The effects of treading by two breeds of dairy cow with different live weights on soil physical properties, poaching damage and herbage production on a poorly drained clay-loam soil.

PubMed

Tuohy, P; Fenton, O; Holden, N M; Humphreys, J

2015-11-01

There is little empirical evidence to indicate that dairy cow live weight affects the extent of soil damage at the hoof-soil interface during grazing on poorly drained permanent grassland. In the present study the impact of Holstein-Friesian (HF) dairy cows with a mean (±standard deviation) live weight of 570 (±61) kg were compared with Jersey × Holstein-Friesian (JX) with a mean live weight of 499 (±52) kg each at two stocking densities: mean 2·42 ± (0·062) and 2·66 (±0·079) cows/ha. Soil physical properties (bulk density, macroporosity, gravimetric water content, air-filled porosity, penetration resistance and shear strength), poaching damage (post-grazing soil surface deformation and hoof-print depth), herbage yield and milk production were measured throughout 2011 and 2012. Soil physical properties, post-grazing soil surface deformation and herbage production were not affected by dairy cow breed or by interactions between breed and stocking density. Hoof-print depth was higher in the HF treatments (39 v. 37 mm, s.e. 0·5 mm). Loading pressure imposed at the soil surface was the same for both breeds due to a direct correlation between live weight and hoof size. Poaching damage was greater at higher stocking density. Using the lighter JX cow offered little advantage in terms of lowering the negative impact of treading on soil physical properties or reducing poaching damage and no advantage in terms of herbage or milk production compared with the heavier HF cow.

Escape and evade control policies for ensuring the physical security of nonholonomic, ground-based, unattended mobile sensor nodes

NASA Astrophysics Data System (ADS)

Mascarenas, David; Stull, Christopher; Farrar, Charles

2011-06-01

In order to realize the wide-scale deployment of high-endurance, unattended mobile sensing technologies, it is vital to ensure the self-preservation of the sensing assets. Deployed mobile sensor nodes face a variety of physical security threats including theft, vandalism and physical damage. Unattended mobile sensor nodes must be able to respond to these threats with control policies that facilitate escape and evasion to a low-risk state. In this work the Precision Immobilization Technique (PIT) problem has been considered. The PIT maneuver is a technique that a pursuing, car-like vehicle can use to force a fleeing vehicle to abruptly turn ninety degrees to the direction of travel. The abrupt change in direction generally causes the fleeing driver to lose control and stop. The PIT maneuver was originally developed by law enforcement to end vehicular pursuits in a manner that minimizes damage to the persons and property involved. It is easy to imagine that unattended autonomous convoys could be targets of this type of action by adversarial agents. This effort focused on developing control policies unattended mobile sensor nodes could employ to escape, evade and recover from PIT-maneuver-like attacks. The development of these control policies involved both simulation as well as small-scale experimental testing. The goal of this work is to be a step toward ensuring the physical security of unattended sensor node assets.

Physically-based Assessment of Tropical Cyclone Damage and Economic Losses

NASA Astrophysics Data System (ADS)

Lin, N.

2012-12-01

Estimating damage and economic losses caused by tropical cyclones (TC) is a topic of considerable research interest in many scientific fields, including meteorology, structural and coastal engineering, and actuarial sciences. One approach is based on the empirical relationship between TC characteristics and loss data. Another is to model the physical mechanism of TC-induced damage. In this talk we discuss about the physically-based approach to predict TC damage and losses due to extreme wind and storm surge. We first present an integrated vulnerability model, which, for the first time, explicitly models the essential mechanisms causing wind damage to residential areas during storm passage, including windborne-debris impact and the pressure-debris interaction that may lead, in a chain reaction, to structural failures (Lin and Vanmarcke 2010; Lin et al. 2010a). This model can be used to predict the economic losses in a residential neighborhood (with hundreds of buildings) during a specific TC (Yau et al. 2011) or applied jointly with a TC risk model (e.g., Emanuel et al 2008) to estimate the expected losses over long time periods. Then we present a TC storm surge risk model that has been applied to New York City (Lin et al. 2010b; Lin et al. 2012; Aerts et al. 2012), Miami-Dade County, Florida (Klima et al. 2011), Galveston, Texas (Lickley, 2012), and other coastal areas around the world (e.g., Tampa, Florida; Persian Gulf; Darwin, Australia; Shanghai, China). These physically-based models are applicable to various coastal areas and have the capability to account for the change of the climate and coastal exposure over time. We also point out that, although made computationally efficient for risk assessment, these models are not suitable for regional or global analysis, which has been a focus of the empirically-based economic analysis (e.g., Hsiang and Narita 2012). A future research direction is to simplify the physically-based models, possibly through parameterization, and make connections to the global loss data and economic analysis.

Unrepaired clustered DNA lesions induce chromosome breakage in human cells

PubMed Central

Asaithamby, Aroumougame; Hu, Burong; Chen, David J.

2011-01-01

Clustered DNA damage induced by ionizing radiation is refractory to repair and may trigger carcinogenic events for reasons that are not well understood. Here, we used an in situ method to directly monitor induction and repair of clustered DNA lesions in individual cells. We showed, consistent with biophysical modeling, that the kinetics of loss of clustered DNA lesions was substantially compromised in human fibroblasts. The unique spatial distribution of different types of DNA lesions within the clustered damages, but not the physical location of these damages within the subnuclear domains, determined the cellular ability to repair the damage. We then examined checkpoint arrest mechanisms and yield of gross chromosomal aberrations. Induction of nonrepairable clustered damage affected only G2 accumulation but not the early G2/M checkpoint. Further, cells that were released from the G2/M checkpoint with unrepaired clustered damage manifested a spectrum of chromosome aberrations in mitosis. Difficulties associated with clustered DNA damage repair and checkpoint release before the completion of clustered DNA damage repair appear to promote genome instability that may lead to carcinogenesis. PMID:21527720

UV Radiation: a new first year physics/life sciences laboratory experiment

NASA Astrophysics Data System (ADS)

Petelina, S. V.; Siddaway, J. M.

2010-12-01

Unfortunately, Australia leads the world in the number of skin cancer cases per capita. Three major factors that contribute to this are: 1) the level of damaging ultraviolet (UV) radiation in Australia is higher than in many other countries. This is caused, among other factors, by the stratospheric ozone depletion and Antarctic ozone hole; 2) many people in Australia are of Irish-Scottish origin and their skin can not repair the damage caused by the UV radiation as effectively as the skin of people of other origins; 3) Australia is one of the world’s leaders in the outdoor activities where people tend to spend more time outside. As our experience has shown, most Australian University students, high school students, and even high school teachers were largely unaware of the UV damage details and effective safety measures. Therefore, a need for new ways to educate people became apparent. The general aim of this new 1st year laboratory experiment, developed and first offered at La Trobe University (Melbourne, Australia) in 2009, is to investigate how UV-B radiation levels change under various solar illumination conditions and how effective different types of protection are. After pre-lab readings on physical concepts and biological effects of UV radiation, and after solving all pre-lab problems, the students go outside and measure the actual change in UV-B and UV-A radiation levels under various conditions. Some of these conditions are: direct sun, shade from a building, shade under the roof, reflection from various surfaces, direct sun through cheap and expensive sunglasses and eyeglasses, direct sun through various types of cloth and hair. The equipment used is the UV-Probe manufactured by sglux SolGel Technologies GmbH. The students’ feedback on this new laboratory experiment was very positive. It was ranked top among all physics experiments offered as part of that subject (Physics for Life Sciences) in 2009 and top among all physics experiments presented for peer evaluation at the Advanced Science Education Learning Laboratory Workshop in April 2010 at the University of Adelaide, Australia. All three main components of the UV Radiation experiment - pre-lab exercises, taking measurements, and a group discussion led by a demonstrator, were assessed by the students and by the teaching academics as a very important and valuable contribution to learning.

Understanding Femtosecond-Pulse Laser Damage through Fundamental Physics Simulations

NASA Astrophysics Data System (ADS)

Mitchell, Robert A., III

It did not take long after the invention of the laser for the field of laser damage to appear. For several decades researchers have been studying how lasers damage materials, both for the basic scientific understanding of highly nonequilibrium processes as well as for industrial applications. Femtosecond pulse lasers create little collateral damage and a readily reproducible damage pattern. They are easily tailored to desired specifications and are particularly powerful and versatile tools, contributing even more industrial interest in the field. As with most long-standing fields of research, many theoretical tools have been developed to model the laser damage process, covering a wide range of complexities and regimes of applicability. However, most of the modeling methods developed are either too limited in spatial extent to model the full morphology of the damage crater, or incorporate only a small subset of the important physics and require numerous fitting parameters and assumptions in order to match values interpolated from experimental data. Demonstrated in this work is the first simulation method capable of fundamentally modeling the full laser damage process, from the laser interaction all the way through to the resolidification of the target, on a large enough scale that can capture the full morphology of the laser damage crater so as to be compared directly to experimental measurements instead of extrapolated values, and all without any fitting parameters. The design, implementation, and testing of this simulation technique, based on a modified version of the particle-in-cell (PIC) method, is presented. For a 60 fs, 1 mum wavelength laser pulse with fluences of 0.5 J/cm 2, 1.0 J/cm2, and 2.0 J/cm2 the resulting laser damage craters in copper are shown and, using the same technique applied to experimental crater morphologies, a laser damage fluence threshold is calculated of 0.15 J/cm2, consistent with current experiments performed under conditions similar to those in the simulation. Lastly, this method is applied to the phenomenon known as LIPSS, or Laser-Induced Periodic Surface Structures; a problem of fundamental importance that is also of great interest for industrial applications. While LIPSS have been observed for decades in laser damage experiments, the exact physical mechanisms leading to the periodic corrugation on the surface of a target have been highly debated, with no general consensus. Applying this technique to a situation known to create LIPSS in a single shot, the generation of this periodicity is observed, the wavelength of the damage is consistent with experimental measures and, due to the fundamental nature of the simulation method, the physical mechanisms behind LIPSS are examined. The mechanism behind LIPSS formation in the studied regime is shown to be the formation of and interference with an evanescent surface electromagnetic wave known as a surface plasmon-polariton. This shows that not only can this simulation technique model a basic laser damage situation, but it is also flexible and powerful enough to be applied to complex areas of research, allowing for new physical insight in regimes that are difficult to probe experimentally.

The Intertwined Roles of Transcription and Repair Proteins

PubMed Central

Fong, Yick W.; Cattoglio, Claudia; Tjian, Robert

2014-01-01

Transcription is apparently risky business. Its intrinsic mutagenic potential must be kept in check by networks of DNA repair factors that monitor the transcription process to repair DNA lesions that could otherwise compromise transcriptional fidelity and genome integrity. Intriguingly, recent studies point to an even more direct function of DNA repair complexes as co-activators of transcription and the unexpected role of “scheduled” DNA damage/repair at gene promoters. Paradoxically, spontaneous DNA double-strand breaks also induce ectopic transcription that is essential for repair. Thus, transcription, DNA damage and repair may be more physically and functionally intertwined than previously appreciated. PMID:24207023

Cytogenetic Biodosimetry Using the Blood Lymphocytes of Astronauts

NASA Technical Reports Server (NTRS)

George, Kerry; Rhone, J.; Chappell, L. J.; Cucinotta, F. A.

2010-01-01

Cytogenetic analysis of blood lymphocytes remains the most sensitive and reliable method available for in vivo assessment of the biological effects of exposure to radiation and provides the most informative measurement of radiation induced health risks. To date chromosome damage has been assessed in lymphocytes from more than 30 astronauts before and after they participated in long-duration space missions of three months or more on board the International Space Station. For all individuals, the frequency of chromosome damage measured within a month of return from space was higher than their prefight yield and biodosimetry estimates lie within the range expected from physical dosimetry. Biodosimetry data provides a direct measurement of space radiation damage, which takes into account individual radiosensitivity in the presence of confounding factors such as microgravity and other stress conditions. In contrast to physical measurements, which are external to body and require multiple devices to detect all radiation types all of which have poor sensitivity to neutrons, biodosimetry is internal and includes the effects of shielding provided by the body itself plus chromosome damage shows excellent sensitivity to protons, heavy ions, and neutrons. In addition, chromosome damage is reflective of cancer risk and biodosimetry values can therefore be used to validate and develop risk assessment models that can be used to characterize excess health risk incurred by crewmembers. A review of astronaut biodosimetry data will be presented along with recent findings on the persistence of space radiation induced chromosome damage and the cytogenetic effects of repeat long duration missions

A comparative assessment of different frequency based damage detection in unidirectional composite plates using MFC sensors

NASA Astrophysics Data System (ADS)

de Medeiros, Ricardo; Sartorato, Murilo; Vandepitte, Dirk; Tita, Volnei

2016-11-01

The basic concept of the vibration based damage identification methods is that the dynamic behaviour of a structure can change if damage occurs. Damage in a structure can alter the structural integrity, and therefore, the physical properties like stiffness, mass and/or damping may change. The dynamic behaviour of a structure is a function of these physical properties and will, therefore, directly be affected by the damage. The dynamic behaviour can be described in terms of time, frequency and modal domain parameters. The changes in these parameters (or properties derived from these parameters) are used as indicators of damage. Hence, this work has two main objectives. The first one is to provide an overview of the structural vibration based damage identification methods. For this purpose, a fundamental description of the structural vibration based damage identification problem is given, followed by a short literature overview of the damage features, which are commonly addressed. The second objective is to create a damage identification method for detection of the damage in composite structures. To aid in this process, two basic principles are discussed, namely the effect of the potential damage case on the dynamic behaviour, and the consequences involved with the information reduction in the signal processing. Modal properties from the structural dynamic output response are obtained. In addition, experimental and computational results are presented for the application of modal analysis techniques applied to composite specimens with and without damage. The excitation of the structures is performed using an impact hammer and, for measuring the output data, accelerometers as well as piezoelectric sensors. Finite element models are developed by shell elements, and numerical results are compared to experimental data, showing good correlation for the response of the specimens in some specific frequency range. Finally, FRFs are analysed using suitable metrics, including a new one, which are compared in terms of their capability for damage identification. The experimental and numerical results show that the vibration-based damage methods combined to the metrics can be used in Structural Health Monitoring (SHM) systems to identify the damage in the structure.

Kinetic Damage from Meteorites

NASA Technical Reports Server (NTRS)

Cooke, William; Brown, Peter; Matney, Mark

2017-01-01

A Near Earth object impacting into Earth's atmosphere may produce damaging effects at the surface due to airblast, thermal pulse, or kinetic impact in the form of meteorites. At large sizes (>many tens of meters), the damage is amplified by the hypersonic impact of these large projectiles moving with cosmic velocity, leaving explosively produced craters. However, much more common is simple "kinetic" damage caused by the impact of smaller meteorites moving at terminal speeds. As of this date a handful of instances are definitively known of people or structures being directly hit and/or damaged by the kinetic impact of meteorites. Meteorites known to have struck humans include the Sylacauga, Alabama fall (1954) and the Mbale meteorite fall (1992). Much more common is kinetic meteorite damage to cars, buildings, and even a post box (Claxton, Georgia - 1984). Historical accounts indicate that direct kinetic damage by meteorites may be more common than recent accounts suggest (Yau et al., 1994). In this talk we will examine the contemporary meteorite flux and estimate the frequency of kinetic damage to various structures, as well as how the meteorite flux might affect the rate of human casualties. This will update an earlier study by Halliday et al (1985), adding variations expected in meteorite flux with latitude (Le Feuvre and Wieczorek, 2008) and validating these model predictions of speed and entry angle with observations from the NASA and SOMN fireball networks. In particular, we explore the physical characteristics of bright meteors which may be used as a diagnostic for estimating which fireballs produce meteorites and hence how early warning of such kinetic damage may be estimated in advance through observations and modelling.

Kinetic Damage from Meteorites

NASA Technical Reports Server (NTRS)

Cooke, William; Brown, Peter; Matney, Mark

2017-01-01

A Near Earth object impacting into Earth's atmosphere may produce damaging effects at the surface due to airblast, thermal pulse, or kinetic impact in the form of meteorites. At large sizes (greater than many tens of meters), the damage is amplified by the hypersonic impact of these large projectiles moving with cosmic velocity, leaving explosively produced craters. However, much more common is simple "kinetic" damage caused by the impact of smaller meteorites moving at terminal speeds. As of this date a handful of instances are definitively known of people or structures being directly hit and/or damaged by the kinetic impact of meteorites. Meteorites known to have struck humans include the Sylacauga, Alabama fall (1954) and the Mbale meteorite fall (1992). Much more common is kinetic meteorite damage to cars, buildings, and even a post box (Claxton, Georgia - 1984). Historical accounts indicate that direct kinetic damage by meteorites may be more common than recent accounts suggest (Yau et al., 1994). In this talk we will examine the contemporary meteorite flux and estimate the frequency of kinetic damage to various structures, as well as how the meteorite flux might affect the rate of human casualties. This will update an earlier study by Halliday et al (1985), adding variations expected in meteorite flux with latitude (Le Feuvre and Wieczorek, 2008) and validating these model predictions of speed and entry angle with observations from the NASA and SOMN fireball networks. In particular, we explore the physical characteristics of bright meteors which may be used as a diagnostic for estimating which fireballs produce meteorites and hence how early warning of such kinetic damage may be estimated in advance through observations and modeling.

Physics-based Entry, Descent and Landing Risk Model

NASA Technical Reports Server (NTRS)

Gee, Ken; Huynh, Loc C.; Manning, Ted

2014-01-01

A physics-based risk model was developed to assess the risk associated with thermal protection system failures during the entry, descent and landing phase of a manned spacecraft mission. In the model, entry trajectories were computed using a three-degree-of-freedom trajectory tool, the aerothermodynamic heating environment was computed using an engineering-level computational tool and the thermal response of the TPS material was modeled using a one-dimensional thermal response tool. The model was capable of modeling the effect of micrometeoroid and orbital debris impact damage on the TPS thermal response. A Monte Carlo analysis was used to determine the effects of uncertainties in the vehicle state at Entry Interface, aerothermodynamic heating and material properties on the performance of the TPS design. The failure criterion was set as a temperature limit at the bondline between the TPS and the underlying structure. Both direct computation and response surface approaches were used to compute the risk. The model was applied to a generic manned space capsule design. The effect of material property uncertainty and MMOD damage on risk of failure were analyzed. A comparison of the direct computation and response surface approach was undertaken.

Shear Wave Generation by Explosions in Anisotropic Crystalline Rock

NASA Astrophysics Data System (ADS)

Rogers-Martinez, M. A.; Sammis, C. G.; Stroujkova, A. F.

2015-12-01

The use of seismic waves to discriminate between earthquakes and underground explosions is complicated by the observation that explosions routinely radiate strong S waves. Whether these S waves are primarily generated by non-linear processes at the source, or by mode conversions and scattering along the path remains an open question. It has been demonstrated that S waves are generated at the source by any mechanism that breaks the spherical symmetry of the explosion. Examples of such mechanisms include tectonic shear stress, spall, and anisotropy in the emplacement medium. Many crystalline rock massifs are transversely isotropic because they contain aligned fractures over a range of scales from microfractures at the grain scale (called the rift) to regional sets of joints. In this study we use a micromechanical damage mechanics to model the fracture damage patterns and seismic radiation generated by explosions in a material in which the initial distribution of fractures has a preferred direction. Our simulations are compared with a set of field experiments in a granite quarry in Barre, VT conducted by New England Research and Weston Geophysical. Barre granite has a strong rift plane of aligned microfractures. Our model captures two important results of these field studies: 1) the spatial extent of rock fracture and generation of S waves depends on the burn-rate of the explosion and 2) the resultant damage is anisotropic with most damage occurring in the preferred direction of the microfractures (the rift plane in the granite). The physical reason damage is enhanced in the rift direction is that the mode I stress intensity factor is large for each fracture in the array of parallel fractures in the rift plane. Tensile opening on the rift plane plus sliding on the preexisting fractures make strong non-spherical contributions to the moment tensor in the far-field.

Use of electronarcosis to immobilize juvenile and adult northern pike

USGS Publications Warehouse

Walker, M.K.; Yanke, E.A.; Gingerich, W.H.

1994-01-01

Electronarcosis, the immobilization of a fish after an electric current has been applied and discontinued, is a potential alternative to chemical anesthetics. Successful narcosis was defined as the immobilization of a fish for 1-15 min without causing physical damage. In the laboratory, AC successfully narcotized juvenile (13-19-cm standard length, SL) northern pike (Esox lucius) at selected voltages; however, AC voltages that produced narcosis or resulted in physical damage were variable and unpredictable. In contrast, 60-90-V pulsed DC (PDC) for 10-60 s successfully narcotized juvenile pike without inducing physical damage. Duration of narcosis was directly related to voltage and inversely related to fish length. In the hatchery, sexually mature northern pike (45-97 cm SL), collected from the Mississippi River, were successfully narcotized by 60-V PDC for 10 s. Duration of narcosis was unrelated to fish length or sex, and averaged 58 plus or minus 7 s (mean plus or minus SE). This allowed sufficient time to collect eggs or milt. All fish were swimming upright within 3 min after treatment, and no mortalities were observed over the next 24 h. Survival of eggs from fertilization to eye- up did not significantly differ between eggs collected from electronarcotized adults and adults anesthetized with MS-222 (tricaine methanesulfonate). Electronarcosis represents a possible alternative to chemical anesthetics for immobilizing northern pike broodstock without an apparent impact on egg survival.

Transient features and growth behavior of artificial cracks during the initial damage period.

PubMed

Ma, Bin; Wang, Ke; Lu, Menglei; Zhang, Li; Zhang, Lei; Zhang, Jinlong; Cheng, Xinbin; Wang, Zhanshan

2017-02-01

The laser damage of transmission elements contains a series of complex processes and physical phenomena. The final morphology is a crater structure with different sizes and shapes. The formation and development of the crater are also accompanied by the generation, extension, and submersion of cracks. The growth characteristics of craters and cracks are important in the thermal-mechanism damage research. By using pump-probe detection and an imaging technique with a nanosecond pulsewidth probe laser, we obtained the formation time of the crack structure in the radial and circumferential directions. We carried out statistical analysis in angle, number, and crack length. We further analyzed the relationship between cracks and stress intensity or laser irradiation energy as well as the crack evolution process and the inner link between cracks and pit growth. We used an artificial indentation defect to investigate the time-domain evolution of crack growth, growth speed, transient morphology, and the characteristics of crater expansion. The results can be used to elucidate thermal stress effects on cracks, time-domain evolution of the damage structure, and the damage growth mechanism.

Detailed Post-Soft Impact Progressive Damage Assessment for Hybrid Structure Jet Engines

NASA Technical Reports Server (NTRS)

Siddens, Aaron; Bayandor, Javid; Celestina, Mark L.

2014-01-01

Currently, certification of engine designs for resistance to bird strike is reliant on physical tests. Predictive modeling of engine structural damage has mostly been limited to evaluation of individual forward section components, such as fan blades within a fixed frame of reference, to direct impact with a bird. Such models must be extended to include interactions among engine components under operating conditions to evaluate the full extent of engine damage. This paper presents the results of a study aim to develop a methodology for evaluating bird strike damage in advanced propulsion systems incorporating hybrid composite/metal structures. The initial degradation and failure of individual fan blades struck by a bird were investigated. Subsequent damage to other fan blades and engine components due to resultant violent fan assembly vibrations and fragmentation was further evaluated. Various modeling parameters for the bird and engine components were investigated to determine guidelines for accurately capturing initial damage and progressive failure of engine components. Then, a novel hybrid structure modeling approach was investigated and incorporated into the crashworthiness methodology. Such a tool is invaluable to the process of design, development, and certification of future advanced propulsion systems.

75 FR 1301 - Damages Received on Account of Personal Physical Injuries or Physical Sickness; Hearing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-11

... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [REG-127270-06] RIN 1545-BF81 Damages Received on Account of Personal Physical Injuries or Physical Sickness; Hearing AGENCY: Internal... from gross income for amounts received on account of personal physical injuries or physical sickness...

Protected areas mitigate diseases of reef-building corals by reducing damage from fishing.

PubMed

Lamb, Joleah B; Williamson, David H; Russ, Garry R; Willis, Bette L

2015-09-01

Parks and protected areas have been instrumental in reducing anthropogenic sources of damage in terrestrial and aquatic environments. Pathogen invasion often succeeds physical wounding and injury, yet links between the reduction of damage and the moderation of disease have not been assessed. Here, we examine the utility of no-take marine reserves as tools for mitigating diseases that affect reef-building corals. We found that sites located within reserves had fourfold reductions in coral disease prevalence compared to non-reserve sites (80466 corals surveyed). Of 31 explanatory variables assessed, coral damage and the abundance of derelict fishing line best explained differences in disease assemblages between reserves and non-reserves. Unexpectedly, we recorded significantly higher levels of disease, coral damage, and derelict fishing line in non-reserves with fishing gear restrictions than in those without gear restrictions. Fishers targeting stocks perceived to be less depleted, coupled with enhanced site access from immediately adjacent boat moorings, may explain these unexpected patterns. Significant correlations between the distance from mooring sites and prevalence values for a ciliate disease known to infest wounded tissue (r = -0.65), coral damage (r = -0.64), and the abundance of derelict fishing line (r = -0.85) corroborate this interpretation. This is the first study to link disease with recreational use intensity in a park, emphasizing the need to evaluate the placement of closures and their direct relationship to ecosystem health. Since corals are modular, ecological processes that govern reproductive and competitive fitness are frequently related to colony surface area therefore, even low levels of cumulative tissue loss from progressing diseases pose significant threats to reef coral persistence. Disease mitigation through reductions in physical injury in areas where human activities are concentrated is another mechanism by which protected areas may improve ecosystem resilience in a changing climate.

Recent Advances and Future Opportunities to Address Challenges in Offloading Diabetic Feet: A Mini-Review.

PubMed

Crews, Ryan T; King, Abagayle L; Yalla, Sai V; Rosenblatt, Noah J

2018-01-16

Diabetic foot ulcers (DFU) are a substantial dilemma for geriatric individuals with diabetes. The breakdown in tissue associated with DFU is typically a result of repetitive cycles of physical stress placed on the feet during weight-bearing activity. Accordingly, a key tenet in healing as well as preventing DFU is the use of offloading footwear to redistribute physical stress away from high stress locations such as bony prominences. Over the last several years there has been a substantial amount of effort directed at better understanding and implementing the practice of offloading. A review of this work as well as relevant technological advances is presented in this paper. Specifically, we will discuss the following topics in association with offloading diabetic feet: achieving optimal offloading, dosing activity/physical stress, thermal monitoring to detect preulcerative tissue damage, adherence with offloading devices, and optimizing the user experience. In addition to presenting progress to date, potential directions for further advancement are discussed. © 2018 S. Karger AG, Basel.

Do heavy ions cause microlesions in cell membranes?

NASA Technical Reports Server (NTRS)

Koniarek, Jan P.; Worgul, Basil V.

1992-01-01

The microlesion question is investigated by monitoring the electrical potential difference across the endothelium of rat corneas in vitro before, during, and after irradiation. When the corneas were exposed to 1 Gy of Fe-56 ions (450 and 600 MeV/a.m.u.), no effect was detected on this parameter. These results suggest that direct physical damage to cell membranes, as predicted by the microlesion theory, does not take place.

Socio-economic vulnerability to natural hazards - proposal for an indicator-based model

NASA Astrophysics Data System (ADS)

Eidsvig, U.; McLean, A.; Vangelsten, B. V.; Kalsnes, B.; Ciurean, R. L.; Argyroudis, S.; Winter, M.; Corominas, J.; Mavrouli, O. C.; Fotopoulou, S.; Pitilakis, K.; Baills, A.; Malet, J. P.

2012-04-01

Vulnerability assessment, with respect to natural hazards, is a complex process that must consider multiple dimensions of vulnerability, including both physical and social factors. Physical vulnerability refers to conditions of physical assets, and may be modeled by the intensity and magnitude of the hazard, the degree of physical protection provided by the natural and built environment, and the physical robustness of the exposed elements. Social vulnerability refers to the underlying factors leading to the inability of people, organizations, and societies to withstand impacts from the natural hazards. Social vulnerability models can be used in combination with physical vulnerability models to estimate both direct losses, i.e. losses that occur during and immediately after the impact, as well as indirect losses, i.e. long-term effects of the event. Direct impact of a landslide typically includes casualties and damages to buildings and infrastructure while indirect losses may e.g. include business closures or limitations in public services. The direct losses are often assessed using physical vulnerability indicators (e.g. construction material, height of buildings), while indirect losses are mainly assessed using social indicators (e.g. economical resources, demographic conditions). Within the EC-FP7 SafeLand research project, an indicator-based method was proposed to assess relative socio-economic vulnerability to landslides. The indicators represent the underlying factors which influence a community's ability to prepare for, deal with, and recover from the damage associated with landslides. The proposed model includes indicators representing demographic, economic and social characteristics as well as indicators representing the degree of preparedness and recovery capacity. Although the model focuses primarily on the indirect losses, it could easily be extended to include more physical indicators which account for the direct losses. Each indicator is individually ranked from 1 (lowest vulnerability) to 5 (highest vulnerability) and weighted, based on its overall degree of influence. The indicator weights range from 1 (least influential) to 3 (most influential) and have been selected on the basis of expert judgment. The final vulnerability score is taken as the weighted average of the individual indicators. The method was applied for locations in Norway, Greece, France, Andorra and Romania. The purpose of the case studies was to compare vulnerability levels and to test and possibly improve the methodology. In the case studies, similar vulnerability scores were obtained for the locations in Norway, Andorra and France. A higher vulnerability score was obtained for the location in Greece, while the highest vulnerability score was obtained for the location in Romania. The higher score for the locations in Greece and Romania are mainly due to economic conditions and conditions regarding preparedness and recovery.

Ballistics reviews: mechanisms of bullet wound trauma.

PubMed

Maiden, Nicholas

2009-01-01

The location of an entrance wound (bullet placement) and the projectile path are the most important factors in causing significant injury or death following a shooting. The head followed by the torso are the most vulnerable areas, with incapacitation resulting from central nervous system (brain or cord) disruption, or massive organ destruction with hemorrhage. Tissue and organ trauma result from the permanent wound cavity caused by direct destruction by the bullet, and also from radial stretching of surrounding tissues causing a temporary wound cavity. The extent of tissue damage is influenced by the type of bullet, its velocity and mass, as well as the physical characteristics of the tissues. The latter includes resistance to strain, physical dimensions of an organ, and the presence or absence of surrounding anatomical constraints. Bullet shape and construction will also affect tissue damage and bullets which display greater yaw will be associated with increased temporary cavitation. Military bullet designs do not include bullets that will expand or flatten as these cause greater wound trauma and are regulated by convention.

For the greater goods? Ownership rights and utilitarian moral judgment.

PubMed

Millar, J Charles; Turri, John; Friedman, Ori

2014-10-01

People often judge it unacceptable to directly harm a person, even when this is necessary to produce an overall positive outcome, such as saving five other lives. We demonstrate that similar judgments arise when people consider damage to owned objects. In two experiments, participants considered dilemmas where saving five inanimate objects required destroying one. Participants judged this unacceptable when it required violating another's ownership rights, but not otherwise. They also judged that sacrificing another's object was less acceptable as a means than as a side-effect; judgments did not depend on whether property damage involved personal force. These findings inform theories of moral decision-making. They show that utilitarian judgment can be decreased without physical harm to persons, and without personal force. The findings also show that the distinction between means and side-effects influences the acceptability of damaging objects, and that ownership impacts utilitarian moral judgment. Copyright © 2014 Elsevier B.V. All rights reserved.

Application of Surface Protective Coating to Enhance Environment-Withstanding Property of the MEMS 2D Wind Direction and Wind Speed Sensor.

PubMed

Shin, Kyu-Sik; Lee, Dae-Sung; Song, Sang-Woo; Jung, Jae Pil

2017-09-19

In this study, a microelectromechanical system (MEMS) two-dimensional (2D) wind direction and wind speed sensor consisting of a square heating source and four thermopiles was manufactured using the heat detection method. The heating source and thermopiles of the manufactured sensor must be exposed to air to detect wind speed and wind direction. Therefore, there are concerns that the sensor could be contaminated by deposition or adhesion of dust, sandy dust, snow, rain, and so forth, in the air, and that the membrane may be damaged by physical shock. Hence, there was a need to protect the heating source, thermopiles, and the membrane from environmental and physical shock. The upper protective coating to protect both the heating source and thermopiles and the lower protective coating to protect the membrane were formed by using high-molecular substances such as SU-8, Teflon and polyimide (PI). The sensor characteristics with the applied protective coatings were evaluated.

A Computational Efficient Physics Based Methodology for Modeling Ceramic Matrix Composites (Preprint)

DTIC Science & Technology

2011-11-01

elastic range, and with some simple forms of progressing damage . However, a general physics-based methodology to assess the initial and lifetime... damage evolution in the RVE for all possible load histories. Microstructural data on initial configuration and damage progression in CMCs were...the damaged elements will have changed, hence, a progressive damage model. The crack opening for each crack type in each element is stored as a

14 CFR 25.1707 - System separation: EWIS.

Code of Federal Regulations, 2013 CFR

2013-01-01

... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

14 CFR 25.1707 - System separation: EWIS.

Code of Federal Regulations, 2014 CFR

2014-01-01

... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

14 CFR 25.1707 - System separation: EWIS.

Code of Federal Regulations, 2010 CFR

2010-01-01

... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

14 CFR 25.1707 - System separation: EWIS.

Code of Federal Regulations, 2012 CFR

2012-01-01

... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

14 CFR 25.1707 - System separation: EWIS.

Code of Federal Regulations, 2011 CFR

2011-01-01

... installed to ensure adequate physical separation and electrical isolation so that damage to circuits... ensure adequate physical separation and electrical isolation so that a fault in any one airplane power... minimize potential for abrasion/chafing, vibration damage, and other types of mechanical damage. ...

An association of cocoa consumption with improved physical fitness and decreased muscle damage and oxidative stress in athletes.

PubMed

González-Garrido, José A; García-Sánchez, José R; Garrido-Llanos, Silvia; Olivares-Corichi, Ivonne M

2017-04-01

Several studies have demonstrated the protective effects of cocoa consumption, due to its anti-inflammatory and antioxidant properties. Acute exercise induces oxidative stress and causes muscular damage during training. This study was designed to examine the effect of cocoa consumption on the markers of muscle damage, oxidative stress and physical fitness in professional soccer players. Fifteen players (15-18 years old) were included in the study. Biochemical parameters, markers of muscle damage and oxidative stress, and physical performance were evaluated before and after cocoa consumption. Biochemical parameters determined the healthy metabolic status of the study group; biomarkers of muscle and oxidative damage were measured in blood to establish muscle and redox status. However, high levels of biomarkers of muscle damage were detected. Interestingly, cocoa consumption decreased the muscle damage biomarkers of CK and LDH by 39.4% and 23.03%, respectively. The redox status was modified by a decrease in oxidative damage (carbonyl groups, 26.31%; thiol groups, 27.52%; MDA, 32.42%) and an increase in total antioxidant capacity (15.98%) and GSH-Px activity (26.37%). In addition, we observed an increase in physical performance by 4% in the Cooper Test. Our findings suggest that a short period of cocoa consumption could be useful in maintaining a good physical fitness, due to the favourable effects on muscle and redox status in athletes during exhaustive exercise.

Radiative property degradation of water impinging on thermally-controlled surfaces under space conditions.

NASA Technical Reports Server (NTRS)

Maples, D.; Spiller, M. H.; Maples, G.

1973-01-01

Review of the results of an investigation aimed at determining experimentally the directional monochromatic reflectance changes caused under high-vacuum space conditions by a water spray impinging on thermally controlled surfaces consisting of three paint specimens (Z93, S13G, and 92-007) and an aluminum foil. The first two paints and the aluminum foil suffered considerable physical damage, but only small changes resulted in the reflectance of the paints while the reflectance of the aluminum foil decreased with increase in exposure time to the water jet. Only the 92-007 Dow Corning paint retained the same physical and reflective characteristics.

Two examples of industrial applications of shock physics research

NASA Astrophysics Data System (ADS)

Sanai, Mohsen

1996-05-01

An in-depth understanding of shock physics phenomena has led to many industrial applications. Two recent applications discussed in this paper are a method for assessing explosion safety in industrial plants and a bomb-resistant luggage container for widebody aircraft. Our explosion safety assessment is based on frequent use of computer simulation of postulated accidents to model in detail the detonation of energetic materials, the formation and propagation of the resulting airblast, and the projection of fragments of known material and mass. Using a general load-damage analysis technique referred to as the pressure-impulse (PI) method, we have developed a PC-based computer algorithm that includes a continually expanding library of PI load and damage curves, which can predict and graphically display common structural damage modes and the response of humans to postulated explosion accidents. A second commercial application of shock physics discussed here is a bomb-resistant luggage container for widebody aircraft that can protect the aircraft from a terrorist bomb hidden inside the luggage. This hardened luggage container (HLC) relies on blast management and debris containment provided by a flexible flow-through blanket woven from threads made with a strong lightweight material, such as Spectra or Kevlar. This mitigation blanket forms a continuous and seamless shell around the sides of the luggage container that are parallel to the aircraft axis, leaving the two ends of the container unprotected. When an explosion occurs, the mitigation blanket expands into a nearly circular shell that contains the flying debris while directing the flow into the adjacent containers. The HLC concept has been demonstrated through full-scale experiments conducted at SRI. We believe that these two examples represent a broad class of potential industrial hazard applications of the experimental, analytical, and computational tools possessed by the shock physics community.

Minimum State Awareness for Resilient Control Systems Under Cyber-Attack

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

Kisner, Roger; Fugate, David L; McIntyre, Timothy J

2012-01-01

State awareness for a control system is the accurate knowledge of the internal states of the system realization. To maintain stable operation, a controller requires a certain degree of state awareness. By definition, a cyber-attacker decreases the state awareness by modifying or removing the information available to the operator and control system. By doing so, the attacker can directly cause damage to the physical system through the control system, or indirectly by causing the operator to react in a damaging manner to the false information. In a number of recent papers, detection and mitigation strategies have been proposed that assumemore » state awareness. The goal of the attacker to reduce or remove state awareness makes this assumption invalid for most situations. One of the central problems of resilient control is developing methods to retain sufficient state awareness to continue operation during a cyberattack. In this paper, we will define state awareness, discuss the consequences of loss of state awareness, and some potential research directions for maintaining state awareness.« less

Persecution-induced reduction in earning capacity of Holocaust victims: influence of psychiatric and somatic aspects.

PubMed

Müller, Helge; Seifert, Frank; Asemann, Rita; Schütz, Patricia; Maler, Juan-Manuel; Sperling, Wolfgang

2011-01-01

The incidence of mental and somatic sequelae is very high in the group of persons damaged by the Holocaust. Based on the sociomedical criteria prevailing in Germany, the assessment of persecution-induced reduction in earning capacity of Holocaust victims (vMdE) is mainly orientated towards direct Holocaust-induced somatic and mental sequelae but must also take into account the interaction of direct Holocaust-induced damage with subsequently acquired physical, mental, and psychosocial factors. The current medical evaluation is focused on the question whether persecution-induced symptoms are exacerbated by endogenous factors like mental or somatic diseases and/or exogenous factors like life events. In that case the grade of vMdE could be increased. Based on the synopsis of 56 Holocaust victims, we ascertained in this study that newly acquired somatic diseases and psychic morbidities contribute to an increase in persecution-induced mental complaints. Copyright © 2011 S. Karger AG, Basel.

MDI: integrity index of cytoskeletal fibers observed by AFM

NASA Astrophysics Data System (ADS)

Manghi, Massimo; Bruni, Luca; Croci, Simonetta

2016-06-01

The Modified Directional Index (MDI) is a form factor of the angular spectrum computed from the 2D Fourier transform of an image marking the prevalence of rectilinear features throughout the picture. We study some properties of the index and we apply it to AFM images of cell cytoskeleton regions featuring patterns of rectilinear nearly parallel actin filaments as in the case of microfilaments grouped in bundles. The analysis of AFM images through MDI calculation quantifies the fiber directionality changes which could be related to fiber damages. This parameter is applied to the images of Hs 578Bst cell line, non-tumoral and not immortalized human epithelial cell line, irradiated with X-rays at doses equivalent to typical radiotherapy treatment fractions. In the reported samples, we could conclude that the damages are mainly born to the membrane and not to the cytoskeleton. It could be interesting to test the parameter also using other kinds of chemical or physical agents.

Comparing simulations and test data of a radiation damaged charge-coupled device for the Euclid mission

NASA Astrophysics Data System (ADS)

Skottfelt, Jesper; Hall, David J.; Gow, Jason P. D.; Murray, Neil J.; Holland, Andrew D.; Prod'homme, Thibaut

2017-04-01

The visible imager instrument on board the Euclid mission is a weak-lensing experiment that depends on very precise shape measurements of distant galaxies obtained by a large charge-coupled device (CCD) array. Due to the harsh radiative environment outside the Earth's atmosphere, it is anticipated that the CCDs over the mission lifetime will be degraded to an extent that these measurements will be possible only through the correction of radiation damage effects. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signals through a radiation-damaged CCD. The software is based on Shockley-Read-Hall theory and is made to mimic the physical properties in the CCD as closely as possible. The code runs on a single electrode level and takes the three-dimensional trap position, potential structure of the pixel, and multilevel clocking into account. A key element of the model is that it also takes device specific simulations of electron density as a direct input, thereby avoiding making any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.

DNA DAMAGE QUANTITATION BY ALKALINE GEL ELECTROPHORESIS.

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

SUTHERLAND,B.M.; BENNETT,P.V.; SUTHERLAND, J.C.

2004-03-24

Physical and chemical agents in the environment, those used in clinical applications, or encountered during recreational exposures to sunlight, induce damages in DNA. Understanding the biological impact of these agents requires quantitation of the levels of such damages in laboratory test systems as well as in field or clinical samples. Alkaline gel electrophoresis provides a sensitive (down to {approx} a few lesions/5Mb), rapid method of direct quantitation of a wide variety of DNA damages in nanogram quantities of non-radioactive DNAs from laboratory, field, or clinical specimens, including higher plants and animals. This method stems from velocity sedimentation studies of DNAmore » populations, and from the simple methods of agarose gel electrophoresis. Our laboratories have developed quantitative agarose gel methods, analytical descriptions of DNA migration during electrophoresis on agarose gels (1-6), and electronic imaging for accurate determinations of DNA mass (7-9). Although all these components improve sensitivity and throughput of large numbers of samples (7,8,10), a simple version using only standard molecular biology equipment allows routine analysis of DNA damages at moderate frequencies. We present here a description of the methods, as well as a brief description of the underlying principles, required for a simplified approach to quantitation of DNA damages by alkaline gel electrophoresis.« less

11th International Conference of Radiation Research

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

NONE

1999-07-18

Topics discussed in the conference included the following: Radiation Physics, Radiation Chemistry and modelling--Radiation physics and dosimetry; Electron transfer in biological media; Radiation chemistry; Biophysical and biochemical modelling; Mechanisms of DNA damage; Assays of DNA damage; Energy deposition in micro volumes; Photo-effects; Special techniques and technologies; Oxidative damage. Molecular and cellular effects-- Photobiology; Cell cycle effects; DNA damage: Strand breaks; DNA damage: Bases; DNA damage Non-targeted; DNA damage: other; Chromosome aberrations: clonal; Chromosomal aberrations: non-clonal; Interactions: Heat/Radiation/Drugs; Biochemical effects; Protein expression; Gene induction; Co-operative effects; ``Bystander'' effects; Oxidative stress effects; Recovery from radiation damage. DNA damage and repair -- DNAmore » repair genes; DNA repair deficient diseases; DNA repair enzymology; Epigenetic effects on repair; and Ataxia and ATM.« less

Elephants in the understory: opposing direct and indirect effects of consumption and ecosystem engineering by megaherbivores.

PubMed

Coverdale, Tyler C; Kartzinel, Tyler R; Grabowski, Kathryn L; Shriver, Robert K; Hassan, Abdikadir A; Goheen, Jacob R; Palmer, Todd M; Pringle, Robert M

2016-11-01

Positive indirect effects of consumers on their resources can stabilize food webs by preventing overexploitation, but the coupling of trophic and non-trophic interactions remains poorly integrated into our understanding of community dynamics. Elephants engineer African savanna ecosystems by toppling trees and breaking branches, and although their negative effects on trees are well documented, their effects on small-statured plants remain poorly understood. Using data on 117 understory plant taxa collected over 7 yr within 36 1-ha experimental plots in a semi-arid Kenyan savanna, we measured the strength and direction of elephant impacts on understory vegetation. We found that elephants had neutral effects on most (83-89%) species, with a similar frequency of positive and negative responses among the remainder. Overall, estimated understory biomass was 5-14% greater in the presence of elephants across a range of rainfall levels. Whereas direct consumption likely accounts for the negative effects, positive effects are presumably indirect. We hypothesized that elephants create associational refuges for understory plants by damaging tree canopies in ways that physically inhibit feeding by other large herbivores. As predicted, understory biomass and species richness beneath elephant-damaged trees were 55% and 21% greater, respectively, than under undamaged trees. Experimentally simulated elephant damage increased understory biomass by 37% and species richness by 49% after 1 yr. Conversely, experimentally removing elephant damaged branches decreased understory biomass by 39% and richness by 30% relative to sham-manipulated trees. Camera-trap surveys revealed that elephant damage reduced the frequency of herbivory by 71%, whereas we detected no significant effect of damage on temperature, light, or soil moisture. We conclude that elephants locally facilitate understory plants by creating refuges from herbivory, which countervails the direct negative effects of consumption and enhances larger-scale biomass and diversity by promoting the persistence of rare and palatable species. Our results offer a counterpoint to concerns about the deleterious impacts of elephant "overpopulation" that should be considered in debates over wildlife management in African protected areas: understory species comprise the bulk of savanna plant biodiversity, and their responses to elephants are buffered by the interplay of opposing consumptive and non-consumptive interactions. © 2016 by the Ecological Society of America.

Recent corrections to meteoroid environment models

NASA Astrophysics Data System (ADS)

Moorhead, A.; Brown, P.; Campbell-Brown, M. D.; Moser, D. E.; Blaauw, R. C.; Cooke, W.

2017-12-01

The dynamical and physical characteristics of a meteoroid affects its behavior in the atmosphere and the damage it does to spacecraft surfaces. Accurate environment models must therefore correctly describe the speed, size, density, and direction of meteoroids. However, the measurement of dynamical characteristics such as speed is subject to observational biases, and physical properties such as size and density cannot be directly measured. De-biasing techniques and proxies are needed to overcome these challenges. In this presentation, we discuss several recent improvements to the derivation of the meteoroid velocity, directionality, and bulk density distributions. We derive our speed distribution from observations made by the Canadian Meteor Orbit Radar. These observations are de-biased using modern descriptions of the ionization efficiency and sharpened to remove the effects of measurement uncertainty, and the result is a meteoroid speed distribution that is skewed slower than in previous analyses. We also adopt a higher fidelity density distribution than that used by many older models. In our distribution, meteoroids with TJ < 2 are assigned to a low-density population, while those with TJ > 2 have higher densities. This division and the distributions themselves are derived from the densities reported by Kikwaya et al. (2009, 2011). These changes have implications for the environment. For instance, helion and antihelion meteors have lower speeds and higher densities than apex and toroidal meteors. A slower speed distribution therefore corresponds to a sporadic environment that is more completely dominated by the helion and antihelion sources than in previous models. Finally, assigning these meteors high densities further increases their significance from a spacecraft damage perspective.

Recent Corrections to Meteoroid Environment Models

NASA Technical Reports Server (NTRS)

Moorhead, A. V.; Brown, P. G.; Campbell-Brown, M. D.; Moser, D. E.; Blaauw, R. C.; Cooke, W. J.

2017-01-01

The dynamical and physical characteristics of a meteoroid affects its behavior in the atmosphere and the damage it does to spacecraft surfaces. Accurate environment models must therefore correctly describe the speed, size, density, and direction of meteoroids. However, the measurement of dynamical characteristics such as speed is subject to observational biases, and physical properties such as size and density cannot be directly measured. De-biasing techniques and proxies are needed to overcome these challenges. In this presentation, we discuss several recent improvements to the derivation of the meteoroid velocity, directionality, and bulk density distributions. We derive our speed distribution from observations made by the Canadian Meteor Orbit Radar. These observations are de-biased using modern descriptions of the ionization efficiency and sharpened to remove the effects of measurement uncertainty, and the result is a meteoroid speed distribution that is skewed slower than in previous analyses. We also adopt a higher fidelity density distribution than that used by many older models. In our distribution, meteoroids with T(sub J) less than 2 are assigned to a low-density population, while those with T(sub J) greater than 2 have higher densities. This division and the distributions themselves are derived from the densities reported by Kikwaya et al. (2009, 2011). These changes have implications for the environment. For instance, helion and antihelion meteors have lower speeds and higher densities than apex and toroidal meteors. A slower speed distribution therefore corresponds to a sporadic environment that is more completely dominated by the helion and antihelion sources than in previous models. Finally, assigning these meteors high densities further increases their significance from a spacecraft damage perspective.

Comparing simulations and test data of a radiation damaged CCD for the Euclid mission

NASA Astrophysics Data System (ADS)

Skottfelt, Jesper; Hall, David; Gow, Jason; Murray, Neil; Holland, Andrew; Prod'homme, Thibaut

2016-07-01

The radiation damage effects from the harsh radiative environment outside the Earth's atmosphere can be a cause for concern for most space missions. With the science goals becoming ever more demanding, the requirements on the precision of the instruments on board these missions also increases, and it is therefore important to investigate how the radiation induced damage affects the Charge-Coupled Devices (CCDs) that most of these instruments rely on. The primary goal of the Euclid mission is to study the nature of dark matter and dark energy using weak lensing and baryonic acoustic oscillation techniques. The weak lensing technique depends on very precise shape measurements of distant galaxies obtained by a large CCD array. It is anticipated that over the 6 year nominal lifetime of mission, the CCDs will be degraded to an extent that these measurements will not be possible unless the radiation damage effects are corrected. We have therefore created a Monte Carlo model that simulates the physical processes taking place when transferring signal through a radiation damaged CCD. The software is based on Shockley-Read-Hall theory, and is made to mimic the physical properties in the CCD as close as possible. The code runs on a single electrode level and takes charge cloud size and density, three dimensional trap position, and multi-level clocking into account. A key element of the model is that it takes device specific simulations of electron density as a direct input, thereby avoiding to make any analytical assumptions about the size and density of the charge cloud. This paper illustrates how test data and simulated data can be compared in order to further our understanding of the positions and properties of the individual radiation-induced traps.

The role of neutrophils in injury and repair following muscle stretch

PubMed Central

Toumi, Hechmi; F'guyer, Sleem; Best, Thomas M

2006-01-01

Stretch injury to the myotendinous junction is a common problem in competitive athletes and those involved in regular physical activity. The major risk factor for recurrent injury appears to be the primary injury itself. Physicians, physical therapists, athletic trainers and athletes alike continue to search for optimal treatment and prevention strategies. Acute inflammation is regarded as the body's generalized protective response to tissue injury. An especially important and unexplored aspect of inflammation following injury is the role of inflammatory cells in extending injury and possibly directing muscle repair. It has been suggested that the inflammatory reaction, although it typically represents a reaction to damage and necrosis, may even bring about some local damage of its own and therefore increase the possibility for scarring and fibrosis. Limiting certain aspects of inflammation may theoretically reduce muscle damage as well as signals for muscle scarring. Here we focus on the role of neutrophils in injury and repair of stretch-injured skeletal muscle. A minimally invasive model that generates a reproducible injury to rabbit skeletal muscle is presented. We present a plausible theory that neutrophil-derived oxidants resulting from the initial stretch injury are responsible for extending the damage. An anti-CD11b antibody that blocks the neutrophil's respiratory burst is employed to reduce myofibre damage. An intriguing area that is currently being explored in our laboratory and others is the potential role for neutrophils to contribute to muscle growth and repair. It may be possible that neutrophils facilitate muscle repair through removal of tissue debris as well as by activation of satellite cells. Recent and ongoing investigations point to interleukin-6 as a possible key cytokine in muscle inflammation and repair. Studies to elucidate a clearer understanding of this possibility will be reviewed. PMID:16637872

Effects of protein supplements on muscle damage, soreness and recovery of muscle function and physical performance: a systematic review.

PubMed

Pasiakos, Stefan M; Lieberman, Harris R; McLellan, Tom M

2014-05-01

Protein supplements are frequently consumed by athletes and recreationally-active individuals, although the decision to purchase and consume protein supplements is often based on marketing claims rather than evidence-based research. To provide a systematic and comprehensive analysis of literature examining the hypothesis that protein supplements enhance recovery of muscle function and physical performance by attenuating muscle damage and soreness following a previous bout of exercise. English language articles were searched with PubMed and Google Scholar using protein and supplements together with performance, exercise, competition and muscle, alone or in combination as keywords. Inclusion criteria required studies to recruit healthy adults less than 50 years of age and to evaluate the effects of protein supplements alone or in combination with carbohydrate on performance metrics including time-to-exhaustion, time-trial or isometric or isokinetic muscle strength and markers of muscle damage and soreness. Twenty-seven articles were identified of which 18 dealt exclusively with ingestion of protein supplements to reduce muscle damage and soreness and improve recovery of muscle function following exercise, whereas the remaining 9 articles assessed muscle damage as well as performance metrics during single or repeat bouts of exercise. Papers were evaluated based on experimental design and examined for confounders that explain discrepancies between studies such as dietary control, training state of participants, sample size, direct or surrogate measures of muscle damage, and sensitivity of the performance metric. High quality and consistent data demonstrated there is no apparent relationship between recovery of muscle function and ratings of muscle soreness and surrogate markers of muscle damage when protein supplements are consumed prior to, during or after a bout of endurance or resistance exercise. There also appears to be insufficient experimental data demonstrating ingestion of a protein supplement following a bout of exercise attenuates muscle soreness and/or lowers markers of muscle damage. However, beneficial effects such as reduced muscle soreness and markers of muscle damage become more evident when supplemental protein is consumed after daily training sessions. Furthermore, the data suggest potential ergogenic effects associated with protein supplementation are greatest if participants are in negative nitrogen and/or energy balance. Small sample numbers and lack of dietary control limited the effectiveness of several investigations. In addition, studies did not measure the effects of protein supplementation on direct indices of muscle damage such as myofibrillar disruption and various measures of protein signaling indicative of a change in rates of protein synthesis and degradation. As a result, the interpretation of the data was often limited. Overwhelmingly, studies have consistently demonstrated the acute benefits of protein supplementation on post-exercise muscle anabolism, which, in theory, may facilitate the recovery of muscle function and performance. However, to date, when protein supplements are provided, acute changes in post-exercise protein synthesis and anabolic intracellular signaling have not resulted in measureable reductions in muscle damage and enhanced recovery of muscle function. Limitations in study designs together with the large variability in surrogate markers of muscle damage reduced the strength of the evidence-base.

26 CFR 301.7433-1 - Civil cause of action for certain unauthorized collection actions.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) The actual, direct economic damages sustained as a proximate result of the reckless or international.... (b) Actual, direct economic damages—(1) Definition. Actual, direct economic damages are actual... and administrative costs are not recoverable as actual, direct economic damages. Litigation costs may...

Damage pattern as a function of radiation quality and other factors.

PubMed

Burkart, W; Jung, T; Frasch, G

1999-01-01

An understanding of damage pattern in critical cellular structures such as DNA is an important prerequisite for a mechanistic assessment of primary radiation damage, its possible repair, and the propagation of residual changes in somatic and germ cells as potential contributors to disease or ageing. Important quantitative insights have been made recently on the distribution in time and space of critical lesions from direct and indirect action of ionizing radiation on mammalian cells. When compared to damage from chemicals or from spontaneous degradation, e.g. depurination or base deamination in DNA, the potential of even low-LET radiation to create local hot spots of damage from single particle tracks is of utmost importance. This has important repercussions on inferences from critical biological effects at high dose and dose rate exposure situations to health risks at chronic, low-level exposures as experienced in environmental and controlled occupational settings. About 10,000 DNA lesions per human cell nucleus and day from spontaneous degradation and chemical attack cause no apparent effect, but a dose of 4 Gy translating into a similar number of direct and indirect DNA breaks induces acute lethality. Therefore, single lesions cannot explain the high efficiency of ionizing radiation in the induction of mutation, transformation and loss of proliferative capacity. Clustered damage leading to poorly repairable double-strand breaks or even more complex local DNA degradation, correlates better with fixed damage and critical biological endpoints. A comparison with other physical, chemical and biological agents indicates that ionizing radiation is indeed set apart from these by its unique micro- and nano-dosimetric traits. Only a few other agents such as bleomycin have a similar potential to cause complex damage from single events. However, in view of the multi-stage mechanism of carcinogenesis, it is still an open question whether dose-effect linearity for complex primary DNA damage and resulting fixed critical cellular lesions translate into linearity for radiation-induced cancer. To solve this enigma, a quantitative assessment of all genotoxic and harmful non-genotoxic agents affecting the human body would be needed.

Integrated flood damage modelling in the Ebro river basin under hydrodynamic, socio-economic and environmental factors

NASA Astrophysics Data System (ADS)

Foudi, S.; Galarraga, I.; Osés, N.

2012-04-01

This paper presents a model of flood damage measurement. It studies the socio-economic and environmental potential damage of floods in the Ebro river basin. We estimate the damage to the urban, rural and environmental sectors. In these sectors, we make distinctions between residential, non residential, cultural, agricultural, public facilities and utilities, environmental and human subsectors. We focus on both the direct, indirect, tangible and intangible impacts. The residential damages refer to the damages on housing, costs of repair and cleaning as direct effects and the re-housing costs as an indirect effect. The non residential and agricultural impacts concern the losses to the economic sectors (industry, business, agricultural): production, capital losses, costs of cleaning and repairs for the direct costs and the consequences of the suspension of activities for the indirect costs. For the human sector, we refer to the physical impacts (injuries and death) in the direct tangible effects and to the posttraumatic stress as indirect intangible impact. The environmental impacts focus on a site of Community Interests (pSCIs) in the case study area. The case study is located the Ebro river basin, Spain. The Ebro river basin is the larger river basin in term of surface and water discharge. The Ebro river system is subject to Atlantic and Mediterranean climatic influences. It gathers most of its water from the north of Spain (in the Pyrenees Mountains) and is the most important river basin of Spain in term of water resources. Most of the flooding occurs during the winter period. Between 1900- 2010, the National Catalogue of Historical Floods identifies 372 events: meanly 33 events every 10 years and up to 58 during the 1990-2000. Natural floods have two origins: (i) persistent rainfalls in large sub basins raised up by high temperature giving rise to a rapid thaw in the Pyrenees, (ii) local rainfalls of short duration and high intensity that gives rise to rapid and wrenching floods. Our integrated model combines hydrologic, land use, environmental and economic data. The combination of the cadastral data with the flood characteristics (flow, depth, duration) for various periods of return enables to draw damage maps expressed as function of flood characteristics (Penning-Rowsell et al. 2005). This methodology also enables to illustrate consequences of risk prevention measures. We can thus measure the value of information in the alert system of Civil Protection Agency, give information on risks for urban development plans and simulate the consequences of hydraulic interventions like river bed cleaning. This methodology would then contribute to match with the requirements of the 2007 EU flood risk Management Directive (2007/60/CE).

PCNA-dependent accumulation of CDKN1A into nuclear foci after ionizing irradiation

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

Wiese, Claudia; Rudolph, Jeanette Heede; Jakob, Burkhard

2012-03-26

The cyclin-dependent kinase inhibitor CDKN1A/p21 confers cell-cycle arrest in response to DNA damage and inhibits DNA replication through its direct interaction with the proliferating cell nuclear antigen (PCNA) and cyclin/cyclin-dependent kinase complexes. Previously, we reported that in response to densely ionizing radiation CDKN1A rapidly is recruited to the sites of particle traversal, and that CDKN1A foci formation in response to heavy ions is independent of its transactivation by TP53. In this paper, we show that exposure of normal human fibroblasts to X-rays or to H 2O 2 also induces nuclear accumulations of CDKN1A. We find that CDKN1A foci formation inmore » response to radiation damage is dependent on its dephosphorylation and on its direct physical interaction with PCNA. Live cell imaging analyses of ectopically expressed EGFP-CDKN1A and dsRed-PCNA show rapid recruitment of both proteins into foci after radiation damage. Detailed dynamic measurements reveal a slightly delayed recruitment of CDKN1A compared to PCNA, which is best described by bi-exponential curve fitting, taking the preceding binding of PCNA to DNA into account. Finally, we propose a regulatory role for CDKN1A in mediating PCNA function after radiation damage, and provide evidence that this role is distinct from its involvement in nucleotide excision repair and unrelated to double-strand break repair.« less

Characterization of the Fault Core and Damage Zone of the Borrego Fault, 2010 M7.2 Rupture

NASA Astrophysics Data System (ADS)

Dorsey, M. T.; Rockwell, T. K.; Girty, G.; Ostermeijer, G.; Mitchell, T. M.; Fletcher, J. M.

2017-12-01

We collected a continuous sample of the fault core and 23 samples of the damage zone out to 52 m across the rupture trace of the 2010 M7.2 El Mayor-Cucapa earthquake to characterize the physical damage and chemical transformations associated with this active seismic source. In addition to quantifying fracture intensity from macroscopic analysis, we cut a continuous thin section through the fault core and from various samples in the damage zone, and ran each sample for XRD analyses for clay mineralogy, XRF for bulk geochemical analyses, and bulk and grain density from which porosity and volumetric strain were derived. The parent rock is a hydrothermally-altered biotite tonalite, with biotite partially altered to chlorite. The presence of epidote with chlorite suggests that these rocks were subjected to relatively high temperatures of 300-400° C. Adjacent to the outermost damage zone is a chaotic breccia zone with distinct chemical and physical characteristics, indicating possible connection to an ancestral fault to the southwest. The damage zone consists of an outer zone of protocataclasite, which grades inward towards mesocataclasite with seams of ultracataclasite. The fault core is anomalous in that it is largely composed of a sliver of marble that has been translated along the fault, so direct comparison with the damage zone is impaired. From collected data, we observe that chloritization increases into the breccia and damage zones, as does the presence of illite. Porosity reaches maximum values in the damage zone adjacent to the core, and closely follows trends in fracture intensity. Statistically significant gains in Mg, Na, K, Mn, and total bulk mass occurred within the inner damage zone, with losses of Ca and P mass, which led to the formation of chlorite and albite. The outer damage zone displays gains in Mg and Na mass with losses in Ca and P mass. The breccia zone shows gains in mass of Mg and Mn and loss in total bulk mass. A gain in LOI in both the breccia and damage zones is attributed to formation of clay. Volumetric strain tracks porosity, as expected, and increases towards the core. Notably, damage appears to be superposed on chemical alterations, which supports the idea that much of the hydrothermal alteration occurred at depth followed by brecciation and cataclasis once the fault zone rocks were exhumed closer to the surface.

Physical Exercise Promotes Recovery of Neurological Function after Ischemic Stroke in Rats

PubMed Central

Zheng, Hai-Qing; Zhang, Li-Ying; Luo, Jing; Li, Li-Li; Li, Menglin; Zhang, Qingjie; Hu, Xi-Quan

2014-01-01

Although physical exercise is an effective strategy for treatment of ischemic stroke, the underlying protective mechanisms are still not well understood. It has been recently demonstrated that neural progenitor cells play a vital role in the recovery of neurological function (NF) through differentiation into mature neurons. In the current study, we observed that physical exercise significantly reduced the infarct size and improved damaged neural functional recovery after an ischemic stroke. Furthermore, we found that the treatment not only exhibited a significant increase in the number of neural progenitor cells and neurons but also decreased the apoptotic cells in the peri-infarct region, compared to a control in the absence of exercise. Importantly, the insulin-like growth factor-1 (IGF-1)/Akt signaling pathway was dramatically activated in the peri-infarct region of rats after physical exercise training. Therefore, our findings suggest that physical exercise directly influences the NF recovery process by increasing neural progenitor cell count via activation of the IGF-1/Akt signaling pathway. PMID:24945308

Rudolf Mössbauer in Munich

NASA Astrophysics Data System (ADS)

Kalvius, G. M.; Kienle, P.

Mössbauer and one of the authors (PK) started in 1949 studying physics at the Technische Hochschule München (THM), which was still under reconstruction from the war damages. It offered two directions for studying physics: "Physik A" and "Physik B." I took courses in "Physik A," which meant Technical Physics; Mössbauer studied "Physik B," which was General Physics. Actually, the lectures of both directions were not too different up to the forth semester, followed by a "pre-diploma" examination, which Mössbauer passed in 1952. I as "Physik A" student had besides the various physics, chemistry, and mathematics courses, in addition lectures in Technical Electricity, Technical Mechanics, Technical Thermodynamics, and later Measurement Engineering offered by very famous professors, such as W.O. Schumann, L. Föppl, W. Nußelt, and H. Piloty. Our physics teachers were G. Joos (Experimental physics), G. Hettner (Theoretical Physics), and W. Meissner (Technical Physics); in mathematics, we enjoyed lectures by J. Lense and R. Sauer, and interesting chemistry lectures by W. Hieber. Thus we received a high-class classical education, but quantum mechanics was not a compulsory subject. Mössbauer complained about this deficiency when he realized that the effect he found was a quantum mechanical phenomenon. Quantum mechanics was offered as an optional subject by Prof. Fick and Prof. Haug. Mössbauer just missed to take these advanced lectures, although he was highly talented in mathematics and received even a tutoring position in the mathematics institute of Prof. R. Sauer, while I worked in engineering projects and had extensive industrial training.

Physical protection philosophy and techniques in Sweden

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

Dufva, B.

1988-01-01

The circumstances for the protection of nuclear power plants are special in Sweden. A very important factor is that armed guards at the facilities are alien to the Swedish society. They do not use them. The Swedish concept of physical protection accepts that the aggressor will get into the facility. With this in mind, the Swedish Nuclear Power Inspectorate (SKI) has established the policy that administrative, technical, and organizational measures will be directed toward preventing an aggressor from damaging the reactor, even if he has occupied the facility. In addition, the best conditions possible shall be established for the operatormore » and the police to reoccupy the plant. The author believes this policy is different from that of many other countries. Therefore, he focusses on the Swedish philosophy and techniques for the physical protection of nuclear power plants.« less

The Groot Effect: Plant facilitation and desert shrub regrowth following extensive damage.

PubMed

Lortie, Christopher J; Gruber, Eva; Filazzola, Alex; Noble, Taylor; Westphal, Michael

2018-01-01

Deserts are increasing in extent globally, but existing deserts are decreasing in health. The basic biology and ecology of foundation plant species in deserts are limited. This is a direct study that provides an estimate of the capacity for a locally dominant foundation shrub species in California to recover from damage. Desert shrubs are cleared and damaged by humans for many purposes including agriculture, oil and gas production, and sustainable energy developments; we need to know whether foundation species consistently facilitate the abundance and diversity of other plants in high-stress ecosystems and whether they can recover. A total of 20 Ephedra californica shrubs were clipped to the ground at a single site and systematically resampled for regrowth 2 years later. These shrubs were damaged once and regrew rapidly, and relatively, larger shrubs were not more resilient. This study provides evidence for what we termed the "Groot Effect" because smaller individuals of this shrub species can recover from significant aboveground damage and continue to have positive effects on other plant species (similar to the popular culture reference to a benefactor tree species). The density of other plant species was consistently facilitated while effects on diversity varied with season. These findings confirm that E. californica is a foundation species that can be an important restoration tool within the deserts of California in spite of extreme cycles of drought and physical damage to its canopy.

Hippo pathway and protection of genome stability in response to DNA damage.

PubMed

Pefani, Dafni E; O'Neill, Eric

2016-04-01

The integrity of DNA is constantly challenged by exposure to the damaging effects of chemical and physical agents. Elucidating the cellular mechanisms that maintain genomic integrity via DNA repair and cell growth control is vital because errors in these processes lead to genomic damage and the development of cancer. By gaining a deep molecular understanding of the signaling pathways regulating genome integrity it is hoped to uncover new therapeutics and treatment designs to combat cancer. Components of the Hippo pathway, a tumor-suppressor cascade, have recently been defined to limit cancer transformation in response to DNA damage. In this review, we briefly introduce the Hippo signaling cascade in mammals and discuss in detail how the Hippo pathway has been established as part of the DNA damage response, activated by apical signaling kinases that recognize breaks in DNA. We also highlight the significance of the Hippo pathway activator RASSF1A tumor suppressor, a direct target of ataxia telangiectasia mutated and ataxia telangiectasia and Rad3 related ATR. Furthermore we discuss how Hippo pathway in response DNA lesions can induce cell death via Yes-associated protein (YAP) (the canonical Hippo pathway effector) or promote maintenance of genome integrity in a YAP-independent manner. © 2015 FEBS.

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

Shin, J; Park, S; Jeong, J

Purpose: In particle therapy and radiobiology, the investigation of mechanisms leading to the death of target cancer cells induced by ionising radiation is an active field of research. Recently, several studies based on Monte Carlo simulation codes have been initiated in order to simulate physical interactions of ionising particles at cellular scale and in DNA. Geant4-DNA is the one of them; it is an extension of the general purpose Geant4 Monte Carlo simulation toolkit for the simulation of physical interactions at sub-micrometre scale. In this study, we present Geant4-DNA Monte Carlo simulations for the prediction of DNA strand breakage usingmore » a geometrical modelling of DNA structure. Methods: For the simulation of DNA strand breakage, we developed a specific DNA geometrical structure. This structure consists of DNA components, such as the deoxynucleotide pairs, the DNA double helix, the nucleosomes and the chromatin fibre. Each component is made of water because the cross sections models currently available in Geant4-DNA for protons apply to liquid water only. Also, at the macroscopic-scale, protons were generated with various energies available for proton therapy at the National Cancer Center, obtained using validated proton beam simulations developed in previous studies. These multi-scale simulations were combined for the validation of Geant4-DNA in radiobiology. Results: In the double helix structure, the deposited energy in a strand allowed to determine direct DNA damage from physical interaction. In other words, the amount of dose and frequency of damage in microscopic geometries was related to direct radiobiological effect. Conclusion: In this report, we calculated the frequency of DNA strand breakage using Geant4- DNA physics processes for liquid water. This study is now on-going in order to develop geometries which use realistic DNA material, instead of liquid water. This will be tested as soon as cross sections for DNA material become available in Geant4-DNA.« less

Electronmicroscopic observations on the effects of orally administered aspirin and aspirin-bicarbonate mixtures on the development of gastric mucosal damage in the rat.

PubMed Central

Rainsford, K D

1975-01-01

The effects of administering a single dose of (200 mg to 50 mg/kg body weight) aspirin or an equimolar mixture of aspirin (200 mg/kg body wt) with sodium bicarbonate on the fine structure of the rat gastric mucosa were investigated in order to establish the role of particles of the drug in the development of gastric damage. The sequence of cellular events involved in the development of a lesion and the influence of short-term starvation were also investigated. Aspirin-bicarbonate solutions produced much less damage in starved rats than aspirin suspensions given at low (50 mg/kg body weight) or high therapeutic doses (200 mg/kg body weight). Also, when non-starved rats were given 200 mg/kg aspirin, only slight damage was observed. The presence of particles of the drug in intimate contact with the mucosa is thus important in the development of gastric damage. A sequence of events with time involving direct physical exfoliation of mucosal cells and selective structural damage to parietal cells followed by structural damage indicative of a disturbance to oxidative and biosynthetic functions in cells near the developing erosion was observed. The implications of these results on the development of aspirin-induced lesions are discussed. Images Fig 3a Fig 3b Fig 1a Fig 1b Fig 1c Fig 2a Fig 2b Fig 4 Fig 5 PMID:1158188

Multiscale approach to the physics of radiation damage with ions

NASA Astrophysics Data System (ADS)

Surdutovich, Eugene; Solov'yov, Andrey V.

2013-04-01

We review a multiscale approach to the physics of ion-beam cancer therapy, an approach suggested in order to understand the interplay of a large number of phenomena involved in radiation damage scenario occurring on a range of temporal, spatial, and energy scales. We briefly overview its history and present the current stage of its development. The differences of the multiscale approach from other methods of understanding and assessment of radiation damage are discussed as well as its relationship to other branches of physics, chemistry and biology.

Structural Health Management of Damaged Aircraft Structures Using the Digital Twin Concept

NASA Technical Reports Server (NTRS)

Seshadri, Banavara R.; Krishnamurthy, Thiagarajan

2017-01-01

The development of multidisciplinary integrated Structural Health Management (SHM) tools will enable accurate detection, and prognosis of damaged aircraft under normal and adverse conditions during flight. As part of the digital twin concept, methodologies are developed by using integrated multiphysics models, sensor information and input data from an in-service vehicle to mirror and predict the life of its corresponding physical twin. SHM tools are necessary for both damage diagnostics and prognostics for continued safe operation of damaged aircraft structures. The adverse conditions include loss of control caused by environmental factors, actuator and sensor faults or failures, and structural damage conditions. A major concern in these structures is the growth of undetected damage/cracks due to fatigue and low velocity foreign object impact that can reach a critical size during flight, resulting in loss of control of the aircraft. To avoid unstable, catastrophic propagation of damage during a flight, load levels must be maintained that are below a reduced load-carrying capacity for continued safe operation of an aircraft. Hence, a capability is needed for accurate real-time predictions of damage size and safe load carrying capacity for structures with complex damage configurations. In the present work, a procedure is developed that uses guided wave responses to interrogate damage. As the guided wave interacts with damage, the signal attenuates in some directions and reflects in others. This results in a difference in signal magnitude as well as phase shifts between signal responses for damaged and undamaged structures. Accurate estimation of damage size, location, and orientation is made by evaluating the cumulative signal responses at various pre-selected sensor locations using a genetic algorithm (GA) based optimization procedure. The damage size, location, and orientation is obtained by minimizing the difference between the reference responses and the responses obtained by wave propagation finite element analysis of different representative cracks, geometries, and sizes.

Vibro-Acoustic Modulation Based Damage Identification in a Composite Skin-Stiffener Structure

NASA Technical Reports Server (NTRS)

Ooijevaar, T. H.; Loendersloot, R.; Rogge, M. D.; Akkerman, R.; Tinga, T.

2014-01-01

The vibro-acoustic modulation method is applied to a composite skin-stiffener structure to investigate the possibilities to utilize this method for damage identification in terms of detection, localisation and damage quantification. The research comprises a theoretical part and an experimental part. An impact load is applied to the skin-stiffener structure, resulting in a delamination underneath the stiffener. The structure is interrogated with a low frequency pump excitation and a high frequency carrier excitation. The analysis of the response in a frequency band around the carrier frequency is employed to assess the damage identification capabilities and to gain a better understanding of the modulations occurring and the underlying physical phenomena. Though vibro-acoustic is shown to be a sensitive method for damage identification, the complexity of the damage, combined with a high modal density, complicate the understanding of the relation between the physical phenomena and the modulations occurring. more research is recommended to reveal the physics behind the observations.

Micron-scale coherence in interphase chromatin dynamics

PubMed Central

Zidovska, Alexandra; Weitz, David A.; Mitchison, Timothy J.

2013-01-01

Chromatin structure and dynamics control all aspects of DNA biology yet are poorly understood, especially at large length scales. We developed an approach, displacement correlation spectroscopy based on time-resolved image correlation analysis, to map chromatin dynamics simultaneously across the whole nucleus in cultured human cells. This method revealed that chromatin movement was coherent across large regions (4–5 µm) for several seconds. Regions of coherent motion extended beyond the boundaries of single-chromosome territories, suggesting elastic coupling of motion over length scales much larger than those of genes. These large-scale, coupled motions were ATP dependent and unidirectional for several seconds, perhaps accounting for ATP-dependent directed movement of single genes. Perturbation of major nuclear ATPases such as DNA polymerase, RNA polymerase II, and topoisomerase II eliminated micron-scale coherence, while causing rapid, local movement to increase; i.e., local motions accelerated but became uncoupled from their neighbors. We observe similar trends in chromatin dynamics upon inducing a direct DNA damage; thus we hypothesize that this may be due to DNA damage responses that physically relax chromatin and block long-distance communication of forces. PMID:24019504

Multidisciplinary approach to evaluate flood damage for residential buildings: first results in Northern Italy

NASA Astrophysics Data System (ADS)

Luino, Fabio

2015-04-01

Flooding is the most common natural instability process in Italy. Flood damage are the results of land-use planning policies which, starting chiefly from the late 1950s and early 1960s, did not take into account the geomorphologic-hydraulic characteristics of an area or the its historical data on past flood events. Historically, compared to other areas, riverside property has always been less valuable. Unfortunately, year after year, even areas of high recreational and environmental value were intensely urbanized despite their being exposed to the threat of flooding. As the number of residential dwellings, infrastructure and industrial buildings increased, what was originally a hazard became a risk. For each flood event, the damage depends on the specific land-use of the area and subsequently on the elements at risk in the area involved and its vulnerability, expressed as a percentage of the element that has actually been lost during the event. This is why a comprehensive knowledge of the area it is so important for conducting a detailed survey of an area's structures and infrastructure and to evaluate the degree of vulnerability. This paper presents first results in Italy of the European Project called DAMAGE, the first attempt by the civil protection agencies of several European Union member states to devise a common methodology for the assessment of damage caused by natural or anthropic disasters. The main objective was to create an initial tool for practical and immediate application by civil protection agencies and local governments, to assess damage in a multidimensional perspective that takes into account infrastructure, the economy, the environment and social problems. Within the framework of a broad-based project for the evaluation and collection of reports on damage caused by floods, the CNR-IRPI of Turin and Regione Lombardia have directed attention to the town of Cittiglio (province of Varese), which was struck by severe flash flood in May 2002. One of the aims was to provide public administrations a management tool to help them use damage information. For this purpose a GIS-based model was created that can simulate flood events and evaluate potential direct economic loss due to a catastrophe based on thorough land knowledge coupled with the description of various physical elements of the natural event. The multidisciplinary method can be summarized in the following steps: 1) Event description: definition of flood parameters (flooded area and water level). This definition is possible because of real-time measurements or event simulation through a hydraulic model; 2) Identifying the affected assets in the flooded area; 3) Evaluation of the degree of damage to the exposed elements as a function of event magnitude identified from the measurement of floodwater depths of an event; 4) Attribution of an economic value to exposed assets. Quantification of economic loss by multiplying the economic value of damaged assets and the degree of damage. The methodology can be used to estimate the damage from the impact of floodwater on exposed elements (direct damage) and to quantify the resulting economic loss (tangible damage).

A differential CDM model for fatigue of unidirectional metal matrix composites

NASA Technical Reports Server (NTRS)

Arnold, S. M.; Kruch, S.

1992-01-01

A multiaxial, isothermal, continuum damage mechanics (CDM) model for fatigue of a unidirectional metal matrix composite volume element is presented. The model is phenomenological, stress based, and assumes a single scalar internal damage variable, the evolution of which is anisotropic. The development of the fatigue damage model, (i.e., evolutionary law) is based on the definition of an initially transversely isotropic fatigue limit surface, a static fracture surface, and a normalized stress amplitude function. The anisotropy of these surfaces and function, and therefore the model, is defined through physically meaningful invariants reflecting the local stress and material orientation. This transversely isotropic model is shown, when taken to it's isotropic limit, to directly simplify to a previously developed and validated isotropic fatigue continuum damage model. Results of a nondimensional parametric study illustrate (1) the flexibility of the present formulation in attempting to characterize a class of composite materials, and (2) the capability of the formulation in predicting anticipated qualitative trends in the fatigue behavior of unidirectional metal matrix composites. Also, specific material parameters representing an initial characterization of the composite system SiC/Ti 15-3 and the matrix material (Ti 15-3) are reported.

Guided wave and damage detection in composite laminates using different fiber optic sensors.

PubMed

Li, Fucai; Murayama, Hideaki; Kageyama, Kazuro; Shirai, Takehiro

2009-01-01

Guided wave detection using different fiber optic sensors and their applications in damage detection for composite laminates were systematically investigated and compared in this paper. Two types of fiber optic sensors, namely fiber Bragg gratings (FBG) and Doppler effect-based fiber optic (FOD) sensors, were addressed and guided wave detection systems were constructed for both types. Guided waves generated by a piezoelectric transducer were propagated through a quasi-isotropic carbon fiber reinforced plastic (CFRP) laminate and acquired by these fiber optic sensors. Characteristics of these fiber optic sensors in ultrasonic guided wave detection were systematically compared. Results demonstrated that both the FBG and FOD sensors can be applied in guided wave and damage detection for the CFRP laminates. The signal-to-noise ratio (SNR) of guided wave signal captured by an FOD sensor is relatively high in comparison with that of the FBG sensor because of their different physical principles in ultrasonic detection. Further, the FOD sensor is sensitive to the damage-induced fundamental shear horizontal (SH(0)) guided wave that, however, cannot be detected by using the FBG sensor, because the FOD sensor is omnidirectional in ultrasound detection and, in contrast, the FBG sensor is severely direction dependent.

Rapid assessment of disaster damage using social media activity

PubMed Central

Kryvasheyeu, Yury; Chen, Haohui; Obradovich, Nick; Moro, Esteban; Van Hentenryck, Pascal; Fowler, James; Cebrian, Manuel

2016-01-01

Could social media data aid in disaster response and damage assessment? Countries face both an increasing frequency and an increasing intensity of natural disasters resulting from climate change. During such events, citizens turn to social media platforms for disaster-related communication and information. Social media improves situational awareness, facilitates dissemination of emergency information, enables early warning systems, and helps coordinate relief efforts. In addition, the spatiotemporal distribution of disaster-related messages helps with the real-time monitoring and assessment of the disaster itself. We present a multiscale analysis of Twitter activity before, during, and after Hurricane Sandy. We examine the online response of 50 metropolitan areas of the United States and find a strong relationship between proximity to Sandy’s path and hurricane-related social media activity. We show that real and perceived threats, together with physical disaster effects, are directly observable through the intensity and composition of Twitter’s message stream. We demonstrate that per-capita Twitter activity strongly correlates with the per-capita economic damage inflicted by the hurricane. We verify our findings for a wide range of disasters and suggest that massive online social networks can be used for rapid assessment of damage caused by a large-scale disaster. PMID:27034978

Rapid assessment of disaster damage using social media activity.

PubMed

Kryvasheyeu, Yury; Chen, Haohui; Obradovich, Nick; Moro, Esteban; Van Hentenryck, Pascal; Fowler, James; Cebrian, Manuel

2016-03-01

Could social media data aid in disaster response and damage assessment? Countries face both an increasing frequency and an increasing intensity of natural disasters resulting from climate change. During such events, citizens turn to social media platforms for disaster-related communication and information. Social media improves situational awareness, facilitates dissemination of emergency information, enables early warning systems, and helps coordinate relief efforts. In addition, the spatiotemporal distribution of disaster-related messages helps with the real-time monitoring and assessment of the disaster itself. We present a multiscale analysis of Twitter activity before, during, and after Hurricane Sandy. We examine the online response of 50 metropolitan areas of the United States and find a strong relationship between proximity to Sandy's path and hurricane-related social media activity. We show that real and perceived threats, together with physical disaster effects, are directly observable through the intensity and composition of Twitter's message stream. We demonstrate that per-capita Twitter activity strongly correlates with the per-capita economic damage inflicted by the hurricane. We verify our findings for a wide range of disasters and suggest that massive online social networks can be used for rapid assessment of damage caused by a large-scale disaster.

Space Radiation Induced Cytogenetic Damage in the Blood Lymphocytes of Astronauts

NASA Technical Reports Server (NTRS)

George, K.; Cucinotta, F. A.

2008-01-01

Cytogenetic analysis of astronauts blood lymphocytes provides a direct in vivo measurement of space radiation damage, which takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. We present our latest analyses of chromosome damage in astronauts blood lymphocytes assessed by fluorescence in situ hybridization (FISH) chromosome painting and collected at various times beginning directly after return from space to several years after flight. Dose was derived from frequencies of chromosome exchanges using preflight calibration curves, and the Relative Biological Effect (RBE) was estimated by comparison with individually measured physically absorbed doses. Values for average RBE were compared to the average quality factor (Q), from direct measurements of the lineal energy spectra using a tissue-equivalent proportional counter (TEPC) and radiation transport codes. Results prove that cytogenetic biodosimetry analyses on blood collected within a week or two of return from space provides a reliable estimate of equivalent radiation dose and risk after protracted exposure to space radiation of a few months or more. However, data collected several months or years after flight suggests that the yield of chromosome translocations may decline with time after the mission, indicating that retrospective doses may be more difficult to estimate. In addition, limited data on multiple flights show a lack of correlation between time in space and translocation yields. Data from one crewmember, who has participated in two separate long-duration space missions and has been followed up for over 10 years, provide limited information on the effect of repeat flights and show a possible adaptive response to space radiation exposure.

Damage and Loss Estimation for Natural Gas Networks: The Case of Istanbul

NASA Astrophysics Data System (ADS)

Çaktı, Eser; Hancılar, Ufuk; Şeşetyan, Karin; Bıyıkoǧlu, Hikmet; Şafak, Erdal

2017-04-01

Natural gas networks are one of the major lifeline systems to support human, urban and industrial activities. The continuity of gas supply is critical for almost all functions of modern life. Under natural phenomena such as earthquakes and landslides the damages to the system elements may lead to explosions and fires compromising human life and damaging physical environment. Furthermore, the disruption in the gas supply puts human activities at risk and also results in economical losses. This study is concerned with the performance of one of the largest natural gas distribution systems in the world. Physical damages to Istanbul's natural gas network are estimated under the most recent probabilistic earthquake hazard models available, as well as under simulated ground motions from physics based models. Several vulnerability functions are used in modelling damages to system elements. A first-order assessment of monetary losses to Istanbul's natural gas distribution network is also attempted.

Approach for Assessing Direct Flood Damages

NASA Astrophysics Data System (ADS)

Gaňová, Lenka; Zeleňáková, Martina; Słyś, Daniel; Purcz, Pavol

2014-11-01

This article presents a methodological approach to flood direct tangible damage - damage to assets and direct intangible damage - environmental damage and loss of life assessment. The assessment of flood risk is an essential part of the risk management approach, which is the conceptual basis for the EU directive 2007/60/ES on the assessment and management of flood risk. The purpose of this directive is to establish a framework for the assessment and management of flood risk, aiming at the reduction of the adverse consequences for human health, the environment, cultural heritage and economic activity associated with flood in the community. Overall, an accurate estimation of negative effects on assets, environment and people is important in order to be able to determine the economy, environmental and social flood risk level in a system and the effects of risk mitigation measures.

School role in health education in Italy.

PubMed

Costanzo, Sergio

2011-10-01

Intellectual and knowledge values on one side, and vital and physical values on the other, need to be balanced. A harmonious coexistence of these values requires synergy among the bodies that contribute to children education to avoid that the heath education activities cause overlapping, misunderstanding and conflicts between the two models that define children lifestyles: schools and families. Educational bodies understand that health education is key to enable people manage their bio-psychic, emotional, moral and mental resources. Lack of this ability means damage to the child and consequently a failure of the school and the society itself. In the latest decades, schools have been working in this direction, and they have redefined the national curricula integrating health education with specific references to food education and physical activity.

Genomic biomarkers and clinical outcomes of physical activity.

PubMed

Izzotti, Alberto

2011-07-01

Clinical and experimental studies in humans provide evidence that moderate physical activity significantly decreases artery oxidative damage to nuclear DNA, DNA-adducts related to age and dyslipedemia, and mitochondrial DNA damage. Maintenance of adequate mitochondrial function is crucial for preventing lipid accumulation and peroxidation occurring in atherosclerosis. Studies performed on human muscle biopsies analyzing gene expression in living humans reveal that physically active subjects improve the expression of genes involved in mitochondrial function and of related microRNAs. The attenuation of oxidative damage to nuclear and mitochondrial DNA by physical activity resulted in beneficial effects due to polymorphisms of glutathione S-transferases genes. Subjects bearing null GSTM1/T1 polymorphisms have poor life expectancy in the case of being sedentary, which was increased 2.6-fold in case they performed physical activity. These findings indicate that the preventive effect of physical activity undergoes interindividual variation affected by genetic polymorphisms. © 2011 New York Academy of Sciences.

Effects of the earthquake of March 27, 1964, at Anchorage, Alaska: Chapter A in The Alaska earthquake, March 27, 1964: effects on communities

USGS Publications Warehouse

Hansen, Wallace R.

1965-01-01

Anchorage, Alaska’s largest city, is about 80 miles west-northwest of the epicenter of the March 27 earthquake. Because of its size, Anchorage bore the brunt of property damage from the quake; it sustained greater losses than all the rest of Alaska combined. Damage was caused by direct seismic vibration, by ground cracks, and by landslides. Direct seismic vibration affected chiefly multistory buildings and buildings having large floor areas, probably because of the long period and large amplitude of the seismic waves reaching Anchorage. Most small buildings were spared. Ground cracks caused capricious damage throughout the Anchorage Lowland. Cracking was mast prevalent near the heads or within landslides but was also widespread elsewhere. Landslides themselves caused the most devastating damage. Triggering of landslides by the earthquake was related to the physical-engineering properties of the Bootlegger Cove Clay, a glacial estuarine-marine deposit that underlies much of the Anchorage area. The Bootlegger Cove Clay contains zones of low shear strength, high water content, and high sensitivity that failed under the vibratory stress of the earthquake. Shear strength in sensitive zones ranged from less than 0.2 tsf to about 0.5 tsf; sensitivity ranged from about 10 to more than 40. Sensitive zones generally are centered about 10 to 20 feet above sea level, between zones of stiff insensitive clay. Many physical tests by the U.S. Army Corps of Engineers were directed toward analyzing the causes of failure in the Bootlegger Cove Clay and finding possible remedies. Strengths and sensitivities were measured directly in the field by means of vane shear apparatus. A4tterberg limits, natural water contents, triaxial shear, sensitivity, dynamic modulus, consolidation strength, and other properties were measured in the laboratory. Pulsating-load tests simulated earthquake loading. Most of the destructive landslides in the Anchorage area moved primarily by translation rather than by rotation. Thus, all the highly damaging slides were of a single structural dynamic family despite wide variations in size, appearance, and complexity. They slid on nearly horizontal slip surfaces after loss of strength in the Bootlegger Core Clay. Same failures are attributed to spontaneous liquefaction of sand layers. All translatory slides surmounted flat-topped bluffs bounded marginally by steep slopes facing lower ground. Destructive translatory slides occurred in the downtown area (Fourth Avenue slide and L Street slide), at Government Hill, and at Turnagain Heights. Less destructive slides occurred in many other places-mostly uninhabited or undeveloped areas. In most translatory slides, damage was greatest in graben areas at the head and in pressure-ridge areas at the toe. Many buildings inside the perimeters of slide blocks were little damaged despite horizontal translations of several feet. The large Turnagain Heights slide, however, was characterized by a complete disintegration and drastic lowering of the prequake land surface. Extensive damage back from the slide, moreover, was caused by countless tension cracks. An approximation of the depth of failure in the Bootlegger Cove Clay in the various slides may be obtained by using a geometric relationship herein called the "graben rule." Because the cross-sectional area of the graben at the head of the slide approximated the cross-sectional area of the space voided behind the slide block as the block moved outward, the depth of failure was equal to the area of the graben divided by the lateral displacement. This approximation supplements and accords with test data obtained from borings. The graben rule should apply to any translatory slide in which flowage of material from the zone of failure has not been excessive. Geologic evidence indicates that landslides similar to those triggered by the March 27 earthquake have occurred in the Anchorage area at various times in the past.

Physical exercise and oxidative stress in muscular dystrophies: is there a good balance?

PubMed

Chico, L; Ricci, G; Cosci O Di Coscio, M; Simoncini, C; Siciliano, G

2017-07-01

The effect of oxidative stress on muscle damage inducted by physical exercise is widely debated. It is generally agreed that endurance and intense exercise can increase oxidative stress and generate changes in antioxidant power inducing muscle damage; however, regular and moderate exercise can be beneficial for the health improving the antioxidant defense mechanisms in the majority of cases. Growing evidences suggest that an increased oxidative/nitrosative stress is involved in the pathogenesis of several muscular dystrophies (MDs). Notably, physical training has been considered useful for patients with these disorders. This review will focus on the involvement of oxidative stress in MDs and on the possible effects of physical activities to decrease oxidative damage and improve motor functions in MDs patients.

An integrated physiology model to study regional lung damage effects and the physiologic response

PubMed Central

2014-01-01

Background This work expands upon a previously developed exercise dynamic physiology model (DPM) with the addition of an anatomic pulmonary system in order to quantify the impact of lung damage on oxygen transport and physical performance decrement. Methods A pulmonary model is derived with an anatomic structure based on morphometric measurements, accounting for heterogeneous ventilation and perfusion observed experimentally. The model is incorporated into an existing exercise physiology model; the combined system is validated using human exercise data. Pulmonary damage from blast, blunt trauma, and chemical injury is quantified in the model based on lung fluid infiltration (edema) which reduces oxygen delivery to the blood. The pulmonary damage component is derived and calibrated based on published animal experiments; scaling laws are used to predict the human response to lung injury in terms of physical performance decrement. Results The augmented dynamic physiology model (DPM) accurately predicted the human response to hypoxia, altitude, and exercise observed experimentally. The pulmonary damage parameters (shunt and diffusing capacity reduction) were fit to experimental animal data obtained in blast, blunt trauma, and chemical damage studies which link lung damage to lung weight change; the model is able to predict the reduced oxygen delivery in damage conditions. The model accurately estimates physical performance reduction with pulmonary damage. Conclusions We have developed a physiologically-based mathematical model to predict performance decrement endpoints in the presence of thoracic damage; simulations can be extended to estimate human performance and escape in extreme situations. PMID:25044032

Differential continuum damage mechanics models for creep and fatigue of unidirectional metal matrix composites

NASA Technical Reports Server (NTRS)

Arnold, S. M.; Kruch, S.

1991-01-01

Three multiaxial isothermal continuum damage mechanics models for creep, fatigue, and creep/fatigue interaction of a unidirectional metal matrix composite volume element are presented, only one of which will be discussed in depth. Each model is phenomenological and stress based, with varying degrees of complexity to accurately predict the initiation and propagation of intergranular and transgranular defects over a wide range of loading conditions. The development of these models is founded on the definition of an initially transversely isotropic fatigue limit surface, static fracture surface, normalized stress amplitude function and isochronous creep damage failure surface, from which both fatigue and creep damage evolutionary laws can be obtained. The anisotropy of each model is defined through physically meaningful invariants reflecting the local stress and material orientation. All three transversely isotropic models have been shown, when taken to their isotropic limit, to directly simplify to previously developed and validated creep and fatigue continuum damage theories. Results of a nondimensional parametric study illustrate (1) the flexibility of the present formulation when attempting to characterize a large class of composite materials, and (2) its ability to predict anticipated qualitative trends in the fatigue behavior of unidirectional metal matrix composites. Additionally, the potential for the inclusion of various micromechanical effects (e.g., fiber/matrix bond strength, fiber volume fraction, etc.), into the phenomenological anisotropic parameters is noted, as well as a detailed discussion regarding the necessary exploratory and characterization experiments needed to utilize the featured damage theories.

Physics-based Modeling of Material Behavior and Damage Initiation in Nanoengineered Composites

NASA Astrophysics Data System (ADS)

Subramanian, Nithya

Materials with unprecedented properties are necessary to make dramatic changes in current and future aerospace platforms. Hybrid materials and composites are increasingly being used in aircraft and spacecraft frames; however, future platforms will require an optimal design of novel materials that enable operation in a variety of environments and produce known/predicted damage mechanisms. Nanocomposites and nanoengineered composites with CNTs have the potential to make significant improvements in strength, stiffness, fracture toughness, flame retardancy and resistance to corrosion. Therefore, these materials have generated tremendous scientific and technical interest over the past decade and various architectures are being explored for applications to light-weight airframe structures. However, the success of such materials with significantly improved performance metrics requires careful control of the parameters during synthesis and processing. Their implementation is also limited due to the lack of complete understanding of the effects the nanoparticles impart to the bulk properties of composites. It is common for computational methods to be applied to explain phenomena measured or observed experimentally. Frequently, a given phenomenon or material property is only considered to be fully understood when the associated physics has been identified through accompanying calculations or simulations. The computationally and experimentally integrated research presented in this dissertation provides improved understanding of the mechanical behavior and response including damage and failure in CNT nanocomposites, enhancing confidence in their applications. The computations at the atomistic level helps to understand the underlying mechanochemistry and allow a systematic investigation of the complex CNT architectures and the material performance across a wide range of parameters. Simulation of the bond breakage phenomena and development of the interface to continuum scale damage captures the effects of applied loading and damage precursor and provides insight into the safety of nanoengineered composites under service loads. The validated modeling methodology is expected to be a step in the direction of computationally-assisted design and certification of novel materials, thus liberating the pace of their implementation in future applications.

Mechanisms of CNS invasion and damage by parasites.

PubMed

Kristensson, Krister; Masocha, Willias; Bentivoglio, Marina

2013-01-01

Invasion of the central nervous system (CNS) is a most devastating complication of a parasitic infection. Several physical and immunological barriers provide obstacles to such an invasion. In this broad overview focus is given to the physical barriers to neuroinvasion of parasites provided at the portal of entry of the parasites, i.e., the skin and epithelial cells of the gastrointestinal tract, and between the blood and the brain parenchyma, i.e., the blood-brain barrier (BBB). A description is given on how human pathogenic parasites can reach the CNS via the bloodstream either as free-living or extracellular parasites, by embolization of eggs, or within red or white blood cells when adapted to intracellular life. Molecular mechanisms are discussed by which parasites can interact with or pass across the BBB. The possible targeting of the circumventricular organs by parasites, as well as the parasites' direct entry to the brain from the nasal cavity through the olfactory nerve pathway, is also highlighted. Finally, examples are given which illustrate different mechanisms by which parasites can cause dysfunction or damage in the CNS related to toxic effects of parasite-derived molecules or to immune responses to the infection. Copyright © 2013 Elsevier B.V. All rights reserved.

Incorporation of Damage and Failure into an Orthotropic Elasto-Plastic Three-Dimensional Model with Tabulated Input Suitable for Use in Composite Impact Problems

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Carney, Kelly S.; Dubois, Paul; Hoffarth, Canio; Khaled, Bilal; Rajan, Subramaniam; Blankenhorn, Gunther

2016-01-01

A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in the composite impact models currently available in LS-DYNA(Registered Trademark) is under development. In particular, the material model, which is being implemented as MAT 213 into a tailored version of LS-DYNA being jointly developed by the FAA and NASA, incorporates both plasticity and damage within the material model, utilizes experimentally based tabulated input to define the evolution of plasticity and damage as opposed to specifying discrete input parameters (such as modulus and strength), and is able to analyze the response of composites composed with a variety of fiber architectures. The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. The capability to account for the rate and temperature dependent deformation response of composites has also been incorporated into the material model. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a diagonal damage tensor is defined to account for the directionally dependent variation of damage. However, in composites it has been found that loading in one direction can lead to damage in multiple coordinate directions. To account for this phenomena, the terms in the damage matrix are semi-coupled such that the damage in a particular coordinate direction is a function of the stresses and plastic strains in all of the coordinate directions. The onset of material failure, and thus element deletion, is being developed to be a function of the stresses and plastic strains in the various coordinate directions. Systematic procedures are being developed to generate the required input parameters based on the results of experimental tests.

Identification of the formation phases of filamentary damage induced by nanosecond laser pulses in bulk fused silica

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

Shen, Chao; Xu, Zhongjie; Chambonneau, Maxime, E-mail: chambonneau@lp3.univ-mrs.fr, E-mail: jiangtian198611@163.com

2015-09-14

Employing a pump-probe polarization-based two-frame shadowgraphy setup, the formation of filamentary damage induced in bulk fused silica by a nanosecond pulse at 1064 nm is investigated with a picosecond probe. Three different phases are exhibited in the damage experiments. The first phase is the formation of a micrometric plasma channel along the laser direction during the beginning of the pulse likely caused by multi-photon ionization. This channel exhibits growth during ∼400 ps, and the newly grown plasma is discrete. Then, during the end of the pulse, this channel evolves into a tadpole-like morphology showing an elliptical head upstream the laser fluxmore » followed by a thin tail. This observed asymmetry is attributed to shielding effects caused by both the plasma and hot modified silica. Once the damage shows its almost final morphology, a last phase consists in the launch of a pressure wave enlarging it after the laser pulse. The physical mechanisms that might be involved in the formation of plasma channels are discussed. The experimental data are first confronted to the moving breakdown model which overestimates the filamentary damage length. Finally, taking into account the temporal shape of the laser pulses, the coupling between Kerr-induced self-focusing and stimulated Brillouin scattering is discussed to interpret the observations.« less

Numerical analysis of installation damage of a pre-damaged geogrid with rectangular apertures

NASA Astrophysics Data System (ADS)

Dong, Yan-li; Guo, Hui-juan; Han, Jie; Zhang, Jun

2018-06-01

The geogrid can be damaged in the process or during construction if sufficient care is not exercised. In this study, the numerical software-FLAC was adopted to investigate the responses of pre-damaged geogrids with rectangular apertures when subjected to a uniaxial tensile load at different directions relative to the orientations of ribs in air. To simulate the combined loss of ribs and junction strength, specimens were pre-damaged by reducing certain amount of stiffness of the geogrid ribs. The geogrid ribs were modeled using beam elements jointed rigidly at nodes and subjected to tension in one direction. The numerical study demonstrated that the pre-damaged geogrid with rectangular apertures had similar responses when it was subjected to tension at the loading directions. The pre-damaged geogrids under 30° tension are the most sensitivity to the damage. With the increase of the degree of damage, the tensile strengths decreased relative quickly. An increase of the degree of installation damage of ribs decreased the tensile strength/stiffness of the geogrid with rectangular apertures. A higher reduction factor RFID due to installation damage is suggested when the geogrid is subjected to 30° tension relative to the orientation of ribs.

Economic impacts of the SAFRR tsunami scenario in California: Chapter H in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Wein, Anne; Rose, Adam; Sue Wing, Ian; Wei, Dan

2013-01-01

This study evaluates the hypothetical economic impacts of the SAFRR (Science Application for Risk Reduction) tsunami scenario to the California economy. The SAFRR scenario simulates a tsunami generated by a hypothetical magnitude 9.1 earthquake that occurs offshore of the Alaska Peninsula (Kirby and others, 2013). Economic impacts are measured by the estimated reduction in California’s gross domestic product (GDP), the standard economic measure of the total value of goods and services produced. Economic impacts are derived from the physical damages from the tsunami as described by Porter and others (2013). The principal physical damages that result in disruption of the California economy are (1) about $100 million in damages to the twin Ports of Los Angeles (POLA) and Long Beach (POLB), (2) about $700 million in damages to marinas, and (3) about $2.5 billion in damages to buildings and contents (properties) in the tsunami inundation zone on the California coast. The study of economic impacts does not include the impacts from damages to roads, bridges, railroads, and agricultural production or fires in fuel storage facilities because these damages will be minimal with respect to the California economy. The economic impacts of damage to other California ports are not included in this study because detailed evaluation of the physical damage to these ports was not available in time for this report. The analysis of economic impacts is accomplished in several steps. First, estimates are made for the direct economic impacts that result in immediate business interruption losses in individual sectors of the economy due to physical damage to facilities or to disruption of the flow of production units (commodities necessary for production). Second, the total economic impacts (consisting of both direct and indirect effects) are measured by including the general equilibrium (essentially quantity and price multiplier effects) of lost production in other sectors by ripple effects upstream and downstream along the supply chain. An appropriate measure of the economic impacts on the California economy for the SAFRR tsunami scenario is the reduction in GDP. The economic impacts are first calculated without resilience, the ability of the economy to adjust to disruptions in ways that mute potential negative impacts. There are many types of resilience, including using existing inventories of materials, using unused capacity, conserving inputs, substituting for disrupted supplies, recapturing production after the disruption is restored, and many others. A method for estimating resilience, identified in the port system and sectors affected by property damages, is applied to indicate potential reductions of direct and total economic impacts. In this SAFRR tsunami scenario analysis of economic impacts to California, we implement established techniques used to model the economic impacts for two previous U.S. Geological Survey (USGS) scenarios: the southern California Shakeout earthquake (Rose and others, 2011) and the California ARkStorm severe winter storm (Sue Wing and others, written commun., 2013). For the SAFRR tsunami scenario, we reviewed the relevant studies that assess economic impacts from previous tsunami events affecting California and elsewhere and estimate the economic impacts of potential tsunami and other threats to POLA and POLB. To our knowledge, assessment of impacts to the California economy from distant source tsunamis does not exist. Previous tsunamis, including those from the 1960 Chile earthquake, the 1964 Alaska earthquake, the 2008 Chile earthquake and the 2011 Japan earthquake, had only relatively minor or very localized severe damage (such as that in Crescent City in 1964), and no studies of the economic impacts were completed. A rare study of the economic impacts of a tsunami event has recently been produced for the Tohoku earthquake and tsunami (Kajitani and others, 2013). Quarterly declines in Japan’s GDP are observed to peak at ‒1.63 percent in the second quarter after the event and stagnate for the rest of the year. The majority of the economic impacts are attributed to the tsunami rather than the earthquake. The hardest hit sectors are identified as agriculture, fisheries, manufacturing, retail, and tourism. Other relevant studies have focused on the economic impacts of threats that close POLA and POLB. We find one analysis of a potential tsunami scenario affecting the California economy through disruption of port operations. Borrero and others (2005) estimated economic impacts to the southern California economy of $7 to $40 billion from a locally generated tsunami that closes POLA and POLB for as much as 1 year. There have also been several studies of the economic impacts of non-tsunami events affecting POLA and POLB. Analyses of an 11-day labor lockout produced a range of estimated national impacts of as much as $1.94 billion/day (Park and others 2008, Martin Associates 2001). Examination of a potential terrorist attack that closes the San Pedro port for 1 month yielded a $29 billion impact to the California economy (Park, 2008). These studies have reinforced the importance of recognizing economic resilience in economic impact analyses. Hall (2004) criticized the upper-end estimate of national economic impacts from the labor lockout based on model shortcomings that neglected short-run substitution behavior and fixed the long-run economic behaviors. Following the 2011 Japanese tsunami, resilience was observed in the forms of rapid recovery of manufacturing sectors, energy conservation, and insurance (Kajitani and others, 2013).

Crack initiation modeling of a directionally-solidified nickel-base superalloy

NASA Astrophysics Data System (ADS)

Gordon, Ali Page

Combustion gas turbine components designed for application in electric power generation equipment are subject to periodic replacement as a result of cracking, damage, and mechanical property degeneration that render them unsafe for continued operation. In view of the significant costs associated with inspecting, servicing, and replacing damaged components, there has been much interest in developing models that not only predict service life, but also estimate the evolved microstructural state of the material. This thesis explains manifestations of microstructural damage mechanisms that facilitate fatigue crack nucleation in a newly-developed directionally-solidified (DS) Ni-base superalloy components exposed to elevated temperatures and high stresses. In this study, models were developed and validated for damage and life prediction using DS GTD-111 as the subject material. This material, proprietary to General Electric Energy, has a chemical composition and grain structure designed to withstand creep damage occurring in the first and second stage blades of gas-powered turbines. The service conditions in these components, which generally exceed 600°C, facilitate the onset of one or more damage mechanisms related to fatigue, creep, or environment. The study was divided into an empirical phase, which consisted of experimentally simulating service conditions in fatigue specimens, and a modeling phase, which entailed numerically simulating the stress-strain response of the material. Experiments have been carried out to simulate a variety of thermal, mechanical, and environmental operating conditions endured by longitudinally (L) and transversely (T) oriented DS GTD-111. Both in-phase and out-of-phase thermo-mechanical fatigue tests were conducted. In some cases, tests in extreme environments/temperatures were needed to isolate one or at most two of the mechanisms causing damage. Microstructural examinations were carried out via SEM and optical microscopy. A continuum crystal plasticity model was used to simulate the material behavior in the L and T orientations. The constitutive model was implemented in ABAQUS and a parameter estimation scheme was developed to obtain the material constants. A physically-based model was developed for correlating crack initiation life based on the experimental life data and predictions are made using the crack initiation model. Assuming a unique relationship between the damage fraction and cycle fraction with respect to cycles to crack initiation for each damage mode, the total crack initiation life has been represented in terms of the individual damage components (fatigue, creep-fatigue, creep, and oxidation-fatigue) observed at the end state of crack initiation.

Sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation will increase in lipopolysaccharide-induced inflammation in vitro model.

PubMed

Zuo, Wen-Qi; Hu, Yu-Juan; Yang, Yang; Zhao, Xue-Yan; Zhang, Yuan-Yuan; Kong, Wen; Kong, Wei-Jia

2015-05-29

With the increasing popularity of mobile phones, the potential hazards of radiofrequency electromagnetic radiation (RF-EMR) on the auditory system remain unclear. Apart from RF-EMR, humans are also exposed to various physical and chemical factors. We established a lipopolysaccharide (LPS)-induced inflammation in vitro model to investigate whether the possible sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation (at specific absorption rates: 2, 4 W/kg) will increase. Spiral ganglion neurons (SGN) were obtained from neonatal (1- to 3-day-old) Sprague Dawley® (SD) rats. After the SGN were treated with different concentrations (0, 20, 40, 50, 100, 200, and 400 μg/ml) of LPS, the Cell Counting Kit-8 (CCK-8) and alkaline comet assay were used to quantify cellular activity and DNA damage, respectively. The SGN were treated with the moderate LPS concentrations before RF-EMR exposure. After 24 h intermittent exposure at an absorption rate of 2 and 4 W/kg, DNA damage was examined by alkaline comet assay, ultrastructure changes were detected by transmission electron microscopy, and expression of the autophagy markers LC3-II and Beclin1 were examined by immunofluorescence and confocal laser scanning microscopy. Reactive oxygen species (ROS) production was quantified by the dichlorofluorescin-diacetate assay. LPS (100 μg/ml) induced DNA damage and suppressed cellular activity (P < 0.05). LPS (40 μg/ml) did not exhibit cellular activity changes or DNA damage (P > 0.05); therefore, 40 μg/ml was used to pretreat the concentration before exposure to RF-EMR. RF-EMR could not directly induce DNA damage. However, the 4 W/kg combined with LPS (40 μg/ml) group showed mitochondria vacuoles, karyopyknosis, presence of lysosomes and autophagosome, and increasing expression of LC3-II and Beclin1. The ROS values significantly increased in the 4 W/kg exposure, 4 W/kg combined with LPS (40 μg/ml) exposure, and H2O2 groups (P < 0.05, 0.01). Short-term exposure to radiofrequency electromagnetic radiation could not directly induce DNA damage in normal spiral ganglion neurons, but it could cause the changes of cellular ultrastructure at special SAR 4.0 W/kg when cells are in fragile or micro-damaged condition. It seems that the sensitivity of SGN to damage caused by mobile phone electromagnetic radiation will increase in a lipopolysaccharide-induced inflammation in vitro model.

DOE/NV/25946--1586 Geologic Assessment of the Damage Zone from the Second Test at Source Physics Experiment-Nevada (SPE-N)

NASA Astrophysics Data System (ADS)

Townsend, M.; Huckins-Gang, H.; Prothro, L.; Reed, D.

2012-12-01

The National Center for Nuclear Security, established by the U.S. Department of Energy, National Nuclear Security Administration, is conducting a series of explosive tests at the Nevada National Security Site that are designed to increase the understanding of certain basic physical phenomena associated with underground explosions. These tests will aid in developing technologies that might be used to detect underground nuclear explosions in support of verification activities for the Comprehensive Nuclear-Test-Ban Treaty. The initial project is a series of explosive tests, known collectively as the Source Physics Experiment-Nevada (SPE-N), being conducted in granitic rocks. The SPE N test series is designed to study the generation and propagation of seismic waves. The results will help advance the seismic monitoring capability of the United States by improving the predictive capability of physics-based modeling of explosive phenomena. The first SPE N (SPE N1) test was conducted in May 2011, using 0.1 ton of explosives at the depth of 54.9 m in the U 15n source hole. SPE N2 was conducted in October 2011, using 1.0 ton of explosives at the depth of 45.7 m in the same source hole. The SPE N3 test was conducted in the same source hole in July 2012, using the same amount and type of explosive as for SPE N2, and at the same depth as SPE N2, within the damage zone created by the SPE N2 explosion to investigate damage effects on seismic wave propagation. Following the SPE N2 shot and prior to the SPE N3 shot, the core hole U-15n#10 was drilled at an angle from the surface to intercept the SPE N2 shot point location to obtain information necessary to characterize the damage zone. The desire was to determine the position of the damage zone near the shot point, at least on the northeast, where the core hole penetrated it, and obtain information on the properties of the damaged medium. Geologic characterization of the post-SPE N2 core hole included geophysical logging, a directional survey, and geologic description of the core to document visual evidence of damage. Selected core samples were provided to Sandia National Laboratories for measurement of physical and mechanical properties. A video was also run in the source hole after it was cleaned out. A significant natural fault zone was encountered in the angle core hole between 5.7 and 7.5 m from the shot point. However, several of the fractures observed in the core hole are interpreted as having been caused by the explosion. The fractures are characterized by a "fresh," mechanically broken look, with uncoated and very irregular surfaces. They tend to terminate against natural fractures and have orientations that differ from the previously defined natural fracture sets; they are common starting at about 5.4 m from the shot point. Within about 3.3 m of the shot point to the end of the recovered core at 1.6 m from the shot point, some of the core samples are softer and lighter in color, but do not appear to be weathered. It is thought this could be indicative of the presence of distributed microfracturing. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

Interactions between spacecraft motions and the atmospheric cloud physics laboratory experiments

NASA Technical Reports Server (NTRS)

Anderson, B. J.

1981-01-01

In evaluating the effects of spacecraft motions on atmospheric cloud physics laboratory (ACPL) experimentation, the motions of concern are those which will result in the movement of the fluid or cloud particles within the experiment chambers. Of the various vehicle motions and residual forces which can and will occur, three types appear most likely to damage the experimental results: non-steady rotations through a large angle, long-duration accelerations in a constant direction, and vibrations. During the ACPL ice crystal growth experiments, the crystals are suspended near the end of a long fiber (20 cm long by 200 micron diameter) of glass or similar material. Small vibrations of the supported end of the fiber could cause extensive motions of the ice crystal, if care is not taken to avoid this problem.

Visual attention to and perception of undamaged and damaged versions of natural and colored female hair.

PubMed

Fink, Bernhard; Neuser, Frauke; Deloux, Gwenelle; Röder, Susanne; Matts, Paul J

2013-03-01

Female hair color is thought to influence physical attractiveness, and although there is some evidence for this assertion, research has yet not addressed the question if and how physical damaging affects the perception of female hair color. Here we investigate whether people are sensitive (in terms of visual attention and age, health and attractiveness perception) to subtle differences in hair images of natural and colored hair before and after physical damaging. We tracked the eye-gaze of 50 men and 50 women aged 31-50 years whilst they viewed randomized pairs of images of 20 natural and 20 colored hair tresses, each pair displaying the same tress before and after controlled cuticle damage. The hair images were then rated for perceived health, attractiveness, and age. Undamaged versions of natural and colored hair were perceived as significantly younger, healthier, and more attractive than corresponding damaged versions. Visual attention to images of undamaged colored hair was significantly higher compared with their damaged counterparts, while in natural hair, the opposite pattern was found. We argue that the divergence in visual attention to undamaged colored female hair and damaged natural female hair and associated ratings is due to differences in social perception and discuss the source of apparent visual difference between undamaged and damaged hair. © 2013 Wiley Periodicals, Inc.

All-Dielectric Photonic-Assisted Radio Front-End Technology

NASA Astrophysics Data System (ADS)

Ayazi, Hossein Ali

The threats to civil society posed by high-power electromagnetic weapons are viewed as a grim but real possibility in the world after 11 September 2001. These weapons produce a power surge capable of destroying or damaging sensitive circuitry in electronic systems. Unfortunately, the trend towards circuits with smaller sizes and voltages renders modern electronics highly susceptible to such damage. Radiofrequency communication systems are particularly vulnerable, because the antenna provides a direct port of entry for electromagnetic radiation. In this work, we present a novel type of radiofrequency receiver front end featuring a complete absence of electronic circuitry and metal interconnects, the traditional 'soft spots' of a conventional radiofrequency receiver. The device exploits a dielectric resonator antenna to capture and deliver the radiofrequency signal onto a whispering-gallery mode electro-optic field sensor. The dielectric approach has an added benefit in that it reduces the physical size of the front end, an important benefit in mobile applications.

Predictive modeling of composite material degradation using piezoelectric wafer sensors electromechanical impedance spectroscopy

NASA Astrophysics Data System (ADS)

Gresil, Matthieu; Yu, Lingyu; Sutton, Mike; Guo, Siming; Pollock, Patrick

2012-04-01

The advancement of composite materials in aircraft structures has led to on increased need for effective structural health monitoring (SHM) technologies that are able to detect and assess damage present in composites structures. The work presented in this paper is interested in understanding using self-sensing piezoelectric wafer active sensors (PWAS) to conduct electromechanical impedance spectroscopy (EMIS) in glass fiber reinforced plastic (GFRP) to perform structures health monitoring. PWAS are bonded to the composite material and the EMIS method is used to analyze the changes in the structural resonance and anti-resonance. As the damage progresses in the specimen, the impedance spectrum will change. In addition, multi-physics based finite element method (MP-FEM) is used to model the electromechanical behavior of a free PWAS and its interaction with the host structure on which it is bonded. The MPFEM permits the input and the output variables to be expressed directly in electric terms while the two way electromechanical conversion is done internally in the MP_FEM formulation. To reach the goal of using the EMIS approach to detect damage, several damages models are generated on laminated GFRP structures. The effects of the modeling are carefully studied through experimental validation. A good match has been observed for low and very high frequencies.

Direct evaluation of influence of electron damage on the subcell performance in triple-junction solar cells using photoluminescence decays.

PubMed

Tex, David M; Nakamura, Tetsuya; Imaizumi, Mitsuru; Ohshima, Takeshi; Kanemitsu, Yoshihiko

2017-05-16

Tandem solar cells are suited for space applications due to their high performance, but also have to be designed in such a way to minimize influence of degradation by the high energy particle flux in space. The analysis of the subcell performance is crucial to understand the device physics and achieve optimized designs of tandem solar cells. Here, the radiation-induced damage of inverted grown InGaP/GaAs/InGaAs triple-junction solar cells for various electron fluences are characterized using conventional current-voltage (I-V) measurements and time-resolved photoluminescence (PL). The conversion efficiencies of the entire device before and after damage are measured with I-V curves and compared with the efficiencies predicted from the time-resolved method. Using the time-resolved data the change in the carrier dynamics in the subcells can be discussed. Our optical method allows to predict the absolute electrical conversion efficiency of the device with an accuracy of better than 5%. While both InGaP and GaAs subcells suffered from significant material degradation, the performance loss of the total device can be completely ascribed to the damage in the GaAs subcell. This points out the importance of high internal electric fields at the operating point.

A homogenized localizing gradient damage model with micro inertia effect

NASA Astrophysics Data System (ADS)

Wang, Zhao; Poh, Leong Hien

2018-07-01

The conventional gradient enhancement regularizes structural responses during material failure. However, it induces a spurious damage growth phenomenon, which is shown here to persist in dynamics. Similar issues were reported with the integral averaging approach. Consequently, the conventional nonlocal enhancement cannot adequately describe the dynamic fracture of quasi-brittle materials, particularly in the high strain rate regime, where a diffused damage profile precludes the development of closely spaced macrocracks. To this end, a homogenization theory is proposed to translate the micro processes onto the macro scale. Starting with simple elementary models at the micro scale to describe the fracture mechanisms, an additional kinematic field is introduced to capture the variations in deformation and velocity within a unit cell. An energetic equivalence between micro and macro is next imposed to ensure consistency at the two scales. The ensuing homogenized microforce balance resembles closely the conventional gradient expression, albeit with an interaction domain that decreases with damage, complemented by a micro inertia effect. Considering a direct single pressure bar example, the homogenized model is shown to resolve the non-physical responses obtained with conventional nonlocal enhancement. The predictive capability of the homogenized model is furthermore demonstrated by considering the spall tests of concrete, with good predictions on failure characteristics such as fragmentation profiles and dynamic tensile strengths, at three different loading rates.

Flood damage: a model for consistent, complete and multipurpose scenarios

NASA Astrophysics Data System (ADS)

Menoni, Scira; Molinari, Daniela; Ballio, Francesco; Minucci, Guido; Mejri, Ouejdane; Atun, Funda; Berni, Nicola; Pandolfo, Claudia

2016-12-01

Effective flood risk mitigation requires the impacts of flood events to be much better and more reliably known than is currently the case. Available post-flood damage assessments usually supply only a partial vision of the consequences of the floods as they typically respond to the specific needs of a particular stakeholder. Consequently, they generally focus (i) on particular items at risk, (ii) on a certain time window after the occurrence of the flood, (iii) on a specific scale of analysis or (iv) on the analysis of damage only, without an investigation of damage mechanisms and root causes. This paper responds to the necessity of a more integrated interpretation of flood events as the base to address the variety of needs arising after a disaster. In particular, a model is supplied to develop multipurpose complete event scenarios. The model organizes available information after the event according to five logical axes. This way post-flood damage assessments can be developed that (i) are multisectoral, (ii) consider physical as well as functional and systemic damage, (iii) address the spatial scales that are relevant for the event at stake depending on the type of damage that has to be analyzed, i.e., direct, functional and systemic, (iv) consider the temporal evolution of damage and finally (v) allow damage mechanisms and root causes to be understood. All the above features are key for the multi-usability of resulting flood scenarios. The model allows, on the one hand, the rationalization of efforts currently implemented in ex post damage assessments, also with the objective of better programming financial resources that will be needed for these types of events in the future. On the other hand, integrated interpretations of flood events are fundamental to adapting and optimizing flood mitigation strategies on the basis of thorough forensic investigation of each event, as corroborated by the implementation of the model in a case study.

SAFRR Tsunami Scenario: Economic Impacts and Resilience

NASA Astrophysics Data System (ADS)

Wein, A. M.; Rose, A.; Sue Wing, I.; Wei, D.

2013-12-01

Business interruption (BI) losses for the SAFRR tsunami scenario are derived from the forecasted physical damages of about 100 million at the Ports of Los Angeles (LA) and Long Beach (LB), and 700 million in marina damages, and 2 billion in inundated property damages along the California coast. Economic impacts are measured by the reduction in California's gross domestic product (GDP). The analysis involves several steps. First, estimates are made of immediate business interruption losses due to physical damage to facilities or to disruption of production. Second, total economic impacts (consisting of both direct and indirect effects) are measured by a general equilibrium (quantity and price multiplier effects) of lost production in other sectors through ripple effects upstream and downstream along the supply chain. Third, many types of resilience are applied to demonstrate their potential reductions of the impacts. At the Ports of LA and LB, a two-day port shutdown, cargo losses, and additional terminal downtimes would expose 1.2 billion of trade (import and export) value associated with over 4 billion of BI losses. The sectors potentially most affected by trade disruptions are leather, metal, and motor vehicle manufacturing. Excess capacity, inventories, export conversion, and conservation could reduce the direct trade impacts by 85%. Production recapture alone (including clearing the backlog of waiting ships) could reduce BI losses by 85%. The Port of LA commercial fishing would be subject to damages to the fleet, perished fish that cannot be landed, and lost fishing days. Although BI losses are relatively small, the southern Californian fishing sector could incur a 4% drop in output. The impacts would depend on the speed at which boats are repaired and whether lost fishing days can be made up. Ship-building and repair could also be negatively affected, but these impacts would be offset somewhat by reconstruction. Effects on commercial fishing in other locations were not closely examined to assess the impacts. Extensive damages to marinas along the California coast could result in 30 million BI losses in terms of GDP. Interestingly, the service sectors including and relating to marinas (recreation, food services, and retail) indicate possible gains (of .02-1%) from price increases greater than the losses from quantity decreases. Sectors associated with development (residential construction, water and sewage, and health care) could suffer the most with losses of .03% or less. However, these sectors will likely also be bolstered by reconstruction. Economic hardships would be localized and the resilience of the marina sector would depend on alternative moorings and excess capacity elsewhere. Inundated coastal property damages could generate 1.7 billion of BI losses. Application of sector recapture factors (e.g., using overtime) alone could reduce these losses by 80%. For the overall set of loss categories, BI losses amount to 6 billion, and resilience strategies indicate the potential to reduce these economic impacts by 80-90%.

A continuation of the Asia-Pacific Risk Index for natural disasters: extending the record for an updated analysis from 1900-2015

NASA Astrophysics Data System (ADS)

Daniell, James; Daniell, Trevor; Daniell, Katherine; Khazai, Bijan; Schaefer, Andreas; Wenzel, Friedemann

2016-04-01

In 2010, an Asia-Pacific risk index was created for the CECAR5 (Civil Engineering Conference for the Asia-Pacific Region) by Daniell et al. (2010a) for floods and earthquakes, using empirical and analytical risk data for direct as well as socio-economic community vulnerability. The socio-economic situation of countries can aggravate the physical risk of natural disaster impacts, as demonstrated by the impacts of earthquakes in Christchurch and Tohoku 2011; add to this a number of deadly typhoon (Haiyan 2013), cyclone (Yasi 2011), flood (Thailand 2011), bushfire and weather effects, and significant changes to the index in 2010 have been seen. At least 10,000 historical events have been recorded since 1900 across the Asia-Pacific region (western Pacific). The database for global socio-economic indicators was produced to allow comparison of countries in terms of their socio-economic situation for use in risk studies. In addition, a global damaging natural disasters database (CATDAT) has been created over the last 14 years to better understand the historical impact of natural disasters on the Asia-Pacific region as well as globally. Simplified hazard models have been used in conjunction with historical damage data added to human exposure. Post-flood and post-typhoon loss models have been produced this methodology. The relative country level rural and urban building inventories and historical building trends are used to define levels of vulnerability, exposure and hazard. From this, physical and community risk indices are derived for the countries of the Asia-Pacific region. It was found that the vulnerabilities in communities of developing countries such as Indonesia and the Philippines can further intensify the impact from direct damages by many times, showing the increased need for earthquake and flood risk reduction policy. Trends based on HDI and other indicators within the fields of economy, poverty, demographics, governance and environment are also presented, showing the influence of these factors on country-level fragility and resilience showing Philippines and Japan to be the highest at risk countries in absolute and relative terms. (a) Daniell, J.E., Daniell, K.A., Daniell, T.M. & B. Khazai: A country level physical and community risk index in the Asia-Pacific region for earthquakes and floods, Paper No. 0392, 5th CECAR Conference Proceedings, Sydney, Australia, 2010.

Mechanisms of poliovirus inactivation by the direct and indirect effects of ionizing radiation

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

Ward, R.L.

1980-08-01

This study was designed to measure the effects of ionizing radiation on poliovirus particles when given under conditions where either direct (in broth) or indirect (in water) effects were predominant. Under direct conditions, inactivation of poliovirus was found to be due primarily to RNA damage, although capsid damage could account for about one-third of the viral inactivation. RNA damage did not appear to be due to strand breakage and therefore was probably caused primarily by base damage or crosslink formation. Capsid damage under direct irradiation conditions did not result in significant alterations of either the sedimentation coefficients or the isoelectricmore » points of the poliovirus particles or detectable modification of the sizes of the viral proteins. It did, however, cause loss of availability to bind to host cells. Under indirect conditions no more than 25% of viral inactivation appeared to be due to RNA damage. However, the sedimentation coefficients and isoelectric points of the viral particles were greatly altered, and their abilities to bind to cells were lost at about three-fourths the rate of loss of infectivity. Capsid damage in this case did result in changes in the sizes of capsid proteins. Therefore, the majority of the radiation inactivation under indirect conditions appeared to be due to protein damage.« less

Quantitative Profiling of DNA Damage and Apoptotic Pathways in UV Damaged Cells Using PTMScan Direct

PubMed Central

Stokes, Matthew P.; Silva, Jeffrey C.; Jia, Xiaoying; Lee, Kimberly A.; Polakiewicz, Roberto D.; Comb, Michael J.

2013-01-01

Traditional methods for analysis of peptides using liquid chromatography and tandem mass spectrometry (LC-MS/MS) lack the specificity to comprehensively monitor specific biological processes due to the inherent duty cycle limitations of the MS instrument and the stochastic nature of the analytical platform. PTMScan Direct is a novel, antibody-based method that allows quantitative LC-MS/MS profiling of specific peptides from proteins that reside in the same signaling pathway. New PTMScan Direct reagents have been produced that target peptides from proteins involved in DNA Damage/Cell Cycle and Apoptosis/Autophagy pathways. Together, the reagents provide access to 438 sites on 237 proteins in these signaling cascades. These reagents have been used to profile the response to UV damage of DNA in human cell lines. UV damage was shown to activate canonical DNA damage response pathways through ATM/ATR-dependent signaling, stress response pathways and induce the initiation of apoptosis, as assessed by an increase in the abundance of peptides corresponding to cleaved, activated caspases. These data demonstrate the utility of PTMScan Direct as a multiplexed assay for profiling specific cellular responses to various stimuli, such as UV damage of DNA. PMID:23344034

A Quantitative Examination Whether Education Mitigates Stress Levels among Law Enforcement Officers

ERIC Educational Resources Information Center

Metts, Gary A.

2012-01-01

Stress is damaging if it is continual, overwhelming. and prolonged. Law enforcement officers face stressful events daily. A relationship exists between stress levels and the physical and psychological effects to the human body. Although there is a general understanding of the damage stress can do physically and psychologically, many elements that…

Experimental Investigation of the Peak Shear Strength Criterion Based on Three-Dimensional Surface Description

NASA Astrophysics Data System (ADS)

Liu, Quansheng; Tian, Yongchao; Ji, Peiqi; Ma, Hao

2018-04-01

The three-dimensional (3D) morphology of joints is enormously important for the shear mechanical properties of rock. In this study, three-dimensional morphology scanning tests and direct shear tests are conducted to establish a new peak shear strength criterion. The test results show that (1) surface morphology and normal stress exert significant effects on peak shear strength and distribution of the damage area. (2) The damage area is located at the steepest zone facing the shear direction; as the normal stress increases, it extends from the steepest zone toward a less steep zone. Via mechanical analysis, a new formula for the apparent dip angle is developed. The influence of the apparent dip angle and the average joint height on the potential contact area is discussed, respectively. A new peak shear strength criterion, mainly applicable to specimens under compression, is established by using new roughness parameters and taking the effects of normal stress and the rock mechanical properties into account. A comparison of this newly established model with the JRC-JCS model and the Grasselli's model shows that the new one could apparently improve the fitting effect. Compared with earlier models, the new model is simpler and more precise. All the parameters in the new model have clear physical meanings and can be directly determined from the scanned data. In addition, the indexes used in the new model are more rational.

Investigating the Effect of Damage Progression Model Choice on Prognostics Performance

NASA Technical Reports Server (NTRS)

Daigle, Matthew; Roychoudhury, Indranil; Narasimhan, Sriram; Saha, Sankalita; Saha, Bhaskar; Goebel, Kai

2011-01-01

The success of model-based approaches to systems health management depends largely on the quality of the underlying models. In model-based prognostics, it is especially the quality of the damage progression models, i.e., the models describing how damage evolves as the system operates, that determines the accuracy and precision of remaining useful life predictions. Several common forms of these models are generally assumed in the literature, but are often not supported by physical evidence or physics-based analysis. In this paper, using a centrifugal pump as a case study, we develop different damage progression models. In simulation, we investigate how model changes influence prognostics performance. Results demonstrate that, in some cases, simple damage progression models are sufficient. But, in general, the results show a clear need for damage progression models that are accurate over long time horizons under varied loading conditions.

Flood damage in Italy: towards an assessment model of reconstruction costs

NASA Astrophysics Data System (ADS)

Sterlacchini, Simone; Zazzeri, Marco; Genovese, Elisabetta; Modica, Marco; Zoboli, Roberto

2016-04-01

Recent decades in Italy have seen a very rapid expansion of urbanisation in terms of physical assets, while demographics have remained stable. Both the characteristics of Italian soil and anthropic development, along with repeated global climatic stress, have made the country vulnerable to floods, the intensity of which is increasingly alarming. The combination of these trends will contribute to large financial losses due to property damage in the absence of specific mitigation strategies. The present study focuses on the province of Sondrio in Northern Italy (area of about 3,200 km²), which is home to more than 180,000 inhabitants and the population is growing slightly. It is clearly a hot spot for flood exposure, as it is primarily a mountainous area where floods and flash floods hit frequently. The model we use for assessing potential flood damage determines risk scenarios by overlaying flood hazard maps and economic asset data. In Italy, hazard maps are provided by Regional Authorities through the Hydrogeological System Management Plan (PAI) based on EU Flood Directive guidelines. The PAI in the study area includes both the large plain and the secondary river system and considers three hazard scenarios of Low, Medium and High Frequency associated with return periods of 20, 200 and 500 years and related water levels. By an overlay of PAI maps and residential areas, visualized on a GIS, we determine which existing built-up areas are at risk for flood according to each scenario. Then we investigate the value of physical assets potentially affected by floods in terms of market values, using the database of the Italian Property Market Observatory (OMI), and in terms of reconstruction costs, by considering synthetic cost indexes of predominant building types (from census information) and PAI water height. This study illustrates a methodology to assess flood damage in urban settlements and aims to determine general guidelines that can be extended throughout Italy. The final objective will be to analyse how the loss prospective can change when mitigation measures, including actions to reduce the flood hazard and strategies to prevent potential consequences, are implemented. Flood impacts and the corresponding value of mitigation measures will be assessed by means of a cost-benefit analysis in accordance with the EU Floods Directive.

Climate change and mental health: a causal pathways framework.

PubMed

Berry, Helen Louise; Bowen, Kathryn; Kjellstrom, Tord

2010-04-01

Climate change will bring more frequent, long lasting and severe adverse weather events and these changes will affect mental health. We propose an explanatory framework to enhance consideration of how these effects may operate and to encourage debate about this important aspect of the health impacts of climate change. Literature review. Climate change may affect mental health directly by exposing people to trauma. It may also affect mental health indirectly, by affecting (1) physical health (for example, extreme heat exposure causes heat exhaustion in vulnerable people, and associated mental health consequences) and (2) community wellbeing. Within community, wellbeing is a sub-process in which climate change erodes physical environments which, in turn, damage social environments. Vulnerable people and places, especially in low-income countries, will be particularly badly affected. Different aspects of climate change may affect mental health through direct and indirect pathways, leading to serious mental health problems, possibly including increased suicide mortality. We propose that it is helpful to integrate these pathways in an explanatory framework, which may assist in developing public health policy, practice and research.

Influence of stacking sequence on scattering characteristics of the fundamental anti-symmetric Lamb wave at through holes in composite laminates.

PubMed

Veidt, Martin; Ng, Ching-Tai

2011-03-01

This paper investigates the scattering characteristics of the fundamental anti-symmetric (A(0)) Lamb wave at through holes in composite laminates. Three-dimensional (3D) finite element (FE) simulations and experimental measurements are used to study the physical phenomenon. Unidirectional, bidirectional, and quasi-isotropic composite laminates are considered in the study. The influence of different hole diameter to wavelength aspect ratios and different stacking sequences on wave scattering characteristics are investigated. The results show that amplitudes and directivity distribution of the scattered Lamb wave depend on these parameters. In the case of quasi-isotropic composite laminates, the scattering directivity patterns are dominated by the fiber orientation of the outer layers and are quite different for composite laminates with the same number of laminae but different stacking sequence. The study provides improved physical insight into the scattering phenomena at through holes in composite laminates, which is essential to develop, validate, and optimize guided wave damage detection and characterization techniques. © 2011 Acoustical Society of America

TiO2 nanoparticles in the marine environment: Physical effects responsible for the toxicity on algae Phaeodactylum tricornutum.

PubMed

Wang, Yixiang; Zhu, Xiaoshan; Lao, Yongmin; Lv, Xiaohui; Tao, Yi; Huang, Boming; Wang, Jiangxin; Zhou, Jin; Cai, Zhonghua

2016-09-15

Nanoscale titanium dioxide (nTiO2) has been widely used in cosmetics, catalysts, varnishes, etc., which is raising concerns about its potential hazards to the ecosystem, including the marine environment. In this study, the toxicological effect of nTiO2 on the marine phytoplankton Phaeodactylum tricornutum was carefully investigated. The results showed that nTiO2 at concentrations ≥20mg/L could significantly inhibit P. tricornutum growth. The 5-day EC50 of nTiO2 to P. tricornutum growth is 167.71mg/L. Interestingly, nTiO2 was found to exert its most severe inhibition effects on the first day of exposure, at a lower EC50 of 12.65mg/L. During the experiment, nTiO2 aggregates were found to entrap algae cells, which is likely responsible for the observed toxic effects. Direct physical effects such as cell wall damage from the algae entrapment were confirmed by flow cytometry and TEM imaging. Moreover, low indirect effects such as shading and oxidative stress were observed, which supported the idea that direct physical effects could be the dominant factor that causes nTiO2 toxicity in P. tricornutum. Our research provides direct evidence for the toxicological impact of nTiO2 on marine microalgae, which will help us to build a good understanding of the ecological risks of nanoparticles in the marine environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of the Damage Potential resulting from Avalanche Risks, Case Study Galtür (Tyrol, Austria)

NASA Astrophysics Data System (ADS)

Keiler, M.

2003-04-01

Reports on catastrophes with high damage caused by natural hazards seem to have increased in number recently. A new trend in dealing with these natural processes leads to the integration of risk into natural hazards evaluations and approaches of integral risk management. The risk resulting from natural hazards can be derived from the combination of parameters of physical processes (intensity and recurrence probability) and damage potential (probability of presence and expected damage value). Natural hazard research focuses mainly on the examination, modelling and estimation of individual geomorphological processes as well as on future developments caused by climate change. Even though damage potential has been taken into account more frequently, quantifying statements are still missing. Due to the changes of the socio-economic structures in mountain regions (urban sprawl, population growth, increased mobility and tourism) these studies are mandatory. This study presents a conceptual method that records the damage potential (probability of physical presence, evaluation of buildings) and shows the development of the damage potential resulting from avalanches since 1950. The study area is the community of Galtür, Austria. 36 percent of the existing buildings are found in officially declared avalanche hazard zones. The majority of these buildings are either agricultural or accommodation facilities. Additionally, the effects of physical planning and/or technical measures on the spatial development of the potential damage are illustrated. The results serve to improve risk determination and point out an unnoticed increase of damage potential and risk in apparently safe settlement areas.

Radioresistance of GGG Sequences to Prompt Strand Break Formation from Direct-Type Radiation Damage

PubMed Central

Black, Paul J.; Miller, Adam S.; Hayes, Jeffrey J.

2016-01-01

Purpose As humans, we are constantly exposed to ionizing radiation from natural, man-made and cosmic sources which can damage DNA, leading to deleterious effects including cancer incidence. In this work we introduce a method to monitor strand breaks resulting from damage due to the direct effect of ionizing radiation and provide evidence for sequence-dependent effects leading to strand breaks. Materials and methods To analyze only DNA strand breaks caused by radiation damage due to the direct effect of ionizing radiation, we combined an established technique to generate dehydrated DNA samples with a technique to analyze single strand breaks on short oligonucleotide sequences via denaturing gel electrophoresis. Results We find that direct damage primarily results in a reduced number of strand breaks in guanine triplet regions (GGG) when compared to isolated guanine (G) bases with identical flanking base context. In addition, we observe strand break behavior possibly indicative of protection of guanine bases when flanked by pyrimidines, and sensitization of guanine to strand break when flanked by adenine (A) bases in both isolated G and GGG cases. Conclusions These observations provide insight into the strand break behavior in GGG regions damaged via the direct effect of ionizing radiation. In addition, this could be indicative of DNA sequences that are naturally more susceptible to strand break due to the direct effect of ionizing radiation. PMID:27349757

PPARGC1A variation associated with DNA damage, diabetes, and cardiovascular diseases: the Boston Puerto Rican Health Study.

PubMed

Lai, Chao-Qiang; Tucker, Katherine L; Parnell, Laurence D; Adiconis, Xian; García-Bailo, Bibiana; Griffith, John; Meydani, Mohsen; Ordovás, José M

2008-04-01

Individuals with type 2 diabetes exhibit higher DNA damage and increased risk of cardiovascular disease (CVD). However, mechanisms underlying the association between DNA damage and development of type 2 diabetes and CVD are not understood. We sought to link peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PPARGC1A), a master transcriptional regulator of mitochondrial oxidative phosphorylation and cellular energy metabolism, with DNA damage, type 2 diabetes, and CVD. We measured DNA damage as urinary 8-hydroxydeoxyguanosine (8-OHdG) concentration and examined the relationship between nine PPARGC1A genetic variants, DNA damage, type 2 diabetes, and self-reported CVD in 959 participants of the Boston Puerto Rican Health Study. With respect to urinary 8-OHdG, PPARGC1A variants showed significant association, and PPARGC1A haplotypes exhibited significant association after correction for multiple testing. Two independent PPARGC1A variants associated significantly with type 2 diabetes (odds ratios [ORs] 1.35 and 2.46; P = 0.045 and <0.001). Carriers of minor alleles of two other PPARGC1A variants, both in strong linkage disequilibrium and associated with lower DNA damage, showed lower prevalence of CVD (ORs 0.53 and 0.65; P = 0.030 and 0.175). Moreover, we found that physical activity correlated negatively with DNA damage. It is plausible that low physical activity combined with risk haplotyes contribute to the high prevalence of type 2 diabetes in this population. We propose that PPARGC1A influences development of type 2 diabetes and CVD via DNA damage. Increasing physical activity, which induces PPARGC1A expression, is a potential strategy to slow DNA damage, thereby decreasing the risk of CVD for individuals with type 2 diabetes.

[Ophthalmological opinions for liability affairs material damage (Part I) (author's transl)].

PubMed

Burggraf, H

1979-02-01

German law abides anyone reponsible for the damage he or she has caused to another person's property or corporal integrity. This includes all medical costs directed towards the restitution of health as well as economical damage in direct consequence of the corporal damage. An ophthalmological expert is to state his opinion therefore in accordance with the specific conditions of every individual case and not just according to general charts. Financial compensation is only granted for the actual results of damage inquestion. Prior damage and disability have to be remarked but not to justify a financial compensation. The question of smart-money is dealt with in Part II.

On multi-site damage identification using single-site training data

NASA Astrophysics Data System (ADS)

Barthorpe, R. J.; Manson, G.; Worden, K.

2017-11-01

This paper proposes a methodology for developing multi-site damage location systems for engineering structures that can be trained using single-site damaged state data only. The methodology involves training a sequence of binary classifiers based upon single-site damage data and combining the developed classifiers into a robust multi-class damage locator. In this way, the multi-site damage identification problem may be decomposed into a sequence of binary decisions. In this paper Support Vector Classifiers are adopted as the means of making these binary decisions. The proposed methodology represents an advancement on the state of the art in the field of multi-site damage identification which require either: (1) full damaged state data from single- and multi-site damage cases or (2) the development of a physics-based model to make multi-site model predictions. The potential benefit of the proposed methodology is that a significantly reduced number of recorded damage states may be required in order to train a multi-site damage locator without recourse to physics-based model predictions. In this paper it is first demonstrated that Support Vector Classification represents an appropriate approach to the multi-site damage location problem, with methods for combining binary classifiers discussed. Next, the proposed methodology is demonstrated and evaluated through application to a real engineering structure - a Piper Tomahawk trainer aircraft wing - with its performance compared to classifiers trained using the full damaged-state dataset.

Physical Processes and Applications of the Monte Carlo Radiative Energy Deposition (MRED) Code

NASA Astrophysics Data System (ADS)

Reed, Robert A.; Weller, Robert A.; Mendenhall, Marcus H.; Fleetwood, Daniel M.; Warren, Kevin M.; Sierawski, Brian D.; King, Michael P.; Schrimpf, Ronald D.; Auden, Elizabeth C.

2015-08-01

MRED is a Python-language scriptable computer application that simulates radiation transport. It is the computational engine for the on-line tool CRÈME-MC. MRED is based on c++ code from Geant4 with additional Fortran components to simulate electron transport and nuclear reactions with high precision. We provide a detailed description of the structure of MRED and the implementation of the simulation of physical processes used to simulate radiation effects in electronic devices and circuits. Extensive discussion and references are provided that illustrate the validation of models used to implement specific simulations of relevant physical processes. Several applications of MRED are summarized that demonstrate its ability to predict and describe basic physical phenomena associated with irradiation of electronic circuits and devices. These include effects from single particle radiation (including both direct ionization and indirect ionization effects), dose enhancement effects, and displacement damage effects. MRED simulations have also helped to identify new single event upset mechanisms not previously observed by experiment, but since confirmed, including upsets due to muons and energetic electrons.

Development of Hydrologic Characterization Technology of Fault Zones (in Japanese; English)

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

Karasaki, Kenzi; Onishi, Tiemi; Wu, Yu-Shu

2008-03-31

Through an extensive literature survey we find that there is very limited amount of work on fault zone hydrology, particularly in the field using borehole testing. The common elements of a fault include a core, and damage zones. The core usually acts as a barrier to the flow across it, whereas the damage zone controls the flow either parallel to the strike or dip of a fault. In most of cases the damage zone isthe one that is controlling the flow in the fault zone and the surroundings. The permeability of damage zone is in the range of two tomore » three orders of magnitude higher than the protolith. The fault core can have permeability up to seven orders of magnitude lower than the damage zone. The fault types (normal, reverse, and strike-slip) by themselves do not appear to be a clear classifier of the hydrology of fault zones. However, there still remains a possibility that other additional geologic attributes and scaling relationships can be used to predict or bracket the range of hydrologic behavior of fault zones. AMT (Audio frequency Magneto Telluric) and seismic reflection techniques are often used to locate faults. Geochemical signatures and temperature distributions are often used to identify flow domains and/or directions. ALSM (Airborne Laser Swath Mapping) or LIDAR (Light Detection and Ranging) method may prove to be a powerful tool for identifying lineaments in place of the traditional photogrammetry. Nonetheless not much work has been done to characterize the hydrologic properties of faults by directly testing them using pump tests. There are some uncertainties involved in analyzing pressure transients of pump tests: both low permeability and high permeability faults exhibit similar pressure responses. A physically based conceptual and numerical model is presented for simulating fluid and heat flow and solute transport through fractured fault zones using a multiple-continuum medium approach. Data from the Horonobe URL site are analyzed to demonstrate the proposed approach and to examine the flow direction and magnitude on both sides of a suspected fault. We describe a strategy for effective characterization of fault zone hydrology. We recommend conducting a long term pump test followed by a long term buildup test. We do not recommend isolating the borehole into too many intervals. We do recommend ensuring durability and redundancy for long term monitoring.« less

Physical evidence of predatory behavior in Tyrannosaurus rex.

PubMed

DePalma, Robert A; Burnham, David A; Martin, Larry D; Rothschild, Bruce M; Larson, Peter L

2013-07-30

Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota.

Physical evidence of predatory behavior in Tyrannosaurus rex

NASA Astrophysics Data System (ADS)

DePalma, Robert A., II; Burnham, David A.; Martin, Larry D.; Rothschild, Bruce M.; Larson, Peter L.

2013-07-01

Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota.

Physical evidence of predatory behavior in Tyrannosaurus rex

PubMed Central

DePalma, Robert A.; Burnham, David A.; Martin, Larry D.; Rothschild, Bruce M.; Larson, Peter L.

2013-01-01

Feeding strategies of the large theropod, Tyrannosaurus rex, either as a predator or a scavenger, have been a topic of debate previously compromised by lack of definitive physical evidence. Tooth drag and bone puncture marks have been documented on suggested prey items, but are often difficult to attribute to a specific theropod. Further, postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present. Here we report definitive evidence of predation by T. rex: a tooth crown embedded in a hadrosaurid caudal centrum, surrounded by healed bone growth. This indicates that the prey escaped and lived for some time after the injury, providing direct evidence of predatory behavior by T. rex. The two traumatically fused hadrosaur vertebrae partially enclosing a T. rex tooth were discovered in the Hell Creek Formation of South Dakota. PMID:23858435

A three-dimensional `Kaiser damage-memory' effect through true-triaxial loading

NASA Astrophysics Data System (ADS)

Meredith, P. G.; Browning, J.; Harland, S. R.; Healy, D.; Stuart, C.; Mitchell, T. M.

2017-12-01

Microcrack damage leading to failure in rocks evolves in response to differential loading. The vast majority of experimental studies investigate damage evolution, the `Kaiser damage-memory' effect, and rock failure using conventional triaxial stress states (σ1 > σ2 = σ3). Such stress states develop a crack population that displays cylindrical transverse isotropy. However, in nature the stress state is in general truly triaxial (σ1 > σ2 > σ3) and experiments that utilise such loading conditions can generate crack populations that display planar transverse isotropy which in turn influences properties such as permeability and strength. We investigate the evolution of crack damage under both conventional and true triaxial stress conditions using results from measurements made on cubic samples of sandstone deformed in three orthogonal directions with independently controlled stress paths. We have measured, simultaneously with stress and strain, the changes in ultrasonic compressional and shear wave velocities in the three principal directions, together with the bulk acoustic emission (AE) output. Changes in acoustic wave velocities are associated with both elastic closure and opening of pre-existing cracks, and the inelastic formation of new cracks. By contrast, AE is only associated with the inelastic growth of new crack damage and as such, we use the onset of AE to determine the initiation of new crack damage. By mapping these damage onsets under both conventional triaxial and true triaxial sequential cyclic loading, we have shown that `damage envelopes' evolve dynamically and can be pushed closer to the failure envelope. Whether a stress state has been `visited' before is key to determining and understanding damage states. Crack damage populations can be generated with multiple orientations depending on the arrangement of loading directions and hence principal stress directions. The sequential cyclic loading tests show that further damage in any one population commences only when the previous maximum differential stress `seen' by that population is exceeded. Understanding anisotropic damage is important for applying the results of true-triaxial tests and hence better replicating natural fractured systems.

Massive cellular disruption occurs during early imbibition of Cuphea seeds containing crystallized triacylglycerols.

PubMed

Volk, Gayle M; Crane, Jennifer; Caspersen, Ann M; Hill, Lisa M; Gardner, Candice; Walters, Christina

2006-11-01

The transition from anhydrobiotic to hydrated state occurs during early imbibition of seeds and is lethal if lipid reserves in seeds are crystalline. Low temperatures crystallize lipids during seed storage. We examine the nature of cellular damage observed in seeds of Cuphea wrightii and C. lanceolata that differ in triacylglycerol composition and phase behavior. Intracellular structure, observed using transmission electron microscopy, is profoundly and irreversibly perturbed if seeds with crystalline triacylglycerols are imbibed briefly. A brief heat treatment that melts triacylglycerols before imbibition prevents the loss of cell integrity; however, residual effects of cold treatments in C. wrightii cells are reflected by the apparent coalescence of protein and oil bodies. The timing and temperature dependence of cellular changes suggest that damage arises via a physical mechanism, perhaps as a result of shifts in hydrophobic and hydrophilic interactions when triacylglycerols undergo phase changes. Stabilizers of oil body structure such as oleosins that rely on a balance of physical forces may become ineffective when triacylglycerols crystallize. Recent observations linking poor oil body stability and poor seed storage behavior are potentially explained by the phase behavior of the storage lipids. These findings directly impact the feasibility of preserving genetic resources from some tropical and subtropical species.

PHYSICAL AND ECONOMIC DAMAGE FUNCTIONS FOR AIR POLLUTANTS BY RECEPTOR

EPA Science Inventory

This study is primarily concerned with evaluating regional economic damages to human health, material, and vegetation and of property soiling resulting from air pollution. This study represents a step forward in methodological development of air pollution damage estimation. It at...

Mechanisms of carbon nanotube-induced toxicity: Focus on oxidative stress

PubMed Central

Shvedova, Anna A.; Pietroiusti, Antonio; Fadeel, Bengt; Kagan, Valerian E.

2015-01-01

Nanotechnologies are emerging as highly promising technologies in many sectors in the society. However, the increasing use of engineered nanomaterials also raises concerns about inadvertent exposure to these materials and the potential for adverse effects on human health and the environment. Despite several years of intensive investigations, a common paradigm for the understanding of nanoparticle-induced toxicity remains to be firmly established. Here, the so-called oxidative stress paradigm is scrutinized. Does oxidative stress represent a secondary event resulting inevitably from disruption of biochemical processes and the demise of the cell, or a specific, non-random event that plays a role in the induction of cellular damage e.g. apoptosis? The answer to this question will have important ramifications for the development of strategies for mitigation of adverse effects of nanoparticles. Recent examples of global lipidomics studies of nanoparticle-induced tissue damage are discussed along with proteomics and transcriptomics approaches to achieve a comprehensive understanding of the complex and interrelated molecular changes in cells and tissues exposed to nanoparticles. We also discuss instances of non-oxidative stress-mediated cellular damage resulting from direct physical interference of nanomaterials with cellular structures. PMID:22513272

Damage location and quantification of a pretensioned concrete beam using stochastic subspace identification

NASA Astrophysics Data System (ADS)

Cancelli, Alessandro; Micheli, Laura; Laflamme, Simon; Alipour, Alice; Sritharan, Sri; Ubertini, Filippo

2017-04-01

Stochastic subspace identification (SSID) is a first-order linear system identification technique enabling modal analysis through the time domain. Research in the field of structural health monitoring has demonstrated that SSID can be used to successfully retrieve modal properties, including modal damping ratios, using output-only measurements. In this paper, the utilization of SSID for indirectly retrieving structures' stiffness matrix was investigated, through the study of a simply supported reinforced concrete beam subjected to dynamic loads. Hence, by introducing a physical model of the structure, a second-order identification method is achieved. The reconstruction is based on system condensation methods, which enables calculation of reduced order stiffness, damping, and mass matrices for the structural system. The methods compute the reduced order matrices directly from the modal properties, obtained through the use of SSID. Lastly, the reduced properties of the system are used to reconstruct the stiffness matrix of the beam. The proposed approach is first verified through numerical simulations and then validated using experimental data obtained from a full-scale reinforced concrete beam that experienced progressive damage. Results show that the SSID technique can be used to diagnose, locate, and quantify damage through the reconstruction of the stiffness matrix.

Radiation damage in protein crystals examined under various conditions by different methods.

PubMed

Garman, Elspeth F; Nave, Colin

2009-03-01

Investigation of radiation damage in protein crystals has progressed in several directions over the past couple of years. There have been improvements in the basic procedures such as calibration of the incident X-ray intensity and calculation of the dose likely to be deposited in a crystal of known size and composition with this intensity. There has been increased emphasis on using additional techniques such as optical, Raman or X-ray spectroscopy to complement X-ray diffraction. Apparent discrepancies between the results of different techniques can be explained by the fact that they are sensitive to different length scales or to changes in the electronic state rather than to movement of atoms. Investigations have been carried out at room temperature as well as cryo-temperatures and, in both cases, with the introduction of potential scavenger molecules. These and other studies are leading to an overall description of the changes which can occur when a protein crystal is irradiated with X-rays at both cryo- and room temperatures. Results from crystallographic and spectroscopic radiation-damage experiments can be reconciled with other studies in the field of radiation physics and chemistry.

Toward dual hematopoietic stem-cell transplantation and solid-organ transplantation for sickle-cell disease

PubMed Central

Levine, Jeffrey; Abt, Peter; Henry, David; Porter, David L.

2018-01-01

Sickle-cell disease (SCD) leads to recurrent vaso-occlusive crises, chronic end-organ damage, and resultant physical, psychological, and social disabilities. Although hematopoietic stem-cell transplantation (HSCT) is potentially curative for SCD, this procedure is associated with well-recognized morbidity and mortality and thus is ideally offered only to patients at high risk of significant complications. However, it is difficult to identify patients at high risk before significant complications have occurred, and once patients experience significant organ damage, they are considered poor candidates for HSCT. In turn, patients who have experienced long-term organ toxicity from SCD such as renal or liver failure may be candidates for solid-organ transplantation (SOT); however, the transplanted organs are at risk of damage by the original disease. Thus, dual HSCT and organ transplantation could simultaneously replace the failing organ and eliminate the underlying disease process. Advances in HSCT conditioning such as reduced-intensity regimens and alternative donor selection may expand both the feasibility of and potential donor pool for transplantation. This review summarizes the current state of HSCT and organ transplantation in SCD and discusses future directions and the clinical feasibility of dual HSCT/SOT. PMID:29535106

3D-analysis of plant microstructures: advantages and limitations of synchrotron X-ray microtomography

NASA Astrophysics Data System (ADS)

Matsushima, U.; Graf, W.; Zabler, S.; Manke, I.; Dawson, M.; Choinka, G.; Hilger, A.; Herppich, W. B.

2013-01-01

Synchrotron X-ray computer microtomography was used to analyze the microstructure of rose peduncles. Samples from three rose cultivars, differing in anatomy, were scanned to study the relation between tissue structure and peduncles mechanical strength. Additionally, chlorophyll fluorescence imaging and conventional light microscopy was applied to quantify possible irradiation-induced damage to plant physiology and tissue structure. The spatial resolution of synchrotron X-ray computer microtomography was sufficiently high to investigate the complex tissues of intact rose peduncles without the necessity of any preparation. However, synchrotron X-radiation induces two different types of damage on irradiated tissues. First, within a few hours after first X-ray exposure, there is a direct physical destruction of cell walls. In addition, a slow and delayed destruction of chlorophyll and, consequently, of photosynthetic activity occurred within hours/ days after the exposure. The results indicate that synchrotron X-ray computer microtomography is well suited for three-dimensional visualization of the microstructure of rose peduncles. However, in its current technique, synchrotron X-ray computer microtomography is not really non-destructive but induce tissue damage. Hence, this technique needs further optimization before it can be applied for time-series investigations of living plant materials

Contribution of indirect effects to clustered damage in DNA irradiated with protons.

PubMed

Pachnerová Brabcová, K; Štěpán, V; Karamitros, M; Karabín, M; Dostálek, P; Incerti, S; Davídková, M; Sihver, L

2015-09-01

Protons are the dominant particles both in galactic cosmic rays and in solar particle events and, furthermore, proton irradiation becomes increasingly used in tumour treatment. It is believed that complex DNA damage is the determining factor for the consequent cellular response to radiation. DNA plasmid pBR322 was irradiated at U120-M cyclotron with 30 MeV protons and treated with two Escherichia coli base excision repair enzymes. The yields of SSBs and DSBs were analysed using agarose gel electrophoresis. DNA has been irradiated in the presence of hydroxyl radical scavenger (coumarin-3-carboxylic acid) in order to distinguish between direct and indirect damage of the biological target. Pure scavenger solution was used as a probe for measurement of induced OH· radical yields. Experimental OH· radical yield kinetics was compared with predictions computed by two theoretical models-RADAMOL and Geant4-DNA. Both approaches use Geant4-DNA for description of physical stages of radiation action, and then each of them applies a distinct model for description of the pre-chemical and chemical stage. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

[Socio-economic costs of road traffic accidents in the Canary Islands, Spain, in 1997].

PubMed

López, J; Serrano, P; Duque, B; Artiles, J

2001-01-01

To evaluate the economic impact in terms of direct and indirect costs road traffic accidents in Canarias Islands (Spain) in 1997. The cost-of-illness method was used. Direct and indirect costs were estimated using prevalence cost, i.e., the costs produced in 1997. Direct costs were divided into health services costs, insurance administration costs and the costs of material damage to the vehicles. Indirect costs were obtained through transformation of physical units into monetary units using the approach of human capital theory. The total cost of road traffic accidents was 39,887.16 million pesetas, equivalent to 24,470 for each inhabitant of the Canary Islands and representing 1.3% of the GNP in this region. The total direct cost was 32,559.67 million pesetas, constituting 82% of the total, which was distributed according to the different concepts analyzed: health service costs: 2,407.40 million pesetas; insurance administration costs, 13,415.89 million pesetas and the costs of material damages to the vehicles: 16,736.38 million pesetas. The total indirect costs was 7,327.49 million pesetas, accounting for 18% of the total costs, which was distributed in premature mortality (6,884.88 million pesetas) and absenteeism from work (442.61 million pesetas). Although this study adopts a conservative approach by omitting costs associated with pain and suffering, permanent disability, and those of at-home care provided by the family, the hight socio-economic cost of road traffic accidents clearly indicates the need for the different administrations of the Canary Islands to collaborate in implementing preventive measures.

Bundled automobile insurance coverage and accidents.

PubMed

Li, Chu-Shiu; Liu, Chwen-Chi; Peng, Sheng-Chang

2013-01-01

This paper investigates the characteristics of automobile accidents by taking into account two types of automobile insurance coverage: comprehensive vehicle physical damage insurance and voluntary third-party liability insurance. By using a unique data set in the Taiwanese automobile insurance market, we explore the bundled automobile insurance coverage and the occurrence of claims. It is shown that vehicle physical damage insurance is the major automobile coverage and affects the decision to purchase voluntary liability insurance coverage as a complement. Moreover, policyholders with high vehicle physical damage insurance coverage have a significantly higher probability of filing vehicle damage claims, and if they additionally purchase low voluntary liability insurance coverage, their accident claims probability is higher than those who purchase high voluntary liability insurance coverage. Our empirical results reveal that additional automobile insurance coverage information can capture more driver characteristics and driving behaviors to provide useful information for insurers' underwriting policies and to help analyze the occurrence of automobile accidents. Copyright © 2012 Elsevier Ltd. All rights reserved.

Characterization of Damage Progression in SCS-6/timetal 21S (0)4 Under Thermomechanical Fatigue Loadings

NASA Technical Reports Server (NTRS)

Castelli, Michael G.

1994-01-01

A detailed experimental investigation was performed at a single maximum cyclic stress (sigma max) level to physically characterize the progression of thermomechanical fatigue (lW) damage in continuously reinforced (0 deg) SCS-6/Timetal 21S, a titanium matrix composite. In-phase (IP) and out of-phase (OP) loadings were investigated at sigma max = 1000 MPa with a temperature cycle from 150 to 6500 C. Damage progression, in terms of macroscopic property degradation, was experimentally quantified through an advanced TMF test methodology which incorporates explicit measurements of the isothermal static moduli at the TMF temperature extremes and the coefficient of thermal expansion (CTE) as functions of the TMF cycles. Detailed characterization of the physical damage progression at the microstructural level was performed by interrupting multiple TMF tests at various stages of mechanical property degradation and analyzing the microstructure through extensive destructive metallography. Further, the extent of damage was also quantified through residual static strength measurements. Results indicated that damage initiation occurred very early in cyclic life (N less than 0.1Nf) for both the IP and OP TMF loadings. IP TMF damage was found to be dominated by fiber breakage with a physical damage progression in the microstructure which was difficult to quantify. OP TMF loadings produced matrix cracking exclusively associated with surface initiations. Here, damage progression was easily distinguished in terms of both the number of cracks and their relative inward progressions toward the outer fiber rows with increased cycling. The point at which the leading cracks reached the outer fiber rows (when localized fiber/matrix de-bonding and matrix crack bridging occurred) appeared to be reflected in the macroscopic property degradation curves.

DNA damage induced by ascorbate in the presence of Cu2+.

PubMed

Kobayashi, S; Ueda, K; Morita, J; Sakai, H; Komano, T

1988-01-25

DNA damage induced by ascorbate in the presence of Cu2+ was investigated by use of bacteriophage phi X174 double-stranded supercoiled DNA and linear restriction fragments as substrates. Single-strand cleavage was induced when supercoiled DNA was incubated with 5 microM-10 mM ascorbate and 50 microM Cu2+ at 37 degrees C for 10 min. The induced DNA damage was analyzed by sequencing of fragments singly labeled at their 5'- or 3'-end. DNA was cleaved directly and almost uniformly at every nucleotide by ascorbate and Cu2+. Piperidine treatment after the reaction showed that ascorbate and Cu2+ induced another kind of DNA damage different from the direct cleavage. The damage proceeded to DNA cleavage by piperidine treatment and was sequence-specific rather than random. These results indicate that ascorbate induces two classes of DNA damage in the presence of Cu2+, one being direct strand cleavage, probably via damage to the DNA backbone, and the other being a base modification labile to alkali treatment. These two classes of DNA damage were inhibited by potassium iodide, catalase and metal chelaters, suggesting the involvement of radicals generated from ascorbate hydroperoxide.

Lateral damage in graphene carved by high energy focused gallium ion beams

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

Liao, Zhongquan, E-mail: zhongquan.liao@ikts-md.fraunhofer.de; Dresden Center for Nanoanalysis; Institute for Materials Science and Max Bergmann Center of Biomaterials, Technische Universität Dresden, Hallwachsstraße 3, 01069 Dresden

2015-07-06

Raman mapping is performed to study the lateral damage in supported monolayer graphene carved by 30 keV focused Ga{sup +} beams. The evolution of the lateral damage is tracked based on the profiles of the intensity ratio between the D (1341 cm{sup −1}) and G (1582 cm{sup −1}) peaks (I{sub D}/I{sub G}) of the Raman spectra. The I{sub D}/I{sub G} profile clearly reveals the transition from stage 2 disorder into stage 1 disorder in graphene along the direction away from the carved area. The critical lateral damage distance spans from <1 μm up to more than 30 μm in the experiment, depending on the parametersmore » used for carving the graphene. The wide damage in the lateral direction is attributed to the deleterious tail of unfocused ions in the ion beam probe. The study raises the attention on potential sample damage during direct patterning of graphene nanostructures using the focused ion beam technique. Minimizing the total carving time is recommended to mitigate the lateral damage.« less

49 CFR 1242.78 - Employees performing clerical and accounting functions, and loss and damage claims processing...

Code of Federal Regulations, 2010 CFR

2010-10-01

... functions, and loss and damage claims processing (accounts XX-55-76 and XX-55-78). 1242.78 Section 1242.78... Employees performing clerical and accounting functions, and loss and damage claims processing (accounts XX-55-76 and XX-55-78). If the sum of the direct freight and the direct passenger expenses is more than...

Surface crack analysis applied to impact damage in a thick graphite-epoxy composite

NASA Technical Reports Server (NTRS)

Poe, C. C., Jr.; Harris, C. E.; Morris, D. H.

1988-01-01

The residual tensile strength of a thick graphite/epoxy composite with impact damage was predicted using surface crack analysis. The damage was localized to a region directly beneath the impact site and extended only part way through the laminate. The damaged region contained broken fibers, and the locus of breaks in each layer resembled a crack perpendicular to the direction of the fibers. In some cases, the impacts broke fibers without making a visible crater. The impact damage was represented as a semi-elliptical surface crack with length and depth equal to that of the impact damage. The maximum length and depth of the damage were predicted with a stress analysis and a maximum shear stress criterion. The predictions and measurements of strength were in good agreement.

Surface crack analysis applied to impact damage in a thick graphite/epoxy composite

NASA Technical Reports Server (NTRS)

Poe, Clarence C., Jr.; Harris, Charles E.; Morris, Don H.

1990-01-01

The residual tensile strength of a thick graphite/epoxy composite with impact damage was predicted using surface crack analysis. The damage was localized to a region directly beneath the impact site and extended only part way through the laminate. The damaged region contained broken fibers, and the locus of breaks in each layer resembled a crack perpendicular to the direction of the fibers. In some cases, the impacts broke fibers without making a visible crater. The impact damage was represented as a semi-elliptical surface crack with length and depth equal to that of the impact damage. The maximum length and depth of the damage were predicted with a stress analysis and a maximum shear stress criterion. The predictions and measurements of strength were in good agreement.

Persistence of Space Radiation-Induced Cytogenetic Damage in the Blood Lymphocytes of Astronauts and the Effects of Repeat Long Duration Space Missions

NASA Technical Reports Server (NTRS)

George, Kerry A.; Cucinotta, Francis A.

2009-01-01

The yield of chromosome damage in astronauts blood lymphocytes has been shown to increase after long duration space missions of a few months or more. This provides a useful in vivo measurement of space radiation induced damage that takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. We present our latest follow-up analyses of chromosome damage in astronauts blood lymphocytes assessed by fluorescence in situ hybridization (FISH) chromosome painting and collected at various times, from directly after return from space to several years after flight. For most individuals the analysis of individual time-courses for translocations revealed a temporal decline of yields with different half-lives. Dose was derived from frequencies of chromosome exchanges using preflight calibration curves, and estimates derived from samples collected a few days after return to earth lie within the range expected from physical dosimetry. However, a temporal decline in yields may indicate complications with the use of stable aberrations for retrospective dose reconstruction, and the differences in the decay time may reflect individual variability in risk from space radiation exposure. Limited data on three individuals who have participated in repeat long duration space flights indicates a lack of correlation between time in space and translocation yields, and show a possible adaptive response to space radiation exposure.

Increase in recombination rate in Arabidopsis thaliana plants sharing gaseous environment with X-ray and UVC-irradiated plants depends on production of radicals.

PubMed

Zemp, Franz J; Sidler, Corinne; Kovalchuk, Igor

2012-07-01

X-ray and UVC are the two physical agents that damage DNA directly, with both agents capable of inducing double-strand breaks. Some of our recent work has demonstrated that local exposure to UVC results in a systemic increase in recombination frequency, suggesting that information about exposure can be passed from damaged to non-damaged tissue. Indeed, we recently showed that plants sharing the same enclosed environment with UVC-irradiated plants exhibit similar increase in homologous recombination frequency as irradiated plants. Here, we further tested whether yet another DNA-damaging agent, X-ray, is capable of increasing recombination rate (RR) in neighboring plants grown in a Petri dish. To test this, we grew plants exposed to X-ray or UVC irradiation in an enclosed environment next to non-exposed plants. We found that both X-ray and UVC-irradiated plants and neighboring plants exhibited comparable increases in the levels of strand breaks and the RR. We further showed that pre-exposure of plants to radical scavenger DMSO substantially alleviates the radiation-induced increase in RR and prevents formation of bystander signal. Our results suggest that the increase in RR in bystander plants can also be triggered by X-ray and that radicals may play some role in initiation or maintenance of this signal.

Increase in recombination rate in Arabidopsis thaliana plants sharing gaseous environment with X-ray and UVC-irradiated plants depends on production of radicals

PubMed Central

Zemp, Franz J.; Sidler, Corinne; Kovalchuk, Igor

2012-01-01

X-ray and UVC are the two physical agents that damage DNA directly, with both agents capable of inducing double-strand breaks. Some of our recent work has demonstrated that local exposure to UVC results in a systemic increase in recombination frequency, suggesting that information about exposure can be passed from damaged to non-damaged tissue. Indeed, we recently showed that plants sharing the same enclosed environment with UVC-irradiated plants exhibit similar increase in homologous recombination frequency as irradiated plants. Here, we further tested whether yet another DNA-damaging agent, X-ray, is capable of increasing recombination rate (RR) in neighboring plants grown in a Petri dish. To test this, we grew plants exposed to X-ray or UVC irradiation in an enclosed environment next to non-exposed plants. We found that both X-ray and UVC-irradiated plants and neighboring plants exhibited comparable increases in the levels of strand breaks and the RR. We further showed that pre-exposure of plants to radical scavenger DMSO substantially alleviates the radiation-induced increase in RR and prevents formation of bystander signal. Our results suggest that the increase in RR in bystander plants can also be triggered by X-ray and that radicals may play some role in initiation or maintenance of this signal. PMID:22751301

Structural changes of polymer-coated microgranules and excipients on tableting investigated by microtomography using synchrotron X-ray radiation.

PubMed

Kajihara, Ryusuke; Noguchi, Shuji; Iwao, Yasunori; Suzuki, Yoshio; Terada, Yasuko; Uesugi, Kentaro; Itai, Shigeru

2015-03-15

Multiple-unit tablets consisting of polymer-coated microgranules and excipients have a number of advantageous pharmaceutical properties. Polymer-coated microgranules are known to often lose their functionality because of damage to the polymer coating caused by tableting, and the mechanism of polymer coating damage as well as the structural changes of excipients upon tableting had been investigated but without in-situ visualization and quantitative analysis. To elucidate the mechanism of coating damage, the internal structures of multiple-unit tablets were investigated by X-ray computed microtomography using synchrotron X-rays. Cross sectional images of the tablets with sub-micron spatial resolution clearly revealed that void spaces remained around the compressed excipient particles in the tablets containing an excipient composed of cellulose and lactose (Cellactose(®) 80), whereas much smaller void spaces remained in the tablets containing an excipient made of sorbitol (Parteck(®) SI 150). The relationships between the void spaces and the physical properties of the tablets such as hardness and disintegration were investigated. Damage to the polymer coating in tablets was found mainly where polymer-coated microgranules were in direct contact with each other in both types of tablets, which could be attributed to the difference in hardness of excipient particles and the core of the polymer-coated microgranules. Copyright © 2015 Elsevier B.V. All rights reserved.

On mechanical mechanism of damage evolution in articular cartilage.

PubMed

Men, Yu-Tao; Jiang, Yan-Long; Chen, Ling; Zhang, Chun-Qiu; Ye, Jin-Duo

2017-09-01

Superficial lesions of cartilage are the direct indication of osteoarthritis. To investigate the mechanical mechanism of cartilage with micro-defect under external loading, a new plain strain numerical model with micro-defect was proposed and damage evolution progression in cartilage over time has been simulated, the parameter were studied including load style, velocity of load and degree of damage. The new model consists of the hierarchical structure of cartilage and depth-dependent arched fibers. The numerical results have shown that not only damage of the cartilage altered the distribution of the stress but also matrix and fiber had distinct roles in affecting cartilage damage, and damage in either matrix or fiber could promote each other. It has been found that the superficial cracks in cartilage spread preferentially along the tangent direction of the fibers. It is the arched distribution form of fibers that affects the crack spread of cartilage, which has been verified by experiment. During the process of damage evolution, its extension direction and velocity varied constantly with the damage degree. The rolling load could cause larger stress and strain than sliding load. Strain values of the matrix initially increased and then decreased gradually with the increase of velocity, and velocity had a greater effect on matrix than fibers. Damage increased steadily before reaching 50%, sharply within 50 to 85%, and smoothly and slowly after 85%. The finding of the paper may help to understand the mechanical mechanism why the cracks in cartilage spread preferentially along the tangent direction of the fibers. Copyright © 2017 Elsevier B.V. All rights reserved.

Greater inadvertent muscle damage in direct anterior approach when compared with the direct superior approach for total hip arthroplasty.

PubMed

Amanatullah, D F; Masini, M A; Roger, D J; Pagnano, M W

2016-08-01

We wished to quantify the extent of soft-tissue damage sustained during minimally invasive total hip arthroplasty through the direct anterior (DA) and direct superior (DS) approaches. In eight cadavers, the DA approach was performed on one side, and the DS approach on the other, a single brand of uncemented hip prosthesis was implanted by two surgeons, considered expert in their surgical approaches. Subsequent reflection of the gluteus maximus allowed the extent of muscle and tendon damage to be measured and the percentage damage to each anatomical structure to be calculated. The DA approach caused substantially greater damage to the gluteus minimus muscle and tendon when compared with the DS approach (t-test, p = 0.049 and 0.003, respectively). The tensor fascia lata and rectus femoris muscles were damaged only in the DA approach. There was no difference in the amount of damage to the gluteus medius muscle and tendon, piriformis tendon, obturator internus tendon, obturator externus tendon or quadratus femoris muscle between approaches. The posterior soft-tissue releases of the DA approach damaged the gluteus minimus muscle and tendon, piriformis tendon and obturator internus tendon. The DS approach caused less soft-tissue damage than the DA approach. However the clinical relevance is unknown. Further clinical outcome studies, radiographic evaluation of component position, gait analyses and serum biomarker levels are necessary to evaluate and corroborate the safety and efficacy of the DS approach. Cite this article: Bone Joint J 2016;98-B1036-42. ©2016 The British Editorial Society of Bone & Joint Surgery.

Rate of Dehydration and Cumulative Desiccation Stress Interacted to Modulate Desiccation Tolerance of Recalcitrant Cocoa and Ginkgo Embryonic Tissues1

PubMed Central

Liang, Yongheng; Sun, Wendell Q.

2002-01-01

Rate of dehydration greatly affects desiccation tolerance of recalcitrant seeds. This effect is presumably related to two different stress vectors: direct mechanical or physical stress because of the loss of water and physicochemical damage of tissues as a result of metabolic alterations during drying. The present study proposed a new theoretic approach to represent these two types of stresses and investigated how seed tissues responded differently to two stress vectors, using the models of isolated cocoa (Theobroma cacao) and ginkgo (Ginkgo biloba) embryonic tissues dehydrated under various drying conditions. This approach used the differential change in axis water potential (ΔΨ/Δt) to quantify rate of dehydration and the intensity of direct physical stress experienced by embryonic tissues during desiccation. Physicochemical effect of drying was expressed by cumulative desiccation stress [∫\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\pagestyle{empty} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}{\\mathrm{_{o}^{t}}}\\end{equation*}\\end{document}f(ψ,t)], a function of both the rate and time of dehydration. Rapid dehydration increased the sensitivity of embryonic tissues to desiccation as indicated by high critical water contents, below which desiccation damage occurred. Cumulative desiccation stress increased sharply under slow drying conditions, which was also detrimental to embryonic tissues. This quantitative analysis of the stress-time-response relationship helps to understand the physiological basis for the existence of an optimal dehydration rate, with which maximum desiccation tolerance could be achieved. The established numerical analysis model will prove valuable for the design of experiments that aim to elucidate biochemical and physiological mechanisms of desiccation tolerance. PMID:11950981

From Physical Process to Economic Cost - Integrated Approaches of Landslide Risk Assessment

NASA Astrophysics Data System (ADS)

Klose, M.; Damm, B.

2014-12-01

The nature of landslides is complex in many respects, with landslide hazard and impact being dependent on a variety of factors. This obviously requires an integrated assessment for fundamental understanding of landslide risk. Integrated risk assessment, according to the approach presented in this contribution, implies combining prediction of future landslide occurrence with analysis of landslide impact in the past. A critical step for assessing landslide risk in integrated perspective is to analyze what types of landslide damage affected people and property in which way and how people contributed and responded to these damage types. In integrated risk assessment, the focus is on systematic identification and monetization of landslide damage, and analytical tools that allow deriving economic costs from physical landslide processes are at the heart of this approach. The broad spectrum of landslide types and process mechanisms as well as nonlinearity between landslide magnitude, damage intensity, and direct costs are some main factors explaining recent challenges in risk assessment. The two prevailing approaches for assessing the impact of landslides in economic terms are cost survey (ex-post) and risk analysis (ex-ante). Both approaches are able to complement each other, but yet a combination of them has not been realized so far. It is common practice today to derive landslide risk without considering landslide process-based cause-effect relationships, since integrated concepts or new modeling tools expanding conventional methods are still widely missing. The approach introduced in this contribution is based on a systematic framework that combines cost survey and GIS-based tools for hazard or cost modeling with methods to assess interactions between land use practices and landslides in historical perspective. Fundamental understanding of landslide risk also requires knowledge about the economic and fiscal relevance of landslide losses, wherefore analysis of their impact on public budgets is a further component of this approach. In integrated risk assessment, combination of methods plays an important role, with the objective of collecting and integrating complex data sets on landslide risk.

Hydrocephalus

MedlinePlus

... support and help with the care of a child with hydrocephalus who has serious brain damage. ... such as meningitis or encephalitis Intellectual impairment Nerve damage (decrease in movement, sensation, function) Physical disabilities

Apparent Explosion Moments from Rg Waves Recorded on SPE: Implications for the Late-Time Damage Source Model

NASA Astrophysics Data System (ADS)

Patton, H. J.; Larmat, C. S.; Rougier, E.

2016-12-01

Seismic moments for chemical shots making up Phase I of the Source Physics Experiments (SPE) are estimated from 6 Hz Rg waves under the assumption that the shots are pure explosions. These apparent explosion moments are compared to moments determined using the Reduced Displacement Potential (RDP) method applied to free field data. LIDAR/photogrammetry observations, strong ground motions on the free surface near ground zero, and moment tensor inversion results are evidence in support of the fourth shot SPE-4P being essentially a pure explosion. The apparent moment for SPE-4P is 9 × 1010 Nm in good agreement with the RDP moment 8 × 1010 Nm. In stark contrast, apparent moments for the first three shots are three to four times smaller than RDP moments. Data show that spallation occurred on these shots, as well as permanent deformations detected with ground-based LIDAR. As such, the source medium suffered late-time damage. The late-time damage source model predicts destructive interference between Rg waves radiated by explosion and damage sources, which reduces amplitudes and explains why apparent moments are smaller than RDP moments based on compressional energy emitted directly from the source. SPE-5 was conducted at roughly the same yield-scaled burial depth as SPE-2 and -3, but with five times the yield. As such, the damage source model predicts less reduction of apparent moment. At this writing, preliminary results from Rg interferometry and RDP moments confirm this prediction. SPE-6 is scheduled for the fall of 2016, and it should have the strongest damage source of all SPE shots. The damage model predicts that the polarity of Rg waves could be reversed. Realization of this prediction will be strong confirmation of the late-time damage source model. This abstract has a Los Alamos National Laboratory Unlimited Release Number LA-UR-16-25709.

[Physical and chemical emergencies in dermatology].

PubMed

Malisiewicz, B; Meissner, M; Kaufmann, R; Valesky, E

2018-05-01

Physical and chemical emergencies are often caused by household or work accidents. Regardless of the medical field and outside specialized clinics, the physician may be confronted with the situation for first or secondary care. The identification of the causing agent and a rapid assessment of the extent and severity of the tissue damage are essential to initiate early transfer to a specialized burn clinic. Grade 2b tissue damage is usually surgically treated. Smaller and superficial injuries can often be conservatively treated. Even supposedly safe and over-the-counter medicines can also lead to serious tissue damage.

Leith Creek, Scotland County, North Carolina, Detailed Project Report. Revised.

DTIC Science & Technology

1977-07-01

34Effect of the Plan on Environ- " ment" included loss of veqetation, tei.porary erosion and siltation, and better drained soils for a very narrow strip...tangible damages. Tangible damages are those subject to monetary evaluation and include: physical damages or losses to property and improvements...emergency costs for flood damage prevention; and business, 0 financial, and wage losses in and adjacent to flood areas. Intangible damages are not

DIRECT-ACTING, DNA-DAMAGING AS (III)-METHYLATED SPECIES: IMPLICATIONS FOR A CARCINOGENIC MECHANISM OF ACTION OF ARSENICALS

EPA Science Inventory

Direct-acting, DNA-damaging As (III)-methylated species: implications for a carcinogenic . mechanism of action of arsenicals

Inorganic arsenic (iAs, arsenite and arsenate) has been thought to act as a carcinogen without reacting directly with DNA; neither iAs nor the As(...

Computer synthesis of high resolution electron micrographs

NASA Technical Reports Server (NTRS)

Nathan, R.

1976-01-01

Specimen damage, spherical aberration, low contrast and noisy sensors combine to prevent direct atomic viewing in a conventional electron microscope. The paper describes two methods for obtaining ultra-high resolution in biological specimens under the electron microscope. The first method assumes the physical limits of the electron objective lens and uses a series of dark field images of biological crystals to obtain direct information on the phases of the Fourier diffraction maxima; this information is used in an appropriate computer to synthesize a large aperture lens for a 1-A resolution. The second method assumes there is sufficient amplitude scatter from images recorded in focus which can be utilized with a sensitive densitometer and computer contrast stretching to yield fine structure image details. Cancer virus characterization is discussed as an illustrative example. Numerous photographs supplement the text.

High-Throughput Sequencing Reveals Drastic Changes in Fungal Communities in the Phyllosphere of Norway Spruce (Picea abies) Following Invasion of the Spruce Bud Scale (Physokermes piceae).

PubMed

Menkis, Audrius; Marčiulynas, Adas; Gedminas, Artūras; Lynikienė, Jūratė; Povilaitienė, Aistė

2015-11-01

The aim of this study was to assess the diversity and composition of fungal communities in damaged and undamaged shoots of Norway spruce (Picea abies) following recent invasion of the spruce bud scale (Physokermes piceae) in Lithuania. Sampling was done in July 2013 and included 50 random lateral shoots from ten random trees in each of five visually undamaged and five damaged 40-50-year-old pure stands of P. abies. DNA was isolated from 500 individual shoots, subjected to amplification of the internal transcribed spacer of fungal ribosomal DNA (ITS rDNA), barcoded and sequenced. Clustering of 149,426 high-quality sequences resulted in 1193 non-singleton contigs of which 1039 (87.1 %) were fungal. In total, there were 893 fungal taxa in damaged shoots and 608 taxa in undamaged shoots (p < 0.0001). Furthermore, 431 (41.5 %) fungal taxa were exclusively in damaged shoots, 146 (14.0 %) were exclusively in undamaged shoots, and 462 (44.5 %) were common to both types of samples. Correspondence analysis showed that study sites representing damaged and undamaged shoots were separated from each other, indicating that in these fungal communities, these were largely different and, therefore, heavily affected by P. piceae. In conclusion, the results demonstrated that invasive alien tree pests may have a profound effect on fungal mycobiota associated with the phyllosphere of P. abies, and therefore, in addition to their direct negative effect owing physical damage of the tissue, they may also indirectly determine health, sustainability and, ultimately, distribution of the forest tree species.

Bottom-up modeling of damage in heterogeneous quasi-brittle solids

NASA Astrophysics Data System (ADS)

Rinaldi, Antonio

2013-03-01

The theoretical modeling of multisite cracking in quasi-brittle materials is a complex damage problem, hard to model with traditional methods of fracture mechanics due to its multiscale nature and to strain localization induced by microcracks interaction. Macroscale "effective" elastic models can be conveniently applied if a suitable Helmholtz free energy function is identified for a given material scenario. Del Piero and Truskinovsky (Continuum Mech Thermodyn 21:141-171, 2009), among other authors, investigated macroscale continuum solutions capable of matching—in a top-down view—the phenomenology of the damage process for quasi-brittle materials regardless of the microstructure. On the contrary, this paper features a physically based solution method that starts from the direct consideration of the microscale properties and, in a bottom-up view, recovers a continuum elastic description. This procedure is illustrated for a simple one-dimensional problem of this type, a bar modeled stretched by an axial displacement, where the bar is modeled as a 2D random lattice of decohesive spring elements of finite strength. The (microscale) data from simulations are used to identify the "exact" (macro-) damage parameter and to build up the (macro-) Helmholtz function for the equivalent elastic model, bridging the macroscale approach by Del Piero and Truskinovsky. The elastic approach, coupled with microstructural knowledge, becomes a more powerful tool to reproduce a broad class of macroscopic material responses by changing the convexity-concavity of the Helmholtz energy. The analysis points out that mean-field statistics are appropriate prior to damage localization but max-field statistics are better suited in the softening regime up to failure, where microstrain fluctuation needs to be incorporated in the continuum model. This observation is of consequence to revise mean-field damage models from literature and to calibrate Nth gradient continuum models.

Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

PubMed Central

Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

2014-01-01

Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

Cryopreservation of human blood for alkaline and Fpg-modified comet assay.

PubMed

Pu, Xinzhu; Wang, Zemin; Klaunig, James E

2016-01-01

The Comet assay is a reproducible and sensitive assay for the detection of DNA damage in eukaryotic cells and tissues. Incorporation of lesion specific, oxidative DNA damage repair enzymes (for example, Fpg, OGG1 and EndoIII) in the standard alkaline Comet assay procedure allows for the detection and measurement of oxidative DNA damage. The Comet assay using white blood cells (WBC) has proven useful in monitoring DNA damage from environmental agents in humans. However, it is often impractical to performance Comet assay immediately after blood sampling. Thus, storage of blood sample is required. In this study, we developed and tested a simple storage method for very small amount of whole blood for standard and Fpg-modified modified Comet assay. Whole blood was stored in RPMI 1640 media containing 10% FBS, 10% DMSO and 1 mM deferoxamine at a sample to media ratio of 1:50. Samples were stored at -20 °C and -80 °C for 1, 7, 14 and 28 days. Isolated lymphocytes from the same subjects were also stored under the same conditions for comparison. Direct DNA strand breakage and oxidative DNA damage in WBC and lymphocytes were analyzed using standard and Fpg-modified alkaline Comet assay and compared with freshly analyzed samples. No significant changes in either direct DNA strand breakage or oxidative DNA damage was seen in WBC and lymphocytes stored at -20 °C for 1 and 7 days compared to fresh samples. However, significant increases in both direct and oxidative DNA damage were seen in samples stored at -20 °C for 14 and 28 days. No changes in direct and oxidative DNA damage were observed in WBC and lymphocytes stored at -80 °C for up to 28 days. These results identified the proper storage conditions for storing whole blood or isolated lymphocytes to evaluate direct and oxidative DNA damage using standard and Fpg-modified alkaline Comet assay.

Runoff inundation hazard cartography

NASA Astrophysics Data System (ADS)

Pineux, N.; Degré, A.

2012-04-01

Between 1998 and 2004, Europe suffered from more than hundred major inundations, responsible for some 700 deaths, for the moving of about half a million of people and the economic losses of at least 25 billions Euros covered by the insurance policies. Within this context, EU launched the 2007/60/CE directive. The inundations are natural phenomenon. They cannot be avoided. Nevertheless this directive permits to better evaluate the risks and to coordinate the management measures taken at member states level. In most countries, inundation maps only include rivers' overflowing. In Wallonia, overland flows and mudflows also cause huge damages, and must be included in the flood hazard map. Indeed, the cleaning operations for a village can lead to an estimated cost of 11 000 €. Average construction cost of retention dams to control off-site damage caused by floods and muddy flows was valued at 380 000€, and yearly dredging costs associated with these retention ponds at 15 000€. For a small city for which a study was done in a more specific way (Gembloux), the mean annual cost for the damages that can generate the runoff is about 20 000€. This cost consists of the physical damages caused to the real estate and movable properties of the residents as well as the emergency operations of the firemen and the city. On top of damages to public infrastructure (clogging of trenches, silting up of retention ponds) and to private property by muddy flows, runoff generates a significant loss of arable land. Yet, the soil resource is not an unlimited commodity. Moreover, sediments' transfer to watercourses alters their physical and chemical quality. And that is not to mention the increased psychological stress for people. But to map overland flood and mud flow hazard is a real challenge. This poster will present the methodology used to in Wallonia. The methodology is based on 3 project rainfalls: 25, 50 and 100 years return period (consistency with the cartography of the overflowing hazard map), with a rain duration set at 1h. The arable lands are considered as bare, except for the permanent meadows. The worst situation is envisaged, the hydrologic effect of the soil cover in the farming area being variable from a year to another according to the vegetative development and to the cultural operations. The peak discharge is chosen as the more critic parameter because it synthesizes the watershed propensity to stream, its size, and its flow network. The cartographic representation is done in a linear way along the concentrated runoff axes. Whereas this first approach at regional scale includes uncertainties, the aim of this map is currently to prompt consideration of the runoff inundation hazard during the design of urban development projects.

Physical exercise prevents short and long-term deficits on aversive and recognition memory and attenuates brain oxidative damage induced by maternal deprivation.

PubMed

Neves, Ben-Hur; Menezes, Jefferson; Souza, Mauren Assis; Mello-Carpes, Pâmela B

2015-12-01

It is known from previous research that physical exercise prevents long-term memory deficits induced by maternal deprivation in rats. But we could not assume similar effects of physical exercise on short-term memory, as short- and long-term memories are known to result from some different memory consolidation processes. Here we demonstrated that, in addition to long-term memory deficit, the short-term memory deficit resultant from maternal deprivation in object recognition and aversive memory tasks is also prevented by physical exercise. Additionally, one of the mechanisms by which the physical exercise influences the memory processes involves its effects attenuating the oxidative damage in the maternal deprived rats' hippocampus and prefrontal cortex.

Effects of reactive oxygen species and interplay of antioxidants during physical exercise in skeletal muscles.

PubMed

Thirupathi, Anand; Pinho, Ricardo A

2018-05-01

A large number of researches have led to a substantial growth of knowledge about exercise and oxidative stress. Initial investigations reported that physical exercise generates free radical-mediated damages to cells; however, in recent years, studies have shown that regular exercise can upregulate endogenous antioxidants and reduce oxidative damage. Yet, strenuous exercise perturbs the antioxidant system by increasing the reactive oxygen species (ROS) content. These alterations in the cellular environment seem to occur in an exercise type-dependent manner. The source of ROS generation during exercise is debatable, but now it is well established that both contracting and relaxing skeletal muscles generate reactive oxygen species and reactive nitrogen species. In particular, exercises of higher intensity and longer duration can cause oxidative damage to lipids, proteins, and nucleotides in myocytes. In this review, we summarize the ROS effects and interplay of antioxidants in skeletal muscle during physical exercise. Additionally, we discuss how ROS-mediated signaling influences physical exercise in antioxidant system.

Apoptosis: Focus on sea urchin development.

PubMed

Agnello, Maria; Roccheri, Maria Carmela

2010-03-01

It has been proposed that the apoptosis is an essential requirement for the evolution of all animals, in fact the apoptotic program is highly conserved from nematodes to mammals. Throughout development, apoptosis is employed by multicellular organisms to eliminate damaged or unnecessary cells. Here, we will discuss both developmental programmed cell death (PCD) under normal conditions and stress induced apoptosis, in sea urchin embryos. Sea urchin represent an excellent model system for studying embryogenesis and cellular processes involved in metamorphosis. PCD plays an essential role in sculpting and remodelling the embryos and larvae undergoing metamorphosis. Moreover, this marine organism directly interacts with its environment, and is susceptible to effects of several aquatic contaminants. Apoptosis can be adopted as a defence mechanism against any environmental chemical, physical and mechanical stress, for removing irreversibly damaged cells. This review, while not comprehensive in its reporting, aims to provide an overview of current knowledge on mechanisms to regulate physiological and the induced apoptotic program in sea urchin embryos.

Aftershock collapse vulnerability assessment of reinforced concrete frame structures

USGS Publications Warehouse

Raghunandan, Meera; Liel, Abbie B.; Luco, Nicolas

2015-01-01

In a seismically active region, structures may be subjected to multiple earthquakes, due to mainshock–aftershock phenomena or other sequences, leaving no time for repair or retrofit between the events. This study quantifies the aftershock vulnerability of four modern ductile reinforced concrete (RC) framed buildings in California by conducting incremental dynamic analysis of nonlinear MDOF analytical models. Based on the nonlinear dynamic analysis results, collapse and damage fragility curves are generated for intact and damaged buildings. If the building is not severely damaged in the mainshock, its collapse capacity is unaffected in the aftershock. However, if the building is extensively damaged in the mainshock, there is a significant reduction in its collapse capacity in the aftershock. For example, if an RC frame experiences 4% or more interstory drift in the mainshock, the median capacity to resist aftershock shaking is reduced by about 40%. The study also evaluates the effectiveness of different measures of physical damage observed in the mainshock-damaged buildings for predicting the reduction in collapse capacity of the damaged building in subsequent aftershocks. These physical damage indicators for the building are chosen such that they quantify the qualitative red tagging (unsafe for occupation) criteria employed in post-earthquake evaluation of RC frames. The results indicated that damage indicators related to the drift experienced by the damaged building best predicted the reduced aftershock collapse capacities for these ductile structures.

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5-18 eV) electron interactions with DNA.

PubMed

Rezaee, Mohammad; Hunting, Darel J; Sanche, Léon

2014-07-01

The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Absorbed dose and stopping cross section for the Auger electrons of 5-18 eV emitted by(125)I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure-response curves for induction of DNA strand breaks. For a single decay of(125)I within DNA, the Auger electrons of 5-18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm(3) volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide.

Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies.

PubMed

Cloyd, Raymond A

2015-04-09

Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems.

Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain.

PubMed

Mattsson, Karin; Johnson, Elyse V; Malmendal, Anders; Linse, Sara; Hansson, Lars-Anders; Cedervall, Tommy

2017-09-13

The tremendous increases in production of plastic materials has led to an accumulation of plastic pollution worldwide. Many studies have addressed the physical effects of large-sized plastics on organisms, whereas few have focused on plastic nanoparticles, despite their distinct chemical, physical and mechanical properties. Hence our understanding of their effects on ecosystem function, behaviour and metabolism of organisms remains elusive. Here we demonstrate that plastic nanoparticles reduce survival of aquatic zooplankton and penetrate the blood-to-brain barrier in fish and cause behavioural disorders. Hence, for the first time, we uncover direct interactions between plastic nanoparticles and brain tissue, which is the likely mechanism behind the observed behavioural disorders in the top consumer. In a broader perspective, our findings demonstrate that plastic nanoparticles are transferred up through a food chain, enter the brain of the top consumer and affect its behaviour, thereby severely disrupting the function of natural ecosystems.

Adsorption of cadmium by activated carbon cloth: influence of surface oxidation and solution pH.

PubMed

Rangel-Mendez, J R; Streat, M

2002-03-01

The surface of activated carbon cloth (ACC), based on polyacrylonitrile fibre as a precursor, was oxidised using nitric acid, ozone and electrochemical oxidation to enhance cadmium ion exchange capacity. Modified adsorbents were physically and chemically characterised by pH titration, direct titration, X-ray photoelectron spectroscopy, elemental analysis, surface area and porosimetry, and scanning electron microscopy. BET surface area decreased after oxidation, however, the total ion exchange capacity increased by a factor of approximately 3.5 compared to the commercial as-received ACC. A very significant increase in cadmium uptake, by a factor of 13, was observed for the electrochemically oxidised ACC. Equilibrium sorption isotherms were determined at pH 4, 5 and 6 and these showed that cadmium uptake increased with increasing pH. There was clear evidence of physical damage to ozone-oxidised fibre, however, acid and electrochemically oxidised samples were completely stable.

Biphasic dose responses in biology, toxicology and medicine: accounting for their generalizability and quantitative features.

PubMed

Calabrese, Edward J

2013-11-01

The most common quantitative feature of the hormetic-biphasic dose response is its modest stimulatory response which at maximum is only 30-60% greater than control values, an observation that is consistently independent of biological model, level of organization (i.e., cell, organ or individual), endpoint measured, chemical/physical agent studied, or mechanism. This quantitative feature suggests an underlying "upstream" mechanism common across biological systems, therefore basic and general. Hormetic dose response relationships represent an estimate of the peak performance of integrative biological processes that are allometrically based. Hormetic responses reflect both direct stimulatory or overcompensation responses to damage induced by relatively low doses of chemical or physical agents. The integration of the hormetic dose response within an allometric framework provides, for the first time, an explanation for both the generality and the quantitative features of the hormetic dose response. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ecology of Fungus Gnats (Bradysia spp.) in Greenhouse Production Systems Associated with Disease-Interactions and Alternative Management Strategies

PubMed Central

Cloyd, Raymond A.

2015-01-01

Fungus gnats (Bradysia spp.) are major insect pests of greenhouse-grown horticultural crops mainly due to the direct feeding damage caused by the larvae, and the ability of larvae to transmit certain soil-borne plant pathogens. Currently, insecticides and biological control agents are being used successively to deal with fungus gnat populations in greenhouse production systems. However, these strategies may only be effective as long as greenhouse producers also implement alternative management strategies such as cultural, physical, and sanitation. This includes elimination of algae, and plant and growing medium debris; placing physical barriers onto the growing medium surface; and using materials that repel fungus gnat adults. This article describes the disease-interactions associated with fungus gnats and foliar and soil-borne diseases, and the alternative management strategies that should be considered by greenhouse producers in order to alleviate problems with fungus gnats in greenhouse production systems. PMID:26463188

Vibration fatigue using modal decomposition

NASA Astrophysics Data System (ADS)

Mršnik, Matjaž; Slavič, Janko; Boltežar, Miha

2018-01-01

Vibration-fatigue analysis deals with the material fatigue of flexible structures operating close to natural frequencies. Based on the uniaxial stress response, calculated in the frequency domain, the high-cycle fatigue model using the S-N curve material data and the Palmgren-Miner hypothesis of damage accumulation is applied. The multiaxial criterion is used to obtain the equivalent uniaxial stress response followed by the spectral moment approach to the cycle-amplitude probability density estimation. The vibration-fatigue analysis relates the fatigue analysis in the frequency domain to the structural dynamics. However, once the stress response within a node is obtained, the physical model of the structure dictating that response is discarded and does not propagate through the fatigue-analysis procedure. The structural model can be used to evaluate how specific dynamic properties (e.g., damping, modal shapes) affect the damage intensity. A new approach based on modal decomposition is presented in this research that directly links the fatigue-damage intensity with the dynamic properties of the system. It thus offers a valuable insight into how different modes of vibration contribute to the total damage to the material. A numerical study was performed showing good agreement between results obtained using the newly presented approach with those obtained using the classical method, especially with regards to the distribution of damage intensity and critical point location. The presented approach also offers orders of magnitude faster calculation in comparison with the conventional procedure. Furthermore, it can be applied in a straightforward way to strain experimental modal analysis results, taking advantage of experimentally measured strains.

Representing ductile damage with the dual domain material point method

DOE PAGES

Long, C. C.; Zhang, D. Z.; Bronkhorst, C. A.; ...

2015-12-14

In this study, we incorporate a ductile damage material model into a computational framework based on the Dual Domain Material Point (DDMP) method. As an example, simulations of a flyer plate experiment involving ductile void growth and material failure are performed. The results are compared with experiments performed on high purity tantalum. We also compare the numerical results obtained from the DDMP method with those obtained from the traditional Material Point Method (MPM). Effects of an overstress model, artificial viscosity, and physical viscosity are investigated. Our results show that a physical bulk viscosity and overstress model are important in thismore » impact and failure problem, while physical shear viscosity and artificial shock viscosity have negligible effects. A simple numerical procedure with guaranteed convergence is introduced to solve for the equilibrium plastic state from the ductile damage model.« less

Radiation-induced effects on the mechanical properties of natural ZrSiO4: double cascade-overlap damage accumulation

NASA Astrophysics Data System (ADS)

Beirau, Tobias; Nix, William D.; Pöllmann, Herbert; Ewing, Rodney C.

2018-05-01

Several different models are known to describe the structure-dependent radiation-induced damage accumulation process in materials (e.g. Gibbons Proc IEEE 60:1062-1096, 1972; Weber Nuc Instr Met Phys Res B 166-167:98-106, 2000). In the literature, two different models of damage accumulation due to α-decay events in natural ZrSiO4 (zircon) have been described. The direct impact damage accumulation model is based on amorphization occurring directly within the collision cascade. However, the double cascade-overlap damage accumulation model predicts that amorphization will only occur due to the overlap of disordered domains within the cascade. By analyzing the dose-dependent evolution of mechanical properties (i.e., Poisson's ratios, compliance constants, elastic modulus, and hardness) as a measure of the increasing amorphization, we provide support for the double cascade-overlap damage accumulation model. We found no evidence to support the direct impact damage accumulation model. Additionally, the amount of radiation damage could be related to an anisotropic-to-isotropic transition of the Poisson's ratio for stress along and perpendicular to the four-fold c-axis and of the related compliance constants of natural U- and Th-bearing zircon. The isotropification occurs in the dose range between 3.1 × and 6.3 × 1018 α-decays/g.

Radiation-induced effects on the mechanical properties of natural ZrSiO4: double cascade-overlap damage accumulation

NASA Astrophysics Data System (ADS)

Beirau, Tobias; Nix, William D.; Pöllmann, Herbert; Ewing, Rodney C.

2017-11-01

Several different models are known to describe the structure-dependent radiation-induced damage accumulation process in materials (e.g. Gibbons Proc IEEE 60:1062-1096, 1972; Weber Nuc Instr Met Phys Res B 166-167:98-106, 2000). In the literature, two different models of damage accumulation due to α-decay events in natural ZrSiO4 (zircon) have been described. The direct impact damage accumulation model is based on amorphization occurring directly within the collision cascade. However, the double cascade-overlap damage accumulation model predicts that amorphization will only occur due to the overlap of disordered domains within the cascade. By analyzing the dose-dependent evolution of mechanical properties (i.e., Poisson's ratios, compliance constants, elastic modulus, and hardness) as a measure of the increasing amorphization, we provide support for the double cascade-overlap damage accumulation model. We found no evidence to support the direct impact damage accumulation model. Additionally, the amount of radiation damage could be related to an anisotropic-to-isotropic transition of the Poisson's ratio for stress along and perpendicular to the four-fold c-axis and of the related compliance constants of natural U- and Th-bearing zircon. The isotropification occurs in the dose range between 3.1 × and 6.3 × 1018 α-decays/g.

Mixed martial arts induces significant fatigue and muscle damage up to 24 hours post-combat.

PubMed

Ghoul, Nihel; Tabben, Montassar; Miarka, Bianca; Tourny, Claire; Chamari, Karim; Coquart, Jeremy

2017-06-22

This study investigates the physiological/physical responses to a simulated mixed martial arts (MMA) competition over 24 hr. Twelve fighters performed a simulated MMA competition, consisting of three 5-min MMA matches. Physiological/physical data were assessed before (Trest), directly after round 1 (Trd1), round 2 (Trd2) and round 3 (Trd3), and then 30-min (Trecovery30min) and/or 24-hr (Trecovery24h) post-competition. Heart rate (HR), rating of perceived exertion (RPE) and blood lactate concentration ([La]) were assessed at Trest, Trd1, Trd2 and Trd3. Biological data were collected at Trest, Trd3, Trecovery30min and Trecovery24h. Physical tests were performed at Trest, Trecovery30min and Trecovery24h. HR, RPE and [La] were high during competition. Leukocytes, hemoglobin, total protein and glycemia were increased at Trd3 compared with all other time points (p<0.05). Cortisol was increased at Trd3 compared with Trest and Trecovery24h (p<0.05). Testosterone was higher at Trd3 and Trecovery30min than Trest (p<0.001). Higher values of uric acid were noted during recovery periods (p<0.001). Lactate dehydrogenase was lower at Trest compared with Trd3, Trecovery30min and Trecovery24h (p<0.05). Countermovement jump was higher at Trest than Trecovery30min (p=0.020). Consequently, MMA is a high-intensity intermittent combat sport that induces significant fatigue and muscle damage, both of which are still present 24-hr post-competition.

Biomaterials and scaffolds in reparative medicine

NASA Technical Reports Server (NTRS)

Chaikof, Elliot L.; Matthew, Howard; Kohn, Joachim; Mikos, Antonios G.; Prestwich, Glenn D.; Yip, Christopher M.; McIntire, L. V. (Principal Investigator)

2002-01-01

Most approaches currently pursued or contemplated within the framework of reparative medicine, including cell-based therapies, artificial organs, and engineered living tissues, are dependent on our ability to synthesize or otherwise generate novel materials, fabricate or assemble materials into appropriate 2-D and 3-D forms, and precisely tailor material-related physical and biological properties so as to achieve a desired clinical response. This paper summarizes the scientific and technological opportunities within the fields of biomaterials science and molecular engineering that will likely establish new enabling technologies for cellular and molecular therapies directed at the repair, replacement, or reconstruction of diseased or damaged organs and tissues.

Quantitative risk assessment using empirical vulnerability functions from debris flow event reconstruction

NASA Astrophysics Data System (ADS)

Luna, Byron Quan; Blahut, Jan; Camera, Corrado; van Westen, Cees; Sterlacchini, Simone; Apuani, Tiziana; Akbas, Sami

2010-05-01

For a quantitative risk assessment framework it is essential to assess not only the hazardous process itself but to perform an analysis of their consequences. This quantitative assessment should include the expected monetary losses as the product of the probability of occurrence of a hazard with a given magnitude and its vulnerability. A quantifiable integrated approach of both hazard and risk is becoming a required practice in risk reduction management. Dynamic run-out models for debris flows are able to calculate physical outputs (extension, depths, velocities, impact pressures) and to determine the zones where the elements at risk could suffer an impact. These results are then applied for vulnerability and risk calculations. The risk assessment has been conducted in the Valtellina Valley, a typical Italian alpine valley lying in northern Italy (Lombardy Region). On 13th July 2008, after more than two days of intense rainfall, several debris and mud flows were released in the central part of valley between Morbegno and Berbenno. One of the largest debris flows occurred in Selvetta. The debris flow event was reconstructed after extensive field work and interviews with local inhabitants and civil protection teams. Also inside the Valtellina valley, between the 22nd and the 23rd of May 1983, two debris flows happened in Tresenda (Teglio municipality), causing casualties and considerable economic damages. On the same location, during the 26th of November 2002, another debris flow occurred that caused significant damage. For the quantification of a new scenario, the outcome results obtained from the event of Selvetta were applied in Tresenda. The Selvetta and Tresenda event were modelled with the FLO2D program. FLO2D is an Eulerian formulation with a finite differences numerical scheme that requires the specification of an input hydrograph. The internal stresses are isotropic and the basal shear stresses are calculated using a quadratic model. The significance of calculated values of pressure and velocity were investigated in terms of the resulting damage to the affected buildings. The physical damage was quantified for each affected structure within the context of physical vulnerability, which is defined as the ratio between the monetary loss and the reconstruction value. Two different empirical vulnerability curves were obtained, which are functions of debris flow velocity and pressure, respectively. Prospective economic direct losses were estimated.

A Generalized Orthotropic Elasto-Plastic Material Model for Impact Analysis

NASA Astrophysics Data System (ADS)

Hoffarth, Canio

Composite materials are now beginning to provide uses hitherto reserved for metals in structural systems such as airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. These structural systems are often subjected to impact loads and there is a pressing need for accurate prediction of deformation, damage and failure. There are numerous material models that have been developed to analyze the dynamic impact response of polymer matrix composites. However, there are key features that are missing in those models that prevent them from providing accurate predictive capabilities. In this dissertation, a general purpose orthotropic elasto-plastic computational constitutive material model has been developed to predict the response of composites subjected to high velocity impacts. The constitutive model is divided into three components - deformation model, damage model and failure model, with failure to be added at a later date. The deformation model generalizes the Tsai-Wu failure criteria and extends it using a strain-hardening-based orthotropic yield function with a non-associative flow rule. A strain equivalent formulation is utilized in the damage model that permits plastic and damage calculations to be uncoupled and capture the nonlinear unloading and local softening of the stress-strain response. A diagonal damage tensor is defined to account for the directionally dependent variation of damage. However, in composites it has been found that loading in one direction can lead to damage in multiple coordinate directions. To account for this phenomena, the terms in the damage matrix are semi-coupled such that the damage in a particular coordinate direction is a function of the stresses and plastic strains in all of the coordinate directions. The overall framework is driven by experimental tabulated temperature and rate-dependent stress-strain data as well as data that characterizes the damage matrix and failure. The developed theory has been implemented in a commercial explicit finite element analysis code, LS-DYNARTM, as MAT213. Several verification and validation tests using a commonly available carbon-fiber composite, Toyobo's T800/F3900, have been carried and the results show that the theory and implementation are efficient, robust and accurate.

Postexercise Dietary Protein Strategies to Maximize Skeletal Muscle Repair and Remodeling in Masters Endurance Athletes: A Review.

PubMed

Doering, Thomas M; Reaburn, Peter R; Phillips, Stuart M; Jenkins, David G

2016-04-01

Participation rates of masters athletes in endurance events such as long-distance triathlon and running continue to increase. Given the physical and metabolic demands of endurance training, recovery practices influence the quality of successive training sessions and, consequently, adaptations to training. Research has suggested that, after muscle-damaging endurance exercise, masters athletes experience slower recovery rates in comparison with younger, similarly trained athletes. Given that these discrepancies in recovery rates are not observed after non-muscle-damaging exercise, it is suggested that masters athletes have impairments of the protein remodeling mechanisms within skeletal muscle. The importance of postexercise protein feeding for endurance athletes is increasingly being acknowledged, and its role in creating a positive net muscle protein balance postexercise is well known. The potential benefits of postexercise protein feeding include elevating muscle protein synthesis and satellite cell activity for muscle repair and remodeling, as well as facilitating muscle glycogen resynthesis. Despite extensive investigation into age-related anabolic resistance in sedentary aging populations, little is known about how anabolic resistance affects postexercise muscle protein synthesis and thus muscle remodeling in aging athletes. Despite evidence suggesting that physical training can attenuate but not eliminate age-related anabolic resistance, masters athletes are currently recommended to consume the same postexercise dietary protein dose (approximately 20 g or 0.25 g/kg/meal) as younger athletes. Given the slower recovery rates of masters athletes after muscle-damaging exercise, which may be due to impaired muscle remodeling mechanisms, masters athletes may benefit from higher doses of postexercise dietary protein, with particular attention directed to the leucine content of the postexercise bolus.

ATM Protein Physically and Functionally Interacts with Proliferating Cell Nuclear Antigen to Regulate DNA Synthesis*

PubMed Central

Gamper, Armin M.; Choi, Serah; Matsumoto, Yoshihiro; Banerjee, Dibyendu; Tomkinson, Alan E.; Bakkenist, Christopher J.

2012-01-01

Ataxia telangiectasia (A-T) is a pleiotropic disease, with a characteristic hypersensitivity to ionizing radiation that is caused by biallelic mutations in A-T mutated (ATM), a gene encoding a protein kinase critical for the induction of cellular responses to DNA damage, particularly to DNA double strand breaks. A long known characteristic of A-T cells is their ability to synthesize DNA even in the presence of ionizing radiation-induced DNA damage, a phenomenon termed radioresistant DNA synthesis. We previously reported that ATM kinase inhibition, but not ATM protein disruption, blocks sister chromatid exchange following DNA damage. We now show that ATM kinase inhibition, but not ATM protein disruption, also inhibits DNA synthesis. Investigating a potential physical interaction of ATM with the DNA replication machinery, we found that ATM co-precipitates with proliferating cell nuclear antigen (PCNA) from cellular extracts. Using bacterially purified ATM truncation mutants and in vitro translated PCNA, we showed that the interaction is direct and mediated by the C terminus of ATM. Indeed, a 20-amino acid region close to the kinase domain is sufficient for strong binding to PCNA. This binding is specific to ATM, because the homologous regions of other PIKK members, including the closely related kinase A-T and Rad3-related (ATR), did not bind PCNA. ATM was found to bind two regions in PCNA. To examine the functional significance of the interaction between ATM and PCNA, we tested the ability of ATM to stimulate DNA synthesis by DNA polymerase δ, which is implicated in both DNA replication and DNA repair processes. ATM was observed to stimulate DNA polymerase activity in a PCNA-dependent manner. PMID:22362778

BioSentinel: Mission Development of a Radiation Biosensor to Gauge DNA Damage and Repair Beyond Low Earth Orbit on a 6U Nanosatellite

NASA Technical Reports Server (NTRS)

Sanchez, Hugo; Lewis, Brian; Hanel, Robert

2015-01-01

We are designing and developing a 6U (10 x 22 x 34 cm; 14 kg) nanosatellite as a secondary payload to fly aboard NASAs Space Launch System (SLS) Exploration Mission (EM) 1, scheduled for launch in late 2017. For the first time in over forty years, direct experimental data from biological studies beyond low Earth orbit (LEO) will be obtained during BioSentinels 12- to 18-month mission. BioSentinel will measure the damage and repair of DNA in a biological organism and allow us to compare that to information from onboard physical radiation sensors. In order to understand the relative contributions of the space environments two dominant biological perturbations, reduced gravity and ionizing radiation, results from deep space will be directly compared to data obtained in LEO (on ISS) and on Earth. These data points will be available for validation of existing biological radiation damage and repair models, and for extrapolation to humans, to assist in mitigating risks during future long-term exploration missions beyond LEO. The BioSentinel Payload occupies 4U of the spacecraft and will utilize the monocellular eukaryotic organism Saccharomyces cerevisiae (yeast) to report DNA double-strand-break (DSB) events that result from ambient space radiation. DSB repair exhibits striking conservation of repair proteins from yeast to humans. Yeast was selected because of 1) its similarity to cells in higher organisms, 2) the well-established history of strains engineered to measure DSB repair, 3) its spaceflight heritage, and 4) the wealth of available ground and flight reference data. The S. cerevisiae flight strain will include engineered genetic defects to prevent growth and division until a radiation-induced DSB activates the yeasts DNA repair mechanisms. The triggered culture growth and metabolic activity directly indicate a DSB and its successful repair. The yeast will be carried in the dry state within the 1-atm PL container in 18 separate fluidics cards with each card having 16 independent culture microwells, with integral microchannels and filters to supply nutrients and reagents, confine the yeast to the wells, and enable optical measurement. The measurement subsystem will monitor each subgroup of culture wells continuously for several weeks, optically tracking DSB-triggered cell growth and metabolism. BioSentinel will also include physical radiation sensors based on the TimePix sensor, as implemented by JSCs RadWorks group, which record individual radiation events including estimates of their linear-energy-transfer (LET) values. Radiation-dose and LET data will be compared directly to the rate of DSB-and-repair events measured by the S. cerevisiae biosentinels.

Fatigue analysis and testing of wind turbine blades

NASA Astrophysics Data System (ADS)

Greaves, Peter Robert

This thesis focuses on fatigue analysis and testing of large, multi MW wind turbine blades. The blades are one of the most expensive components of a wind turbine, and their mass has cost implications for the hub, nacelle, tower and foundations of the turbine so it is important that they are not unnecessarily strong. Fatigue is often an important design driver, but fatigue of composites is poorly understood and so large safety factors are often applied to the loads. This has implications for the weight of the blade. Full scale fatigue testing of blades is required by the design standards, and provides manufacturers with confidence that the blade will be able to survive its service life. This testing is usually performed by resonating the blade in the flapwise and edgewise directions separately, but in service these two loads occur at the same time.. A fatigue testing method developed at Narec (the National Renewable Energy Centre) in the UK in which the flapwise and edgewise directions are excited simultaneously has been evaluated by comparing the Palmgren-Miner damage sum around the blade cross section after testing with the damage distribution caused by the service life. A method to obtain the resonant test configuration that will result in the optimum mode shapes for the flapwise and edgewise directions was then developed, and simulation software was designed to allow the blade test to be simulated so that realistic comparisons between the damage distributions after different test types could be obtained. During the course of this work the shortcomings with conventional fatigue analysis methods became apparent, and a novel method of fatigue analysis based on multi-continuum theory and the kinetic theory of fracture was developed. This method was benchmarked using physical test data from the OPTIDAT database and was applied to the analysis of a complete blade. A full scale fatigue test method based on this new analysis approach is also discussed..

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

Oxygen removal during pathogen inactivation with riboflavin and UV light preserves protein function in plasma for transfusion.

PubMed

Feys, H B; Van Aelst, B; Devreese, K; Devloo, R; Coene, J; Vandekerckhove, P; Compernolle, V

2014-05-01

Photochemical pathogen inactivation technologies (PCT) for individual transfusion products act by inhibition of replication through irreversibly damaging nucleic acids. Concern on the collateral impact of PCT on the blood component's integrity has caused reluctance to introduce this technology in routine practice. This work aims to uncover the mechanism of damage to plasma constituents by riboflavin pathogen reduction technology (RF-PRT). Activity and antigen of plasma components were determined following RF-PRT in the presence or absence of dissolved molecular oxygen. Employing ADAMTS13 as a sentinel molecule in plasma, our data show that its activity and antigen are reduced by 23 ± 8% and 29 ± 9% (n = 24), respectively, which corroborates with a mean decrease of 25% observed for other coagulation factors. Western blotting of ADAMTS13 shows decreased molecular integrity, with no obvious indication of additional proteolysis nor is riboflavin able to directly inhibit the enzyme. However, physical removal of dissolved oxygen prior to RF-PRT protects ADAMTS13 as well as FVIII and fibrinogen from damage, indicating a direct role for reactive oxygen species. Redox dye measurements indicate that superoxide anions are specifically generated during RF-PRT. Protein carbonyl content as a marker of disseminated irreversible biomolecular damage was significantly increased (3·1 ± 0·8 vs. 1·6 ± 0·5 nmol/mg protein) following RF-PRT, but not in the absence of dissolved molecular oxygen (1·8 ± 0·4 nmol/mg). RF-PRT of single plasma units generates reactive oxygen species that adversely affect biomolecular integrity of relevant plasma constituents, a side-effect, which can be bypassed by applying hypoxic conditions during the pathogen inactivation process. © 2013 International Society of Blood Transfusion.

ATM directs DNA damage responses and proteostasis via genetically separable pathways

PubMed Central

Lee, Ji-Hoon; Mand, Michael R.; Kao, Chung-Hsuan; Zhou, Yi; Ryu, Seung W.; Richards, Alicia L.; Coon, Joshua J.; Paull, Tanya T.

2018-01-01

The protein kinase ATM is a master regulator of the DNA damage response but also responds directly to oxidative stress. Loss of ATM causes Ataxia telangiectasia, a neurodegenerative disorder with pleiotropic symptoms that include cerebellar dysfunction, cancer, diabetes, and premature aging. Here, we genetically separated DNA damage activation of ATM from oxidative activation using separation-of-function mutations. We found that deficiency in ATM activation by Mre11-Rad50-Nbs1 and DNA double-strand breaks resulted in loss of cell viability, checkpoint activation, and DNA end resection in response to DNA damage. In contrast, loss of oxidative activation of ATM had minimal effects on DNA damage-related outcomes but blocked ATM-mediated initiation of checkpoint responses after oxidative stress and resulted in deficiencies in mitochondrial function and autophagy. In addition, expression of ATM lacking oxidative activation generates widespread protein aggregation. These results indicate a direct relationship between the mechanism of ATM activation and its effects on cellular metabolism and DNA damage responses in human cells and implicates ATM in the control of protein homeostasis. PMID:29317520

Detection of damage in welded structure using experimental modal data

NASA Astrophysics Data System (ADS)

Abu Husain, N.; Ouyang, H.

2011-07-01

A typical automotive structure could contain thousands of spot weld joints that contribute significantly to the vehicle's structural stiffness and dynamic characteristics. However, some of these joints may be imperfect or even absent during the manufacturing process and they are also highly susceptible to damage due to operational and environmental conditions during the vehicle lifetime. Therefore, early detection and estimation of damage are important so necessary actions can be taken to avoid further problems. Changes in physical parameters due to existence of damage in a structure often leads to alteration of vibration modes; thus demonstrating the dependency between the vibration characteristics and the physical properties of structures. A sensitivity-based model updating method, performed using a combination of MATLAB and NASTRAN, has been selected for the purpose of this work. The updating procedure is regarded as parameter identification which aims to bring the numerical prediction to be as closely as possible to the measured natural frequencies and mode shapes data of the damaged structure in order to identify the damage parameters (characterised by the reductions in the Young's modulus of the weld patches to indicate the loss of material/stiffness at the damage region).

Paraheliotropic leaf movement in Siratro as a protective mechanism against drought-induced damage to primary photosynthetic reactions: damage by excessive light and heat.

PubMed

Ludlow, M M; Björkman, O

1984-11-01

Damage to primary photosynthetic reactions by drought, excess light and heat in leaves of Macroptilium atropurpureum Dc. cv. Siratro was assessed by measurements of chlorophyll fluorescence emission kinetics at 77 K (-196°C). Paraheliotropic leaf movement protected waterstressed Siratro leaves from damage by excess light (photoinhibition), by heat, and by the interactive effects of excess light and high leaf temperatures. When the leaves were restrained to a horizontal position, photoinhibition occurred and the degree of photoinhibitory damage increased with the time of exposure to high levels of solar radiation. Severe inhibition was followed by leaf death, but leaves gradually recovered from moderate damage. This drought-induced photoinhibitory damage seemed more closely related to low leaf water potential than to low leaf conductance. Exposure to leaf temperatures above 42°C caused damage to the photosynthetic system even in the dark and leaves died at 48°C. Between 42 and 48°C the degree of heat damage increased with the time of exposure, but recovery from moderate heat damage occurred over several days. The threshold temperature for direct heat damage increased with the growth temperature regime, but was unaffected by water-stress history or by current leaf water status. No direct heat damage occurred below 42°C, but in water-stressed plants photoinhibition increased with increasing leaf temperature in the range 31-42°C and with increasing photon flux density up to full sunglight values. Thus, water stress evidently predisposes the photosynthetic system to photoinhibition and high leaf temperature exacerbates this photoinhibitory damage. It seems probable that, under the climatic conditions where Siratro occurs in nature, but in the absence of paraheliotropic leaf movement, photoinhibitory damage would occur more frequently during drought than would direct heat damage.

41 CFR 109-1.5113 - Loss, damage, or destruction of personal property in possession of designated contractors.

Code of Federal Regulations, 2010 CFR

2010-07-01

... designated contractors. (a) Designated contractors shall report any loss, damage, or destruction of personal... administrator; or loss, damage, or destruction of personal property not previously reported by the contractor... written reports. (c) Reports of physical inventory results and identified discrepancies shall be submitted...

41 CFR 109-1.5113 - Loss, damage, or destruction of personal property in possession of designated contractors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... designated contractors. (a) Designated contractors shall report any loss, damage, or destruction of personal... administrator; or loss, damage, or destruction of personal property not previously reported by the contractor... written reports. (c) Reports of physical inventory results and identified discrepancies shall be submitted...

Effects of electrocautery on transvenous lead insulation materials.

PubMed

Lim, Kiam-Khiang; Reddy, Shantanu; Desai, Shrojal; Smelley, Matthew; Kim, Susan S; Beshai, John F; Lin, Albert C; Burke, Martin C; Knight, Bradley P

2009-04-01

Insulation defects are a leading cause of transvenous lead failure. The purpose of this study was to determine the effects of electrocautery on transvenous lead insulation materials. A preparation was done to simulate dissection of a transvenous lead from tissues. Radiofrequency energy was delivered using a standard cautery blade at outputs of 10, 20, and 30 W, for 3 and 6 seconds, using parallel and perpendicular blade orientations on leads with outermost insulations of silicone rubber, polyurethane, and silicone-polyurethane copolymer. Damage to each lead segment was classified after visual and microscopic analysis. Significant insulation damage occurred to almost all polyurethane leads. Full insulation breaches were observed with 30 W regardless of application duration with a parallel direction and with all power outputs with a perpendicular direction. Thermal insulation damage to copolymer insulation was similar to that of the polyurethane leads. In contrast, there was no thermal damage to silicone leads, regardless of the power output and duration of power delivery. However, mechanical insulation damage was observed to all silicone leads when at least 20 W was applied in a direction perpendicular to the lead. Polyurethane (PU55D) and copolymer materials have low thermal stability and are highly susceptible to thermal damage during cautery. Implanting physicians should be aware of the lead insulation materials being used during implant procedures and their properties. The use of direct contact cautery on transvenous leads should be minimized to avoid damage to the lead, especially on leads with polyurethane or copolymer outer insulations.

Distinct contributions of adverse childhood experiences and resilience resources: a cohort analysis of adult physical and mental health.

PubMed

Logan-Greene, Patricia; Green, Sara; Nurius, Paula S; Longhi, Dario

2014-01-01

Although evidence is rapidly amassing as to the damaging potential of early life adversities on physical and mental health, as yet few investigations provide comparative snapshots of these patterns across adulthood. This population-based study addresses this gap, examining the relationship of adverse childhood experiences (ACEs) to physical and mental health within a representative sample (n = 19,333) of adults, comparing the prevalence and explanatory strength of ACEs among four birth cohorts spanning ages 18-79. This assessment accounts for demographic and socioeconomic factors, as well as both direct and moderating effects of resilience resources (social/emotional support, life satisfaction, and sleep quality). Findings demonstrate (1) increasing trends of reported ACEs across younger cohorts, including time period shifts such as more prevalent family incarceration, substance abuse, and divorce, (2) significant bivariate as well as independent associations of ACEs with poor health within every cohort, controlling for multiple covariates (increasing trends in older age for physical health), and (3) robust patterns wherein resilience resources moderated ACEs, indicating buffering pathways that sustained into old age. Theoretical and practice implications for health professionals are discussed.

Constitutive equations of a tensorial model for strain-induced damage of metals based on three invariants

NASA Astrophysics Data System (ADS)

Tutyshkin, Nikolai D.; Lofink, Paul; Müller, Wolfgang H.; Wille, Ralf; Stahn, Oliver

2017-01-01

On the basis of the physical concepts of void formation, nucleation, and growth, generalized constitutive equations are formulated for a tensorial model of plastic damage in metals based on three invariants. The multiplicative decomposition of the metric transformation tensor and a thermodynamically consistent formulation of constitutive relations leads to a symmetric second-order damage tensor with a clear physical meaning. Its first invariant determines the damage related to plastic dilatation of the material due to growth of the voids. The second invariant of the deviatoric damage tensor is related to the change in void shape. The third invariant of the deviatoric tensor describes the impact of the stress state on damage (Lode angle), including the effect of rotating the principal axes of the stress tensor (Lode angle change). The introduction of three measures with related physical meaning allows for the description of kinetic processes of strain-induced damage with an equivalent parameter in a three-dimensional vector space, including the critical condition of ductile failure. Calculations were performed by using experimentally determined material functions for plastic dilatation and deviatoric strain at the mesoscale, as well as three-dimensional graphs for plastic damage of steel DC01. The constitutive parameter was determined from tests in tension, compression, and shear by using scanning electron microscopy, which allowed to vary the Lode angle over the full range of its values [InlineEquation not available: see fulltext.]. In order to construct the three-dimensional plastic damage curve for a range of triaxiality parameters -1 ≤ ST ≤ 1 and of Lode angles [InlineEquation not available: see fulltext.], we used our own, as well as systematized published experimental data. A comparison of calculations shows a significant effect of the third invariant (Lode angle) on equivalent damage. The measure of plastic damage, based on three invariants, can be useful for assessing the quality of metal mesostructure produced during metal forming processes. In many processes of metal sheet forming the material experiences, a non-proportional loading accompanied by rotating the principal axes of the stress tensor and a corresponding change of Lode angle.

Synergistic Effects of Physical Aging and Damage on Long-Term Behavior of Polymer Matrix Composites

NASA Technical Reports Server (NTRS)

Brinson, L. Cate

1999-01-01

The research consisted of two major parts, first modeling and simulation of the combined effects of aging and damage on polymer composites and secondly an experimental phase examining composite response at elevated temperatures, again activating both aging and damage. For the simulation, a damage model for polymeric composite laminates operating at elevated temperatures was developed. Viscoelastic behavior of the material is accounted for via the correspondence principle and a variational approach is adopted to compute the temporal stresses within the laminate. Also, the effect of physical aging on ply level stress and on overall laminate behavior is included. An important feature of the model is that damage evolution predictions for viscoelastic laminates can be made. This allows us to track the mechanical response of the laminate up to large load levels though within the confines of linear viscoelastic constitutive behavior. An experimental investigation of microcracking and physical aging effects in polymer matrix composites was also pursued. The goal of the study was to assess the impact of aging on damage accumulation, in ten-ns of microcracking, and the impact of damage on aging and viscoelastic behavior. The testing was performed both at room and elevated temperatures on [+/- 45/903](sub s) and [02/903](sub s) laminates, both containing a set of 90 deg plies centrally located to facilitate investigation of microcracking. Edge replication and X-ray-radiography were utilized to quantify damage. Sequenced creep tests were performed to characterize viscoelastic and aging parameters. Results indicate that while the aging times studied have limited ]Influence on damage evolution, elevated temperature and viscoelastic effects have a profound effect on the damage mode seen. Some results are counterintuitive, including the lower strain to failure for elevated temperature tests and the catastrophic failure mode observed for the [+/- 45/9O3](sub s), specimens. The fracture toughness for transverse cracks increases with increasing temperature for both systems: transverse cracking was completely absent prior to failure in [+/- 45/903](sub s), and was suppressed for [02/903](sub s). No significant effect of damage on aging or viscoelastic parameters was observed.

Photoluminescence Study of Plasma-Induced Damage of GaInN Single Quantum Well

NASA Astrophysics Data System (ADS)

Izumi, Shouichiro; Minami, Masaki; Kamada, Michiru; Tatsumi, Tetsuya; Yamaguchi, Atsushi A.; Ishikawa, Kenji; Hori, Masaru; Tomiya, Shigetaka

2013-08-01

Plasma-induced damage (PID) due to Cl2/SiCl4/Ar plasma etching of the GaN capping layer (CAP)/GaInN single quantum well (SQW)/GaN structure was investigated by conventional photoluminescence (PL), transmission electron microscopy (TEM), and time-resolved and temperature-dependent photoluminescence (TRPL). SQW PL intensity remained constant initially, although plasma etching of the CAP layer proceeded, but when the etching thickness reached a certain amount (˜60 nm above the SQW), PL intensity started to decrease sharply. On the other hand, TEM observations show that the physical damage (structural damage) was limited to the topmost surface region. These findings can be explained by the results of TRPL studies, which revealed that there exist two different causes of PID. One is an increase in the number of nonradiative recombination centers, which mainly affects the PL intensity. The other is an increase in the quantum level fluctuation owing mainly to physical damage.

The SAFRR tsunami scenario-physical damage in California: Chapter E in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

USGS Publications Warehouse

Porter, Keith; Byers, William; Dykstra, David; Lim, Amy; Lynett, Patrick; Ratliff, Jaime; Scawthorn, Charles; Wein, Anne; Wilson, Rick

2013-01-01

his chapter attempts to depict a single realistic outcome of the SAFRR (Science Application for Risk Reduction) tsunami scenario in terms of physical damage to and recovery of various aspects of the built environment in California. As described elsewhere in this report, the tsunami is generated by a hypothetical magnitude 9.1 earthquake seaward of the Alaska Peninsula on the Semidi Sector of the Alaska–Aleutian Subduction Zone, 495 miles southwest of Anchorage, at 11:50 a.m. Pacific Daylight Time (PDT) on Thursday March 27, 2014, and arriving at the California coast between 4:00 and 5:40 p.m. (depending on location) the same day. Although other tsunamis could have locally greater impact, this source represents a substantial threat to the state as a whole. One purpose of this chapter is to help operators and users of coastal assets throughout California to develop emergency plans to respond to a real tsunami. Another is to identify ways that operators or owners of these assets can think through options for reducing damage before a future tsunami. A third is to inform the economic analyses for the SAFRR tsunami scenario. And a fourth is to identify research needs to better understand the possible consequences of a tsunami on these assets. The asset classes considered here include the following: Piers, cargo, buildings, and other assets at the Ports of Los Angeles and Long Beach Large vessels in the Ports of Los Angeles and Long Beach Marinas and small craft Coastal buildings Roads and roadway bridges Rail, railway bridges, and rolling stock Agriculture Fire following tsunami Each asset class is examined in a subsection of this chapter. In each subsection, we generally attempt to offer a historical review of damage. We characterize and quantify the assets exposed to loss and describe the modes of damage that have been observed in past tsunamis or are otherwise deemed likely to occur in the SAFRR tsunami scenario. Where practical, we offer a mathematical model of the damageability of assets exposed to loss. Then, applying the damageability model and the velocity, wave amplitude, and inundation models discussed in other SAFRR chapters we offer a single realistic depiction of damage. Other outcomes are of course possible for this hypothetical event. Where practical we estimate repair costs and estimate the duration required to restore the assets to their pre-tsunami condition. We identify opportunities to enhance the resiliency of the assets, either through making them less vulnerable to damage or able to recover more quickly in spite of the damage. Finally, we identify uncertainties in the modeling where research would improve our understanding of the underlying mechanisms of damage and loss or otherwise improve our ability to estimate the future impacts of tsunamis and inform risk-management decisions for tsunamis. However, it is certain that the kinds of damages discussed here have occurred in past tsunamis, even in developed nations, and in a sufficiently large event, will occur in California. Our uncertainties can operate in either direction, either leading to an overestimate of damage or an underestimate. Therefore, losses in an actual future tsunami could be greater than depicted here. Furthermore this evaluation is not intended to be an exhaustive depiction of what could happen in this or similar tsunamis. Other impacts could occur that are not presented here.

The economic costs of traffic accidents in Spain.

PubMed

Bastida, Julio López; Aguilar, Pedro Serrano; González, Beatriz Duque

2004-04-01

This study aimed to evaluate the economic impact of traffic accidents in Spain during 1997. The cost-of-illness method was used. Direct costs were divided into health services costs, insurance administration costs, and the costs of the material damages to the vehicles. Indirect costs were obtained through transformation of physical units into monetary units using the approach based on the human capital theory. The total cost of traffic accidents was 6,280.36 million euros, which amounts to 157.59 euros for each inhabitant in Spain and represents 1.35% of the gross national product. The total direct cost was 3,397.00 million euros, representing 54.1% of the total cost. The total indirect cost was 2,883.36 million euros, accounting for 45.9% of the total cost. The high socioeconomic cost of traffic accidents clearly indicates the need for the different administrations in Spain to collaborate in implementing preventive measures.

An implementation of discrete electron transport models for gold in the Geant4 simulation toolkit

NASA Astrophysics Data System (ADS)

Sakata, D.; Incerti, S.; Bordage, M. C.; Lampe, N.; Okada, S.; Emfietzoglou, D.; Kyriakou, I.; Murakami, K.; Sasaki, T.; Tran, H.; Guatelli, S.; Ivantchenko, V. N.

2016-12-01

Gold nanoparticle (GNP) boosted radiation therapy can enhance the biological effectiveness of radiation treatments by increasing the quantity of direct and indirect radiation-induced cellular damage. As the physical effects of GNP boosted radiotherapy occur across energy scales that descend down to 10 eV, Monte Carlo simulations require discrete physics models down to these very low energies in order to avoid underestimating the absorbed dose and secondary particle generation. Discrete physics models for electron transportation down to 10 eV have been implemented within the Geant4-DNA low energy extension of Geant4. Such models allow the investigation of GNP effects at the nanoscale. At low energies, the new models have better agreement with experimental data on the backscattering coefficient, and they show similar performance for transmission coefficient data as the Livermore and Penelope models already implemented in Geant4. These new models are applicable in simulations focussed towards estimating the relative biological effectiveness of radiation in GNP boosted radiotherapy applications with photon and electron radiation sources.

Hydrodynamic cavitation kills prostate cells and ablates benign prostatic hyperplasia tissue.

PubMed

Itah, Zeynep; Oral, Ozlem; Perk, Osman Yavuz; Sesen, Muhsincan; Demir, Ebru; Erbil, Secil; Dogan-Ekici, A Isin; Ekici, Sinan; Kosar, Ali; Gozuacik, Devrim

2013-11-01

Hydrodynamic cavitation is a physical phenomenon characterized by vaporization and bubble formation in liquids under low local pressures, and their implosion following their release to a higher pressure environment. Collapse of the bubbles releases high energy and may cause damage to exposed surfaces. We recently designed a set-up to exploit the destructive nature of hydrodynamic cavitation for biomedical purposes. We have previously shown that hydrodynamic cavitation could kill leukemia cells and erode kidney stones. In this study, we analyzed the effects of cavitation on prostate cells and benign prostatic hyperplasia (BPH) tissue. We showed that hydrodynamic cavitation could kill prostate cells in a pressure- and time-dependent manner. Cavitation did not lead to programmed cell death, i.e. classical apoptosis or autophagy activation. Following the application of cavitation, we observed no prominent DNA damage and cells did not arrest in the cell cycle. Hence, we concluded that cavitation forces directly damaged the cells, leading to their pulverization. Upon application to BPH tissues from patients, cavitation could lead to a significant level of tissue destruction. Therefore similar to ultrasonic cavitation, we propose that hydrodynamic cavitation has the potential to be exploited and developed as an approach for the ablation of aberrant pathological tissues, including BPH.

Skeletal muscle damage and impaired regeneration due to LPL-mediated lipotoxicity

PubMed Central

Tamilarasan, K P; Temmel, H; Das, S K; Al Zoughbi, W; Schauer, S; Vesely, P W; Hoefler, G

2012-01-01

According to the concept of lipotoxicity, ectopic accumulation of lipids in non-adipose tissue induces pathological changes. The most prominent effects are seen in fatty liver disease, lipid cardiomyopathy, non-insulin-dependent diabetes mellitus, insulin resistance and skeletal muscle myopathy. We used the MCK(m)-hLPL mouse distinguished by skeletal and cardiac muscle-specific human lipoprotein lipase (hLPL) overexpression to investigate effects of lipid overload in skeletal muscle. We were intrigued to find that ectopic lipid accumulation induced proteasomal activity, apoptosis and skeletal muscle damage. In line with these findings we observed reduced Musculus gastrocnemius and Musculus quadriceps mass in transgenic animals, accompanied by severely impaired physical endurance. We suggest that muscle loss was aggravated by impaired muscle regeneration as evidenced by reduced cross-sectional area of regenerating myofibers after cardiotoxin-induced injury in MCK(m)-hLPL mice. Similarly, an almost complete loss of myogenic potential was observed in C2C12 murine myoblasts upon overexpression of LPL. Our findings directly link lipid overload to muscle damage, impaired regeneration and loss of performance. These findings support the concept of lipotoxicity and are a further step to explain pathological effects seen in muscle of obese patients, patients with the metabolic syndrome and patients with cancer-associated cachexia. PMID:22825472

Modeling variability in air pollution-related health damages from individual airport emissions.

PubMed

Penn, Stefani L; Boone, Scott T; Harvey, Brian C; Heiger-Bernays, Wendy; Tripodis, Yorghos; Arunachalam, Sarav; Levy, Jonathan I

2017-07-01

In this study, we modeled concentrations of fine particulate matter (PM 2.5 ) and ozone (O 3 ) attributable to precursor emissions from individual airports in the United States, developing airport-specific health damage functions (deaths per 1000t of precursor emissions) and physically-interpretable regression models to explain variability in these functions. We applied the Community Multiscale Air Quality model using the Decoupled Direct Method to isolate PM 2.5 - or O 3 -related contributions from precursor pollutants emitted by 66 individual airports. We linked airport- and pollutant-specific concentrations with population data and literature-based concentration-response functions to create health damage functions. Deaths per 1000t of primary PM 2.5 emissions ranged from 3 to 160 across airports, with variability explained by population patterns within 500km of the airport. Deaths per 1000t of precursors for secondary PM 2.5 varied across airports from 0.1 to 2.7 for NOx, 0.06 to 2.9 for SO 2 , and 0.06 to 11 for VOCs, with variability explained by population patterns and ambient concentrations influencing particle formation. Deaths per 1000t of O 3 precursors ranged from -0.004 to 1.0 for NOx and 0.03 to 1.5 for VOCs, with strong seasonality and influence of ambient concentrations. Our findings reinforce the importance of location- and source-specific health damage functions in design of health-maximizing emissions control policies. Copyright © 2017 Elsevier Inc. All rights reserved.

[Physical activity: positive impact on brain plasticity].

PubMed

Achiron, Anat; Kalron, Alon

2008-03-01

The central nervous system has a unique capability of plasticity that enables a single neuron or a group of neurons to undergo functional and constructional changes that are important to learning processes and for compensation of brain damage. The current review aims to summarize recent data related to the effects of physical activity on brain plasticity. In the last decade it was reported that physical activity can affect and manipulate neuronal connections, synaptic activity and adaptation to new neuronal environment following brain injury. One of the most significant neurotrophic factors that is critical for synaptic re-organization and is influenced by physical activity is brain-derived neurotrophic factor (BDNF). The frequency of physical activity and the intensity of exercises are of importance to brain remodeling, support neuronal survival and positively affect rehabilitation therapy. Physical activity should be employed as a tool to improve neural function in healthy subjects and in patients suffering from neurological damage.

Dynamics and Adaptive Control for Stability Recovery of Damaged Aircraft

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Krishnakumar, Kalmanje; Kaneshige, John; Nespeca, Pascal

2006-01-01

This paper presents a recent study of a damaged generic transport model as part of a NASA research project to investigate adaptive control methods for stability recovery of damaged aircraft operating in off-nominal flight conditions under damage and or failures. Aerodynamic modeling of damage effects is performed using an aerodynamic code to assess changes in the stability and control derivatives of a generic transport aircraft. Certain types of damage such as damage to one of the wings or horizontal stabilizers can cause the aircraft to become asymmetric, thus resulting in a coupling between the longitudinal and lateral motions. Flight dynamics for a general asymmetric aircraft is derived to account for changes in the center of gravity that can compromise the stability of the damaged aircraft. An iterative trim analysis for the translational motion is developed to refine the trim procedure by accounting for the effects of the control surface deflection. A hybrid direct-indirect neural network, adaptive flight control is proposed as an adaptive law for stabilizing the rotational motion of the damaged aircraft. The indirect adaptation is designed to estimate the plant dynamics of the damaged aircraft in conjunction with the direct adaptation that computes the control augmentation. Two approaches are presented 1) an adaptive law derived from the Lyapunov stability theory to ensure that the signals are bounded, and 2) a recursive least-square method for parameter identification. A hardware-in-the-loop simulation is conducted and demonstrates the effectiveness of the direct neural network adaptive flight control in the stability recovery of the damaged aircraft. A preliminary simulation of the hybrid adaptive flight control has been performed and initial data have shown the effectiveness of the proposed hybrid approach. Future work will include further investigations and high-fidelity simulations of the proposed hybrid adaptive Bight control approach.

Analysis and Characterization of Damage and Failure Utilizing a Generalized Composite Material Model Suitable for Use in Impact Problems

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Khaled, Bilal; Hoffarth, Canio; Rajan, Subramaniam; Blankenhorn, Gunther

2016-01-01

A material model which incorporates several key capabilities which have been identified by the aerospace community as lacking in state-of-the art composite impact models is under development. In particular, a next generation composite impact material model, jointly developed by the FAA and NASA, is being implemented into the commercial transient dynamic finite element code LS-DYNA. The material model, which incorporates plasticity, damage, and failure, utilizes experimentally based tabulated input to define the evolution of plasticity and damage and the initiation of failure as opposed to specifying discrete input parameters (such as modulus and strength). The plasticity portion of the orthotropic, three-dimensional, macroscopic composite constitutive model is based on an extension of the Tsai-Wu composite failure model into a generalized yield function with a non-associative flow rule. For the damage model, a strain equivalent formulation is utilized to allow for the uncoupling of the deformation and damage analyses. In the damage model, a semi-coupled approach is employed where the overall damage in a particular coordinate direction is assumed to be a multiplicative combination of the damage in that direction resulting from the applied loads in the various coordinate directions. Due to the fact that the plasticity and damage models are uncoupled, test procedures and methods to both characterize the damage model and to covert the material stress-strain curves from the true (damaged) stress space to the effective (undamaged) stress space have been developed. A methodology has been developed to input the experimentally determined composite failure surface in a tabulated manner. An analytical approach is then utilized to track how close the current stress state is to the failure surface.

Influence of drill helical direction on exit damage development in drilling carbon fiber reinforced plastic

NASA Astrophysics Data System (ADS)

Bai, Y.; Jia, Z. Y.; Wang, F. J.; Fu, R.; Guo, H. B.; Cheng, D.; Zhang, B. Y.

2017-06-01

Drilling is inevitable for CFRP components’ assembling process in the aviation industry. The exit damage frequently occurs and affects the load carrying capacity of components. Consequently, it is of great urgency to enhance drilling exit quality on CFRP components. The article aims to guide the reasonable choice of drill helical direction and effectively reduce exit damage. Exit observation experiments are carried out with left-hand helical, right-hand helical and straight one-shot drill drilling T800S CFRP laminates separately. The development rules of exit damage and delamination factor curves are obtained. Combined with loading conditions and fracture modes of push-out burrs, and thrust force curves, the influence of drill helical direction on exit damage development is derived. It is found that the main fracture modes for left-hand helical, right-hand helical, and straight one-shot drill are mode I, extrusive fracture, mode III respectively. Among them, mode III has the least effect on exit damage development. Meanwhile, the changing rate of thrust force is relative slow for right-hand helical and straight one-shot drill in the thrust force increasing phase of stage II, which is disadvantaged for exit damage development. Therefore, straight one-shot drill’s exit quality is the best.

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms of hOGG1 (Ser326Cys).

PubMed

Soares, Jorge Pinto; Silva, Ana Inês; Silva, Amélia M; Almeida, Vanessa; Teixeira, João Paulo; Matos, Manuela; Gaivão, Isabel; Mota, Maria Paula

2015-12-01

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism. Copyright © 2015 John Wiley & Sons, Ltd.

Simulation of Micron-Sized Debris Populations in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Xu, Y.-L.; Hyde, J. L.; Prior, T.; Matney, Mark

2010-01-01

The update of ORDEM2000, the NASA Orbital Debris Engineering Model, to its new version ORDEM2010, is nearly complete. As a part of the ORDEM upgrade, this paper addresses the simulation of micro-debris (greater than 10 m and smaller than 1 mm in size) populations in low Earth orbit. The principal data used in the modeling of the micron-sized debris populations are in-situ hypervelocity impact records, accumulated in post-flight damage surveys on the space-exposed surfaces of returned spacecrafts. The development of the micro-debris model populations follows the general approach to deriving other ORDEM2010-required input populations for various components and types of debris. This paper describes the key elements and major steps in the statistical inference of the ORDEM2010 micro-debris populations. A crucial step is the construction of a degradation/ejecta source model to provide prior information on the micron-sized objects (such as orbital and object-size distributions). Another critical step is to link model populations with data, which is rather involved. It demands detailed information on area-time/directionality for all the space-exposed elements of a shuttle orbiter and damage laws, which relate impact damage with the physical properties of a projectile and impact conditions such as impact angle and velocity. Also needed are model-predicted debris fluxes as a function of object size and impact velocity from all possible directions. In spite of the very limited quantity of the available shuttle impact data, the population-derivation process is satisfactorily stable. Final modeling results obtained from shuttle window and radiator impact data are reasonably convergent and consistent, especially for the debris populations with object-size thresholds at 10 and 100 m.

Simulation of Micron-Sized Debris Populations in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Xu, Y.-L.; Matney, M.; Liou, J.-C.; Hyde, J. L.; Prior, T. G.

2010-01-01

The update of ORDEM2000, the NASA Orbital Debris Engineering Model, to its new version . ORDEM2010, is nearly complete. As a part of the ORDEM upgrade, this paper addresses the simulation of micro-debris (greater than 10 micron and smaller than 1 mm in size) populations in low Earth orbit. The principal data used in the modeling of the micron-sized debris populations are in-situ hypervelocity impact records, accumulated in post-flight damage surveys on the space-exposed surfaces of returned spacecrafts. The development of the micro-debris model populations follows the general approach to deriving other ORDEM2010-required input populations for various components and types of debris. This paper describes the key elements and major steps in the statistical inference of the ORDEM2010 micro-debris populations. A crucial step is the construction of a degradation/ejecta source model to provide prior information on the micron-sized objects (such as orbital and object-size distributions). Another critical step is to link model populations with data, which is rather involved. It demands detailed information on area-time/directionality for all the space-exposed elements of a shuttle orbiter and damage laws, which relate impact damage with the physical properties of a projectile and impact conditions such as impact angle and velocity. Also needed are model-predicted debris fluxes as a function of object size and impact velocity from all possible directions. In spite of the very limited quantity of the available shuttle impact data, the population-derivation process is satisfactorily stable. Final modeling results obtained from shuttle window and radiator impact data are reasonably convergent and consistent, especially for the debris populations with object-size thresholds at 10 and 100 micron.

Damage Accumulation in SiC/SiC Composites with 3D Architectures

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.; Yun, Hee-Mann; DiCarlo, James A.

2003-01-01

The formation and propagation of multiple matrix cracks in relatively dense ceramic matrix composites when subjected to increasing tensile stress is necessary for high strength and tough composites. However, the occurrence of matrix cracks at low stresses may limit the usefulness of some non-oxide composite systems when subjected to oxidizing environments for long times at stresses sufficient to cause matrix cracking. For SiC fiber-reinforced composites with two-dimensional woven architectures and chemically vapor infiltrated (CVI) SiC matrix and melt-infiltrated (MI) Si/SiC matrix composites, the matrix cracking behavior has been fairly well characterized for different fiber-types and woven architectures. It was found that the occurrence, degree, and growth of matrix cracks depends on the material properties of the composite constituents as well as other physical properties of the composite or architecture, e.g., matrix porosity and size of the fiber bundle. In this study, matrix cracking in SiC fiber reinforced, melt-infiltrated SiC composites with a 3D orthogonal architecture was determined for specimens tested in tension at room temperature. Acoustic emission (AE) was used to monitor the matrix cracking activity, which was later confirmed by microscopic examination of specimens that had failed. The determination of the exact location of AE demonstrated that initial cracking occurred in the matrix rich regions when a large z-direction fiber bundle was used. For specimens with large z-direction fiber tows, the earliest matrix cracking could occur at half the stress for standard 2D woven composites with similar constituents. Damage accumulation in 3D architecture composites will be compared to damage accumulation in 2D architecture composites and discussed with respect to modeling composite stress-strain behavior and use of these composites at elevated temperatures.

A new record of longicorn beetle, Acanthophorus rugiceps, from India as a root borer on physic nut, Jatropha curcas, with a description of life stages, biology, and seasonal dynamics.

PubMed

Prabhakar, Mathyam; Prasad, Y G; Rao, G R; Venkateswarlu, B

2012-01-01

Longicorn beetle, Acanthophorus rugiceps Gahan (Coleoptera: Cerambycidae), is reported for the first time as a confirmed host on physic nut, Jatropha curcas L. (Malpighiales: Euphorbiaceae), from India, causing extensive damage to roots. Plants of three years age and above were prone to attack by this pest. In a six year study beginning in 2005, about 11.3 percent of plants in a 16.25 acre physic nut plantation were severely damaged by A. rugiceps. Life stages of A. rugiceps, including egg, larvae, pupae, and adult, are described with a note on their habitat, biology, and behavior. Strategies to manage this pest on physic nut are discussed.

Abortion Services and Military Medical Facilities

DTIC Science & Technology

2010-07-08

long -lasting physical health damage to the mother would result if the pregnancy were carried to term when so determined by two physicians. Nor are...with regard to the “severe and long -lasting physical health damage to the mother that would result if the pregnancy were carried to term when so...in uniform by as much as 50%.42 Under the Administration’s long - term defense spending plans, 5,600 civilian medical personnel will be cut from the

Thermomechanical fatigue life prediction for several solders

NASA Astrophysics Data System (ADS)

Wen, Shengmin

Since solder connections operate at high homologous temperature, solders are high temperature materials. This feature makes their mechanical behavior and fatigue phenomena unique. Based on experimental findings, a physical damage mechanism is introduced for solders. The mechanism views the damage process as a series of independent local damage events characterized by the failure of individual grains, while the structural damage is the eventual percolation result of such local events. Fine's dislocation energy density concept and Mura's microcrack initiation theory are adopted to derive the fatigue formula for an individual grain. A physical damage metric is introduced to describe the material with damage. A unified creep and plasticity constitutive model is adopted to simulate the mechanical behavior of solders. The model is cast into a continuum damage mechanics framework to simulate material with damage. The model gives good agreement with the experimental results of 96.5Pb-3.5Sn and 96.5Sn-3.5Ag solders under uniaxial strain-controlled cyclic loading. The model is convenient for implementation into commercial computational packages. Also presented is a fatigue theory with its failure criterion for solders based on physical damage mechanism. By introducing grain orientation into the fatigue formula, an m-N curve (m is Schmid factor) at constant loading condition is suggested for fatigue of grains with different orientations. A solder structure is defined as fatigued when the damage metric reaches a critical threshold, since at this threshold the failed grains may form a cluster and percolate through the structure according to percolation theory. Fatigue data of 96.5Pb-3.5Sn solder bulk specimens under various uniaxial tension tests were analyzed. Results show that the theory gives consistent predictions under broad conditions, while inelastic strain theory does not. The theory is anisotropic with no size limitation to its application, which could be suitable for anisotropic small-scale (micron or nano scale) solder joints. More importantly, the theory is materials science based so that the parameters of the fatigue formula can be worked out by testing of bulk specimens while the formula can be applicable to small-scale structures. The theory suggests metallurgical control in the manufacturing process to optimize the fatigue life of solder structures.

75 FR 33821 - Recovery Policy RP9524.10; Direct Disaster-Related Damage to Eligible Facilities

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

... DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency [Docket ID FEMA-2010-0024] Recovery Policy RP9524.10; Direct Disaster-Related Damage to Eligible Facilities AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice of availability; request for comments. SUMMARY: The Federal Emergency...

Virtual earthquake engineering laboratory with physics-based degrading materials on parallel computers

NASA Astrophysics Data System (ADS)

Cho, In Ho

For the last few decades, we have obtained tremendous insight into underlying microscopic mechanisms of degrading quasi-brittle materials from persistent and near-saintly efforts in laboratories, and at the same time we have seen unprecedented evolution in computational technology such as massively parallel computers. Thus, time is ripe to embark on a novel approach to settle unanswered questions, especially for the earthquake engineering community, by harmoniously combining the microphysics mechanisms with advanced parallel computing technology. To begin with, it should be stressed that we placed a great deal of emphasis on preserving clear meaning and physical counterparts of all the microscopic material models proposed herein, since it is directly tied to the belief that by doing so, the more physical mechanisms we incorporate, the better prediction we can obtain. We departed from reviewing representative microscopic analysis methodologies, selecting out "fixed-type" multidirectional smeared crack model as the base framework for nonlinear quasi-brittle materials, since it is widely believed to best retain the physical nature of actual cracks. Microscopic stress functions are proposed by integrating well-received existing models to update normal stresses on the crack surfaces (three orthogonal surfaces are allowed to initiate herein) under cyclic loading. Unlike the normal stress update, special attention had to be paid to the shear stress update on the crack surfaces, due primarily to the well-known pathological nature of the fixed-type smeared crack model---spurious large stress transfer over the open crack under nonproportional loading. In hopes of exploiting physical mechanism to resolve this deleterious nature of the fixed crack model, a tribology-inspired three-dimensional (3d) interlocking mechanism has been proposed. Following the main trend of tribology (i.e., the science and engineering of interacting surfaces), we introduced the base fabric of solid particle-soft matrix to explain realistic interlocking over rough crack surfaces, and the adopted Gaussian distribution feeds random particle sizes to the entire domain. Validation against a well-documented rough crack experiment reveals promising accuracy of the proposed 3d interlocking model. A consumed energy-based damage model has been proposed for the weak correlation between the normal and shear stresses on the crack surfaces, and also for describing the nature of irrecoverable damage. Since the evaluation of the consumed energy is directly linked to the microscopic deformation, which can be efficiently tracked on the crack surfaces, the proposed damage model is believed to provide a more physical interpretation than existing damage mechanics, which fundamentally stem from mathematical derivation with few physical counterparts. Another novel point of the present work lies in the topological transition-based "smart" steel bar model, notably with evolving compressive buckling length. We presented a systematic framework of information flow between the key ingredients of composite materials (i.e., steel bar and its surrounding concrete elements). The smart steel model suggested can incorporate smooth transition during reversal loading, tensile rupture, early buckling after reversal from excessive tensile loading, and even compressive buckling. Especially, the buckling length is made to evolve according to the damage states of the surrounding elements of each bar, while all other dominant models leave the length unchanged. What lies behind all the aforementioned novel attempts is, of course, the problem-optimized parallel platform. In fact, the parallel computing in our field has been restricted to monotonic shock or blast loading with explicit algorithm which is characteristically feasible to be parallelized. In the present study, efficient parallelization strategies for the highly demanding implicit nonlinear finite element analysis (FEA) program for real-scale reinforced concrete (RC) structures under cyclic loading are proposed. Quantitative comparison of state-of-the-art parallel strategies, in terms of factorization, had been carried out, leading to the problem-optimized solver, which is successfully embracing the penalty method and banded nature. Particularly, the penalty method employed imparts considerable smoothness to the global response, which yields a practical superiority of the parallel triangular system solver over other advanced solvers such as parallel preconditioned conjugate gradient method. Other salient issues on parallelization are also addressed. The parallel platform established offers unprecedented access to simulations of real-scale structures, giving new understanding about the physics-based mechanisms adopted and probabilistic randomness at the entire system level. Particularly, the platform enables bold simulations of real-scale RC structures exposed to cyclic loading---H-shaped wall system and 4-story T-shaped wall system. The simulations show the desired capability of accurate prediction of global force-displacement responses, postpeak softening behavior, and compressive buckling of longitudinal steel bars. It is fascinating to see that intrinsic randomness of the 3d interlocking model appears to cause "localized" damage of the real-scale structures, which is consistent with reported observations in different fields such as granular media. Equipped with accuracy, stability and scalability as demonstrated so far, the parallel platform is believed to serve as a fertile ground for the introducing of further physical mechanisms into various research fields as well as the earthquake engineering community. In the near future, it can be further expanded to run in concert with reliable FEA programs such as FRAME3d or OPENSEES. Following the central notion of "multiscale" analysis technique, actual infrastructures exposed to extreme natural hazard can be successfully tackled by this next generation analysis tool---the harmonious union of the parallel platform and a general FEA program. At the same time, any type of experiments can be easily conducted by this "virtual laboratory."

Optical monitoring of spinal cord subcellular damage after acute spinal cord injury

NASA Astrophysics Data System (ADS)

Shadgan, Babak; Manouchehri, Neda; So, Kitty; Shortt, Katelyn; Fong, Allan; Streijger, Femke; Macnab, Andrew; Kwon, Brian K.

2018-02-01

Introduction: Sudden physical trauma to the spinal cord results in acute spinal cord injury (SCI), leading to spinal cord (SC) tissue destruction, acute inflammation, increased SC intraparenchymal pressure, and tissue ischemia, hypoxia, and cellular necrosis. The ability to monitor SC tissue viability at subcellular level, using a real-time noninvasive method, would be extremely valuable to clinicians for estimating acute SCI damage, and adjusting and monitoring treatment in the intensive care setting. This study examined the feasibility and sensitivity of a custommade near infrared spectroscopy (NIRS) sensor to monitor the oxidation state of SC mitochondrial cytochrome aa3 (CCO), which reflects the subcellular damage of SC tissue in an animal model of SCI. Methods: Six anesthetized Yorkshire pigs were studied using a custom-made multi-wavelength NIRS system with a miniaturized optical sensor applied directly on the surgically exposed SC at T9. The oxidation states of SC tissue hemoglobin and CCO were monitored before, during and after acute SCI, and during mean arterial pressure alterations. Results: Non-invasive NIRS monitoring reflected changes in SC tissue CCO, simultaneous but independent of changes in hemoglobin saturation following acute SCI. A consistent decrease in SC tissue CCO chromophore concentration (-1.98 +/- 2.1 ab, p<0.05) was observed following SCI, indicating progressive SC cellular damage at the injury site. Elevation of mean arterial pressure can reduce SC tissue damage as suggested by different researchers and observed by significant increase in SC tissue CCO concentration (1.51 +/- 1.7 ab, p<0.05) in this study. Conclusions: This pilot study indicates that a novel miniaturized multi-wave NIRS sensor has the potential to monitor post-SCI changes of SC cytochrome aa3 oxygenation state in real time. Further development of this method may offer new options for improved SCI care.

Marine Food Protection in Testicular Damages Caused by Diabetes Mellitus.

PubMed

Caiaffo, Vitor; Ribeiro de Oliveira, Belisa Duarte; de Sa, Fabricio Bezerra; Neto, Joaqvim Evencio; da Silva Junior, Voldemiro Amaro

2017-01-01

Diabetes Mellitus (DM) is a chronic hyperglycemic condition with major health concern on a global scale. DM is a heterogeneous metabolic disorder stemming from defective insulin secretion and/or resistance to action of insulin. Diabetes is recognized cause of male sexual dysfunction and affects reproductive function in humans and animal models, including the endocrine control of spermatogenesis, erectile dysfunction and ejaculation disorder. Testicular disorder is characteristically marked by reductions of testicle weight, sperm count and motility, as well as changes in the morphology of the seminiferous epithelium. Altered testosterone level is another characteristic of diabetic animals. Studies have demonstrated that DM increases apoptosis in germ cells and lead to the interruption of spermatogenesis, mainly by exerting an influence on Bcl-2 protein and cysteinedependent aspartate-directed proteases. DM also increases oxidative stress in testicular cells and excessive production of radical oxygen species has been demonstrated. Several strategies can be used as means of prevention and/or treatment for diverse types of damage to testicles by DM such as regular physical exercise, stress reduction and food intake of substances with antioxidant potential. A hypoglycemic and antioxidant potential diet, in particular, the seafood, can be a valuable instrument of guard against damage caused by DM, both the systemic level as testicular level. The objective of this review is to summarize evidences that study the antioxidant, anti-inflammatory and anti-apoptosis role of seafood in testicles morphology damages induced by diabetes mellitus. The seafood plays an antioxidant, anti-inflammatory and anti-apoptosis role in testicles morphology damages induced by diabetes mellitus. This relation seems to be associated with Omega-3 and carotenoids (astaxanthin) levels. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Plant defence as a complex and changing phenotype throughout ontogeny

PubMed Central

Ochoa-López, Sofía; Villamil, Nora; Zedillo-Avelleyra, Paulina; Boege, Karina

2015-01-01

Background and Aims Ontogenetic changes in anti-herbivore defences are common and result from variation in resource availability and herbivore damage throughout plant development. However, little is known about the simultaneous changes of multiple defences across the entire development of plants, and how such changes affect plant damage in the field. The aim of this study was to assess if changes in the major types of plant resistance and tolerance can explain natural herbivore damage throughout plant ontogeny. Methods An assessment was made of how six defensive traits, including physical, chemical and biotic resistance, simultaneously change across the major transitions of plant development, from seedlings to reproductive stages of Turnera velutina growing in the greenhouse. In addition, an experiment was performed to assess how plant tolerance to artificial damage to leaves changed throughout ontogeny. Finally, leaf damage by herbivores was evaluated in a natural population. Key Results The observed ontogenetic trajectories of all defences were significantly different, sometimes showing opposite directions of change. Whereas trichome density, leaf toughness, extrafloral nectary abundance and nectar production increased, hydrogen cyanide and compensatory responses decreased throughout plant development, from seedlings to reproductive plants. Only water content was higher at the intermediate juvenile ontogenetic stages. Surveys in a natural population over 3 years showed that herbivores consumed more tissue from juvenile plants than from younger seedlings or older reproductive plants. This is consistent with the fact that juvenile plants were the least defended stage. Conclusions The results suggest that defensive trajectories are a mixed result of predictions by the Optimal Defence Theory and the Growth–Differentiation Balance Hypothesis. The study emphasizes the importance of incorporating multiple defences and plant ontogeny into further studies for a more comprehensive understanding of plant defence evolution. PMID:26220657

A novel single-cell method provides direct evidence of persistent DNA damage in senescent cells and aged mammalian tissues.

PubMed

Galbiati, Alessandro; Beauséjour, Christian; d'Adda di Fagagna, Fabrizio

2017-04-01

The DNA damage response (DDR) arrests cell cycle progression until DNA lesions, like DNA double-strand breaks (DSBs), are repaired. The presence of DSBs in cells is usually detected by indirect techniques that rely on the accumulation of proteins at DSBs, as part of the DDR. Such detection may be biased, as some factors and their modifications may not reflect physical DNA damage. The dependency on DDR markers of DSB detection tools has left questions unanswered. In particular, it is known that senescent cells display persistent DDR foci, that we and others have proposed to be persistent DSBs, resistant to endogenous DNA repair activities. Others have proposed that these peculiar DDR foci might not be sites of damaged DNA per se but instead stable chromatin modifications, termed DNA-SCARS. Here, we developed a method, named 'DNA damage in situ ligation followed by proximity ligation assay' (DI-PLA) for the detection and imaging of DSBs in cells. DI-PLA is based on the capture of free DNA ends in fixed cells in situ, by ligation to biotinylated double-stranded DNA oligonucleotides, which are next recognized by antibiotin anti-bodies. Detection is enhanced by PLA with a partner DDR marker at the DSB. We validated DI-PLA by demonstrating its ability to detect DSBs induced by various genotoxic insults in cultured cells and tissues. Most importantly, by DI-PLA, we demonstrated that both senescent cells in culture and tissues from aged mammals retain true unrepaired DSBs associated with DDR markers. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Linking JNK Activity to the DNA Damage Response

PubMed Central

Picco, Vincent

2013-01-01

The activity of c-Jun N-terminal kinase (JNK) was initially described as ultraviolet- and oncogene-induced kinase activity on c-Jun. Shortly after this initial discovery, JNK activation was reported for a wider variety of DNA-damaging agents, including γ-irradiation and chemotherapeutic compounds. As the DNA damage response mechanisms were progressively uncovered, the mechanisms governing the activation of JNK upon genotoxic stresses became better understood. In particular, a recent set of papers links the physical breakage in DNA, the activation of the transcription factor NF-κB, the secretion of TNF-α, and an autocrine activation of the JNK pathway. In this review, we will focus on the pathway that is initiated by a physical break in the DNA helix, leading to JNK activation and the resultant cellular consequences. The implications of these findings will be discussed in the context of cancer therapy with DNA-damaging agents. PMID:24349633

[Study on three kinds of gasoline oxygenates-induced DNA damage in mice fibroblasts].

PubMed

Song, Chonglin; Zhang, Zhifu; Chen, Xue; Zhang, Yanfeng; Wang, Chunhua; Liu, Keming

2002-10-01

To study DNA damage of three kinds of gasoline oxygenates. Single cell gel electrophoresis assay(Comet assay) was used to detect the damage effects of three gasoline oxygenates[methyl tertiary butyl ether(MTBE), ethanol anhydrous(EA) and dimethyl carbonate(DMC)] on DNA in L-929 mice fibroblasts. In certain concentation(37.500-150.000 mg/ml), MTBE could directly cause DNA damage of L-929 mice fibroblasts. There was obvious dose-effect relationship, i.e. when the concentration of MTBE was increased from 9.375 to 150.000 mg/ml, the comet rate also increased from 4% to 85%, and the length of comet tail changed correspondingly. The results of EA and DMC were negative. Under the condition of this experiment(150.000 mg/ml), MTBE could directly cause DNA damage while the effect of EA and DMC on DNA damage was not found.

How urban system vulnerabilities to flooding could be assessed to improve resilience and adaptation in spatial planning

NASA Astrophysics Data System (ADS)

Pasi, Riccardo; Viavattene, Christophe; La Loggia, Goffredo

2016-04-01

Natural hazards damage assets and infrastructure inducing disruptions to urban functions and key daily services. These disruptions may be short or long with a variable spatial scale of impact. From an urban planning perspective, measuring these disruptions and their consequences at an urban scale is fundamental in order to develop more resilient cities. Whereas the assessment of physical vulnerabilities and direct damages is commonly addressed, new methodologies for assessing the systemic vulnerability at the urban scale are required to reveal these disruptions and their consequences. Physical and systemic vulnerability should be measured in order to reflect the multifaceted fragility of cities in the face of external stress, both in terms of the natural/built environment and socio-economic sphere. Additionally, a systemic approach allows the consideration of vulnerability across different spatial scales, as impacts may vary and be transmitted across local, regional or national levels. Urban systems are spatially distributed and the nature of this can have significant effects on flood impacts. The proposed approach identifies the vulnerabilities of flooding within urban contexts, including both in terms of single elementary units (buildings, infrastructures, people, etc.) and systemic functioning (urban functions and daily life networks). Direct losses are appraised initially using conventional methodologies (e.g. depth-damage functions). This aims to both understand the spatial distribution of physical vulnerability and associated losses and, secondly, to identify the most vulnerable building types and ways to improve the physical adaptation of our cities, proposing changes to building codes, design principles and other municipal regulation tools. The subsequent systemic approach recognises the city as a collection of sub-systems or functional units (such as neighbourhoods and suburbs) providing key daily services for inhabitants (e.g. healthcare facilities, schools, administration offices, food shops, leisure and cultural services etc.) and which are interconnected through transport networks. Moreover, each city is part of broader systems - which may or may not follow administrative boundaries - and, as such, need to be connected to its wider surroundings, in a multi-scalar perspective. The systemic analysis, herein limited to residential households, evaluates the presence, the distribution among functional units and the redundancy of key daily services. As such, systemic interdependences between neighbourhoods/suburbs and municipalities emerge, highlighting how systemic vulnerability spreads beyond the flooded areas. This aims to understand which planning patterns and existing mixed-use developments are more flood resilient (thereby informing future urban development/regeneration) and which infrastructure and assets have a key role within the urban system (and have therefore to be prioritised for protection). The methodology is currently developed through an extensive use of Geographic Information Systems (GIS) and applied to an Italian case study (Noale municipality, Venice). Current developments and on-going issues in its application and in the data collection (including the use of aerial survey data) will be discussed in the presentation.

Chromosome aberrations in the blood lymphocytes of astronauts after space flight

NASA Technical Reports Server (NTRS)

George, K.; Durante, M.; Wu, H.; Willingham, V.; Badhwar, G.; Cucinotta, F. A.

2001-01-01

Cytogenetic analysis of the lymphocytes of astronauts provides a direct measurement of space radiation damage in vivo, which takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. Chromosome exchanges were measured in the blood lymphocytes of eight crew members after their respective space missions, using fluorescence in situ hybridization (FISH) with chromosome painting probes. Significant increases in aberrations were observed after the long-duration missions. The in vivo dose was derived from the frequencies of translocations and total exchanges using calibration curves determined before flight, and the RBE was estimated by comparison with individually measured physical absorbed doses. The values for average RBE were compared to the average quality factor (Q) from direct measurements of the lineal energy spectra using a tissue-equivalent proportional counter (TEPC) and radiation transport codes. The ratio of aberrations identified as complex was slightly higher after flight, which is thought to be an indication of exposure to high-LET radiation. To determine whether the frequency of complex aberrations measured in metaphase spreads after exposure to high-LET radiation was influenced by a cell cycle delay, chromosome damage was analyzed in prematurely condensed chromosome samples collected from two crew members before and after a short-duration mission. The frequency of complex exchanges after flight was higher in prematurely condensed chromosomes than in metaphase cells for one crew member.

Chromosome aberrations in the blood lymphocytes of astronauts after space flight.

PubMed

George, K; Durante, M; Wu, H; Willingham, V; Badhwar, G; Cucinotta, F A

2001-12-01

Cytogenetic analysis of the lymphocytes of astronauts provides a direct measurement of space radiation damage in vivo, which takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. Chromosome exchanges were measured in the blood lymphocytes of eight crew members after their respective space missions, using fluorescence in situ hybridization (FISH) with chromosome painting probes. Significant increases in aberrations were observed after the long-duration missions. The in vivo dose was derived from the frequencies of translocations and total exchanges using calibration curves determined before flight, and the RBE was estimated by comparison with individually measured physical absorbed doses. The values for average RBE were compared to the average quality factor (Q) from direct measurements of the lineal energy spectra using a tissue-equivalent proportional counter (TEPC) and radiation transport codes. The ratio of aberrations identified as complex was slightly higher after flight, which is thought to be an indication of exposure to high-LET radiation. To determine whether the frequency of complex aberrations measured in metaphase spreads after exposure to high-LET radiation was influenced by a cell cycle delay, chromosome damage was analyzed in prematurely condensed chromosome samples collected from two crew members before and after a short-duration mission. The frequency of complex exchanges after flight was higher in prematurely condensed chromosomes than in metaphase cells for one crew member.

Influence of Shear Stiffness Degradation on Crack Paths in Uni-Directional Composite Laminates

NASA Technical Reports Server (NTRS)

Satyanarayana, Arunkumar; Bogert, Phil B.

2017-01-01

Influence of shear stiffness degradation in an element, due to damage, on crack paths in uni-directional laminates has been demonstrated. A new shear stiffness degradation approach to improve crack path prediction has been developed and implemented in an ABAQUS/Explicit frame work using VUMAT. Three progressive failure analysis models, built-in ABAQUS (TradeMark), original COmplete STress Reduction (COSTR) and the modified COSTR damage models have been utilized in this study to simulate crack paths in five unidirectional notched laminates, 15deg, 30deg, 45deg, 60deg and 75deg under uniaxial tension load. Results such as crack paths and load vs. edge displacement curves are documented in this report. Modified COSTR damage model shows better accuracy in predicting crack paths in all the uni-directional laminates compared to the ABAQUS (TradeMark) and the original COSTR damage models.

INHIBITION OF FRIED MEAT-INDUCED DNA DAMAGE: A DIETARY INTERVENTION STUDY IN HUMANS

EPA Science Inventory

Dietary exposures have been implicated as risk factors in colorectal cancer. Such agents may act by causing DNA damage or may be protective against DNA damage. The effects of dietary exposures in causing or preventing damage have not been assessed directly in colon tissues. In th...

Physics must join with biology in better assessing risk from low-dose irradiation.

PubMed

Feinendegen, L E; Neumann, R D

2005-01-01

This review summarises the complex response of mammalian cells and tissues to low doses of ionising radiation. This thesis encompasses induction of DNA damage, and adaptive protection against both renewed damage and against propagation of damage from the basic level of biological organisation to the clinical expression of detriment. The induction of DNA damage at low radiation doses apparently is proportional to absorbed dose at the physical/chemical level. However, any propagation of such damage to higher levels of biological organisation inherently follows a sigmoid function. Moreover, low-dose-induced inhibition of damage propagation is not linear, but instead follows a dose-effect function typical for adaptive protection, after an initial rapid rise it disappears at doses higher than approximately 0.1-0.2 Gy to cells. The particular biological response duality at low radiation doses precludes the validity of the linear-no-threshold hypothesis in the attempt to relate absorbed dose to cancer. In fact, theory and observation support not only a lower cancer incidence than expected from the linear-no-threshold hypothesis, but also a reduction of spontaneously occurring cancer, a hormetic response, in the healthy individual.

Assessment of DNA damage in a group of professional dancers during a 10-month dancing season.

PubMed

Esteves, Filipa; Teixeira, Eduardo; Amorim, Tânia; Costa, Carla; Pereira, Cristiana; Fraga, Sónia; De Andrade, Vanessa Moraes; Teixeira, João Paulo; Costa, Solange

2017-01-01

Despite the numerous health benefits of physical activity, some studies reported that increased intensity and duration may induce oxidative stress in several cellular components including DNA. The aim of this study was to assess the level of basal DNA damage as well as oxidative DNA damage in a group of professional dancers before and after a 10-month dancing season. A group of individuals from general population was also assessed as a control. The alkaline version of the comet assay was the method selected to measure both basal DNA damage and oxidative stress, since this method quantifies both endpoints. In order to measure oxidative stress, the comet assay was coupled with a lesion-specific endonuclease (formamidopyrimidine glycosylase) to detect oxidized purines. The levels of oxidative DNA damage in dancers were significantly increased after the dancing season. Pre-season levels of oxidative DNA damage were lower in dancers than those obtained from the general population, suggesting an adaptation of antioxidant system in dancers. Results of the present biomonitoring study indicate the need for more effective measures to protect ballet dancers from potentially occupational health risks related to regular intensive physical exercise.

Single-Input and Multiple-Output Surface Acoustic Wave Sensing for Damage Quantification in Piezoelectric Sensors.

PubMed

Pamwani, Lavish; Habib, Anowarul; Melandsø, Frank; Ahluwalia, Balpreet Singh; Shelke, Amit

2018-06-22

The main aim of the paper is damage detection at the microscale in the anisotropic piezoelectric sensors using surface acoustic waves (SAWs). A novel technique based on the single input and multiple output of Rayleigh waves is proposed to detect the microscale cracks/flaws in the sensor. A convex-shaped interdigital transducer is fabricated for excitation of divergent SAWs in the sensor. An angularly shaped interdigital transducer (IDT) is fabricated at 0 degrees and ±20 degrees for sensing the convex shape evolution of SAWs. A precalibrated damage was introduced in the piezoelectric sensor material using a micro-indenter in the direction perpendicular to the pointing direction of the SAW. Damage detection algorithms based on empirical mode decomposition (EMD) and principal component analysis (PCA) are implemented to quantify the evolution of damage in piezoelectric sensor material. The evolution of the damage was quantified using a proposed condition indicator (CI) based on normalized Euclidean norm of the change in principal angles, corresponding to pristine and damaged states. The CI indicator provides a robust and accurate metric for detection and quantification of damage.

Long Duration Exposure Facility (LDEF) low-temperature heat pipe experiment package power system results

NASA Technical Reports Server (NTRS)

Tiller, Smith E.; Sullivan, David

1992-01-01

An overview of a self-contained Direct Energy Transfer Power System which was developed to provide power to the Long Duration Exposure Facility (LDEF) Low-Temperature Heat Pipe Experiment Package is presented. The power system operated successfully for the entire mission. Data recorded by the onboard recorder shows that the system operated within design specifications. Other than unanticipated overcharging of the battery, the power system operated as expected for nearly 32,000 low earth orbit cycles, and was still operational when tested after the LDEF recovery. Some physical damage was sustained by the solar array panels due to micrometeoroid hits, but there were not electrical failures.

Effects of taurine on markers of muscle damage, inflammatory response and physical performance in triathletes.

PubMed

Martinez Galan, Bryan S; Giolo de Carvalho, Flavia; Carvalho Santos, Priscila; Bucken Gobbi, Ronaldo; Kalva-Filho, Carlos; Papoti, Marcelo; Sanchez Silva, Adelino; Freitas, Ellen C

2017-07-25

The practice of prolonged exercise with high intensity, as seen in triathlon training, can cause physiological imbalances that might result in muscle fatigue, muscle damage and changes in systemic inflammatory response, thus reduce the athletes physical performance, therefore, both adequate total caloric and macronutrient intake also the use of a specific ergogenic aid, as taurine supplementation would be an alternative to prevent inflammation and muscle damage. In order to verify the effects of 8 weeks of taurine and chocolate milk supplementation, markers of muscle damage, inflammation, and aerobic capacity were quantified in triathletes. A double-blind, crossover, randomized study was conducted with 9 male long distance triathletes, aged 25-35 years. Supplementation of 3 g of taurine (TAU) or placebo (PLA) associated with 400 ml low fat chocolate milk was performed during an 8-week period. In order to verify the effects of the supplementation protocol markers of muscle damage as lactate dehydrogenase (LDH) and creatine kinase (CK), and inflammatory markers tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were quantified, also triathletes performance was evaluated by exhaust test on a treadmill. It was observed a significant increase in taurine and CK plasma levels after TAU supplementation (p=0.02 and p=0.01, respectively). However, LDH concentrations did not differ significantly after the supplementations performed, and there were no changes in physical performance parameters; anaerobic threshold, perceived exertion, heart rate, and the concentrations of IL-6 and TNF-α. Taurine supplementation did not provide benefits on performance and muscle damage in triathletes.

A Binary-Encounter-Bethe Approach to Simulate DNA Damage by the Direct Effect

NASA Technical Reports Server (NTRS)

Plante, Ianik; Cucinotta, Francis A.

2013-01-01

The DNA damage is of crucial importance in the understanding of the effects of ionizing radiation. The main mechanisms of DNA damage are by the direct effect of radiation (e.g. direct ionization) and by indirect effect (e.g. damage by.OH radicals created by the radiolysis of water). Despite years of research in this area, many questions on the formation of DNA damage remains. To refine existing DNA damage models, an approach based on the Binary-Encounter-Bethe (BEB) model was developed[1]. This model calculates differential cross sections for ionization of the molecular orbitals of the DNA bases, sugars and phosphates using the electron binding energy, the mean kinetic energy and the occupancy number of the orbital. This cross section has an analytic form which is quite convenient to use and allows the sampling of the energy loss occurring during an ionization event. To simulate the radiation track structure, the code RITRACKS developed at the NASA Johnson Space Center is used[2]. This code calculates all the energy deposition events and the formation of the radiolytic species by the ion and the secondary electrons as well. We have also developed a technique to use the integrated BEB cross section for the bases, sugar and phosphates in the radiation transport code RITRACKS. These techniques should allow the simulation of DNA damage by ionizing radiation, and understanding of the formation of double-strand breaks caused by clustered damage in different conditions.

3D Microstructures for Materials and Damage Models

DOE PAGES

Livescu, Veronica; Bronkhorst, Curt Allan; Vander Wiel, Scott Alan

2017-02-01

Many challenges exist with regard to understanding and representing complex physical processes involved with ductile damage and failure in polycrystalline metallic materials. Currently, the ability to accurately predict the macroscale ductile damage and failure response of metallic materials is lacking. Research at Los Alamos National Laboratory (LANL) is aimed at building a coupled experimental and computational methodology that supports the development of predictive damage capabilities by: capturing real distributions of microstructural features from real material and implementing them as digitally generated microstructures in damage model development; and, distilling structure-property information to link microstructural details to damage evolution under a multitudemore » of loading states.« less

Evaluation of DNA damage induced by Auger electrons from 137Cs.

PubMed

Watanabe, Ritsuko; Hattori, Yuya; Kai, Takeshi

2016-11-01

To understand the biological effect of external and internal exposure from 137 Cs, DNA damage spectrum induced by directly emitted electrons (γ-rays, internal conversion electrons, Auger electrons) from 137 Cs was compared with that induced by 137 Cs γ-rays. Monte Carlo track simulation method was used to calculate the microscopic energy deposition pattern in liquid water. Simulation was performed for the two simple target systems in microscale. Radiation sources were placed inside for one system and outside for another system. To simulate the energy deposition by directly emitted electrons from 137 Cs placed inside the system, the multiple ejections of electrons after internal conversion were considered. In the target systems, induction process of DNA damage was modeled and simulated for both direct energy deposition and the water radical reaction on the DNA. The yield and spatial distribution of simple and complex DNA damage including strand breaks and base lesions were calculated for irradiation by electrons and γ-rays from 137 Cs. The simulation showed that the significant difference in DNA damage spectrum was not caused by directly ejected electrons and γ-rays from 137 Cs. The result supports the existing perception that the biological effects by internal and external exposure by 137 Cs are equivalent.

Abortion Services and Military Medical Facilities

DTIC Science & Technology

2010-12-16

used to perform an abortion except where the life of the mother would be endangered if the fetus were carried to term or in a case in which the...and long -lasting physical health damage to the mother would result if the pregnancy were carried to term when so determined by two physicians. Nor...restrictions with regard to the “severe and long -lasting physical health damage to the mother that would result if the pregnancy were carried to term when so

Economic valuation of landslide damage in hilly regions: a case study from Flanders, Belgium.

PubMed

Vranken, Liesbet; Van Turnhout, Pieter; Van Den Eeckhaut, Miet; Vandekerckhove, Liesbeth; Poesen, Jean

2013-03-01

Several regions around the globe are at risk of incurring damage from landslides, but only few studies have concentrated on a quantitative estimate of the overall damage caused by landslides at a regional scale. This study therefore starts with a quantitative economic assessment of the direct and indirect damage caused by landslides in a 2,910 km study area located west of Brussels, a low-relief region susceptible to landslides. Based on focus interviews as well as on semi-structured interviews with homeowners, civil servants and the owners and providers of lifelines such as electricity and sewage, a quantitative damage assessment is provided. For private properties (houses, forest and pasture land) we estimate the real estate and production value losses for different damage scenarios, while for public infrastructure the costs of measures to repair and prevent landslide induced damage are estimated. In addition, the increase in amenity value of forests and grasslands due to the occurrence of landslides is also calculated. The study illustrates that a minority of land (only 2.3%) within the study area is used for dwellings, roads and railway lines, but that these land use types are responsible for the vast majority of the economic damage due to the occurrence of landslides. The annual cost of direct damage due to landsliding amounts to 688,148 €/year out of which 550,740 €/year for direct damage to houses, while the annual indirect damage augments to 3,020,049 €/year out of which 2,007,375 €/year for indirect damage to real estate. Next, the study illustrates that the increase of the amenity value of forests and grasslands outweighs the production value loss. As such the study does not only provide quantitative input data for the estimation of future risks, but also important information for government officials as it clearly informs about the costs associated with certain land use types in landslide areas. Copyright © 2013 Elsevier B.V. All rights reserved.

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

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

Rezaee, Mohammad, E-mail: Mohammad.Rezaee@USherbrooke.ca; Hunting, Darel J.; Sanche, Léon

2014-07-15

Purpose: The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods: Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by{sup 125}I withinmore » DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results: For a single decay of{sup 125}I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm{sup 3} volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions: Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide.« less

Correlation between energy deposition and molecular damage from Auger electrons: A case study of ultra-low energy (5–18 eV) electron interactions with DNA

PubMed Central

Rezaee, Mohammad; Hunting, Darel J.; Sanche, Léon

2015-01-01

Purpose The present study introduces a new method to establish a direct correlation between biologically related physical parameters (i.e., stopping and damaging cross sections, respectively) for an Auger-electron emitting radionuclide decaying within a target molecule (e.g., DNA), so as to evaluate the efficacy of the radionuclide at the molecular level. These parameters can be applied to the dosimetry of Auger electrons and the quantification of their biological effects, which are the main criteria to assess the therapeutic efficacy of Auger-electron emitting radionuclides. Methods Absorbed dose and stopping cross section for the Auger electrons of 5–18 eV emitted by 125I within DNA were determined by developing a nanodosimetric model. The molecular damages induced by these Auger electrons were investigated by measuring damaging cross section, including that for the formation of DNA single- and double-strand breaks. Nanoscale films of pure plasmid DNA were prepared via the freeze-drying technique and subsequently irradiated with low-energy electrons at various fluences. The damaging cross sections were determined by employing a molecular survival model to the measured exposure–response curves for induction of DNA strand breaks. Results For a single decay of 125I within DNA, the Auger electrons of 5–18 eV deposit the energies of 12.1 and 9.1 eV within a 4.2-nm3 volume of a hydrated or dry DNA, which results in the absorbed doses of 270 and 210 kGy, respectively. DNA bases have a major contribution to the deposited energies. Ten-electronvolt and high linear energy transfer 100-eV electrons have a similar cross section for the formation of DNA double-strand break, while 100-eV electrons are twice as efficient as 10 eV in the induction of single-strand break. Conclusions Ultra-low-energy electrons (<18 eV) substantially contribute to the absorbed dose and to the molecular damage from Auger-electron emitting radionuclides; hence, they should be considered in the dosimetry calculation of such radionuclides. Moreover, absorbed dose is not an appropriate physical parameter for nanodosimetry. Instead, stopping cross section, which describes the probability of energy deposition in a target molecule can be an appropriate nanodosimetric parameter. The stopping cross section is correlated with a damaging cross section (e.g., cross section for the double-strand break formation) to quantify the number of each specific lesion in a target molecule for each nuclear decay of a single Auger-electron emitting radionuclide. PMID:24989405

A novel methodology for the objective ascertainment of psychic and existential damage.

PubMed

Ferrara, Santo Davide; Ananian, Viviana; Baccino, Eric; Boscolo-Berto, Rafael; Domenici, Ranieri; Hernàndez-Cueto, Claudio; Mendelson, George; Norelli, Gian Aristide; Ranavaya, Mohammed; Terranova, Claudio; Vieira, Duarte Nuno; Viel, Guido; Villanueva, Enrique; Zoia, Riccardo; Sartori, Giuseppe

2016-09-01

Personal injury is a legal term for a physical or psychic injury suffered by the plaintiff under civil and/or tort law. With reference to non-pecuniary damages, the evidence itself of physical and/or psychic injury is not sufficient for damage compensation. The process of ascertaining impairments and/or disabilities which pertain to the "personal sphere" of the individual, such as pain and suffering, loss of amenity, and/or psycho-existential damage, poses particular difficulties in relation to the obtainment of scientific evidence. The "immateriality" and the subjective connotation of the personal sphere are, in themselves, critical issues. The clinical data obtained from the neuropsychological ascertainment find their essential prerequisite in the active participation of the examinee who, in legally relevant contexts (criminal law, civil law, insurance), may be "affected" by personal interests. The present manuscript presents a novel interdisciplinary methodology, experimented on a series of judicial and extra-judicial cases, aimed at the attainment of objectivity and accuracy eligible in relation to the judicial settlement of cases and other matters involving the ascertainment of peculiar aspects of non-pecuniary damage.

Flood damage curves for consistent global risk assessments

NASA Astrophysics Data System (ADS)

de Moel, Hans; Huizinga, Jan; Szewczyk, Wojtek

2016-04-01

Assessing potential damage of flood events is an important component in flood risk management. Determining direct flood damage is commonly done using depth-damage curves, which denote the flood damage that would occur at specific water depths per asset or land-use class. Many countries around the world have developed flood damage models using such curves which are based on analysis of past flood events and/or on expert judgement. However, such damage curves are not available for all regions, which hampers damage assessments in those regions. Moreover, due to different methodologies employed for various damage models in different countries, damage assessments cannot be directly compared with each other, obstructing also supra-national flood damage assessments. To address these problems, a globally consistent dataset of depth-damage curves has been developed. This dataset contains damage curves depicting percent of damage as a function of water depth as well as maximum damage values for a variety of assets and land use classes (i.e. residential, commercial, agriculture). Based on an extensive literature survey concave damage curves have been developed for each continent, while differentiation in flood damage between countries is established by determining maximum damage values at the country scale. These maximum damage values are based on construction cost surveys from multinational construction companies, which provide a coherent set of detailed building cost data across dozens of countries. A consistent set of maximum flood damage values for all countries was computed using statistical regressions with socio-economic World Development Indicators from the World Bank. Further, based on insights from the literature survey, guidance is also given on how the damage curves and maximum damage values can be adjusted for specific local circumstances, such as urban vs. rural locations, use of specific building material, etc. This dataset can be used for consistent supra-national scale flood damage assessments, and guide assessment in countries where no damage model is currently available.

75 FR 27419 - Airworthiness Directives; BAE Systems (Operations) Limited Model BAe 146 and Avro 146-RJ70A, 146...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-17

... environmental and fatigue inspections would not have detected the corrosion or fatigue damage. Corrosion or fatigue damage in this area, if not detected and corrected, could lead to degradation of the structural... fatigue inspections would not have detected the corrosion or fatigue damage. Corrosion or fatigue damage...

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

Livescu, Veronica; Bronkhorst, Curt Allan; Vander Wiel, Scott Alan

Many challenges exist with regard to understanding and representing complex physical processes involved with ductile damage and failure in polycrystalline metallic materials. Currently, the ability to accurately predict the macroscale ductile damage and failure response of metallic materials is lacking. Research at Los Alamos National Laboratory (LANL) is aimed at building a coupled experimental and computational methodology that supports the development of predictive damage capabilities by: capturing real distributions of microstructural features from real material and implementing them as digitally generated microstructures in damage model development; and, distilling structure-property information to link microstructural details to damage evolution under a multitudemore » of loading states.« less

Improving atomic displacement and replacement calculations with physically realistic damage models

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

Nordlund, Kai; Zinkle, Steven J.; Sand, Andrea E.

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor ofmore » 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.« less

Improving atomic displacement and replacement calculations with physically realistic damage models

DOE PAGES

Nordlund, Kai; Zinkle, Steven J.; Sand, Andrea E.; ...

2018-03-14

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor ofmore » 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.« less

Improving atomic displacement and replacement calculations with physically realistic damage models.

PubMed

Nordlund, Kai; Zinkle, Steven J; Sand, Andrea E; Granberg, Fredric; Averback, Robert S; Stoller, Roger; Suzudo, Tomoaki; Malerba, Lorenzo; Banhart, Florian; Weber, William J; Willaime, Francois; Dudarev, Sergei L; Simeone, David

2018-03-14

Atomic collision processes are fundamental to numerous advanced materials technologies such as electron microscopy, semiconductor processing and nuclear power generation. Extensive experimental and computer simulation studies over the past several decades provide the physical basis for understanding the atomic-scale processes occurring during primary displacement events. The current international standard for quantifying this energetic particle damage, the Norgett-Robinson-Torrens displacements per atom (NRT-dpa) model, has nowadays several well-known limitations. In particular, the number of radiation defects produced in energetic cascades in metals is only ~1/3 the NRT-dpa prediction, while the number of atoms involved in atomic mixing is about a factor of 30 larger than the dpa value. Here we propose two new complementary displacement production estimators (athermal recombination corrected dpa, arc-dpa) and atomic mixing (replacements per atom, rpa) functions that extend the NRT-dpa by providing more physically realistic descriptions of primary defect creation in materials and may become additional standard measures for radiation damage quantification.

The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases.

PubMed

Jia, Yu-Ping; Sun, Lei; Yu, He-Shui; Liang, Li-Peng; Li, Wei; Ding, Hui; Song, Xin-Bo; Zhang, Li-Juan

2017-04-20

Lutein (L) and zeaxanthin (Z) are dietary carotenoids derived from dark green leafy vegetables, orange and yellow fruits that form the macular pigment of the human eyes. It was hypothesized that they protect against visual disorders and cognition diseases, such as age-related macular degeneration (AMD), age-related cataract (ARC), cognition diseases, ischemic/hypoxia induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis and diabetic retinopathy. The mechanism by which they are involved in the prevention of eye diseases may be due their physical blue light filtration properties and local antioxidant activity. In addition to their protective roles against light-induced oxidative damage, there are increasing evidences that L and Z may also improve normal ocular function by enhancing contrast sensitivity and by reducing glare disability. Surveys about L and Z supplementation have indicated that moderate intakes of L and Z are associated with decreased AMD risk and less visual impairment. Furthermore, this review discusses the appropriate consumption quantities, the consumption safety of L, side effects and future research directions.

Laser-Based Surface Modification of Microstructure for Carbon Fiber-Reinforced Plastics

NASA Astrophysics Data System (ADS)

Yang, Wenfeng; Sun, Ting; Cao, Yu; Li, Shaolong; Liu, Chang; Tang, Qingru

2018-05-01

Bonding repair is a powerful feature of carbon fiber-reinforced plastics (CFRP). Based on the theory of interface bonding, the interface adhesion strength and reliability of the CFRP structure will be directly affected by the microscopic features of the CFRP surface, including the microstructure, physical, and chemical characteristics. In this paper, laser-based surface modification was compared to Peel-ply, grinding, and polishing to comparatively evaluate the surface microstructure of CFRP. The surface microstructure, morphology, fiber damage, height and space parameters were investigated by scanning electron microscopy (SEM) and laser confocal microscopy (LCM). Relative to the conventional grinding process, laser modification of the CFRP surface can result in more uniform resin removal and better processing control and repeatability. This decreases the adverse impact of surface fiber fractures and secondary damage. The surface properties were significantly optimized, which has been reflected such things as the obvious improvement of surface roughness, microstructure uniformity, and actual area. The improved surface microstructure based on laser modification is more conducive to interface bonding of CFRP structure repair. This can enhance the interfacial adhesion strength and reliability of repair.

Refinement of determination of critical thresholds of stress-strain behaviour by using AE data: potential for evaluation of durability of natural stone

NASA Astrophysics Data System (ADS)

Prikryl, Richard; Lokajíček, Tomáš

2017-04-01

According to previous studies, evaluation of stress-strain behaviour (in uniaxial compression) of various rocks appears to be effective tool allowing for prediction of resistance of natural stone to some physical weathering processes. Precise determination of critical thresholds, specifically of 'crack initiation' and 'crack damage' is fundamental issue in this approach. In contrast to 'crack damage stress/strain threshold', which can be easily read from deflection point on volumetric curve, detection of 'crack initiation' is much more difficult. Besides previously proposed mathematical processing of axial stress-strain curve, recording of acoustic emission (AE) data and their processing provide direct measure of various stress/strain thresholds, specifically of 'crack initiation'. This specific parameter is required during successive computation of energetic parameters (mechanical work), that can be stored by a material without formation of new defects (microcracks) due to acting stress. Based on our experimental data, this mechanical work seems to be proportional to the resistance of a material to formation of mode I (tensile) cracks that are responsible for destruction of subsurface below exposed faces of natural stone.

ATM directs DNA damage responses and proteostasis via genetically separable pathways.

PubMed

Lee, Ji-Hoon; Mand, Michael R; Kao, Chung-Hsuan; Zhou, Yi; Ryu, Seung W; Richards, Alicia L; Coon, Joshua J; Paull, Tanya T

2018-01-09

The protein kinase ATM is a master regulator of the DNA damage response but also responds directly to oxidative stress. Loss of ATM causes ataxia telangiectasia, a neurodegenerative disorder with pleiotropic symptoms that include cerebellar dysfunction, cancer, diabetes, and premature aging. We genetically separated the activation of ATM by DNA damage from that by oxidative stress using separation-of-function mutations. We found that deficient activation of ATM by the Mre11-Rad50-Nbs1 complex and DNA double-strand breaks resulted in loss of cell viability, checkpoint activation, and DNA end resection in response to DNA damage. In contrast, loss of oxidative activation of ATM had minimal effects on DNA damage-related outcomes but blocked ATM-mediated initiation of checkpoint responses after oxidative stress and resulted in deficiencies in mitochondrial function and autophagy. In addition, expression of a variant ATM incapable of activation by oxidative stress resulted in widespread protein aggregation. These results indicate a direct relationship between the mechanism of ATM activation and its effects on cellular metabolism and DNA damage responses in human cells and implicate ATM in the control of protein homeostasis. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

A physically-based continuum damage mechanics model for numerical prediction of damage growth in laminated composite plates

NASA Astrophysics Data System (ADS)

Williams, Kevin Vaughan

Rapid growth in use of composite materials in structural applications drives the need for a more detailed understanding of damage tolerant and damage resistant design. Current analytical techniques provide sufficient understanding and predictive capabilities for application in preliminary design, but current numerical models applicable to composites are few and far between and their development into well tested, rigorous material models is currently one of the most challenging fields in composite materials. The present work focuses on the development, implementation, and verification of a plane-stress continuum damage mechanics based model for composite materials. A physical treatment of damage growth based on the extensive body of experimental literature on the subject is combined with the mathematical rigour of a continuum damage mechanics description to form the foundation of the model. The model has been implemented in the LS-DYNA3D commercial finite element hydrocode and the results of the application of the model are shown to be physically meaningful and accurate. Furthermore it is demonstrated that the material characterization parameters can be extracted from the results of standard test methodologies for which a large body of published data already exists for many materials. Two case studies are undertaken to verify the model by comparison with measured experimental data. The first series of analyses demonstrate the ability of the model to predict the extent and growth of damage in T800/3900-2 carbon fibre reinforced polymer (CFRP) plates subjected to normal impacts over a range of impact energy levels. The predicted force-time and force-displacement response of the panels compare well with experimental measurements. The damage growth and stiffness reduction properties of the T800/3900-2 CFRP are derived using published data from a variety of sources without the need for parametric studies. To further demonstrate the physical nature of the model, a IM6/937 CFRP with a more brittle matrix system than 3900-2 is also analysed. Results of analyses performed under the same impact conditions do not compare as well quantitatively with measurements but the results are still promising and qualitative differences between the T800/3900-2 and IM6/937 are accurately captured. Finally, to further demonstrate the capability of the model, the response of a notched CFRP plate under quasi-static tensile loading is simulated and compared to experimental measurements. Of particular significance is the fact that the experimental test modelled in this case is uniquely suited to the characterization of the strain softening phenomenon observed in FRP laminates. Results of this virtual experiment compare very favourably with the measured damage growth and force-displacement curves.

Can Youthful Students be Encouraged to Self-repair Damaged Vision Using Elementary Mathematics and Physics Principles?

NASA Astrophysics Data System (ADS)

Ferreira, Nadja; McLeod, Roger

2006-03-01

Safe and easy self-repair of damaged vision in youth, detected from squinted eyes, motivated by simple applied math and physics, and over-stretched elastics. Parental permission and participation, with math skills of numerical cancellation, bring physics understanding to students. They recognize pupil diameter changes with light intensity. Ideas of focal surfaces and wavelength dependence can be achieved by burning paper with a magnifying glass, and dispersing light with a prism. Safeness of eye and head movements required are like those of the mother in applying makeup, or of a father in shaving. Easily defined, performed and monitored visual tasks can complete the repair(s).

Free radicals and low-level photon emission in human pathogenesis: state of the art.

PubMed

Van Wijk, Roeland; Van Wijk, Eduard P A; Wiegant, Fred A C; Ives, John

2008-05-01

Convincing evidence supports a role for oxidative stress in the pathogenesis of many chronic diseases. The model includes the formation of radical oxygen species (ROS) and the misassembly and aggregation of proteins when three tiers of cellular defence are insufficient: (a) direct antioxidative systems, (b) molecular damage repairing systems, and (c) compensatory chaperone synthesis. The aim of the present overview is to introduce (a) the basics of free radical and antioxidant metabolism, (b) the role of the protein quality control system in protecting cells from free radical damage and its relation to chronic diseases, (c) the basics of the ultraweak luminescence as marker of the oxidant status of biological systems, and (d) the research in human photon emission as a non-invasive marker of oxidant status in relation to chronic diseases. In considering the role of free radicals in disease, both their generation and their control by the antioxidant system are part of the story. Excessive free radical production leads to the production of heat shock proteins and chaperone proteins as a second line of protection against damage. Chaperones at the molecular level facilitate stress regulation vis-à-vis protein quali y control mechanisms. The manifestation of misfolded proteins and aggregates is a hallmark of a range of neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amylotrophic lateral sclerosis, polyglutamine (polyQ) diseases, diabetes and many others. Each of these disorders exhibits aging-dependent onset and a progressive, usually fatal clinical course. The second part reviews the current status of human photon emission techniques and protocols for recording the human oxidative status. Sensitive photomultiplier tubes may provide a tool for non-invasive and continuous monitoring of oxidative metabolism. In that respect, recording ultraweak luminescence has been favored compared to other indirect assays. Several biological models have been used to illustrate the technique in cell cultures and organs in vivo. This initiated practical applications addressing specific human pathological issues. Systematic studies on human emission have presented information on: (a) procedures for reliable measurements, and spectral analysis, (b) anatomic intensity of emission and left-right symmetries, (c) biological rhythms in emission, (d) physical and psychological influences on emission, (e) novel physical characteristics of emission, and (f) the identification of ultraweak photon emission with the staging of ROS-related damage and disease. It is concluded that both patterns and physical properties of ultraweak photon emission hold considerable promise as measure for the oxidative status.

Protective effects of physical exercise on MDMA-induced cognitive and mitochondrial impairment.

PubMed

Taghizadeh, Ghorban; Pourahmad, Jalal; Mehdizadeh, Hajar; Foroumadi, Alireza; Torkaman-Boutorabi, Anahita; Hassani, Shokoufeh; Naserzadeh, Parvaneh; Shariatmadari, Reyhaneh; Gholami, Mahdi; Rouini, Mohammad Reza; Sharifzadeh, Mohammad

2016-10-01

Debate continues about the effect of 3, 4-methylenedioxymethamphetamine (MDMA) on cognitive and mitochondrial function through the CNS. It has been shown that physical exercise has an important protective effect on cellular damage and death. Therefore, we investigated the effect of physical exercise on MDMA-induced impairments of spatial learning and memory as well as MDMA effects on brain mitochondrial function in rats. Male wistar rats underwent short-term (2 weeks) or long-term (4 weeks) treadmill exercise. After completion of exercise duration, acquisition and retention of spatial memory were evaluated by Morris water maze (MWM) test. Rats were intraperitoneally (I.P) injected with MDMA (5, 10, and 15mg/kg) 30min before the first training trial in 4 training days of MWM. Different parameters of brain mitochondrial function were measured including the level of ROS production, mitochondrial membrane potential (MMP), mitochondrial swelling, mitochondrial outermembrane damage, the amount of cytochrome c release from the mitochondria, and ADP/ATP ratio. MDMA damaged the spatial learning and memory in a dose-dependent manner. Brain mitochondria isolated from the rats treated with MDMA showed significant increase in ROS formation, collapse of MMP, mitochondrial swelling, and outer membrane damage, cytochrome c release from the mitochondria, and finally increased ADP/ATP ratio. This study also found that physical exercise significantly decreased the MDMA-induced impairments of spatial learning and memory and also mitochondrial dysfunction. The results indicated that MDMA-induced neurotoxicity leads to brain mitochondrial dysfunction and subsequent oxidative stress is followed by cognitive impairments. However, physical exercise could reduce these deleterious effects of MDMA through protective effects on brain mitochondrial function. Copyright © 2016 Elsevier Inc. All rights reserved.

Toward a consistent modeling framework to assess multi-sectoral climate impacts.

PubMed

Monier, Erwan; Paltsev, Sergey; Sokolov, Andrei; Chen, Y-H Henry; Gao, Xiang; Ejaz, Qudsia; Couzo, Evan; Schlosser, C Adam; Dutkiewicz, Stephanie; Fant, Charles; Scott, Jeffery; Kicklighter, David; Morris, Jennifer; Jacoby, Henry; Prinn, Ronald; Haigh, Martin

2018-02-13

Efforts to estimate the physical and economic impacts of future climate change face substantial challenges. To enrich the currently popular approaches to impact analysis-which involve evaluation of a damage function or multi-model comparisons based on a limited number of standardized scenarios-we propose integrating a geospatially resolved physical representation of impacts into a coupled human-Earth system modeling framework. Large internationally coordinated exercises cannot easily respond to new policy targets and the implementation of standard scenarios across models, institutions and research communities can yield inconsistent estimates. Here, we argue for a shift toward the use of a self-consistent integrated modeling framework to assess climate impacts, and discuss ways the integrated assessment modeling community can move in this direction. We then demonstrate the capabilities of such a modeling framework by conducting a multi-sectoral assessment of climate impacts under a range of consistent and integrated economic and climate scenarios that are responsive to new policies and business expectations.

A comparative study on the effects of barite, ilmenite and bentonite on four suspension feeding bivalves.

PubMed

Strachan, Maia F; Kingston, Paul F

2012-10-01

The impact of drilling mud components on the filtration activity and survival of bivalve molluscs was investigated by exposing them to suspensions of 'standard' barite, finely milled barite, ilmenite and bentonite in sea water. Introduction of the components stimulated filtration activity in all four bivalves. In addition, the introduction of standard barite and ilmenite both had lethal effects, with none of the bivalves surviving the full duration of the experiments. In-vivo observations of the gill surfaces provided direct evidence of physical damage caused by the administration of barite and ilmenite. A marked difference between filtration activity and survival of animals dosed with 'standard' barite and 'fine' barite suggests that the observed effects were primarily caused by physical interference with gill function. The results also suggest that the use of fine barite in offshore drilling may provide a more favourable environmental impact profile than the use of ilmenite. Copyright © 2012. Published by Elsevier Ltd.

[Stalking: old behaviour new crime. Reflections on 11 cases assessed in the judicial district of Bari].

PubMed

Grattagliano, Ignazio; Cassibba, Rosalinda; Greco, Romy; Laudisa, Alessia; Torres, Annamaria; Mastromarino, Anita

2012-01-01

Specific definitions aside, the behaviours that are generally associated with stalking may be classified into three categories of acts: 1) following (including showing up at the victim's home and workplace, maintaining surveillance, and setting up coincidences); 2) communicating (by telephone, mail, leaving notes, graffiti, gifts, e-mail, and internet); including the ordering of goods and services in the victim's name; 3) attacking or committing acts of violence (threats, direct harassment of the victim or of people close to the victim, damaging of personal goods, false accusations, physical or sexual violence). The work here presented proposes to find empirical confirmation of the data cited in the scientific literature with particular attention paid to the studies carried out by Mullen, Pathé, Purcell and Meloy who proposed a criminological diagnostic category for stalkers, delineating their behaviors . We go on to highlight patterns of behavior, as well as physical and social characteristics as postulated by these authors, and found in the molesters investigated in this study.

A repellent to reduce mouse damage to longleaf pine seed

Treesearch

Dale L. Nolte; James P. Barnett

2000-01-01

Direct seeding is a potential method for reforestation of pines on many southern sites. The success of direct seeding, however, depends, at least in part, in reducing seed predation by birds and rodents. We conducted a series of tests to assess the efficacy of capsicum and thiram in reducing mouse damage to longleaf pine (Pinus palustris) seeds....

Children's Moral Judgments as a Function of Intention, Damage, and an Actor's Physical Harm.

ERIC Educational Resources Information Center

Suls, Jerry; Kalle, Robert J.

1979-01-01

Examines children's moral judgments of story characters who accidently harm themselves. Children in kindergarten and in grades 3 and 5 rated actors in stories which varied in terms of intention, damage, and harm to the actor. (SS)

Characterization of Whole Grain Pasta: Integrating Physical, Chemical, Molecular, and Instrumental Sensory Approaches.

PubMed

Marti, Alessandra; Cattaneo, Stefano; Benedetti, Simona; Buratti, Susanna; Abbasi Parizad, Parisa; Masotti, Fabio; Iametti, Stefania; Pagani, Maria Ambrogina

2017-11-01

The consumption of whole-grain food-including pasta-has been increasing steadily. In the case of whole-grain pasta, given the many different producers, it seems important to have some objective parameters to define its overall quality. In this study, commercial whole-grain pasta samples representative of the Italian market have been characterized from both molecular and electronic-senses (electronic nose and electronic tongue) standpoint in order to provide a survey of the properties of different commercial samples. Only 1 pasta product showed very low levels of heat damage markers (furosine and pyrraline), suggesting that this sample underwent to low temperature dry treatment. In all samples, the furosine content was directly correlated to protein structural indices, since protein structure compactness increased with increasing levels of heat damage markers. Electronic senses were able to discriminate among pasta samples according to the intensity of heat treatment during the drying step. Pasta sample with low furosine content was discriminated by umami taste and by sensors responding to aliphatic and inorganic compounds. Data obtained with this multidisciplinary approach are meant to provide hints for identifying useful indices for pasta quality. As observed for semolina pasta, objective parameters based on heat-damage were best suited to define the overall quality of wholegrain pasta, almost independently of compositional differences among commercial samples. Drying treatments of different intensity also had an impact on instrumental sensory traits that may provide a reliable alternative to analytical determination of chemical markers of heat damage in all cases where there is a need for avoiding time-consuming procedures. © 2017 Institute of Food Technologists®.

Influences of load characteristics on impaired control of grip forces in patients with cerebellar damage.

PubMed

Brandauer, B; Timmann, D; Häusler, A; Hermsdörfer, J

2010-02-01

Various studies showed a clear impairment of cerebellar patients to modulate grip force in anticipation of the loads resulting from movements with a grasped object. This failure corroborated the theory of internal feedforward models in the cerebellum. Cerebellar damage also impairs the coordination of multiple-joint movements and this has been related to deficient prediction and compensation of movement-induced torques. To study the effects of disturbed torque control on feedforward grip-force control, two self-generated load conditions with different demands on torque control-one with movement-induced and the other with isometrically generated load changes-were directly compared in patients with cerebellar degeneration. Furthermore the cerebellum is thought to be more involved in grip-force adjustment to self-generated loads than to externally generated loads. Consequently, an additional condition with externally generated loads was introduced to further test this hypothesis. Analysis of 23 patients with degenerative cerebellar damage revealed clear impairments in predictive feedforward mechanisms in the control of both self-generated load types. Besides feedforward control, the cerebellar damage also affected more reactive responses when the externally generated load destabilized the grip, although this impairment may vary with the type of load as suggested by control experiments. The present findings provide further support that the cerebellum plays a major role in predictive control mechanisms. However, this impact of the cerebellum does not strongly depend on the nature of the load and the specific internal forward model. Contributions to reactive (grip force) control are not negligible, but seem to be dependent on the physical characteristics of an externally generated load.

Biomolecular damage induced by ionizing radiation: the direct and indirect effects of low-energy electrons on DNA.

PubMed

Alizadeh, Elahe; Orlando, Thomas M; Sanche, Léon

2015-04-01

Many experimental and theoretical advances have recently allowed the study of direct and indirect effects of low-energy electrons (LEEs) on DNA damage. In an effort to explain how LEEs damage the human genome, researchers have focused efforts on LEE interactions with bacterial plasmids, DNA bases, sugar analogs, phosphate groups, and longer DNA moieties. Here, we summarize the current understanding of the fundamental mechanisms involved in LEE-induced damage of DNA and complex biomolecule films. Results obtained by several laboratories on films prepared and analyzed by different methods and irradiated with different electron-beam current densities and fluencies are presented. Despite varied conditions (e.g., film thicknesses and morphologies, intrinsic water content, substrate interactions, and extrinsic atmospheric compositions), comparisons show a striking resemblance in the types of damage produced and their yield functions. The potential of controlling this damage using molecular and nanoparticle targets with high LEE yields in targeted radiation-based cancer therapies is also discussed.

A macrophage response to Mycobacterium leprae phenolic glycolipid initiates nerve damage in leprosy

PubMed Central

Madigan, Cressida A.; Cambier, C.J.; Kelly-Scumpia, Kindra M.; Scumpia, Philip O.; Cheng, Tan-Yun; Zailaa, Joseph; Bloom, Barry R.; Moody, D. Branch; Smale, Stephen T.; Sagasti, Alvaro; Modlin, Robert L.; Ramakrishnan, Lalita

2018-01-01

SUMMARY Mycobacterium leprae causes leprosy, and is unique among mycobacterial diseases in producing peripheral neuropathy. This debilitating morbidity is attributed to axon demyelination resulting from direct interactions of the M. leprae-specific phenolic glycolipid 1 (PGL-1) with myelinating glia, and their subsequent infection. Here, we use transparent zebrafish larvae to visualize the earliest events of M. leprae-induced nerve damage. We find that demyelination and axonal damage are not directly initiated by M. leprae but by infected macrophages that patrol axons; demyelination occurs in areas of intimate contact. PGL-1 confers this neurotoxic response on macrophages: macrophages infected with M. marinum expressing PGL-1 also damage axons. PGL-1 induces nitric oxide synthase in infected macrophages, and the resultant increase in reactive nitrogen species damages axons by injuring their mitochondria and inducing demyelination. Our findings implicate the response of innate macrophages to M. leprae PGL-1 in initiating nerve damage in leprosy. PMID:28841420

A numerical model for predicting crack path and modes of damage in unidirectional metal matrix composites

NASA Technical Reports Server (NTRS)

Bakuckas, J. G.; Tan, T. M.; Lau, A. C. W.; Awerbuch, J.

1993-01-01

A finite element-based numerical technique has been developed to simulate damage growth in unidirectional composites. This technique incorporates elastic-plastic analysis, micromechanics analysis, failure criteria, and a node splitting and node force relaxation algorithm to create crack surfaces. Any combination of fiber and matrix properties can be used. One of the salient features of this technique is that damage growth can be simulated without pre-specifying a crack path. In addition, multiple damage mechanisms in the forms of matrix cracking, fiber breakage, fiber-matrix debonding and plastic deformation are capable of occurring simultaneously. The prevailing failure mechanism and the damage (crack) growth direction are dictated by the instantaneous near-tip stress and strain fields. Once the failure mechanism and crack direction are determined, the crack is advanced via the node splitting and node force relaxation algorithm. Simulations of the damage growth process in center-slit boron/aluminum and silicon carbide/titanium unidirectional specimens were performed. The simulation results agreed quite well with the experimental observations.

A Macrophage Response to Mycobacterium leprae Phenolic Glycolipid Initiates Nerve Damage in Leprosy.

PubMed

Madigan, Cressida A; Cambier, C J; Kelly-Scumpia, Kindra M; Scumpia, Philip O; Cheng, Tan-Yun; Zailaa, Joseph; Bloom, Barry R; Moody, D Branch; Smale, Stephen T; Sagasti, Alvaro; Modlin, Robert L; Ramakrishnan, Lalita

2017-08-24

Mycobacterium leprae causes leprosy and is unique among mycobacterial diseases in producing peripheral neuropathy. This debilitating morbidity is attributed to axon demyelination resulting from direct interaction of the M. leprae-specific phenolic glycolipid 1 (PGL-1) with myelinating glia and their subsequent infection. Here, we use transparent zebrafish larvae to visualize the earliest events of M. leprae-induced nerve damage. We find that demyelination and axonal damage are not directly initiated by M. leprae but by infected macrophages that patrol axons; demyelination occurs in areas of intimate contact. PGL-1 confers this neurotoxic response on macrophages: macrophages infected with M. marinum-expressing PGL-1 also damage axons. PGL-1 induces nitric oxide synthase in infected macrophages, and the resultant increase in reactive nitrogen species damages axons by injuring their mitochondria and inducing demyelination. Our findings implicate the response of innate macrophages to M. leprae PGL-1 in initiating nerve damage in leprosy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

26 CFR 301.7426-2 - Recovery of damages in certain cases.

Code of Federal Regulations, 2010 CFR

2010-04-01

... in the case of negligence), or the sum of— (1) Actual, direct economic damages as defined in § 301... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Recovery of damages in certain cases. 301.7426... the United States § 301.7426-2 Recovery of damages in certain cases. (a) In general. In addition to...

Herbivores and pathogens on Alnus viridis subsp. fruticosa in interior Alaska: effects of leaf, tree, and neighbour characteristics on damage levels

Treesearch

Christa P.H. Mulder; Bitty A. Roy; Sabine Gusewell

2008-01-01

Parasite damage strongly affects dynamics of boreal forests. Damage levels may be affected by climate change, either directly or indirectly through changes in properties of host trees. We examined how herbivore and pathogen damage in Alnus viridis subsp. fruticosa (Rupr.) Nym. depend on leaf morphology and chemistry, tree size...

Influence of physical exercise on traumatic brain injury deficits: scaffolding effect.

PubMed

Archer, Trevor

2012-05-01

Traumatic brain injury (TBI) may be due to a bump, blow, or jolt to the head or a penetrating head injury that disrupts normal brain function; it presents an ever-growing, serious public health problem that causes a considerable number of fatalities and cases of permanent disability annually. Physical exercise restores the healthy homeostatic regulation of stress, affect and the regulation of hypothalamic-pituitary-adrenal axis. Physical activity attenuates or reverses the performance deficits observed in neurocognitive tasks. It induces anti-apoptotic effects and buttresses blood-brain barrier intactness. Exercise offers a unique non-pharmacologic, non-invasive intervention that incorporates different regimes, whether dynamic or static, endurance, or resistance. Exercise intervention protects against vascular risk factors that include hypertension, diabetes, cellular inflammation, and aortic rigidity. It induces direct changes in cerebrovasculature that produce beneficial changes in cerebral blood flow, angiogenesis and vascular disease improvement. The improvements induced by physical exercise regimes in brain plasticity and neurocognitive performance are evident both in healthy individuals and in those afflicted by TBI. The overlap and inter-relations between TBI effects on brain and cognition as related to physical exercise and cognition may provide lasting therapeutic benefits for recovery from TBI. It seems likely that some modification of the notion of scaffolding would postulate that physical exercise reinforces the adaptive processes of the brain that has undergone TBI thereby facilitating the development of existing networks, albeit possibly less efficient, that compensate for those lost through damage. © Springer Science+Business Media, LLC 2011

Yields of damage to C4' deoxyribose and to pyrimidines in pUC18 by the direct effect of ionizing radiation.

PubMed

Peoples, Anita R; Lee, Jane; Weinfeld, Michael; Milligan, Jamie R; Bernhard, William A

2012-07-01

Our mechanistic understanding of damage formation in DNA by the direct effect relies heavily on what is known of free radical intermediates studied by EPR spectroscopy. Bridging this information to stable product formation requires methods with comparable sensitivities, a criterion met by the (32)P-post-labeling assay developed by Weinfeld and Soderlind, [Weinfeld,M. and Soderlind,K.-J.M. (1991) (32)P-Postlabeling detection of radiation-induced DNA damage: identification and estimation of thymine glycols and phosphoglycolate termini. Biochemistry, 30, 1091-1097] which when applied to the indirect effect, detected phosphoglycolate (pg) and thymine glycol (Tg). Here we applied this assay to the direct effect, measuring product yields in pUC18 films with hydration levels (Γ) of 2.5, 16 or 23 waters per nucleotide and X-irradiated at either 4 K or room temperature (RT). The yields of pg [G(pg)] for Γ ≈ 2.5 were 2.8 ± 0.2 nmol/J (RT) and 0.2 ± 0.3 nmol/J (4 K), which is evidence that the C4' radical contributes little to the total deoxyribose damage via the direct effect. The yield of detectable base damage [G(B*)] at Γ ≈ 2.5 was found to be 30.2 ± 1.0 nmol/J (RT) and 12.9 ± 0.7 nmol/J (4 K). While the base damage called B*, could be due to either oxidation or reduction, we argue that two reduction products, 5,6-dihydrouracil and 5,6-dihydrothymine, are the most likely candidates.

Hispanic health disparities after a flood disaster: results of a population-based survey of individuals experiencing home site damage in El Paso (Texas, USA).

PubMed

Collins, Timothy W; Jimenez, Anthony M; Grineski, Sara E

2013-04-01

In 2006, El Paso County, a predominantly Hispanic urban area, was affected by a flood disaster; 1,500 homes were damaged. We assessed the health impacts of the disaster upon 475 individuals whose homes were flood-damaged using mail survey data and logistic regression. Substantial proportions of individuals had one or more physical (43 %) or mental (18 %) health problem in the four months following the floods; 28 % had one or more injury or acute effect related to post-flood cleanup. Adverse event experiences, older age, and lower socioeconomic status were significantly associated with negative post-flood health outcomes in all three logistic regression models. A lack of access to healthcare, non-US citizenship, and English proficiency were significant predictors of negative outcomes in both the physical and mental health models, while Hispanic ethnicity (physical), native-birth (mental), and more serious home damage (cleanup) were significant predictors in one model each. The disaster had disproportionate negative health impacts on those who were more exposed, poorer, older, and with constrained resource-access. While a lack of US citizenship and Hispanic ethnicity were associated with higher risks, being less acculturated (i.e., English-deficient, foreign-born) may have protected against health impacts.

Nonlinear ultrasonics for material state awareness

NASA Astrophysics Data System (ADS)

Jacobs, L. J.

2014-02-01

Predictive health monitoring of structural components will require the development of advanced sensing techniques capable of providing quantitative information on the damage state of structural materials. By focusing on nonlinear acoustic techniques, it is possible to measure absolute, strength based material parameters that can then be coupled with uncertainty models to enable accurate and quantitative life prediction. Starting at the material level, this review will present current research that involves a combination of sensing techniques and physics-based models to characterize damage in metallic materials. In metals, these nonlinear ultrasonic measurements can sense material state, before the formation of micro- and macro-cracks. Typically, cracks of a measurable size appear quite late in a component's total life, while the material's integrity in terms of toughness and strength gradually decreases due to the microplasticity (dislocations) and associated change in the material's microstructure. This review focuses on second harmonic generation techniques. Since these nonlinear acoustic techniques are acoustic wave based, component interrogation can be performed with bulk, surface and guided waves using the same underlying material physics; these nonlinear ultrasonic techniques provide results which are independent of the wave type used. Recent physics-based models consider the evolution of damage due to dislocations, slip bands, interstitials, and precipitates in the lattice structure, which can lead to localized damage.

[Nursing Experience With a Patient With Gastrostomy Leakage Resulting in Moisture-Associated Skin Damage].

PubMed

Hsu, Mei-Yu; Hsu, Hsiao-Hui; Lyu, Ji-Yan

2016-10-01

Leakage is a common complication of gastrostomy. Exposure of the skin surrounding the gastrostomy tube to moisture or chemical irritants may cause moisture-associated skin damage (MASD) and seriously affect the patient's quality of life. This case study describes a nursing experience with gastrostomy leakage that resulted in MASD. An assessment conducted from July 29, 2015 to August 20, 2015 revealed that heavy gastronomy leakage had caused extensive skin erosion, ulceration, hyperplasia, and superficial infection. Simultaneously, the patient was required to conduct complex stoma care, which resulted in physical and psychological exhaustion. Changes in traditional tube and wound care were discussed on multiple occasions with an interdisciplinary healthcare team. Based on the evidence-based literature, we provide gastrostomy and MASD management strategies. Through team collaboration, we prevented gastric contents from contacting the patient's skin directly, improved patient comfort, controlled effluent and skin infections, maintained fluid and electrolyte balances, and acce-lerated the healing of the damaged skin. We recommend that healthcare professionals caring for patients with gastrostomy leakage be provided with early skin protection programs to learn the standard methods for identifying and correcting leakage factors, containing effluent, and adequately stabilizing the gastrostomy tube in order to reduce the impact on the patient's quality of life. In addition, patient education on tube and skin care should be provided to prevent the reoccurrence of complications.

Cancer Risk Assessment for Space Radiation

NASA Technical Reports Server (NTRS)

Richmond, Robert C.; Cruz, Angela; Bors, Karen; Curreri, Peter A. (Technical Monitor)

2001-01-01

Predicting the occurrence of human cancer following exposure to any agent causing genetic damage is a difficult task. This is because the uncertainty of uniform exposure to the damaging agent, and the uncertainty of uniform processing of that damage within a complex set of biological variables, degrade the confidence of predicting the delayed expression of cancer as a relatively rare event within any given clinically normal individual. The radiation health research priorities for enabling long-duration human exploration of space were established in the 1996 NRC Report entitled 'Radiation Hazards to Crews of Interplanetary Missions: Biological Issues and Research Strategies'. This report emphasized that a 15-fold uncertainty in predicting radiation-induced cancer incidence must be reduced before NASA can commit humans to extended interplanetary missions. That report concluded that the great majority of this uncertainty is biologically based, while a minority is physically based due to uncertainties in radiation dosimetry and radiation transport codes. Since that report, the biologically based uncertainty has remained large, and the relatively small uncertainty associated with radiation dosimetry has increased due to the considerations raised by concepts of microdosimetry. In a practical sense, however, the additional uncertainties introduced by microdosimetry are encouraging since they are in a direction of lowered effective dose absorbed through infrequent interactions of any given cell with the high energy particle component of space radiation. Additional information is contained in the original extended abstract.

Prostate-specific membrane antigen-directed nanoparticle targeting for extreme nearfield ablation of prostate cancer cells.

PubMed

Lee, Seung S; Roche, Philip Jr; Giannopoulos, Paresa N; Mitmaker, Elliot J; Tamilia, Michael; Paliouras, Miltiadis; Trifiro, Mark A

2017-03-01

Almost all biological therapeutic interventions cannot overcome neoplastic heterogeneity. Physical ablation therapy is immune to tumor heterogeneity, but nearby tissue damage is the limiting factor in delivering lethal doses. Multi-walled carbon nanotubes offer a number of unique properties: chemical stability, photonic properties including efficient light absorption, thermal conductivity, and extensive surface area availability for covalent chemical ligation. When combined together with a targeting moiety such as an antibody or small molecule, one can deliver highly localized temperature increases and cause extensive cellular damage. We have functionalized multi-walled carbon nanotubes by conjugating an antibody against prostate-specific membrane antigen. In our in vitro studies using prostate-specific membrane antigen-positive LNCaP prostate cancer cells, we have effectively demonstrated cell ablation of >80% with a single 30-s exposure to a 2.7-W, 532-nm laser for the first time without bulk heating. We also confirmed the specificity and selectivity of prostate-specific membrane antigen targeting by assessing prostate-specific membrane antigen-null PC3 cell lines under the same conditions (<10% cell ablation). This suggests that we can achieve an extreme nearfield cell ablation effect, thus restricting potential tissue damage when transferred to in vivo clinical applications. Developing this new platform will introduce novel approaches toward current therapeutic modalities and will usher in a new age of effective cancer treatment squarely addressing tumoral heterogeneity.

Logging damage to residual trees following commercial harvesting to different overstory retention levels in a mature hardwood stand in Tennessee

Treesearch

Wayne K. Clatterbuck

2006-01-01

Partial cutting in mature hardwood stands often causes physical damage to residual stems through felling and skidding resulting in a decline in bole quality and subsequent loss of tree value. This study assessed the logging damage to residual trees following commercial harvesting in a fully stocked, mature oak-hickory stand cut to three overstory basal area retention...

Postoperative morbidity and histopathologic characteristics of tonsillar tissue following coblation tonsillectomy in children: a prospective randomized single-blind study.

PubMed

Roje, Zeljka; Racić, Goran; Dogas, Zoran; Pisac, Valdi Pesutić; Timms, Michael

2009-03-01

The aim of this prospective randomized single blind study was to determine the depth of thermal damage to tonsillar tissue due to coblation, and to compare it with thermal damage to tonsillar tissue following conventional tonsillectomy; to correlate the depth of thermal damage to tonsillar tissue with the parameters of postoperative morbidity, to compare intraoperative blood loss, postoperative pain severity, time to resuming normal physical activity, and incidence of postoperative bleeding between two groups of tonsillectomized children aged up to 16 years. 72 children aged 3-16 years scheduled for tonsillectomy randomly assigned into two groups submitted either to conventional tonsillectomy with bipolar diathermy coagulation or to coblation tonsillectomy, with a 14-day follow up. Statistically significant differences were observed in the depth of thermal damage to tonsillar tissue (p < 0.001), intraoperative blood loss (p < 0.004), in postoperative pain severity (p < 0.05) and in time to resuming normal physical activity between the two groups (p < 0.001). There was no case of reactionary or secondary bleeding in either group. In this paper for the first time we have correlated postoperative morbidity and thermal tissue damage: less thermal damage is associated with less postoperative morbidity.

Physical Interpretation of Laboratory Friction Laws in the Context of Damage Physics

NASA Astrophysics Data System (ADS)

Rundle, J. B.; Tiampo, K. F.; Martins, J. S.; Klein, W.

2002-12-01

Frictional on sliding surfaces is ultimately related to processes of surface damage, and can be understood in the context of the physics of dynamical threshold systems. Threshold systems are known to be some of the most important nonlinear, self-organizing systems in nature, including networks of earthquake faults, neural networks, superconductors and semiconductors, and the World Wide Web, as well as political, social, and ecological systems. All of these systems have dynamics that are strongly correlated in space and time, and all typically display a multiplicity of spatial and temporal scales. Here we discuss the physics of self-organization and damage in earthquake threshold systems at the "microscopic" laboratory scale, in which consideration of results from simulations leads to dynamical equations that can be used to derive results obtained from sliding friction experiments, specifically, the empirical "rate-and-state" friction equations of Ruina. Paradoxically, in all of these dissipative systems, long-range interactions induce the existence of locally ergodic dynamics, even though the dissipation of energy is involved. The existence of dissipative effects leads to the appearance of a "leaky threshold" dynamics, equivalent to a new scaling field that controls the size of nucleation events relative to the size of the background fluctuations. The corresponding appearance of a mean field spinodal leads to a general coarse-grained equation, which expresses the balance between rate of stress supplied, and rate of stress dissipated in the processes leading to surface damage. We can use ideas from thermodynamics and kinetics of phase transitions to develop the exact form of the rate-and-state equations, giving clear physical meaning to all terms and variables. Ultimately, the self-organizing dynamics arise from the appearance of an energy landscape in these systems, which in turn arises from the strong correlations and mean field nature of the physics.

Wiring Damage Analyses for STS OV-103

NASA Technical Reports Server (NTRS)

Thomas, Walter, III

2006-01-01

This study investigated the Shuttle Program s belief that Space Transportation System (STS) wiring damage occurrences are random, that is, a constant occurrence rate. Using Problem Reporting and Corrective Action (PRACA)-derived data for STS Space Shuttle OV-103, wiring damage was observed to increase over the vehicle s life. Causal factors could include wiring physical deterioration, maintenance and inspection induced damage, and inspection process changes resulting in more damage events being reported. Induced damage effects cannot be resolved with existent data. Growth analysis (using Crow-AMSAA, or CA) resolved maintenance/inspection effects (e.g., heightened awareness) on all wire damages and indicated an overall increase since Challenger Return-to-Flight (RTF). An increasing failure or occurrence rate per flight cycle was seen for each wire damage mode; these (individual) rates were not affected by inspection process effects, within statistical error.

Cyclic fatigue damage characteristics observed for simple loadings extended to multiaxial life prediction

NASA Technical Reports Server (NTRS)

Jones, David J.; Kurath, Peter

1988-01-01

Fully reversed uniaxial strain controlled fatigue tests were performed on smooth cylindrical specimens made of 304 stainless steel. Fatigue life data and cracking observations for uniaxial tests were compared with life data and cracking behavior observed in fully reversed torsional tests. It was determined that the product of maximum principle strain amplitude and maximum principle stress provided the best correlation of fatigue lives for these two loading conditions. Implementation of this parameter is in agreement with observed physical damage and it accounts for the variation of stress-strain response, which is unique to specific loading conditions. Biaxial fatigue tests were conducted on tubular specimens employing both in-phase and out-of-phase tension torsion cyclic strain paths. Cracking observations indicated that the physical damage which occurred in the biaxial tests was similar to the damage observed in uniaxial and torsional tests. The Smith, Watson, and Topper parameter was then extended to predict the fatigue lives resulting from the more complex loading conditions.

Mapping the Structure of Directed Networks: Beyond the Bow-Tie Diagram

NASA Astrophysics Data System (ADS)

Timár, G.; Goltsev, A. V.; Dorogovtsev, S. N.; Mendes, J. F. F.

2017-02-01

We reveal a hierarchical, multilayer organization of finite components—i.e., tendrils and tubes—around the giant connected components in directed networks and propose efficient algorithms allowing one to uncover the entire organization of key real-world directed networks, such as the World Wide Web, the neural network of Caenorhabditis elegans, and others. With increasing damage, the giant components decrease in size while the number and size of tendril layers increase, enhancing the susceptibility of the networks to damage.

Estimating Power Outage Cost based on a Survey for Industrial Customers

NASA Astrophysics Data System (ADS)

Yoshida, Yoshikuni; Matsuhashi, Ryuji

A survey was conducted on power outage cost for industrial customers. 5139 factories, which are designated energy management factories in Japan, answered their power consumption and the loss of production value due to the power outage in an hour in summer weekday. The median of unit cost of power outage of whole sectors is estimated as 672 yen/kWh. The sector of services for amusement and hobbies and the sector of manufacture of information and communication electronics equipment relatively have higher unit cost of power outage. Direct damage cost from power outage in whole sectors reaches 77 billion yen. Then utilizing input-output analysis, we estimated indirect damage cost that is caused by the repercussion of production halt. Indirect damage cost in whole sectors reaches 91 billion yen. The sector of wholesale and retail trade has the largest direct damage cost. The sector of manufacture of transportation equipment has the largest indirect damage cost.

Information-theoretical noninvasive damage detection in bridge structures

NASA Astrophysics Data System (ADS)

Sudu Ambegedara, Amila; Sun, Jie; Janoyan, Kerop; Bollt, Erik

2016-11-01

Damage detection of mechanical structures such as bridges is an important research problem in civil engineering. Using spatially distributed sensor time series data collected from a recent experiment on a local bridge in Upper State New York, we study noninvasive damage detection using information-theoretical methods. Several findings are in order. First, the time series data, which represent accelerations measured at the sensors, more closely follow Laplace distribution than normal distribution, allowing us to develop parameter estimators for various information-theoretic measures such as entropy and mutual information. Second, as damage is introduced by the removal of bolts of the first diaphragm connection, the interaction between spatially nearby sensors as measured by mutual information becomes weaker, suggesting that the bridge is "loosened." Finally, using a proposed optimal mutual information interaction procedure to prune away indirect interactions, we found that the primary direction of interaction or influence aligns with the traffic direction on the bridge even after damaging the bridge.

Direct Detection and Sequencing of Damaged DNA Bases

PubMed Central

2011-01-01

Products of various forms of DNA damage have been implicated in a variety of important biological processes, such as aging, neurodegenerative diseases, and cancer. Therefore, there exists great interest to develop methods for interrogating damaged DNA in the context of sequencing. Here, we demonstrate that single-molecule, real-time (SMRT®) DNA sequencing can directly detect damaged DNA bases in the DNA template - as a by-product of the sequencing method - through an analysis of the DNA polymerase kinetics that are altered by the presence of a modified base. We demonstrate the sequencing of several DNA templates containing products of DNA damage, including 8-oxoguanine, 8-oxoadenine, O6-methylguanine, 1-methyladenine, O4-methylthymine, 5-hydroxycytosine, 5-hydroxyuracil, 5-hydroxymethyluracil, or thymine dimers, and show that these base modifications can be readily detected with single-modification resolution and DNA strand specificity. We characterize the distinct kinetic signatures generated by these DNA base modifications. PMID:22185597

Direct detection and sequencing of damaged DNA bases.

PubMed

Clark, Tyson A; Spittle, Kristi E; Turner, Stephen W; Korlach, Jonas

2011-12-20

Products of various forms of DNA damage have been implicated in a variety of important biological processes, such as aging, neurodegenerative diseases, and cancer. Therefore, there exists great interest to develop methods for interrogating damaged DNA in the context of sequencing. Here, we demonstrate that single-molecule, real-time (SMRT®) DNA sequencing can directly detect damaged DNA bases in the DNA template - as a by-product of the sequencing method - through an analysis of the DNA polymerase kinetics that are altered by the presence of a modified base. We demonstrate the sequencing of several DNA templates containing products of DNA damage, including 8-oxoguanine, 8-oxoadenine, O6-methylguanine, 1-methyladenine, O4-methylthymine, 5-hydroxycytosine, 5-hydroxyuracil, 5-hydroxymethyluracil, or thymine dimers, and show that these base modifications can be readily detected with single-modification resolution and DNA strand specificity. We characterize the distinct kinetic signatures generated by these DNA base modifications.

Strain Rate and Stress Triaxiality Effects on Ductile Damage of Additive Manufactured TI-6AL-4V

NASA Astrophysics Data System (ADS)

Iannitti, Gianluca; Bonora, Nicola; Gentile, Domenico; Ruggiero, Andrew; Testa, Gabriel; Gubbioni, Simone

2017-06-01

In this work, the effects of strain rate and stress triaxiality on ductile damage of additive manufactured Ti-6Al-4V, also considering the build direction, were investigated. Raw material was manufactured by means of EOSSINT M2 80 machine, based on Direct Metal Laser Sintering technology, and machined to obtain round notched bar and Rod-on-Rod (RoR) specimens. Tensile tests on round notched bar specimens were performed in a wide range of strain rates. The failure strains at different stress triaxiality were used to calibrate the Bonora Damage Model. In order to design the RoR tests, numerical simulations were performed for assessing velocities at which incipient and fully developed damage occur. Tests at selected velocities were carried out and soft-recovered specimens were sectioning and polishing to observe the developed damage. Nucleated voids maps were compared with numerical simulations results.

[Benefits of Decumanum Phlebodium intake on the muscle damage in the response to intense physical exercise in sedentary subjects].

PubMed

Vargas Corzo, M C; Aguilar Cordero, M J; de Teresa Galván, C; Segura Millán, D; Miranda Leon, M T; Castillo Rueda, G; Guisado Barrilao, R

2014-06-01

Intense physical exercise provoke muscle damage, that in sedentary people can increase cardiovascular risk. Phlebodium decumanum (PD) has shown to have immunomodulator effects in models of moderate intense physical activities in well conditioned groups. To evaluate the PD effects during eccentric exercise, as a model of muscle inflammation protocol, on a sedentary population with cardiovascular risk. This is an experimental, double-blind, multigroup randomized study. Experimental Group 1 (n = 17)received PD, 9 doses of 400 mg (total amount 3.6 g) every 8 hours during 3 days, and Control Group 2 (n = 16)received a placebo. All the subjects performed two treadmill ergoespirometry tests: first, a modified Bruce protocol to discard ischemic responses during exercise and to evaluate VO2max before the experimental phase;and second, with an eccentric protocol (14% descending ramp test) during 10 minutes in stable state at 70-80%VO2max, as experimental inflammatory protocol.We compared intra and inter groups to evaluate differences in the pre and post-test differences results on blood muscle damage variables. The study shown statistically significant differences in all pre-post intra-groups results in muscle damage variables (CK, LDH and Myoglobin, but not in Cardiac Troponin), and in functional lower-limb test (SJand CMJ). The comparison of inter-group results shown less muscle damage and less functional lower-limb deterioration in Group 1 compared with Control group, with statistical significance in both cases. Differences in handgrip dynamometry were no statistically significant. The eccentric exercise protocol in that study has proven to be a good model to induce muscle and functional damage in sedentary people. Short PD treatment has shown to reduce muscle and functional acute damages compared with placebo control group in this specific population. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

77 FR 67254 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-09

..., damage, and loose wiring within an ACCB and repair if necessary; and requires rework and re... necessary] and rectification [rework] of the wiring installation within each ACCB. You may obtain further... visual inspection for chafing, damage, and insulation damage, and rework the wiring within the ACCB, in...

76 FR 68366 - Airworthiness Directives; The Boeing Company Model 777-200 and -300 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-04

...-induced currents and subsequent damage to composite structures, hydraulic tubes, and actuator control... and could subsequently damage composite structures, hydraulic tubes, and actuator control electronics... subsequent damage to composite structures, hydraulic tubes, and actuator control electronics. In the event of...

Two-Phase Bactericidal Mechanism of Silver Nanoparticles against Burkholderia pseudomallei

PubMed Central

Hongsing, Nuttaya; Thammawithan, Saengrawee; Daduang, Sakda; Klaynongsruang, Sompong; Tuanyok, Apichai; Patramanon, Rina

2016-01-01

Silver nanoparticles (AgNPs) have a strong antimicrobial activity against a variety of pathogenic bacteria. The killing mechanism of AgNPs involves direct physical membrane destruction and subsequent molecular damage from both AgNPs and released Ag+. Burkholderia pseudomallei is the causative agent of melioidosis, an endemic infectious disease primarily found in northern Australia and Southeast Asia. B. pseudomallei is intrinsically resistant to most common antibiotics. In this study, the antimicrobial activity and mechanism of AgNPs (10–20 nm) against B. pseudomallei were investigated. The MIC and MBC for nine B. pseudomallei strains ranged from 32–48 μg/mL and 96–128 μg/mL, respectively. Concentrations of AgNPs less than 256 μg/mL were not toxic to human red blood cells. AgNPs exhibited a two-phase mechanism: cell death induction and ROS induction. The first phase was a rapid killing step within 5 min, causing the direct damage of the cytoplasmic membrane of the bacterial cells, as observed by a time-kill assay and fluorescence microscopy. During the period of 5–30 min, the cell surface charge was rapidly neutralized from -8.73 and -7.74 to 2.85 and 2.94 mV in two isolates of B. pseudomallei, as revealed by zeta potential measurement. Energy-dispersive X-ray (EDX) spectroscopy showed the silver element deposited on the bacterial membrane, and TEM micrographs of the AgNP-treated B. pseudomallei cells showed severe membrane damage and cytosolic leakage at 1/5 MIC and cell bursting at MBC. During the killing effect the released Ag+ from AgNPs was only 3.9% from the starting AgNPs concentration as observed with ICP-OES experiment. In the second phase, the ROS induction occurred 1–4 hr after the AgNP treatment. Altogether, we provide direct kinetic evidence of the AgNPs killing mechanism, by which cell death is separable from the ROS induction and AgNPs mainly contributes in the killing action. AgNPs may be considered a potential candidate to develop a novel alternative agent for melioidosis treatment with fast action. PMID:27977746

Religious Engagement in a Risky Family Model Predicting Health in Older Black and White Seventh-day Adventists.

PubMed

Morton, Kelly R; Lee, Jerry W; Haviland, Mark G; Fraser, Gary E

2012-11-01

In a structural equation model, associations among latent variables - Child Poverty, Risky Family exposure, Religious Engagement, Negative Social Interactions, Negative Emotionality, and Perceived Physical Health - were evaluated in 6,753 Black and White adults aged 35-106 years (M = 60.5, SD = 13.0). All participants were members of the Seventh-day Adventist church surveyed in the Biopsychosocial Religion and Health Study (BRHS). Child Poverty was positively associated with both Risky Family exposure (conflict, neglect, abuse) and Religious Engagement (intrinsic religiosity, religious coping, religiousness). Risky Family was negatively associated with Religious Engagement and positively associated with both Negative Social Interactions (intrusive, failed to help, insensitive, rejecting) and Negative Emotionality (depression, negative affect, neuroticism). Religious Engagement was negatively associated with Negative Emotionality and Negative Social Interactions at a given level of risky family. Negative Social Interactions was positively associated with Negative Emotionality, which had a direct, negative effect on Perceived Physical Health. All constructs had indirect effects on Perceived Physical Health through Negative Emotionality. The effects of a risky family environment appear to be enduring, negatively affecting one's adult religious life, emotionality, social interactions, and perceived health. Religious engagement, however, may counteract the damaging effects of early life stress.

A study on the relationship between compulsive exercise, depression and anxiety

PubMed Central

Weinstein, Aviv; Maayan, Gavriel; Weinstein, Yitzhak

2015-01-01

Background and Aims Exercise and physical activity are beneficial both physically and psychologically but a few individuals use exercise excessively resulting in physical and even psychological damage. There is evidence for bi-directional relationship between exercise with depression and anxiety showing that exercise can reduce anxiety and depression, whereas a lack of exercise is associated with higher levels of anxiety and depression. Methods This study used questionnaires assessing compulsive exercise, anxiety and depression among 20 professional regular exercisers and 51 recreational regular exercisers. Results Results showed that ratings of compulsive exercise were associated with ratings of anxiety and depression among individuals who exercise for professional and recreational purpose. Secondly, individuals who exercise for professional purpose were more depressed than individuals who exercise for recreational purpose, but did not exhibit higher trait anxiety ratings. Thirdly, individuals who exercise for recreational purpose showed an association between ratings of compulsive exercise and depression but not with ratings of trait anxiety. Discussion Individuals who exercise for professional and recreational purpose may use it as a means for alleviating depression and anxiety although this small sample of recreational and professional sportsmen showed clinical levels of anxiety and depression that may require further clinical treatment. PMID:26690627

A study on the relationship between compulsive exercise, depression and anxiety.

PubMed

Weinstein, Aviv; Maayan, Gavriel; Weinstein, Yitzhak

2015-12-01

Exercise and physical activity are beneficial both physically and psychologically but a few individuals use exercise excessively resulting in physical and even psychological damage. There is evidence for bi-directional relationship between exercise with depression and anxiety showing that exercise can reduce anxiety and depression, whereas a lack of exercise is associated with higher levels of anxiety and depression. This study used questionnaires assessing compulsive exercise, anxiety and depression among 20 professional regular exercisers and 51 recreational regular exercisers. Results showed that ratings of compulsive exercise were associated with ratings of anxiety and depression among individuals who exercise for professional and recreational purpose. Secondly, individuals who exercise for professional purpose were more depressed than individuals who exercise for recreational purpose, but did not exhibit higher trait anxiety ratings. Thirdly, individuals who exercise for recreational purpose showed an association between ratings of compulsive exercise and depression but not with ratings of trait anxiety. Individuals who exercise for professional and recreational purpose may use it as a means for alleviating depression and anxiety although this small sample of recreational and professional sportsmen showed clinical levels of anxiety and depression that may require further clinical treatment.

Cancer Risk Estimates from Space Flight Estimated Using Yields of Chromosome Damage in Astronaut's Blood Lymphocytes

NASA Technical Reports Server (NTRS)

George, Kerry A.; Rhone, J.; Chappell, L. J.; Cucinotta, F. A.

2011-01-01

To date, cytogenetic damage has been assessed in blood lymphocytes from more than 30 astronauts before and after they participated in long-duration space missions of three months or more on board the International Space Station. Chromosome damage was assessed using fluorescence in situ hybridization whole chromosome analysis techniques. For all individuals, the frequency of chromosome damage measured within a month of return from space was higher than their preflight yield, and biodosimetry estimates were within the range expected from physical dosimetry. Follow up analyses have been performed on most of the astronauts at intervals ranging from around 6 months to many years after flight, and the cytogenetic effects of repeat long-duration missions have so far been assessed in four individuals. Chromosomal aberrations in peripheral blood lymphocytes have been validated as biomarkers of cancer risk and cytogenetic damage can therefore be used to characterize excess health risk incurred by individual crewmembers after their respective missions. Traditional risk assessment models are based on epidemiological data obtained on Earth in cohorts exposed predominantly to acute doses of gamma-rays, and the extrapolation to the space environment is highly problematic, involving very large uncertainties. Cytogenetic damage could play a key role in reducing uncertainty in risk estimation because it is incurred directly in the space environment, using specimens from the astronauts themselves. Relative cancer risks were estimated from the biodosimetry data using the quantitative approach derived from the European Study Group on Cytogenetic Biomarkers and Health database. Astronauts were categorized into low, medium, or high tertiles according to their yield of chromosome damage. Age adjusted tertile rankings were used to estimate cancer risk and results were compared with values obtained using traditional modeling approaches. Individual tertile rankings increased after space flight and analysis of follow up samples indicated that the tertile rankings remained in the high category for more than 50% of the individuals assessed so far. Crewmembers that shift and remain in the high category are projected to have increased life-time cancer risk.

The effects of shockwave profile shape and shock obliquity on spallation in Cu and Ta: kinetic and stress-state effects on damage evolution(u)

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

Gray, George T

2010-12-14

Widespread research over the past five decades has provided a wealth of experimental data and insight concerning shock hardening and the spallation response of materials subjected to square-topped shock-wave loading profiles. Less quantitative data have been gathered on the effect of direct, in-contact, high explosive (HE)-driven Taylor wave (or triangular-wave) loading profile shock loading on the shock hardening, damage evolution, or spallation response of materials. Explosive loading induces an impulse dubbed a 'Taylor Wave'. This is a significantly different loading history than that achieved by a square-topped impulse in terms of both the pulse duration at a fixed peak pressure,more » and a different unloading strain rate from the peak Hugoniot state achieved. The goal of this research is to quantify the influence of shockwave obliquity on the spallation response of copper and tantalum by subjecting plates of each material to HE-driven sweeping detonation-wave loading and quantify both the wave propagation and the post-mortem damage evolution. This talk will summarize our current understanding of damage evolution during sweeping detonation-wave spallation loading in Cu and Ta and show comparisons to modeling simulations. The spallation responses of Cu and Ta are both shown to be critically dependent on the shockwave profile and the stress-state of the shock. Based on variations in the specifics of the shock drive (pulse shape, peak stress, shock obliquity) and sample geometry in Cu and Ta, 'spall strength' varies by over a factor of two and the details of the mechanisms of the damage evolution is seen to vary. Simplistic models of spallation, such as P{sub min} based on 1-D square-top shock data lack the physics to capture the influence of kinetics on damage evolution such as that operative during sweeping detonation loading. Such considerations are important for the development of predictive models of damage evolution and spallation in metals and alloys.« less

KSC Tech Transfer News, Volume 2, No. 2

NASA Technical Reports Server (NTRS)

Makufka, David (Editor); Dunn, Carol (Editor)

2009-01-01

This issue contains articles about: (1) the Innovative Partnerships Program (IPP) and the manager of the program, Alexis Hongamen, (2) New Technology Report (NTR) on a Monte Carlo Simulation to Estimate the Likelihood of Direct Lightning Strikes, (3) Kennedy Space Center's Applied Physics Lab, (4) a virtual ruler that is used for many applications, (5) a portable device that finds low-level leaks, (6) a sun-shield, that supports in-space cryogenic propellant storage, (7) lunar dust modeling software, (8) space based monitoring of radiation damage to DNA, (9) the use of light-emitting diode (LED) arrays vegetable production system, (10) Dust Tolerant Intelligent Electrical Connection Systems, (11) Ice Detection Camera System Upgrade, (12) Repair Techniques for Composite Structures, (13) Cryogenic Orbital Testbed, and (14) copyright protection.

77 FR 34876 - Airworthiness Directives; The Boeing Company

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-12

... (a flammable fluid leakage zone) or heat damage to the APU power feeder cable, insulation blankets... heat damage to the APU power feeder cable, insulation blankets, or pressure bulkhead. Relevant Service... feeder cable and heat damage of the insulation blanket adjacent to the clamp, a detailed inspection for...

77 FR 4646 - Airworthiness Directives; Bombardier, Inc. Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-31

...), damage due to sharp bends and kinking or deterioration, insulation cracking, evidence of heat damage to the insulation, and chafing. The unsafe condition is the loss of ice protection systems for the angle... heat damage to the insulation, and chafing) and do all applicable repairs, in accordance with the...

78 FR 47581 - Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-06

... turbine disc. We are proposing this AD to prevent disc cracking, uncontained 2nd-stage turbine blade..., possibly resulting in uncontained second stage turbine blade release with consequent damage to, and reduced...-stage turbine blade release, damage to the engine, and damage to the helicopter. (e) Actions and...

Effects of fire damage on the structural properties of steel bridge elements.

DOT National Transportation Integrated Search

2011-04-30

It is well known that fire can cause severe damage to steel bridges. There are documented cases where fire has directly led to the collapse or significant sagging of a steel bridge. However, when the damage is less severe, the effects of the fire, if...

77 FR 26156 - Airworthiness Directives; Cessna Aircraft Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-03

... surrounding components (wheel base, side rim, lock ring) for damage (such as corrosion, cracks, dents, bent areas, damaged or missing paint or primer, or wear on the metal), and of the bearing cup for corrosion... and surrounding components (wheel base, side rim, lock ring) for damage (such as corrosion, cracks...

The MERINOVA project: MEteorological RIsks as drivers of environmental inNOvation in Agro-ecosystem management

NASA Astrophysics Data System (ADS)

Gobin, Anne; Van de vijver, Hans; Zamani, Sepideh; Curnel, Yannick; Planchon, Viviane; Verspecht, Ann; Van Huylenbroeck, Guido

2014-05-01

Devastating weather-related events have captured the interest of the general public in Belgium. Extreme weather events such as droughts, heat waves and rain storms are projected to increase both in frequency and magnitude with climate change. Since more than half of the Belgian territory is managed by the agricultural sector, extreme events may have significant impacts on agro-ecosystem services and pose severe limitations to sustainable agricultural land management. The research hypothesis of the MERINOVA project is that meteorological risks act as drivers of environmental innovation in agro-ecosystem management. The major objectives are to characterise extreme meteorological events, assess the impact on Belgian agro-ecosystems, characterise their vulnerability and resilience to these events, and explore innovative adaptation options to agricultural risk management. The project comprises of five major parts that reflect the chain of risks: the hazard, its impact on different agro-ecosystems, vulnerability, risk management and risk communication. Impacts developed from physically based models not only provide information on the state of the damage at any given time, but also assist in understanding the links between different factors causing damage and determining bio-physical vulnerability. Socio-economic impacts enlarge the basis for vulnerability mapping, risk management and adaptation options. The perspective of rising risk-exposure is exacerbated further by more limits to aid received for agricultural damage and an overall reduction of direct income support to farmers. The main findings of each of these project building blocks will be communicated. MERINOVA provides for a robust and flexible framework by demonstrating its performance across Belgian agro-ecosystems, and by ensuring its relevance to policy makers and practitioners. A strong expert and end-user network is established to help disseminating and exploiting project results to meet user needs. The research is funded by the Belgian Science Policy Organisation (Belspo) under contract nr SD/RI/03A. https://merinova.vito.be

Biophysical and medical safety basis of laser emission

NASA Astrophysics Data System (ADS)

Paltsev, Yu.; Levina, A.

1996-01-01

Laser equipment may inflict serious losses to human health if safety norms established by relevant standards and other documentation are not properly observed. It is explained by physical properties of laser emission (LE) which differs from general light sources by quantitative behavior of such parameters as the degrees of coherence, monochromaticity, brightness, polarization. Thus, biological effects due to laser emission, as a rule, are more expressed comparing with other types of emission from other spontaneous light sources. LE effects biological tissues through the density of energy flow and impulse duration. It is common knowledge nowadays that LE biological action is assessed by two criteria: physical parameters and absorptive properties of tissues exposed to rays. LE causes the greatest danger to the eyes due to their specific structure. The next target organ vulnerable to LE is skin. Pathological changes of skin depend on the LE power, time of exposure, wave length, and the extent of skin pigmentation. Along with different kinds of damage directly in the tissues exposed to rays, LE may cause changes in organs and body systems subject to indirect exposure. It is important that these changes may develop due to low intensity levels of LE that do not cause local damage. National and international standards on LE safety are based on maximum allowable levels (MAL) of exposure. It has been generally accepted that the main MAL criterion is LE threshold minimal exposure which causes damage to retina, eyes, and skin. As distinct from foreign safety standards, hygienic norms and regulations are in force in the Russian Federation where additional co-efficients along with standard generally accepted MAL values have been introduced for the persons who are subject to occupational regular exposure to lasers. This approach has been chosen after the results of follow-up and health studies of these occupational contingents have been analyzed, and experiments on laboratory animals assessed.

[Increasing oxidative stress in aging].

PubMed

Shimosawa, Tatsuo

2005-06-01

The balance between reactive oxigen species (ROS) production and degradation is important in defining oxidative stress. In aging process, ROS production increases and degradation is impaired and thus oxidative stress is accumulated. Oxidative stress damages organs both directly and indirectly. Protein, lipid, as well as DNA are directly react with ROS, more over, ROS interact with intracellular signaling system. It is reported that several transcription factors such as NF-kappaB, AP-1 and ASK-1 and also it interferes MAPK activity. Besides these signaling, we recently showed that insulin resistance is induced by accumulated oxidative stress in aged mice. Adrenomedullin deficient mice accumulate higher oxidative stress and insulin resistance developed in aging. Oxidative stress in aging relates not only direct organ damage but also induce risk factors for vascular damage such as metabolic syndrome.

Rotor damage detection by using piezoelectric impedance

NASA Astrophysics Data System (ADS)

Qin, Y.; Tao, Y.; Mao, Y. F.

2016-04-01

Rotor is a core component of rotary machinery. Once the rotor has the damage, it may lead to a major accident. Thus the quantitative rotor damage detection method based on piezoelectric impedance is studied in this paper. With the governing equation of piezoelectric transducer (PZT) in a cylindrical coordinate, the displacement along the radius direction is derived. The charge of PZT is calculated by the electric displacement. Then, by the use of the obtained displacement and charge, an analytic piezoelectric impedance model of the rotor is built. Given the circular boundary condition of a rotor, annular elements are used as the analyzed objects and spectral element method is used to set up the damage detection model. The Electro-Mechanical (E/M) coupled impedance expression of an undamaged rotor is deduced with the application of a low-cost impedance test circuit. A Taylor expansion method is used to obtain the approximate E/M coupled impedance expression for the damaged rotor. After obtaining the difference between the undamaged and damaged rotor impedance, a rotor damage detection method is proposed. This method can directly calculate the change of bending stiffness of the structural elements, it follows that the rotor damage can be effectively detected. Finally, a preset damage configuration is used for the numerical simulation. The result shows that the quantitative damage detection algorithm based on spectral element method and piezoelectric impedance proposed in this paper can identify the location and the severity of the damaged rotor accurately.

Practical implementation of the double linear damage rule and damage curve approach for treating cumulative fatigue damage

NASA Technical Reports Server (NTRS)

Manson, S. S.; Halford, G. R.

1980-01-01

Simple procedures are presented for treating cumulative fatigue damage under complex loading history using either the damage curve concept or the double linear damage rule. A single equation is provided for use with the damage curve approach; each loading event providing a fraction of damage until failure is presumed to occur when the damage sum becomes unity. For the double linear damage rule, analytical expressions are provided for determining the two phases of life. The procedure involves two steps, each similar to the conventional application of the commonly used linear damage rule. When the sum of cycle ratios based on phase 1 lives reaches unity, phase 1 is presumed complete, and further loadings are summed as cycle ratios on phase 2 lives. When the phase 2 sum reaches unity, failure is presumed to occur. No other physical properties or material constants than those normally used in a conventional linear damage rule analysis are required for application of either of the two cumulative damage methods described. Illustrations and comparisons of both methods are discussed.

Practical implementation of the double linear damage rule and damage curve approach for treating cumulative fatigue damage

NASA Technical Reports Server (NTRS)

Manson, S. S.; Halford, G. R.

1981-01-01

Simple procedures are given for treating cumulative fatigue damage under complex loading history using either the damage curve concept or the double linear damage rule. A single equation is given for use with the damage curve approach; each loading event providing a fraction of damage until failure is presumed to occur when the damage sum becomes unity. For the double linear damage rule, analytical expressions are given for determining the two phases of life. The procedure comprises two steps, each similar to the conventional application of the commonly used linear damage rule. Once the sum of cycle ratios based on Phase I lives reaches unity, Phase I is presumed complete, and further loadings are summed as cycle ratios based on Phase II lives. When the Phase II sum attains unity, failure is presumed to occur. It is noted that no physical properties or material constants other than those normally used in a conventional linear damage rule analysis are required for application of either of the two cumulative damage methods described. Illustrations and comparisons are discussed for both methods.

Radiation Physics for Space and High Altitude Air Travel

NASA Technical Reports Server (NTRS)

Cucinotta, F. A.; Wilson, J. W.; Goldhagen, P.; Saganti, P.; Shavers, M. R.; McKay, Gordon A. (Technical Monitor)

2000-01-01

Galactic cosmic rays (GCR) are of extra-solar origin consisting of high-energy hydrogen, helium, and heavy ions. The GCR are modified by physical processes as they traverse through the solar system, spacecraft shielding, atmospheres, and tissues producing copious amounts of secondary radiation including fragmentation products, neutrons, mesons, and muons. We discuss physical models and measurements relevant for estimating biological risks in space and high-altitude air travel. Ambient and internal spacecraft computational models for the International Space Station and a Mars mission are discussed. Risk assessment is traditionally based on linear addition of components. We discuss alternative models that include stochastic treatments of columnar damage by heavy ion tracks and multi-cellular damage following nuclear fragmentation in tissue.

Analysis and Characterization of Damage Utilizing an Orthotropic Generalized Composite Material Model Suitable for Use in Impact Problems

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Hoffarth, Canio; Rajan, Subramaniam; Blankenhorn, Gunther

2016-01-01

The need for accurate material models to simulate the deformation, damage and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased usage in the aerospace and automotive communities. In order to address a series of issues identified by the aerospace community as being desirable to include in a next generation composite impact model, an orthotropic, macroscopic constitutive model incorporating both plasticity and damage suitable for implementation within the commercial LS-DYNA computer code is being developed. The plasticity model is based on extending the Tsai-Wu composite failure model into a strain hardening-based orthotropic plasticity model with a non-associative flow rule. The evolution of the yield surface is determined based on tabulated stress-strain curves in the various normal and shear directions and is tracked using the effective plastic strain. To compute the evolution of damage, a strain equivalent semi-coupled formulation is used in which a load in one direction results in a stiffness reduction in multiple material coordinate directions. A detailed analysis is carried out to ensure that the strain equivalence assumption is appropriate for the derived plasticity and damage formulations that are employed in the current model. Procedures to develop the appropriate input curves for the damage model are presented and the process required to develop an appropriate characterization test matrix is discussed

Analysis and Characterization of Damage Utilizing an Orthotropic Generalized Composite Material Model Suitable for Use in Impact Problems

NASA Technical Reports Server (NTRS)

Goldberg, Robert K.; Carney, Kelly S.; DuBois, Paul; Hoffarth, Canio; Rajan, Subramaniam; Blankenhorn, Gunther

2016-01-01

The need for accurate material models to simulate the deformation, damage and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased usage in the aerospace and automotive communities. In order to address a series of issues identified by the aerospace community as being desirable to include in a next generation composite impact model, an orthotropic, macroscopic constitutive model incorporating both plasticity and damage suitable for implementation within the commercial LS-DYNA computer code is being developed. The plasticity model is based on extending the Tsai-Wu composite failure model into a strain hardening-based orthotropic plasticity model with a non-associative flow rule. The evolution of the yield surface is determined based on tabulated stress-strain curves in the various normal and shear directions and is tracked using the effective plastic strain. To compute the evolution of damage, a strain equivalent semi-coupled formulation is used in which a load in one direction results in a stiffness reduction in multiple material coordinate directions. A detailed analysis is carried out to ensure that the strain equivalence assumption is appropriate for the derived plasticity and damage formulations that are employed in the current model. Procedures to develop the appropriate input curves for the damage model are presented and the process required to develop an appropriate characterization test matrix is discussed.

Hormesis does not make sense except in the light of TOR-driven aging

PubMed Central

Blagosklonny, Mikhail V.

2011-01-01

Weak stresses (including weak oxidative stress, cytostatic agents, heat shock, hypoxia, calorie restriction) may extend lifespan. Known as hormesis, this is the most controversial notion in gerontology. For one, it is believed that aging is caused by accumulation of molecular damage. If so, hormetic stresses (by causing damage) must shorten lifespan. To solve the paradox, it was suggested that, by activating repair, hormetic stresses eventually decrease damage. Similarly, Baron Munchausen escaped from a swamp by pulling himself up by his own hair. Instead, I discuss that aging is not caused by accumulation of molecular damage. Although molecular damage accumulates, organisms do not live long enough to age from this accumulation. Instead, aging is driven by overactivated signal-transduction pathways including the TOR (Target of Rapamycin) pathway. A diverse group of hormetic conditions can be divided into two groups. “Hormesis A” inhibits the TOR pathway. “Hormesis B” increases aging-tolerance, defined as the ability to survive catastrophic complications of aging. Hormesis A includes calorie restriction, resveratrol, rapamycin, p53-inducing agents and, in part, physical exercise, heat shock and hypoxia. Hormesis B includes ischemic preconditioning and, in part, physical exercise, heat shock, hypoxia and medical interventions. PMID:22166724

Damage effect and mechanism of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

NASA Astrophysics Data System (ADS)

Xiao-Wen, Xi; Chang-Chun, Chai; Gang, Zhao; Yin-Tang, Yang; Xin-Hai, Yu; Yang, Liu

2016-04-01

The damage effect and mechanism of the electromagnetic pulse (EMP) on the GaAs pseudomorphic high electron mobility transistor (PHEMT) are investigated in this paper. By using the device simulation software, the distributions and variations of the electric field, the current density and the temperature are analyzed. The simulation results show that there are three physical effects, i.e., the forward-biased effect of the gate Schottky junction, the avalanche breakdown, and the thermal breakdown of the barrier layer, which influence the device current in the damage process. It is found that the damage position of the device changes with the amplitude of the step voltage pulse. The damage appears under the gate near the drain when the amplitude of the pulse is low, and it also occurs under the gate near the source when the amplitude is sufficiently high, which is consistent with the experimental results. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900), and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

Understanding the Femtosecond Laser-Solid Interaction Near and Beyond the Material Damage Threshold

DTIC Science & Technology

2016-05-23

study of the fundamentals of femtosecond laser damage as a function of various parameters, laser wavelength, pulsewidth, pulse number, experimental ... experimental observation without any free parameters. The brand new FSD Lab constructed under the BRI grant in the Physics Research Building at the Ohio... studied across a range of band-gaps for s- and p-polarized light and it is found that conventional theoretical prediction on laser damage threshold

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure.

PubMed

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-05-11

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures.

On-Line Multi-Damage Scanning Spatial-Wavenumber Filter Based Imaging Method for Aircraft Composite Structure

PubMed Central

Ren, Yuanqiang; Qiu, Lei; Yuan, Shenfang; Bao, Qiao

2017-01-01

Structural health monitoring (SHM) of aircraft composite structure is helpful to increase reliability and reduce maintenance costs. Due to the great effectiveness in distinguishing particular guided wave modes and identifying the propagation direction, the spatial-wavenumber filter technique has emerged as an interesting SHM topic. In this paper, a new scanning spatial-wavenumber filter (SSWF) based imaging method for multiple damages is proposed to conduct on-line monitoring of aircraft composite structures. Firstly, an on-line multi-damage SSWF is established, including the fundamental principle of SSWF for multiple damages based on a linear piezoelectric (PZT) sensor array, and a corresponding wavenumber-time imaging mechanism by using the multi-damage scattering signal. Secondly, through combining the on-line multi-damage SSWF and a PZT 2D cross-shaped array, an image-mapping method is proposed to conduct wavenumber synthesis and convert the two wavenumber-time images obtained by the PZT 2D cross-shaped array to an angle-distance image, from which the multiple damages can be directly recognized and located. In the experimental validation, both simulated multi-damage and real multi-damage introduced by repeated impacts are performed on a composite plate structure. The maximum localization error is less than 2 cm, which shows good performance of the multi-damage imaging method. Compared with the existing spatial-wavenumber filter based damage evaluation methods, the proposed method requires no more than the multi-damage scattering signal and can be performed without depending on any wavenumber modeling or measuring. Besides, this method locates multiple damages by imaging instead of the geometric method, which helps to improve the signal-to-noise ratio. Thus, it can be easily applied to on-line multi-damage monitoring of aircraft composite structures. PMID:28772879

Nanodosimetric track structure in homogeneous extended beams.

PubMed

Conte, V; Moro, D; Colautti, P; Grosswendt, B

2015-09-01

Physical aspects of particle track structure are important in determining the induction of clustered damage in relevant subcellular structures like the DNA and higher-order genomic structures. The direct measurement of track-structure properties of ionising radiation is feasible today by counting the number of ionisations produced inside a small gas volume. In particular, the so-called track-nanodosimeter, installed at the TANDEM-ALPI accelerator complex of LNL, measures ionisation cluster-size distributions in a simulated subcellular structure of dimensions 20 nm, corresponding approximately to the diameter of the chromatin fibre. The target volume is irradiated by pencil beams of primary particles passing at specified impact parameter. To directly relate these measured track-structure data to radiobiological measurements performed in broad homogeneous particle beams, these data can be integrated over the impact parameter. This procedure was successfully applied to 240 MeV carbon ions and compared with Monte Carlo simulations for extended fields. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Mutation Directs the Structural Switch of DNA Binding Proteins under Starvation to a Ferritin-like Protein Cage.

PubMed

Williams, Sunanda Margrett; Chandran, Anu Vijayakumari; Prakash, Sunita; Vijayan, Mamannamana; Chatterji, Dipankar

2017-09-05

Proteins of the ferritin family are ubiquitous in living organisms. With their spherical cage-like structures they are the iron storehouses in cells. Subfamilies of ferritins include 24-meric ferritins and bacterioferritins (maxiferritins), and 12-meric Dps (miniferritins). Dps safeguards DNA by direct binding, affording physical protection and safeguards from free radical-mediated damage by sequestering iron in its core. The maxiferritins can oxidize and store iron but cannot bind DNA. Here we show that a mutation at a critical interface in Dps alters its assembly from the canonical 12-mer to a ferritin-like 24-mer under crystallization. This structural switch was attributed to the conformational alteration of a highly conserved helical loop and rearrangement of the C-terminus. Our results demonstrate a novel concept of mutational switch between related protein subfamilies and corroborate the popular model for evolution by which subtle substitutions in an amino acid sequence lead to diversification among proteins. Copyright © 2017 Elsevier Ltd. All rights reserved.

A self-harm series and its relationship with childhood adversity among adolescents in mainland China: a cross-sectional study.

PubMed

Han, Azhu; Wang, Gengfu; Xu, Geng; Su, Puyu

2018-02-01

Self-harm (SH) is an emerging problem among Chinese adolescents. The present study aimed to measure the prevalence of SH behaviours and to explore the relationship between childhood adversity and different SH subtypes among Chinese adolescents. A total of 5726 middle school students were randomly selected in three cities of Anhui province, China, using a stratified cluster sampling method. SH was categorized into five subtypes (highly lethal self-harm, less lethal self-harm with visible tissue damage, self-harm without visible tissue damage, self-harmful behaviours with latency damage and psychological self-harm). Multivariate logistic regression was used to explore the relationships between childhood adversity and different subtypes of adolescent SH. The prevalence rates of highly lethal self-harm, less lethal self-harm with visible tissue damage, self-harm without visible tissue damage, self-harmful behaviours with latency damage and psychological self-harm were 6.1, 20.4, 32.0, 20.0 and 23.0%, respectively. Childhood sexual abuse and physical peer victimization were associated with each SH subtype with adjusted odds ratios (AORs) ranging from 1.23 to 1.76. Highly lethal self-harm was associated with childhood physical peer victimization, sexual abuse, emotional abuse, and emotional neglect. The less lethal SH subtypes (i.e., less lethal self-harm with visible tissue damage, self-harm without visible tissue damage, self-harmful behaviours with latency damage and psychological self-harm) were associated with childhood peer victimization, family life stress event scores and childhood sexual abuse. A high prevalence of SH exists among Chinese adolescents. The association of childhood adversity with SH merits serious attention in both future research and preventive interventions.

Chromatin relaxation-mediated induction of p19INK4d increases the ability of cells to repair damaged DNA.

PubMed

Ogara, María F; Sirkin, Pablo F; Carcagno, Abel L; Marazita, Mariela C; Sonzogni, Silvina V; Ceruti, Julieta M; Cánepa, Eduardo T

2013-01-01

The maintenance of genomic integrity is of main importance to the survival and health of organisms which are continuously exposed to genotoxic stress. Cells respond to DNA damage by activating survival pathways consisting of cell cycle checkpoints and repair mechanisms. However, the signal that triggers the DNA damage response is not necessarily a direct detection of the primary DNA lesion. In fact, chromatin defects may serve as initiating signals to activate those mechanisms. If the modulation of chromatin structure could initiate a checkpoint response in a direct manner, this supposes the existence of specific chromatin sensors. p19INK4d, a member of the INK4 cell cycle inhibitors, plays a crucial role in regulating genomic stability and cell viability by enhancing DNA repair. Its expression is induced in cells injured by one of several genotoxic treatments like cis-platin, UV light or neocarzinostatin. Nevertheless, when exogenous DNA damaged molecules are introduced into the cell, this induction is not observed. Here, we show that p19INK4d is enhanced after chromatin relaxation even in the absence of DNA damage. This induction was shown to depend upon ATM/ATR, Chk1/Chk2 and E2F activity, as is the case of p19INK4d induction by endogenous DNA damage. Interestingly, p19INK4d improves DNA repair when the genotoxic damage is caused in a relaxed-chromatin context. These results suggest that changes in chromatin structure, and not DNA damage itself, is the actual trigger of p19INK4d induction. We propose that, in addition to its role as a cell cycle inhibitor, p19INK4d could participate in a signaling network directed to detecting and eventually responding to chromatin anomalies.

Three-dimensional Model of Tissue and Heavy Ions Effects

NASA Technical Reports Server (NTRS)

Ponomarev, Artem L.; Sundaresan, Alamelu; Huff, Janice L.; Cucinotta, Francis A.

2007-01-01

A three-dimensional tissue model was incorporated into a new Monte Carlo algorithm that simulates passage of heavy ions in a tissue box . The tissue box was given as a realistic model of tissue based on confocal microscopy images. The action of heavy ions on the cellular matrix for 2- or 3-dimensional cases was simulated. Cells were modeled as a cell culture monolayer in one example, where the data were taken directly from microscopy (2-d cell matrix), and as a multi-layer obtained from confocal microscopy (3-d case). Image segmentation was used to identify cells with precise areas/volumes in an irradiated cell culture monolayer, and slices of tissue with many cell layers. The cells were then inserted into the model box of the simulated physical space pixel by pixel. In the case of modeled tissues (3-d), the tissue box had periodic boundary conditions imposed, which extrapolates the technique to macroscopic volumes of tissue. For the real tissue (3-d), specific spatial patterns for cell apoptosis and necrosis are expected. The cell patterns were modeled based on action cross sections for apoptosis and necrosis estimated from current experimental data. A spatial correlation function indicating a higher spatial concentration of damaged cells from heavy ions relative to the low-LET radiation cell damage pattern is presented. The spatial correlation effects among necrotic cells can help studying microlesions in organs, and probable effects of directionality of heavy ion radiation on epithelium and endothelium.

Improved photoacoustic dosimetry for retinal laser surgery

NASA Astrophysics Data System (ADS)

Dufour, Suzie; Brown, Robert B.; Gallant, Pascal; Mermut, Ozzy

2018-02-01

Lasers are employed for numerous medical interventions by exploiting ablative, disruptive or thermal effects. In ocular procedures, lasers have been used for decades to treat diseases such as diabetic retinopathy, macular edema and aged related macular degeneration via photocoagulation of retinal tissues. Although laser photocoagulation is well established in today's practice, efforts to improve clinical outcomes by reducing the collateral damage from thermal diffusion is leading to novel treatments using shorter (μs) laser pulses (e.g. selective retinal therapy) which result in physical rather than thermal damage. However, for these new techniques to be widely utilized, a method is required to ensure safe but sufficient dosage has been applied, since no visible effects can be seen by ophthalmoscopy directly post treatment. Photoacoustic feedback presents an attractive solution, as the signal is dependent directly on absorbed dosage. Here, we present a method that takes advantage of temporal pulse formatting technology to minimize variation in absorbed dose in ophthalmic laser treatment and provide intelligent dosimetry feedback based on photoacoustic (PA) response. This method tailors the pulse to match the frequency response of the sample and/or detection chain. Depending on the system, this may include the absorbing particle size, the laser beam diameter, the laser pulse duration, tissue acoustic properties and the acoustic detector frequency response. A significant improvement (<7x) of photoacoustic signal-to-noise ratio over equivalent traditional pulse formats have been achieved, while spectral analysis of the detected signal provides indications of cavitation events and other sample properties.

Asymmetrical perception of body rotation after unilateral injury to human vestibular cortex.

PubMed

Philbeck, John W; Behrmann, Marlene; Biega, Tim; Levy, Lucien

2006-01-01

Vestibular information plays a key role in many perceptual and cognitive functions, but surprisingly little is known about how vestibular signals are processed at the cortical level in humans. To address this issue, we tested the ability of two patients, with damage to key components of the vestibular network in either the left or right hemisphere, to perceive passive whole-body rotations (25-125 degrees) about the yaw axis. In both patients, the posterior insula, hippocampus, putamen, and thalamus were extensively damaged. The patients' responses were compared with those of nine age- and sex-matched neurologically intact participants. The body rotations were conducted without vision and the peak angular velocities ranged from 40 degrees to 90 degrees per second. Perceived rotation was assessed by open-loop manual pointing. The right hemisphere patient exhibited poor sensitivity for body rotations toward the contralesional (left) hemispace and generally underestimated the rotations. By contrast, his judgments of rotations toward the ipsilesional (right) hemispace greatly overestimated the physical rotation by 50-70 degrees for all tested magnitudes. The left hemisphere patient's responses were more appropriately scaled for both rotation directions, falling in the low-normal range. These findings suggest that there is some degree of hemispheric specialization in the cortical processing of dynamic head rotations in the yaw plane. In this view, right hemisphere structures play a dominant role, processing rotations in both directions, while left hemisphere structures process rotations only toward the contralesional hemispace.

Data search and environmental hazard assessment for post-seveso chemicals

NASA Astrophysics Data System (ADS)

Blok, Johan; Oostergo, Herman D.; Wondergem, Abraham C.; Leeuwen, Cornelis J. V.

1992-05-01

After the serious accident with a chemical industrial plant at Seveso (Italy) in 1976, the Commission of the European Communities has made a directive on major accidents, usually called the Post-Seveso Guideline. In its annex III, a list of 178 substances is given for which potentially dangerous volumes in case of an accident are defined on the basis of human health criteria. For the implementation of environmental criteria, information on toxicity to aquatic organisms, dilution, and physical behavior in water is needed. A literature search for relevant data on these 178 substances revealed aquatic toxicity data for 116 substances, but only for 87 substances sufficient data were available to make a hazard assessment. As an example, the River Rhine was used to calculate the critical quantities that, after a sudden discharge in the Swiss part, could cause damage at the Dutch part some 800 km downstream. In the absence of a common opinion on the criteria for being a major accident and a serious environmental hazard, the impact of different criteria quantities is discussed. If, for example, in the whole River Rhine a mortality of 5% of the aquatic species is chosen as the criterion for damage to the ecosystem, the critical quantities as mentioned in the EEC directive have to be lowered drastically for the majority of the substances. For 18 substances it could be shown that release of the mentioned quantities would be catastrophic for aquatic life in the whole river.

Calculation on spectrum of direct DNA damage induced by low-energy electrons including dissociative electron attachment.

PubMed

Liu, Wei; Tan, Zhenyu; Zhang, Liming; Champion, Christophe

2017-03-01

In this work, direct DNA damage induced by low-energy electrons (sub-keV) is simulated using a Monte Carlo method. The characteristics of the present simulation are to consider the new mechanism of DNA damage due to dissociative electron attachment (DEA) and to allow determining damage to specific bases (i.e., adenine, thymine, guanine, or cytosine). The electron track structure in liquid water is generated, based on the dielectric response model for describing electron inelastic scattering and on a free-parameter theoretical model and the NIST database for calculating electron elastic scattering. Ionization cross sections of DNA bases are used to generate base radicals, and available DEA cross sections of DNA components are applied for determining DNA-strand breaks and base damage induced by sub-ionization electrons. The electron elastic scattering from DNA components is simulated using cross sections from different theoretical calculations. The resulting yields of various strand breaks and base damage in cellular environment are given. Especially, the contributions of sub-ionization electrons to various strand breaks and base damage are quantitatively presented, and the correlation between complex clustered DNA damage and the corresponding damaged bases is explored. This work shows that the contribution of sub-ionization electrons to strand breaks is substantial, up to about 40-70%, and this contribution is mainly focused on single-strand break. In addition, the base damage induced by sub-ionization electrons contributes to about 20-40% of the total base damage, and there is an evident correlation between single-strand break and damaged base pair A-T.

Child Abuse

MedlinePlus

... puts a child at risk of harm. Child abuse can be physical, sexual or emotional. Neglect, or not providing for a child's needs, is also a form of abuse. Most abused children suffer greater emotional than physical damage. An abused child may become ...

Evaluating experimental molecular physics studies of radiation damage in DNA*

NASA Astrophysics Data System (ADS)

Śmiałek, Małgorzata A.

2016-11-01

The field of Atomic and Molecular Physics (AMP) is a mature field exploring the spectroscopy, excitation, ionisation of atoms and molecules in all three phases. Understanding of the spectroscopy and collisional dynamics of AMP has been fundamental to the development and application of quantum mechanics and is applied across a broad range of disparate disciplines including atmospheric sciences, astrochemistry, combustion and environmental science, and in central to core technologies such as semiconductor fabrications, nanotechnology and plasma processing. In recent years the molecular physics also started significantly contributing to the area of the radiation damage at molecular level and thus cancer therapy improvement through both experimental and theoretical advances, developing new damage measurement and analysis techniques. It is therefore worth to summarise and highlight the most prominent findings from the AMP community that contribute towards better understanding of the fundamental processes in biologically-relevant systems as well as to comment on the experimental challenges that were met for more complex investigation targets. Contribution to the Topical Issue "Low-Energy Interactions related to Atmospheric and Extreme Conditions", edited by S. Ptasinska, M. Smialek-Telega, A. Milosavljevic, B. Sivaraman.

Seedling mortality in Hawaiian rain forest: The role of small-scale physical disturbance

USGS Publications Warehouse

Drake, D.R.; Pratt, L.W.

2001-01-01

Most montane rain forests on the island of Hawaii consist of a closed canopy formed by Cibotium spp. tree ferns beneath an open canopy of emergent Metrosideros polymorpha trees. We used artificial seedlings to assess the extent to which physical disturbance caused by the senescing fronds of tree ferns and the activities of feral pigs might limit tree regeneration. Artificial seedlings were established terrestrially (N = 300) or epiphytically (N = 300) on tree fern stems. Half of the seedlings on each substrate were in an exclosure lacking feral pigs and half were in forest with pigs present. After one year, the percentage of seedlings damaged was significantly greater among terrestrial seedlings (25.7%) than epiphytic seedlings (11.3%). Significantly more terrestrial seedlings were damaged in the presence of pigs (31.3%) than in the absence of pigs (20.0%). Senescing fronds of tree ferns were responsible for 60.3 percent of the damaged seedlings. Physical disturbance is potentially a major cause of seedling mortality and may reduce the expected half-life of a seedling cohort to less than two years.

GENETIC DAMAGE INDICATORS IN FISH EXPOSED TO VARYING STREAM CONDITIONS IN AN AGRICULTURAL WATERSHED

EPA Science Inventory

Micronucleus (MN) and single cell gel electrophoresis (SCG) measures of genetic damage in fish erythrocytes were included in an evaluation of a wide range of biological and physical stream condition parameters being developed for use in watershed and regional scale assessments. B...

Implications of Sensory Stimulation in Self-Destructive Behavior.

ERIC Educational Resources Information Center

Edelson, Stephen M.

1984-01-01

The author extends the self stimulatory theory of self destructive behavior in autistic, schizophrenic, and mentally retarded individuals to suggest that damage of the skin's nerve structure lowers the tactile sensory threshold for physical input and enables individuals to obtain sensory stimulation by repeatedly depressing the damaged area. (CL)

Effect of upper extremity nerve damage on activity participation, pain, depression, and quality of life.

PubMed

Bailey, Ryan; Kaskutas, Vicki; Fox, Ida; Baum, Carolyn M; Mackinnon, Susan E

2009-11-01

To explore the relationship between upper extremity nerve damage and activity participation, pain, depression, and perceived quality of life. A total of 49 patients with upper extremity nerve damage completed standardized measures of activity participation, pain, depression, and quality of life. We analyzed scores for all subjects and for 2 diagnostic groups: patients with compressive neuropathy and patients with nerve injury (laceration, tumor, and brachial plexus injury), and explored predictors of overall quality of life. Participants had given up 21% of their previous daily activities; greater activity loss was reported in patients with nerve injury. Pain was moderate and 39% had signs of clinical depression. Physical and psychological quality of life ratings were below the norms. Activity loss was strongly associated with higher levels of depression and lower physical and psychological quality of life. Higher depression scores correlated strongly with lower overall quality of life. Greater pain correlated moderately with higher depression scores and weakly with quality of life; no statistical relationship was found between pain and physical quality of life. Activity participation and depression predicted 61% of the variance in overall quality of life in patients with nerve damage. The results of this study suggest that hand surgeons and therapists caring for patients with nerve compression and nerve injury should discuss strategies to improve activity participation, and decrease pain and depression, to improve overall effect on quality of life throughout the recovery process. Depression screening and referral when indicated should be included in the overall treatment plan for patients with upper extremity nerve damage. Prognostic IV.

Relationship Between Viremia and Specific Organ Damage in Ebola Patients: A Cohort Study.

PubMed

Lanini, Simone; Portella, Gina; Vairo, Francesco; Kobinger, Gary P; Pesenti, Antonio; Langer, Martin; Kabia, Soccoh; Brogiato, Giorgio; Amone, Jackson; Castilletti, Concetta; Miccio, Rossella; Capobianchi, Maria Rosaria; Strada, Gino; Zumla, Alimuddin; Di Caro, Antonino; Ippolito, Giuseppe

2018-01-06

Pathogenesis of Ebola virus disease remains poorly understood. We used concomitant determination of routine laboratory biomarkers and Ebola viremia to explore the potential role of viral replication in specific organ damage. We recruited patients with detectable Ebola viremia admitted to the EMERGENCY Organizzazione Non Governativa Organizzazione Non Lucrativa di Utilità Sociale (ONG ONLUS) Ebola Treatment Center in Sierra Leone. Repeated measure of Ebola viremia, alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), activated prothrombin time (aPTT), international normalized ratio (INR), creatinine, and blood urea nitrogen (BUN) were recorded. Patients were followed up from admission until death or discharge. One hundred patients (49 survivors and 51 nonsurvivors) were included in the analysis. Unadjusted analysis to compare survivors and nonsurvivors provided evidence that all biomarkers were significantly above the normal range and that the extent of these abnormalities was generally higher in nonsurvivors than in survivors. Multivariable mixed-effects models provided strong evidence for a biological gradient (suggestive of a direct role in organ damage) between the viremia levels and either ALT, AST, CPK LDH, aPTT, and INR. In contrast, no direct linear association was found between viremia and either creatinine, BUN, or bilirubin. This study provides evidence to support that Ebola virus may have a direct role in muscular damage and imbalance of the coagulation system. We did not find strong evidence suggestive of a direct role of Ebola virus in kidney damage. The role of the virus in liver damage remains unclear, but our evidence suggests that acute severe liver injury is not a typical feature of Ebola virus disease. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

Biomechanical factors contributing to self-organization in seagrass landscapes

USGS Publications Warehouse

Fonseca, M.S.; Koehl, M.A.R.; Kopp, B.S.

2007-01-01

Field observations have revealed that when water flow is consistently from one direction, seagrass shoots align in rows perpendicular to the primary axis of flow direction. In this study, live Zostera marina shoots were arranged either randomly or in rows perpendicular to the flow direction and tested in a seawater flume under unidirectional flow and waves to determine if shoot arrangement: a) influenced flow-induced force on individual shoots, b) differentially altered water flow through the canopy, and c) influenced light interception by the canopy. In addition, blade breaking strength was compared with flow-induced force to determine if changes in shoot arrangement might reduce the potential for damage to shoots. Under unidirectional flow, both current velocity in the canopy and force on shoots were significantly decreased when shoots were arranged in rows as compared to randomly. However, force on shoots was nearly constant with downstream distance, arising from the trade-off of shoot bending and in-canopy flow reduction. The coefficient of drag was higher for randomly-arranged shoots at low velocities (< 30 cm s- 1) but converged rapidly among the two shoot arrangements at higher velocities. Shoots arranged in rows tended to intercept slightly more light than those arranged randomly. Effects of shoot arrangement under waves were less clear, potentially because we did not achieve the proper plant size?row spacing ratio. At this point, we may only suggest that water motion, as opposed to light capture, is the dominant physical mechanism responsible for these shoot arrangements. Following a computation of the Environmental Stress Factor, we concluded that even photosynthetically active blades may be damaged or broken under frequently encountered storm conditions, irrespective of shoot arrangement. We hypothesize that when flow is generally from one direction, seagrass bed patterns over multiple scales of consideration may arise as a cumulative effect of individual shoot self-organization driven by reduced force and drag on the shoots and somewhat improved light capture.

A brittle star-like robot capable of immediately adapting to unexpected physical damage.

PubMed

Kano, Takeshi; Sato, Eiki; Ono, Tatsuya; Aonuma, Hitoshi; Matsuzaka, Yoshiya; Ishiguro, Akio

2017-12-01

A major challenge in robotic design is enabling robots to immediately adapt to unexpected physical damage. However, conventional robots require considerable time (more than several tens of seconds) for adaptation because the process entails high computational costs. To overcome this problem, we focus on a brittle star-a primitive creature with expendable body parts. Brittle stars, most of which have five flexible arms, occasionally lose some of them and promptly coordinate the remaining arms to escape from predators. We adopted a synthetic approach to elucidate the essential mechanism underlying this resilient locomotion. Specifically, based on behavioural experiments involving brittle stars whose arms were amputated in various ways, we inferred the decentralized control mechanism that self-coordinates the arm motions by constructing a simple mathematical model. We implemented this mechanism in a brittle star-like robot and demonstrated that it adapts to unexpected physical damage within a few seconds by automatically coordinating its undamaged arms similar to brittle stars. Through the above-mentioned process, we found that physical interaction between arms plays an essential role for the resilient inter-arm coordination of brittle stars. This finding will help develop resilient robots that can work in inhospitable environments. Further, it provides insights into the essential mechanism of resilient coordinated motions characteristic of animal locomotion.

A brittle star-like robot capable of immediately adapting to unexpected physical damage

PubMed Central

Sato, Eiki; Ono, Tatsuya; Aonuma, Hitoshi; Matsuzaka, Yoshiya; Ishiguro, Akio

2017-01-01

A major challenge in robotic design is enabling robots to immediately adapt to unexpected physical damage. However, conventional robots require considerable time (more than several tens of seconds) for adaptation because the process entails high computational costs. To overcome this problem, we focus on a brittle star—a primitive creature with expendable body parts. Brittle stars, most of which have five flexible arms, occasionally lose some of them and promptly coordinate the remaining arms to escape from predators. We adopted a synthetic approach to elucidate the essential mechanism underlying this resilient locomotion. Specifically, based on behavioural experiments involving brittle stars whose arms were amputated in various ways, we inferred the decentralized control mechanism that self-coordinates the arm motions by constructing a simple mathematical model. We implemented this mechanism in a brittle star-like robot and demonstrated that it adapts to unexpected physical damage within a few seconds by automatically coordinating its undamaged arms similar to brittle stars. Through the above-mentioned process, we found that physical interaction between arms plays an essential role for the resilient inter-arm coordination of brittle stars. This finding will help develop resilient robots that can work in inhospitable environments. Further, it provides insights into the essential mechanism of resilient coordinated motions characteristic of animal locomotion. PMID:29308250

Structural damage identification using damping: a compendium of uses and features

NASA Astrophysics Data System (ADS)

Cao, M. S.; Sha, G. G.; Gao, Y. F.; Ostachowicz, W.

2017-04-01

The vibration responses of structures under controlled or ambient excitation can be used to detect structural damage by correlating changes in structural dynamic properties extracted from responses with damage. Typical dynamic properties refer to modal parameters: natural frequencies, mode shapes, and damping. Among these parameters, natural frequencies and mode shapes have been investigated extensively for their use in damage characterization by associating damage with reduction in local stiffness of structures. In contrast, the use of damping as a dynamic property to represent structural damage has not been comprehensively elucidated, primarily due to the complexities of damping measurement and analysis. With advances in measurement technologies and analysis tools, the use of damping to identify damage is becoming a focus of increasing attention in the damage detection community. Recently, a number of studies have demonstrated that damping has greater sensitivity for characterizing damage than natural frequencies and mode shapes in various applications, but damping-based damage identification is still a research direction ‘in progress’ and is not yet well resolved. This situation calls for an overall survey of the state-of-the-art and the state-of-the-practice of using damping to detect structural damage. To this end, this study aims to provide a comprehensive survey of uses and features of applying damping in structural damage detection. First, we present various methods for damping estimation in different domains including the time domain, the frequency domain, and the time-frequency domain. Second, we investigate the features and applications of damping-based damage detection methods on the basis of two predominant infrastructure elements, reinforced concrete structures and fiber-reinforced composites. Third, we clarify the influential factors that can impair the capability of damping to characterize damage. Finally, we recommend future research directions for advancing damping-based damage detection. This work holds the promise of (a) helping researchers identify crucial components in damping-based damage detection theories, methods, and technologies, and (b) leading practitioners to better implement damping-based structural damage identification.

77 FR 68711 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-16

... test for indications of corrosion and damage to the bogie assembly base material, and a magnetic particle inspection for cracks, corrosion, and damage of the bogie beam. Corrective actions include...

77 FR 25371 - Transportation of Household Goods in Interstate Commerce; Consumer Protection Regulations...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-30

... services when the shipper agrees to release the carrier from full liability for potential loss and damage... implemented a congressional directive to enhance consumer protection in cases of loss or damage that occur... the estimates they provide to prospective shippers: WARNING: If a moving company loses or damages your...

30 CFR 220.011 - Schedule of allowable direct and allocable joint costs and credits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... household applicances, and purchases of insurance against damages to or loss of personal property are... approval. (h) Damages and losses to NPSL property. All costs necessary for the repair or replacement of NPSL property made necessary because of damages or losses incurred by fire, flood, storm, theft...

77 FR 28328 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

... loose or missing fastener, a crack, damage, or corrosion and adding an internal doubler to the aft shear... proposed actions are intended to detect a loose or missing fastener, a crack, damage, or corrosion on the T... inspection of the T/R pylon ``components and structure for obvious damage, cracks, corrosion, and security...

Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

PubMed

Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

2015-02-01

Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Probabilistic Fatigue Damage Prognosis Using a Surrogate Model Trained Via 3D Finite Element Analysis

NASA Technical Reports Server (NTRS)

Leser, Patrick E.; Hochhalter, Jacob D.; Newman, John A.; Leser, William P.; Warner, James E.; Wawrzynek, Paul A.; Yuan, Fuh-Gwo

2015-01-01

Utilizing inverse uncertainty quantification techniques, structural health monitoring can be integrated with damage progression models to form probabilistic predictions of a structure's remaining useful life. However, damage evolution in realistic structures is physically complex. Accurately representing this behavior requires high-fidelity models which are typically computationally prohibitive. In the present work, a high-fidelity finite element model is represented by a surrogate model, reducing computation times. The new approach is used with damage diagnosis data to form a probabilistic prediction of remaining useful life for a test specimen under mixed-mode conditions.

Mechanical Damage Detection of Indonesia Local Citrus Based on Fluorescence Imaging

NASA Astrophysics Data System (ADS)

Siregar, T. H.; Ahmad, U.; Sutrisno; Maddu, A.

2018-05-01

Citrus experienced physical damage in peel will produce essential oils that contain polymethoxylated flavone. Polymethoxylated flavone is fluorescence substance; thus can be detected by fluorescence imaging. This study aims to study the fluorescence spectra characteristic and to determine the damage region in citrus peel based on fluorescence image. Pulung citrus from Batu district, East Java, as a famous citrus production area in Indonesia, was used in the experiment. It was observed that the image processing could detect the mechanical damage region. Fluorescence imaging can be used to classify the citrus into two categories, sound and defect citruses.

Damage characteristics and thermo-physical properties changes of limestone and sandstone during thermal treatment from -30 °C to 1000 °C

NASA Astrophysics Data System (ADS)

Shen, Yanjun; Yang, Yang; Yang, Gengshe; Hou, Xin; Ye, Wanjun; You, Zhemin; Xi, Jiami

2018-05-01

A series of experiments were carried out to measure the damage characteristics of two common sedimentary rocks of limestone and sandstone at temperatures ranging from -30 °C to 1000 °C The apparent thermal conductivity, thermal diffusivity and specific heat capacity were investigated respectively. Then, several discrepancy reasons for the damage characteristics and thermo-physical properties of limestone and sandstone were probed. The results show that water migration and phase transition are two core factors for the frost damage and thermal behaviors improvement during the cooling process(20 °C → -30 °C).The heating process (20 °C → 1000 °C) was divided into three stages of 20 °C → 200 °C, 200 °C → 600 °Cand 600 °C → 1000 °C. The first stage was closely related to pore-water evaporation, and the next two stages were attributed to the thermal reactions of mineral partials. The mineral decomposition tended to be intensified and resulted in the interior damage or even the accelerated degradation of thermal properties until at a threshold temperature of 600 °C. In essential, the structural features and the sensitivity of mineral composition to temperature were two mainly influential factors on the damage effects and heat conduct of the sedimentary rocks during variations in environmental temperature.

Magnetic shield for turbomolecular pump of the Magnetized Plasma Linear Experimental device at Saha Institute of Nuclear Physics.

PubMed

Biswas, Subir; Chattopadhyay, Monobir; Pal, Rabindranath

2011-01-01

The turbo molecular pump of the Magnetized Plasma Linear Experimental device is protected from damage by a magnetic shield. As the pump runs continuously in a magnetic field environment during a plasma physics experiment, it may get damaged owing to eddy current effect. For design and testing of the shield, first we simulate in details various aspects of magnetic shield layouts using a readily available field design code. The performance of the shield made from two half cylinders of soft iron material, is experimentally observed to agree very well with the simulation results.

A Novel Multiscale Physics Based Progressive Failure Methodology for Laminated Composite Structures

NASA Technical Reports Server (NTRS)

Pineda, Evan J.; Waas, Anthony M.; Bednarcyk, Brett A.; Collier, Craig S.; Yarrington, Phillip W.

2008-01-01

A variable fidelity, multiscale, physics based finite element procedure for predicting progressive damage and failure of laminated continuous fiber reinforced composites is introduced. At every integration point in a finite element model, progressive damage is accounted for at the lamina-level using thermodynamically based Schapery Theory. Separate failure criteria are applied at either the global-scale or the microscale in two different FEM models. A micromechanics model, the Generalized Method of Cells, is used to evaluate failure criteria at the micro-level. The stress-strain behavior and observed failure mechanisms are compared with experimental results for both models.

Photopolymerized materials and patterning for improved performance of neural prosthetics

NASA Astrophysics Data System (ADS)

Tuft, Bradley William

Neural prosthetics are used to replace or substantially augment remaining motor and sensory functions of neural pathways that were lost or damaged due to physical trauma, disease, or genetics. However, due to poor spatial signal resolution, neural prostheses fail to recapitulate the intimate, precise interactions inherent to neural networks. Designing materials and interfaces that direct de novo nerve growth to spatially specific stimulating elements is, therefore, a promising method to enhance signal specificity and performance of prostheses such as the successful cochlear implant (CI) and the developing retinal implant. In this work, the spatial and temporal reaction control inherent to photopolymerization was used to develop methods to generate micro and nanopatterned materials that direct neurite growth from prosthesis relevant neurons. In particular, neurite growth and directionality has been investigated in response to physical, mechanical, and chemical cues on photopolymerized surfaces. Spiral ganglion neurons (SGNs) serve as the primary neuronal model as they are the principal target for CI stimulation. The objective of the research is to rationally design materials that spatially direct neurite growth and to translate fundamental understanding of nerve cell-material interactions into methods of nerve regeneration that improve neural prosthetic performance. A rapid, single-step photopolymerization method was developed to fabricate micro and nanopatterned physical cues on methacrylate surfaces by selectively blocking light with photomasks. Feature height is readily tuned by modulating parameters of the photopolymerizaiton including initiator concentration and species, light intensity, separation distance from the photomask, and radiation exposure time. Alignment of neural elements increases significantly with increasing feature amplitude and constant periodicity, as well as with decreasing periodicity and constant amplitude. SGN neurite alignment strongly correlates with the maximum feature slope. Neurite alignment is compared on unpatterned, unidirectional, and multidirectional photopolymerized micropatterns. The effect of substrate rigidity on neurite alignment to physical cues was determined by maintaining equivalent pattern microfeatures, afforded by the reaction control of photopolymerization, while concomitantly altering the composition of several copolymer platforms to tune matrix stiffness. For each platform, neurite alignment to unidirectional patterns increases with increasing substrate rigidity. Interestingly, SGN neurites respond to material stiffness cues that are orders of magnitude higher (GPa) than what is typically ascribed to neural environments (kPa). Finally, neurite behavior at bioactive borders of various adhesion modulating molecules was evaluated on micropatterned materials to determine which cues took precedence in establishing neurite directionality. At low microfeatures aspect ratios, neurites align to the pattern direction but are then caused to turn and repel from or turn and align to bioactive borders. Conversely, physical cues dominate neurite path-finding as pattern feature slope increases, i.e. aspect ratio of sloping photopolymerized features increases, causing neurites to readily cross bioactive borders. The photopolymerization method developed in this work to generate micro and nanopatterned materials serves as an additional surface engineering tool that enables investigation of cell-material interactions including directed de novo neurite growth. The results of this interdisciplinary effort contribute substantially to polymer neural regeneration technology and will lead to development of advanced biomaterials that improve neural prosthetic tissue integration and performance by spatially directing nerve growth.

Identification of Primary Transcriptional Regulation of Cell Cycle-Regulated Genes upon DNA Damage

PubMed Central

Zhou, Tong; Chou, Jeff; Mullen, Thomas E.; Elkon, Rani; Zhou, Yingchun; Simpson, Dennis A.; Bushel, Pierre R.; Paules, Richard S.; Lobenhofer, Edward K.; Hurban, Patrick; Kaufmann, William K.

2007-01-01

The changes in global gene expression in response to DNA damage may derive from either direct induction or repression by transcriptional regulation or indirectly by synchronization of cells to specific cell cycle phases, such as G1 or G2. We developed a model that successfully estimated the expression levels of >400 cell cycle-regulated genes in normal human fibroblasts based on the proportions of cells in each phase of the cell cycle. By isolating effects on the gene expression associated with the cell cycle phase redistribution after genotoxin treatment, the direct transcriptional target genes were distinguished from genes for which expression changed secondary to cell synchronization. Application of this model to ionizing radiation (IR)-treated normal human fibroblasts identified 150 of 406 cycle-regulated genes as putative direct transcriptional targets of IR-induced DNA damage. Changes in expression of these genes after IR treatment derived from both direct transcriptional regulation and cell cycle synchronization. PMID:17404513

Enhancement of global flood damage assessments using building material based vulnerability curves

NASA Astrophysics Data System (ADS)

Englhardt, Johanna; de Ruiter, Marleen; de Moel, Hans; Aerts, Jeroen

2017-04-01

This study discusses the development of an enhanced approach for flood damage and risk assessments using vulnerability curves that are based on building material information. The approach draws upon common practices in earthquake vulnerability assessments, and is an alternative for land-use or building occupancy approach in flood risk assessment models. The approach is of particular importance for studies where there is a large variation in building material, such as large scale studies or studies in developing countries. A case study of Ethiopia is used to demonstrate the impact of the different methodological approaches on direct damage assessments due to flooding. Generally, flood damage assessments use damage curves for different land-use or occupancy types (i.e. urban or residential and commercial classes). However, these categories do not necessarily relate directly to vulnerability of damage by flood waters. For this, the construction type and building material may be more important, as is used in earthquake risk assessments. For this study, we use building material classification data of the PAGER1 project to define new building material based vulnerability classes for flood damage. This approach will be compared to the widely applied land-use based vulnerability curves such as used by De Moel et al. (2011). The case of Ethiopia demonstrates and compares the feasibility of this novel flood vulnerability method on a country level which holds the potential to be scaled up to a global level. The study shows that flood vulnerability based on building material also allows for better differentiation between flood damage in urban and rural settings, opening doors to better link to poverty studies when such exposure data is available. Furthermore, this new approach paves the road to the enhancement of multi-risk assessments as the method enables the comparison of vulnerability across different natural hazard types that also use material-based vulnerability curves. Finally, this approach allows for more accuracy in estimating losses as a result of direct damages. 1 http://earthquake.usgs.gov/data/pager/

Nervous system (image)

MedlinePlus

Peripheral Neuropathy is not a distinct disease, but the manifestation of many conditions that damage the peripheral nerves ( ... abnormal. Damaged motor nerves impair movement or function. Peripheral neuropathy may be caused by direct or indirect injury, ...

New Modeling Approaches to Study DNA Damage by the Direct and Indirect Effects of Ionizing Radiation

NASA Technical Reports Server (NTRS)

Plante, Ianik; Cucinotta, Francis A.

2012-01-01

DNA is damaged both by the direct and indirect effects of radiation. In the direct effect, the DNA itself is ionized, whereas the indirect effect involves the radiolysis of the water molecules surrounding the DNA and the subsequent reaction of the DNA with radical products. While this problem has been studied for many years, many unknowns still exist. To study this problem, we have developed the computer code RITRACKS [1], which simulates the radiation track structure for heavy ions and electrons, calculating all energy deposition events and the coordinates of all species produced by the water radiolysis. In this work, we plan to simulate DNA damage by using the crystal structure of a nucleosome and calculations performed by RITRACKS. The energy deposition events are used to calculate the dose deposited in nanovolumes [2] and therefore can be used to simulate the direct effect of the radiation. Using the positions of the radiolytic species with a radiation chemistry code [3] it will be possible to simulate DNA damage by indirect effect. The simulation results can be compared with results from previous calculations such as the frequencies of simple and complex strand breaks [4] and with newer experimental data using surrogate markers of DNA double ]strand breaks such as . ]H2AX foci [5].

The estimation of electrical cable fire-induced damage limits

NASA Astrophysics Data System (ADS)

Nowlen, S. P.; Jacobus, M. J.

Sandia National Laboratories has, for several years, been engaged in the performance of both fire safety and electrical equipment qualification research under independent programs sponsored by the US Nuclear Regulatory Commission. Recent comparisons between electrical cable thermal damageability data gathered independently in these two efforts indicate that a direct correlation exists between certain of the recent cable thermal vulnerability information gathered under equipment qualification conditions and thermal damageability in a fire environment. This direct correlation allows for a significant expansion of the data base on estimated cable thermal vulnerability limits in a fire environment because of the wide range of cable types and products that have been evaluated as a part of the equipment qualification research. This paper provides a discussion of the basis for the derived correlation, and presents estimated cable thermal damage limits for a wide range of generic cable types and specific cable products. The supposition that a direct correlation exists is supported through direct comparisons of the test results for certain specific cable products. The proposed supplemental cable fire vulnerability data gained from examination of the equipment qualification results is presented. These results should be of particular interest to those engaged in the evaluation of fire risk for industrial facilities, including nuclear power plants.

Prestraining and Its Influence on Subsequent Fatigue Life

NASA Technical Reports Server (NTRS)

Halford, Gary R.; Mcgaw, Michael A.; Kalluri, Sreeramesh

1995-01-01

An experimental program was conducted to study the damaging effects of tensile and compressive prestrains on the fatigue life of nickel-base, Inconel 718 superalloy at room temperature. To establish baseline fatigue behavior, virgin specimens with a solid uniform gage section were fatigued to failure under fully-reversed strain-control. Additional specimens were prestrained to 2 percent, 5 percent, and 10 percent (engineering strains) in the tensile direction and to 2 percent (engineering strain) in the compressive direction under stroke-control, and were subsequently fatigued to failure under fully-reversed strain-control. Experimental results are compared with estimates of remaining fatigue lives (after prestraining) using three life prediction approaches: (1) the Linear Damage Rule; (2) the Linear Strain and Life Fraction Rule; and (3) the nonlinear Damage Curve Approach. The Smith-Watson-Topper parameter was used to estimate fatigue lives in the presence of mean stresses. Among the cumulative damage rules investigated, best remaining fatigue life predictions were obtained with the nonlinear Damage Curve Approach.

Free radical development in phacoemulsification cataract surgery.

PubMed

Takahashi, Hiroshi

2005-02-01

Phacoemulsification and aspiration (PEA) has become the most popular cataract surgery, due to the establishment of safe surgical techniques and development of associated instruments. However, corneal endothelial damage still represents a serious complication, as excessive damage can lead to irreversible bullous keratopathy. In addition to causes such as mechanical or heat injuries, free radical formation due to ultrasound has been posited as another cause of corneal endothelium damage in PEA. Ultrasound in aqueous solution induces cavitation, directly causing water molecule disintegration and resulting in the formation of hydroxylradicals, the most potent of the reactive oxygen species. Considering the oxidative insult to endothelial cells caused by free radicals, their presence in the anterior chamber may represent one of the most harmful factors during these procedures. Indeed, some researchers have recently started to evaluate PEA from the perspective of oxidative stress. Conversely, the major ingredient in ophthalmic viscosurgical devices (OVDs), which are indispensable for maintaining the anterior chamber in PEA surgery, is sodium hyaluronate, a known free radical scavenger. OVDs can thus be expected to provide some anti-free radical effect during PEA procedures. In addition, since commercially available OVDs display different properties regarding retention in the anterior chamber during PEA, the anti-free radical effect of OVDs is likely to depend on behavior during irrigation and aspiration. The present study followed standard PEA procedures in an eye model and measured hydroxylradicals in the anterior chamber using electron spin resonance. The kinetics of free radical intensity and effects of several OVDs during clinical PEA were also demonstrated. These studies may be of significance in re-evaluating OVDs as a chemical protectant for corneal endothelium, since the OVD has thus far only been regarded as a physical barrier. In addition, many reports about corneal endothelium damage during PEA have been published, but objective evaluation of various damaging factors has been difficult. The present assay of free radicals in a simulation of clinical PEA offers the first method to quantitatively assess stress on the corneal endothelium.

Restructuring, Restoring and Rebuilding

ERIC Educational Resources Information Center

Hamilton, Kendra

2006-01-01

The 27 institutions damaged by hurricanes Katrina or Rita--there were 14 in Mississippi, 12 in Louisiana and one in Alabama--estimate their combined physical damages at $1.4 billion. But rather than providing aid, the Louisiana Legislature was forced to call for $77 million in cuts in November, leading to a wrenching gut-check on many campuses.…

Low-severity fire increases tree defense against bark beetle attacks

Treesearch

Sharon Hood; Anna Sala; Emily K. Heyerdahl; Marion Boutin

2015-01-01

Induced defense is a common plant strategy in response to herbivory. Although abiotic damage, such as physical wounding, pruning, and heating, can induce plant defense, the effect of such damage by large-scale abiotic disturbances on induced defenses has not been explored and could have important consequences for plant survival facing future biotic...

A Case Study of the Cognitive and Behavioral Deficits of Temporal Lobe Damage in Herpes Simplex Encephalitis.

ERIC Educational Resources Information Center

Greer, Margaret K.; And Others

1989-01-01

This case study illustrates the highly significant language difficulties, marked memory deficits, and propensity for physical aggression following temporal lobe damage brought about by herpes encephalitis, and presents the usefulness of a new diagnostic measure in delineating such a variable cognitive pattern. (Author)

48 CFR 1845.7209-3 - Loss, damage, or destruction of Government property while in contractor's possession or control.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... (b) When physical inventories, consumption analyses, or other actions disclose consumption of... required to reach a valid and supportable conclusion as to the contractor's liability for the loss, damage... assure proper credit. If analysis of contract provisions and circumstances establishes that the loss...

Multiple Damage Progression Paths in Model-Based Prognostics

NASA Technical Reports Server (NTRS)

Daigle, Matthew; Goebel, Kai Frank

2011-01-01

Model-based prognostics approaches employ domain knowledge about a system, its components, and how they fail through the use of physics-based models. Component wear is driven by several different degradation phenomena, each resulting in their own damage progression path, overlapping to contribute to the overall degradation of the component. We develop a model-based prognostics methodology using particle filters, in which the problem of characterizing multiple damage progression paths is cast as a joint state-parameter estimation problem. The estimate is represented as a probability distribution, allowing the prediction of end of life and remaining useful life within a probabilistic framework that supports uncertainty management. We also develop a novel variance control mechanism that maintains an uncertainty bound around the hidden parameters to limit the amount of estimation uncertainty and, consequently, reduce prediction uncertainty. We construct a detailed physics-based model of a centrifugal pump, to which we apply our model-based prognostics algorithms. We illustrate the operation of the prognostic solution with a number of simulation-based experiments and demonstrate the performance of the chosen approach when multiple damage mechanisms are active

Improving Metallic Thermal Protection System Hypervelocity Impact Resistance Through Design of Experiments Approach

NASA Technical Reports Server (NTRS)

Poteet, Carl C.; Blosser, Max L.

2001-01-01

A design of experiments approach has been implemented using computational hypervelocity impact simulations to determine the most effective place to add mass to an existing metallic Thermal Protection System (TPS) to improve hypervelocity impact protection. Simulations were performed using axisymmetric models in CTH, a shock-physics code developed by Sandia National Laboratories, and validated by comparison with existing test data. The axisymmetric models were then used in a statistical sensitivity analysis to determine the influence of five design parameters on degree of hypervelocity particle dispersion. Several damage metrics were identified and evaluated. Damage metrics related to the extent of substructure damage were seen to produce misleading results, however damage metrics related to the degree of dispersion of the hypervelocity particle produced results that corresponded to physical intuition. Based on analysis of variance results it was concluded that the most effective way to increase hypervelocity impact resistance is to increase the thickness of the outer foil layer. Increasing the spacing between the outer surface and the substructure is also very effective at increasing dispersion.

Pacific Northwest Laboratory annual report for 1988 to the DOE Office of Energy Research: Part 4, Physical sciences

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

Touburen, L.H.

1989-03-01

This document contains brief descriptions of various research programs in the physical science. Topics include Chernobyl Information Management, Supercritical Fluids, Laser Spectroscopy, DNA Adducts, Dosimetry, Biophysics, and Genetic Damage. (TEM)

78 FR 6251 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-30

... airplanes. This proposed AD was prompted by reports of cracks and heat damage on pivot joint components... proposing this AD to detect and correct heat damage and cracks in the pivot pin, truck beam lugs, and inner... joint components have been found with cracks or heat damage. There have been 11 such findings on Model...

75 FR 47201 - Airworthiness Directives; Eurocopter France Model EC 130 B4 Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-05

... each electrical harness for chaffing, tears, holes, or other damage at the location of each attachment... electrical harness for any chaffing, tear, hole, or other damage at the location of each attachment screw and... harness for chaffing, a tear, a hole, or other damage at the location of each attachment screw as depicted...

77 FR 52265 - Airworthiness Directives; Eurocopter Deutschland GmbH Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-29

... total area of corrosion or thread damage, or both, covers less than 25 percent of the length of the... paragraph (d)(3) of this AD. (B) If the total area of corrosion or thread damage, or both, covers 25 percent... to require inspections for corrosion or thread damage to each tail rotor balance weight (weight) and...

77 FR 68061 - Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-15

...) pylon for a loose or missing fastener, a crack, damage, or corrosion and adding an internal doubler to... actions are intended to detect a loose or missing fastener, a crack, damage, or corrosion on the T/R pylon..., a crack, damage, or corrosion, and repairing or replacing the T/R pylon if any of these conditions...

The Iceman's last weeks

NASA Astrophysics Data System (ADS)

Spindler, Konrad

1994-06-01

The author presents the archaeological, botanical and anatomical of medical evidence relating to the events of the last few days of the Iceman's life. The unfinished arrows and the half-completed bow indicate that he had lost his weapons and was in the process of re-arming himself. The quiver and the two primed arrows show clear signs of damage that has been proved to originate from before entombment in the ice of Hauslabjoch. An intravital series of fractured ribs and atrophic changes to the humerus on the same side of the body are also indicative of a violent conflict. The presence of threshing and winnowing fragments proves that, shortly before his death, the Iceman spent some time in a human settlement in which the grain crop was threshed. The theory is therefore proposed that shortly before his death the Iceman suffered some personal catastrophe involving damage to his possessions and physical injury. He fled in the direction of the inner Ötz Valley, a region of high alpine pastures he may have been familiar with from summer transhumance. Just beyond the ridge of the main Alpine chain he was caught by a sudden fall in temperature and snowfall, which he did not survive.

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

Nguyen, Thao; Luscher, D. J.; Wilkerson, J. W.

We developed a framework for dislocation-based viscoplasticity and dynamic ductile failure to model high strain rate deformation and damage in single crystals. The rate-dependence of the crystal plasticity formulation is based on the physics of relativistic dislocation kinetics suited for extremely high strain rates. The damage evolution is based on the dynamics of void growth, which are governed by both micro-inertia as well as dislocation kinetics and dislocation substructure evolution. Furthermore, an averaging scheme is proposed in order to approximate the evolution of the dislocation substructure in both the macroscale as well as its spatial distribution at the microscale. Inmore » addition, a concept of a single equivalent dislocation density that effectively captures the collective influence of dislocation density on all active slip systems is proposed here. Together, these concepts and approximations enable the use of semi-analytic solutions for void growth dynamics developed in [J. Wilkerson and K. Ramesh. A dynamic void growth model governed by dislocation kinetics. J. Mech. Phys. Solids, 70:262–280, 2014.], which greatly reduce the computational overhead that would otherwise be required. The resulting homogenized framework has been implemented into a commercially available finite element package, and a validation study against a suite of direct numerical simulations was carried out.« less

Dynamic Sumoylation of a Conserved Transcription Corepressor Prevents Persistent Inclusion Formation during Hyperosmotic Stress

PubMed Central

Oeser, Michelle L.; Amen, Triana; Nadel, Cory M.; Bradley, Amanda I.; Reed, Benjamin J.; Jones, Ramon D.; Gopalan, Janani; Kaganovich, Daniel; Gardner, Richard G.

2016-01-01

Cells are often exposed to physical or chemical stresses that can damage the structures of essential biomolecules. Stress-induced cellular damage can become deleterious if not managed appropriately. Rapid and adaptive responses to stresses are therefore crucial for cell survival. In eukaryotic cells, different stresses trigger post-translational modification of proteins with the small ubiquitin-like modifier SUMO. However, the specific regulatory roles of sumoylation in each stress response are not well understood. Here, we examined the sumoylation events that occur in budding yeast after exposure to hyperosmotic stress. We discovered by proteomic and biochemical analyses that hyperosmotic stress incurs the rapid and transient sumoylation of Cyc8 and Tup1, which together form a conserved transcription corepressor complex that regulates hundreds of genes. Gene expression and cell biological analyses revealed that sumoylation of each protein directs distinct outcomes. In particular, we discovered that Cyc8 sumoylation prevents the persistence of hyperosmotic stress-induced Cyc8-Tup1 inclusions, which involves a glutamine-rich prion domain in Cyc8. We propose that sumoylation protects against persistent inclusion formation during hyperosmotic stress, allowing optimal transcriptional function of the Cyc8-Tup1 complex. PMID:26800527

A dislocation-based crystal plasticity framework for dynamic ductile failure of single crystals

NASA Astrophysics Data System (ADS)

Nguyen, Thao; Luscher, D. J.; Wilkerson, J. W.

2017-11-01

A framework for dislocation-based viscoplasticity and dynamic ductile failure has been developed to model high strain rate deformation and damage in single crystals. The rate-dependence of the crystal plasticity formulation is based on the physics of relativistic dislocation kinetics suited for extremely high strain rates. The damage evolution is based on the dynamics of void growth, which are governed by both micro-inertia as well as dislocation kinetics and dislocation substructure evolution. An averaging scheme is proposed in order to approximate the evolution of the dislocation substructure in both the macroscale as well as its spatial distribution at the microscale. Additionally, a concept of a single equivalent dislocation density that effectively captures the collective influence of dislocation density on all active slip systems is proposed here. Together, these concepts and approximations enable the use of semi-analytic solutions for void growth dynamics developed in (Wilkerson and Ramesh, 2014), which greatly reduce the computational overhead that would otherwise be required. The resulting homogenized framework has been implemented into a commercially available finite element package, and a validation study against a suite of direct numerical simulations was carried out.

A Cause and A Solution for the Underprediction of Extreme Wave Events in the Northeast Pacific

NASA Astrophysics Data System (ADS)

Ellenson, A. N.; Ozkan-Haller, H. T.; Thomson, J.; Brown, A. C.; Haller, M. C.

2016-12-01

Along the coastlines of Washington and Oregon, at least one 10 m wave height event occurs every year, and the strongest storms produce wave heights of 14-15 m. Extremely high wave heights can cause severe damage to coastal infrastructure and pose hazards to stakeholders along the coast. A system which can accurately predict such sea states is important for quantifying risk and aiding in preparation for extreme wave events. This study explores how to optimize forecast model performance for extreme wave events by utilizing different physics packages or wind input in four model configurations. The different wind input products consist of a reanalyzed Global Forecasting System (GFS) wind input and a Climate Forecast System Reanalysis (CFSR) from the National Center of Environmental Prediction (NCEP). The physics packages are the Tolman-Chalikov (1996) ST2 physics package and the Ardhuin et al (2009) ST4 physics package associated with version 4.18 of WaveWatch III. A hindcast was previously performed to assess the wave character along the Pacific Northwest Coastline for wave energy applications. Inspection of hindcast model results showed that the operational model, which consisted of ST2 physics and GFS wind, underpredicted events where wave height exceeded six meters.The under-prediction is most severe for cases with the combined conditions of a distant cyclone and a strong coastal jet. Three such cases were re-analyzed with the four model configurations. Model output is compared with observations at NDBC buoy 46050, offshore of Newport, OR. The model configuration consisting of ST4 physics package and CFSR wind input performs best as compared with the original model, reducing significant wave height underprediction from 1.25 m to approximately 0.67 m and mean wave direction error from 30 degrees to 17 degrees for wave heights greater than 6 m. Spectral analysis shows that the ST4-CFSR model configuration best resolves southerly wave energy, and all model configurations tend to overestimate northerly wave energy. This directional distinction is important when attempting to identify which atmospheric feature has induced the extreme wave energy.

Flood Control, State Road and Ebner Coulees, La Crosse, Wisconsin, General Design Memorandum. Phase I. Plan Formulation and Hydrology and Draft Environmental Impact Statement.

DTIC Science & Technology

1982-04-01

development of the floodplain by use of appropriate floodplain management techniques to reduce flood losses . h. In the event of future development or...the total annual flood damages in the study area. These losses include physical damages to land, buildings, equipment, and stocks of merchandise as...well as the loss of wages and business profits and the costs of emergency protection. Average annual commercial damages are estimated at $253,000. The

A life prediction model for laminated composite structural components

NASA Technical Reports Server (NTRS)

Allen, David H.

1990-01-01

A life prediction methodology for laminated continuous fiber composites subjected to fatigue loading conditions was developed. A summary is presented of research completed. A phenomenological damage evolution law was formulated for matrix cracking which is independent of stacking sequence. Mechanistic and physical support was developed for the phenomenological evolution law proposed above. The damage evolution law proposed above was implemented to a finite element computer program. And preliminary predictions were obtained for a structural component undergoing fatigue loading induced damage.

Study of the surface activation of ETFE by low energy (keV) Si and N bombardment

NASA Astrophysics Data System (ADS)

Parada, M. A.; de Almeida, A.; Muntele, C.; Muntele, I.; Delalez, N.; Ila, D.

2005-12-01

The ethylenetetrafluoroethylene (ETFE) is a polymer formed by alternating ethylene and tetrafluoroethylene segments. It can be applied in the field of medical physics as intra venous catheters and as radiation dosimeters. The increasing application of polymeric materials in technological and scientific fields has motivated the use of surface treatments to modify the physical and chemical properties of polymer surfaces. When a material is exposed to ionizing radiation, it suffers damage leading to surface activation depending on the type, energy and intensity of the applied radiation. In order to determine the radiation damage and the surface activation mechanism ETFE films were bombarded with keV Si and N at various fluences. The bombarded film was also analyzed with optical absorption photospectrometry (OAP), Raman and Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy showing quantitatively the chemical nature at the damage caused by the Si and N bombardment.

The condition of neighborhood parks following Hurricane Katrina: development of a Post-Hurricane Assessment instrument.

PubMed

Bedimo-Rung, Ariane L; Thomson, Jessica L; Mowen, Andrew J; Gustat, Jeanette; Tompkins, Bradley J; Strikmiller, Patricia K; Sothern, Melinda S

2008-01-01

Parks provide environments for physical activity, yet little is known about how natural disasters affect them or how these disasters alter physical activity. Our objectives were to (1) describe the development of an instrument to assess park conditions following a hurricane and (2) document the conditions of New Orleans' parks 3 and 6 months after Hurricane Katrina. A Post-Hurricane Assessment (PHA) instrument was developed and implemented in 54 parks 3 and 6 months post-hurricane. Summary scores of the Park Damage Index and the Neighborhood Damage Index showed improvement between 3 and 6 months of data collection. Parks and neighborhoods most affected by the hurricane were located in the most- and least-affluent areas of the city. The PHA proved to be a promising tool for assessing park conditions in a timely manner following a natural disaster and allowed for the creation of summary damage scores to correlate to community changes.

Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

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

Laha, Dipranjan; Pramanik, Arindam; Laskar, Aparna

Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Sphericalmore » shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain.« less

Sirt1 physically interacts with Tip60 and negatively regulates Tip60-mediated acetylation of H2AX

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

Yamagata, Kazutsune, E-mail: kyamagat@ncc.go.jp; Kitabayashi, Issay

2009-12-25

Sirt1 appear to be NAD(+)-dependent deacetylase that deacetylates histones and several non-histone proteins. In this study, we identified Sirt1 as a physical interaction partner of Tip60, which is a mammalian MYST-type histone acetyl-transferase that specifically acetylates histones H2A and H4. Although Tip60 also acetylates DNA damage-specific histone H2A variant H2AX in response to DNA damage, which is a process required for appropriate DNA damage response, overexpression of Sirt1 represses Tip60-mediated acetylation of H2AX. Furthermore, Sirt1 depletion by RNAi causes excessive acetylation of H2AX, and enhances accumulation of {gamma}-ray irradiation-induced MDC1, BRCA1, and Rad51 foci in nuclei. These findings suggest thatmore » Sirt1 functions as negative regulator of Tip60-mediated acetylation of H2AX. Moreover, Sirt1 deacetylates an acetylated Tip60 in response to DNA damage and stimulates proteasome-dependent Tip60 degradation in vivo, suggesting that Sirt1 negatively regulates the protein level of Tip60 in vivo. Sirt1 may thus repress excessive activation of the DNA damage response and Rad51-homologous recombination repair by suppressing the function of Tip60.« less

Effects of used lubricating oil on two mangroves Aegiceras corniculatum and Avicennia marina.

PubMed

Ye, Yong; Tam, N F Y

2007-01-01

An outdoor experiment was set up to investigate the effects of used lubricating oil (5 L/m2) on Aegiceras corniculatum Blanco. and Avicennia marina (Forsk) Vierh., two salt-excreting mangroves. A. marina was more sensitive to used lubricating oil than A. corniculatum and canopy-oiling resulted in more direct physical damage and stronger lethal effects than base-oiling. When treated with canopy-oiling, half of A. corniculatum plants survived for the whole treatment time (90 d); but, for A. marina, high mortality (83%) resulted from canopy-oiling within 3 weeks and no plants survived for 80 d. Base-oiling had no lethal effects onA. corniculatum plants even at the termination of this experiment, but 83% of A. marina plants died 80 d after treatment. Forty days after canopy-oiling, 93% of A. corniculatum leaves fell and no live leaves remained on A. marina plants. By the end of the experiment, base-oiling treatment resulted in about 45% of A. corniculatum leaves falling, while all A. marina leaves and buds were burned to die. Lubricating oil resulted in physiological damage to A. corniculatum leaves, including decreases in chlorophyll and carotenoid contents, nitrate reductase, peroxidase and superoxide dismutase activities, and increases in malonaldehyde contents. For both species, oil pollution significantly reduced leaf, root, and total biomass, but did not significantly affect stem biomass. Oil pollution resulted in damage to the xylem vessels of fine roots but not to those of mediate roots.

Metabolic syndrome induced by anticancer treatment in childhood cancer survivors.

PubMed

Chueh, Hee Won; Yoo, Jae Ho

2017-06-01

The number of childhood cancer survivors is increasing as survival rates improve. However, complications after treatment have not received much attention, particularly metabolic syndrome. Metabolic syndrome comprises central obesity, dyslipidemia, hypertension, and insulin resistance, and cancer survivors have higher risks of cardiovascular events compared with the general population. The mechanism by which cancer treatment induces metabolic syndrome is unclear. However, its pathophysiology can be categorized based on the cancer treatment type administered. Brain surgery or radiotherapy may induce metabolic syndrome by damaging the hypothalamic-pituitary axis, which may induce pituitary hormone deficiencies. Local therapy administered to particular endocrine organs directly damages the organs and causes hormone deficiencies, which induce obesity and dyslipidemia leading to metabolic syndrome. Chemotherapeutic agents interfere with cell generation and growth, damage the vascular endothelial cells, and increase the cardiovascular risk. Moreover, chemotherapeutic agents induce oxidative stress, which also induces metabolic syndrome. Physical inactivity caused by cancer treatment or the cancer itself, dietary restrictions, and the frequent use of antibiotics may also be risk factors for metabolic syndrome. Since childhood cancer survivors with metabolic syndrome have higher risks of cardiovascular events at an earlier age, early interventions should be considered. The optimal timing of interventions and drug use has not been established, but lifestyle modifications and exercise interventions that begin during cancer treatment might be beneficial and tailored education and interventions that account for individual patients' circumstances are needed. This review evaluates the recent literature that describes metabolic syndrome in cancer survivors, with a focus on its pathophysiology.

A Study on the Priority Selection of Sediment-related Desaster Evacuation Using Debris Flow Combination Degree of Risk

NASA Astrophysics Data System (ADS)

Woo, C.; Kang, M.; Seo, J.; Kim, D.; Lee, C.

2017-12-01

As the mountainous urbanization has increased the concern about landslides in the living area, it is essential to develop the technology to minimize the damage through quick identification and sharing of the disaster occurrence information. In this study, to establish an effective system of alert evacuation that has influence on the residents, we used the debris flow combination degree of risk to predict the risk of the disaster and the level of damage and to select evacuation priorities. Based on the GIS information, the physical strength and social vulnerability were determined by following the debris flow combination of the risk formula. The results classify the physical strength hazard rating of the debris flow combination of the through the normalization process. Debris flow the estimated residential population included in the damage range of the damage prediction map is based on the area and the unit size data. Prediction of occupant formula was calculated by applying different weighting to the resident population and users, and the result was classified into 5 classes as the debris flow physical strength. The debris flow occurrence physical strength and social and psychological vulnerability were classified into the classifications to be reflected in the debris flow integrated risk map using the matrix technique. In addition, to supplement the risk of incorporation of debris flow, we added weight to disaster vulnerable facilities that require a lot of time and manpower to evacuate. The basic model of welfare facilities was supplemented by using basic data, population density, employment density and GDP. First, evacuate areas with high integrated degree of risk level, and evacuate with consideration of physical class differences if classification difficult because of the same or similar grade among the management areas. When the physical hazard class difference is similar, the population difference of the area including the welfare facility is considered first, and the priority is decided in order of age distribution, population density by period, and class difference of residential facility. The results of this study are expected be used as basic data for establishing a safety net for landslide by evacuation systems for disasters. Keyword: Landslide, Debris flow, Early warning system, evacuation

Identification of minute damage in composite bridge structures equipped with fiber optic sensors using the location of neutral axis and finite element analysis

NASA Astrophysics Data System (ADS)

Li, Xi; Glisic, Branko

2016-04-01

By definition, the neutral axis of a loaded composite beam structure is the curve along which the section experiences zero bending strain. When no axial loading is present, the location of the neutral axis passes through the centroid of stiffness of the beam cross-section. In the presence of damage, the centroid of stiffness, as well as the neutral axis, shift from the healthy position. The concept of neutral axis can be widely applied to all beam-like structures. According to literature, a change in location of the neutral axis can be associated with damage in the corresponding cross-section. In this paper, the movement of neutral axis near locations of minute damage in a composite bridge structure was studied using finite element analysis and experimental results. The finite element model was developed based on a physical scale model of a composite simply-supported structure with controlled minute damage in the reinforced concrete deck. The structure was equipped with long-gauge fiber optic strain and temperature sensors at a healthy reference location as well as two locations of damage. A total of 12 strain sensors were installed during construction and used to monitor the structure during various loading events. This paper aims to explain previous experimental results which showed that the observed positions of neutral axis near damage locations were higher than the predicted healthy locations in some loading events. Analysis has shown that finite element analysis has potential to simulate and explain the physical behavior of the test structure.

Mechanisms of sulfur mustard analog 2-chloroethyl ethyl sulfide-induced DNA damage in skin epidermal cells and fibroblasts.

PubMed

Inturi, Swetha; Tewari-Singh, Neera; Gu, Mallikarjuna; Shrotriya, Sangeeta; Gomez, Joe; Agarwal, Chapla; White, Carl W; Agarwal, Rajesh

2011-12-15

Employing mouse skin epidermal JB6 cells and dermal fibroblasts, here we examined the mechanisms of DNA damage by 2-chloroethyl ethyl sulfide (CEES), a monofunctional analog of sulfur mustard (SM). CEES exposure caused H2A.X and p53 phosphorylation as well as p53 accumulation in both cell types, starting at 1h, that was sustained for 24h, indicating a DNA-damaging effect of CEES, which was also confirmed and quantified by alkaline comet assay. CEES exposure also induced oxidative stress and oxidative DNA damage in both cell types, measured by an increase in mitochondrial and cellular reactive oxygen species and 8-hydroxydeoxyguanosine levels, respectively. In the studies distinguishing between oxidative and direct DNA damage, 1h pretreatment with glutathione (GSH) or the antioxidant Trolox showed a decrease in CEES-induced oxidative stress and oxidative DNA damage. However, only GSH pretreatment decreased CEES-induced total DNA damage measured by comet assay, H2A.X and p53 phosphorylation, and total p53 levels. This was possibly due to the formation of GSH-CEES conjugates detected by LC-MS analysis. Together, our results show that CEES causes both direct and oxidative DNA damage, suggesting that to rescue SM-caused skin injuries, pleiotropic agents (or cocktails) are needed that could target multiple pathways of mustard skin toxicities. Copyright © 2011 Elsevier Inc. All rights reserved.

Aeroallergens Induce Reactive Oxygen Species Production and DNA Damage and Dampen Antioxidant Responses in Bronchial Epithelial Cells.

PubMed

Chan, Tze Khee; Tan, W S Daniel; Peh, Hong Yong; Wong, W S Fred

2017-07-01

Exposure to environmental allergens is a major risk factor for asthma development. Allergens possess proteolytic activity that is capable of disrupting the airway epithelium. Although there is increasing evidence pointing to asthma as an epithelial disease, the underlying mechanism that drives asthma has not been fully elucidated. In this study, we investigated the direct DNA damage potential of aeroallergens on human bronchial epithelial cells and elucidated the mechanisms mediating the damage. Human bronchial epithelial cells, BEAS-2B, directly exposed to house dust mites (HDM) resulted in enhanced DNA damage, as measured by the CometChip and the staining of DNA double-strand break marker, γH2AX. HDM stimulated cellular reactive oxygen species production, increased mitochondrial oxidative stress, and promoted nitrosative stress. Notably, expression of nuclear factor erythroid 2-related factor 2-dependent antioxidant genes was reduced immediately after HDM exposure, suggesting that HDM altered antioxidant responses. HDM exposure also reduced cell proliferation and induced cell death. Importantly, HDM-induced DNA damage can be prevented by the antioxidants glutathione and catalase, suggesting that HDM-induced reactive oxygen and nitrogen species can be neutralized by antioxidants. Mechanistic studies revealed that HDM-induced cellular injury is NADPH oxidase (NOX)-dependent, and apocynin, a NOX inhibitor, protected cells from double-strand breaks induced by HDM. Our results show that direct exposure of bronchial epithelial cells to HDM leads to the production of reactive oxygen and nitrogen species that damage DNA and induce cytotoxicity. Antioxidants and NOX inhibitors can prevent HDM-induced DNA damage, revealing a novel role for antioxidants and NOX inhibitors in mitigating allergic airway disease. Copyright © 2017 by The American Association of Immunologists, Inc.

Multiple roles of the cell cycle inhibitor p21(CDKN1A) in the DNA damage response.

PubMed

Cazzalini, Ornella; Scovassi, A Ivana; Savio, Monica; Stivala, Lucia A; Prosperi, Ennio

2010-01-01

Among cell cycle regulatory proteins that are activated following DNA damage, the cyclin-dependent kinase inhibitor p21(CDKN1A) plays essential roles in the DNA damage response, by inducing cell cycle arrest, direct inhibition of DNA replication, as well as by regulating fundamental processes, like apoptosis and transcription. These functions are performed through the ability of p21 to interact with a number of proteins involved in these processes. Despite an initial controversy, during the last years several lines of evidence have also indicated that p21 may be directly involved in DNA repair. In particular, the participation of p21 in nucleotide excision repair (NER), base excision repair (BER), and DNA translesion synthesis (TLS), has been suggested to occur thanks to its interaction with proliferating cell nuclear antigen (PCNA), a crucial protein involved in several aspects of DNA metabolism, and cell-cycle regulation. In this review, the multiple roles of p21 in the DNA damage response, including regulation of cell cycle, apoptosis and gene transcription, are discussed together with the most recent findings supporting the direct participation of p21 protein in DNA repair processes. In particular, spatio-temporal dynamics of p21 recruitment to sites of DNA damage will be considered together with several lines of evidence indicating a regulatory role for p21. In addition, the relevance of post-translational regulation in the fate (e.g. degradation) of p21 protein after cell exposure to DNA damaging agents will be analyzed. Both sets of evidence will be discussed in terms of the overall DNA damage response. 2010 Elsevier B.V. All rights reserved.

Economic costs of extratropical storms under climate change: An application of FUND

NASA Astrophysics Data System (ADS)

Narita, D.; Tol, R.; Anthoff, D.

2009-12-01

Extratropical cyclones have attracted some attention in climate policy circles as a possible significant damage factor of climate change. This study conducts an assessment of economic impacts of increased storm activities under climate change with the integrated assessment model FUND 3.5. FUND is a model that calculates damages of climate change for 16 regions by making use of exogenous scenarios of socioeconomic variables (for details of our estimation approach, see our working paper whose URL is indicated below). Our estimation shows that in the base case, the direct economic damage of enhanced storms due to climate change amounts to $2.8 billion globally (approximately 38% of the total economic loss of storms at present) at the year 2100, while the ratio to the world GDP is 0.0009%. The regional results (Figure 1) indicate that the economic effect of extratropical storms with climate change would have relatively minor importance for the US (USA): The enhanced extratropical storm damage (less than 0.001% of GDP for the base case) is one order of magnitude lower than the tropical cyclone damage (roughly 0.01% GDP) calculated by the same version of FUND. In the regions without strong tropical cyclone influence, such as Western Europe (WEU) and Australia and New Zealand (ANZ), the extratropical storms might have some more significance as a possible damage factor of climate change. Especially for the latter, the direct economic damage could amount to more than 0.006% of GDP. Still, the impact is small relative to the income growth expected in these regions. Figure 1. Increased direct economic loss at the year 2100 for selected regions (results are shown for the three different baselines: the years 1986-2005, 1976-2005, and 1996-2005). US - USA; Canada - CAN; Western Europe - WEU; Australia and New Zealand - ANZ.

Genotoxic and oxidative effects induced on A549 cells by extract of PM10 collected in an electric steel plant.

PubMed

Cavallo, Delia; Ursini, Cinzia L; Maiello, Raffaele; Apostoli, Pietro; Catalani, Simona; Ciervo, Aureliano; Iavicoli, Sergio

2008-01-01

The present study was aimed at assessing the carcinogenic risk of occupational exposure to PM10 in electric steel plants. PM10 was collected on cellulose filter respectively outside (site 1) and inside (site 2) the furnace area, was measured, extracted and its metal content was analysed by ICP-MS. Cells were exposed for 30 min, 2 and 4 hours to extract of filter from each site diluted at 0.004, 0.008 and 0.02%. The direct/oxidative DNA damage caused by PM10 was evaluated on A549 cells by Fpg-modified comet assay, analysing Tail moment (TM) and comet percentage. Air samples contained 1.08 mg/m3 of PM10 in site 1 and 5.54 mg/m3in site 2 and different amounts of metals with higher levels of Zn, Al, Ni, Pb, Cd, Cr, Ba in site 2 and of Fe, Mn, Sb in site 1. In cells exposed for 2h to PM10 from both sites, an oxidative DNA damage was found concentrations of 0.008% and 0.02%. For site 2, a direct DNA damage at 0.02% was also found. After 4h a direct/oxidative DNA damage was detected at 0.02% for site 2 and an oxidative DNA damage for site 1. The results indicate a moderate DNA damage induction by used diluitions of PM10 extracts with higher extent for more polluted site 2. These findings show the suitability of this experimental model to evaluate early DNA damage induced by complex mixtures containing metals on target organ, suggesting its use to study biological effects of occupational exposure to such substances.

Vascular injuries in knee dislocations: the role of physical examination in determining the need for arteriography.

PubMed

Stannard, James P; Sheils, Todd M; Lopez-Ben, Robert R; McGwin, Gerald; Robinson, James T; Volgas, David A

2004-05-01

Popliteal artery injury is frequently associated with knee dislocation following blunt trauma, an injury that is being seen with increasing frequency. The primary purpose of the present study was to evaluate the use of physical examination to determine the need for arteriography in a large series of patients with knee dislocation. The secondary purpose was to evaluate the correlation between physical examination findings and clinically important vascular injury in the subgroup of patients who underwent arteriography. One hundred and thirty consecutive patients (138 knees) who had sustained an acute multiligamentous knee injury were evaluated at our level-1 trauma center between August 1996 and May 2002 and were included in a prospective outcome study. Four patients (four knees) were lost to follow-up, leaving 126 patients (134 knees) available for inclusion in the study. The results of the physical examination of the vascular status of the extremities were used to determine the need for arteriography. The mean duration of follow-up was nineteen months (range, eight to forty-eight months). Physical examination findings, magnetic resonance imaging findings, and surgical findings were combined to determine the extent of ligamentous damage. Nine patients had flow-limiting popliteal artery damage, for an overall prevalence of 7%. Ten patients had abnormal findings on physical examination, with one patient having a false-positive result and nine having a true-positive result. The knee dislocations in the nine patients with popliteal artery damage were classified, according to the Wascher modification of the Schenck system, as KD-III (one knee), KD-IV (seven knees), and KD-V (one knee). Selective arteriography based on serial physical examinations is a safe and prudent policy following knee dislocation. There is a strong correlation between the results of physical examination and the need for arteriography. Increased vigilance may be justified in the case of a patient with a KD-IV dislocation, for whom serial examinations should continue for at least forty-eight hours.

Design, testing, and damage tolerance study of bonded stiffened composite wing cover panels

NASA Technical Reports Server (NTRS)

Madan, Ram C.; Sutton, Jason O.

1988-01-01

Results are presented from the application of damage tolerance criteria for composite panels to multistringer composite wing cover panels developed under NASA's Composite Transport Wing Technology Development contract. This conceptual wing design integrated aeroelastic stiffness constraints with an enhanced damage tolerance material system, in order to yield optimized producibility and structural performance. Damage tolerance was demonstrated in a test program using full-sized cover panel subcomponents; panel skins were impacted at midbay between stiffeners, directly over a stiffener, and over the stiffener flange edge. None of the impacts produced visible damage. NASTRAN analyses were performed to simulate NDI-detected invisible damage.

[Biochemical evaluation on rural workers exposed to pesticides].

PubMed

Simoniello, María Fernanda; Kleinsorge, Elisa C; Carballo, Marta A

2010-01-01

Pesticides are used in agriculture to protect crops but may represent a potential risk to farmers and the environment. The aim of this work was to evaluate horticultural workers exposed to pesticide, categorized by: direct exposure (n = 45), indirect exposure (n = 50) and controls (n = 50) using exposure and effect biomarkers: cholinesterase (ChE), acetylcholinesterase (AChE), catalase (CAT), lipid peroxidation (TBARS), Damage Index Comet Assay (IDEC) and Damage Index Repair Assay (IDER). Our results show: a) an AChE inhibition in directly and indirectly exposed population (p < 0.001), b) significant increase in the levels of TBARS in direct exposure (p < 0.001), c) the CAT reduction was significant (p < 0.01), d) a significant increase in IDEC and IDER in both exposed groups (p < 0.001). Our results evidence variations in oxidative balance and DNA damage in exposed workers. These findings represent a contribution to the sub-clinical evaluation of subjects exposed to agrochemicals in our country.

a Dosimetry Assessment for the Core Restraint of AN Advanced Gas Cooled Reactor

NASA Astrophysics Data System (ADS)

Thornton, D. A.; Allen, D. A.; Tyrrell, R. J.; Meese, T. C.; Huggon, A. P.; Whiley, G. S.; Mossop, J. R.

2009-08-01

This paper describes calculations of neutron damage rates within the core restraint structures of Advanced Gas Cooled Reactors (AGRs). Using advanced features of the Monte Carlo radiation transport code MCBEND, and neutron source data from core follow calculations performed with the reactor physics code PANTHER, a detailed model of the reactor cores of two of British Energy's AGR power plants has been developed for this purpose. Because there are no relevant neutron fluence measurements directly supporting this assessment, results of benchmark comparisons and successful validation of MCBEND for Magnox reactors have been used to estimate systematic and random uncertainties on the predictions. In particular, it has been necessary to address the known under-prediction of lower energy fast neutron responses associated with the penetration of large thicknesses of graphite.

Long-distance signalling in plant defence.

PubMed

Heil, Martin; Ton, Jurriaan

2008-06-01

Plants use inducible defence mechanisms to fend off harmful organisms. Resistance that is induced in response to local attack is often expressed systemically, that is, in organs that are not yet damaged. In the search for translocated defence signals, biochemical studies follow the physical movement of putative signals, and grafting experiments use mutants that are impaired in the production or perception of these signals. Long-distance signals can directly activate defence or can prime for the stronger and faster induction of defence. Historically, research has focused on the vascular transport of signalling metabolites, but volatiles can play a crucial role as well. We compare the advantages and constraints of vascular and airborne signals for the plant, and discuss how they can act in synergy to achieve optimised resistance in distal plant parts.

Northern Ireland and 'The Troubles', outlining an innovative approach to nursing/midwifery student teaching and module evaluation.

PubMed

McMullan, Johanna; Clarke, Susan A; O'Hagan, Marie Therese; O'Connor, Tony; Power, John J

2016-02-01

This discussion paper outlines an approach to developing and evaluating an educative programme primarily delivered by lay `citizen trainers' in educating student nurses, and student midwives to the impact of and experience of extended and extensive civil unrest within their communities (`the Troubles' ). This is drawn from experience within the Northern Ireland `Troubles' and all of the citizen trainers were directly affected physically/psychologically. The programme was intended to both educate but primarily to help facilitate student nurses and student midwives to better understanding to experience and context and to more effective care delivery to those affected by/damaged by `the Troubles'. Evaluation of the teaching and learning by the students was significantly positive. Copyright © 2015 Elsevier Ltd. All rights reserved.

Multi-Dimensional Damage Detection for Surfaces and Structures

NASA Technical Reports Server (NTRS)

Williams, Martha; Lewis, Mark; Roberson, Luke; Medelius, Pedro; Gibson, Tracy; Parks, Steen; Snyder, Sarah

2013-01-01

Current designs for inflatable or semi-rigidized structures for habitats and space applications use a multiple-layer construction, alternating thin layers with thicker, stronger layers, which produces a layered composite structure that is much better at resisting damage. Even though such composite structures or layered systems are robust, they can still be susceptible to penetration damage. The ability to detect damage to surfaces of inflatable or semi-rigid habitat structures is of great interest to NASA. Damage caused by impacts of foreign objects such as micrometeorites can rupture the shell of these structures, causing loss of critical hardware and/or the life of the crew. While not all impacts will have a catastrophic result, it will be very important to identify and locate areas of the exterior shell that have been damaged by impacts so that repairs (or other provisions) can be made to reduce the probability of shell wall rupture. This disclosure describes a system that will provide real-time data regarding the health of the inflatable shell or rigidized structures, and information related to the location and depth of impact damage. The innovation described here is a method of determining the size, location, and direction of damage in a multilayered structure. In the multi-dimensional damage detection system, layers of two-dimensional thin film detection layers are used to form a layered composite, with non-detection layers separating the detection layers. The non-detection layers may be either thicker or thinner than the detection layers. The thin-film damage detection layers are thin films of materials with a conductive grid or striped pattern. The conductive pattern may be applied by several methods, including printing, plating, sputtering, photolithography, and etching, and can include as many detection layers that are necessary for the structure construction or to afford the detection detail level required. The damage is detected using a detector or sensory system, which may include a time domain reflectometer, resistivity monitoring hardware, or other resistance-based systems. To begin, a layered composite consisting of thin-film damage detection layers separated by non-damage detection layers is fabricated. The damage detection layers are attached to a detector that provides details regarding the physical health of each detection layer individually. If damage occurs to any of the detection layers, a change in the electrical properties of the detection layers damaged occurs, and a response is generated. Real-time analysis of these responses will provide details regarding the depth, location, and size estimation of the damage. Multiple damages can be detected, and the extent (depth) of the damage can be used to generate prognostic information related to the expected lifetime of the layered composite system. The detection system can be fabricated very easily using off-the-shelf equipment, and the detection algorithms can be written and updated (as needed) to provide the level of detail needed based on the system being monitored. Connecting to the thin film detection layers is very easy as well. The truly unique feature of the system is its flexibility; the system can be designed to gather as much (or as little) information as the end user feels necessary. Individual detection layers can be turned on or off as necessary, and algorithms can be used to optimize performance. The system can be used to generate both diagnostic and prognostic information related to the health of layer composite structures, which will be essential if such systems are utilized for space exploration. The technology is also applicable to other in-situ health monitoring systems for structure integrity.

On the classification of normalized natural frequencies for damage detection in cantilever beam

NASA Astrophysics Data System (ADS)

Dahak, Mustapha; Touat, Noureddine; Benseddiq, Noureddine

2017-08-01

The presence of a damage on a beam causes changes in the physical properties, which introduce flexibility, and reduce the natural frequencies of the beam. Based on this, a new method is proposed to locate the damage zone in a cantilever beam. In this paper, the cantilever beam is discretized into a number of zones, where each zone has a specific classification of the first four normalized natural frequencies. The damaged zone is distinguished by only the classification of the normalized frequencies of the structure. In the case when the damage is symmetric to the vibration node, we use the unchanged natural frequency as a second information to obtain a more accurate location. The effectiveness of the proposed method is shown by a numerical simulation with ANSYS software and experimental investigation of a cantilever beam with different damage.

Laser-induced damage of coatings on Yb:YAG crystals at cryogenic condition

NASA Astrophysics Data System (ADS)

Wang, He; Zhang, Weili; Chen, Shunli; Zhu, Meiping; He, Hongbo; Fan, Zhengxiu

2011-12-01

As large amounts of heat need to be dissipated during laser operation, some diode pumped solid state lasers (DPSSL), especially Yb:YAG laser, operate at cryogenic condition. This work investigated the laser induced damage of coatings (high-reflective and anti-reflective coatings) on Yb:YAG crystals at cryogenic temperature and room temperature. The results show that the damage threshold of coatings at cryogenic temperature is lower than the one at room temperature. Field-emission scanning electron microscopy (FESEM), optical profiler, step profiler and Atomic force microscope (AFM) were used to obtain the damage morphology, size and depth. Taking alteration of physical parameters, microstructure of coatings and the environmental pollution into consideration, we analyzed the key factor of lowering the coating damage threshold at cryogenic conditions. The results are important to understand the mechanisms leading to damage at cryogenic condition.

A Micro-Mechanism-Based Continuum Corrosion Fatigue Damage Model for Steels

NASA Astrophysics Data System (ADS)

Sun, Bin; Li, Zhaoxia

2018-05-01

A micro-mechanism-based corrosion fatigue damage model is developed for studying the high-cycle corrosion fatigue of steel from multi-scale viewpoint. The developed physical corrosion fatigue damage model establishes micro-macro relationships between macroscopic continuum damage evolution and collective evolution behavior of microscopic pits and cracks, which can be used to describe the multi-scale corrosion fatigue process of steel. As a case study, the model is used to predict continuum damage evolution and number density of the corrosion pit and short crack of steel component in 5% NaCl water under constant stress amplitude at 20 kHz, and the numerical results are compared with experimental results. It shows that the model is effective and can be used to evaluate the continuum macroscopic corrosion fatigue damage and study microscopic corrosion fatigue mechanisms of steel.

A Micro-Mechanism-Based Continuum Corrosion Fatigue Damage Model for Steels

NASA Astrophysics Data System (ADS)

Sun, Bin; Li, Zhaoxia

2018-04-01

A micro-mechanism-based corrosion fatigue damage model is developed for studying the high-cycle corrosion fatigue of steel from multi-scale viewpoint. The developed physical corrosion fatigue damage model establishes micro-macro relationships between macroscopic continuum damage evolution and collective evolution behavior of microscopic pits and cracks, which can be used to describe the multi-scale corrosion fatigue process of steel. As a case study, the model is used to predict continuum damage evolution and number density of the corrosion pit and short crack of steel component in 5% NaCl water under constant stress amplitude at 20 kHz, and the numerical results are compared with experimental results. It shows that the model is effective and can be used to evaluate the continuum macroscopic corrosion fatigue damage and study microscopic corrosion fatigue mechanisms of steel.

Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

NASA Astrophysics Data System (ADS)

Xi, Xiao-Wen; Chai, Chang-Chun; Liu, Yang; Yang, Yin-Tang; Fan, Qing-Yang; Shi, Chun-Lei

2016-08-01

An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900) and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

Navy Enhanced Sierra Mechanics (NESM): Toolbox for predicting Navy shock and damage

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

Moyer, Thomas; Stergiou, Jonathan; Reese, Garth

Here, the US Navy is developing a new suite of computational mechanics tools (Navy Enhanced Sierra Mechanics) for the prediction of ship response, damage, and shock environments transmitted to vital systems during threat weapon encounters. NESM includes fully coupled Euler-Lagrange solvers tailored to ship shock/damage predictions. NESM is optimized to support high-performance computing architectures, providing the physics-based ship response/threat weapon damage predictions needed to support the design and assessment of highly survivable ships. NESM is being employed to support current Navy ship design and acquisition programs while being further developed for future Navy fleet needs.

Helium vs. Proton Induced Displacement Damage in Electronic Materials

NASA Technical Reports Server (NTRS)

Ringo, Sawnese; Barghouty, A. F.

2010-01-01

In this project, the specific effects of displacement damage due to the passage of protons and helium nuclei on some typical electronic materials will be evaluated and contrasted. As the electronic material absorbs the energetic proton and helium momentum, degradation of performance occurs, eventually leading to overall failure. Helium nuclei traveling at the same speed as protons are expected to impart more to the material displacement damage; due to the larger mass, and thus momentum, of helium nuclei compared to protons. Damage due to displacement of atoms in their crystalline structure can change the physical properties and hence performance of the electronic materials.

Navy Enhanced Sierra Mechanics (NESM): Toolbox for predicting Navy shock and damage

DOE PAGES

Moyer, Thomas; Stergiou, Jonathan; Reese, Garth; ...

2016-05-25

Here, the US Navy is developing a new suite of computational mechanics tools (Navy Enhanced Sierra Mechanics) for the prediction of ship response, damage, and shock environments transmitted to vital systems during threat weapon encounters. NESM includes fully coupled Euler-Lagrange solvers tailored to ship shock/damage predictions. NESM is optimized to support high-performance computing architectures, providing the physics-based ship response/threat weapon damage predictions needed to support the design and assessment of highly survivable ships. NESM is being employed to support current Navy ship design and acquisition programs while being further developed for future Navy fleet needs.

The effect of dimethyl sulfoxide on the induction of DNA strand breaks in plasmid DNA and colony formation of PC Cl3 mammalian cells by alpha-, beta-, and Auger electron emitters (223)Ra, (188)Re, and (99m)Tc.

PubMed

Runge, Roswitha; Oehme, Liane; Kotzerke, Jörg; Freudenberg, Robert

2016-12-01

DNA damage occurs as a consequence of both direct and indirect effects of ionizing radiation. The severity of DNA damage depends on the physical characteristics of the radiation quality, e.g., the linear energy transfer (LET). There are still contrary findings regarding direct or indirect interactions of high-LET emitters with DNA. Our aim is to determine DNA damage and the effect on cellular survival induced by (223)Ra compared to (188)Re and (99m)Tc modulated by the radical scavenger dimethyl sulfoxide (DMSO). Radioactive solutions of (223)Ra, (188)Re, or (99m)Tc were added to either plasmid DNA or to PC Cl3 cells in the absence or presence of DMSO. Following irradiation, single strand breaks (SSB) and double strand breaks (DSB) in plasmid DNA were analyzed by gel electrophoresis. To determine the radiosensitivity of the rat thyroid cell line (PC Cl3), survival curves were performed using the colony formation assay. Exposure to 120 Gy of (223)Ra, (188)Re, or (99m)Tc leads to maximal yields of SSB (80 %) in plasmid DNA. Irradiation with 540 Gy (223)Ra and 500 Gy (188)Re or (99m)Tc induced 40, 28, and 64 % linear plasmid conformations, respectively. DMSO prevented the SSB and DSB in a similar way for all radionuclides. However, with the α-emitter (223)Ra, a low level of DSB could not be prevented by DMSO. Irradiation of PC Cl3 cells with (223)Ra, (188)Re, and (99m)Tc pre-incubated with DMSO revealed enhanced survival fractions (SF) in comparison to treatment without DMSO. Protection factors (PF) were calculated using the fitted survival curves. These factors are 1.23 ± 0.04, 1.20 ± 0.19, and 1.34 ± 0.05 for (223)Ra, (188)Re, and (99m)Tc, respectively. For (223)Ra, as well as for (188)Re and (99m)Tc, dose-dependent radiation effects were found applicable for plasmid DNA and PC Cl3 cells. The radioprotection by DMSO was in the same range for high- and low-LET emitter. Overall, the results indicate the contribution of mainly indirect radiation effects for each of the radionuclides regarding DNA damage and cell survival. In summary, our findings may contribute to fundamental knowledge about the α-particle induced DNA damage.

Stiffness degradation-based damage model for RC members and structures using fiber-beam elements

NASA Astrophysics Data System (ADS)

Guo, Zongming; Zhang, Yaoting; Lu, Jiezhi; Fan, Jian

2016-12-01

To meet the demand for an accurate and highly efficient damage model with a distinct physical meaning for performance-based earthquake engineering applications, a stiffness degradation-based damage model for reinforced concrete (RC) members and structures was developed using fiber beam-column elements. In this model, damage indices for concrete and steel fibers were defined by the degradation of the initial reloading modulus and the low-cycle fatigue law. Then, section, member, story and structure damage was evaluated by the degradation of the sectional bending stiffness, rod-end bending stiffness, story lateral stiffness and structure lateral stiffness, respectively. The damage model was realized in Matlab by reading in the outputs of OpenSees. The application of the damage model to RC columns and a RC frame indicates that the damage model is capable of accurately predicting the magnitude, position, and evolutionary process of damage, and estimating story damage more precisely than inter-story drift. Additionally, the damage model establishes a close connection between damage indices at various levels without introducing weighting coefficients or force-displacement relationships. The development of the model has perfected the damage assessment function of OpenSees, laying a solid foundation for damage estimation at various levels of a large-scale structure subjected to seismic loading.

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

McNally, J.J.

The effects on the properties of Ta/sub 2/O/sub 5/, Al/sub 2/O/sub 3/, SiO/sub 2/ and HfO/sub 2/ single- and multi-layer optical coatings deposited using ion-assisted deposition (IAD) were investigated. IAD is a novel deposition technique which utilizes a separate ion source to direct a beam of ions at the growing film. A Kaufman ion source was used to provide a monoenergetic, neutralized beam of oxygen ions independent of the material evaporation process. The optical and physical properties, as well as laser induced damage threshold (LIDT) values, were studied for coatings bombarded with 200, 300, 500 and 1000 eV oxygen ionsmore » at values of current density from 0 to 200 microAmp/sq cm. IAD was successfully applied to deposit coatings at low temperature on heavy metal fluoride (HMF) glass substrates. The coatings deposited using IAD were hard and dense. The IAD coatings improved the durability and abrasion resistance of the HMF glass substrates. The results of this investigation show that IAD can be used to improve the optical and physical properties of optical coatings.« less

The Effects of Physical Exercise on Fatty Liver Disease

PubMed Central

van der Windt, Dirk J.; Sud, Vikas; Zhang, Hongji; Tsung, Allan; Huang, Hai

2018-01-01

The increasing prevalence of obesity has made nonalcoholic fatty liver disease (NAFLD) the most common chronic liver disease. As a consequence, NAFLD and especially its inflammatory form nonalcoholic steatohepatitis (NASH) are the fastest increasing etiology of end-stage liver disease and hepatocellular carcinoma. Physical inactivity is related to the severity of fatty liver disease irrespective of body weight, supporting the hypothesis that increasing physical activity through exercise can improve fatty liver disease. This review summarizes the evidence for the effects of physical exercise on NAFLD and NASH. Several clinical trials have shown that both aerobic and resistance exercise reduce the hepatic fat content. From clinical and basic scientific studies, it is evident that exercise affects fatty liver disease through various pathways. Improved peripheral insulin resistance reduces the excess delivery of free fatty acids and glucose for free fatty acid synthesis to the liver. In the liver, exercise increases fatty acid oxidation, decreases fatty acid synthesis, and prevents mitochondrial and hepatocellular damage through a reduction of the release of damage-associated molecular patterns. In conclusion, physical exercise is a proven therapeutic strategy to improve fatty liver disease. PMID:29212576

Nanocrystal ghosting: Extensive radiation damage in MgO induced by low-energy electrons

NASA Astrophysics Data System (ADS)

Frankenfield, Zackery; Kane, Kenneth; Sawyer, William H.

2017-03-01

We report direct evidence of extensive radiation damage in MgO nanocrystals due to intense bombardment (2 × 10 electrons/nm sec) by electrons with beam energies between 60 keV and 120 keV. Based upon a minimum intensity necessary to produce the observed damage, we present an explanation based on the Knotek-Feibelman process.

A CAF-1–PCNA-Mediated Chromatin Assembly Pathway Triggered by Sensing DNA Damage

PubMed Central

Moggs, Jonathan G.; Grandi, Paola; Quivy, Jean-Pierre; Jónsson, Zophonías O.; Hübscher, Ulrich; Becker, Peter B.; Almouzni, Geneviève

2000-01-01

Sensing DNA damage is crucial for the maintenance of genomic integrity and cell cycle progression. The participation of chromatin in these events is becoming of increasing interest. We show that the presence of single-strand breaks and gaps, formed either directly or during DNA damage processing, can trigger the propagation of nucleosomal arrays. This nucleosome assembly pathway involves the histone chaperone chromatin assembly factor 1 (CAF-1). The largest subunit (p150) of this factor interacts directly with proliferating cell nuclear antigen (PCNA), and critical regions for this interaction on both proteins have been mapped. To isolate proteins specifically recruited during DNA repair, damaged DNA linked to magnetic beads was used. The binding of both PCNA and CAF-1 to this damaged DNA was dependent on the number of DNA lesions and required ATP. Chromatin assembly linked to the repair of single-strand breaks was disrupted by depletion of PCNA from a cell-free system. This defect was rescued by complementation with recombinant PCNA, arguing for role of PCNA in mediating chromatin assembly linked to DNA repair. We discuss the importance of the PCNA–CAF-1 interaction in the context of DNA damage processing and checkpoint control. PMID:10648606

Blast induced mild traumatic brain injury/concussion: A physical analysis

NASA Astrophysics Data System (ADS)

Kucherov, Yan; Hubler, Graham K.; DePalma, Ralph G.

2012-11-01

Currently, a consensus exists that low intensity non-impact blast wave exposure leads to mild traumatic brain injury (mTBI). Considerable interest in this "invisible injury" has developed in the past few years but a disconnect remains between the biomedical outcomes and possible physical mechanisms causing mTBI. Here, we show that a shock wave travelling through the brain excites a phonon continuum that decays into specific acoustic waves with intensity exceeding brain tissue strength. Damage may occur within the period of the phonon wave, measured in tens to hundreds of nanometers, which makes the damage difficult to detect using conventional modalities.

Anisotropy of Single-Crystal Silicon in Nanometric Cutting.

PubMed

Wang, Zhiguo; Chen, Jiaxuan; Wang, Guilian; Bai, Qingshun; Liang, Yingchun

2017-12-01

The anisotropy exhibited by single-crystal silicon in nanometric cutting is very significant. In order to profoundly understand the effect of crystal anisotropy on cutting behaviors, a large-scale molecular dynamics model was conducted to simulate the nanometric cutting of single-crystal silicon in the (100)[0-10], (100)[0-1-1], (110)[-110], (110)[00-1], (111)[-101], and (111)[-12-1] crystal directions in this study. The simulation results show the variations of different degrees in chip, subsurface damage, cutting force, and friction coefficient with changes in crystal plane and crystal direction. Shear deformation is the formation mechanism of subsurface damage, and the direction and complexity it forms are the primary causes that result in the anisotropy of subsurface damage. Structurally, chips could be classified into completely amorphous ones and incompletely amorphous ones containing a few crystallites. The formation mechanism of the former is high-pressure phase transformation, while the latter is obtained under the combined action of high-pressure phase transformation and cleavage. Based on an analysis of the material removal mode, it can be found that compared with the other crystal direction on the same crystal plane, the (100)[0-10], (110)[-110], and (111)[-101] directions are more suitable for ductile cutting.

Conophthorin from almond host plant and fungal spores and its ecological relation to navel orangeworm: a natural products chemist's perspective

USDA-ARS?s Scientific Manuscript database

The navel orangeworm (Amyelois transitella) is a major insect pest that brings about significant monetary damage to California tree nuts – almonds, pistachios, and walnuts. During their development, larvae of navel orangeworm feed upon the meat of these nuts causing physical damage and ultimately lo...

Bacterial stem blight of alfalfa: A disease that increases frost damage

USDA-ARS?s Scientific Manuscript database

Alfalfa producers count on the first harvest in late spring to deliver the highest tonnage and best quality of forage of the year. A late frost can significantly reduce both yield and quality. Losses are due not only to the physical damage from freezing of the alfalfa stem and leaves but also from d...

DNA oxidative damage and life expectancy in houseflies.

PubMed Central

Agarwal, S; Sohal, R S

1994-01-01

The objective of this study was to explore the relationship between oxidative molecular damage and the aging process by determining whether such damage is associated with the rate of aging, using the adult housefly as the experimental organism. Because the somatic tissues in the housefly consist of long-lived postmitotic cells, it provides an excellent model system for studying cumulative age-related cellular alterations. Rate of aging in the housefly was manipulated by varying the rate of metabolism (physical activity). The concentration of 8-hydroxydeoxyguanosine (80HdG) was used as an indicator of DNA oxidation. Exposure of live flies to x-rays and hyperoxia elevated the level of 8OHdG. The level of 8OHdG in mitochondrial as well as total DNA increased with the age of flies. Mitochondrial DNA was 3 times more susceptible to age-related oxidative damage than nuclear DNA. A decrease in the level of physical activity of the flies was found to prolong the life-span and corresponding reduce the level of 8OHdG in both mitochondrial and total DNA. Under all conditions examined, mitochondrial DNA exhibited a higher level of oxidative damage than total DNA. The 8OHdG levels were found to be inversely associated with the life expectancy of houseflies. The pattern of age-associated accrural of 8OHdG was virtually identical to that of protein carbonyl content. Altoghether, results of this study support the hypothesis that oxidative molecular damage is a causal factor in senescence. PMID:7991627

Electromagnetomechanical elastodynamic model for Lamb wave damage quantification in composites

NASA Astrophysics Data System (ADS)

Borkowski, Luke; Chattopadhyay, Aditi

2014-03-01

Physics-based wave propagation computational models play a key role in structural health monitoring (SHM) and the development of improved damage quantification methodologies. Guided waves (GWs), such as Lamb waves, provide the capability to monitor large plate-like aerospace structures with limited actuators and sensors and are sensitive to small scale damage; however due to the complex nature of GWs, accurate and efficient computation tools are necessary to investigate the mechanisms responsible for dispersion, coupling, and interaction with damage. In this paper, the local interaction simulation approach (LISA) coupled with the sharp interface model (SIM) solution methodology is used to solve the fully coupled electro-magneto-mechanical elastodynamic equations for the piezoelectric and piezomagnetic actuation and sensing of GWs in fiber reinforced composite material systems. The final framework provides the full three-dimensional displacement as well as electrical and magnetic potential fields for arbitrary plate and transducer geometries and excitation waveform and frequency. The model is validated experimentally and proven computationally efficient for a laminated composite plate. Studies are performed with surface bonded piezoelectric and embedded piezomagnetic sensors to gain insight into the physics of experimental techniques used for SHM. The symmetric collocation of piezoelectric actuators is modeled to demonstrate mode suppression in laminated composites for the purpose of damage detection. The effect of delamination and damage (i.e., matrix cracking) on the GW propagation is demonstrated and quantified. The developed model provides a valuable tool for the improvement of SHM techniques due to its proven accuracy and computational efficiency.

Religious Engagement in a Risky Family Model Predicting Health in Older Black and White Seventh-day Adventists

PubMed Central

Morton, Kelly R.; Lee, Jerry W.; Haviland, Mark G.; Fraser, Gary E.

2012-01-01

In a structural equation model, associations among latent variables – Child Poverty, Risky Family exposure, Religious Engagement, Negative Social Interactions, Negative Emotionality, and Perceived Physical Health – were evaluated in 6,753 Black and White adults aged 35–106 years (M = 60.5, SD = 13.0). All participants were members of the Seventh-day Adventist church surveyed in the Biopsychosocial Religion and Health Study (BRHS). Child Poverty was positively associated with both Risky Family exposure (conflict, neglect, abuse) and Religious Engagement (intrinsic religiosity, religious coping, religiousness). Risky Family was negatively associated with Religious Engagement and positively associated with both Negative Social Interactions (intrusive, failed to help, insensitive, rejecting) and Negative Emotionality (depression, negative affect, neuroticism). Religious Engagement was negatively associated with Negative Emotionality and Negative Social Interactions at a given level of risky family. Negative Social Interactions was positively associated with Negative Emotionality, which had a direct, negative effect on Perceived Physical Health. All constructs had indirect effects on Perceived Physical Health through Negative Emotionality. The effects of a risky family environment appear to be enduring, negatively affecting one’s adult religious life, emotionality, social interactions, and perceived health. Religious engagement, however, may counteract the damaging effects of early life stress. PMID:23560134

[Physiotherapy and ergotherapy are indispensable. Concrete prescription of remedies - without recourse].

PubMed

Engel, J-M

2012-07-01

Physical therapy and occupational therapy are essential for the treatment of inflammatory rheumatic diseases equal in rank to any drug therapy. They have enough evidence and are part of all current guidelines even if mostly not specified. In the German social security system the doctor prescribing physical therapy or occupational therapy has to act according to the different rules and forms as described in the current "Heilmittel Richtlinie" (Remedy directive) effective since July 2011. The multiple formal conditions and requirements of prescriptions are described in detail. Of special interest is that the global diagnosis of rheumatoid arthritis can no longer be used as the reason or justification for the individual prescription but detailed sub-diagnoses, regarding the essential ICF domains of structural damage, functional impairment, activity limitation and participation restriction as well as individual context factors are necessary. Of special interest is the fact that the prescribing doctor is no longer responsible for the formal correctness of prescriptions but the performing therapist, who will not be reimbursed if the prescription shows even minor formal errors. Another important improvement is the newly introduced long-term prescription of physical and occupational therapy. This facilitates the application of these therapies in the multimodal treatment regimen of rheumatic diseases.

Racial/ethnic identity and subjective physical and mental health of Latino Americans: an asset within?

PubMed

Ai, Amy L; Aisenberg, Eugene; Weiss, Saskia I; Salazar, Dulny

2014-03-01

Social Identity Theory indicates that ethnic identity could benefit minority members in a society because of its promotion of a sense of belonging, or of its buffering of the damage of discrimination. Despite growing investigation about Latinos' overall health, few studies have simultaneously examined the influence of multiple cultural strength factors, especially racial/ethnic identity, social support, and religious attendance, on these outcomes. Using the National Latino and Asian American Study, we examine the potential predictive value of these cultural strength factors on Latinos' Self-Rated Mental and Physical Health (SRMH and SRPH). Two separate two-step regression models revealed significant positive effects of racial/ethnic identity on both mental and physical health of Latinos, above and beyond the effect of known demographic and acculturation factors, such as discrimination. Religious attendance had a positive effect on SRMH but not on SRPH. The deteriorating roles of discrimination, in mental health only, and that of Length in the US in both outcomes, however, was primarily not altered by entry of these cultural strength factors. The independent direct effect of racial/ethnic identity among Latinos nationwide may suggest that this cultural strength is an internalized protective asset. Longitudinal data is needed to explore its underlying mechanism and long-term impact.

Influence of disintegrants in different substrate physical form on dimensional recovery of multi-component tablet.

PubMed

Sarkar, Srimanta; Ooi, Shing Ming; Liew, Celine Valeria; Tan, Bing Xun; Heng, Paul Wan Sia

2014-11-20

This study investigated the influence of different disintegrants, present in different substrate physical forms, on dimensional recovery of multi-component tablets prepared at different compression pressures. Formulations containing model drug, metformin, (10%, w/w), different disintegrants (10%, w/w), and lactose (80%, w/w) were compressed directly or after granulation using polyvinyl pyrrolidone (1%, w/w) as binder, into tablets (350 mg, 10mm diameter) at 150, 200, and 250 N/mm(2) compression pressures. Tablets were characterized for immediate dimensional recovery (IR) after ejection from the die, latent dimensional recovery (LR) over 24 h, tensile strength, and disintegration. The IR was predominantly contributed by crystalline components whereas LR was brought about by polymeric materials. With increased compression pressure, higher degree of plastic deformation of the polymeric disintegrants resulted in tablet with lower LR and higher tensile strength. Presence of polyvinyl pyrrolidone in the granules contributed considerably to plastic deformation, and the tablets produced had lower LR, higher tensile strength, and longer disintegration time. This study indicated that use of granules as the feed substrate physical form and a prudent selection of components may enable the coating of resultant tablets immediately after compression without the risk of coat damage due to LR. Copyright © 2014 Elsevier B.V. All rights reserved.

The surgical anatomy of the infrapatellar branch of the saphenous nerve in relation to incisions for anteromedial knee surgery.

PubMed

Kerver, A L A; Leliveld, M S; den Hartog, D; Verhofstad, M H J; Kleinrensink, G J

2013-12-04

Iatrogenic injury to the infrapatellar branch of the saphenous nerve is a common complication of surgical approaches to the anteromedial side of the knee. A detailed description of the relative anatomic course of the nerve is important to define clinical guidelines and minimize iatrogenic damage during anterior knee surgery. In twenty embalmed knees, the infrapatellar branch of the saphenous nerve was dissected. With use of a computer-assisted surgical anatomy mapping tool, safe and risk zones, as well as the location-dependent direction of the nerve, were calculated. The location of the infrapatellar branch of the saphenous nerve is highly variable, and no definite safe zone could be identified. The infrapatellar branch runs in neither a purely horizontal nor a vertical course. The course of the branch is location-dependent. Medially, it runs a nearly vertical course; medial to the patellar tendon, it has a -45° distal-lateral course; and on the patella and patellar tendon, it runs a close to horizontal-lateral course. Three low risk zones for iatrogenic nerve injury were identified: one is on the medial side of the knee, at the level of the tibial tuberosity, where a -45° oblique incision is least prone to damage the nerves, and two zones are located medial to the patellar apex (cranial and caudal), where close to horizontal incisions are least prone to damage the nerves. The infrapatellar branch of the saphenous nerve is at risk for iatrogenic damage in anteromedial knee surgery, especially when longitudinal incisions are made. There are three low risk zones for a safer anterior approach to the knee. The direction of the infrapatellar branch of the saphenous nerve is location-dependent. To minimize iatrogenic damage to the nerve, the direction of incisions should be parallel to the direction of the nerve when technically possible. These findings suggest that iatrogenic damage of the infrapatellar branch of the saphenous nerve can be minimized in anteromedial knee surgery when both the location and the location-dependent direction of the nerve are considered when making the skin incision.

Chromatin Relaxation-Mediated Induction of p19INK4d Increases the Ability of Cells to Repair Damaged DNA

PubMed Central

Carcagno, Abel L.; Marazita, Mariela C.; Sonzogni, Silvina V.; Ceruti, Julieta M.; Cánepa, Eduardo T.

2013-01-01

The maintenance of genomic integrity is of main importance to the survival and health of organisms which are continuously exposed to genotoxic stress. Cells respond to DNA damage by activating survival pathways consisting of cell cycle checkpoints and repair mechanisms. However, the signal that triggers the DNA damage response is not necessarily a direct detection of the primary DNA lesion. In fact, chromatin defects may serve as initiating signals to activate those mechanisms. If the modulation of chromatin structure could initiate a checkpoint response in a direct manner, this supposes the existence of specific chromatin sensors. p19INK4d, a member of the INK4 cell cycle inhibitors, plays a crucial role in regulating genomic stability and cell viability by enhancing DNA repair. Its expression is induced in cells injured by one of several genotoxic treatments like cis-platin, UV light or neocarzinostatin. Nevertheless, when exogenous DNA damaged molecules are introduced into the cell, this induction is not observed. Here, we show that p19INK4d is enhanced after chromatin relaxation even in the absence of DNA damage. This induction was shown to depend upon ATM/ATR, Chk1/Chk2 and E2F activity, as is the case of p19INK4d induction by endogenous DNA damage. Interestingly, p19INK4d improves DNA repair when the genotoxic damage is caused in a relaxed-chromatin context. These results suggest that changes in chromatin structure, and not DNA damage itself, is the actual trigger of p19INK4d induction. We propose that, in addition to its role as a cell cycle inhibitor, p19INK4d could participate in a signaling network directed to detecting and eventually responding to chromatin anomalies. PMID:23593412

77 FR 30350 - Louisiana Disaster #LA-00045

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

..., tornadoes and flooding. Incident Period: 03/20/2012 through 03/22/2012. Effective Date: 05/15/2012. Physical..., Calcasieu, Jefferson Davis, Vernon. Texas Newton. The Interest Rates are: Percent For Physical Damage... States which received an EIDL Declaration are Louisiana and Texas. (Catalog of Federal Domestic...

Is Childhood Obesity Related to TV Addiction?

ERIC Educational Resources Information Center

Groves, David

1988-01-01

Excessive television viewing is associated with obesity in children because it decreases time spent on physical activity, and promotes overeating of snacks and high calorie foods. Childhood obesity demands physicians' concern because of the physical and psychological damage which follows its victims into adulthood. (IAH)

[The role of the biological damaging factor in the explosive injury].

PubMed

Popov, V L; Kadochnikov, D S; Minaeva, P V

2015-01-01

This article describes the specific features of the action of the biological damaging factors on the human organism associated with the explosive injury. Both the direct action of the damaging agents contained in the biological weapons and their secondary effects in the form of systemic and local infectious complications of the inflicted wounds are considered. The criteria for the evaluation of the degree of harm to the health of the victims of explosion attributable to the action of the biological damaging factor are proposed.

Monte Carlo Treatment of Displacement Damage in Bandgap Engineered HgCdTe Detectors

NASA Technical Reports Server (NTRS)

Fodness, Bryan C.; Marshall, Paul W.; Reed, Robert A.; Jordan, Thomas M.; Pickel, James C.; Jun, Insoo; Xapsos, Michael A.; Burke, Edward A.

2003-01-01

The conclusion are: 1. Description of NIEL calculation for short, mid, and longwave HgCdTe material compositions. 2. Full recoil spectra details captured and analyzed Importance of variance in high Z materials. 3. Can be applied directly to calculate damage distributions in arrays. 4. Future work will provide comparisons of measured array damage with calculated NIEL and damage energy distributions. 5. Technique to assess the full recoil spectrum behavior is extendable to other materials.

Combining wet etching and real-time damage event imaging to reveal the most dangerous laser damage initiator in fused silica.

PubMed

Hu, Guohang; Zhao, Yuanan; Liu, Xiaofeng; Li, Dawei; Xiao, Qiling; Yi, Kui; Shao, Jianda

2013-08-01

A reliable method, combining a wet etch process and real-time damage event imaging during a raster scan laser damage test, has been developed to directly determine the most dangerous precursor inducing low-density laser damage at 355 nm in fused silica. It is revealed that ~16% of laser damage sites were initiated at the place of the scratches, ~49% initiated at the digs, and ~35% initiated at invisible defects. The morphologies of dangerous scratches and digs were compared with those of moderate ones. It is found that local sharp variation at the edge, twist, or inside of a subsurface defect is the most dangerous laser damage precursor.

Mechanisms of DNA Damage Response to Targeted Irradiation in Organotypic 3D Skin Cultures

PubMed Central

Acheva, Anna; Ghita, Mihaela; Patel, Gaurang; Prise, Kevin M.; Schettino, Giuseppe

2014-01-01

DNA damage (caused by direct cellular exposure and bystander signaling) and the complex pathways involved in its repair are critical events underpinning cellular and tissue response following radiation exposures. There are limited data addressing the dynamics of DNA damage induction and repair in the skin particularly in areas not directly exposed. Here we investigate the mechanisms regulating DNA damage, repair, intracellular signalling and their impact on premature differentiation and development of inflammatory-like response in the irradiated and surrounding areas of a 3D organotypic skin model. Following localized low-LET irradiation (225 kVp X-rays), low levels of 53BP1 foci were observed in the 3D model (3.8±0.28 foci/Gy/cell) with foci persisting and increasing in size up to 48 h post irradiation. In contrast, in cell monolayers 14.2±0.6 foci/Gy/cell and biphasic repair kinetics with repair completed before 24 h was observed. These differences are linked to differences in cellular status with variable level of p21 driving apoptotic signalling in 2D and accelerated differentiation in both the directly irradiated and bystander areas of the 3D model. The signalling pathways utilized by irradiated keratinocytes to induce DNA damage in non-exposed areas of the skin involved the NF-κB transcription factor and its downstream target COX-2. PMID:24505255

Extracting the distribution of laser damage precursors on fused silica surfaces for 351 nm, 3 ns laser pulses at high fluences (20-150 J/cm2).

PubMed

Laurence, Ted A; Bude, Jeff D; Ly, Sonny; Shen, Nan; Feit, Michael D

2012-05-07

Surface laser damage limits the lifetime of optics for systems guiding high fluence pulses, particularly damage in silica optics used for inertial confinement fusion-class lasers (nanosecond-scale high energy pulses at 355 nm/3.5 eV). The density of damage precursors at low fluence has been measured using large beams (1-3 cm); higher fluences cannot be measured easily since the high density of resulting damage initiation sites results in clustering. We developed automated experiments and analysis that allow us to damage test thousands of sites with small beams (10-30 µm), and automatically image the test sites to determine if laser damage occurred. We developed an analysis method that provides a rigorous connection between these small beam damage test results of damage probability versus laser pulse energy and the large beam damage results of damage precursor densities versus fluence. We find that for uncoated and coated fused silica samples, the distribution of precursors nearly flattens at very high fluences, up to 150 J/cm2, providing important constraints on the physical distribution and nature of these precursors.

15. VIEW DIRECTLY INTO CENTER FISH HOLD, STARBOARD SIDE. THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW DIRECTLY INTO CENTER FISH HOLD, STARBOARD SIDE. THE HORIZONTAL SCANTLINGS ON EACH BULKHEAD ARE 57" ABOVE THE BOTTOM OF THE HOLD. EXPERIENCE SHOWED THAT THE WEIGHT OF ICE PILED TO GREATER DEPTHS WOULD DAMAGE FISH ON THE BOTTOM OF THE HOLD. CONSEQUENTLY, MOST HOLDS ON FISHING BOATS HAVE A SHELF AT THIS HEIGHT TO PREVENT DAMAGING THE CATCH. - Auxiliary Fishing Schooner "Evelina M. Goulart", Essex Shipbuilding Museum, 66 Main Street, Essex, Essex County, MA

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

Xu, W.; Zhu, W. D.; Smith, S. A.

While structural damage detection based on flexural vibration shapes, such as mode shapes and steady-state response shapes under harmonic excitation, has been well developed, little attention is paid to that based on longitudinal vibration shapes that also contain damage information. This study originally formulates a slope vibration shape for damage detection in bars using longitudinal vibration shapes. To enhance noise robustness of the method, a slope vibration shape is transformed to a multiscale slope vibration shape in a multiscale domain using wavelet transform, which has explicit physical implication, high damage sensitivity, and noise robustness. These advantages are demonstrated in numericalmore » cases of damaged bars, and results show that multiscale slope vibration shapes can be used for identifying and locating damage in a noisy environment. A three-dimensional (3D) scanning laser vibrometer is used to measure the longitudinal steady-state response shape of an aluminum bar with damage due to reduced cross-sectional dimensions under harmonic excitation, and results show that the method can successfully identify and locate the damage. Slopes of longitudinal vibration shapes are shown to be suitable for damage detection in bars and have potential for applications in noisy environments.« less

Spatio-Temporal Features of Visual Exploration in Unilaterally Brain-Damaged Subjects with or without Neglect: Results from a Touchscreen Test

PubMed Central

Rabuffetti, Marco; Farina, Elisabetta; Alberoni, Margherita; Pellegatta, Daniele; Appollonio, Ildebrando; Affanni, Paola; Forni, Marco; Ferrarin, Maurizio

2012-01-01

Cognitive assessment in a clinical setting is generally made by pencil-and-paper tests, while computer-based tests enable the measurement and the extraction of additional performance indexes. Previous studies have demonstrated that in a research context exploration deficits occur also in patients without evidence of unilateral neglect at pencil-and-paper tests. The objective of this study is to apply a touchscreen-based cancellation test, feasible also in a clinical context, to large groups of control subjects and unilaterally brain-damaged patients, with and without unilateral spatial neglect (USN), in order to assess disturbances of the exploratory skills. A computerized cancellation test on a touchscreen interface was used for assessing the performance of 119 neurologically unimpaired control subjects and 193 patients with unilateral right or left hemispheric brain damage, either with or without USN. A set of performance indexes were defined including Latency, Proximity, Crossings and their spatial lateral gradients, and Preferred Search Direction. Classic outcome scores were computed as well. Results show statistically significant differences among groups (assumed p<0.05). Right-brain-damaged patients with USN were significantly slower (median latency per detected item was 1.18 s) and less efficient (about 13 search-path crossings) in the search than controls (median latency 0.64 s; about 3 crossings). Their preferred search direction (53.6% downward, 36.7% leftward) was different from the one in control patients (88.2% downward, 2.1% leftward). Right-brain-damaged patients without USN showed a significantly abnormal behavior (median latency 0.84 s, about 5 crossings, 83.3% downward and 9.1% leftward direction) situated half way between controls and right-brain-damaged patients with USN. Left-brain-damaged patients without USN were significantly slower and less efficient than controls (latency 1.19 s, about 7 crossings), preserving a normal preferred search direction (93.7% downward). Therefore, the proposed touchscreen-based assessment had evidenced disorders in spatial exploration also in patients without clinically diagnosed USN. PMID:22347489

Interactions between low energy electrons and DNA: a perspective from first-principles simulations

NASA Astrophysics Data System (ADS)

Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A.; Gu, Bin

2017-09-01

DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation—either photons or swift ions—and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

Interactions between low energy electrons and DNA: a perspective from first-principles simulations.

PubMed

Kohanoff, Jorge; McAllister, Maeve; Tribello, Gareth A; Gu, Bin

2017-09-27

DNA damage caused by irradiation has been studied for many decades. Such studies allow us to better assess the dangers posed by radiation, and to increase the efficiency of the radiotherapies that are used to combat cancer. A full description of the irradiation process involves multiple size and time scales. It starts with the interaction of radiation-either photons or swift ions-and the biological medium, which causes electronic excitation and ionisation. The two main products of ionising radiation are thus electrons and radicals. Both of these species can cause damage to biological molecules, in particular DNA. In the long run, this molecular level damage can prevent cells from replicating and can hence lead to cell death. For a long time it was assumed that the main actors in the damage process were the radicals. However, experiments in a seminal paper by the group of Leon Sanche in 2000 showed that low-energy electrons (LEE), such as those generated when ionising biological targets, can also cause bond breaks in biomolecules, and strand breaks in plasmid DNA in particular (Boudaiffa et al 2000 Science 287 1658-60). These results prompted a significant amount of experimental and theoretical work aimed at elucidating the role played by LEE in DNA damage. In this Topical Review we provide a general overview of the problem. We discuss experimental findings and theoretical results hand in hand with the aim of describing the physics and chemistry that occurs during the process of radiation damage, from the initial stages of electronic excitation, through the inelastic propagation of electrons in the medium, the interaction of electrons with DNA, and the chemical end-point effects on DNA. A very important aspect of this discussion is the consideration of a realistic, physiological environment. The role played by the aqueous solution and the amino acids from the histones in chromatin must be considered. Moreover, thermal fluctuations must be incorporated when studying these phenomena. Hence, a special place in this Topical Review is occupied by our recent first-principles molecular dynamics simulations that address the issue of how the environment favours or prevents LEEs from causing damage to DNA. We finish by summarising the conclusions achieved so far, and by suggesting a number of possible directions for further study.

Impact of shock wave pattern and cavitation bubble size on tissue damage during ureteroscopic electrohydraulic lithotripsy.

PubMed

Vorreuther, R; Corleis, R; Klotz, T; Bernards, P; Engelmann, U

1995-03-01

It is known that electrohydraulic lithotripsy (EHL) during ureteroscopy may cause ureteral damage. To evaluate this trauma potential, find its mechanism and make it possible to avoid it, our research employed photographic evaluation, tissue studies, shock wave measurements and disintegration tests. The setup included a 3.3 F probe attached to an experimental generator with adjustable voltages and capacities providing energies from 25 mJ. to 1300 mJ. per pulse. In general, we distinguish between two traumatic mechanisms: (1) After placing the probe directly on the mucosa the rapid initial plasma penetrates the tissue resulting in a small, nonthermal, punched-like defect, whose depth depends on the energy applied. This trauma has minor clinical implications and is avoided by maintaining a minimum safety distance of 1 mm.; (2) According to physics, each plasma is followed by a cavitation bubble. The maximum size of this bubble depends on the energy applied and ranges from 3 mm. (25 mJ) to > 15 mm. (1300 mJ). In proportion to the bubble size, the ureteral wall may be distended or disrupted, even when the probe is not in direct contact with the mucosa. Therefore, the goal should be to obtain a low energy pressure pulse with high disintegration efficacy. Our evaluation of the pressure waves revealed that the selection of a high voltage and a low capacity leads to short and steep "laser-like" pulses. These pulses have a significant higher impact on stone disintegration than the broader pulses of the same energy provided by currently available generators.

Estimating the economic impact of seismic activity in Kyrgyzstan

NASA Astrophysics Data System (ADS)

Pittore, Massimiliano; Sousa, Luis; Grant, Damian; Fleming, Kevin; Parolai, Stefano; Free, Matthew; Moldobekov, Bolot; Takeuchi, Ko

2017-04-01

Estimating the short and long-term economical impact of large-scale damaging events such as earthquakes, tsunamis or tropical storms is an important component of risk assessment, whose outcomes are routinely used to improve risk awareness, optimize investments in prevention and mitigation actions, as well as to customize insurance and reinsurance rates to specific geographical regions or single countries. Such estimations can be carried out by modeling the whole causal process, from hazard assessment to the estimation of loss for specific categories of assets. This approach allows a precise description of the various physical mechanisms contributing to direct seismic losses. However, it should reflect the underlying epistemic and random uncertainties in all involved components in a meaningful way. Within a project sponsored by the World Bank, a seismic risk study for the Kyrgyz Republic has been conducted, focusing on the assessment of social and economical impacts assessed in terms of direct losses of the residential and public building stocks. Probabilistic estimates based on stochastic event catalogs have been computed and integrated with the simulation of specific earthquake scenarios. Although very few relevant data are available in the region on the economic consequences of past damaging events, the proposed approach sets a benchmark for decision makers and policy holders to better understand the short and long term consequences of earthquakes in the region. The presented results confirm the high level of seismic risk of the Kyrgyz Republic territory, outlining the most affected regions; thus advocating for significant Disaster Risk Reduction (DRR) measures to be implemented by local decision- and policy-makers.

Environmental management of a highly impacted, urbanized tropical estuary: rehabilitation and restoration

NASA Astrophysics Data System (ADS)

Thorhaug, A.

1980-03-01

The principles of the dynamics and interrelationships within the dominant subtropical and tropical Caribbean seagrass community have been studied previously before, during, and after impact. From these and scores of observations of damage and recovery patterns in Thalassia ecosystems, a sense of management recovery strategy has emerged. Artificial restoring of Thalassia testudinum seeds into areas cut off from stock (fruit, seeds) appeared feasible on a large scale after the Turkey Point (Biscayne Bay, Miami, Florida) restoration and test sampling throughout North Biscayne Bay. Two large-scale seeding attempts were made; after 11 months they compared favorably with Turkey Point specimens with regard to growth parameters, despite the turbidity and other persistent pollution. Thus, the possible areas in which Thalassia seed restoration can be used has increased to include estuaries of multiple impact still in various stages of recovery after physical and sewage pollution. This technique should be especially useful to “developing” nations where important nearshore fisheries nurseries based on Thalassia ecosystems have been heavily damaged and now lie barren. Man's impact on the estuary where seed restoration was attempted includes the following activities: 50% of the bay bottom directly dredged or filled (leaving much unconsolidated sediment); 50 million gallons of domestic waste dumped directly into a low flushing part of the bay for 20 years; seven major causeways transecting the bay, restricting circulation and flushing; two artificial inlets made into navigational channels; freshwater sheet flow drastically changed due to channelization by flood-control canals; urban runoff from a million people entering the bay. Most of the impacts have now abated; however, their long-term effects remain.

Fabrication and characterization of UV-emitting nanoparticles as novel radiation sensitizers targeting hypoxic tumor cells

NASA Astrophysics Data System (ADS)

Squillante, Michael R.; Jüstel, Thomas; Anderson, R. Rox; Brecher, Charles; Chartier, Daniel; Christian, James F.; Cicchetti, Nicholas; Espinoza, Sara; McAdams, Daniel R.; Müller, Matthias; Tornifoglio, Brooke; Wang, Yimin; Purschke, Martin

2018-06-01

Radiation therapy is one of the primary therapeutic techniques for treating cancer, administered to nearly two-thirds of all cancer patients. Although largely effective in killing cancer cells, radiation therapy, like other forms of cancer treatment, has difficulty dealing with hypoxic regions within solid tumors. The incomplete killing of cancer cells can lead to recurrence and relapse. The research presented here is investigating the enhancement of the efficacy of radiation therapy by using scintillating nanoparticles that emit UV photons. UV photons, with wavelengths between 230 nm and 280 nm, are able to inactivate cells due to their direct interaction with DNA, causing a variety of forms of damage. UV-emitting nanoparticles will enhance the treatment in two ways: first by generating UV photons in the immediate vicinity of cancer cells, leading to direct and oxygen-independent DNA damage, and second by down-converting the applied higher energy X-rays into softer X-rays and particles that are more efficiently absorbed in the targeted tumor region. The end result will be nanoparticles with a higher efficacy in the treatment of hypoxic cells in the tumor, filling an important, unmet clinical need. Our preliminary experiments show an increase in cell death using scintillating LuPO4:Pr nanoparticles over that achieved by the primary radiation alone. This work describes the fabrication of the nanoparticles, their physical characterization, and the spectroscopic characterization of the UV emission. The work also presents in vitro results that demonstrate an enhanced efficacy of cell killing with x-rays and a low unspecific toxicity of the nanoparticles.

Securing Paternity by Mutilating Female Genitalia in Spiders.

PubMed

Mouginot, Pierick; Prügel, Josepha; Thom, Ulrike; Steinhoff, Philip O M; Kupryjanowicz, Janusz; Uhl, Gabriele

2015-11-16

Competition between males and their sperm over access to females and their eggs has resulted in manifold ways by which males try to secure paternity, ranging from physically guarding the female after mating to reducing her receptivity or her attractiveness to subsequent males by transferring manipulative substances or by mechanically sealing the female reproductive tract with a copulatory plug. Copulations may also result in internal damage of the female genitalia; however, this is not considered as a direct adaptation against sperm competition but as a collateral effect. Here, we present a drastic and direct mechanism for securing paternity: the removal of coupling structures on female genitalia by males. In the orb-weaving spider Larinia jeskovi males remove the scapus, a crucial coupling device on the female external genital region. Reconstruction of the coupling mechanism using micro-CT-scanned mating pairs revealed that several sclerites of the male genitalia interact to break off the scapus. Once it is removed, remating cannot occur due to mechanical coupling difficulties. In the field, male-inflicted genital damage is very prevalent since all female L. jeskovi were found to be mutilated at the end of the mating season. External genital mutilation is an overlooked but widely spread phenomenon since 80 additional spider species were found for which male genital manipulation can be suspected. Interlocking genitalia provide an evolutionary platform for the rapid evolution of this highly effective mechanism to secure paternity, and we suspect that other animal groups with interlocking genital structures might reveal similarly drastic male adaptations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inelastic Strain and Damage in Surface Instability Tests

NASA Astrophysics Data System (ADS)

Kao, Chu-Shu; Tarokh, Ali; Biolzi, Luigi; Labuz, Joseph F.

2016-02-01

Spalling near a free surface in laboratory experiments on two sandstones was characterized using acoustic emission and digital image correlation. A surface instability apparatus was used to reproduce a state of plane strain near a free surface in a modeled semi-infinite medium subjected to far-field compressive stress. Comparison between AE locations and crack trajectory mapped after the test showed good consistency. Digital image correlation was used to find the displacements in directions parallel (axial direction) and perpendicular (lateral direction) to the free surface at various stages of loading. At a load ratio, LR = current load/peak load, of approximately 30 %, elastic deformation was measured. At 70-80 % LR, the free-face effect started to appear in the displacement contours, especially for the lateral displacement measurements. As the axial compressive stress increased close to peak, extensional lateral strain started to show concentrations associated with localized damage. Continuum damage mechanics was used to describe damage evolution in the surface instability test, and it was shown that a critical value of extensional inelastic strain, on the order of -10-3 for the virgin sandstones, may provide an indicator for determining the onset of surface spalling.

Geo-infrastructure post-flood damage assessment, repair and mitigation strategies : tech transfer summary.

DOT National Transportation Integrated Search

2013-09-01

The 2011 Missouri river flooding caused damage to many geoinfrastructure : systems including levees, bridge abutments/foundations, : paved and unpaved roadways, culverts, and embankment slopes in : western Iowa. The total reported direct cost to repa...

77 FR 28240 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-14

... multiple site damage cracks in the radial web lap and tear strap splices of the aft pressure bulkhead at... multiple site damage cracks in the radial web lap and tear strap splices of the aft pressure bulkhead at...

Micromechanical modeling of short glass-fiber reinforced thermoplastics-Isotropic damage of pseudograins

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

Kammoun, S.; Brassart, L.; Doghri, I.

A micromechanical damage modeling approach is presented to predict the overall elasto-plastic behavior and damage evolution in short fiber reinforced composite materials. The practical use of the approach is for injection molded thermoplastic parts reinforced with short glass fibers. The modeling is proceeded as follows. The representative volume element is decomposed into a set of pseudograins, the damage of which affects progressively the overall stiffness and strength up to total failure. Each pseudograin is a two-phase composite with aligned inclusions having same aspect ratio. A two-step mean-field homogenization procedure is adopted. In the first step, the pseudograins are homogenized individuallymore » according to the Mori-Tanaka scheme. The second step consists in a self-consistent homogenization of homogenized pseudograins. An isotropic damage model is applied at the pseudograin level. The model is implemented as a UMAT in the finite element code ABAQUS. Model is shown to reproduce the strength and the anisotropy (Lankford coefficient) during uniaxial tensile tests on samples cut under different directions relative to the injection flow direction.« less

Micromechanical modeling of short glass-fiber reinforced thermoplastics-Isotropic damage of pseudograins

NASA Astrophysics Data System (ADS)

Kammoun, S.; Brassart, L.; Robert, G.; Doghri, I.; Delannay, L.

2011-05-01

A micromechanical damage modeling approach is presented to predict the overall elasto-plastic behavior and damage evolution in short fiber reinforced composite materials. The practical use of the approach is for injection molded thermoplastic parts reinforced with short glass fibers. The modeling is proceeded as follows. The representative volume element is decomposed into a set of pseudograins, the damage of which affects progressively the overall stiffness and strength up to total failure. Each pseudograin is a two-phase composite with aligned inclusions having same aspect ratio. A two-step mean-field homogenization procedure is adopted. In the first step, the pseudograins are homogenized individually according to the Mori-Tanaka scheme. The second step consists in a self-consistent homogenization of homogenized pseudograins. An isotropic damage model is applied at the pseudograin level. The model is implemented as a UMAT in the finite element code ABAQUS. Model is shown to reproduce the strength and the anisotropy (Lankford coefficient) during uniaxial tensile tests on samples cut under different directions relative to the injection flow direction.

Direct Binding to Replication Protein A (RPA)-coated Single-stranded DNA Allows Recruitment of the ATR Activator TopBP1 to Sites of DNA Damage*

PubMed Central

Acevedo, Julyana; Yan, Shan; Michael, W. Matthew

2016-01-01

A critical event for the ability of cells to tolerate DNA damage and replication stress is activation of the ATR kinase. ATR activation is dependent on the BRCT (BRCA1 C terminus) repeat-containing protein TopBP1. Previous work has shown that recruitment of TopBP1 to sites of DNA damage and stalled replication forks is necessary for downstream events in ATR activation; however, the mechanism for this recruitment was not known. Here, we use protein binding assays and functional studies in Xenopus egg extracts to show that TopBP1 makes a direct interaction, via its BRCT2 domain, with RPA-coated single-stranded DNA. We identify a point mutant that abrogates this interaction and show that this mutant fails to accumulate at sites of DNA damage and that the mutant cannot activate ATR. These data thus supply a mechanism for how the critical ATR activator, TopBP1, senses DNA damage and stalled replication forks to initiate assembly of checkpoint signaling complexes. PMID:27129245

76 FR 72021 - Florida Disaster #FL-00066

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-21

... flooding. Incident Period: 10/28/2011 Through 10/31/2011. Effective Date: 11/14/2011. Physical Loan Application Deadline Date: 01/13/2012. Economic Injury (EIDL) Loan Application Deadline Date: 08/14/2012..., Palm Beach. The Interest Rates are: Percent For Physical Damage: Homeowners With Credit Available...

TU-CD-303-05: Unveiling Tumor Heterogeneity by Molecular Imaging

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

Jeraj, R.

2015-06-15

Recent advances in cancer research have shed new light on the complex processes of how therapeutic radiation initiates changes at cellular, tissue, and system levels that may lead to clinical effects. These new advances may transform the way we use radiation to combat certain types of cancers. For the past two decades many technological advancements in radiation therapy have been largely based on the hypothesis that direct radiation-induced DNA double strand breaks cause cell death and thus tumor control and normal tissue damage. However, new insights have elucidated that in addition to causing cellular DNA damage, localized therapeutic radiation alsomore » initiates cascades of complex downstream biological responses in tissue that extend far beyond where therapeutic radiation dose is directly deposited. For instance, studies show that irradiated dying tumor cells release tumor antigens that can lead the immune system to a systemic anti-cancer attack throughout the body of cancer patient; targeted irradiation to solid tumor also increases the migration of tumor cells already in bloodstream, the seeds of potential metastasis. Some of the new insights may explain the long ago discovered but still unexplained non-localized radiation effects (bystander effect and abscopal effect) and the efficacy of spatially fractionated radiation therapy (microbeam radiation therapy and GRID therapy) where many “hot” and “cold” spots are intentionally created throughout the treatment volume. Better understanding of the mechanisms behind the non-localized radiation effects creates tremendous opportunities to develop new and integrated cancer treatment strategies that are based on radiotherapy, immunology, and chemotherapy. However, in the multidisciplinary effort to advance new radiobiology, there are also tremendous challenges including a lack of multidisciplinary researchers and imaging technologies for the microscopic radiation-induced responses. A better grasp of the essence of these advances in cancer biology research will give medical physicists a new perspective in daily clinical physics practice and in future radiation therapy technological development. Furthermore, academic medical physics should continue to be an integral part of the multidisciplinary cancer research community, harnessing our newly acquired understanding of radiation effects, and developing novel cost-effective treatment strategies to better combat cancer. Learning Objectives: Understand that localized radiation can lead to non-localized secondary effects such as radiation-induced immune response, bystander effect, and abscopal effect. Understand that the non-localized radiation effects may be harnessed to improve cancer treatment. Learn examples of physics participation in multidisciplinary research to advance cancer biology. Recognize the challenges and possibilities of physics applications in cancer research. Chang: NIH 5RC2CA148487-02 and 1U54CA151652-01 Graves: IDEA award (19IB-0106) from the California Breast Cancer Research Program (CBCRP), and by NIH P01 CA67166.« less

TU-CD-303-02: Beyond Radiation Induced Double Strand Breaks - a New Horizon for Radiation Therapy Research

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

Chang, S.

Recent advances in cancer research have shed new light on the complex processes of how therapeutic radiation initiates changes at cellular, tissue, and system levels that may lead to clinical effects. These new advances may transform the way we use radiation to combat certain types of cancers. For the past two decades many technological advancements in radiation therapy have been largely based on the hypothesis that direct radiation-induced DNA double strand breaks cause cell death and thus tumor control and normal tissue damage. However, new insights have elucidated that in addition to causing cellular DNA damage, localized therapeutic radiation alsomore » initiates cascades of complex downstream biological responses in tissue that extend far beyond where therapeutic radiation dose is directly deposited. For instance, studies show that irradiated dying tumor cells release tumor antigens that can lead the immune system to a systemic anti-cancer attack throughout the body of cancer patient; targeted irradiation to solid tumor also increases the migration of tumor cells already in bloodstream, the seeds of potential metastasis. Some of the new insights may explain the long ago discovered but still unexplained non-localized radiation effects (bystander effect and abscopal effect) and the efficacy of spatially fractionated radiation therapy (microbeam radiation therapy and GRID therapy) where many “hot” and “cold” spots are intentionally created throughout the treatment volume. Better understanding of the mechanisms behind the non-localized radiation effects creates tremendous opportunities to develop new and integrated cancer treatment strategies that are based on radiotherapy, immunology, and chemotherapy. However, in the multidisciplinary effort to advance new radiobiology, there are also tremendous challenges including a lack of multidisciplinary researchers and imaging technologies for the microscopic radiation-induced responses. A better grasp of the essence of these advances in cancer biology research will give medical physicists a new perspective in daily clinical physics practice and in future radiation therapy technological development. Furthermore, academic medical physics should continue to be an integral part of the multidisciplinary cancer research community, harnessing our newly acquired understanding of radiation effects, and developing novel cost-effective treatment strategies to better combat cancer. Learning Objectives: Understand that localized radiation can lead to non-localized secondary effects such as radiation-induced immune response, bystander effect, and abscopal effect. Understand that the non-localized radiation effects may be harnessed to improve cancer treatment. Learn examples of physics participation in multidisciplinary research to advance cancer biology. Recognize the challenges and possibilities of physics applications in cancer research. Chang: NIH 5RC2CA148487-02 and 1U54CA151652-01 Graves: IDEA award (19IB-0106) from the California Breast Cancer Research Program (CBCRP), and by NIH P01 CA67166.« less

Increasing Physical Activity and Participation in People With Multiple Sclerosis: A Review.

PubMed

Backus, Deborah

2016-09-01

Multiple sclerosis (MS) is a chronic progressive disease of the central nervous system (CNS) affecting >2.5 million people worldwide. Damage to neurons in the CNS causes various sensorimotor and cognitive symptoms, such as fatigue, pain, spasticity, memory deficits, and impairment of mobility. Until the late 1990s, it was believed that symptoms of MS would be worsened with physical exertion and people with MS were encouraged to limit physical activity and exertion. Not only has emerging evidence suggested that physical activity, including exercise, is safe for people with MS, there is also evidence that at least some of the disability that occurs after MS is due to secondary deconditioning from the sedentary lifestyle adopted because of the symptoms of MS, not just CNS damage alone. Therefore, not only is physical activity safe, it is also required for maintaining function and health in people with MS. The purpose of this article is to review the unique physical and social barriers to physical activity in people with MS, including those with moderate to severe disability who use a wheelchair or scooter for mobility. We will discuss how existing guidelines for physical activity may not meet the needs of people with MS and present evidence-based considerations for promoting physical activity in people with MS. Ultimately, the goal is to overcome the barriers to physical activity and improve health, participation, and quality of life in people with MS. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Mechanisms of DNA damage, repair and mutagenesis

PubMed Central

Chatterjee, Nimrat; Walker, Graham C.

2017-01-01

Living organisms are continuously exposed to a myriad of DNA damaging agents that can impact health and modulate disease-states. However, robust DNA repair and damage-bypass mechanisms faithfully protect the DNA by either removing or tolerating the damage to ensure an overall survival. Deviations in this fine-tuning are known to destabilize cellular metabolic homeostasis, as exemplified in diverse cancers where disruption or deregulation of DNA repair pathways results in genome instability. Because routinely used biological, physical and chemical agents impact human health, testing their genotoxicity and regulating their use have become important. In this introductory review, we will delineate mechanisms of DNA damage and the counteracting repair/tolerance pathways to provide insights into the molecular basis of genotoxicity in cells that lays the foundation for subsequent articles in this issue. PMID:28485537

25 CFR 161.715 - What will BIA do if a trespasser fails to pay penalties, damages and costs?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false What will BIA do if a trespasser fails to pay penalties....715 What will BIA do if a trespasser fails to pay penalties, damages and costs? This section applies if a trespasser fails to pay the assessed penalties, damages, and costs as directed. Unless otherwise...

25 CFR 161.715 - What will BIA do if a trespasser fails to pay penalties, damages and costs?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false What will BIA do if a trespasser fails to pay penalties....715 What will BIA do if a trespasser fails to pay penalties, damages and costs? This section applies if a trespasser fails to pay the assessed penalties, damages, and costs as directed. Unless otherwise...

75 FR 2057 - Airworthiness Directives; Airbus Model A340-200 and A340-300 Series Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-14

... could lead to the loss of the load path for the forward engine mount and damage to other engine mount... loss of the load path for the forward engine mount and damage to other engine mount structures, which... loss of the load path for the forward engine mount and damage to other engine mount structures, which...

Shock-induced damage in rocks: Application to impact cratering

NASA Astrophysics Data System (ADS)

Ai, Huirong

Shock-induced damage beneath impact craters is studied in this work. Two representative terrestrial rocks, San Marcos granite and Bedford limestone, are chosen as test target. Impacts into the rock targets with different combinations of projectile material, size, impact angle, and impact velocity are carried out at cm scale in the laboratory. Shock-induced damage and fracturing would cause large-scale compressional wave velocity reduction in the recovered target beneath the impact crater. The shock-induced damage is measured by mapping the compressional wave velocity reduction in the recovered target. A cm scale nondestructive tomography technique is developed for this purpose. This technique is proved to be effective in mapping the damage in San Marcos granite, and the inverted velocity profile is in very good agreement with the result from dicing method and cut open directly. Both compressional velocity and attenuation are measured in three orthogonal directions on cubes prepared from one granite target impacted by a lead bullet at 1200 m/s. Anisotropy is observed from both results, but the attenuation seems to be a more useful parameter than acoustic velocity in studying orientation of cracks. Our experiments indicate that the shock-induced damage is a function of impact conditions including projectile type and size, impact velocity, and target properties. Combined with other crater phenomena such as crater diameter, depth, ejecta, etc., shock-induced damage would be used as an important yet not well recognized constraint for impact history. The shock-induced damage is also calculated numerically to be compared with the experiments for a few representative shots. The Johnson-Holmquist strength and failure model, initially developed for ceramics, is applied to geological materials. Strength is a complicated function of pressure, strain, strain rate, and damage. The JH model, coupled with a crack softening model, is used to describe both the inelastic response of rocks in the compressive field near the impact source and the tensile failure in the far field. The model parameters are determined either from direct static measurements, or from indirect numerical adjustment. The agreement between the simulation and experiment is very encouraging.

Damage detection based on acceleration data using artificial immune system

NASA Astrophysics Data System (ADS)

Chartier, Sandra; Mita, Akira

2009-03-01

Nowadays, Structural Health Monitoring (SHM) is essential in order to prevent damages occurrence in civil structures. This is a particularly important issue as the number of aged structures is increasing. Damage detection algorithms are often based on changes in the modal properties like natural frequencies, modal shapes and modal damping. In this paper, damage detection is completed by using Artificial Immune System (AIS) theory directly on acceleration data. Inspired from the biological immune system, AIS is composed of several models like negative selection which has a great potential for this study. The negative selection process relies on the fact that T-cells, after their maturation, are sensitive to non self cells and can not detect self cells. Acceleration data were provided by using the numerical model of a 3-story frame structure. Damages were introduced, at particular times, by reduction of story's stiffness. Based on these acceleration data, undamaged data (equivalent to self data) and damaged data (equivalent to non self data) can be obtained and represented in the Hamming shape-space with a binary representation. From the undamaged encoded data, detectors (equivalent to T-cells) are derived and are able to detect damaged encoded data really efficiently by using the rcontiguous bits matching rule. Indeed, more than 95% of detection can be reached when efficient combinations of parameters are used. According to the number of detected data, the localization of damages can even be determined by using the differences between story's relative accelerations. Thus, the difference which presents the highest detection rate, generally up to 89%, is directly linked to the location of damage.

A Thermodynamically Consistent Damage Model for Advanced Composites

NASA Technical Reports Server (NTRS)

Maimi, Pere; Camanho, Pedro P.; Mayugo, Joan-Andreu; Davila, Carlos G.

2006-01-01

A continuum damage model for the prediction of damage onset and structural collapse of structures manufactured in fiber-reinforced plastic laminates is proposed. The principal damage mechanisms occurring in the longitudinal and transverse directions of a ply are represented by a damage tensor that is fixed in space. Crack closure under load reversal effects are taken into account using damage variables established as a function of the sign of the components of the stress tensor. Damage activation functions based on the LaRC04 failure criteria are used to predict the different damage mechanisms occurring at the ply level. The constitutive damage model is implemented in a finite element code. The objectivity of the numerical model is assured by regularizing the dissipated energy at a material point using Bazant's Crack Band Model. To verify the accuracy of the approach, analyses of coupon specimens were performed, and the numerical predictions were compared with experimental data.

Micromechanics-Based Damage Analysis of Fracture in Ti5553 Alloy with Application to Bolted Sectors

NASA Astrophysics Data System (ADS)

Bettaieb, Mohamed Ben; Van Hoof, Thibaut; Minnebo, Hans; Pardoen, Thomas; Dufour, Philippe; Jacques, Pascal J.; Habraken, Anne Marie

2015-03-01

A physics-based, uncoupled damage model is calibrated using cylindrical notched round tensile specimens made of Ti5553 and Ti-6Al-4V alloys. The fracture strain of Ti5553 is lower than for Ti-6Al-4V in the full range of stress triaxiality. This lower ductility originates from a higher volume fraction of damage sites. By proper heat treatment, the fracture strain of Ti5553 increases by almost a factor of two, as a result of a larger damage nucleation stress. This result proves the potential for further optimization of the damage resistance of the Ti5553 alloy. The damage model is combined with an elastoviscoplastic law in order to predict failure in a wide range of loading conditions. In particular, a specific application involving bolted sectors is addressed in order to determine the potential of replacing the Ti-6Al-4V by the Ti5553 alloy.

SITE AMPLIFICATION OF EARTHQUAKE GROUND MOTION.

USGS Publications Warehouse

Hays, Walter W.

1986-01-01

When analyzing the patterns of damage in an earthquake, physical parameters of the total earthquake-site-structure system are correlated with the damage. Soil-structure interaction, the cause of damage in many earthquakes, involves the frequency-dependent response of both the soil-rock column and the structure. The response of the soil-rock column (called site amplification) is controversial because soil has strain-dependent properties that affect the way the soil column filters the input body and surface seismic waves, modifying the amplitude and phase spectra and the duration of the surface ground motion.

Damage assessment in multilayered MEMS structures under thermal fatigue

NASA Astrophysics Data System (ADS)

Maligno, A. R.; Whalley, D. C.; Silberschmidt, V. V.

2011-07-01

This paper reports on the application of a Physics of Failure (PoF) methodology to assessing the reliability of a micro electro mechanical system (MEMS). Numerical simulations, based on the finite element method (FEM) using a sub-domain approach was used to examine the damage onset due to temperature variations (e.g. yielding of metals which may lead to thermal fatigue). In this work remeshing techniques were employed in order to develop a damage tolerance approach based on the assumption that initial flaws exist in the multi-layered.

A Green's Function Approach to Simulate DNA Damage by the Indirect Effect

NASA Technical Reports Server (NTRS)

Plante, Ianik; Cicinotta, Francis A.

2013-01-01

The DNA damage is of fundamental importance in the understanding of the effects of ionizing radiation. DNA is damaged by the direct effect of radiation (e.g. direct ionization) and by indirect effect (e.g. damage by.OH radicals created by the radiolysis of water). Despite years of research, many questions on the DNA damage by ionizing radiation remains. In the recent years, the Green's functions of the diffusion equation (GFDE) have been used extensively in biochemistry [1], notably to simulate biochemical networks in time and space [2]. In our future work on DNA damage, we wish to use an approach based on the GFDE to refine existing models on the indirect effect of ionizing radiation on DNA. To do so, we will use the code RITRACKS [3] developed at the NASA Johnson Space Center to simulate the radiation track structure and calculate the position of radiolytic species after irradiation. We have also recently developed an efficient Monte-Carlo sampling algorithm for the GFDE of reversible reactions with an intermediate state [4], which can be modified and adapted to simulate DNA damage by free radicals. To do so, we will use the known reaction rate constants between radicals (OH, eaq, H,...) and the DNA bases, sugars and phosphates and use the sampling algorithms to simulate the diffusion of free radicals and chemical reactions with DNA. These techniques should help the understanding of the contribution of the indirect effect in the formation of DNA damage and double-strand breaks.

Involvement of oxidatively damaged DNA and repair in cancer development and aging

PubMed Central

Tudek, Barbara; Winczura, Alicja; Janik, Justyna; Siomek, Agnieszka; Foksinski, Marek; Oliński, Ryszard

2010-01-01

DNA damage and DNA repair may mediate several cellular processes, like replication and transcription, mutagenesis and apoptosis and thus may be important factors in the development and pathology of an organism, including cancer. DNA is constantly damaged by reactive oxygen species (ROS) and reactive nitrogen species (RNS) directly and also by products of lipid peroxidation (LPO), which form exocyclic adducts to DNA bases. A wide variety of oxidatively-generated DNA lesions are present in living cells. 8-oxoguanine (8-oxoGua) is one of the best known DNA lesions due to its mutagenic properties. Among LPO-derived DNA base modifications the most intensively studied are ethenoadenine and ethenocytosine, highly miscoding DNA lesions considered as markers of oxidative stress and promutagenic DNA damage. Although at present it is impossible to directly answer the question concerning involvement of oxidatively damaged DNA in cancer etiology, it is likely that oxidatively modified DNA bases may serve as a source of mutations that initiate carcinogenesis and are involved in aging (i.e. they may be causal factors responsible for these processes). To counteract the deleterious effect of oxidatively damaged DNA, all organisms have developed several DNA repair mechanisms. The efficiency of oxidatively damaged DNA repair was frequently found to be decreased in cancer patients. The present work reviews the basis for the biological significance of DNA damage, particularly effects of 8-oxoGua and ethenoadduct occurrence in DNA in the aspect of cancer development, drawing attention to the multiplicity of proteins with repair activities. PMID:20589166

The comparison of DNA damage induced by micro DBD plasma and low energy electron for curing human diseases

NASA Astrophysics Data System (ADS)

Park, Yeunsoo

2015-09-01

It is well known that low energy electrons (LEE, especially below 10 eV) can generate DNA damage via indirect action named dissociative electron attachment (DEA). We can now explain some parts of the exact mechanism on DNA damage by LEE collision with direct ionization effect when cancer patients get the radiotherapy. It is kind of remarkable information in the field of radiation therapy. However, it is practically very difficult to directly apply this finding to human disease cure due to difficulty of LEE therapy actualization and request of further clinical studies. Recently, there is a novel challenge in plasma application, that is, how we can apply plasma technology to diagnosis and treatment of many serious diseases like cancer. Cold atmospheric pressure plasma (CAPP) is a very good source to apply to plasma medicine and bio-applications because of low temperature, low cost, and easy handling. Some scientists have already reported good results related to clinical plasma application. The purposes of this study are to further find out exact mechanisms of DNA damage by LEE at the molecular level, to verify new DNA damage like structural alteration on DNA subunits and to compare DNA damage by LEE and plasma source. We will keep expanding our study to DNA damage by plasma source to develop plasma-based new medical and biological applications. We will show some recent results, DNA damage by LEE and non-thermal plasma.

Numerical-experimental investigation of load paths in DP800 dual phase steel during Nakajima test

NASA Astrophysics Data System (ADS)

Bergs, Thomas; Nick, Matthias; Feuerhack, Andreas; Trauth, Daniel; Klocke, Fritz

2018-05-01

Fuel efficiency requirements demand lightweight construction of vehicle body parts. The usage of advanced high strength steels permits a reduction of sheet thickness while still maintaining the overall strength required for crash safety. However, damage, internal defects (voids, inclusions, micro fractures), microstructural defects (varying grain size distribution, precipitates on grain boundaries, anisotropy) and surface defects (micro fractures, grooves) act as a concentration point for stress and consequently as an initiation point for failure both during deep drawing and in service. Considering damage evolution in the design of car body deep drawing processes allows for a further reduction in material usage and therefore body weight. Preliminary research has shown that a modification of load paths in forming processes can help mitigate the effects of damage on the material. This paper investigates the load paths in Nakajima tests of a DP800 dual phase steel to research damage in deep drawing processes. Investigation is done via a finite element model using experimentally validated material data for a DP800 dual phase steel. Numerical simulation allows for the investigation of load paths with respect to stress states, strain rates and temperature evolution, which cannot be easily observed in physical experiments. Stress triaxiality and the Lode parameter are used to describe the stress states. Their evolution during the Nakajima tests serves as an indicator for damage evolution. The large variety of sheet metal forming specific load paths in Nakajima tests allows a comprehensive evaluation of damage for deep drawing. The results of the numerical simulation conducted in this project and further physical experiments will later be used to calibrate a damage model for simulation of deep drawing processes.

BioSentinel: Mission Development of a Radiation Biosensor to Gauge DNA Damage and Repair Beyond Low Earth Orbit on a 6U Nanosatellite.

NASA Technical Reports Server (NTRS)

Lewis, Brian; Hanel, Robert; Bhattacharya, Sharmila; Ricco, Antonion J.; Agasid, Elwood; Reiss-Bubenheim, Debra; Straume, Tore; Parra, Macerena; Boone, Travis; Santa Maria, Sergio;

Semiochemicals to monitor insect pests – future opportunities for an effective host plant volatile blend to attract navel orangeworm in pistachio orchards

USDA-ARS?s Scientific Manuscript database

The navel orangeworm (Amyelois transitella) has been a major insect pest of California tree nut orchards for the past five decades. In particular, almond and pistachio orchards suffer major annual economic damage due to both physical and associated fungal damage caused by navel orangeworm larvae. Un...

Spectroscopic Axonal Damage of the Right Locus Coeruleus Relates to Selective Attention Impairment in Early Stage Relapsing-Remitting Multiple Sclerosis

ERIC Educational Resources Information Center

Gadea, Marien; Martinez-Bisbal, M. Carmen; Marti-Bonmati, Luis; Espert, Raul; Casanova, Bonaventura; Coret, Francisco; Celda, Bernardo

2004-01-01

Lower levels of N-acetylaspartate (NAA), a marker of axonal damage, have been found in the normal-appearing white matter (NAWM) of relapsing-remitting multiple sclerosis (RRMS) patients with low physical disability. However, its relation to the clinical status of these patients remains unclear. We explored the association between NAA levels…

RAD18 and associated proteins are immobilized in nuclear foci in human cells entering S-phase with ultraviolet light-induced damage

PubMed Central

Watson, Nicholas B.; Nelson, Eric; Digman, Michelle; Thornburg, Joshua A.; Alphenaar, Bruce W.; McGregor, W. Glenn

2008-01-01

Proteins required for translesion DNA synthesis localize in nuclear foci of cells with replication-blocking lesions. The dynamics of this process were examined in human cells with fluorescence-based biophysical techniques. Photobleaching recovery and raster image correlation spectroscopy experiments indicated that involvement in the nuclear foci reduced the movement of RAD18 from diffusion-controlled to virtual immobility. Examination of the mobility of REV1 indicated that it is similarly immobilized when it is observed in nuclear foci. Reducing the level of RAD18 greatly reduced the focal accumulation of REV1 and reduced UV mutagenesis to background frequencies. Fluorescence lifetime measurements indicated that RAD18 and RAD6A or polη only transferred resonance energy when these proteins colocalized in damage-induced nuclear foci, indicating a close physical association only within such foci. Our data support a model in which RAD18 within damage-induced nuclear foci is immobilized and is required for recruitment of Y-family DNA polymerases and subsequent mutagenesis. In the absence of damage these proteins are not physically associated within the nucleoplasm. PMID:18926833

Impact Cratering Physics al Large Planetary Scales

NASA Astrophysics Data System (ADS)

Ahrens, Thomas J.

2007-06-01

Present understanding of the physics controlling formation of ˜10^3 km diameter, multi-ringed impact structures on planets were derived from the ideas of Scripps oceanographer, W. Van Dorn, University of London's, W, Murray, and, Caltech's, D. O'Keefe who modeled the vertical oscillations (gravity and elasticity restoring forces) of shock-induced melt and damaged rock within the transient crater immediately after the downward propagating hemispheric shock has processed rock (both lining, and substantially below, the transient cavity crater). The resulting very large surface wave displacements produce the characteristic concentric, multi-ringed basins, as stored energy is radiated away and also dissipated upon inducing further cracking. Initial calculational description, of the above oscillation scenario, has focused upon on properly predicting the resulting density of cracks, and, their orientations. A new numerical version of the Ashby--Sammis crack damage model is coupled to an existing shock hydrodynamics code to predict impact induced damage distributions in a series of 15--70 cm rock targets from high speed impact experiments for a range of impactor type and velocity. These are compared to results of crack damage distributions induced in crustal rocks with small arms impactors and mapped ultrasonically in recent Caltech experiments (Ai and Ahrens, 2006).

Effects of thermal and moisture cycling on the internal structure of stitched RTM laminates

NASA Technical Reports Server (NTRS)

Walker, Jeff; Roundy, Lance; Goering, Jon

1993-01-01

Conventional aerospace composites are strong and stiff in the directions parallel to the carbon fibers, but they are prone to delaminations and damage in the through-the-thickness directions. Recent research has shown that substantial improvements in damage tolerance are obtained from textile composites with Z-direction reinforcement provided by stitching, weaving, or braiding. Because of the mismatch in thermal and moisture expansion properties of the various material components, there is a potential for microcracks to develop in the resin matrix. These cracks can form to relieve the mechanical stresses that are generated during curing or in-service temperature cycles.

NBIC: National Ballast Information Clearinghouse

Science.gov Websites

, incidental, direct, indirect, special, punitive, or consequential damages, loss of use, loss of data, loss of income or profit, loss of or damage to property, claims of third parties, or other losses of any kind or

Structural Damage Detection Using Slopes of Longitudinal Vibration Shapes

DOE PAGES

Xu, W.; Zhu, W. D.; Smith, S. A.; ...

2016-03-18

While structural damage detection based on flexural vibration shapes, such as mode shapes and steady-state response shapes under harmonic excitation, has been well developed, little attention is paid to that based on longitudinal vibration shapes that also contain damage information. This study originally formulates a slope vibration shape for damage detection in bars using longitudinal vibration shapes. To enhance noise robustness of the method, a slope vibration shape is transformed to a multiscale slope vibration shape in a multiscale domain using wavelet transform, which has explicit physical implication, high damage sensitivity, and noise robustness. These advantages are demonstrated in numericalmore » cases of damaged bars, and results show that multiscale slope vibration shapes can be used for identifying and locating damage in a noisy environment. A three-dimensional (3D) scanning laser vibrometer is used to measure the longitudinal steady-state response shape of an aluminum bar with damage due to reduced cross-sectional dimensions under harmonic excitation, and results show that the method can successfully identify and locate the damage. Slopes of longitudinal vibration shapes are shown to be suitable for damage detection in bars and have potential for applications in noisy environments.« less

Space Shuttle STS-1 SRB damage investigation

NASA Technical Reports Server (NTRS)

Nevins, C. D.

1982-01-01

The physical damage incurred by the solid rocket boosters during reentry on the initial space shuttle flight raised the question of whether the hardware, as designed, would yield the low cost per flight desired. The damage was quantified, the cause determined and specific design changes recommended which would preclude recurrence. Flight data, postflight analyses, and laboratory hardware examinations were used. The resultant findings pointed to two principal causes: failure of the aft skirt thermal curtain at the onset of reentry aerodynamic heating, and overloading of the aft shirt stiffening rings during water impact. Design changes were recommended on both the thermal curtain and the aft skirt structural members to prevent similar damage on future missions.

Origins and consequences of DNA damage in male germ cells.

PubMed

Aitken, R John; De Iuliis, Geoffry N

2007-06-01

DNA damage in the male germline is associated with poor fertilization rates following IVF, defective preimplantation embryonic development, and high rates of miscarriage and morbidity in the offspring, including childhood cancer. This damage is poorly characterized, but is known to involve hypomethylation of key genes, oxidative base damage, endonuclease-mediated cleavage and the formation of adducts with xenobiotics and the products of lipid peroxidation. There are many possible causes of such DNA damage, including abortive apoptosis, the oxidative stress associated with male genital tract infection, exposure to redox cycling chemicals, and defects of spermiogenesis associated with the retention of excess residual cytoplasm. Physical factors such as exposure to radiofrequency electromagnetic radiation or mild scrotal heating can also induce DNA damage in mammalian spermatozoa, although the underlying mechanisms are unclear. Ultimately, resolving the precise nature of the DNA lesions present in the spermatozoa of infertile men will be an important step towards uncovering the aetiology of this damage and developing strategies for its clinical management.

Novel high-fidelity realistic explosion damage simulation for urban environments

NASA Astrophysics Data System (ADS)

Liu, Xiaoqing; Yadegar, Jacob; Zhu, Youding; Raju, Chaitanya; Bhagavathula, Jaya

2010-04-01

Realistic building damage simulation has a significant impact in modern modeling and simulation systems especially in diverse panoply of military and civil applications where these simulation systems are widely used for personnel training, critical mission planning, disaster management, etc. Realistic building damage simulation should incorporate accurate physics-based explosion models, rubble generation, rubble flyout, and interactions between flying rubble and their surrounding entities. However, none of the existing building damage simulation systems sufficiently faithfully realize the criteria of realism required for effective military applications. In this paper, we present a novel physics-based high-fidelity and runtime efficient explosion simulation system to realistically simulate destruction to buildings. In the proposed system, a family of novel blast models is applied to accurately and realistically simulate explosions based on static and/or dynamic detonation conditions. The system also takes account of rubble pile formation and applies a generic and scalable multi-component based object representation to describe scene entities and highly scalable agent-subsumption architecture and scheduler to schedule clusters of sequential and parallel events. The proposed system utilizes a highly efficient and scalable tetrahedral decomposition approach to realistically simulate rubble formation. Experimental results demonstrate that the proposed system has the capability to realistically simulate rubble generation, rubble flyout and their primary and secondary impacts on surrounding objects including buildings, constructions, vehicles and pedestrians in clusters of sequential and parallel damage events.

Skeletal Muscle Cell Damage Indicators in Volleyball Players after the Competitive Phase of the Annual Training Cycle.

PubMed

Radojewski, Mateusz; Podgórski, Tomasz; Pospieszna, Barbara; Kryściak, Jakub; Śliwicka, Ewa; Karolkiewicz, Joanna

2018-06-01

The aim of the study was to evaluate the impact of the competitive phase on physiological and metabolic indices and selected markers of skeletal muscle damage in male volleyball players. The study group consisted of 24 young male volleyball players. During the study, participants underwent two series of measurements, before and after the competitive phase of the annual training cycle. In both study terms, players performed an incremental treadmill running test to determine their ventilatory threshold and maximal oxygen uptake. Venous and capillary blood samples were taken for biochemical analysis. There was no significant difference in the physical fitness level, values of biochemical variables and the level of antioxidant status in the surveyed athletes between the two study terms. Significant changes within skeletal muscle damage markers were observed between the beginning and the end of the competitive period: an increase in the concentration of cellular DNA damage products (8-hydroxy-2'-deoxyguanosine; p < 0.0001) and a decrease in muscle activity of creatine kinase (p<0.05). In spite of the increment in cell damage markers, the unaffected level of physiological and biochemical markers may indicate that the experienced cell destruction did not negatively affect the level of physical fitness. When designing the annual training plan, coaches and athletes need to take into consideration that temporary physiological states - oxidative stress and inflammation - may be required to attain training adaptation.

Continuum theory of fibrous tissue damage mechanics using bond kinetics: application to cartilage tissue engineering.

PubMed

Nims, Robert J; Durney, Krista M; Cigan, Alexander D; Dusséaux, Antoine; Hung, Clark T; Ateshian, Gerard A

2016-02-06

This study presents a damage mechanics framework that employs observable state variables to describe damage in isotropic or anisotropic fibrous tissues. In this mixture theory framework, damage is tracked by the mass fraction of bonds that have broken. Anisotropic damage is subsumed in the assumption that multiple bond species may coexist in a material, each having its own damage behaviour. This approach recovers the classical damage mechanics formulation for isotropic materials, but does not appeal to a tensorial damage measure for anisotropic materials. In contrast with the classical approach, the use of observable state variables for damage allows direct comparison of model predictions to experimental damage measures, such as biochemical assays or Raman spectroscopy. Investigations of damage in discrete fibre distributions demonstrate that the resilience to damage increases with the number of fibre bundles; idealizing fibrous tissues using continuous fibre distribution models precludes the modelling of damage. This damage framework was used to test and validate the hypothesis that growth of cartilage constructs can lead to damage of the synthesized collagen matrix due to excessive swelling caused by synthesized glycosaminoglycans. Therefore, alternative strategies must be implemented in tissue engineering studies to prevent collagen damage during the growth process.

Continuum theory of fibrous tissue damage mechanics using bond kinetics: application to cartilage tissue engineering

PubMed Central

Nims, Robert J.; Durney, Krista M.; Cigan, Alexander D.; Hung, Clark T.; Ateshian, Gerard A.

2016-01-01

This study presents a damage mechanics framework that employs observable state variables to describe damage in isotropic or anisotropic fibrous tissues. In this mixture theory framework, damage is tracked by the mass fraction of bonds that have broken. Anisotropic damage is subsumed in the assumption that multiple bond species may coexist in a material, each having its own damage behaviour. This approach recovers the classical damage mechanics formulation for isotropic materials, but does not appeal to a tensorial damage measure for anisotropic materials. In contrast with the classical approach, the use of observable state variables for damage allows direct comparison of model predictions to experimental damage measures, such as biochemical assays or Raman spectroscopy. Investigations of damage in discrete fibre distributions demonstrate that the resilience to damage increases with the number of fibre bundles; idealizing fibrous tissues using continuous fibre distribution models precludes the modelling of damage. This damage framework was used to test and validate the hypothesis that growth of cartilage constructs can lead to damage of the synthesized collagen matrix due to excessive swelling caused by synthesized glycosaminoglycans. Therefore, alternative strategies must be implemented in tissue engineering studies to prevent collagen damage during the growth process. PMID:26855751

Overview of the SHIELDS Project at LANL

NASA Astrophysics Data System (ADS)

Jordanova, V.; Delzanno, G. L.; Henderson, M. G.; Godinez, H. C.; Jeffery, C. A.; Lawrence, E. C.; Meierbachtol, C.; Moulton, D.; Vernon, L.; Woodroffe, J. R.; Toth, G.; Welling, D. T.; Yu, Y.; Birn, J.; Thomsen, M. F.; Borovsky, J.; Denton, M.; Albert, J.; Horne, R. B.; Lemon, C. L.; Markidis, S.; Young, S. L.

2015-12-01

The near-Earth space environment is a highly dynamic and coupled system through a complex set of physical processes over a large range of scales, which responds nonlinearly to driving by the time-varying solar wind. Predicting variations in this environment that can affect technologies in space and on Earth, i.e. "space weather", remains a big space physics challenge. We present a recently funded project through the Los Alamos National Laboratory (LANL) Directed Research and Development (LDRD) program that is developing a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. The project goals are to specify the dynamics of the hot (keV) particles (the seed population for the radiation belts) on both macro- and micro-scale, including important physics of rapid particle injection and acceleration associated with magnetospheric storms/substorms and plasma waves. This challenging problem is addressed using a team of world-class experts in the fields of space science and computational plasma physics and state-of-the-art models and computational facilities. New data assimilation techniques employing data from LANL instruments on the Van Allen Probes and geosynchronous satellites are developed in addition to physics-based models. This research will provide a framework for understanding of key radiation belt drivers that may accelerate particles to relativistic energies and lead to spacecraft damage and failure. The ability to reliably distinguish between various modes of failure is critically important in anomaly resolution and forensics. SHIELDS will enhance our capability to accurately specify and predict the near-Earth space environment where operational satellites reside.

Telomeres, Nutrition, and Longevity: Can We Really Navigate Our Aging?

PubMed

Vidacek, Nikolina Škrobot; Nanic, Lucia; Ravlic, Sanda; Sopta, Mary; Geric, Marko; Gajski, Goran; Garaj-Vrhovac, Vera; Rubelj, Ivica

2017-12-12

Telomeres are dynamic chromosome-end structures that serve as guardians of genome stability. They are known to be one of the major determinants of aging and longevity in higher mammals. Studies have demonstrated a direct correlation between telomere length and life expectancy, stress, DNA damage, and onset of aging-related diseases. This review discusses the most important factors that influence our telomeres. Various genetic and environmental factors such as diet, physical activity, obesity, and stress are known to influence health and longevity as well as telomere dynamics. Individuals currently have the opportunity to modulate the dynamics of their aging and health span, monitor these processes, and even make future projections by following their telomere dynamics. As telomeres react to positive as well as negative health factors, we should be able to directly influence our telomere metabolism, slow their deterioration, and diminish our aging and perhaps extend our life and health span. © The Author(s) 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Peripheral Pain Enhances the Effects of Incentive Downshifts

ERIC Educational Resources Information Center

Ortega, Leonardo A.; Daniel, Alan M.; Davis, Jessica B.; Fuchs, Perry N.; Papini, Mauricio R.

2011-01-01

Physical pain (induced by tissue damage) and psychological pain (induced by surprising incentive loss) share a set of common neural substrates, but little is known about their interactions. The present research studied such interactions using the formalin test to induce physical pain and consummatory successive negative contrast (cSNC) to induce…

Questionable Supervision by Physical Educators

ERIC Educational Resources Information Center

Sawyer, Thomas H.; Gimbert, Tonya L.

2013-01-01

According to Court records, student Pedro Godoy (Godoy) filed a suit against the school district (Central Islip Union Free School District) and teacher Otis R. Scerbo (Scerbo), seeking to recover damages for personal injuries allegedly sustained by Godoy while participating in a game of floor hockey during physical education class. Scerbo (the…

Fundamental Studies in the Molecular Basis of Laser Induced Retinal Damage

DTIC Science & Technology

1988-01-01

Cornell University School of Applied & Engineering Physics Ithaca, NY 14853 DOD DISTRIBUTION STATEMENT Approved for public release; distribution unlimited...Code) 7b. ADDRESS (City, State, and ZIP Code) School of Applied & Engineering Physics Ithaca, NY 14853 8a. NAME OF FUNDING/SPONSORING Bb. OFFICE SYMBOL

Fundamental Studies in the Molecular Basis of Laser Induced Retinal Damage

DTIC Science & Technology

1988-01-01

Cornell University .LECT l School of Applied & Engineering PhysicsIthaca, NY 14853 0 JAN 198D DOD DISTRIBUTION STATEMENT Approved for public release...State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) School of Applied & Engineering Physics Ithaca, NY 14853 Ba. NAME OF FUNDING/ SPONSORING

The Abusive Environment and the Child's Adaptation.

ERIC Educational Resources Information Center

Martin, Harold P.

The biologic and developmental problems of abused children are usually thought of etiologically in relation to the physical trauma which has been suffered. Indeed, physical trauma can cause death, brain damage, developmental delays and deviations in personality development. The environment in which the abused child grows and develops is a most…

Energy and Global Ethics.

ERIC Educational Resources Information Center

Reader, Mark

1979-01-01

Author believes that the nuclear fuel cycle is damaging to our health, physical system, ecosystem, and social system. He recommends reversing the trend toward nuclear power and solving the energy crisis by creating a global society able to live in balance with its physical environment. Journal available from 7 Harwood Drive, Amherst, New York…

Disintegration of cruciform and G-quadruplex structures during the course of helicase-dependent amplification (HDA).

PubMed

Li, Dawei; Lv, Bei; Zhang, Hao; Lee, Jasmine Yiqin; Li, Tianhu

2015-04-15

Unlike chemical damages on DNA, physical alterations of B-form of DNA occur commonly in organisms that serve as signals for specified cellular events. Although the modes of action for repairing of chemically damaged DNA have been well studied nowadays, the repairing mechanisms for physically altered DNA structures have not yet been understood. Our current in vitro studies show that both breakdown of stable non-B DNA structures and resumption of canonical B-conformation of DNA can take place during the courses of isothermal helicase-dependent amplification (HDA). The pathway that makes the non-B DNA structures repairable is presumably the relieving of the accumulated torsional stress that was caused by the positive supercoiling. Our new findings suggest that living organisms might have evolved this distinct and economical pathway for repairing their physically altered DNA structures. Copyright © 2015 Elsevier Ltd. All rights reserved.

INTERNATIONAL CONFERENCE ON ULTRASHORT HIGH-ENERGY RADIATION AND MATTER

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

Wootton, A J

2004-01-15

The workshop is intended as a forum to discuss the latest experimental, theoretical and computational results related to the interaction of high energy radiation with matter. High energy is intended to mean soft x-ray and beyond, but important new results from visible systems will be incorporated. The workshop will be interdisciplinary amongst scientists from many fields, including: plasma physics; x-ray physics and optics; solid state physics and material science; biology ; quantum optics. Topics will include, among other subjects: understanding damage thresholds for x-ray interactions with matter developing {approx} 5 keV x-ray sources to investigate damage; developing {approx} 100 keVmore » Thomsom sources for material studies; developing short pulse (100 fs and less) x-ray diagnostics; developing novel X-ray optics; and developing models for the response of biological samples to ultra intense, sub ps x-rays high-energy radiation.« less

Inflammatory, autoimmune, chronic diseases: bad diet and physical inactivity are causes or effects?

PubMed

Gracia, M C

2006-01-01

It is now well established that most chronic diseases, especially those identified as inflammatory, are statistically correlated with some typical dietary excesses and physical inactivity. But do really these habits cause the diseases, or they result from them? Current opinion favours the first option, but fails to explain why the satisfaction of eating, naturally evolved in our brains to produce health, apparently induces countless millions of people to eat unrestrictedly until becoming mortally sick, whereas trying to keep a theoretically healthy diet is most often a real torture. The inverse explanation makes much more sense: since inflammation produces much heat, calorie-rich diets are required. An inflamed digestive tract lacks digestive power and is easily irritated or damaged by solid objects, therefore requiring a refined, concentrated, low-fibre diet. And inflamed or merely sick organisms are easily exhausted by physical effort, hence physical inactivity. This study confirms that, most probably, the primary causes of inflammatory diseases are always external inflammatory agents, like infectious micro-organisms or toxic substances, of which a particularly ubiquitous example is nicotine. High-calorie/low-fibre diets and physical inactivity are direct consequences of generalised inflammation. Inversely, in most cases, physical exercise and moderation in eating, by themselves, cannot substantially suppress inflammations, but they can prevent them from being further reinforced by the neural reward system. Moreover, diets and exercise causing important suffering will usually do more harm than good, especially to children and young people, not to mention pregnant or nursing women. Only the identification and elimination of the inflammatory agents can efficiently prevent and cure inflammatory diseases, and currently nicotine, absorbed intentionally or passively, from tobacco or other sources, must be considered the chief suspect because of its inflammatory power, ubiquity and addictive properties.

Flood risk assessment and mapping for the Lebanese watersheds

NASA Astrophysics Data System (ADS)

Abdallah, Chadi; Hdeib, Rouya

2016-04-01

Of all natural disasters, floods affect the greatest number of people worldwide and have the greatest potential to cause damage. Nowadays, with the emerging global warming phenomenon, this number is expected to increase. The Eastern Mediterranean area, including Lebanon (10452 Km2, 4.5 M habitant), has witnessed in the past few decades an increase frequency of flooding events. This study profoundly assess the flood risk over Lebanon covering all the 17 major watersheds and a number of small sub-catchments. It evaluate the physical direct tangible damages caused by floods. The risk assessment and evaluation process was carried out over three stages; i) Evaluating Assets at Risk, where the areas and assets vulnerable to flooding are identified, ii) Vulnerability Assessment, where the causes of vulnerability are assessed and the value of the assets are provided, iii) Risk Assessment, where damage functions are established and the consequent damages of flooding are estimated. A detailed Land CoverUse map was prepared at a scale of 1/ 1 000 using 0.4 m resolution satellite images within the flood hazard zones. The detailed field verification enabled to allocate and characterize all elements at risk, identify hotspots, interview local witnesses, and to correlate and calibrate previous flood damages with the utilized models. All filed gathered information was collected through Mobile Application and transformed to be standardized and classified under GIS environment. Consequently; the general damage evaluation and risk maps at different flood recurrence periods (10, 50, 100 years) were established. Major results showed that floods in a winter season (December, January, and February) of 10 year recurrence and of water retention ranging from 1 to 3 days can cause total damages (losses) that reach 1.14 M for crop lands and 2.30 M for green houses. Whereas, it may cause 0.2 M to losses in fruit trees for a flood retention ranging from 3 to 5 days. These numbers differs according to the flooding season, cultivation type and the agro-climatic zone. The flood damage equivalence to constructions summed up to reach 32 M for residential structures, 29 M for non-residential structures, and 5 M for the Syrian refugees tents, while structures' content losses were estimated at 27M, 54M, 7 M respectively for the same flood frequency. The total length of affected road networks during flooding is 1589km with an estimated cost of 565M. The total number of affected population reached 82,000 while the number of effected vehicles is 62,000 for a 50year recurrence period

Destructive behavior of iron oxide in projectile impact

NASA Astrophysics Data System (ADS)

Shang, Wang; Xiaochen, Wang; Quan, Yang; Zhongde, Shan

2017-12-01

The damage strain values of Q235-A surface oxide scale were obtained by scanning electron microscopy (SEM/EDS) and universal tensile testing machine. The finite element simulation was carried out to study the destruction effects of oxidation at different impact rates. The results show that the damage value of the oxide strain is 0.08%. With the increase of the projectile velocity, the damage area of the oxide scale is increased, and the damage area is composed of the direct destruction area and the indirect failure area. The indirect damage area is caused by the stress/strain to the surrounding expansion after the impact of the steel body.

Precision Crystal Calorimeters in High Energy Physics

ScienceCinema

Ren-Yuan Zhu

2017-12-09

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal’s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

Damage-Free Relief-Valve Disassembly

NASA Technical Reports Server (NTRS)

Haselmaier, H.

1986-01-01

Tool safely disassembles relief valves without damage to sensitive parts. Relief-valve disassembly tool used to extract valve nozzle from its housing. Holding device on tool grops nozzle. When user strikes hammer against impact disk, holding device pulls nozzle from press fit. Previously, nozzle dislodged by striking spindle above it, but practice often damaged retaining screw. New tool removes nozzle directly. With minor modifications, tool adapted to valves from different manufacturers.

Progressive Damage and Fracture in Composites Under Dynamic Loading

NASA Technical Reports Server (NTRS)

Minnetyan, Levon

1994-01-01

A computational simulation tool is used to evaluate the various stages of damage progression in composite materials during losipescu shear testing. Unidirectional composite specimens with either the major or minor material axis in the load direction are considered. Damage progression characteristics are described for each specimen using two types of boundary conditions. A procedure is outlined regarding the use of computational simulation in the testing of composite materials.

Specification of the Surface Charging Environment with SHIELDS

NASA Astrophysics Data System (ADS)

Jordanova, V.; Delzanno, G. L.; Henderson, M. G.; Godinez, H. C.; Jeffery, C. A.; Lawrence, E. C.; Meierbachtol, C.; Moulton, J. D.; Vernon, L.; Woodroffe, J. R.; Brito, T.; Toth, G.; Welling, D. T.; Yu, Y.; Albert, J.; Birn, J.; Borovsky, J.; Denton, M.; Horne, R. B.; Lemon, C.; Markidis, S.; Thomsen, M. F.; Young, S. L.

2016-12-01

Predicting variations in the near-Earth space environment that can lead to spacecraft damage and failure, i.e. "space weather", remains a big space physics challenge. A recently funded project through the Los Alamos National Laboratory (LANL) Directed Research and Development (LDRD) program aims at developing a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. The project goals are to understand the dynamics of the surface charging environment (SCE), the hot (keV) electrons representing the source and seed populations for the radiation belts, on both macro- and microscale. Important physics questions related to rapid particle injection and acceleration associated with magnetospheric storms and substorms as well as plasma waves are investigated. These challenging problems are addressed using a team of world-class experts in the fields of space science and computational plasma physics, and state-of-the-art models and computational facilities. In addition to physics-based models (like RAM-SCB, BATS-R-US, and iPIC3D), new data assimilation techniques employing data from LANL instruments on the Van Allen Probes and geosynchronous satellites are developed. Simulations with the SHIELDS framework of the near-Earth space environment where operational satellites reside are presented. Further model development and the organization of a "Spacecraft Charging Environment Challenge" by the SHIELDS project at LANL in collaboration with the NSF Geospace Environment Modeling (GEM) Workshop and the multi-agency Community Coordinated Modeling Center (CCMC) to assess the accuracy of SCE predictions are discussed.

Statistical physics of vaccination

NASA Astrophysics Data System (ADS)

Wang, Zhen; Bauch, Chris T.; Bhattacharyya, Samit; d'Onofrio, Alberto; Manfredi, Piero; Perc, Matjaž; Perra, Nicola; Salathé, Marcel; Zhao, Dawei

2016-12-01

Historically, infectious diseases caused considerable damage to human societies, and they continue to do so today. To help reduce their impact, mathematical models of disease transmission have been studied to help understand disease dynamics and inform prevention strategies. Vaccination-one of the most important preventive measures of modern times-is of great interest both theoretically and empirically. And in contrast to traditional approaches, recent research increasingly explores the pivotal implications of individual behavior and heterogeneous contact patterns in populations. Our report reviews the developmental arc of theoretical epidemiology with emphasis on vaccination, as it led from classical models assuming homogeneously mixing (mean-field) populations and ignoring human behavior, to recent models that account for behavioral feedback and/or population spatial/social structure. Many of the methods used originated in statistical physics, such as lattice and network models, and their associated analytical frameworks. Similarly, the feedback loop between vaccinating behavior and disease propagation forms a coupled nonlinear system with analogs in physics. We also review the new paradigm of digital epidemiology, wherein sources of digital data such as online social media are mined for high-resolution information on epidemiologically relevant individual behavior. Armed with the tools and concepts of statistical physics, and further assisted by new sources of digital data, models that capture nonlinear interactions between behavior and disease dynamics offer a novel way of modeling real-world phenomena, and can help improve health outcomes. We conclude the review by discussing open problems in the field and promising directions for future research.

Analysis of Chromosomal Aberrations in the Blood Lymphocytes of Astronauts after Space Flight

NASA Technical Reports Server (NTRS)

George, K.; Kim, M. Y.; Elliott, T.; Cucinotta, F. A.

2007-01-01

It is a NASA requirement that biodosimetry analysis be performed on all US astronauts who participate in long duration missions of 3 months or more onboard the International Space Station. Cytogenetic analysis of blood lymphocytes is the most sensitive and reliable biodosimetry method available at present, especially if chromosome damage is assessed before as well as after space flight. Results provide a direct measurement of space radiation damage in vivo that takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. We present data obtained from all twenty-five of the crewmembers who have participated in the biodosimetry program so far. The yield of chromosome exchanges, measured using fluorescence in situ hybridization (FISH) technique with chromosome painting probes, increased after space flight for all these individuals. In vivo dose was derived from frequencies of chromosome exchanges using preflight calibration curves of in vitro exposed cells from the same individual, and RBE was compared with individually measured physically absorbed dose and projected organ dose equivalents. Biodosimetry estimates using samples collected within a few weeks of return from space lie within the range expected from physical dosimetry. For some of these individuals chromosome aberrations were assessed again several months after their respective missions and a temporal decline in stable exchanges was observed in some cases, suggesting that translocations are unstable with time after whole body exposure to space radiation. This may indicate complications with the use of translocations for retrospective dose reconstruction. Data from one crewmember who has participated in two separate long duration space missions and has been followed up for over 10 years provides limited data on the effect of repeat flights and shows a possible adaptive response to space radiation exposure.

The FERONIA Receptor Kinase Maintains Cell-Wall Integrity during Salt Stress through Ca2+ Signaling.

PubMed

Feng, Wei; Kita, Daniel; Peaucelle, Alexis; Cartwright, Heather N; Doan, Vinh; Duan, Qiaohong; Liu, Ming-Che; Maman, Jacob; Steinhorst, Leonie; Schmitz-Thom, Ina; Yvon, Robert; Kudla, Jörg; Wu, Hen-Ming; Cheung, Alice Y; Dinneny, José R

2018-03-05

Cells maintain integrity despite changes in their mechanical properties elicited during growth and environmental stress. How cells sense their physical state and compensate for cell-wall damage is poorly understood, particularly in plants. Here we report that FERONIA (FER), a plasma-membrane-localized receptor kinase from Arabidopsis, is necessary for the recovery of root growth after exposure to high salinity, a widespread soil stress. The extracellular domain of FER displays tandem regions of homology with malectin, an animal protein known to bind di-glucose in vitro and important for protein quality control in the endoplasmic reticulum. The presence of malectin-like domains in FER and related receptor kinases has led to widespread speculation that they interact with cell-wall polysaccharides and can potentially serve a wall-sensing function. Results reported here show that salinity causes softening of the cell wall and that FER is necessary to sense these defects. When this function is disrupted in the fer mutant, root cells explode dramatically during growth recovery. Similar defects are observed in the mur1 mutant, which disrupts pectin cross-linking. Furthermore, fer cell-wall integrity defects can be rescued by treatment with calcium and borate, which also facilitate pectin cross-linking. Sensing of these salinity-induced wall defects might therefore be a direct consequence of physical interaction between the extracellular domain of FER and pectin. FER-dependent signaling elicits cell-specific calcium transients that maintain cell-wall integrity during salt stress. These results reveal a novel extracellular toxicity of salinity, and identify FER as a sensor of damage to the pectin-associated wall. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

In situ mitigation of subsurface and peripheral focused ion beam damage via simultaneous pulsed laser heating

DOE PAGES

Stanford, Michael G.; Lewis, Brett B.; Iberi, Vighter O.; ...

2016-02-16

Focused helium and neon ion (He(+)/Ne(+) ) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+) /Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposuremore » process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. In conclusion, these results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via focused ion beams.« less

[Possibilities of medical opinionating in cases associated with "exposure to direct danger of death or serious health damage"].

PubMed

Konopka, Tomasz; Skupień, Elzbieta

2008-01-01

In the opinion of some forensic medicine experts, assessment of potential consequences in keeping with Article 160 of the Polish Penal code, which refers to the crime of "exposure to direct danger of death or severe health damage", lies within the competence of medicolegal specialists. This view is accepted by courts and prosecution offices. However, the knowledge of physicians in the field of predicting consequences which did not occur is only somewhat better than that of lawyers. In simple cases, e.g. in trauma involving a sensitive area of the body, passing an opinion confirming a serious danger is not associated with any major problems. Similarly, no problems arise when passing an opinion on the lack of such a danger e.g. in the case of traumawithout any injuries. In complex cases, however, which include the majority of medical error cases, passing an opinion on exposure to direct danger of death or severe health damage may be not feasible.

Break-induced telomere synthesis underlies alternative telomere maintenance

PubMed Central

Dilley, Robert L.; Verma, Priyanka; Cho, Nam Woo; Winters, Harrison D.; Wondisford, Anne R.; Greenberg, Roger A.

2017-01-01

Homology-directed DNA repair is essential for genome maintenance through templated DNA synthesis. Alternative lengthening of telomeres (ALT) necessitates homology-directed DNA repair to maintain telomeres in about 10–15% of human cancers. How DNA damage induces assembly and execution of a DNA replication complex (break-induced replisome) at telomeres or elsewhere in the mammalian genome is poorly understood. Here we define break-induced telomere synthesis and demonstrate that it utilizes a specialized replisome, which underlies ALT telomere maintenance. DNA double-strand breaks enact nascent telomere synthesis by long-tract unidirectional replication. Proliferating cell nuclear antigen (PCNA) loading by replication factor C (RFC) acts as the initial sensor of telomere damage to establish predominance of DNA polymerase δ (Pol δ) through its POLD3 subunit. Break-induced telomere synthesis requires the RFC–PCNA–Pol δ axis, but is independent of other canonical replisome components, ATM and ATR, or the homologous recombination protein Rad51. Thus, the inception of telomere damage recognition by the break-induced replisome orchestrates homology-directed telomere maintenance. PMID:27760120

Orthogonal cutting modeling of hybrid CFRP/Ti toward specific cutting energy and induced damage analyses

NASA Astrophysics Data System (ADS)

Xu, Jinyang; El Mansori, Mohamed

2016-10-01

This paper studied the machinability of hybrid CFRP/Ti stack via the numerical approach. To this aim, an original FE model consisting of three fundamental physical constituents, i.e., CFRP phase, interface and Ti phase, was established in the Abaqus Explicit/code to construct the machining behavior of the composite-to-metal alliance. The CFRP phase was modeled as an equivalent homogeneous material (EHM) by considering its anisotropic behavior relative to the fiber orientation (θ) while the Ti alloy phase was assumed to exhibit isotropic and elastic-plastic behavior. The "interface" linking the "CFRP-to-Ti" contact boundary was physically modeled as an intermediate transition region through the concept of cohesive zone (CZ). Different constitutive laws and damage criteria were implemented to simulate the chip separation process of the bi-material system. The key cutting responses including specific cutting energy consumption, induced subsurface damage, and interface delamination were precisely addressed via the comprehensive FE analyses, and several key conclusions were drawn from this study.