from human activities other than biomass burning play important roles in degrading air quality in Southeast Asia. In this study, numerical simulations have been conducted using the Weather Research and Forecasting (WRF) model coupled with a chemistry component (WRF-Chem) to quantitatively examine the contributions of aerosols emitted from fire (i.e., biomass burning) versus non-fire (including fossil fuel combustion, and road dust, etc.) sources to the degradation of air quality and visibility over Southeast Asia. These simulations cover a time period from 2002 to 2008 and are driven by emissions from (a) fossil fuel burning only, (b) biomass burning only, and (c) both fossil fuel and biomass burning. The model results reveal that 39 % of observed low-visibility days (LVDs) can be explained by either fossil fuel burning or biomass burning emissions alone, a further 20 % by fossil fuel burning alone, a further 8 % by biomass burning alone, and a further 5 % by a combination of fossil fuel burning and biomass burning. Analysis of an 24 h PM2.5 air quality index (AQI) indicates that the case with coexisting fire and non-fire PM2.5 can substantially increase the chance of AQI being in the moderate or unhealthy pollution level from 23 to 34 %. The premature mortality in major Southeast Asian cities due to degradation of air quality by particulate pollutants is estimated to increase from ˜ 4110 per year in 2002 to ˜ 6540 per year in 2008. In addition, we demonstrate the importance of certain missing non-fire anthropogenic aerosol sources including anthropogenic fugitive and industrial dusts in causing urban air quality degradation. An experiment of using machine learning algorithms to forecast the occurrence of haze events in Singapore is also explored in this study. All of these results suggest that besides minimizing biomass burning activities, an effective air pollution mitigation policy for Southeast Asia needs to consider controlling emissions from non-fire anthropogenic sources.

Effect of perceived social support and dispositional optimism on the depression of burn patients.

PubMed

He, Fei; Zhou, Qin; Zhao, Zhijing; Zhang, Yuan; Guan, Hao

2016-06-01

Burn wounds have a significant impact on the mental health of patients. This study aimed to investigate the impact of perceived social support and dispositional optimism on depression of burn patients. A total of 246 burn patients accomplished the Multidimensional Scale of Perceived Social Support, the Revised Life Orientation Test, and Depression Scale. The results revealed that both perceived social support and optimism were significantly correlated with depression. Structural equation modeling indicated that optimism partially mediated the relationship between perceived social support and depression. Implications for prevention of depression in burn patients were discussed. © The Author(s) 2014.

ERBE_S4G_WFOV_NF

Atmospheric Science Data Center

2016-06-14

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4G_WFOV_SF

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4GN_WFOV_SF

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4G_SC_ZG

Atmospheric Science Data Center

2016-06-14

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

Evaluation of biomass burning aerosols in the HadGEM3 climate model with observations from the SAMBBA field campaign

NASA Astrophysics Data System (ADS)

Johnson, Ben T.; Haywood, James M.; Langridge, Justin M.; Darbyshire, Eoghan; Morgan, William T.; Szpek, Kate; Brooke, Jennifer K.; Marenco, Franco; Coe, Hugh; Artaxo, Paulo; Longo, Karla M.; Mulcahy, Jane P.; Mann, Graham W.; Dalvi, Mohit; Bellouin, Nicolas

2016-11-01

We present observations of biomass burning aerosol from the South American Biomass Burning Analysis (SAMBBA) and other measurement campaigns, and use these to evaluate the representation of biomass burning aerosol properties and processes in a state-of-the-art climate model. The evaluation includes detailed comparisons with aircraft and ground data, along with remote sensing observations from MODIS and AERONET. We demonstrate several improvements to aerosol properties following the implementation of the Global Model for Aerosol Processes (GLOMAP-mode) modal aerosol scheme in the HadGEM3 climate model. This predicts the particle size distribution, composition, and optical properties, giving increased accuracy in the representation of aerosol properties and physical-chemical processes over the Coupled Large-scale Aerosol Scheme for Simulations in Climate Models (CLASSIC) bulk aerosol scheme previously used in HadGEM2. Although both models give similar regional distributions of carbonaceous aerosol mass and aerosol optical depth (AOD), GLOMAP-mode is better able to capture the observed size distribution, single scattering albedo, and Ångström exponent across different tropical biomass burning source regions. Both aerosol schemes overestimate the uptake of water compared to recent observations, CLASSIC more so than GLOMAP-mode, leading to a likely overestimation of aerosol scattering, AOD, and single scattering albedo at high relative humidity. Observed aerosol vertical distributions were well captured when biomass burning aerosol emissions were injected uniformly from the surface to 3 km. Finally, good agreement between observed and modelled AOD was gained only after scaling up GFED3 emissions by a factor of 1.6 for CLASSIC and 2.0 for GLOMAP-mode. We attribute this difference in scaling factor mainly to different assumptions for the water uptake and growth of aerosol mass during ageing via oxidation and condensation of organics. We also note that similar agreement with observed AOD could have been achieved with lower scaling factors if the ratio of organic carbon to primary organic matter was increased in the models toward the upper range of observed values. Improved knowledge from measurements is required to reduce uncertainties in emission ratios for black carbon and organic carbon, and the ratio of organic carbon to primary organic matter for primary emissions from biomass burning.

An Overview of Regional Experiments on Biomass Burning Aerosols and Related Pollutants in Southeast Asia: From BASE-ASIA and the Dongsha Experiment to 7-SEAS

NASA Technical Reports Server (NTRS)

Lin, Neng-Huei; Tsay, Si-Chee; Maring, Hal B.; Yen, Ming-Cheng; Sheu, Guey-Rong; Wang, Sheng-Hsiang; Chi, Kai Hsien; Chuang, Ming-Tung; Ou-Yang, Chang-Feng; Fu, Joshua S.;

Ulinastatin Suppresses Burn-Induced Lipid Peroxidation and Reduces Fluid Requirements in a Swine Model

PubMed Central

Luo, Hong-Min; Du, Ming-Hua; Lin, Zhi-Long; Hu, Quan; Zhang, Lin; Ma, Li; Wang, Huan; Wen, Yu; Lv, Yi; Lin, Hong-Yuan; Pi, Yu-Li; Hu, Sen; Sheng, Zhi-Yong

2013-01-01

Objective. Lipid peroxidation plays a critical role in burn-induced plasma leakage, and ulinastatin has been reported to reduce lipid peroxidation in various models. This study aims to examine whether ulinastatin reduces fluid requirements through inhibition of lipid peroxidation in a swine burn model. Methods. Forty miniature swine were subjected to 40% TBSA burns and were randomly allocated to the following four groups: immediate lactated Ringer's resuscitation (ILR), immediate LR containing ulinastatin (ILR/ULI), delayed LR resuscitation (DLR), and delayed LR containing ulinastatin (DLR/ULI). Hemodynamic variables, net fluid accumulation, and plasma thiobarbituric acid reactive substances (TBARS) concentrations were measured. Heart, liver, lung, skeletal muscle, and ileum were harvested at 48 hours after burn for evaluation of TBARS concentrations, activities of antioxidant enzymes, and tissue water content. Results. Ulinastatin significantly reduced pulmonary vascular permeability index (PVPI) and extravascular lung water index (ELWI), net fluid accumulation, and water content of heart, lung, and ileum in both immediate or delayed resuscitation groups. Furthermore, ulinastatin infusion significantly reduced plasma and tissue concentrations of TBARS in both immediate or delayed resuscitation groups. Conclusions. These results indicate that ulinastatin can reduce fluid requirements through inhibition of lipid peroxidation. PMID:23738046

Paracrine Factors from Irradiated Peripheral Blood Mononuclear Cells Improve Skin Regeneration and Angiogenesis in a Porcine Burn Model

PubMed Central

Hacker, Stefan; Mittermayr, Rainer; Nickl, Stefanie; Haider, Thomas; Lebherz-Eichinger, Diana; Beer, Lucian; Mitterbauer, Andreas; Leiss, Harald; Zimmermann, Matthias; Schweiger, Thomas; Keibl, Claudia; Hofbauer, Helmut; Gabriel, Christian; Pavone-Gyöngyösi, Mariann; Redl, Heinz; Tschachler, Erwin; Mildner, Michael; Ankersmit, Hendrik Jan

2016-01-01

Burn wounds pose a serious threat to patients and often require surgical treatment. Skin grafting aims to achieve wound closure but requires a well-vascularized wound bed. The secretome of peripheral blood mononuclear cells (PBMCs) has been shown to improve wound healing and angiogenesis. We hypothesized that topical application of the PBMC secretome would improve the quality of regenerating skin, increase angiogenesis, and reduce scar formation after burn injury and skin grafting in a porcine model. Full-thickness burn injuries were created on the back of female pigs. Necrotic areas were excised and the wounds were covered with split-thickness mesh skin grafts. Wounds were treated repeatedly with either the secretome of cultured PBMCs (SecPBMC), apoptotic PBMCs (Apo-SecPBMC), or controls. The wounds treated with Apo-SecPBMC had an increased epidermal thickness, higher number of rete ridges, and more advanced epidermal differentiation than controls. The samples treated with Apo-SecPBMC had a two-fold increase in CD31+ cells, indicating more angiogenesis. These data suggest that the repeated application of Apo-SecPBMC significantly improves epidermal thickness, angiogenesis, and skin quality in a porcine model of burn injury and skin grafting. PMID:27125302

A second-order impact model for forest fire regimes.

PubMed

Maggi, Stefano; Rinaldi, Sergio

2006-09-01

We present a very simple "impact" model for the description of forest fires and show that it can mimic the known characteristics of wild fire regimes in savannas, boreal forests, and Mediterranean forests. Moreover, the distribution of burned biomasses in model generated fires resemble those of burned areas in numerous large forests around the world. The model has also the merits of being the first second-order model for forest fires and the first example of the use of impact models in the study of ecosystems.

What Is the Predictive Value of Animal Models for Vaccine Efficacy in Humans? Reevaluating the Potential of Mouse Models for the Human Immune System.

PubMed

Jameson, Stephen C; Masopust, David

2018-04-02

Much of what we understand about immunology, including the response to vaccines, come from studies in mice because they provide many practical advantages compared with research in higher mammals and humans. Nevertheless, modalities for preventing or treating disease do not always translate from mouse to humans, which has led to increasing scrutiny of the continued merits of mouse research. Here, we summarize the pros and cons of current laboratory mouse models for immunology research and discuss whether overreliance on nonphysiological, ultra-hygienic animal husbandry approaches has limited the ultimate translation potential of mouse-derived data to humans. Alternative approaches are discussed that may extend the use of the mouse model for preclinical studies. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Estimating future burned areas under changing climate in the EU-Mediterranean countries.

PubMed

Amatulli, Giuseppe; Camia, Andrea; San-Miguel-Ayanz, Jesús

2013-04-15

The impacts of climate change on forest fires have received increased attention in recent years at both continental and local scales. It is widely recognized that weather plays a key role in extreme fire situations. It is therefore of great interest to analyze projected changes in fire danger under climate change scenarios and to assess the consequent impacts of forest fires. In this study we estimated burned areas in the European Mediterranean (EU-Med) countries under past and future climate conditions. Historical (1985-2004) monthly burned areas in EU-Med countries were modeled by using the Canadian Fire Weather Index (CFWI). Monthly averages of the CFWI sub-indices were used as explanatory variables to estimate the monthly burned areas in each of the five most affected countries in Europe using three different modeling approaches (Multiple Linear Regression - MLR, Random Forest - RF, Multivariate Adaptive Regression Splines - MARS). MARS outperformed the other methods. Regression equations and significant coefficients of determination were obtained, although there were noticeable differences from country to country. Climatic conditions at the end of the 21st Century were simulated using results from the runs of the regional climate model HIRHAM in the European project PRUDENCE, considering two IPCC SRES scenarios (A2-B2). The MARS models were applied to both scenarios resulting in projected burned areas in each country and in the EU-Med region. Results showed that significant increases, 66% and 140% of the total burned area, can be expected in the EU-Med region under the A2 and B2 scenarios, respectively. Copyright © 2013 Elsevier B.V. All rights reserved.

ERBE_S4G_WFOV_SF_ZG

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4G_WFOV_NF_ZG

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4GN_WFOV_NF_ZG

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4GN_WFOV_SF_ZG

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

Evaluation of protocol change in burn-care management using the Cox proportional hazards model with time-dependent covariates.

PubMed

Ichida, J M; Wassell, J T; Keller, M D; Ayers, L W

1993-02-01

Survival analysis methods are valuable for detecting intervention effects because detailed information from patient records and sensitive outcome measures are used. The burn unit at a large university hospital replaced routine bathing with total body bathing using chlorhexidine gluconate for antimicrobial effect. A Cox proportional hazards model was used to analyse time from admission until either infection with Staphylococcus aureus or discharge for 155 patients, controlling for burn severity and two time-dependent covariates: days until first wound excision and days until first administration of prophylactic antibiotics. The risk of infection was 55 per cent higher in the historical control group, although not statistically significant. There was also some indication that early wound excision may be important as an infection-control measure for burn patients.

Pressure Amplification Off High Impedance Barriers in DDT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heatwole, Eric Mann; Broilo, Robert M.; Kistle, Trevin Joseph

The Deflagration-to-Detonation Transition (DDT) in one-dimensional porous explosive, where combustion in an explosive transitions to detonation, can be described by the following model. This simplified model proceeds in five steps, as follows: 1) Ignition of the explosive, surface burning. 2) Convective burning, with the flame front penetrating through the porous network of the explosive. This proceeds until the pressure grows high enough to result in choked flow in the pores restricting the convective burn. 3) The choked flow results in the formation of a high-density compact of explosive. This compact is driven into undisturbed material by the pressure of themore » burning explosive. See Figure1. 4) The compression of the undisturbed porous explosive by the compact leads to the ignition of a compressive burn. This builds in pressure until a supported shock forms. 5) The shock builds in pressure until detonation occurs. See Figure 2 for an overview streak of the proceeding steps.« less

Protective effect of silk fibroin in burn injury in rat model.

PubMed

Aykac, Asli; Karanlik, Buse; Sehirli, Ahmet Ozer

2018-01-30

Activation of pro-inflamatuar pathways play major role in formation of major complications as a result of burns. This study was planned to investigate the protective effect of Silk Fibroin in lung injury caused by burn in the experimental rat model. After rinsing the skin of rats under ether anesthesia, the exposed back region, covers 30% of the total body, was kept in the 90°C water bath for 10s. The control rats were kept in the 25°C water bath for 10s. Immediately after burning process, silk fibroin was administered orally at a dose of 600mg/kg. After 24h following burning from all groups the levels of TNF-α, IL-1β in blood samples and the MDA, GSH and the activity of MPO were determined from taken lung tissues. Moreover, the expression of Bcl-2/Bax, Caspase-3 and Caspase-9 were determined. Significant increase in TNF-α, IL-1β, Casp-3 and Casp-9 levels were observed in the Silk Fibroin-treated burn group (p<0.05) whereas for ratio of Bcl-2/Bax, a significant reduction was observed compared to control group (p<0.05). Increased levels of TNF-α, IL-1β, Caspase-3 and Caspase-9 in Silk Fibroin-treated burn groups were found to be reversed. Silk fibroin can be an effective biomaterial in diminishing burn injury in tissue and apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Mouse Models in Bone Marrow Transplantation and Adoptive Cellular Therapy

PubMed Central

Arber, Caroline; Brenner, Malcolm K.; Reddy, Pavan

2014-01-01

Mouse models of transplantation have been indispensable to the development of bone marrow transplantation (BMT). Their role in the generation of basic science knowledge is invaluable and is subject to discussion below. However, this article focuses on the direct role and relevance of mouse models towards the clinical development and advances in BMT and adoptive T-cell therapy for human diseases. The authors aim to present a thoughtful perspective on the pros and cons of mouse models while noting that despite imperfections these models are obligatory for the development of science-based medicine. PMID:24216170

The Associations of Gender With Social Participation of Burn Survivors: A Life Impact Burn Recovery Evaluation Profile Study.

PubMed

Levi, Benjamin; Kraft, Casey T; Shapiro, Gabriel D; Trinh, Nhi-Ha T; Dore, Emily C; Jeng, James; Lee, Austin F; Acton, Amy; Marino, Molly; Jette, Alan; Armstrong, Elizabeth A; Schneider, Jeffrey C; Kazis, Lewis E; Ryan, Colleen M

2018-05-04

Burn injury can be debilitating and affect survivors' quality of life in a profound fashion. Burn injury may also lead to serious psychosocial challenges that have not been adequately studied and addressed. Specifically, there has been limited research into the associations of burn injury on community reintegration based on gender. This work analyzed data from 601 burn survivors who completed field testing of a new measure of social participation for burn survivors, the Life Impact Burn Recovery Evaluation (LIBRE) Profile. Differences in item responses between men and women were examined. Scores on the six LIBRE Profile scales were then compared between men and women using analysis of variance and adjusted linear multivariate regression modeling. Overall, men scored significantly better than women on four of the six LIBRE Profile scales: Sexual Relationships, Social Interactions, Work & Employment, and Romantic Relationships. Differences were not substantially reduced after adjustment for demographic characteristics and burn size. Men scored better than women in most of the areas measured by the LIBRE Profile. These gender differences are potentially important for managing burn patients during the post-injury recovery period.

Centralized mouse repositories.

PubMed

Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

2012-10-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

Centralized Mouse Repositories

PubMed Central

Donahue, Leah Rae; de Angelis, Martin Hrabe; Hagn, Michael; Franklin, Craig; Lloyd, K. C. Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T.

2013-01-01

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world. PMID:22945696

Importance of transboundary transport of biomass burning emissions to regional air quality in Southeast Asia during a high fire event

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G. R.; Balasubramanian, R.; Betha, R.

2015-01-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled a large fire-induced haze episode in 2006 stemming mostly from Indonesia using the Weather Research and Forecasting model coupled with chemistry (WRF-Chem). We focused on the evolution of the fire plume composition and its interaction with the urbanized area of the city state of Singapore, and on comparisons of modeled and measured aerosol and carbon monoxide (CO) concentrations. Two simulations were run with WRF-Chem using the complex volatility basis set (VBS) scheme to reproduce primary and secondary aerosol evolution and concentration. The first simulation referred to as WRF-FIRE included anthropogenic, biogenic and biomass burning emissions from the Global Fire Emissions Database (GFED3) while the second simulation referred to as WRF-NOFIRE was run without emissions from biomass burning. To test model performance, we used three independent data sets for comparison including airborne measurements of particulate matter (PM) with a diameter of 10 μm or less (PM10) in Singapore, CO measurements in Sumatra, and aerosol optical depth (AOD) column observations from four satellite-based sensors. We found reasonable agreement between the model runs and both ground-based measurements of CO and PM10. The comparison with AOD was less favorable and indicated the model underestimated AOD, although the degree of mismatch varied between different satellite data sets. During our study period, forest and peat fires in Sumatra were the main cause of enhanced aerosol concentrations from regional transport over Singapore. Analysis of the biomass burning plume showed high concentrations of primary organic aerosols (POA) with values up to 600 μg m-3 over the fire locations. The concentration of POA remained quite stable within the plume between the main burning region and Singapore while the secondary organic aerosol (SOA) concentration slightly increased. However, the absolute concentrations of SOA (up to 20 μg m-3) were much lower than those from POA, indicating a minor role of SOA in these biomass burning plumes. Our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to biomass and peat burning in Sumatra, but this contribution increased during high burning periods. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 indicating poor air quality. During 17 days this was due to fires, based on the difference between the simulations with and without fires. Local pollution in combination with recirculation of air masses was probably the main cause of poor air quality during the other 18 days, although fires from Sumatra and probably also from Kalimantan (Indonesian part of the island of Borneo) added to the enhanced PM10 concentrations. The model versus measurement comparisons highlighted that for our study period and region the GFED3 biomass burning aerosol emissions were more in line with observations than found in other studies. This indicates that care should be taken when using AOD to constrain emissions or estimate ground-level air quality. This study also shows the need for relatively high resolution modeling to accurately reproduce the advection of air masses necessary to quantify the impacts and feedbacks on regional air quality.

Ensemble modeling to predict habitat suitability for a large-scale disturbance specialist

PubMed Central

Latif, Quresh S; Saab, Victoria A; Dudley, Jonathan G; Hollenbeck, Jeff P

2013-01-01

To conserve habitat for disturbance specialist species, ecologists must identify where individuals will likely settle in newly disturbed areas. Habitat suitability models can predict which sites at new disturbances will most likely attract specialists. Without validation data from newly disturbed areas, however, the best approach for maximizing predictive accuracy can be unclear (Northwestern U.S.A.). We predicted habitat suitability for nesting Black-backed Woodpeckers (Picoides arcticus; a burned-forest specialist) at 20 recently (≤6 years postwildfire) burned locations in Montana using models calibrated with data from three locations in Washington, Oregon, and Idaho. We developed 8 models using three techniques (weighted logistic regression, Maxent, and Mahalanobis D2 models) and various combinations of four environmental variables describing burn severity, the north–south orientation of topographic slope, and prefire canopy cover. After translating model predictions into binary classifications (0 = low suitability to unsuitable, 1 = high to moderate suitability), we compiled “ensemble predictions,” consisting of the number of models (0–8) predicting any given site as highly suitable. The suitability status for 40% of the area burned by eastside Montana wildfires was consistent across models and therefore robust to uncertainty in the relative accuracy of particular models and in alternative ecological hypotheses they described. Ensemble predictions exhibited two desirable properties: (1) a positive relationship with apparent rates of nest occurrence at calibration locations and (2) declining model agreement outside surveyed environments consistent with our reduced confidence in novel (i.e., “no-analogue”) environments. Areas of disagreement among models suggested where future surveys could help validate and refine models for an improved understanding of Black-backed Woodpecker nesting habitat relationships. Ensemble predictions presented here can help guide managers attempting to balance salvage logging with habitat conservation in burned-forest landscapes where black-backed woodpecker nest location data are not immediately available. Ensemble modeling represents a promising tool for guiding conservation of large-scale disturbance specialists. PMID:24340177

A Mathematical Model of the Human Small Intestine Following Acute Radiation and Burn Exposures

DTIC Science & Technology

2016-08-01

Acronyms and Symbols ARA Applied Research Associates, Inc. ARS Acute radiation syndrome d Days DE Differential Evolution DTRA Defense Threat...04-08-2016 Technical Report A Mathematical Model of the Human Small Intestine Following Acute Radiation and Burn Exposures HDTRA1...epithelial cells to acute radiation alone. The model has been modified for improved radiation response, and an addition to the model allows for thermal injury

ERBE_S4G_WFOV_NF_N10

Atmospheric Science Data Center

2016-06-14

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

ERBE_S4GN_WFV_NF_N10

Atmospheric Science Data Center

2016-06-15

... well do climate models work? A Burning Question   Evidence suggests that atmospheric aerosols from biomass burning may offset global warming caused by greenhouse gases. Absorption of Solar Radiation ...

Henslow's sparrow winter-survival estimates and response to prescribed burning

USGS Publications Warehouse

Thatcher, B.S.; Krementz, D.G.; Woodrey, M.S.

2006-01-01

Wintering Henslow's sparrow (Ammodramus henslowii) populations rely on lands managed with prescribed burning, but the effects of various burn regimes on their overwinter survival are unknown. We studied wintering Henslow's sparrows in coastal pine savannas at the Mississippi Sandhill Crane National Wildlife Refuge, Jackson County, Mississippi, USA, during January and February 2001 and 2002. We used the known-fate modeling procedure in program MARK to evaluate the effects of burn age (1 or 2 growing seasons elapsed), burn season (growing, dormant), and calendar year on the survival rates of 83 radiomarked Henslow's sparrows. We found strong evidence that Henslow's sparrow survival rates differed by burn age (with higher survival in recently burned sites) and by year (with lower survival rates in 2001 likely because of drought conditions). We found some evidence that survival rates also differed by bum season (with higher survival in growing-season sites), although the effects of burn season were only apparent in recently burned sites. Avian predation was the suspected major cause of mortality (causing 6 of 14 deaths) with 1 confirmed loggerhead shrike (Lanius ludovicianus) depredation. Our results indicated that recently burned savannas provide high-quality wintering habitats and suggested that managers can improve conditions for wintering Henslow's sparrows by burning a large percentage of savannas each year.

Global Burned Area and Biomass Burning Emissions from Small Fires

NASA Technical Reports Server (NTRS)

Randerson, J. T.; Chen, Y.; vanderWerf, G. R.; Rogers, B. M.; Morton, D. C.

2012-01-01

In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity analyses of key model parameters caused estimates of global burned area increases from small fires to vary between 24% and 54%. Biomass burning carbon emissions increased by 35% at a global scale when small fires were included in GFED3, from 1.9 Pg C/yr to 2.5 Pg C/yr. The contribution of tropical forest fires to year-to-year variability in carbon fluxes increased because small fires amplified emissions from Central America, South America and Southeast Asia-regions where drought stress and burned area varied considerably from year to year in response to El Nino-Southern Oscillation and other climate modes.

Watershed improvement using prescribed burns as a way to restore aquatic habitat for native fish

Treesearch

David F. Gori; Dana Backer

2005-01-01

The Nature Conservancy and Bureau of Land Management are testing a model that prescribed burns can be used to increase perennial grass cover, reduce shrubs in desert grassland, and improve watershed condition and aquatic habitat. Results of a prescribed burn in the Hot Springs Creek watershed on Muleshoe Ranch CMA demonstrated the predicted vegetation changes and...

Modeling soil heating and moisture transport under extreme conditions: Forest fires and slash pile burns

Treesearch

W. J. Massman

2012-01-01

Heating any soil during a sufficiently intense wildfire or prescribed burn can alter it irreversibly, causing many significant, long-term biological, chemical, and hydrological effects. Given the climate-change-driven increasing probability of wildfires and the increasing use of prescribed burns by land managers, it is important to better understand the dynamics of the...

Evaluating alternative prescribed burning policies to reduce net economic damages from wildfire

Treesearch

D. Evan Mercer; Jeffrey P. Prestemon; David T. Butry; John M. Pye

2007-01-01

We estimate a wildfire risk model with a new measure of wildfire output, intensity-weighted risk and use it in Monte Carlo simulations to estimate welfare changes from alternative prescribed burning policies. Using Volusia County, Florida as a case study, an annual prescribed burning rate of 13% of all forest lands maximizes net welfare; ignoring the effects on...

Experimental Modeling of the Effect of Terrain Slope on Marginal Burning

Treesearch

X. Zhou; S. Mahalingam; D. Weise

2005-01-01

A series of laboratory fire spread experiments were completed to analyze the effect of terrain slope on marginal burning behavior of live chaparral shrub fuels that grow in the mountains of southern California. We attempted to burn single species fuel beds of four common chaparral plants under various fuel bed configurations and ambient conditions. Seventy-three (or 42...

Model assessing the impact of biomass burning on air quality and photochemistry in Mexico City

Treesearch

W. Lei; G. Li; C. Wiedinmyer; R. J. Yokelson; L. T. Molina

2010-01-01

Biomass burning is a major global emission source for trace gases and particulates. Various multi-platform measurements during the Mexico City Metropolitan Area (MCMA)-2003 and Megacity Initiative: Local and Global Research Observations (MILAGRO)-2006 campaigns suggest significant influences of biomass burning (BB) on air quality in Mexico City during the dry season,...

Collagen-cellulose nanocrystal scaffolds containing curcumin-loaded microspheres on infected full-thickness burns repair.

PubMed

Guo, Rui; Lan, Yong; Xue, Wei; Cheng, Biao; Zhang, Yuanming; Wang, Changyong; Ramakrishna, Seeram

2017-12-01

Burn infection is a serious problem that delays wound healing and leads to death. Curcumin (Cur) has been shown to exhibit antioxidant, anti-inflammatory, antimicrobial and anticarcinogenic activity. However, its instability, extremely low aqueous solubility and bioavailability in physiological fluids may make it difficult to maintain local Cur concentrations above the minimum inhibitory concentration for burn infection treatment. The objective of this study was to construct complexes of Cur/gelatin microspheres (GMs) and porous collagen (Coll)-cellulose nanocrystals (CNCs) composite scaffolds for full-thickness burn infection treatment. The Cur/GMs/Coll-CNCs scaffolds had high porosity, available pore size, and a long and sustained Cur release profile. Furthermore, the composite scaffold exhibited remarkably strong antibacterial activity. Hence, we evaluated the wound-healing effects and antibacterial properties of Cur/GMs/Coll-CNCs scaffolds in a rat full-thickness burn infection model. The Cur/GMs/Coll-CNCs scaffold was able to prevent not only local inflammation but also accelerated dermis regeneration. Thus, we conclude that Cur/GMs/Coll-CNCs scaffolds can act as an effective dermal regeneration template for full-thickness burn wound infection healing in rats models. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Studies of ion kinetic effects in OMEGA shock-driven implosions using fusion burn imaging

NASA Astrophysics Data System (ADS)

Rosenberg, M. J.; Seguin, F. H.; Rinderknecht, H. G.; Sio, H.; Zylstra, A. B.; Gatu Johnson, M.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Amendt, P. A.; Wilks, S. C.; Zimmerman, G.; Hoffman, N. M.; Kagan, G.; Molvig, K.; Glebov, V. Yu.; Stoeckl, C.; Marshall, F. J.; Seka, W.; Delettrez, J. A.; Sangster, T. C.; Betti, R.; Meyerhofer, D. D.; Atzeni, S.; Nikroo, A.

2014-10-01

Ion kinetic effects have been inferred in a series of shock-driven implosions at OMEGA from an increasing yield discrepancy between observations and hydrodynamic simulations as the ion-ion mean free path increases. To more precisely identify the nature and impact of ion kinetic effects, spatial burn profile measurements of DD and D3He reactions in these D3He-filled shock-driven implosions are presented and contrasted to both purely hydrodynamic models and models that include ion kinetic effects. It is shown that in implosions where the ion mean free path is equal to or greater than the size of the fuel region, purely hydrodynamic models fail to capture the observed burn profiles, while a model that includes ion diffusion is able to recover the observed burn profile shape. These results further elucidate the ion kinetic mechanisms that are present under long mean-free-path conditions after shock convergence in both shock-driven and ablatively-driven implosions. This work was supported in part by the U.S. DOE, NLUF, LLE, and LLNL.

Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

NASA Astrophysics Data System (ADS)

Saxe, Samuel; Hogue, Terri S.; Hay, Lauren

2018-02-01

This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors strongly influence response. Spearman correlation identified NDVI, aridity index, percent of a watershed's precipitation that falls as rain, and slope as being positively correlated with post-fire streamflow response. This metric also suggested a negative correlation between response and the soil erodibility factor, watershed area, and percent low burn severity. Regression models identified only moderate burn severity and watershed area as being consistently positively/negatively correlated, respectively, with response. The random forest model identified only slope and percent area burned as significant watershed parameters controlling response. Results will help inform post-fire runoff management decisions by helping to identify expected changes to flow regimes, as well as facilitate parameterization for model application in burned watersheds.

Molecular Indicators of Stress-Induced Neuroinflammation in a Mouse Model Simulating Features of Post-Traumatic Stress Disorder (Open Access)

DTIC Science & Technology

2017-05-23

OPEN ORIGINAL ARTICLE Molecular indicators of stress-induced neuroinflammation in a mouse model simulating features of post -traumatic stress disorder... post -traumatic stress disorder (PTSD). The model involved exposure of an intruder (male C57BL/6) mouse to a resident aggressor (male SJL) mouse for 5...revealed that neurogenesis and synaptic plasticity pathways were activated during the early responses but were inhibited after the later post -trauma

Pattern of unintentional burns: A hospital based study from Pakistan.

PubMed

Adil, Syed Omair; Ibran, Ehmer-Al; Nisar, Nighat; Shafique, Kashif

2016-09-01

Burns are major cause of morbidity and mortality in developing countries. Better understanding of the nature and extent of injury remains the major and only available way to halt the occurrence of the event. The present study was conducted to determine the prevalence of by self and by other unintentional burn, their comparison and the possible mode of acquisition by obtaining the history of exposure to known risk factors. A cross-sectional questionnaire based survey was conducted in Burns Centre of Civil Hospital Karachi, Pakistan and 324 hospitalized adult patients with unintentional burns were consecutively interviewed during August 2013 to February 2014. Information was collected on socio-demographic profile. The source of burn, affected body part and place of injury acquisition in terms of home, outside or work were also noted. Logistic regression model was conducted using SPSS software. Out of 324 patients, 295 (91%) had unintentional burn by self and 29 (9%) had unintentional burn by others. Male gender were 2.37 times and no schooling were 1.75 times more likely to have self-inflicted unintentional burn. Lower limb and head and neck were less likely to involve in unintentional burn by self. The burden of unintentional burn by self was considerably higher. Male gender and no schooling were found more at risk to have unintentional burn by self. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Genetic characterization and improved genotyping of the dysferlin-deficient mouse strain Dysf (tm1Kcam).

PubMed

Wiktorowicz, Tatiana; Kinter, Jochen; Kobuke, Kazuhiro; Campbell, Kevin P; Sinnreich, Michael

2015-01-01

Mouse models of dysferlinopathies are valuable tools with which to investigate the pathomechanisms underlying these diseases and to test novel therapeutic strategies. One such mouse model is the Dysf (tm1Kcam) strain, which was generated using a targeting vector to replace a 12-kb region of the dysferlin gene and which features a progressive muscular dystrophy. A prerequisite for successful animal studies using genetic mouse models is an accurate genotyping protocol. Unfortunately, the lack of robustness of currently available genotyping protocols for the Dysf (tm1Kcam) mouse has prevented efficient colony management. Initial attempts to improve the genotyping protocol based on the published genomic structure failed. These difficulties led us to analyze the targeted locus of the dysferlin gene of the Dysf (tm1Kcam) mouse in greater detail. In this study we resequenced and analyzed the targeted locus of the Dysf (tm1Kcam) mouse and developed a novel PCR protocol for genotyping. We found that instead of a deletion, the dysferlin locus in the Dysf (tm1Kcam) mouse carries a targeted insertion. This genetic characterization enabled us to establish a reliable method for genotyping of the Dysf (tm1Kcam) mouse, and thus has made efficient colony management possible. Our work will make the Dysf (tm1Kcam) mouse model more attractive for animal studies of dysferlinopathies.

Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil

PubMed Central

Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L.; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

2016-01-01

Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species’ specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it did affect the richness, number of individuals, success of some species, and seemed to shape the boundary of these forests as shown by the difference in the positioning of these species along the inundation gradient. PMID:27280879

Inundation and Fire Shape the Structure of Riparian Forests in the Pantanal, Brazil.

PubMed

Arruda, Wellinton de Sá; Oldeland, Jens; Paranhos Filho, Antonio Conceição; Pott, Arnildo; Cunha, Nicolay L; Ishii, Iria Hiromi; Damasceno-Junior, Geraldo Alves

2016-01-01

Inundation and fire can affect the structure of riparian vegetation in wetlands. Our aim was to verify if there are differences in richness, abundance, basal area, composition and topographic preference of woody species in riparian forests related to the fire history, flooding duration, or the interaction between both. The study was conducted in the riparian forests of the Paraguay River some of which were burned three times between 2001 and 2011. We sampled trees with a girth of at least 5 cm at breast height in 150 5 × 10 m plots (79 burned and 71 unburned). We also measured height of the flood mark and estimated the flooding duration of each plot. We performed Generalized Linear Mixed Models to verify differences in richness, basal area, and abundance of individuals associated to interaction of fire and inundation. We used an analysis of similarity (ANOSIM) and indicator species analysis to identify differences in composition of species and the association with burned and unburned area according to different levels of inundation. Finally, we used a hierarchical set of Generalized Linear Models (GLM), the so-called HOF models, to analyse each species' specific response to inundation based on topography and to determine their preferred optimal topographic position for both burned as well as unburned areas. Richness was positively associated with elevation only in burned areas while abundance was negatively influenced by inundation only in burned areas. Basal area was negatively associated with time of inundation independent of fire history. There were 15 species which were significant indicators for at least one combination of the studied factors. We found nine species in burned areas and 15 in unburned areas, with response curves in HOF models along the inundation gradient. From these, five species shifted their optimal position along the inundation gradient in burned areas. The interaction of fire and inundation did not appear to affect the basal area, but it did affect the richness, number of individuals, success of some species, and seemed to shape the boundary of these forests as shown by the difference in the positioning of these species along the inundation gradient.

Mid-21st-century climate changes increase predicted fire occurrence and fire season length, Northern Rocky Mountains, United States

USGS Publications Warehouse

Riley, Karin L.; Loehman, Rachel A.

2016-01-01

Climate changes are expected to increase fire frequency, fire season length, and cumulative area burned in the western United States. We focus on the potential impact of mid-21st-century climate changes on annual burn probability, fire season length, and large fire characteristics including number and size for a study area in the Northern Rocky Mountains. Although large fires are rare they account for most of the area burned in western North America, burn under extreme weather conditions, and exhibit behaviors that preclude methods of direct control. Allocation of resources, development of management plans, and assessment of fire effects on ecosystems all require an understanding of when and where fires are likely to burn, particularly under altered climate regimes that may increase large fire occurrence. We used the large fire simulation model FSim to model ignition, growth, and containment of wildfires under two climate scenarios: contemporary (based on instrumental weather) and mid-century (based on an ensemble average of global climate models driven by the A1B SRES emissions scenario). Modeled changes in fire patterns include increased annual burn probability, particularly in areas of the study region with relatively short contemporary fire return intervals; increased individual fire size and annual area burned; and fewer years without large fires. High fire danger days, represented by threshold values of Energy Release Component (ERC), are projected to increase in number, especially in spring and fall, lengthening the climatic fire season. For fire managers, ERC is an indicator of fire intensity potential and fire economics, with higher ERC thresholds often associated with larger, more expensive fires. Longer periods of elevated ERC may significantly increase the cost and complexity of fire management activities, requiring new strategies to maintain desired ecological conditions and limit fire risk. Increased fire activity (within the historical range of frequency and severity, and depending on the extent to which ecosystems are adapted) may maintain or restore ecosystem functionality; however, in areas that are highly departed from historical fire regimes or where there is disequilibrium between climate and vegetation, ecosystems may be rapidly and persistently altered by wildfires, especially those that burn under extreme conditions.

Mouse models of neurodegenerative diseases: criteria and general methodology.

PubMed

Janus, Christopher; Welzl, Hans

2010-01-01

The major symptom of Alzheimer's disease is rapidly progressing dementia, coinciding with the formation of amyloid and tau deposits in the central nervous system, and neuronal death. At present familial cases of dementias provide the most promising foundation for modelling neurodegeneration. We describe the mnemonic and other major behavioral symptoms of tauopathies, briefly outline the genetics underlying familiar cases and discuss the arising implications for modelling the disease in mostly transgenic mouse lines. We then depict to what degree the most recent mouse models replicate pathological and cognitive characteristics observed in patients.There is no universally valid behavioral test battery to evaluate mouse models. The selection of individual tests depends on the behavioral and/or memory system in focus, the type of a model and how well it replicates the pathology of a disease and the amount of control over the genetic background of the mouse model. However it is possible to provide guidelines and criteria for modelling the neurodegeneration, setting up the experiments and choosing relevant tests. One should not adopt a "one (trans)gene, one disease" interpretation, but should try to understand how the mouse genome copes with the protein expression of the transgene in question. Further, it is not possible to recommend some mouse models over others since each model is valuable within its own constraints, and the way experiments are performed often reflects the idiosyncratic reality of specific laboratories. Our purpose is to improve bridging molecular and behavioural approaches in translational research.

Stratified turbulent Bunsen flames: flame surface analysis and flame surface density modelling

NASA Astrophysics Data System (ADS)

Ramaekers, W. J. S.; van Oijen, J. A.; de Goey, L. P. H.

2012-12-01

In this paper it is investigated whether the Flame Surface Density (FSD) model, developed for turbulent premixed combustion, is also applicable to stratified flames. Direct Numerical Simulations (DNS) of turbulent stratified Bunsen flames have been carried out, using the Flamelet Generated Manifold (FGM) reduction method for reaction kinetics. Before examining the suitability of the FSD model, flame surfaces are characterized in terms of thickness, curvature and stratification. All flames are in the Thin Reaction Zones regime, and the maximum equivalence ratio range covers 0.1⩽φ⩽1.3. For all flames, local flame thicknesses correspond very well to those observed in stretchless, steady premixed flamelets. Extracted curvature radii and mixing length scales are significantly larger than the flame thickness, implying that the stratified flames all burn in a premixed mode. The remaining challenge is accounting for the large variation in (subfilter) mass burning rate. In this contribution, the FSD model is proven to be applicable for Large Eddy Simulations (LES) of stratified flames for the equivalence ratio range 0.1⩽φ⩽1.3. Subfilter mass burning rate variations are taken into account by a subfilter Probability Density Function (PDF) for the mixture fraction, on which the mass burning rate directly depends. A priori analysis point out that for small stratifications (0.4⩽φ⩽1.0), the replacement of the subfilter PDF (obtained from DNS data) by the corresponding Dirac function is appropriate. Integration of the Dirac function with the mass burning rate m=m(φ), can then adequately model the filtered mass burning rate obtained from filtered DNS data. For a larger stratification (0.1⩽φ⩽1.3), and filter widths up to ten flame thicknesses, a β-function for the subfilter PDF yields substantially better predictions than a Dirac function. Finally, inclusion of a simple algebraic model for the FSD resulted only in small additional deviations from DNS data, thereby rendering this approach promising for application in LES.

Effect of skin graft thickness on scar development in a porcine burn model.

PubMed

DeBruler, Danielle M; Blackstone, Britani N; McFarland, Kevin L; Baumann, Molly E; Supp, Dorothy M; Bailey, J Kevin; Powell, Heather M

2018-06-01

Animal models provide a way to investigate scar therapies in a controlled environment. It is necessary to produce uniform, reproducible scars with high anatomic and biologic similarity to human scars to better evaluate the efficacy of treatment strategies and to develop new treatments. In this study, scar development and maturation were assessed in a porcine full-thickness burn model with immediate excision and split-thickness autograft coverage. Red Duroc pigs were treated with split-thickness autografts of varying thickness: 0.026in. ("thin") or 0.058in. ("thick"). Additionally, the thin skin grafts were meshed and expanded at 1:1.5 or 1:4 to evaluate the role of skin expansion in scar formation. Overall, the burn-excise-autograft model resulted in thick, raised scars. Treatment with thick split-thickness skin grafts resulted in less contraction and reduced scarring as well as improved biomechanics. Thin skin autograft expansion at a 1:4 ratio tended to result in scars that contracted more with increased scar height compared to the 1:1.5 expansion ratio. All treatment groups showed Matrix Metalloproteinase 2 (MMP2) and Transforming Growth Factor β1 (TGF-β1) expression that increased over time and peaked 4 weeks after grafting. Burns treated with thick split-thickness grafts showed decreased expression of pro-inflammatory genes 1 week after grafting, including insulin-like growth factor 1 (IGF-1) and TGF-β1, compared to wounds treated with thin split-thickness grafts. Overall, the burn-excise-autograft model using split-thickness autograft meshed and expanded to 1:1.5 or 1:4, resulted in thick, raised scars similar in appearance and structure to human hypertrophic scars. This model can be used in future studies to study burn treatment outcomes and new therapies. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

North African savanna fires and atmospheric carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iacobellis, S.F.; Frouni, Razafimpaniolo, H.

1994-04-20

The effect of north African savanna fires on atmospheric CO{sub 2} is investigated using a tracer transport model. The model uses winds from operational numerical weather prediction analyses and provides CO{sub 2} concentrations as a function of space and time. After a spin-up period of several years, biomass-burning sources are added, and model experiments are run for an additional year, utilizing various estimates of CO{sub 2} sources. The various model experiments show that biomass burning in the north African savannas significantly affects CO{sub 2} concentrations in South America. The effect is more pronounced during the period from January through March,more » when biomass burning in South America is almost nonexistent. During this period, atmospheric CO{sub 2} concentrations in parts of South America typically may increase by 0.5 to 0.75 ppm at 970 mbar, the average pressure of the lowest model layer. These figures are above the probable uncertainty level, as model runs with biomass-burning sources estimated from independent studies using distinct data sets and techniques indicate. From May through September, when severe biomass burning occurs in South America, the effect of north African savanna fires over South America has become generally small at 970 mbar, but north of the equator it may be of the same magnitude or larger than the effect of South American fires. The CO{sub 2} concentration increase in the extreme northern and southern portions of South America, however, is mostly due to southern African fires, whose effect may be 2-3 times larger than the effect of South American fires at 970 mbar. Even in the central part of the continent, where local biomass-burning emissions are maximum, southern African fires contribute to at least 15% of the CO{sub 2} concentration increase at 970 mbar. 20 refs., 15 figs., 1 tab.« less

Direct comparison of the pharmacodynamics of four antifungal drugs in a mouse model of disseminated candidiasis using microbiological assays of serum drug concentrations.

PubMed

Maki, Katsuyuki; Holmes, Ann R; Watabe, Etsuko; Iguchi, Yumi; Matsumoto, Satoru; Ikeda, Fumiaki; Tawara, Shuichi; Mutoh, Seitaro

2007-01-01

The aim of this study was to compare the pharmacodynamics of the azole antifungal drugs fluconazole, itraconazole and ketoconazole, and the polyene antifungal amphotericin B, in a mouse model of disseminated Candida albicans infection. In order to directly compare effective serum concentrations of these antifungals, drug concentrations were assayed microbiologically by measuring inhibition of C. albicans mycelial growth (mMIC) in a mouse serum-based assay (serum antifungal titer). Efficacy in the mouse infection model was determined using an organ-based (kidney burden) endpoint. For all four drugs, the serum antifungal titers, 8 hr after administration of single doses of drugs at a range of drug concentrations, correlated closely with C. albicans kidney fungal burden in the mouse model. The results showed that determining serum antifungal titer may be used to accurately represent kidney fungal burden in a mouse model of disseminated candidiasis and allowed direct comparison of the pharmacodynamics of differing classes of antifungal drugs.

Evaluating the impact of improvements to the FLAMBE smoke source model on forecasts of aerosol distribution from NAAPS

NASA Astrophysics Data System (ADS)

Hyer, E. J.; Reid, J. S.

2006-12-01

As more forecast models aim to include aerosol and chemical species, there is a need for source functions for biomass burning emissions that are accurate, robust, and operable in real-time. NAAPS is a global aerosol forecast model running every six hours and forecasting distributions of biomass burning, industrial sulfate, dust, and sea salt aerosols. This model is run operationally by the U.S. Navy as an aid to planning. The smoke emissions used as input to the model are calculated from the data collected by the FLAMBE system, driven by near-real-time active fire data from GOES WF_ABBA and MODIS Rapid Response. The smoke source function uses land cover data to predict properties of detected fires based on literature data from experimental burns. This scheme is very sensitive to the choice of land cover data sets. In areas of rapid land cover change, the use of static land cover data can produce artifactual changes in emissions unrelated to real changes in fire patterns. In South America, this change may be as large as 40% over five years. We demonstrate the impact of a modified land cover scheme on FLAMBE emissions and NAAPS forecasts, including a fire size algorithm developed using MODIS burned area data. We also describe the effects of corrections to emissions estimates for cloud and satellite coverage. We outline areas where existing data sources are incomplete and improvements are required to achieve accurate modeling of biomass burning emissions in real time.

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

A trajectory modeling investigation of the biomass burning-tropical ozone relationship

NASA Technical Reports Server (NTRS)

Pickering, Kenneth E.; Thompson, Anne M.; Mcnamara, Donna P.; Schoeberl, Mark R.; Lait, Leslie R.; Newman, Paul A.; Justice, Christopher O.; Kendall, Jacqueline D.

1994-01-01

The hypothesis that tropical total O3 maxima seen by the TOMS satellite derive from African biomass burning has been tested using isentropic trajectory analyses with global meteorological data fields. Two case studies from the 1989 biomass burning season demonstrate that a large fraction of the air arriving at the location of TOMS O3 maxima passed over regions of intense burning. Other trajectories initiated at a series of points over Africa and the Atlantic suggest flight strategies for field studies to be conducted in September 1992.

Differences in Pathogenesis for Salmonella enterica serovar Typhimurium in the Mouse Versus the Swine Model Identify Bacterial Gene Products Required for Systemic but not Gastrointestinal Disease

USDA-ARS?s Scientific Manuscript database

Over the last several decades, the mouse model of Typhoid fever has been an extremely productive model to investigate Salmonella enterica serovar Typhimurium pathogenesis. The mouse is the paradigm for investigating systemic disease due to infection by Salmonella; however, the swine model of gastro...

Inter-Annual Variability of Burned Area in Brazil Based on a Synergistic use of Information Derived from MODIS and Landsat-TM

NASA Astrophysics Data System (ADS)

Libonati, R.; Dacamara, C. C.; Setzer, A. W.; Morelli, F.

2014-12-01

A procedure is presented that allows using information from the MODerate resolution Imaging Spectroradiometer (MODIS) sensor to improve the quality of monthly burned area estimates over Brazil. The method integrates MODIS derived information from two sources; the NASA MCD64A1 Direct Broadcast Monthly Burned Area Product and INPE's Monthly Burned Area MODIS product (AQM-MODIS). The latter product relies on an algorithm that was specifically designed for ecosystems in Brazil, taking advantage of the ability of MIR reflectances to discriminate burned areas. Information from both MODIS products is incorporated by means of a linear regression model where an optimal estimate of the burned area is obtained as a linear combination of burned area estimates from MCD64A1 and AQM-MODIS. The linear regression model is calibrated using as optimal estimates values of burned area derived from Landsat TM during 2005 and 2006 over Jalapão, a region of Cerrado covering an area of 187 x 187 km2. Obtained values of coefficients for MCD64A1 and AQM-MODIS were 0.51 and 0.35, respectively and the root mean square error was 7.6 km2. Robustness of the model was checked by calibrating the model separately for 2005 and 2006 and cross-validating with 2006 and 2005; coefficients for 2005 (2006) were 0.46 (0.54) for MCD64A1 and 0.35 (0.35) for AQM-MODIS and the corresponding root mean square errors for 2006 (2005) were 7.8 (7.4) km2. The linear model was then applied to Brazil as well as to the six Brazilian main biomes, namely Cerrado, Amazônia, Caatinga, Pantanal, Mata Atlântica and Pampa. As to be expected the interannual variability based on the proposed synergistic use of MCD64A1, AQM-MODIS and Landsat Tm data for the period 2005-2010 presents marked differences with the corresponding amounts derived from MCD64A1 alone. For instance during the considered period, values (in 103 km2) from the proposed approach (from MCD64A1) are 399 (142), 232 (62), 559 (259), 274 (73), 219 (31) and 415 (251). Values obtained with the proposed approach may be viewed as an improved alternative to the currently available products over Brazil.

Cognition in patients with burn injury in the inpatient rehabilitation population.

PubMed

Purohit, Maulik; Goldstein, Richard; Nadler, Deborah; Mathews, Katie; Slocum, Chloe; Gerrard, Paul; DiVita, Margaret A; Ryan, Colleen M; Zafonte, Ross; Kowalske, Karen; Schneider, Jeffrey C

2014-07-01

To analyze potential cognitive impairment in patients with burn injury in the inpatient rehabilitation population. Rehabilitation patients with burn injury were compared with the following impairment groups: spinal cord injury, amputation, polytrauma and multiple fractures, and hip replacement. Differences between the groups were calculated for each cognitive subscale item and total cognitive FIM. Patients with burn injury were compared with the other groups using a bivariate linear regression model. A multivariable linear regression model was used to determine whether differences in cognition existed after adjusting for covariates (eg, sociodemographic factors, facility factors, medical complications) based on previous studies. Inpatient rehabilitation facilities. Data from Uniform Data System for Medical Rehabilitation from 2002 to 2011 for adults with burn injury (N=5347) were compared with other rehabilitation populations (N=668,816). Not applicable. Comparison of total cognitive FIM scores and subscales (memory, verbal comprehension, verbal expression, social interaction, problem solving) for patients with burn injury versus other rehabilitation populations. Adults with burn injuries had an average total cognitive FIM score ± SD of 26.8±7.0 compared with an average FIM score ± SD of 28.7±6.0 for the other groups combined (P<.001). The subscale with the greatest difference between those with burn injury and the other groups was memory (5.1±1.7 compared with 5.6±1.5, P<.001). These differences persisted after adjustment for covariates. Adults with burn injury have worse cognitive FIM scores than other rehabilitation populations. Future research is needed to determine the impact of this comorbidity on patient outcomes and potential interventions for these deficits. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

The effect of preexisting respiratory co-morbidities on burn outcomes☆

PubMed Central

Knowlin, Laquanda T.; Stanford, Lindsay B.; Cairns, Bruce A.; Charles, Anthony G.

2018-01-01

Introduction Burns cause physiologic changes in multiple organ systems in the body. Burn mortality is usually attributable to pulmonary complications, which can occur in up to 41% of patients admitted to the hospital after burn. Patients with preexisting comorbidities such as chronic lung diseases may be more susceptible. We therefore sought to examine the impact of preexisting respiratory disease on burn outcomes. Methods A retrospective analysis of patients admitted to a regional burn center from 2002–2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA, pre-existing comorbidities, smoker status, length of hospital stay, and days of mechanical ventilation. Bivariate analysis was performed and Cox regression modeling using significant variables was utilized to estimate hazard of progression to mechanical ventilation and mortality. Results There were a total of 7640 patients over the study period. Overall survival rate was 96%. 8% (n=672) had a preexisting respiratory disease. Chronic lung disease patients had a higher mortality rate (7%) compared to those without lung disease (4%, p<0.01). The adjusted Cox regression model to estimate the hazard of progression to mechanical ventilation in patients with respiratory disease was 21% higher compared to those without respiratory disease (HR=1.21, 95% CI=1.01–1.44). The hazard of progression to mortality is 56% higher (HR=1.56, 95% CI=1.10–2.19) for patients with pre-existing respiratory disease compared to those without respiratory disease after controlling for patient demographics and injury characteristics. Conclusion Preexisting chronic respiratory disease significantly increases the hazard of progression to mechanical ventilation and mortality in patients following burn. Given the increasing number of Americans with chronic respiratory diseases, there will likely be a greater number of individuals at risk for worse outcomes following burn. PMID:28341260

The effect of preexisting respiratory co-morbidities on burn outcomes.

PubMed

Knowlin, Laquanda T; Stanford, Lindsay B; Cairns, Bruce A; Charles, Anthony G

2017-03-01

Burns cause physiologic changes in multiple organ systems in the body. Burn mortality is usually attributable to pulmonary complications, which can occur in up to 41% of patients admitted to the hospital after burn. Patients with preexisting comorbidities such as chronic lung diseases may be more susceptible. We therefore sought to examine the impact of preexisting respiratory disease on burn outcomes. A retrospective analysis of patients admitted to a regional burn center from 2002-2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA, pre-existing comorbidities, smoker status, length of hospital stay, and days of mechanical ventilation. Bivariate analysis was performed and Cox regression modeling using significant variables was utilized to estimate hazard of progression to mechanical ventilation and mortality. There were a total of 7640 patients over the study period. Overall survival rate was 96%. 8% (n=672) had a preexisting respiratory disease. Chronic lung disease patients had a higher mortality rate (7%) compared to those without lung disease (4%, p<0.01). The adjusted Cox regression model to estimate the hazard of progression to mechanical ventilation in patients with respiratory disease was 21% higher compared to those without respiratory disease (HR=1.21, 95% CI=1.01-1.44). The hazard of progression to mortality is 56% higher (HR=1.56, 95% CI=1.10-2.19) for patients with pre-existing respiratory disease compared to those without respiratory disease after controlling for patient demographics and injury characteristics. Preexisting chronic respiratory disease significantly increases the hazard of progression to mechanical ventilation and mortality in patients following burn. Given the increasing number of Americans with chronic respiratory diseases, there will likely be a greater number of individuals at risk for worse outcomes following burn. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Burn mortality in patients with preexisting cardiovascular disease.

PubMed

Knowlin, Laquanda; Reid, Trista; Williams, Felicia; Cairns, Bruce; Charles, Anthony

2017-08-01

Burn shock, a complex process, which develops following burn leads to severe and unique derangement of cardiovascular function. Patients with preexisting comorbidities such as cardiovascular diseases may be more susceptible. We therefore sought to examine the impact of preexisting cardiovascular disease on burn outcomes. A retrospective analysis of patients admitted to a regional burn center from 2002 to 2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA, pre-existing comorbidities, and length of ICU/hospital stay. Bivariate analysis was performed and Poisson regression modeling was utilized to estimate the incidence of being in the ICU and mortality. There were a total of 5332 adult patients admitted over the study period. 6% (n=428) had a preexisting cardiovascular disease. Cardiovascular disease patients had a higher mortality rate (16%) compared to those without cardiovascular disease (3%, p<0.001). The adjusted Poisson regression model to estimate incidence risk of being in intensive care unit in patients with cardiovascular disease was 33% higher compared to those without cardiovascular disease (IRR=1.33, 95% CI=1.22-1.47). The risk for mortality is 42% higher (IRR=1.42, 95% CI=1.10-1.84) for patients with pre-existing cardiovascular disease compared to those without cardiovascular disease after controlling for other covariates. Preexisting cardiovascular disease significantly increases the risk of intensive care unit admission and mortality in burn patients. Given the increasing number of Americans with cardiovascular diseases, there will likely be a greater number of individuals at risk for worse outcomes following burn. This knowledge can help with burn prognostication. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Data Filtering of Western Hemisphere GOES Wildfire ABBA Products

NASA Astrophysics Data System (ADS)

Theisen, M.; Prins, E.; Schmidt, C.; Reid, J. S.; Hunter, J.; Westphal, D.

2002-05-01

The Fire Locating and Modeling of Burning Emissions (FLAMBE') project was developed to model biomass burning emissions, transport, and radiative effects in real time. The model relies on data from the Geostationary Operational Environment Satellites (GOES-8, GOES-10), that is generated by the Wildfire Automated Biomass Burning Algorithm (WF ABBA). In an attempt to develop the most accurate modeling system the data set needs to be filtered to distinguish the true fire pixels from false alarms. False alarms occur due to reflection of solar radiation off of standing water, surface structure variances, and heat anomalies. The Reoccurring Fire Filtering algorithm (ReFF) was developed to address such false alarms by filtering data dependent on reoccurrence, location in relation to region and satellite, as well as heat intensity. WF ABBA data for the year 2000 during the peak of the burning season were analyzed using ReFF. The analysis resulted in a 45% decrease in North America and only a 15% decrease in South America, respectively, in total fire pixel occurrence. The lower percentage decrease in South America is a result of fires burning for longer periods of time, less surface variance, as well as an increase in heat intensity of fires for that region. Also fires are so prevalent in the region that multiple fires may coexist in the same 4-kilometer pixel.

Impact of facial burns: relationship between depressive symptoms, self-esteem and scar severity.

PubMed

Hoogewerf, Cornelis Johannes; van Baar, Margriet Elisabeth; Middelkoop, Esther; van Loey, Nancy Elisa

2014-01-01

This study assessed the role of self-reported facial scar severity as a possible influencing factor on self-esteem and depressive symptoms in patients with facial burns. A prospective multicentre cohort study with a 6 months follow-up was conducted including 132 patients with facial burns. Patients completed the Patient and Observer Scar Assessment Scale, the Rosenberg Self-esteem Scale and the Hospital Anxiety and Depression Scale. Structural Equation Modeling was used to assess the relations between depressive symptoms, self-esteem and scar severity. The model showed that patient-rated facial scar severity was not predictive for self-esteem and depressive symptoms six months post-burn. There was, however, a significant relationship between early depressive symptoms and both patient-rated facial scar severity and subsequent self-esteem. The variables in the model accounted for 37% of the variance in depressive symptoms six months post-burn and the model provided a moderately well-fitting representation of the data. The study suggests that self-esteem and depressive symptoms were not affected by self-reported facial scar severity but that earlier depressive symptoms were indicative for a more severe self-reported facial scar rating. Therefore, routine psychological screening during hospitalisation is recommended in order to identify patients at risk and to optimise their treatment. Copyright © 2014 Elsevier Inc. All rights reserved.

Biomass burning losses of carbon estimated from ecosystem modeling and satellite data analysis for the Brazilian Amazon region

NASA Astrophysics Data System (ADS)

Potter, Christopher; Brooks Genovese, Vanessa; Klooster, Steven; Bobo, Matthew; Torregrosa, Alicia

To produce a new daily record of gross carbon emissions from biomass burning events and post-burning decomposition fluxes in the states of the Brazilian Legal Amazon (Instituto Brasileiro de Geografia e Estatistica (IBGE), 1991. Anuario Estatistico do Brasil, Vol. 51. Rio de Janeiro, Brazil pp. 1-1024). We have used vegetation greenness estimates from satellite images as inputs to a terrestrial ecosystem production model. This carbon allocation model generates new estimates of regional aboveground vegetation biomass at 8-km resolution. The modeled biomass product is then combined for the first time with fire pixel counts from the advanced very high-resolution radiometer (AVHRR) to overlay regional burning activities in the Amazon. Results from our analysis indicate that carbon emission estimates from annual region-wide sources of deforestation and biomass burning in the early 1990s are apparently three to five times higher than reported in previous studies for the Brazilian Legal Amazon (Houghton et al., 2000. Nature 403, 301-304; Fearnside, 1997. Climatic Change 35, 321-360), i.e., studies which implied that the Legal Amazon region tends toward a net-zero annual source of terrestrial carbon. In contrast, our analysis implies that the total source fluxes over the entire Legal Amazon region range from 0.2 to 1.2 Pg C yr -1, depending strongly on annual rainfall patterns. The reasons for our higher burning emission estimates are (1) use of combustion fractions typically measured during Amazon forest burning events for computing carbon losses, (2) more detailed geographic distribution of vegetation biomass and daily fire activity for the region, and (3) inclusion of fire effects in extensive areas of the Legal Amazon covered by open woodland, secondary forests, savanna, and pasture vegetation. The total area of rainforest estimated annually to be deforested did not differ substantially among the previous analyses cited and our own.

A unified model of the excitability of mouse sensory and motor axons.

PubMed

Makker, Preet G S; Matamala, José Manuel; Park, Susanna B; Lees, Justin G; Kiernan, Matthew C; Burke, David; Moalem-Taylor, Gila; Howells, James

2018-06-19

Non-invasive nerve excitability techniques have provided valuable insight into the understanding of neurological disorders. The widespread use of mice in translational research on peripheral nerve disorders and by pharmaceutical companies during drug development requires valid and reliable models that can be compared to humans. This study established a novel experimental protocol that enables comparative assessment of the excitability properties of motor and sensory axons at the same site in mouse caudal nerve, compared the mouse data to data for motor and sensory axons in human median nerve at the wrist, and constructed a mathematical model of the excitability of mouse axons. In a separate study, ischaemia was employed as an experimental manoeuvre to test the translational utility of this preparation. The patterns of mouse sensory and motor excitability were qualitatively similar to human studies under normal and ischaemic conditions. The most conspicuous differences between mouse and human studies were observed in the recovery cycle and the response to hyperpolarization. Modelling showed that an increase in temperature in mouse axons could account for most of the differences in the recovery cycle. The modelling also suggested a larger hyperpolarization-activated conductance in mouse axons. The kinetics of this conductance appeared to be much slower raising the possibility that an additional or different hyperpolarization-activated cyclic-nucleotide gated (HCN) channel isoform underlies the accommodation to hyperpolarization in mouse axons. Given a possible difference in HCN isoforms, caution should be exercised in extrapolating from studies of mouse motor and sensory axons to human nerve disorders. This article is protected by copyright. All rights reserved.

Rapamycin improves sociability in the BTBR T(+)Itpr3(tf)/J mouse model of autism spectrum disorders.

PubMed

Burket, Jessica A; Benson, Andrew D; Tang, Amy H; Deutsch, Stephen I

2014-01-01

Overactivation of the mammalian target of rapamycin (mTOR) has been implicated in the pathogenesis of syndromic forms of autism spectrum disorders (ASDs), such as tuberous sclerosis complex, neurofibromatosis 1, and fragile X syndrome. Administration of mTORC1 (mTOR complex 1) inhibitors (e.g. rapamycin) in syndromic mouse models of ASDs improved behavior, cognition, and neuropathology. However, since only a minority of ASDs are due to the effects of single genes (∼10%), there is a need to explore inhibition of mTOR activity in mouse models that may be more relevant to the majority of nonsyndromic presentations, such as the genetically inbred BTBR T(+)Itpr3(tf)/J (BTBR) mouse model of ASDs. BTBR mice have social impairment and exhibit increased stereotypic behavior. In prior work, d-cycloserine, a partial glycineB site agonist that targets the N-methyl-d-aspartate (NMDA) receptor, was shown to improve sociability in both Balb/c and BTBR mouse models of ASDs. Importantly, NMDA receptor activation regulates mTOR signaling activity. The current study investigated the ability of rapamycin (10mg/kg, i.p.×four days), an mTORC1 inhibitor, to improve sociability and stereotypic behavior in BTBR mice. Using a standard paradigm to assess mouse social behavior, rapamycin improved several measures of sociability in the BTBR mouse, suggesting that mTOR overactivation represents a therapeutic target that mediates or contributes to impaired sociability in the BTBR mouse model of ASDs. Interestingly, there was no effect of rapamycin on stereotypic behaviors in this mouse model. Copyright © 2013 Elsevier Inc. All rights reserved.

Progress in the development of the MARBLE platform for studying thermonuclear burn in the presence of heterogeneous mix on OMEGA and the National Ignition Facility

NASA Astrophysics Data System (ADS)

Murphy, T. J.; Douglas, M. R.; Fincke, J. R.; Olson, R. E.; Cobble, J. A.; Haines, B. M.; Hamilton, C. E.; Lee, M. N.; Oertel, J. A.; Parra-Vasquez, N. A. G.; Randolph, R. B.; Schmidt, D. W.; Shah, R. C.; Smidt, J. M.; Tregillis, I. L.

2016-05-01

Mix of ablator material into fuel of an ICF capsule adds non-burning material, diluting the fuel and reducing burn. The amount of the reduction is dependent in part on the morphology of the mix. A probability distribution function (PDF) burn model has been developed [6] that utilizes the average concentration of mixed materials as well as the variance in this quantity across cells provided by the BHR turbulent transport model [3] and its revisions [4] to describe the mix in terms of a PDF of concentrations of fuel and ablator material, and provides the burn rate in mixed material. Work is underway to develop the MARBLE ICF platform for use on the National Ignition Facility in experiments to quantify the influence of heterogeneous mix on fusion burn. This platform consists of a plastic (CH) capsule filled with a deuterated plastic foam (CD) with a density of a few tens of milligrams per cubic centimeter, with tritium gas filling the voids in the foam. This capsule will be driven using x-ray drive on NIF, and the resulting shocks will induce turbulent mix that will result in the mixing of deuterium from the foam with the tritium gas. In order to affect the morphology of the mix, engineered foams with voids of diameter up to 100 microns will be utilized. The degree of mix will be determined from the ratio of DT to DD neutron yield. As the mix increases, the yield from reactions between the deuterium of the CD foam with tritium from the gas will increase. The ratio of DT to DD neutrons will be compared to a variation of the PDF burn model that quantifies reactions from initially separated reactants.

Care of the Critically Ill Burn Patient. An Overview from the Perspective of Optimizing Palliative Care.

PubMed

Ray, Daniel E; Karlekar, Mohana B; Crouse, Donnelle L; Campbell, Margaret; Curtis, J Randall; Edwards, Jeffrey; Frontera, Jennifer; Lustbader, Dana R; Mosenthal, Anne C; Mulkerin, Colleen; Puntillo, Kathleen A; Weissman, David E; Boss, Renee D; Brasel, Karen J; Nelson, Judith E

2017-07-01

Burn specialists have long recognized the need for and have role modeled a comprehensive approach incorporating relief of distress as part of care during critical illness. More recently, palliative care specialists have become part of the healthcare team in many U.S. hospitals, especially larger academic institutions that are more likely to have designated burn centers. No current literature describes the intersection of palliative care and burn care or integration of primary and specialist palliative care in this unique context. This Perspective gives an overview of burn care; focuses on pain and other symptoms in burn intensive care unit settings; addresses special needs of critically ill burned patients, their families, and clinicians for high-quality palliative care; and highlights potential benefits of integrating primary and specialist palliative care in burn critical care. MEDLINE and the Cumulative Index to Nursing and Allied Health Literature were searched, and an e-mail survey was used to obtain information from U.S. Burn Fellowship Program directors about palliative medicine training. The Improving Palliative Care in the Intensive Care Unit Project Advisory Board synthesized published evidence with their own research and clinical experience in preparing this article. Mortality and severe morbidity for critically ill burned patients remains high. American Burn Association guidelines lay the foundation for a robust system of palliative care delivery, embedding palliative care principles and processes in intensive care by burn providers. Understanding basic burn care, challenges for symptom management and communication, and the culture of the particular burn unit, can optimize quality and integration of primary and specialist palliative care in this distinctive setting.

In Vivo Hyperthermic Stress Model: An Easy Tool to Study the Effects of Oxidative Stress on Neuronal Tau Functionality in Mouse Brain.

PubMed

Chauderlier, Alban; Delattre, Lucie; Buée, Luc; Galas, Marie-Christine

2017-01-01

Oxidative damage is an early event in neurodegenerative disorders such as Alzheimer disease. To increase oxidative stress in AD-related mouse models is essential to study early mechanisms involved in the physiopathology of these diseases. In this chapter, we describe an experimental mouse model of transient and acute hyperthermic stress to induce in vivo an increase of oxidative stress in the brain of any kind of wild-type or transgenic mouse.

Glutamine with probiotics attenuates intestinal inflammation and oxidative stress in a rat burn injury model through altered iNOS gene aberrant methylation

PubMed Central

Gong, Zhen-Yu; Yuan, Zhi-Qiang; Dong, Zhi-Wei; Peng, Yi-Zhi

2017-01-01

Severe burns may lead to intestinal inflammation and oxidative stress resulting in intestinal barrier damage and gut dysfunction. In the management of severe burns, therapies are needed to attenuate whole-body inflammatory responses and control the burden of oxidative stress. In this study, we evaluated the effects of oral glutamine (Gln) with probiotics on burn-induced intestinal inflammation and oxidative stress using a Wistar rat burn injury model. We then explored potential molecular mechanisms for the effects of glutamine and probiotics on intestinal tissue inflammation and oxidative stress. We found that glutamine and probiotics together significantly inhibited nitric oxide (NO) content; reduced levels of the inflammatory factors TNF-α, IL-6, and IL-8; and altered expression of oxidative stress factors including reactive oxygen species and superoxide dismutase. We found that the apoptotic proportion of intestinal epithelial cells in severely burned subjects was notably decreased following treatment with glutamine plus probiotics. We also found that glutamine and probiotics given together markedly reduced NO content by down-regulating the expression of iNOS in blood and intestinal tissue. These findings indicate that regulation of the iNOS gene plays a pivotal role in inflammation and oxidative stress in the response to severe burns in the Wistar rat. We then further investigated the mechanism by which combined therapy with glutamine and probiotics might reduce expression of iNOS and found that this treatment resulted in increased methylation of the iNOS gene. The methylation level of the iNOS gene was found to be regulated via differential expression of DNMT1 and Tet1. Collectively, our results suggest that combined therapy with glutamine and probiotics can markedly reduce the synthesis of NO, suppressing intestinal inflammation and oxidative stress in the Wistar rat burn injury model. PMID:28560003

Design of a model to predict surge capacity bottlenecks for burn mass casualties at a large academic medical center.

PubMed

Abir, Mahshid; Davis, Matthew M; Sankar, Pratap; Wong, Andrew C; Wang, Stewart C

2013-02-01

To design and test a model to predict surge capacity bottlenecks at a large academic medical center in response to a mass-casualty incident (MCI) involving multiple burn victims. Using the simulation software ProModel, a model of patient flow and anticipated resource use, according to principles of disaster management, was developed based upon historical data from the University Hospital of the University of Michigan Health System. Model inputs included: (a) age and weight distribution for casualties, and distribution of size and depth of burns; (b) rate of arrival of casualties to the hospital, and triage to ward or critical care settings; (c) eligibility for early discharge of non-MCI inpatients at time of MCI; (d) baseline occupancy of intensive care unit (ICU), surgical step-down, and ward; (e) staff availability-number of physicians, nurses, and respiratory therapists, and the expected ratio of each group to patients; (f) floor and operating room resources-anticipating the need for mechanical ventilators, burn care and surgical resources, blood products, and intravenous fluids; (g) average hospital length of stay and mortality rate for patients with inhalation injury and different size burns; and (h) average number of times that different size burns undergo surgery. Key model outputs include time to bottleneck for each limiting resource and average waiting time to hospital bed availability. Given base-case model assumptions (including 100 mass casualties with an inter-arrival rate to the hospital of one patient every three minutes), hospital utilization is constrained within the first 120 minutes to 21 casualties, due to the limited number of beds. The first bottleneck is attributable to exhausting critical care beds, followed by floor beds. Given this limitation in number of patients, the temporal order of the ensuing bottlenecks is as follows: Lactated Ringer's solution (4 h), silver sulfadiazine/Silvadene (6 h), albumin (48 h), thrombin topical (72 h), type AB packed red blood cells (76 h), silver dressing/Acticoat (100 h), bismuth tribromophenate/Xeroform (102 h), and gauze bandage rolls/Kerlix (168 h). The following items do not precipitate a bottleneck: ventilators, topical epinephrine, staplers, foams, antimicrobial non-adherent dressing/Telfa types A, B, or O blood. Nurse, respiratory therapist, and physician staffing does not induce bottlenecks. This model, and similar models for non-burn-related MCIs, can serve as a real-time estimation and management tool for hospital capacity in the setting of MCIs, and can inform supply decision support for disaster management.

The influence of boreal biomass burning emissions on the distribution of tropospheric ozone over North America and the North Atlantic during 2010

NASA Astrophysics Data System (ADS)

Parrington, M.; Palmer, P. I.; Henze, D. K.; Tarasick, D. W.; Hyer, E. J.; Owen, R. C.; Helmig, D.; Clerbaux, C.; Bowman, K. W.; Deeter, M. N.; Barratt, E. M.; Coheur, P.-F.; Hurtmans, D.; Jiang, Z.; George, M.; Worden, J. R.

2012-02-01

We have analysed the sensitivity of the tropospheric ozone distribution over North America and the North Atlantic to boreal biomass burning emissions during the summer of 2010 using the GEOS-Chem 3-D global tropospheric chemical transport model and observations from in situ and satellite instruments. We show that the model ozone distribution is consistent with observations from the Pico Mountain Observatory in the Azores, ozonesondes across Canada, and the Tropospheric Emission Spectrometer (TES) and Infrared Atmospheric Sounding Instrument (IASI) satellite instruments. Mean biases between the model and observed ozone mixing ratio in the free troposphere were less than 10 ppbv. We used the adjoint of GEOS-Chem to show the model ozone distribution in the free troposphere over Maritime Canada is largely sensitive to NOx emissions from biomass burning sources in Central Canada, lightning sources in the central US, and anthropogenic sources in the eastern US and south-eastern Canada. We also used the adjoint of GEOS-Chem to evaluate the Fire Locating And Monitoring of Burning Emissions (FLAMBE) inventory through assimilation of CO observations from the Measurements Of Pollution In The Troposphere (MOPITT) satellite instrument. The CO inversion showed that, on average, the FLAMBE emissions needed to be reduced to 89% of their original values, with scaling factors ranging from 12% to 102%, to fit the MOPITT observations in the boreal regions. Applying the CO scaling factors to all species emitted from boreal biomass burning sources led to a decrease of the model tropospheric distributions of CO, PAN, and NOx by as much as -20 ppbv, -50 pptv, and -20 pptv respectively. The modification of the biomass burning emission estimates reduced the model ozone distribution by approximately -3 ppbv (-8%) and on average improved the agreement of the model ozone distribution compared to the observations throughout the free troposphere, reducing the mean model bias from 5.5 to 4.0 ppbv for the Pico Mountain Observatory, 3.0 to 0.9 ppbv for ozonesondes, 2.0 to 0.9 ppbv for TES, and 2.8 to 1.4 ppbv for IASI.

The Aerosol Models in MODTRAN: Incorporating Selected Measurements From Northern Australia

DTIC Science & Technology

2005-12-01

biomass burning smoke aerosol is modelled assuming the particles are spherical and Mie scattering theory is used to calculate the extinction and...and therefore internally mixed aerosol particles are hygroscopic . Shettle and Fenn model the growth in the size of aerosol particles and changes in...by Sutherland and Khanna [21] was to obtain measurements of the optical properties of organic -based aerosols produced by burning vegetation.

Modelling Carbon Emissions in Calluna vulgaris-Dominated Ecosystems when Prescribed Burning and Wildfires Interact.

PubMed

Santana, Victor M; Alday, Josu G; Lee, HyoHyeMi; Allen, Katherine A; Marrs, Rob H

2016-01-01

A present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we modeled the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north-south gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads and annual C emissions under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with a decreasing wildfire return intervals. We observed that litter accumulation patterns varied between sites. Northern sites (colder and wetter) accumulated lower amounts of litter with time than southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon emissions also differed between sites: the optimal rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for minimum C emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C emissions.

Estimating the time and temperature relationship for causation of deep-partial thickness skin burns.

PubMed

Abraham, John P; Plourde, Brian; Vallez, Lauren; Stark, John; Diller, Kenneth R

2015-12-01

The objective of this study is to develop and present a simple procedure for evaluating the temperature and exposure-time conditions that lead to causation of a deep-partial thickness burn and the effect that the immediate post-burn thermal environment can have on the process. A computational model has been designed and applied to predict the time required for skin burns to reach a deep-partial thickness level of injury. The model includes multiple tissue layers including the epidermis, dermis, hypodermis, and subcutaneous tissue. Simulated exposure temperatures ranged from 62.8 to 87.8°C (145-190°F). Two scenarios were investigated. The first and worst case scenario was a direct exposure to water (characterized by a large convection coefficient) with the clothing left on the skin following the exposure. A second case consisted of a scald insult followed immediately by the skin being washed with cool water (20°C). For both cases, an Arrhenius injury model was applied whereby the extent and depth of injury were calculated and compared for the different post-burn treatments. In addition, injury values were compared with experiment data from the literature to assess verification of the numerical methodology. It was found that the clinical observations of injury extent agreed with the calculated values. Furthermore, inundation with cool water decreased skin temperatures more quickly than the clothing insulating case and led to a modest decrease in the burn extent. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

What Fraction of Global Fire Activity Can Be Forecast Using Sea Surface Temperatures?

NASA Astrophysics Data System (ADS)

Chen, Y.; Randerson, J. T.; Morton, D. C.; Andela, N.; Giglio, L.

2015-12-01

Variations in sea surface temperatures (SSTs) can influence climate dynamics in local and remote land areas, and thus influence fire-climate interactions that govern burned area. SST information has been recently used in statistical models to create seasonal outlooks of fire season severity in South America and as the initial condition for dynamical model predictions of fire activity in Indonesia. However, the degree to which large-scale ocean-atmosphere interactions can influence burned area in other continental regions has not been systematically explored. Here we quantified the amount of global burned area that can be predicted using SSTs in 14 different oceans regions as statistical predictors. We first examined lagged correlations between GFED4s burned area and the 14 ocean climate indices (OCIs) individually. The maximum correlations from different OCIs were used to construct a global map of fire predictability. About half of the global burned area can be forecast by this approach 3 months before the peak burning month (with a Pearson's r of 0.5 or higher), with the highest levels of predictability in Central America and Equatorial Asia. Several hotspots of predictability were identified using k-means cluster analysis. Within these regions, we tested the improvements of the forecast by using two OCIs from different oceans. Our forecast models were based on near-real-time SST data and may therefore support the development of new seasonal outlooks for fire activity that can aid the sustainable management of these fire-prone ecosystems.

Landsat-Based Detection and Severity Analysis of Burned Sugarcane Plots in Tarlac, Philippines Using Differenced Normalized Burn Ratio (dNBR)

NASA Astrophysics Data System (ADS)

Baloloy, A. B.; Blanco, A. C.; Gana, B. S.; Sta. Ana, R. C.; Olalia, L. C.

2016-09-01

The Philippines has a booming sugarcane industry contributing about PHP 70 billion annually to the local economy through raw sugar, molasses and bioethanol production (SRA, 2012). Sugarcane planters adapt different farm practices in cultivating sugarcane, one of which is cane burning to eliminate unwanted plant material and facilitate easier harvest. Information on burned sugarcane extent is significant in yield estimation models to calculate total sugar lost during harvest. Pre-harvest burning can lessen sucrose by 2.7% - 5% of the potential yield (Gomez, et al 2006; Hiranyavasit, 2016). This study employs a method for detecting burn sugarcane area and determining burn severity through Differenced Normalized Burn Ratio (dNBR) using Landsat 8 Images acquired during the late milling season in Tarlac, Philippines. Total burned area was computed per burn severity based on pre-fire and post-fire images. Results show that 75.38% of the total sugarcane fields in Tarlac were burned with post-fire regrowth; 16.61% were recently burned; and only 8.01% were unburned. The monthly dNBR for February to March generated the largest area with low severity burn (1,436 ha) and high severity burn (31.14 ha) due to pre-harvest burning. Post-fire regrowth is highest in April to May when previously burned areas were already replanted with sugarcane. The maximum dNBR of the entire late milling season (February to May) recorded larger extent of areas with high and low post-fire regrowth compared to areas with low, moderate and high burn severity. Normalized Difference Vegetation Index (NDVI) was used to analyse vegetation dynamics between the burn severity classes. Significant positive correlation, rho = 0.99, was observed between dNBR and dNDVI at 5% level (p = 0.004). An accuracy of 89.03% was calculated for the Landsat-derived NBR validated using actual mill data for crop year 2015-2016.

Dredge-up and Envelope Burning in Intermediate-Mass Giants of Very Low Metallicity

NASA Astrophysics Data System (ADS)

Herwig, Falk

2004-04-01

The evolution of intermediate-mass stars at very low metallicity during their final thermal pulse asymptotic giant branch (AGB) phase is studied in detail. As representative examples, models with initial masses of 4 and 5Msolar and with a metallicity of Z=0.0001 ([Fe/H]~-2.3) are discussed. The one-dimensional stellar structure and evolution model includes time- and depth-dependent overshooting motivated by hydrodynamic simulations, as well as a full nuclear network and time-dependent mixing. Particular attention is given to high time and space resolution to avoid numerical artifacts related to third dredge-up and hot bottom burning predictions. The model calculations predict very efficient third dredge-up that mixes the envelope with the entire intershell layer or a large fraction thereof and in some cases penetrates into the C/O core below the He shell. In all cases primary oxygen is mixed into the envelope. The models predict efficient envelope burning during the interpulse phase. Depending on the envelope-burning temperature, oxygen is destroyed to varying degrees. The combined effect of dredge-up and envelope burning does not lead to any significant oxygen depletion in any of the cases considered in this study. The large dredge-up efficiency in our model is closely related to the particular properties of the H shell during the dredge-up phase in low-metallicity very metal-poor stars, which is followed here over many thermal pulses. During the dredge-up phase, the temperature just below the convective boundary is large enough for protons to burn vigorously when they are brought into the C-rich environment below the convection boundary by the time- and depth-dependent overshooting. H-burning luminosities of 105 to ~2×106Lsolar are generated. C, and to lesser degree O, is transformed into N in this dredge-up overshooting layer and enters the envelope. The global effect on the CNO abundance is similar to that of hot bottom burning. If the overshoot efficiency is larger, then dredge-up H burning causes a further increase in the dredge-up efficiency. After some thermal pulses, the dredge-up proceeds through the He shell and into the CO core beneath. Then neutrons may not be released from 13C in radiative conditions during the interpulse phase because of the scarcity of α-particles for the 13C(α,n)16O reactions. Conditions for the s-process are discussed qualitatively. The abundance evolution of H, He, C, N, O, and Na is described. Finally, the model predictions for sodium and oxygen are compared with observed abundances. The notion that massive AGB stars are the origin of the O-Na abundance anticorrelation in globular cluster giants is not consistent with the model predictions of this study. The abundance of the C-rich extremely metal-poor binaries LP 625-44, CS 29497-030, and HE 0024-2523 is discussed.

Muscle Contractile Properties in Severely Burned Rats

DTIC Science & Technology

2010-01-01

slow - twitch muscles such as sloeus (data not shown). In rats, the TA contains predominantly fast ...Hasselgren PO. The molecular regulation of protein breakdown following burn injury is different in fast - and slow - twitch skeletal muscle . Int J Mol Med 1998;1...burn model, it was reported that only fast muscle fibers are affected and slow muscle fibers were mostly preserved [30–32]. We found similar results

Burning rate of solid wood measured in a heat release rate calorimeter

Treesearch

H. C. Tran; R. H. White

1992-01-01

Burning rate is a key factor in modeling fire growth and fire endurance of wood structures. This study investigated the burning rate of selected wood materials as determined by heat release, mass loss and charring rates. Thick samples of redwood, southern pine, red oak and basswood were tested in a heat release rate calorimeter. Results on ignitability and average beat...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2013 CFR

2013-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2014 CFR

2014-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2012 CFR

2012-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2010 CFR

2010-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

40 CFR 60.3069 - Am I required to apply for and obtain a title V operating permit for my air curtain incinerator...

Code of Federal Regulations, 2011 CFR

2011-07-01

... title V operating permit for my air curtain incinerator that burns only wood waste, clean lumber, and... December 9, 2004 Model Rule-Air Curtain Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard... incinerator that burns only wood waste, clean lumber, and yard waste? Yes, if your air curtain incinerator is...

Implementation of a manual for working with wobbler mice and criteria for discontinuation of the experiment.

PubMed

Ott, Bastian; Dahlke, Carolin; Meller, Karl; Napirei, Markus; Schmitt-John, Thomas; Brand-Saberi, Beate; Theiss, Carsten; Saberi, Darius

2015-07-01

Mouse breeding is of importance to a whole range of medical and biological research. There are many known mouse models for motor neuron diseases. However, it must be kept in mind that especially mouse models for amyotrophic lateral sclerosis develop severe symptoms causing intense stress. This article is designed to summarize conscientious work with the wobbler mouse, a model for the sporadic form of amyotrophic lateral sclerosis. This mouse model is characterized by a degeneration of α-motor-neurons leading to head tremor, loss of body weight and rapidly progressive paralysis. Although this mouse model has been known since 1956, there are no guidelines for breeding wobbler mice. Due to the lack of such guidelines the present study tries to close this gap and implements a manual for further studies. It includes the whole workflow in regard to wobbler mice from breeding and animal care taking, genotyping and phenotype analysis, but also gives some examples for the use of various neuronal tissues for histological investigation. Beside the progress in research a second aim should always be the enhancement of mouse welfare and reduction of stress for the laboratory animals. Copyright © 2015 Elsevier GmbH. All rights reserved.

The effect of smoking status on burn inhalation injury mortality.

PubMed

Knowlin, Laquanda; Stanford, Lindsay; Cairns, Bruce; Charles, Anthony

2017-05-01

Three factors that effect burn mortality are age, total body surface of burn (TBSA), and inhalation injury. Of the three, inhalation injury is the strongest predictor of mortality thus its inclusion in the revised Baux score (age+TBSA+17* (inhalation injury, 1=yes, 0=no)). However, the weighted contribution of specific comorbidities such as smoker status on mortality has traditionally not been accounted for nor studied in this subset of burn patients. We therefore sought to examine the impact of current tobacco and/or marijuana smoking in patients with inhalation injury. A retrospective analysis of patients admitted to a regional burn center from 2002 to 2012. Independent variables analyzed included basic demographics, burn mechanism, presence of inhalation injury, TBSA, pre-existing comorbidities, and smoker status. Bivariate analysis was performed and logistic regression modeling using significant variables was utilized to estimate odds of mortality. There were a total of 7640 patients over the study period. 7% (n=580) of the burn cohort with inhalation injury were included in this study. In-hospital burn mortality for inhalation injury patients was 23%. Current smokers (20%) included cigarette smokers and marijuana users, 19% and 3%, respectively. Preexisting respiratory disease (17%) was present in 36% of smokers compared to 13% of non-smokers (p<0.001). Smokers had significantly lower mortality rate (9%) compared to non-smokers (26%, p<0.01). The logistic regression model for mortality outcomes identified statistically four significant variables: age, TBSA, ethnicity, and smoker status (OR=0.41, 95% CI=0.18-0.93). Presence of comorbidities, including preexisting respiratory disease, was not significant. In the sub group of burn patients with inhalation injury, the odds of mortality significantly decreased in pre-existing smokers after adjusting for significant covariates. We postulate that an immune tolerance mechanism that modulates and diminishes the pro-inflammatory response confers a survival advantage in smokers after exposure to acute smoke inhalation injury. Future prospective studies in human and/or animal models are needed to confirm these findings. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

North African savanna fires and atmospheric carbon dioxide

NASA Technical Reports Server (NTRS)

Iacobellis, Sam F.; Frouin, Robert; Razafimpanilo, Herisoa; Somerville, Richard C. J.; Piper, Stephen C.

1994-01-01

The effect of north African savanna fires on atmospheric CO2 is investigated using a tracer transport model. The model uses winds from operational numerical weather prediction analyses and provides CO2 concentrations as a function of space and time. After a spin-up period of several years, biomass-burning sources are added, and model experiments are run for an additional year, utilizing various estimates of CO2 sources. The various model experiments show that biomass burning in the north African savannas significantly affects CO2 concentrations in South America. The effect is more pronounced during the period from January through March, when biomass burning in South America is almost nonexistent. During this period, atmospheric CO2 concentrations in parts of South America typically may increase by 0.5 to 0.75 ppm at 970 mbar, the average pressure of the lowest model layer. These figures are above the probable uncertainty level, as model runs with biomass-burning sources estimated from independent studies using distinct data sets and techniques indicate. From May through September, when severe biomass burning occurs in South America, the effect of north African savanna fires over South America has become generally small at 970 mbar, but north of the equator it may be of the same magnitude or larger than the effect of South American fires. The CO2 concentration increase in the extreme northern and southern portions of South America, however, is mostly due to southern African fires, whose effect may be 2-3 times larger than the effect of South American fires at 970 mbar. Even in the central part of the continent, where local biomass-burning emissions are maximum, southern African fires contribute to at least 15% of the CO2 concentration increase at 970 mbar. At higher levels in the atmosphere, less CO2 emitted by north African savanna fires reaches South America, and at 100 mbar no significant amount of CO2 is transported across the Atlantic Ocean. The vertical structure of the CO2 concentration increase due to biomass burning differs substantially, depending on whether sources are local or remote. A prominent maximum of CO2 concentration increase in the lower layers characterizes the effect of local sources, whereas a more homogeneous profile of CO2 concentration increase characterizes the effect of remote sources. The results demonstrate the strong remote effects of African biomoass burning which, owing to the general circulation of the atmosphere, are felt as far away as South America.

Fibroblast Growth Factor-Peptide Improves Barrier Function and Proliferation in Human Keratinocytes After Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang Kunzhong; Tian Yeping; Yin Liangjie

2011-09-01

Purpose: Epidermal keratinocytes, which can be severely damaged after ionizing radiation (IR), are rapid turnover cells that function as a barrier, protecting the host from pathogenic invasion and fluid loss. We tested fibroblast growth factor-peptide (FGF-P), a small peptide derived from the receptor-binding domain of FGF-2, as a potential mitigator of radiation effects via proliferation and the barrier function of keratinocytes. Methods and Materials: Keratinocytes isolated from neonatal foreskin were grown on transwells. After being exposed to 0, 5, or 10 Gy IR, the cells were treated with a vehicle or FGF-P. The permeability of IR cells was assessed bymore » using transepithelial electrical resistance (TEER) and a paracellular tracer flux of fluorescein isothiocyanate-conjugated bovine serum albumin (FITC-BSA) with Ussing chambers. The cell proliferation was measured with yellow tetrazolium salt (MTT) and tritiated thymidine ([{sup 3}H]-TdR) assays. The phosphorylation of extracellular signal-regulated kinases (ERK) was measured in an enzyme-linked immunosorbent (ELISA)-like assay, and the proteins related to tight junctions (TJ) and adherens junctions (AJ) were examined with Western blotting. We used a mouse model to assess the ability of FGF-P to promote the healing of skin {beta} burns created with a strontium applicator. Results: We found (1) FGF-P reduced the permeability of irradiated keratinocytes, as evidenced by increased TEER and decreased diffusion of FITC-BSA, both associated with the regulation of different proteins and levels of TJ and AJ; and (2) FGF-P enhanced the proliferation of irradiated keratinocytes, as evidenced by increased MTT activity and [{sup 3}H]-TdR incorporation, which was associated with activation of the ERK pathway; and (3) FGF-P promoted the healing of skin {beta} burns. Conclusions: FGF-P enhances the barrier function, including up-regulation of TJ proteins, increases proliferation of human keratinocytes, and accelerates the healing of skin {beta} burns. FGF-P is a promising mitigator that improves the proliferation and barrier function of keratinocytes after IR.« less

Quantitative long term measurements of burns in a rat model using Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI)

PubMed Central

Ponticorvo, Adrien; Burmeister, David M.; Rowland, Rebecca; Baldado, Melissa; Kennedy, Gordon T.; Saager, Rolf; Bernal, Nicole; Choi, Bernard; Durkin, Anthony J.

2017-01-01

The current standard for diagnosis of burn severity and subsequent wound healing is through clinical examination, which is highly subjective. Several new technologies are shifting focus to burn care in an attempt to help quantify not only burn depth but also the progress of healing. While accurate early assessment of partial thickness burns is critical for dictating the course of treatment, the ability to quantitatively monitor wound status over time is critical for understanding treatment efficacy. SFDI and LSI are both non-invasive imaging modalities that have been shown to have great diagnostic value for burn severity, but have yet to be tested over the course of wound healing. In this study, a hairless rat model (n=6, 300-450g) was used with a four pronged comb to create four identical partial thickness burns (superficial n=3 and deep n=3) that were used to monitor wound healing over a 28 day period. Weekly biopsies were taken for histological analysis to verify wound progression. Both SFDI and LSI were performed weekly to track the evolution of hemodynamic (blood flow and oxygen saturation) and structural (reduced scattering coefficient) properties for the burns. LSI showed significant changes in blood flow from baseline to 220% in superficial and 165% in deep burns by day 7. In superficial burns, blood flow returned to baseline levels by day 28, but not for deep burns where blood flow remained elevated. Smaller increases in blood flow were also observed in the surrounding tissue over the same time period. Oxygen saturation values measured with SFDI showed a progressive increase from baseline values of 66% to 74% in superficial burns and 72% in deep burns by day 28. Additionally, SFDI showed significant decreases in the reduced scattering coefficient shortly after the burns were created. The scattering coefficient progressively decreased in the wound area, but returned towards baseline conditions at the end of the 28 day period. Scattering changes in the surrounding tissue remained constant despite the presence of hemodynamic changes. Here we show that LSI and SFDI are capable of monitoring changes in hemodynamic and scattering properties in burn wounds over a 28 day period. These results highlight the potential insights that can be gained by using noninvasive imaging technologies to study wound healing. Further development of these technologies could be revolutionary for wound monitoring and studying the efficacy of different treatments. PMID:28220508

Assessing the predictive capability of optical imaging techniques, Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Imaging (LSI), to the gold standard of clinical assessment in a controlled animal model

NASA Astrophysics Data System (ADS)

Ponticorvo, A.; Rowland, R.; Baldado, M.; Burmeister, D. M.; Christy, R. J.; Bernal, N.; Durkin, A. J.

2018-02-01

The current standard for assessment of burn severity and subsequent wound healing is through clinical examination, which is highly subjective. Accurate early assessment of burn severity is critical for dictating the course of wound management. Complicating matters is the fact that burn wounds are often large and can have multiple regions that vary in severity. In order to manage the treatment more effectively, a tool that can provide spatially resolved information related to mapping burn severity could aid clinicians when making decisions. Several new technologies focus on burn care in an attempt to help clinicians objectively determine burn severity. By quantifying perfusion, laser speckle imaging (LSI) has had success in categorizing burn wound severity at earlier time points than clinical assessment alone. Additionally, spatial frequency domain imaging (SFDI) is a new technique that can quantify the tissue structural damage associated with burns to achieve earlier categorization of burn severity. Here we compared the performance of a commercial LSI device (PeriCam PSI, Perimed Inc.), a SFDI device (Reflect RSTM, Modulated Imaging Inc.) and conventional clinical assessment in a controlled (porcine) model of graded burn wound severity over the course of 28 days. Specifically we focused on the ability of each system to predict the spatial heterogeneity of the healed wound at 28 days, based on the images at an early time point. Spatial heterogeneity was defined by clinical assessment of distinct regions of healing on day 28. Across six pigs, 96 burn wounds (3 cm diameter) were created. Clinical assessment at day 28 indicated that 39 had appeared to heal in a heterogeneous manner. Clinical observation at day 1 found 35 / 39 (90%) to be spatially heterogeneous in terms of burn severity. The LSI system was able to detect spatial heterogeneity of burn severity in 14 / 39 (36%) cases on day 1 and 23 / 39 cases (59%) on day 7. By contrast the SFDI system was able to detect spatial heterogeneity of burn severity in 39 / 39 (100%) cases on day 1. Here we have demonstrated that for the purposes of predicting heterogeneity in wound healing, SFDI generated scattering properties were a significantly more effective tool than perfusion images measured using LSI. This indicates that SFDI may be better suited to help clinicians categorize different burns earlier, ultimately informing treatment strategy to improve patient outcomes.

Numerical study of external burning flowfields

NASA Technical Reports Server (NTRS)

Bittner, Robert D.; Mcclinton, Charles R.

1991-01-01

This paper demonstrates the successful application of CFD to modeling an external burning flowfield. The study used the 2D, 3D, and PNS versions of the SPARK code. Various grids, boundary conditions, and ignition methodologies have been employed. Flameholding was achieved through the use of a subsonic outflow condition and a hot block located behind the step to ignite the fuel. Since the resulting burning produces a large subsonic region downstream of the cowl, this entire surface can be pressurized to the level of the back pressure. An evaluation of interactions between the ramjet exhaust and the external burning products demonstrate the complexity of this design issue. Ths code is now capable of evaluating the external burning effectiveness for flight vehicles using simple injector schemes, and the methodology can be readily applied to other external burning designs.

Biomass Burning and Natural Emissions in the Amazon Rainforest: Impact on the Oxidative Capacity of the Atmosphere

NASA Astrophysics Data System (ADS)

dos Santos, F. C.; Guenther, A. B.; Longo, K.; Freitas, S. R.; Moreira, D. S.; Flávio, L.; Braz, R.; Brito, J.; Oram, D.; Forster, G.; Lee, J. D.; Bauguitte, S.

2015-12-01

Terrestrial vegetation, especially tropical forests, releases large amounts of biogenic volatile organic compounds (BVOC) into the atmosphere. The global emissions of BVOC (~1000 Tg C/year) are dominant in relation to anthropogenic volatile organic compounds (~100 Tg C/year), with biomass burning contributing close to 10 - 50 Tg C/year. Tropical trees cover about 18% of the global land surface but are estimated to be responsible for approximately 80% of terpenoid and 50% of other BVOCs emissions. Considering the importance of these emissions, the SAMBBA (South American Biomass Burning Analysis) experiment, which occurred during the dry season (September 2012) in the Amazon Rainforest, provided information about the chemical composition of the atmosphere through measurements on the aircraft FAAM BAE-146. Although primarily focused on biomass burning flights, the SAMBBA project carried out other flights providing indirect oxidative capacity data in different environments: natural emission dominated flights and biomass burning flights with fresh plumes (< 2 hours) and aged plumes (> 2 hours). Calculation of the [MVK+MACR]/[Isoprene] ratio enabled investigation of the impact of biomass burning on surface oxidation in comparison to the natural emission flights. During the morning (altitude < 500m), the [MVK+MACR]/[Isoprene] values for natural emission flights (1.0±0.4), fresh plume (1.9±0.6) and aged plume (1.4±0.6) suggest that biomass burning enhances BVOC oxidation in relation to the lifetime of the air mass. This study aims to improve the knowledge about the oxidative capacity of the atmosphere, which depends not only on chemical composition, but also other factors like the history of the air mass trajectories influencing the availability of these compounds, the NOx dependence of isoprene oxidation and whether the chemistry is dominated by OH or O3. A synergistic approach integrating observation and modeling, using 3D numerical model of chemical transport (CCATT-BRAMS) coupled with a natural emission model (MEGAN) has been applied to study the BVOC in the Amazon rainforest. The SAMBBA experiment provided a valuable database that is being included into a numerical model of air quality, developing a numerical model that incorporates the understanding needed to represent the observations.

Rational Design of Mouse Models for Cancer Research.

PubMed

Landgraf, Marietta; McGovern, Jacqui A; Friedl, Peter; Hutmacher, Dietmar W

2018-03-01

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models. Copyright © 2017 Elsevier Ltd. All rights reserved.

Atmospheric response and feedback to radiative forcing from biomass burning in tropical South America

Treesearch

Yongqiang Liu

2005-01-01

Simulations are performed to understand the importance of smoke from biomass burning in tropical South America to regional radiation and climate. The National Center for Atmospheric Research (NCAR) regional climate model coupled with the NCAR column radiative model is used to estimate smoke direct radiative forcing and consequent atmospheric perturbations during a...

Emissions from prescribed burning of agricultural fields in the Pacific Northwest

Treesearch

A. L. Holder; B. K. Gullett; S. P. Urbanski; R. Elleman; S. O' Neill; D. Tabor; W. Mitchell; K. R. Baker

2017-01-01

Prescribed burns of winter wheat stubble and Kentucky bluegrass fields in northern Idaho and eastern Washington states (U.S.A.) were sampled using ground-, aerostat-, airplane-, and laboratory-based measurement platforms to determine emission factors, compare methods, and provide a current and comprehensive set of emissions data for air quality models, climate models,...

The impact of a 2 X CO2 climate on lightning-caused fires

NASA Technical Reports Server (NTRS)

Price, Colin; Rind, David

1994-01-01

Future climate change could have significant repercussions for lightning-caused wildfires. Two empirical fire models are presented relating the frequency of lightning fires and the area burned by these fires to the effective precipitation and the frequency of thunderstorm activity. One model deals with the seasonal variations in lightning fires, while the second model deals with the interannual variations of lightning fires. These fire models are then used with the Goddard Institute for Space Studies General Circulation Model to investigate possible changes in fire frequency and area burned in a 2 X CO2 climate. In the United States, the annual mean number of lightning fires increases by 44%, while the area burned increases by 78%. On a global scale, the largest increase in lightning fires can be expected in untouched tropical ecosystems where few natural fires occur today.

Modelling of pore coarsening in the high burn-up structure of UO2 fuel

NASA Astrophysics Data System (ADS)

Veshchunov, M. S.; Tarasov, V. I.

2017-05-01

The model for coalescence of randomly distributed immobile pores owing to their growth and impingement, applied by the authors earlier to consideration of the porosity evolution in the high burn-up structure (HBS) at the UO2 fuel pellet periphery (rim zone), was further developed and validated. Predictions of the original model, taking into consideration only binary impingements of growing immobile pores, qualitatively correctly describe the decrease of the pore number density with the increase of the fractional porosity, however notably underestimate the coalescence rate at high burn-ups attained in the outmost region of the rim zone. In order to overcome this discrepancy, the next approximation of the model taking into consideration triple impingements of growing pores was developed. The advanced model provides a reasonable consent with experimental data, thus demonstrating the validity of the proposed pore coarsening mechanism in the HBS.

A novel role of topical iodine in skin: Activation of the Nrf2 pathway.

PubMed

Ben-Yehuda Greenwald, Maya; Frušić-Zlotkin, Marina; Soroka, Yoram; Ben-Sasson, Shmuel; Bianco-Peled, Havazelet; Kohen, Ron

2017-03-01

For a long time iodine has been used as an active dermal agent in the treatment of inflammatory, immune-mediated and infectious diseases. Moreover, topical iodine application has been reported to provide protection against sulfur-mustard-induced skin lesions, heat-induced and acid-induced skin burns in both haired guinea-pigs and mouse ear swelling models. However, the exact mechanism of action underlying these benefits of iodine has not yet been elucidated. In the current study, a novel mechanism of action by which iodine provides skin protection and relief, based on its electrophilic nature, is suggested. This study demonstrates that both iodine and iodide are capable of activating the Nrf2 pathway in human skin. As a result, skin protection against UVB-induced damage was acquired and the secretion of pro-inflammatory cytokines (IL-6, IL-8) from LPS-challenged skin was reduced. Iodide role in the enhanced activation of this pathway is demonstrated. The mode of action by which iodine and iodide activate the Nrf2 pathway is discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Review of DoD Malaria Research Programs,

DTIC Science & Technology

1992-05-01

the irraliated sporozoite vaccine. Work in the mouse model system and then extrapolate to human malarias. Study naturally acquired immune ...recombinant vaccines. Work simultaneously in the mouse model system and with human malarias. 3. Identify targets and mechanisms of protective immunity not...multivalent vaccines that attack these same targets. 3. Working again in the mouse model, non- human primate model, andI human systems we

A characterization methodology for post-wildfire flood hazard assessments

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLin, Stephen G.; Van Eeckhout, M. E.; Springer, E. P.

A combined GIS-HEC modeling application for floodplain analysis of pre- and post-burned watersheds is described. The burned study area is located on Pajarito Plateau near Los Alamos, New Mexico (USA), where the Cerro Grande Wildfire burned 17,353 ha (42,878 ac) in May 2000. This area is dominated by rugged mountains that are dissected by numerous steep canyons having both ephemeral and perennial channel reaches. Vegetation consists of pinon-juniper woodlands located between 1,829-2,134 m (6,000-7,000 ft) above mean sea level (m MSL), and Ponderosa pine stands between 2,134-3,048 m MSL (7,000-10,000 ft). Approximately seventeen percent of the burned area is locatedmore » within Los Alamos National Laboratory, and the remainder is located in upstream or adjacent watersheds. Pre-burn floodplains were previously mapped in 1991-92 using early HEC models as part of the RCRA/HSWA permitting process. Numerous recording precipitation and stream gages have also been installed. These data provide essential information characterizing rainfall-runoff relationships before and after the fire. They are also being used to monitor spatial and temporal changes as forest recovery progresses. Post-burn changes in HEC-HMS predicted rainfall-runoff patterns are related to changes in watershed vegetation cover and hydrophobic soil conditions. Stream channel cross-sectional geometries were extracted from 0.3 m (1 ft) DEM data using ArcView GIS. Then floodpool topwidths, depths, and flow velocities were remapped using the HEC-RAS model. Finally, numerous surveyed channel sections were selectively made at crucial sites for model verification. Direct comparisons are made between alternative data acquisition and mapping techniques.« less

Birth Outcomes Among Military Personnel Following Exposure to Documented Open-Air Burn Pits Before and During Pregnancy

DTIC Science & Technology

2012-06-01

of the parents’ exposure to the onset of pregnancy ( maternal model) or EDC ( paternal model), cumulative days of exposure to a burn pit region before...the infant’s date of birth ( maternal model) or EDC ( paternal model), and last exposed deployment, defined as the parent’s duty location (ie, Joint Base...in Table 1. Maternal age (ie, age of the deployer in the maternal model and the deployer’s spouse in the paternal model) was lower (ន years) among

Land surface temperature as potential indicator of burn severity in forest Mediterranean ecosystems

NASA Astrophysics Data System (ADS)

Quintano, C.; Fernández-Manso, A.; Calvo, L.; Marcos, E.; Valbuena, L.

2015-04-01

Forest fires are one of the most important causes of environmental alteration in Mediterranean countries. Discrimination of different degrees of burn severity is critical for improving management of fire-affected areas. This paper aims to evaluate the usefulness of land surface temperature (LST) as potential indicator of burn severity. We used a large convention-dominated wildfire, which occurred on 19-21 September, 2012 in Northwestern Spain. From this area, a 1-year series of six LST images were generated from Landsat 7 Enhanced Thematic Mapper (ETM+) data using a single channel algorithm. Further, the Composite Burn Index (CBI) was measured in 111 field plots to identify the burn severity level (low, moderate, and high). Evaluation of the potential relationship between post-fire LST and ground measured CBI was performed by both correlation analysis and regression models. Correlation coefficients were higher in the immediate post-fire LST images, but decreased during the fall of 2012 and increased again with a second maximum value in summer, 2013. A linear regression model between post-fire LST and CBI allowed us to represent spatially predicted CBI (R-squaredadj > 85%). After performing an analysis of variance (ANOVA) between post-fire LST and CBI, a Fisher's least significant difference test determined that two burn severity levels (low-moderate and high) could be statistically distinguished. The identification of such burn severity levels is sufficient and useful to forest managers. We conclude that summer post-fire LST from moderate resolution satellite data may be considered as a valuable indicator of burn severity for large fires in Mediterranean forest ecosytems.

Animal models for prenatal gene therapy: rodent models for prenatal gene therapy.

PubMed

Roybal, Jessica L; Endo, Masayuki; Buckley, Suzanne M K; Herbert, Bronwen R; Waddington, Simon N; Flake, Alan W

2012-01-01

Fetal gene transfer has been studied in various animal models, including rabbits, guinea pigs, cats, dogs, and nonhuman primate; however, the most common model is the rodent, particularly the mouse. There are numerous advantages to mouse models, including a short gestation time of around 20 days, large litter size usually of more than six pups, ease of colony maintenance due to the small physical size, and the relatively low expense of doing so. Moreover, the mouse genome is well defined, there are many transgenic models particularly of human monogenetic disorders, and mouse-specific biological reagents are readily available. One criticism has been that it is difficult to perform procedures on the fetal mouse with suitable accuracy. Over the past decade, accumulation of technical expertise and development of technology such as high-frequency ultrasound have permitted accurate vector delivery to organs and tissues. Here, we describe our experiences of gene transfer to the fetal mouse with and without ultrasound guidance from mid to late gestation. Depending upon the vector type, the route of delivery and the age of the fetus, specific or widespread gene transfer can be achieved, making fetal mice excellent models for exploratory biodistribution studies.

Impaired Respiratory Function and Heightened Pulmonary Inflammation in Episodic Binge Ethanol Intoxication and Burn Injury

PubMed Central

Shults, Jill A.; Curtis, Brenda J.; Chen, Michael M.; O'Halloran, Eileen B.; Ramirez, Luis; Kovacs, Elizabeth J.

2015-01-01

Clinical data indicate that cutaneous burn injuries covering greater than ten percent total body surface area are associated with significant morbidity and mortality, where pulmonary complications, including acute respiratory distress syndrome (ARDS), contribute to nearly half of all patient deaths. Approximately 50% of burn patients are intoxicated at the time of hospital admission, which increases days on ventilators by three-fold, and doubles length of hospital admittance, compared to non-intoxicated burn patients. The most common drinking pattern in the United States is binge drinking, where one rapidly consumes alcoholic beverages (4 for women, 5 for men) in 2 hours and an estimated 38 million Americans binge drink, often several times per month. Experimental data demonstrate a single binge ethanol exposure prior to scald injury, impairs innate and adaptive immune responses, thereby enhancing infection susceptibility and amplifying pulmonary inflammation, neutrophil infiltration, and edema, and is associated with increased mortality. Since these characteristics are similar to those observed in ARDS burn patients, our study objective was to determine whether ethanol intoxication and burn injury and the subsequent pulmonary congestion affects physiological parameters of lung function using non-invasive and unrestrained plethysmography in a murine model system. Furthermore, to mirror young adult binge drinking patterns, and to determine the effect of multiple ethanol exposures on pulmonary inflammation, we utilized an episodic binge ethanol exposure regimen, where mice were exposed to ethanol for a total of 6 days (3 days ethanol, 4 days rest, 3 days ethanol) prior to burn injury. Our analyses demonstrate mice exposed to episodic binge ethanol and burn injury have higher mortality, increased pulmonary congestion and neutrophil infiltration, elevated neutrophil chemoattractants, and respiratory dysfunction, compared to burn or ethanol intoxication alone. Overall, our study identifies plethysmography as a useful tool for characterizing respiratory function in a murine burn model and for future identification of therapeutic compounds capable of restoring pulmonary functionality. PMID:26364264

Brown adipose tissue and its modulation by a mitochondria-targeted peptide in rat burn injury-induced hypermetabolism

PubMed Central

Yo, Kikuo; Yu, Yong-Ming; Zhao, Gaofeng; Bonab, Ali A.; Aikawa, Naoki; Tompkins, Ronald G.

2013-01-01

Hypermetabolism is a prominent feature of burn injury, and altered mitochondria function is presumed to contribute to this state. Recently, brown adipose tissue (BAT) was found to be present not only in rodents but also in humans, and its activity is associated with resting metabolic rate. In this report, we elucidate the relationship between burn injury-induced hypermetabolism and BAT activity and the possible role of the mitochondria-targeted peptide SS31 in attenuating burn injury-induced hypermetabolism by using a rat burn injury model. We demonstrate that burn injury induces morphological changes in interscapular BAT (iBAT). Burn injury was associated with iBAT activation, and this effect was positively correlated with increased energy expenditure. BAT activation was associated with augmentation of mitochondria biogenesis, and UCP1 expression in the isolated iBAT mitochondria. In addition, the mitochondria-targeted peptide SS31 attenuated burn injury-induced hypermetabolism, which was accompanied by suppression of UCP1 expression in isolated mitochondria. Our results suggest that BAT plays an important role in burn injury-induced hypermetabolism through its morphological changes and expression of UCP1. PMID:23169784

Brown adipose tissue and its modulation by a mitochondria-targeted peptide in rat burn injury-induced hypermetabolism.

PubMed

Yo, Kikuo; Yu, Yong-Ming; Zhao, Gaofeng; Bonab, Ali A; Aikawa, Naoki; Tompkins, Ronald G; Fischman, Alan J

2013-02-15

Hypermetabolism is a prominent feature of burn injury, and altered mitochondria function is presumed to contribute to this state. Recently, brown adipose tissue (BAT) was found to be present not only in rodents but also in humans, and its activity is associated with resting metabolic rate. In this report, we elucidate the relationship between burn injury-induced hypermetabolism and BAT activity and the possible role of the mitochondria-targeted peptide SS31 in attenuating burn injury-induced hypermetabolism by using a rat burn injury model. We demonstrate that burn injury induces morphological changes in interscapular BAT (iBAT). Burn injury was associated with iBAT activation, and this effect was positively correlated with increased energy expenditure. BAT activation was associated with augmentation of mitochondria biogenesis, and UCP1 expression in the isolated iBAT mitochondria. In addition, the mitochondria-targeted peptide SS31 attenuated burn injury-induced hypermetabolism, which was accompanied by suppression of UCP1 expression in isolated mitochondria. Our results suggest that BAT plays an important role in burn injury-induced hypermetabolism through its morphological changes and expression of UCP1.

Mercury emissions from biomass burning in China.

PubMed

Huang, Xin; Li, Mengmeng; Friedli, Hans R; Song, Yu; Chang, Di; Zhu, Lei

2011-11-01

Biomass burning covers open fires (forest and grassland fires, crop residue burning in fields, etc.) and biofuel combustion (crop residues and wood, etc., used as fuel). As a large agricultural country, China may produce large quantities of mercury emissions from biomass burning. A new mercury emission inventory in China is needed because previous studies reflected outdated biomass burning with coarse resolution. Moreover, these studies often adopted the emission factors (mass of emitted species per mass of biomass burned) measured in North America. In this study, the mercury emissions from biomass burning in China (excluding small islands in the South China Sea) were estimated, using recently measured mercury concentrations in various biomes in China as emission factors. Emissions from crop residues and fuelwood were estimated based on annual reports distributed by provincial government. Emissions from forest and grassland fires were calculated by combining moderate resolution imaging spectroradiometer (MODIS) burned area product with combustion efficiency (ratio of fuel consumption to total available fuels) considering fuel moisture. The average annual emission from biomass burning was 27 (range from 15.1 to 39.9) Mg/year. This inventory has high spatial resolution (1 km) and covers a long period (2000-2007), making it useful for air quality modeling.

Air Pollution Episodes Associated with Prescribed Burns

NASA Astrophysics Data System (ADS)

Hart, M.; Di Virgilio, G.; Jiang, N.

2017-12-01

Air pollution events associated with wildfires have been associated with extreme health impacts. Prescribed burns are an important tool to reduce the severity of wildfires. However, if undertaken during unfavourable meteorological conditions, they too have the capacity to trigger extreme air pollution events. The Australian state of New South Wales has increased the annual average area treated by prescribed burn activities by 45%, in order to limit wildfire activity. Prescribed burns need to be undertaken during meteorological conditions that allow the fuel load to burn, while still allowing the burn to remain under control. These conditions are similar to those that inhibit atmospheric dispersion, resulting in a fine balance between managing fire risk and managing ambient air pollution. During prescribed burns, the Sydney air shed can experience elevated particulate matter concentrations, especially fine particulates (PM2.5) that occasionally exceed national air quality standards. Using pollutant and meteorological data from sixteen monitoring stations in Sydney we used generalized additive model and CART analyses to profile the meteorological conditions influencing air quality during planned burns. The insights gained from this study will help improve prescribed burn scheduling in order to reduce the pollution risk to the community, while allowing fire agencies to conduct this important work.

A novel perspective for burn-induced myopathy: Membrane repair defect

PubMed Central

Wang, Chao; Wang, Hongyu; Wu, Dan; Hu, Jianhong; Wu, Wei; Zhang, Yong; Peng, Xi

2016-01-01

Myopathy is a common complication of severe burn patients. One potential cause of this myopathy could be failure of the plasma membrane to undergo repair following injuries generated from toxin or exercise. The aim of this study is to assess systemic effect on muscle membrane repair deficiency in burn injury. Skeletal muscle fibers isolated from burn-injured mice were damaged with a UV laser and dye influx imaged confocally to evaluate membrane repair capacity. Membrane repair failure was also tested in burn-injured mice subjected to myotoxin or treadmill exercise. We further used C2C12 myotubules and animal models to investigate the role of MG53 in development of burn-induced membrane repair defect. We demonstrated that skeletal muscle myofibers in burn-injured mice showed significantly more dye uptake after laser damage than controls, indicating a membrane repair deficiency. Myotoxin or treadmill exercise also resulted in a higher-grade repair defect in burn-injured mice. Furthermore, we observed that burn injury induced a significant decrease in MG53 levels and its dimerization in skeletal muscles. Our findings highlight a new mechanism that implicates membrane repair failure as an underlying cause of burn-induced myopathy. And, the disorders in MG53 expression and MG53 dimerization are involved in this cellular pathology. PMID:27545095

The management of small area burns and unexpected illness after burn in children under five years of age - A costing study in the English healthcare setting.

PubMed

Kandiyali, R; Sarginson, J H; Hollén, L I; Spickett-Jones, F; Young, A E R

2018-02-01

The objective of this economic study was to evaluate the resource use and cost associated with the management of small area burns, including the additional costs associated with unexpected illness after burn in children of less than five years of age. This study was conducted as a secondary analysis of a multi-centre prospective observational cohort study investigating the physiological response to burns in children. 452 children were included in the economic analysis (median age=1.60years, 61.3% boys, median total burn surface area [TBSA]=1.00%) with a mean length of stay of 0.69 days. Of these children, 21.5% re-presented to medical care with an unexpected illness within fourteen days of injury. The cost of managing a burn of less than 10% TBSA in a child less than five years of age was £785. The additional cost associated with the management of illness after burn was £1381. A generalised linear regression model was used to determine the association between an unexpected illness after burn, presenting child characteristics and NHS cost. Our findings may be of value to those planning economic evaluations of novel technologies in burn care. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Use of multi-sensor active fire detections to map fires in the United States: the future of monitoring trends in burn severity

USGS Publications Warehouse

Picotte, Joshua J.; Coan, Michael; Howard, Stephen M.

2014-01-01

The effort to utilize satellite-based MODIS, AVHRR, and GOES fire detections from the Hazard Monitoring System (HMS) to identify undocumented fires in Florida and improve the Monitoring Trends in Burn Severity (MTBS) mapping process has yielded promising results. This method was augmented using regression tree models to identify burned/not-burned pixels (BnB) in every Landsat scene (1984–2012) in Worldwide Referencing System 2 Path/Rows 16/40, 17/39, and 1839. The burned area delineations were combined with the HMS detections to create burned area polygons attributed with their date of fire detection. Within our study area, we processed 88,000 HMS points (2003–2012) and 1,800 Landsat scenes to identify approximately 300,000 burned area polygons. Six percent of these burned area polygons were larger than the 500-acre MTBS minimum size threshold. From this study, we conclude that the process can significantly improve understanding of fire occurrence and improve the efficiency and timeliness of assessing its impacts upon the landscape.

Patterns of burns and scalds in Mongolian children: a hospital-based prospective study.

PubMed

Gerelmaa, Gunsmaa; Tumen-Ulzii, Badarch; Nakahara, Shinji; Ichikawa, Masao

2018-03-01

To describe the circumstances of burn injury occurrence among Mongolian children and the products involved. Study participants were children aged 15 years and younger who were admitted to the Burn Unit of the National Trauma Orthopedic Research Center from August 2015 to July 2016. We collected data on participant demographics and the aetiology and clinical features of their burn injuries, and we analysed the data based on the NOMESCO Classification model. Of 906 children, 83% were aged 0-3 years, 66% were injured around the cooking area in the traditional tent-like dwelling called a ger or a detached house where no specified kitchen exists, and 28% were injured in a kitchen. Burn injuries resulted mostly from exposure to overflowing hot liquids (93%). Electric pots and electric kettles were the products most frequently involved in causing burn injuries (41% and 14%, respectively). Of 601 major burn injuries, 52% were due to electric pots. Moreover, burn injuries inflicted by electric pots were most likely to be major burn injuries (83%). Children typically fell into electric pots, while electric kettles were often pulled down by children. Burn injuries among Mongolian children mainly occurred in cooking area of a ger involving electric pots. The current practice of cooking on the floor should be reconsidered for child burn prevention. © 2018 John Wiley & Sons Ltd.

Microstructural modeling of thermal conductivity of high burn-up mixed oxide fuel

NASA Astrophysics Data System (ADS)

Teague, Melissa; Tonks, Michael; Novascone, Stephen; Hayes, Steven

2014-01-01

Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISON [1] fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez-Lucuta model was favorable.

Microstructural Modeling of Thermal Conductivity of High Burn-up Mixed Oxide Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melissa Teague; Michael Tonks; Stephen Novascone

2014-01-01

Predicting the thermal conductivity of oxide fuels as a function of burn-up and temperature is fundamental to the efficient and safe operation of nuclear reactors. However, modeling the thermal conductivity of fuel is greatly complicated by the radially inhomogeneous nature of irradiated fuel in both composition and microstructure. In this work, radially and temperature-dependent models for effective thermal conductivity were developed utilizing optical micrographs of high burn-up mixed oxide fuel. The micrographs were employed to create finite element meshes with the OOF2 software. The meshes were then used to calculate the effective thermal conductivity of the microstructures using the BISONmore » fuel performance code. The new thermal conductivity models were used to calculate thermal profiles at end of life for the fuel pellets. These results were compared to thermal conductivity models from the literature, and comparison between the new finite element-based thermal conductivity model and the Duriez–Lucuta model was favorable.« less

Numerical computation of Pop plot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menikoff, Ralph

The Pop plot — distance-of-run to detonation versus initial shock pressure — is a key characterization of shock initiation in a heterogeneous explosive. Reactive burn models for high explosives (HE) must reproduce the experimental Pop plot to have any chance of accurately predicting shock initiation phenomena. This report describes a methodology for automating the computation of a Pop plot for a specific explosive with a given HE model. Illustrative examples of the computation are shown for PBX 9502 with three burn models (SURF, WSD and Forest Fire) utilizing the xRage code, which is the Eulerian ASC hydrocode at LANL. Comparisonmore » of the numerical and experimental Pop plot can be the basis for a validation test or as an aid in calibrating the burn rate of an HE model. Issues with calibration are discussed.« less

A porcine deep dermal partial thickness burn model with hypertrophic scarring.

PubMed

Cuttle, Leila; Kempf, Margit; Phillips, Gael E; Mill, Julie; Hayes, Mark T; Fraser, John F; Wang, Xue-Qing; Kimble, Roy M

2006-11-01

We developed a reproducible model of deep dermal partial thickness burn injury in juvenile Large White pigs. The contact burn is created using water at 92 degrees C for 15s in a bottle with the bottom replaced with plastic wrap. The depth of injury was determined by a histopathologist who examined tissue sections 2 and 6 days after injury in a blinded manner. Upon creation, the circular wound area developed white eschar and a hyperaemic zone around the wound border. Animals were kept for 6 weeks or 99 days to examine the wound healing process. The wounds took between 3 and 5 weeks for complete re-epithelialisation. Most wounds developed contracted, purple, hypertrophic scars. On measurement, the thickness of the burned skin was approximately 1.8 times that of the control skin at week 6 and approximately 2.2 times thicker than control skin at 99 days after injury. We have developed various methods to assess healing wounds, including digital photographic analysis, depth of organising granulation tissue, immunohistochemistry, electron microscopy and tensiometry. Immunohistochemistry and electron microscopy showed that our porcine hypertrophic scar appears similar to human hypertrophic scarring. The development of this model allows us to test and compare different treatments on burn wounds.

Treatment of d-galactose induced mouse aging with Lycium barbarum polysaccharides and its mechanism study.

PubMed

Tang, Tao; He, Bixiu

2013-01-01

We evaluated the effects of Lycium barbarum polysaccharides LBP) on D-galactose aging model mouse, and explored its possible mechanism. Kunming mice were randomly divided into the control group, the model group, the high-dose LBP group, and the low-dose LBP group. Except the control group, D-galactose was used for modelling. The drug was administrated when modelling. Mouse behavioural, learning and memory changes were observed, and the contents of lipid peroxidation (LPO), lipofuscin (LF) and monoamine oxidase B (MAO-B) in mouse brain tissue and the weight of immune organs were measured after 6 weeks. Compared with the control group, mouse weight gain in the model group reduced significantly. Compared with model group, after mice drank LBP, the times of electric shock was less than aging mice (in which, the high-dose LBP group, P<0.05), and electric shock incubation period was longer (P<0.01). On Day 45 after modelling and drug administration, the contents of LPO, LF and MAO-B in mouse brain tissue in the model group increased significantly, while those in the drug administration groups decreased significantly. The thymus index in the aging model group decreased significantly; the thymus index and the spleen index in the high-dose LBP group and the low-dose LBP group rebounded significantly (P<0.01). We concluded that LBP has an anti-aging effect on D-galactose induced aging model mouse, and its mechanism may be related with the alleviation of glucose metabolism disorder and the resistance of the generation of lipid peroxide and other substances, which damage cell membrane lipid.

Does nurses'perceived burn prevention knowledge and ability to teach burn prevention correlate with their actual burn prevention knowledge?

PubMed

Lehna, Carlee; Myers, John

2010-01-01

The purpose of this study was to explore the relationship among nurses'perceived burn prevention knowledge, their perceived ability to teach about burn prevention, and their actual burn prevention knowledge and to test if their actual burn knowledge could be predicted by these perceived measures. A two-page, anonymous survey that included a 10-item burn prevention knowledge test and an assessment of nurses'perceived knowledge of burn prevention and their perceived ability to teach burn prevention was administered to 313 nurses. Actual burn prevention knowledge was determined and the correlation among actual burn prevention knowledge, perceived knowledge, and perceived ability to teach was determined. Differences in these outcome variables based on specialty area were tested using analysis of variance techniques. Generalized linear modeling techniques were used to investigate which variables significantly predict a nurse's actual burn prevention knowledge. Test for interaction effects were performed, and significance was set at .05. Responding nurses (N = 265) described practicing in a variety of settings, such as pediatric settings (40.2%, n = 105), emergency departments (25.4%, n = 86), medical/surgical settings (8.4%, n = 22), and one pediatric burn setting (4.1%, n = 14), with all specialty areas as having similar actual burn prevention knowledge (P = .052). Seventy-seven percent of the nurses said they never taught about burn prevention (n = 177). Perceived knowledge and actual knowledge (r = .124, P = .046) as well as perceived knowledge and perceived ability were correlated (r = .799, P < .001). Significant predictors of actual knowledge were years in practice (beta = -0.063, P = .034), years in current area (beta = 0.072, P = .003), perceived knowledge (beta = 0.109, P = .042), and perceived ability (beta = 0.137, P = .019). All nurses, regardless of specialty area, have poor burn prevention knowledge, which is correlated with their perceived lack of knowledge of burn prevention. In addition, nurses'perceived burn knowledge and ability predicts their actual burn knowledge. This is a fruitful area that merits further research and exploration.

Postwildfire preliminary debris flow hazard assessment for the area burned by the 2011 Las Conchas Fire in north-central New Mexico

USGS Publications Warehouse

Tillery, Anne C.; Darr, Michael J.; Cannon, Susan H.; Michael, John A.

2011-01-01

The Las Conchas Fire during the summer of 2011 was the largest in recorded history for the state of New Mexico, burning 634 square kilometers in the Jemez Mountains of north-central New Mexico. The burned landscape is now at risk of damage from postwildfire erosion, such as that caused by debris flows and flash floods. This report presents a preliminary hazard assessment of the debris-flow potential from 321 basins burned by the Las Conchas Fire. A pair of empirical hazard-assessment models developed using data from recently burned basins throughout the intermountain western United States was used to estimate the probability of debris-flow occurrence and volume of debris flows at the outlets of selected drainage basins within the burned area. The models incorporate measures of burn severity, topography, soils, and storm rainfall to estimate the probability and volume of debris flows following the fire. In response to a design storm of 28.0 millimeters of rain in 30 minutes (10-year recurrence interval), the probabilities of debris flows estimated for basins burned by the Las Conchas Fire were greater than 80 percent for two-thirds (67 percent) of the modeled basins. Basins with a high (greater than 80 percent) probability of debris-flow occurrence were concentrated in tributaries to Santa Clara and Rio del Oso Canyons in the northeastern part of the burned area; some steep areas in the Valles Caldera National Preserve, Los Alamos, and Guaje Canyons in the east-central part of the burned area; tributaries to Peralta, Colle, Bland, and Cochiti canyons in the southwestern part of the burned area; and tributaries to Frijoles, Alamo, and Capulin Canyons in the southeastern part of the burned area (within Bandelier National Monument). Estimated debris-flow volumes ranged from 400 cubic meters to greater than 72,000 cubic meters. The largest volumes (greater than 40,000 cubic meters) were estimated for basins in Santa Clara, Los Alamos, and Water Canyons, and for two basins at the northeast edge of the burned area tributary to Rio del Oso and Vallecitos Creek. The Combined Relative Debris-Flow Hazard Rankings identify the areas of highest probability of the largest debris flows. Basins with high Combined Relative Debris-Flow Hazard Rankings include upper Santa Clara Canyon in the northern section of the burn scar, and portions of Peralta, Colle, Bland, Cochiti, Capulin, Alamo, and Frijoles Canyons in the southern section of the burn scar. Three basins with high Combined Relative Debris-Flow Hazard Rankings also occur in areas upstream from the city of Los Alamos—the city is home to and surrounded by numerous technical sites for the Los Alamos National Laboratory. Potential debris flows in the burned area could affect the water supply for Santa Clara Pueblo and several recreational lakes, as well as recreational and archeological resources in Bandelier National Monument. Debris flows could damage bridges and culverts along State Highway 501 and other roadways. Additional assessment is necessary to determine if the estimated volume of material is sufficient to travel into areas downstream from the modeled basins along the valley floors, where they could affect human life, property, agriculture, and infrastructure in those areas. Additionally, further investigation is needed to assess the potential for debris flows to affect structures at or downstream from basin outlets and to increase the threat of flooding downstream by damaging or blocking flood mitigation structures. The maps presented here may be used to prioritize areas where erosion mitigation or other protective measures may be necessary within a 2- to 3-year window of vulnerability following the Las Conchas Fire.

Accelerant-related burns and drug abuse: Challenging combination.

PubMed

Leung, Leslie T F; Papp, Anthony

2018-05-01

Accelerants are flammable substances that may cause explosion when added to existing fires. The relationships between drug abuse and accelerant-related burns are not well elucidated in the literature. Of these burns, a portion is related to drug manufacturing, which have been shown to be associated with increased burn complications. 1) To evaluate the demographics and clinical outcomes of accelerant-related burns in a Provincial Burn Centre. 2) To compare the clinical outcomes with a control group of non-accelerant related burns. 3) To analyze a subgroup of patients with history of drug abuse and drug manufacturing. Retrospective case control study. Patient data associated with accelerant-related burns from 2009 to 2014 were obtained from the British Columbia Burn Registry. These patients were compared with a control group of non-accelerant related burns. Clinical outcomes that were evaluated include inhalational injury, ICU length of stay, ventilator support, surgeries needed, and burn complications. Chi-square test was used to evaluate categorical data and Student's t-test was used to evaluate mean quantitative data with the p value set at 0.05. A logistic regression model was used to evaluate factors affecting burn complications. Accelerant-related burns represented 28.2% of all burn admissions (N=532) from 2009 to 2014. The accelerant group had higher percentage of patients with history of drug abuse and was associated with higher TBSA burns, ventilator support, ICU stay and pneumonia rates compared to the non-accelerant group. Within the accelerant group, there was no difference in clinical outcomes amongst people with or without history of drug abuse. Four cases were associated with methamphetamine manufacturing, all of which underwent ICU stay and ventilator support. Accelerant-related burns cause significant burden to the burn center. A significant proportion of these patients have history of drug abuse. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

Burn wound healing properties of asiaticoside and madecassoside

PubMed Central

Hou, Qiang; Li, Ming; Lu, Yan-Hua; Liu, Dong-Hong; Li, Cheng-Cun

2016-01-01

The healing of burn wounds has been widely characterized to be highly intricate, involving processes such as neo-vascularization, granulation, re-epithelialization, inflammation and wound contraction. Various therapies are available for the management of burn wounds; however, a truly effective therapeutic strategy has yet to be identified due to safety issues. The aim of the present study was to assess and confirm the burn wound healing properties of the compounds asiaticoside (AE) and madecassoside (MA), which are found in the herb Centella asiatica. The cytotoxic nature of the AE and MA were inspected and were confirmed to be non-toxic up to 500 ppm. The compounds AE and MA increased monocyte chemoattractant protein-1 production, but caused no significant effect on vascular endothelial growth factor production. In addition, an in vivo animal burn model was employed to represent the features of burn wound healing. Hence, the present results warrant the further investigation of C. asiatica extracts for use in burn healing. PMID:27588048

Burn Injury Alters Epidermal Cholinergic Mediators and Increases HMGB1 and Caspase 3 in Autologous Donor Skin and Burn Margin

PubMed Central

Holmes, Casey J.; Plichta, Jennifer K.; Gamelli, Richard L.; Radek, Katherine A.

2016-01-01

Burn wound healing complications, such as graft failure or infection, are a major source of morbidity and mortality in burn patients. The mechanisms by which local burn injury alters epidermal barrier function in autologous donor skin and surrounding burn margin are largely undefined. We hypothesized that defects in the epidermal cholinergic system may impair epidermal barrier function and innate immune responses. The objective was to identify alterations in the epidermal cholinergic pathway, and their downstream targets, associated with inflammation and cell death. We established that protein levels, but not gene expression, of the α7 nicotinic acetylcholine receptor (CHRNA7) were significantly reduced in both donor and burn margin skin. Furthermore, the gene and protein levels of an endogenous allosteric modulator of CHRNA7, secreted mammalian Ly-6/urokinase-type plasminogen activator receptor-related protein-1 (SLURP1) and acetylcholine were significantly elevated in donor and burn margin skin. As downstream proteins of inflammatory and cell death targets of nAChR activation, we found significant elevations in epidermal High Mobility Group Box Protein 1 (HMGB1) and caspase 3 in donor and burn margin skin. Lastly, we employed a novel in vitro keratinocyte burn model to establish that burn injury influences the gene expression of these cholinergic mediators and their downstream targets. These results indicate that defects in cholinergic mediators and inflammatory/apoptotic molecules in donor and burn margin skin may directly contribute to graft failure or infection in burn patients. PMID:27648692

Modeling of the jack rabbit series of experiments with a temperature based reactive burn model

NASA Astrophysics Data System (ADS)

Desbiens, Nicolas

2017-01-01

The Jack Rabbit experiments, performed by Lawrence Livermore National Laboratory, focus on detonation wave corner turning and shock desensitization. Indeed, while important for safety or charge design, the behaviour of explosives in these regimes is poorly understood. In this paper, our temperature based reactive burn model is calibrated for LX-17 and compared to the Jack Rabbit data. It is shown that our model can reproduce the corner turning and shock desensitization behaviour of four out of the five experiments.

Biomass burning aerosol over Romania using dispersion model and Calipso data

NASA Astrophysics Data System (ADS)

Nicolae, Victor; Dandocsi, Alexandru; Marmureanu, Luminita; Talianu, Camelia

2018-04-01

The purpose of the study is to analyze the seasonal variability, for the hot and cold seasons, of biomass burning aerosol observed over Romania using forward dispersion calculations based on FLEXPART model. The model was set up to use as input the MODIS fire data with a degree of confidence over 25% after transforming the emitted power in emission rate. The modelled aerosols in this setup was black carbon coated by organics. Distribution in the upper layers were compared to Calipso retrieval.

Shock Detector for SURF model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Menikoff, Ralph

2016-01-11

SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

Transboundary Transport of Biomass Burning Emissions in Southeast Asia and Contribution to Local Air Quality During the 2006 Fire Event

NASA Astrophysics Data System (ADS)

Aouizerats, B.; van der Werf, G.; Balasubramanian, R.; Betha, R.

2014-12-01

Smoke from biomass and peat burning has a notable impact on ambient air quality and climate in the Southeast Asia (SEA) region. We modeled the largest fire-induced haze episode in the past decade (2006) that originated in Indonesia using WRF-Chem. Our study addressed 3 research questions: (1) Can the WRF-Chem model reproduce observations of both aerosol and CO concentrations in this complex region? (2) What is the evolution in the chemical composition of the aerosol fire plume during its atmospheric transport? and (3) What is the relative contribution of these fires to air quality in the urbanized area of the city-state of Singapore? To test model performance, we used three independent datasets for comparison (PM10 in Singapore, CO measurements in Sumatra, and AOD column observations from 4 satellite-based sensors). We found reasonable agreement of the model runs with ground-based measurements of both CO and PM10. However, the comparison with AOD was less favorable and indicated the model underestimated AOD. In the past, modeling studies using only AOD as a constraint have often boosted fire emissions to get a better agreement with observations. In our case, this approach would seriously deteriorate the difference with ground-based observations. Finally, our results show that about 21% of the total mass loading of ambient PM10 during the July-October study period in Singapore was due to the influence of biomass and peat burning in Sumatra, with an increased contribution during high burning periods. The composition of this biomass burning plume was largely dominated by primary organic carbon. In total, our model results indicated that during 35 days aerosol concentrations in Singapore were above the threshold of 50 μg m-3 day-1 (WHO threshold). During 17 days this deterioration was due to Indonesian fires, based on the difference between the simulations with and without fires. Local air pollution in combination with recirculation of air masses was probably the main cause of the lack of good air quality during the other 18 days. This finding is mostly due to the relatively fine scale of our model set-up; coarser resolution models would have likely attributed the increased aerosol loads to burning in Borneo from which plumes were advected close to Singapore, but did not contribute to local pollution according to our model.