Is Thrombocytopenia an Early Prognostic Marker in Septic Shock?

PubMed

Thiery-Antier, Nadiejda; Binquet, Christine; Vinault, Sandrine; Meziani, Ferhat; Boisramé-Helms, Julie; Quenot, Jean-Pierre

2016-04-01

To assess whether early thrombocytopenia during septic shock is associated with an increased risk of death at day 28 and to identify risk factors associated with a low platelet count. Prospective, multicenter, observational cohort study. Fourteen ICUs from 10 French university teaching and nonacademic hospitals. Consecutive adult patients with septic shock admitted between November 2009 and September 2011 were eligible. None. Of the 1,495 eligible patients, 1,486 (99.4%) were included. Simplified Acute Physiology Score II score of greater than or equal to 56, immunosuppression, age of more than 65 years, cirrhosis, bacteremia (p ≤ 0.001 for each), and urinary sepsis (p = 0.005) were globally associated with an increased risk of thrombocytopenia within the first 24 hours following the onset of septic shock. Survival at day 28 estimated by the Kaplan-Meier method was lower in patients with thrombocytopenia and decreased with thrombocytopenia severity. By multivariate Cox regression, a platelet count of less than or equal to 100,000/mm3 was independently associated with a significantly increased risk of death within the 28 days following septic shock onset. The risk of death increased with the severity of thrombocytopenia (hazard ratio, 1.65; 95% CI, 1.31-2.08 for a platelet count below 50,000/mm3 vs > 150,000/mm3; p < 0.0001). This is the first study to investigate thrombocytopenia within the first 24 hours of septic shock onset as a prognostic marker of survival at day 28 in a large cohort of ICU patients. Measuring platelet count is inexpensive and easily feasible for the physician in routine practice, and thus, it could represent an easy "alert system" among patients in septic shock.

Early administration of hydrocortisone replacement after the advent of septic shock: impact on survival and immune response*.

PubMed

Katsenos, Chrysostomos S; Antonopoulou, Anastasia N; Apostolidou, Efterpi N; Ioakeimidou, Aikaterini; Kalpakou, Georgia Th; Papanikolaou, Metaxia N; Pistiki, Aikaterini C; Mpalla, Margarita C; Paraschos, Michael D; Patrani, Maria A; Pratikaki, Maria E; Retsas, Theodoros A; Savva, Athina A; Vassiliagkou, Spyridoula D; Lekkou, Alexandra A; Dimopoulou, Ioanna; Routsi, Christina; Mandragos, Konstantinos E

2014-07-01

To investigate the impact of early initiation of hydrocortisone therapy on the clinical course of septic shock and on cytokine release. Prospective study in patients with septic shock treated with low doses of hydrocortisone. ICUs and general wards. Over a 2-year period, 170 patients with septic shock treated with low doses of hydrocortisone were enrolled. Blood was sampled from 34 patients for isolation of peripheral blood mononuclear cells and cytokine stimulation before and 24 hours after the start of hydrocortisone. None. After quartile analysis, patients were divided into those with early initiation of hydrocortisone (< 9 hr after vasopressors, n = 46) and those with late initiation of hydrocortisone (> 9 hr after vasopressors, n = 124). After adjusting for disease severity and type of infection, a protective effect of early hydrocortisone administration against unfavorable outcome was found (hazard ratio, 0.20; p = 0.012). Time of discontinuation of vasopressors was earlier among patients with initiation of hydrocortisone within 9 hours. Production of tumor necrosis factor-α was lower among patients who had had hydrocortisone early. In patients receiving hydrocortisone for septic shock, early initiation of treatment was associated with improved survival. This treatment was also associated with attenuated stimulation of tumor necrosis factor-α.

Renal Blood Flow, Glomerular Filtration Rate, and Renal Oxygenation in Early Clinical Septic Shock.

PubMed

Skytte Larsson, Jenny; Krumbholz, Vitus; Enskog, Anders; Bragadottir, Gudrun; Redfors, Bengt; Ricksten, Sven-Erik

2018-06-01

Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. Prospective comparative study. General and cardiothoracic ICUs. Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58). None. Data on systemic hemodynamics and renal variables were obtained during two 30-minute periods. Renal blood flow was measured by the infusion clearance of para-aminohippuric acid, corrected for renal extraction of para-aminohippuric acid. Renal filtration fraction was measured by renal extraction of chromium-51 labeled EDTA. Renal oxygenation was estimated from renal oxygen extraction. Renal oxygen delivery (-24%; p = 0.037) and the renal blood flow-to-cardiac index ratio (-21%; p = 0.018) were lower, renal vascular resistance was higher (26%; p = 0.027), whereas renal blood flow tended to be lower (-19%; p = 0.068) in the septic group. Glomerular filtration rate (-32%; p = 0.006) and renal sodium reabsorption (-29%; p = 0.014) were both lower in the septic group. Neither renal filtration fraction nor renal oxygen consumption differed significantly between groups. Renal oxygen extraction was significantly higher in the septic group (28%; p = 0.022). In the septic group, markers of tubular injury were elevated. In early clinical septic shock, renal function was lower, which was accompanied by renal vasoconstriction, a lower renal oxygen delivery, impaired renal oxygenation, and tubular sodium reabsorption at a high oxygen cost compared with controls.

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior.

PubMed

Lipscomb, Shannon T; Laurent, Heidemarie; Neiderhiser, Jenae M; Shaw, Daniel S; Natsuaki, Misaki N; Reiss, David; Leve, Leslie D

2014-01-01

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children.

A Search for Early High-Energy Afterglows in BATSE Gamma-Ray Bursts

NASA Technical Reports Server (NTRS)

Giblin, Timothy W.

2003-01-01

The scope of this project was to perform a detailed search for the early high-energy afterglow component of gamma-ray bursts (GRBs) in the BATSE GRB data archive. GRBs are believed to be the product of shock waves generated in a relativistic outflow from the demise of extremely massive stars and/or binary neutron star mergers. The outflow undeniably encounters the ambient medium of the progenitor object and another shock wave is set up. A forward shock propagates into the medium and a reverse shock propagates through the ejecta. This "external" shock dissipates the kinetic energy of the ejecta in the form of radiation via synchrotron losses and slows the outflow eventually to a non-relativistic state. Radiation from the forward external shock is therefore expected to be long-lived, lasting days, weeks, and even months. This radiation is referred to as the 'afterglow'.

Lactate clearance cut off for early mortality prediction in adult sepsis and septic shock patients

NASA Astrophysics Data System (ADS)

Sinto, R.; Widodo, D.; Pohan, H. T.

2018-03-01

Previous lactate clearance cut off for early mortality prediction in sepsis and septic shock patient was determined by consensus from small sample size-study. We investigated the best lactate clearance cut off and its ability to predict early mortality in sepsis and septic shock patients. This cohort study was conducted in Intensive Care Unit of CiptoMangunkusumo Hospital in 2013. Patients’ lactate clearance and eight other resuscitationendpoints were recorded, and theoutcome was observed during the first 120 hours. The clearance cut off was determined using receiver operating characteristic (ROC) analysis, and its ability was investigated with Cox’s proportional hazard regression analysis using other resuscitation endpoints as confounders. Total of 268 subjects was included, of whom 70 (26.11%) subjects died within the first 120 hours. The area under ROC of lactate clearance to predict early mortality was 0.78 (95% % confidence interval [CI] 0.71-0.84) with best cut off was <7.5% (sensitivity and specificity 88.99% and 81.4% respectively). Compared with group achieving lactate clearance target, group not achieving lactate clearance target had to increase early mortality risk (adjusted hazard ratio 13.42; 95%CI 7.19-25.07). In conclusion, the best lactate clearance cut off as anearly mortality predictor in sepsis and septic shock patients is 7.5%.

Genetic vulnerability interacts with parenting and early care education to predict increasing externalizing behavior

PubMed Central

Lipscomb, Shannon T.; Laurent, Heidemarie; Neiderhiser, Jenae M.; Shaw, Daniel S.; Natsuaki, Misaki N.; Reiss, David; Leve, Leslie D.

2014-01-01

The current study examined interactions among genetic influences and children’s early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental regulation. Early environments included both family (overreactive parenting) and out-of-home factors (center-based Early Care and Education; ECE). Overreactive parenting predicted more child externalizing behaviors. Attending center-based ECE was associated with increasing externalizing behaviors only for children with genetic liability for dysregulation. Additionally, children who were at risk for externalizing behaviors due to both genetic variability and exposure to center-based ECE were more sensitive to the effects of overreactive parenting on externalizing behavior than other children. PMID:25067867

Early initiation of low-dose hydrocortisone treatment for septic shock in adults: A randomized clinical trial.

PubMed

Lv, Qing-Quan; Gu, Xiao-Hua; Chen, Qi-Hong; Yu, Jiang-Quan; Zheng, Rui-Qiang

2017-12-01

Physiologic dose hydrocortisone is part of the suggested adjuvant therapies for patients with septic shock. However, the association between the corticosteroid therapy and mortality in patients with septic shock is still not clear. Some authors considered that the mortality is related to the time frame between development of septic shock and start of low dose hydrocortisone. Thus we designed a placebo-controlled, randomized clinical trial to assess the importance of early initiation of low dose hydrocortisone for the final outcome. A total of 118 patients with septic shock were recruited in the study. All eligible patients were randomized to receive hydrocortisone (n=58) or normal saline (n=60). The study medication (hydrocortisone and normal saline) was initiated simultaneously with vasopressors. The primary end-point was 28-day mortality. The secondary end-points were the reversal of shock, in-hospital mortality and the duration of ICU and hospital stay. The proportion of patients with reversal of shock was similar in the two groups (P=0.602); There were no significant differences in 28-day or hospital all-cause mortality; length of stay in the ICU or hospital between patients treated with hydrocortisone or normal saline. The early initiation of low-dose of hydrocortisone did not decrease the risk of mortality, and the length of stay in the ICU or hospital in adults with septic shock. www.clinicaltrials.govNCT02580240. Copyright © 2017 Elsevier Inc. All rights reserved.

Women's experiences of participating in the early external cephalic version 2 trial.

PubMed

Murray-Davis, Beth; Marion, Anya; Malott, Anne; Reitsma, Angela; Hutton, Eileen K

2012-03-01

The international, multicenter External Cephalic Version 2 (ECV2) Trial compared early external cephalic version at 34(0/7) to 35(6/7) weeks with that at greater than 37 weeks. A total of 1,543 women were randomized from 68 centers in 21 countries. The goal of this component of the trial was to understand women's views about participation in a research trial and timing of external cephalic version. A postpartum questionnaire was completed containing a 5-point Likert scale examining contact and availability of staff, choice of timing of external cephalic version, preference of randomization, convenience of participating, and overall satisfaction. Participants also completed two open-ended questions related to timing of external cephalic version and satisfaction with the trial. Descriptive statistics and content analysis were used to analyze data. A total of 1,458 women completed the questionnaire, of whom 86 percent said "yes"-they would participate in the trial again. Themes influencing decisions about participating were perceptions of the external cephalic version experience, preferred mode of delivery, preferred timing of external cephalic version, and perceptions of the effectiveness of external cephalic version and of the trial environment. Many participants preferred the early timing of the procedure offered through the trial because of perceived advantages of a smaller baby being easier to turn and the opportunity for repeat procedures. Women were positive about their participation in the trial. Early external cephalic version was preferred over the traditional timing as it was perceived to afford both physiologic and practical advantages. © 2012, Copyright the Authors. Journal compilation © 2012, Wiley Periodicals, Inc.

Early parenting, represented family relationships, and externalizing behavior problems in children born preterm.

PubMed

Poehlmann, Julie; Burnson, Cynthia; Weymouth, Lindsay A

2014-01-01

Through assessment of 173 preterm infants and their mothers at hospital discharge and at 9, 16, 24, 36, and 72 months, the study examined early parenting, attachment security, effortful control, and children's representations of family relationships in relation to subsequent externalizing behavior problems. Less intrusive early parenting predicted more secure attachment, better effortful control skills, and fewer early behavior problems, although it did not directly relate to the structural or content characteristics of children's represented family relationships. Children with higher effortful control scores at 24 months had more coherent family representations at 36 months. Moreover, children who exhibited less avoidance in their family representations at 36 months had fewer mother-reported externalizing behavior problems at 72 months. The study suggests that early parenting quality and avoidance in children's represented relationships are important for the development of externalizing behavior problems in children born preterm.

Externalizing behavior from early childhood to adolescence: Prediction from inhibition, language, parenting, and attachment.

PubMed

Roskam, Isabelle

2018-03-22

The aim of the current research was to disentangle four theoretically sound models of externalizing behavior etiology (i.e., attachment, language, inhibition, and parenting) by testing their relation with behavioral trajectories from early childhood to adolescence. The aim was achieved through a 10-year prospective longitudinal study conducted over five waves with 111 referred children aged 3 to 5 years at the onset of the study. Clinical referral was primarily based on externalizing behavior. A multimethod (questionnaires, testing, and observations) approach was used to estimate the four predictors in early childhood. In line with previous studies, the results show a significant decrease of externalizing behavior from early childhood to adolescence. The decline was negatively related to mothers' coercive parenting and positively related to attachment security in early childhood, but not related to inhibition and language. The study has implications for research into externalizing behavior etiology recommending to gather hypotheses from various theoretically sound models to put them into competition with one another. The study also has implications for clinical practice by providing clear indications for prevention and early intervention.

Early Parenting, Represented Family Relationships, and Externalizing Behavior Problems in Children Born Preterm

PubMed Central

Poehlmann, Julie; Burnson, Cynthia; Weymouth, Lindsay A.

2015-01-01

Through assessment of 173 preterm infants and their mothers at hospital discharge and at 9, 16, 24, 36, and 72 months, the study examined early parenting, attachment security, effortful control, and children’s representations of family relationships in relation to subsequent externalizing behavior problems. Less intrusive early parenting predicted more secure attachment, better effortful control skills, and fewer early behavior problems, although it did not directly relate to the structural or content characteristics of children’s represented family relationships. Children with higher effortful control scores at 24 months had more coherent family representations at 36 months. Moreover, children who exhibited less avoidance in their family representations at 36 months had fewer mother-reported externalizing behavior problems at 72 months. The study suggests that early parenting quality and avoidance in children’s represented relationships are important for the development of externalizing behavior problems in children born preterm. PMID:24580068

Trial of early, goal-directed resuscitation for septic shock.

PubMed

Mouncey, Paul R; Osborn, Tiffany M; Power, G Sarah; Harrison, David A; Sadique, M Zia; Grieve, Richard D; Jahan, Rahi; Harvey, Sheila E; Bell, Derek; Bion, Julian F; Coats, Timothy J; Singer, Mervyn; Young, J Duncan; Rowan, Kathryn M

2015-04-02

Early, goal-directed therapy (EGDT) is recommended in international guidelines for the resuscitation of patients presenting with early septic shock. However, adoption has been limited, and uncertainty about its effectiveness remains. We conducted a pragmatic randomized trial with an integrated cost-effectiveness analysis in 56 hospitals in England. Patients were randomly assigned to receive either EGDT (a 6-hour resuscitation protocol) or usual care. The primary clinical outcome was all-cause mortality at 90 days. We enrolled 1260 patients, with 630 assigned to EGDT and 630 to usual care. By 90 days, 184 of 623 patients (29.5%) in the EGDT group and 181 of 620 patients (29.2%) in the usual-care group had died (relative risk in the EGDT group, 1.01; 95% confidence interval [CI], 0.85 to 1.20; P=0.90), for an absolute risk reduction in the EGDT group of -0.3 percentage points (95% CI, -5.4 to 4.7). Increased treatment intensity in the EGDT group was indicated by increased use of intravenous fluids, vasoactive drugs, and red-cell transfusions and reflected by significantly worse organ-failure scores, more days receiving advanced cardiovascular support, and longer stays in the intensive care unit. There were no significant differences in any other secondary outcomes, including health-related quality of life, or in rates of serious adverse events. On average, EGDT increased costs, and the probability that it was cost-effective was below 20%. In patients with septic shock who were identified early and received intravenous antibiotics and adequate fluid resuscitation, hemodynamic management according to a strict EGDT protocol did not lead to an improvement in outcome. (Funded by the United Kingdom National Institute for Health Research Health Technology Assessment Programme; ProMISe Current Controlled Trials number, ISRCTN36307479.).

Peer rejection in childhood, involvement with antisocial peers in early adolescence, and the development of externalizing behavior problems

PubMed Central

Laird, Robert D.; Jordan, Kristi Y.; Dodge, Kenneth A.; Pettit, Gregory S.; Bates, John E.

2009-01-01

A longitudinal, prospective design was used to examine the roles of peer rejection in middle childhood and antisocial peer involvement in early adolescence in the development of adolescent externalizing behavior problems. Both early starter and late starter pathways were considered. Classroom sociometric interviews from ages 6 through 9 years, adolescent reports of peers' behavior at age 13 years, and parent, teacher, and adolescent self-reports of externalizing behavior problems from age 5 through 14 years were available for 400 adolescents. Results indicate that experiencing peer rejection in elementary school and greater involvement with antisocial peers in early adolescence are correlated but that these peer relationship experiences may represent two different pathways to adolescent externalizing behavior problems. Peer rejection experiences, but not involvement with antisocial peers, predict later externalizing behavior problems when controlling for stability in externalizing behavior. Externalizing problems were most common when rejection was experienced repeatedly. Early externalizing problems did not appear to moderate the relation between peer rejection and later problem behavior. Discussion highlights multiple pathways connecting externalizing behavior problems from early childhood through adolescence with peer relationship experiences in middle childhood and early adolescence. PMID:11393650

The Association of Birth Complications and Externalizing Behavior in Early Adolescents: Direct and Mediating Effects

PubMed Central

Liu, Jianghong; Raine, Adrian; Wuerker, Anne; Venables, Peter H.; Mednick, Sarnoff

2012-01-01

Prior studies have shown that birth complications interact with psychosocial risk factors in predisposing to increased externalizing behavior in childhood and criminal behavior in adulthood. However, little is known about the direct relationship between birth complications and externalizing behavior. Furthermore, the mechanism by which the birth complications predispose to externalizing behavior is not well explored. This study aims to assess whether birth complications predispose to early adolescent externalizing behavior and to test whether Intelligence Quotient (IQ) mediates relationships between predictor and outcome variables. We used data from a prospective, longitudinal birth cohort of 1,795 3-year-old boys and girls from Mauritius to test hypotheses. Birth complications were assessed from hospital record data, malnutrition from a pediatric exam at age 3 years, psychosocial adversity from parental interviews at age 3 years, and externalizing behavior problems from parental ratings at age 11 years. We found that babies with birth complications are more likely to develop externalizing behavior problems at age 11. Low IQ was associated with birth complications and was found to mediate the link between early predictors and later externalizing behavior. These prospective, longitudinal findings have potential clinical implications for the identification of early adolescent externalizing behavior and for public health attempts to prevent the occurrence of child externalizing behavior problems. PMID:22485069

External-environmental and internal-health early life predictors of adolescent development.

PubMed

Hartman, Sarah; Li, Zhi; Nettle, Daniel; Belsky, Jay

2017-12-01

A wealth of evidence documents associations between various aspects of the rearing environment and later development. Two evolutionary-inspired models advance explanations for why and how such early experiences shape later functioning: (a) the external-prediction model, which highlights the role of the early environment (e.g., parenting) in regulating children's development, and (b) the internal-prediction model, which emphasizes internal state (i.e., health) as the critical regulator. Thus, by using data from the NICHD Study of Early Child Care and Youth Development, the current project draws from both models by investigating whether the effect of the early environment on later adolescent functioning is subject to an indirect effect by internal-health variables. Results showed a significant indirect effect of internal health on the relation between the early environment and adolescent behavior. Specifically, early environmental adversity during the first 5 years of life predicted lower quality health during childhood, which then led to problematic adolescent functioning and earlier age of menarche for girls. In addition, for girls, early adversity predicted lower quality health that forecasted earlier age of menarche leading to increased adolescent risk taking. The discussion highlights the importance of integrating both internal and external models to further understand the developmental processes that effect adolescent behavior.

Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Difference in Externalizing Behavior as a Mediator

PubMed Central

Min, Meeyoung O.; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T.

2015-01-01

Background Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Methods Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year old adolescents participated in a prospective longitudinal study. Adolescents’ sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Results Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI= 1.2 – 4.1, p < .01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4 – 4.7, p < .002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. Conclusions PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. PMID:26088698

Effects of prenatal cocaine exposure on early sexual behavior: Gender difference in externalizing behavior as a mediator.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T

2015-08-01

Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year-old adolescents participated in a prospective longitudinal study. Adolescents' sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI=1.2-4.1, p<.01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4-4.7, p<.002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Internal and external axial corner flows

NASA Technical Reports Server (NTRS)

Kutler, P.; Shankar, V.; Anderson, D. A.; Sorenson, R. L.

1975-01-01

The inviscid, internal, and external axial corner flows generated by two intersecting wedges traveling supersonically are obtained by use of a second-order shock-capturing, finite-difference approach. The governing equations are solved iteratively in conical coordinates to yield the complicated wave structure of the internal corner and the simple peripheral shock of the external corner. The numerical results for the internal flows compare favorably with existing experimental data.

5HTTLPR genotype moderates the longitudinal impact of early caregiving on externalizing behavior

PubMed Central

Smyke, Anna T.; Gleason, Mary Margaret; Nelson, Charles A.; Zeanah, Charles H.; Fox, Nathan A; Drury, Stacy S.

2014-01-01

We examined caregiver report of externalizing behavior from 12 to 54 months of age in 102 children randomized to care as usual in institutions or to newly-created high quality foster care. At baseline no differences by group or genotype in externalizing were found. However, changes in externalizing from baseline to 42 months of age were moderated by 5HTTLPR genotype and intervention group, where the slope for s/s individuals differed as a function of intervention group. The slope for individuals carrying the l allele did not significantly differ between groups. At 54 months of age, s/s children in the foster care group had the lowest levels of externalizing behavior, while children with the s/s genotype in the care as usual group demonstrated the highest rates of externalizing behavior. No intervention group differences were found in externalizing behavior among children who carried the l allele. These findings, within a randomized control trial of foster care compared to continued care as usual, indicate that 5HTTLPR genotype moderates the relation between early caregiving environments to predict externalizing behavior in children exposed to early institutional care in a manner most consistent with differential susceptibility. PMID:25640827

Probing the early stages of shock-induced chondritic meteorite formation at the mesoscale

PubMed Central

Rutherford, Michael E.; Chapman, David J.; Derrick, James G.; Patten, Jack R. W.; Bland, Philip A.; Rack, Alexander; Collins, Gareth S.; Eakins, Daniel E.

2017-01-01

Chondritic meteorites are fragments of asteroids, the building blocks of planets, that retain a record of primordial processes. Important in their early evolution was impact-driven lithification, where a porous mixture of millimetre-scale chondrule inclusions and sub-micrometre dust was compacted into rock. In this Article, the shock compression of analogue precursor chondrite material was probed using state of the art dynamic X-ray radiography. Spatially-resolved shock and particle velocities, and shock front thicknesses were extracted directly from the radiographs, representing a greatly enhanced scope of data than could be measured in surface-based studies. A statistical interpretation of the measured velocities showed that mean values were in good agreement with those predicted using continuum-level modelling and mixture theory. However, the distribution and evolution of wave velocities and wavefront thicknesses were observed to be intimately linked to the mesoscopic structure of the sample. This Article provides the first detailed experimental insight into the distribution of extreme states within a shocked powder mixture, and represents the first mesoscopic validation of leading theories concerning the variation in extreme pressure-temperature states during the formation of primordial planetary bodies. PMID:28555619

Density Shock Waves in Confined Microswimmers

NASA Astrophysics Data System (ADS)

Tsang, Alan Cheng Hou; Kanso, Eva

2016-01-01

Motile and driven particles confined in microfluidic channels exhibit interesting emergent behavior, from propagating density bands to density shock waves. A deeper understanding of the physical mechanisms responsible for these emergent structures is relevant to a number of physical and biomedical applications. Here, we study the formation of density shock waves in the context of an idealized model of microswimmers confined in a narrow channel and subject to a uniform external flow. Interestingly, these density shock waves exhibit a transition from "subsonic" with compression at the back to "supersonic" with compression at the front of the population as the intensity of the external flow increases. This behavior is the result of a nontrivial interplay between hydrodynamic interactions and geometric confinement, and it is confirmed by a novel quasilinear wave model that properly captures the dependence of the shock formation on the external flow. These findings can be used to guide the development of novel mechanisms for controlling the emergent density distribution and the average population speed, with potentially profound implications on various processes in industry and biotechnology, such as the transport and sorting of cells in flow channels.

The Cost Implications in Ontario, Alberta, and British Columbia of Early Versus Delayed External Cephalic Version in the Early External Cephalic Version 2 (EECV2) Trial.

PubMed

Ahmed, Rashid J; Gafni, Amiram; Hutton, Eileen K

2016-03-01

According to the Early External Cephalic Version (EECV2) Trial, planning external cephalic version (ECV) early in pregnancy results in fewer breech presentations at delivery compared with delayed external cephalic version. A Cochrane review conducted after the EECV2 Trial identified an increase in preterm birth associated with early ECV. We examined whether a policy of routine early ECV (i.e., before 37 weeks' gestation) is more or less costly than a policy of delayed ECV. We undertook this analysis from the perspective of a third-party payer (Ministry of Health). We applied data, using resources reported in the EECV2 Trial, to the Canadian context using 10 hospital unit costs and 17 physician service/procedure unit costs. The data were derived from the provincial health insurance plan schedule of medical benefits in three Canadian provinces (Ontario, Alberta, and British Columbia). The difference in mean total costs between study groups was tested for each province separately. We found that planning early ECV results in higher costs than planning delayed ECV. The mean costs of all physician services/procedures and hospital units for planned ECV compared with delayed ECV were $7997.32 versus $7263.04 in Ontario (P < 0.001), $8162.82 versus $7410.55 in Alberta (P < 0.001), and $8178.92 versus $7417.04 in British Columbia (P < 0.001), respectively. From the perspective of overall cost, our analyses do not support a policy of routinely planning ECV before 37 weeks' gestation. Copyright © 2016 The Society of Obstetricians and Gynaecologists of Canada/La Société des obstétriciens et gynécologues du Canada. Published by Elsevier Inc. All rights reserved.

[Phaeochromocytoma as an unusual aetiology of cardiogenic shock].

PubMed

Ouchikhe, A; Lehoux, P; Gringore, A; Renouf, P; Deredec, R; Tasle, M; Massetti, M; Khayat, A; Saloux, E; Grollier, G; Samama, G; Gérard, J-L

2006-01-01

The authors reported a case involving a young patient with a cardiogenic shock associated to an acute pulmonary oedema. According to the seriousness of the shock, an external ventricular assist device (VAD) was initially inserted and replaced thereafter because of the cardiovascular instability, by an external pneumatic biventricular assist device. A cardiogenic shock induced by an acute adrenergic myocarditis due to a phaeochromocytoma was diagnosed. The patient was weaned from the VAD on day 84 and was scheduled for elective surgery of the phaeochromocytoma on day 93. The authors discussed the time of the surgery according to the anticoagulation therapy necessary to the VAD and the necessary caution taken if a cardiogenic shock appeared around surgery.

δ opioid receptor antagonist, ICI 174,864, is suitable for the early treatment of uncontrolled hemorrhagic shock in rats.

PubMed

Liu, Liangming; Tian, Kunlun; Zhu, Yu; Ding, Xiaoli; Li, Tao

2013-08-01

Fluid resuscitation is the essential step for early treatment of traumatic hemorrhagic shock. However, its implementation is greatly limited before hospital or during evacuation. The authors investigated whether δ opioid receptor antagonist ICI 174,864 was suitable for the early treatment of traumatic hemorrhagic shock. With uncontrolled hemorrhagic-shock rats, the antishock effects of six dosages of ICI 174,864 (0.1, 0.3, 0.5, 1, 3, and 5 mg/kg) infused with or without a small volume of lactated Ringer's solution (LR) before bleeding controlled or bleeding cessation at different times were observed. ICI 174,864 (0.1-3 mg/kg) with or without 1/4 volume of LR infusion showed dose-dependent increase in the mean arterial blood pressure, and significantly prolonged the survival time and 8-h survival rate, as compared with ICI 174,864 plus 1/2 volume of LR infusion. The best effect was shown with 3 mg/kg of ICI 174,864. Bleeding cessation at 1, 2, or 3 h during infusion of ICI 174,864 (3 mg/kg) plus 1/4 volume of LR improved subsequent treatment (70% 24-h survival rate vs. 50 and 10% 24-h survival rate in hypotensive resuscitation and LR group, respectively). There was significant improvement in hemodynamic parameters, oxygen delivery, and tissue perfusion of hemorrhagic-shock rats with 3 mg/kg of ICI 174,864 plus 1/4 volume of LR infusion. δ Opioid receptor antagonist ICI 174,864 alone or with small volume of fluid infusion has good beneficial effect on uncontrolled hemorrhagic shock. Its early application can "buy" time for subsequent treatment of traumatic shock.

Early Treatment in Shock

DTIC Science & Technology

2011-06-01

mem -6 branes releasing RNA into the lysis solution, and shears the genomic DNA decreasing 7 the viscosity of the lysate. Whole blood lysates from...doses, compared with saline controls. The L-arginine groups 3 showed increased OHP and wound breaking strength as compared with both shocked 4 and

A Prospective Randomized Controlled Trial of the Efficacy of External Physical Vibration Lithecbole after Extracorporeal Shock Wave Lithotripsy for a Lower Pole Renal Stone Less Than 2 cm.

PubMed

Long, Qilai; Zhang, Jian; Xu, Zhibing; Zhu, Yanjun; Liu, Li; Wang, Hang; Guo, Jianming; Wang, Guomin

2016-04-01

We evaluate the efficacy and safety of external physical vibration lithecbole in improving the clearance rates of lower pole renal stones after shock wave lithotripsy. A total of 71 patients with lower pole renal stones (6 to 20 mm) were prospectively randomized into 2 groups. In the treatment group 34 patients were treated with external physical vibration lithecbole after shock wave lithotripsy. In the control group 37 patients underwent shock wave lithotripsy only. External physical vibration lithecbole was performed without anesthesia by the same team using the Friend-I External Physical Vibration Lithecbole (Fu Jian Da Medical Instrument Co., Ltd, Zhengzhou, China). The stone-free rate, stone expulsion rate, stone expulsion time and incidence of complications were monitored. External physical vibration lithecbole was successful in assisting the discharge of stone fragments. The stone-free status was 76.5% in the treatment group and 48.6% in the control group (p=0.008). Stone expulsion rates at day 1, week 1 and week 3 were 76.5% (26), 94.1% (32) and 94.1% (32) in the treatment group vs 43.2% (16), 73.0% (27) and 89.2% (33) in the control group, respectively. Mean stone fragment expulsion time was 11.2 minutes in the treatment group and 9.17 hours in the control group (p=0.016). There was no significant difference in complications between the 2 groups (p >0.05). External physical vibration lithecbole was efficacious in assisting the discharge of lower pole renal stone fragments and can be used as an adjunctive method of minimally invasive stone treatment. However, additional investigations are needed to confirm the efficacy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

A systematic description of shocks in gamma-ray bursts - I. Formulation

NASA Astrophysics Data System (ADS)

Ziaeepour, Houri

2009-07-01

Since the suggestion of relativistic shocks as the origin of gamma-ray bursts (GRBs) in the early 1990s, the mathematical formulation of this process has stayed at a phenomenological level. One of the reasons for the slow development of theoretical works has been the simple power-law behaviour of the afterglows hours or days after the prompt gamma-ray emission. It was believed that they could be explained with these formulations. Nowadays, with the launch of the Swift satellite and implementation of robotic ground follow-ups, GRBs and their afterglow can be observed at multi-wavelengths from a few tens of seconds after trigger onwards. These observations have led to the discovery of features unexplainable by the simple formulation of the shocks and emission processes used up to now. Some of these features can be inherent in the nature and activities of the GRBs' central engines which are not yet well understood. On the other hand, the devil is in the detail and others may be explained with a more detailed formulation of these phenomena and without ad hoc addition of new processes. Such a formulation is the goal of this work. We present a consistent formulation of the kinematics and dynamics of the collision between two spherical relativistic shells, their energy dissipation and their coalescence. It can be applied to both internal and external shocks. Notably, we propose two phenomenological models for the evolution of the emitting region during the collision. One of these models is more suitable for the prompt/internal shocks and late external shocks, and the other for the afterglow/external collisions as well as the onset of internal shocks. We calculate a number of observables such as flux, lag between energy bands and hardness ratios. One of our aims has been a formulation complex enough to include the essential processes, but simple enough such that the data can be directly compared with the theory to extract the value and evolution of physical quantities. To

Quasi One-Dimensional Unsteady Modeling of External Compression Supersonic Inlets

NASA Technical Reports Server (NTRS)

Kopasakis, George; Connolly, Joseph W.; Kratz, Jonathan

2012-01-01

The AeroServoElasticity task under the NASA Supersonics Project is developing dynamic models of the propulsion system and the vehicle in order to conduct research for integrated vehicle dynamic performance. As part of this effort, a nonlinear quasi 1-dimensional model of an axisymmetric external compression supersonic inlet is being developed. The model utilizes compressible flow computational fluid dynamics to model the internal inlet segment as well as the external inlet portion between the cowl lip and normal shock, and compressible flow relations with flow propagation delay to model the oblique shocks upstream of the normal shock. The external compression portion between the cowl-lip and the normal shock is also modeled with leaking fluxes crossing the sonic boundary, with a moving CFD domain at the normal shock boundary. This model has been verified in steady state against tunnel inlet test data and it s a first attempt towards developing a more comprehensive model for inlet dynamics.

Effectiveness of Lower Energy Density Extracorporeal Shock Wave Therapy in the Early Stage of Avascular Necrosis of the Femoral Head.

PubMed

Han, Yong; Lee, June-Kyung; Lee, Bong-Yeon; Kee, Hoi-Sung; Jung, Kwang-Ik; Yoon, Seo-Ra

2016-10-01

To evaluate the effectiveness of lower energy flux density (EFD) extracorporeal shock wave therapy (ESWT) in the early stage of avascular necrosis (AVN) of the femoral head. Nineteen patients and 30 hips were enrolled. All subjects received 4 weekly sessions of ESWT, at different energy levels; group A (n=15; 1,000 shocks/session, EFD per shock 0.12 mJ/mm 2 ) and group B (n=15; 1,000 shocks/session, EFD per shock 0.32 mJ/mm 2 ). We measured pain by using the visual analog scale (VAS), and disability by using the Harris hip score, Hip dysfunction and Osteoarthritis Outcome Score (HOOS), and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). To determine the effect of the lower EFD ESWT, we assessed the VAS, Harris hip score, HOOS, WOMAC of the subjects before and at 1, 3, and 6 months. In both groups, the VAS, Harris hip score, HOOS, and WOMAC scores improved over time (p<0.05). Lower EFD ESWT may be an effective method to improve the function and to relieve pain in the early stage of AVN.

Internalizing and externalizing psychopathology as predictors of cannabis use disorder onset during adolescence and early adulthood.

PubMed

Farmer, Richard F; Seeley, John R; Kosty, Derek B; Gau, Jeff M; Duncan, Susan C; Lynskey, Michael T; Lewinsohn, Peter M

2015-09-01

Risk-related liabilities associated with the development of cannabis use disorders (CUDs) during adolescence and early adulthood are thought to be established well before the emergence of the index episode. In this study, internalizing and externalizing psychopathology from earlier developmental periods were evaluated as risk factors for CUDs during adolescence and early adulthood. Participants (N = 816) completed 4 diagnostic assessments between the ages 16 and 30, during which current and past CUDs were assessed as well as a full range of psychiatric disorders associated with internalizing and externalizing psychopathology domains. In unadjusted and adjusted time-to-event analyses, externalizing but not internalizing psychopathology from proximal developmental periods predicted subsequent CUD onset. A large proportion of adolescent and early adult cases, however, did not manifest any externalizing or internalizing psychopathology during developmental periods before CUD onset. Findings are consistent with the emerging view that externalizing disorders from proximal developmental periods are robust risk factors for CUDs. Although the identification of externalizing liabilities may aid in the identification of individuals at risk for embarking on developmental pathways that culminate in CUDs, such liabilities are an incomplete indication of overall risk. (c) 2015 APA, all rights reserved).

Early Differentiation of Kawasaki Disease Shock Syndrome and Toxic Shock Syndrome in a Pediatric Intensive Care Unit.

PubMed

Lin, Ying-Jui; Cheng, Ming-Chou; Lo, Mao-Hung; Chien, Shao-Ju

2015-11-01

Kawasaki disease shock syndrome (KDSS) and toxic shock syndrome (TSS) can present as shock and fever with skin rash, but the management of these 2 groups of patients is different. This report proposes to help clinicians earlier distinguish these 2 diseases and expedite institution of appropriate therapy. We retrospectively reviewed the medical records of patients admitted to the pediatric intensive care unit with the diagnosis of KDSS or TSS from January 2000 through December 2010. Clinical, laboratory and echocardiographic data were collected for analysis of differences between them. Seventeen patients met the inclusion criteria of KDSS and 16 had a confirmed diagnosis of TSS. The mean age of the KDSS group was significantly younger than that of the TSS group (36.8 ± 41.1 vs. 113.3 ± 55.6 months, P < 0.001). Significantly lower hemoglobulin and age-adjusted hemoglobulin concentrations were noted in the KDSS group [Hb, age-adjusted Z score, -1.88 (range, -3.9 to 3.9) vs. 0.89 (range, -6.4 to 10.8), P = 0.006]. The median platelet count of the KDSS group was nearly twice that of the TSS group [312 × 10³ per μL (range, 116-518) vs. 184.5 × 10³ per μL (range: 31-629), P = 0.021]. Echocardiographic abnormalities, such as valvulitis (mitral or tricuspid regurgitation) and coronary artery lesions, were significantly more common in the KDSS group (P = 0.022). Echocardiography, anemia and thrombocytosis are useful early differentiating features between KDSS and TSS patients.

Prospects for detection of very high-energy emission from GRB in the context of the external shock model

NASA Astrophysics Data System (ADS)

Galli, A.; Piro, L.

2008-10-01

Context: The detection of the 100 GeV-TeV emission by a gamma-ray burst (GRB) will provide an unprecedented opportunity to study the nature of the central engine and the interaction between the relativistic flow and the environment of the burst's progenitor. Aims: In this paper we show that there are exciting prospects of detecting from the burst by MAGIC high-energy (HE) emission during the early X-ray flaring activity and, later, during the normal afterglow phase. We also identify the best observational strategy: trigger conditions and time period of observation. Methods: We determine the expected HE emission from the flaring and afterglow phases of GRBs in the context of the external shock scenario and compare them with the MAGIC threshold. Results: We find that an X-ray flare with the average properties of the class can be detected in the 100 GeV range by MAGIC, provided that z ≲ 0.7. The requested observational window with MAGIC should then start from 10-20 s after the burst and cover about 1000-2000 s. Furthermore, we demonstrate that there are solid prospects of detecting the late afterglow emission in the same energy range for most of the bursts with z ≲ 0.5 if the density of the external medium is n ≳ a few cm-3. In this case, the MAGIC observation shall extend to about 10-20 ks. We provide recipes for tailoring this prediction to the observational properties of each burst, in particular the fluence in the prompt emission and the redshift, thus allowing an almost real time decision procedure to decide whether to continue the follow-up observation of a burst at late times.

Streptococcus agalactiae Toxic Shock-Like Syndrome

PubMed Central

Al Akhrass, Fadi; Abdallah, Lina; Berger, Steven; Hanna, Rami; Reynolds, Nina; Thompson, Shellie; Hallit, Rabih; Schlievert, Patrick M.

2013-01-01

Abstract We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome. PMID:23263717

Off-center blast in a shocked medium

NASA Astrophysics Data System (ADS)

Duncan-Miller, G. C.; Stone, W. D.

2018-07-01

When multiple blasts occur at different times, the situation arises in which a blast wave is propagating into a medium that has already been shocked. Determining the evolution in the shape of the second shock is not trivial, as it is propagating into air that is not only non-uniform, but also non-stationary. To accomplish this task, we employ the method of Kompaneets to determine the shape of a shock in a non-uniform media. We also draw from the work of Korycansky (Astrophys J 398:184-189. <ExternalRef> https://doi.org/10.1086/171847 ExternalRef>, 1992) on an off-center explosion in a medium with radially varying density. Extending this to treat non-stationary flow, and making use of approximations to the Sedov solution for the point blast problem, we are able to determine an analytic expression for the evolving shape of the second shock. In particular, we consider the case of a shock in air at standard ambient temperature and pressure, with the second shock occurring shortly after the original blast wave reaches it, as in a sympathetic detonation.

[Incidence and influencing factors of distal external iliac lymph node metastasis in early cervical cancer].

PubMed

Yin, Yueju; Sheng, Xiugui; Li, Xinglan; Li, Dapeng; Han, Xiaoyun; Zhang, Xiaoling; Zhang, Tingting

2014-06-01

The distal external iliac lymph nodes are located along the external iliac artery between the deep circumflex iliac vein and the inguinal canal. Our study aimed to investigate the incidence of metastasis in distal external iliac lymph nodes and its association with clinicopathological factors in patients with early stage cervical cancer, and to determine the role of distal external iliac lymph nodes dissection in the surgery. Five hundred and twenty-four patients with early stage cervical cancer underwent radical hysterectomy and bilateral pelvic lymphadenectomy in the Shandong Province Cancer Hospital between June 1995 and December 2011, and their clinicopathological features were analyzed retrospectively. Of the 524 patients, 124 (23.7%) had pelvic lymph node metastasis. The metastasis rates were 16.2% (85 of 524 patients) in the obturator lymph nodes, 12.2% (64 of 524 patients) in the internal and external iliac lymph nodes, 2.9% (15 of 524 patients) in the common iliac lymph nodes, 2.1% (11 of 524 patients) in the distal external iliac lymph nodes, and 1.7% (9 of 524 patients) in the para-aortic nodes. The incidence of isolated positive distal external iliac lymph nodes was 0.2%. Univariate analysis showed that lymphovascular space invasion, pelvic lymph node metastases (excluding distal external iliac lymph nodes) were significantly associated with distal external iliac lymph node metastasis (P < 0.05). Logistic regression analysis showed that pelvic lymph node metastasis (excluding distal external iliac lymph nodes) was the independent risk factor for metastasis to distal external iliac lymph nodes. In early stage cervical cancer, distal external iliac lymph node metastasis is rare, especially in cases with stage IA or without pelvic lymph node metastasis. Less extensive pelvic lymphadenectomy may be considered in these patients in order to reduce operative complications and improve patients' quality of life. The deep circumflex iliac vein may be an

Developmental cascades: Externalizing, internalizing, and academic competence from middle childhood to early adolescence

PubMed Central

Moilanen, Kristin L.; Shaw, Daniel S.; Maxwell, Kari L.

2011-01-01

The current study was initiated to increase understanding of developmental cascades in childhood in a sample of at-risk boys (N = 291; 52% White). Mothers, teachers, and boys reported on boys’ externalizing problems, internalizing difficulties, and academic competence. Consistent with hypotheses regarding school-related transitions, high levels of externalizing problems were associated with both low levels of academic competence and high levels of internalizing problems during the early school-age period, and with elevations in internalizing problems during the transition to adolescence. Low levels of academic competence were associated with high levels of internalizing problems in middle childhood, and with high levels of externalizing problems during the transition from elementary school to middle school. Shared risk factors played a minimal role in these developmental cascades. Results suggest that there are cascading effects of externalizing problems and academic competence in childhood and early adolescence, and that some cascading effects are more likely to occur during periods of school-related transitions. Implications of developmental cascade effects for research and intervention are discussed. PMID:20576184

Endogenous versus exogenous shocks in systems with memory

NASA Astrophysics Data System (ADS)

Sornette, D.; Helmstetter, A.

2003-02-01

Systems with long-range persistence and memory are shown to exhibit different precursory as well as recovery patterns in response to shocks of exogenous versus endogenous origins. By endogenous, we envision either fluctuations resulting from an underlying chaotic dynamics or from a stochastic forcing origin which may be external or be an effective coarse-grained description of the microscopic fluctuations. In this scenario, endogenous shocks result from a kind of constructive interference of accumulated fluctuations whose impacts survive longer than the large shocks themselves. As a consequence, the recovery after an endogenous shock is in general slower at early times and can be at long times either slower or faster than after an exogenous perturbation. This offers the tantalizing possibility of distinguishing between an endogenous versus exogenous cause of a given shock, even when there is no “smoking gun”. This could help in investigating the exogenous versus self-organized origins in problems such as the causes of major biological extinctions, of change of weather regimes and of the climate, in tracing the source of social upheaval and wars, and so on. Sornette et al., Volatility fingerprints of large stocks: endogenous versus exogenous, cond-mat/0204626 has already shown how this concept can be applied concretely to differentiate the effects on financial markets of the 11 September 2001 attack or of the coup against Gorbachev on 19 August 1991 (exogenous) from financial crashes such as October 1987 (endogenous).

Early Treatment in Shock

DTIC Science & Technology

2007-06-01

Dehydroepiandrosterone protects muscle flap microcirculatory hemodynamics from ischemia / reperfusion injury : an experimental in vivo study. J Trauma. 1997...haemorrhagic shock and reperfusion . British J of Pharmacol, 1986; 89:149-155 2 . Van Way, CW III, Dhar, A, Reddy R, Evans, L, Wogahn B, Helling TS. Changes in...grammed cell death, apoptosis, is a major pathway causing reperfusion injury . During apoptosis, cytosolic cytochrome-c is released from damaged

Liberal Versus Restrictive Intravenous Fluid Therapy for Early Septic Shock: Rationale for a Randomized Trial.

PubMed

Self, Wesley H; Semler, Matthew W; Bellomo, Rinaldo; Brown, Samuel M; deBoisblanc, Bennett P; Exline, Matthew C; Ginde, Adit A; Grissom, Colin K; Janz, David R; Jones, Alan E; Liu, Kathleen D; Macdonald, Stephen P J; Miller, Chadwick D; Park, Pauline K; Reineck, Lora A; Rice, Todd W; Steingrub, Jay S; Talmor, Daniel; Yealy, Donald M; Douglas, Ivor S; Shapiro, Nathan I

2018-05-09

Prompt intravenous fluid therapy is a fundamental treatment for patients with septic shock. However, the optimal approach for administering intravenous fluid in septic shock resuscitation is unknown. Two competing strategies are emerging: a liberal fluids approach, consisting of a larger volume of initial fluid (50 to 75 mL/kg [4 to 6 L in an 80-kg adult] during the first 6 hours) and later use of vasopressors, versus a restrictive fluids approach, consisting of a smaller volume of initial fluid (≤30 mL/kg [≤2 to 3 L]), with earlier reliance on vasopressor infusions to maintain blood pressure and perfusion. Early fluid therapy may enhance or maintain tissue perfusion by increasing venous return and cardiac output. However, fluid administration may also have deleterious effects by causing edema within vital organs, leading to organ dysfunction and impairment of oxygen delivery. Conversely, a restrictive fluids approach primarily relies on vasopressors to reverse hypotension and maintain perfusion while limiting the administration of fluid. Both strategies have some evidence to support their use but lack robust data to confirm the benefit of one strategy over the other, creating clinical and scientific equipoise. As part of the National Heart, Lung, and Blood Institute Prevention and Early Treatment of Acute Lung Injury Network, we designed a randomized clinical trial to compare the liberal and restrictive fluids strategies, the Crystalloid Liberal or Vasopressor Early Resuscitation in Sepsis trial. The purpose of this article is to review the current literature on approaches to early fluid resuscitation in adults with septic shock and outline the rationale for the upcoming trial. Copyright © 2018 American College of Emergency Physicians. Published by Elsevier Inc. All rights reserved.

Numerical modeling of the early interaction of a planar shock with a dense particle field

NASA Astrophysics Data System (ADS)

Regele, Jonathan; Blanquart, Guillaume

2011-11-01

Dense compressible multiphase flows are of interest for multiphase turbomachinary and energetic material detonations. Still, there is little understanding of the detailed interaction mechanisms between shock waves and dense (particle volume fraction αd > 0 . 001) particle fields. A recent experimental study [Wagner et al, AIAA Aero. Sci., Orlando, 2011-188] has focused on the impingement of a planar shock wave on a dense particle curtain. In the present work, numerical solutions of the Euler equations in one and two dimensions are performed for a planar shock wave impinging on a fixed particle curtain and are compared to the experimental data for early times. Comparison of the one- and two-dimensional results demonstrate that the one-dimensional description captures the large scale flow behavior, but is inadequate to capture all the details observed in the experiments. The two-dimensional solutions are shown to reproduce the experimentally observed flow structures and provide insight into how these details originate.

Reduction of initial shock in decadal predictions using a new initialization strategy

NASA Astrophysics Data System (ADS)

He, Yujun; Wang, Bin; Liu, Mimi; Liu, Li; Yu, Yongqiang; Liu, Juanjuan; Li, Ruizhe; Zhang, Cheng; Xu, Shiming; Huang, Wenyu; Liu, Qun; Wang, Yong; Li, Feifei

2017-08-01

A novel full-field initialization strategy based on the dimension-reduced projection four-dimensional variational data assimilation (DRP-4DVar) is proposed to alleviate the well-known initial shock occurring in the early years of decadal predictions. It generates consistent initial conditions, which best fit the monthly mean oceanic analysis data along the coupled model trajectory in 1 month windows. Three indices to measure the initial shock intensity are also proposed. Results indicate that this method does reduce the initial shock in decadal predictions by Flexible Global Ocean-Atmosphere-Land System model, Grid-point version 2 (FGOALS-g2) compared with the three-dimensional variational data assimilation-based nudging full-field initialization for the same model and is comparable to or even better than the different initialization strategies for other fifth phase of the Coupled Model Intercomparison Project (CMIP5) models. Better hindcasts of global mean surface air temperature anomalies can be obtained than in other FGOALS-g2 experiments. Due to the good model response to external forcing and the reduction of initial shock, higher decadal prediction skill is achieved than in other CMIP5 models.

Gene-by-Preschool Interaction on the Development of Early Externalizing Problems

ERIC Educational Resources Information Center

Tucker-Drob, Elliot M.; Harden, K. Paige

2013-01-01

Background: Preschool involves an array of new social experiences that may impact the development of early externalizing behavior problems over the transition to grade school. Methods: Using longitudinal data from a nationally representative sample of over 600 pairs of US twins, we tested whether the genetic and environmental influences on…

Early Treatment in Shock

DTIC Science & Technology

2010-06-17

the present study was that pre-feeding experimental animals with 8 fish oil rich in • -3 fatty acids (FAs), specifically eicosapentaenoic acid (EPA...Précis of presentation to be given at ESPEN 2010, 24-28 August, 2010 2. Manuscript on use of omega-3 fatty acids in shock, accepted for publication...use of DHEA, but studies in our laboratories have failed to show a useful effect (6). Studies with omega-3 fatty acids have shown promise, but are

Early Adolescent Friendship Selection Based on Externalizing Behavior: the Moderating Role of Pubertal Development. The SNARE Study.

PubMed

Franken, Aart; Prinstein, Mitchell J; Dijkstra, Jan Kornelis; Steglich, Christian E G; Harakeh, Zeena; Vollebergh, Wilma A M

2016-11-01

This study examined friendship (de-)selection processes in early adolescence. Pubertal development was examined as a potential moderator. It was expected that pubertal development would be associated with an increased tendency for adolescents to select their friends based on their similarities in externalizing behavior engagement (i.e., delinquency, alcohol use, and tobacco use). Data were used from the first three waves of the SNARE (Social Network Analysis of Risk behavior in Early adolescence) study (N = 1144; 50 % boys; M age  = 12.7; SD = 0.47), including students who entered the first year of secondary school. The hypothesis was tested using Stochastic Actor-Based Modeling in SIENA. While taking the network structure into account, and controlling for peer influence effects, the results supported this hypothesis. Early adolescents with higher pubertal development were as likely as their peers to select friends based on similarity in externalizing behavior and especially likely to remain friends with peers who had a similar level of externalizing behavior, and thus break friendship ties with dissimilar friends in this respect. As early adolescents are actively engaged in reorganizing their social context, adolescents with a higher pubertal development are especially likely to lose friendships with peers who do not engage in externalizing behavior, thus losing an important source of adaptive social control (i.e., friends who do not engage in externalizing behavior).

On a Stochastic Failure Model under Random Shocks

NASA Astrophysics Data System (ADS)

Cha, Ji Hwan

2013-02-01

In most conventional settings, the events caused by an external shock are initiated at the moments of its occurrence. In this paper, we study a new classes of shock model, where each shock from a nonhomogeneous Poisson processes can trigger a failure of a system not immediately, as in classical extreme shock models, but with delay of some random time. We derive the corresponding survival and failure rate functions. Furthermore, we study the limiting behaviour of the failure rate function where it is applicable.

Early prediction of norepinephrine dependency and refractory septic shock with a multimodal approach of vascular failure.

PubMed

Conrad, Marie; Perez, Pierre; Thivilier, Carine; Levy, Bruno

2015-08-01

The purpose of the study is to improve our ability to detect catecholamine dependency and refractory septic shock. Fifty-one patients with septic shock were studied within the first 4 hours of norepinephrine administration. Patients were divided into 2 groups according to their evolution in the intensive care unit, namely, group A, shock reversal, and group B, no shock reversal. Reversal of shock was defined as the maintenance of a systolic blood pressure greater than or equal to 90 mm Hg without vasopressor support for 24 hours or more. Vascular reactivity was tested using incremental doses of phenylephrine. Muscle tissue oxygen saturation and its changes during a vascular occlusion test were measured. Group B patients had a higher Sequential Organ Failure Assessment (SOFA) score and lactate level and more frequently received norepinephrine and renal replacement. Overall mortality was 100% in group B (16/16) and 20% (7/35) in group A. Phenylephrine increased mean arterial pressure in a dose-dependent manner more significantly in group A patients than in group B (P = .0004). Basal tissue oxygen saturation and the recovery slope after vascular occlusion test were lower in group B. In multivariate analysis, 4 parameters remained independently associated with mortality: the increase in mean arterial pressure at phenylephrine 6 μg/kg per minute, the recovery slope, SOFA score, and norepinephrine doses at H0. The intensity of septic shock-induced vascular hyporesponsiveness to vasopressor is tightly linked to septic shock severity and evolution and may potentially be identified early with simple to obtain parameters such as near-infrared spectroscopy value, SOFA score, or norepinephrine dose. Copyright © 2015 Elsevier Inc. All rights reserved.

Social Status of Adolescents with an Early Onset of Externalizing Behavior: The SNARE Study

ERIC Educational Resources Information Center

Franken, Aart; Harakeh, Zeena; Veenstra, Rene; Vollebergh, Wilma; Dijkstra, Jan Kornelis

2017-01-01

This study investigated the social status (i.e., popularity, likeability, and friendships) of adolescents with an early onset of externalizing behavior (i.e., alcohol use, tobacco use, and antisocial behavior). Building on Moffitt's dual-taxonomy model, it was hypothesized that early onset adolescents were more popular, but not necessarily more…

Early cumulative risk predicts externalizing behavior at age 10: The mediating role of adverse parenting.

PubMed

Gach, Emily J; Ip, Ka I; Sameroff, Arnold J; Olson, Sheryl L

2018-02-01

Multiple environmental risk factors in early childhood predict a broad range of adverse developmental outcomes. However, most prior longitudinal research has not illuminated explanatory mechanisms. Our main goals were to examine predictive associations between cumulative ecological risk factors in early childhood and children's later externalizing problems and to determine whether these associations were explained by variations in parenting quality. Participants were 241 children (118 girls) at risk for school-age conduct problems and their parents and teachers. Children were approximately 3 years old at Time 1 (T1) and 10 years old at Time 2 (T2). Reports of contextual risk at T1 were used to develop a cumulative risk index consisting of 6 singular risk variables from 3 ecological levels: social resources (low income; social isolation), family resources (marital aggression; poor total family functioning), and maternal resources (single parent status; poor maternal mental health). At T1, parenting variables were measured (corporal punishment, warm responsiveness, maternal efficacy, and negative perceptions of child behavior). At T2, mothers, fathers, and teachers reported child externalizing problems. Johnson's relative weight analysis revealed that the cumulative risk index was a more powerful predictor of age 10 years externalizing behavior than any of the singular contextual risk variables. Adverse parenting mediated the effects of cumulative risk on later child externalizing problems. Our findings have significant implications for understanding long-term effects of multiple contextual risk factors present in early childhood and for the implementation of positive parenting interventions early on. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Nonhuman primate model of polytraumatic hemorrhagic shock recapitulates early platelet dysfunction observed following severe injury in humans.

PubMed

Schaub, Leasha J; Moore, Hunter B; Cap, Andrew P; Glaser, Jacob J; Moore, Ernest E; Sheppard, Forest R

2017-03-01

Platelet dysfunction has been described as an early component of trauma-induced coagulopathy. The platelet component of trauma-induced coagulopathy remains to be fully elucidated and translatable animal models are required to facilitate mechanistic investigations. We sought to determine if the early platelet dysfunction described in trauma patients could be recapitulated in a nonhuman primate model of polytraumatic hemorrhagic shock. Twenty-four male rhesus macaques weighting 7 to 14 kg were subjected to 60 minutes (min) of severe pressure-targeted controlled hemorrhagic shock (HS) with and without other injuries. After 60 min, resuscitation with 0.9% NaCl and whole blood was initiated. Platelet counts and platelet aggregation assays were performed at baseline (BSLN), end of shock (EOS; T = 60 min), end of resuscitation (EOR; T = 180 min), and T = 360 min on overall cohort. Results are reported as mean ± standard deviation (SD) or median (interquartile range). Statistical analysis was conducted using Spearmen correlation, one-way analysis of variance, two-way repeated-measures analysis of variance, paired t-test or Wilcoxon nonparametric test, with p < 0.05 considered significant. Platelet count in all injury cohorts decreased over time, but no animals developed thrombocytopenia. Correlations were observed between platelet aggregation and platelet count for all agonists: adenosine diphosphate, thrombin recognition-activating peptide-6, collagen, and arachidonic acid. Overall, compared to BSLN, platelet aggregation decreased for all agonist at EOS, EOR, and T = 360 min. When normalized to platelet count, platelet aggregation in response to agonist thrombin recognition-activating peptide-6 demonstrated no change from BSLN at subsequent time points. Aggregation to adenosine diphosphate was significantly less at EOR but not EOS or T = 360 min compared to BSLN. Platelet aggregation to collagen and arachidonic acid was not significantly different at EOS compared to BSLN

Are infants differentially sensitive to parenting? Early maternal care, DRD4 genotype and externalizing behavior during adolescence.

PubMed

Nikitopoulos, Jörg; Zohsel, Katrin; Blomeyer, Dorothea; Buchmann, Arlette F; Schmid, Brigitte; Jennen-Steinmetz, Christine; Becker, Katja; Schmidt, Martin H; Esser, Günter; Brandeis, Daniel; Banaschewski, Tobias; Laucht, Manfred

2014-12-01

Insensitive and unresponsive caregiving during infancy has been linked to externalizing behavior problems during childhood and adolescence. The 7-repeat (7r) allele of the dopamine D4 receptor (DRD4) gene has meta-analytically been associated with a heightened susceptibility to adverse as well as supportive environments. In the present study, we examined long-term effects of early maternal care, DRD4 genotype and the interaction thereof on externalizing and internalizing psychopathology during adolescence. As part of an ongoing epidemiological cohort study, early maternal care was assessed at child's age 3 months during a nursing and playing situation. In a sample of 296 offspring, externalizing and internalizing symptoms were assessed using a psychiatric interview conducted at age 15 years. Parents additionally filled out a questionnaire on their children's psychopathic behaviors. Results indicated that adolescents with the DRD4 7r allele who experienced less responsive and stimulating early maternal care exhibited more symptoms of ADHD and CD/ODD as well as higher levels of psychopathic behavior. In accordance with the hypothesis of differential susceptibility, 7r allele carriers showed fewer ADHD symptoms and lower levels of psychopathic behavior when exposed to especially beneficial early caregiving. In contrast, individuals without the DRD4 7r allele proved to be insensitive to the effects of early maternal care. This study replicates earlier findings with regard to an interaction between DRD4 genotype and early caregiving on externalizing behavior problems in preschoolers. It is the first one to imply continuity of this effect until adolescence. Copyright © 2014 Elsevier Ltd. All rights reserved.

Role of temperament in early adolescent pure and co-occurring internalizing and externalizing problems using a bifactor model: Moderation by parenting and gender.

PubMed

Wang, Frances L; Eisenberg, Nancy; Valiente, Carlos; Spinrad, Tracy L

2016-11-01

We contribute to the literature on the relations of temperament to externalizing and internalizing problems by considering parental emotional expressivity and child gender as moderators of such relations and examining prediction of pure and co-occurring problem behaviors during early to middle adolescence using bifactor models (which provide unique and continuous factors for pure and co-occurring internalizing and externalizing problems). Parents and teachers reported on children's (4.5- to 8-year-olds; N = 214) and early adolescents' (6 years later; N = 168) effortful control, impulsivity, anger, sadness, and problem behaviors. Parental emotional expressivity was measured observationally and with parents' self-reports. Early-adolescents' pure externalizing and co-occurring problems shared childhood and/or early-adolescent risk factors of low effortful control, high impulsivity, and high anger. Lower childhood and early-adolescent impulsivity and higher early-adolescent sadness predicted early-adolescents' pure internalizing. Childhood positive parental emotional expressivity more consistently related to early-adolescents' lower pure externalizing compared to co-occurring problems and pure internalizing. Lower effortful control predicted changes in externalizing (pure and co-occurring) over 6 years, but only when parental positive expressivity was low. Higher impulsivity predicted co-occurring problems only for boys. Findings highlight the probable complex developmental pathways to adolescent pure and co-occurring externalizing and internalizing problems.

Implementation of a Cardiogenic Shock Team and Clinical Outcomes (INOVA-SHOCK Registry): Observational and Retrospective Study.

PubMed

Tehrani, Behnam; Truesdell, Alexander; Singh, Ramesh; Murphy, Charles; Saulino, Patricia

2018-06-28

The development and implementation of a Cardiogenic Shock initiative focused on increased disease awareness, early multidisciplinary team activation, rapid initiation of mechanical circulatory support, and hemodynamic-guided management and improvement of outcomes in cardiogenic shock. The objectives of this study are (1) to collect retrospective clinical outcomes for acute decompensated heart failure cardiogenic shock and acute myocardial infarction cardiogenic shock, and compare current versus historical survival rates and clinical outcomes; (2) to evaluate Inova Heart and Vascular Institute site specific outcomes before and after initiation of the Cardiogenic Shock team on January 1, 2017; (3) to compare outcomes related to early implementation of mechanical circulatory support and hemodynamic-guided management versus historical controls; (4) to assess survival to discharge rate in patients receiving intervention from the designated shock team and (5) create a clinical archive of Cardiogenic Shock patient characteristics for future analysis and the support of translational research studies. This is an observational, retrospective, single center study. Retrospective and prospective data will be collected in patients treated at the Inova Heart and Vascular Institute with documented cardiogenic shock as a result of acute decompensated heart failure or acute myocardial infarction. This registry will include data from patients prior to and after the initiation of the multidisciplinary Cardiogenic Shock team on January 1, 2017. Clinical outcomes associated with early multidisciplinary team intervention will be analyzed. In the study group, all patients evaluated for documented cardiogenic shock (acute decompensated heart failure cardiogenic shock, acute myocardial infarction cardiogenic shock) treated at the Inova Heart and Vascular Institute by the Cardiogenic Shock team will be included. An additional historical Inova Heart and Vascular Institute control group will

Physiology and Endocrinology Symposium: The current status of heat shock in early embryonic survival and reproductive efficiency

USDA-ARS?s Scientific Manuscript database

The Physiology and Endocrinology Symposium entitled “The Current Status of Heat Shock in Early Embryonic Survival and Reproductive Efficiency” was held at the Joint ADSA-CSAS-AMPA-WSAS-ASAS Meeting in Phoenix, Arizona, July 15 to 19, 2012. In recent years, data has accumulated suggesting a role for...

Parental Depression, Overreactive Parenting, and Early Childhood Externalizing Problems: Moderation by Social Support.

PubMed

Taraban, Lindsay; Shaw, Daniel S; Leve, Leslie D; Natsuaki, Misaki N; Ganiban, Jody M; Reiss, David; Neiderhiser, Jenae M

2018-02-20

This study used a large (N = 519), longitudinal sample of adoptive families to test overreactive parenting as a mediator of associations between parental depressive symptoms and early childhood externalizing, and parents' social support satisfaction as a moderator. Maternal parenting (18 months) mediated the association between maternal depressive symptoms (9 months) and child externalizing problems (27 months). Paternal parenting was not a significant mediator. Unexpectedly, we found a cross-over effect for the moderating role of social support satisfaction, such that partners' social support satisfaction reduced the strength of the association between each parent's own depressive symptoms and overreactive parenting. Results point to the importance of accounting for broader family context in predicting early childhood parenting and child outcomes. © 2018 The Authors. Child Development © 2018 Society for Research in Child Development, Inc.

Heat shock protein antagonists in early stage clinical trials for NSCLC.

PubMed

Hendriks, Lizza E L; Dingemans, Anne-Marie C

2017-05-01

Cancer cells have a higher need of chaperones than normal cells to prevent the toxic effects of intracellular protein misfolding and aggregation. Heat shock proteins (Hsps) belong to these chaperones; they are classified into families according to molecular size. Hsps are upregulated in many cancers and inhibition can inhibit tumor growth by destabilizing proteins necessary for tumor survival. In non-small cell lung cancer (NSCLC), there are three different Hsp antagonist classes that are in (early) clinical trials: Hsp90, Hsp70 and Hsp27 inhibitors. Areas covered: The rationale to use Hsp inhibitors in NSCLC will be summarized and phase I-III trials will be reviewed. Expert opinion: Several Hsp90 inhibitors have been tested in phase I-III trials, until now none was positive in unselected NSCLC; therefore development of AUY922, ganetespib and retaspimycin was halted. Results seem more promising in molecularly selected patients, especially in ALK-rearranged NSCLC. Hsp27 is overexpressed in squamous NSCLC and is a mechanism of chemotherapy resistance. The Hsp27 inhibitor apatorsen is now tested in squamous NSCLC. No phase II/III data are known for Hsp70 inhibitors. Combination of Hsp inhibitors with heat shock transcription factor 1 inhibitors or focal adhesion kinase inhibitors might be of interest for future trials.

Identifying early pathways of risk and resilience: The codevelopment of internalizing and externalizing symptoms and the role of harsh parenting.

PubMed

Wiggins, Jillian Lee; Mitchell, Colter; Hyde, Luke W; Monk, Christopher S

2015-11-01

Psychological disorders co-occur often in children, but little has been done to document the types of conjoint pathways internalizing and externalizing symptoms may take from the crucial early period of toddlerhood or how harsh parenting may overlap with early symptom codevelopment. To examine symptom codevelopment trajectories, we identified latent classes of individuals based on internalizing and externalizing symptoms across ages 3-9 and found three symptom codevelopment classes: normative symptoms (low), severe-decreasing symptoms (initially high but rapidly declining), and severe symptoms (high) trajectories. Next, joint models examined how parenting trajectories overlapped with internalizing and externalizing symptom trajectories. These trajectory classes demonstrated that, normatively, harsh parenting increased after toddlerhood, but the severe symptoms class was characterized by a higher level and a steeper increase in harsh parenting and the severe-decreasing class by high, stable harsh parenting. In addition, a transactional model examined the bidirectional relationships among internalizing and externalizing symptoms and harsh parenting because they may cascade over time in this early period. Harsh parenting uniquely contributed to externalizing symptoms, controlling for internalizing symptoms, but not vice versa. In addition, internalizing symptoms appeared to be a mechanism by which externalizing symptoms increase. Results highlight the importance of accounting for both internalizing and externalizing symptoms from an early age to understand risk for developing psychopathology and the role harsh parenting plays in influencing these trajectories.

Early and Definitive Diagnosis of Toxic Shock Syndrome by Detection of Marked Expansion of T-Cell-Receptor Vβ2-Positive T Cells

PubMed Central

Kato, Hidehito; Yamada, Ritsuko; Okano, Hiroya; Ohta, Hiroaki; Imanishi, Ken’ichi; Kikuchi, Ken; Totsuka, Kyouichi; Uchiyama, Takehiko

2003-01-01

We describe two cases of early toxic shock syndrome, caused by the superantigen produced from methicillin-resistant Staphylococcus aureus and diagnosed on the basis of an expansion of T-cell-receptor Vβ2-positive T cells. One case-patient showed atypical symptoms. Our results indicate that diagnostic systems incorporating laboratory techniques are essential for rapid, definitive diagnosis of toxic shock syndrome. PMID:12643839

Early structural changes of the heart after experimental polytrauma and hemorrhagic shock

PubMed Central

Halbgebauer, Rebecca; Eisele, Philipp; Messerer, David A. C.; Weckbach, Sebastian; Schultze, Anke; Braumüller, Sonja; Gebhard, Florian

2017-01-01

Evidence is emerging that systemic inflammation after trauma drives structural and functional impairment of cardiomyocytes and leads to cardiac dysfunction, thus worsening the outcome of polytrauma patients. This study investigates the structural and molecular changes in heart tissue 4 h after multiple injuries with additional hemorrhagic shock using a clinically relevant rodent model of polytrauma. We determined mediators of systemic inflammation (keratinocyte chemoattractant, macrophage chemotactic protein 1), activated complement component C3a and cardiac troponin I in plasma and assessed histological specimen of the mouse heart via standard histomorphology and immunohistochemistry for cellular and subcellular damage and ongoing apoptosis. Further we investigated spatial and quantitative changes of connexin 43 by immunohistochemistry and western blotting. Our results show significantly increased plasma levels of both keratinocyte chemoattractant and cardiac troponin I 4 h after polytrauma and 2 h after induction of hypovolemia. Although we could not detect any morphological changes, immunohistochemical evaluation showed increased level of tissue high-mobility group box 1, which is both a damage-associated molecule and actively released as a danger response signal. Additionally, there was marked lateralization of the cardiac gap-junction protein connexin 43 following combined polytrauma and hemorrhagic shock. These results demonstrate a molecular manifestation of remote injury of cardiac muscle cells in the early phase after polytrauma and hemorrhagic shock with marked disruption of the cardiac gap junction. This disruption of an important component of the electrical conduction system of the heart may lead to arrhythmia and consequently to cardiac dysfunction. PMID:29084268

Role of temperament in early adolescent pure and co-occurring internalizing and externalizing problems using a bifactor model: Moderation by parenting and gender

PubMed Central

WANG, FRANCES L.; EISENBERG, NANCY; VALIENTE, CARLOS; SPINRAD, TRACY L.

2015-01-01

We contribute to the literature on the relations of temperament to externalizing and internalizing problems by considering parental emotional expressivity and child gender as moderators of such relations and examining prediction of pure and co-occurring problem behaviors during early to middle adolescence using bifactor models (which provide unique and continuous factors for pure and co-occurring internalizing and externalizing problems). Parents and teachers reported on children’s (4.5- to 8-year-olds; N = 214) and early adolescents’ (6 years later; N = 168) effortful control, impulsivity, anger, sadness, and problem behaviors. Parental emotional expressivity was measured observationally and with parents’ self-reports. Early-adolescents’ pure externalizing and co-occurring problems shared childhood and/or early-adolescent risk factors of low effortful control, high impulsivity, and high anger. Lower childhood and early-adolescent impulsivity and higher early-adolescent sadness predicted early-adolescents’ pure internalizing. Childhood positive parental emotional expressivity more consistently related to early-adolescents’ lower pure externalizing compared to co-occurring problems and pure internalizing. Lower effortful control predicted changes in externalizing (pure and co-occurring) over 6 years, but only when parental positive expressivity was low. Higher impulsivity predicted co-occurring problems only for boys. Findings highlight the probable complex developmental pathways to adolescent pure and co-occurring externalizing and internalizing problems. PMID:26646352

Early outcome of early-goal directed therapy for patients with sepsis or septic shock: a systematic review and meta-analysis of randomized controlled trials.

PubMed

Chen, Xiaofan; Zhu, Weifeng; Tan, Jing; Nie, Heyun; Liu, Liangming; Yan, Dongmei; Zhou, Xu; Sun, Xin

2017-04-18

Various trials and meta-analyses have reported conflicting results concerning the application of early goal-directed therapy (EGDT) for sepsis and septic shock. The aim of this study was to update the evidence by performing a systematic review and meta-analysis. Multiple databases were searched from initial through August, 2016 for randomized controlled trials (RCTs) which investigated the associations between the use of EGDT and mortality in patients with sepsis or septic shock. Meta-analysis was performed using random-effects model and heterogeneity was examined through subgroup analyses. The primary outcome of interest was patient all-cause mortality including hospital or ICU mortality. Seventeen RCTs including 6207 participants with 3234 in the EGDT group and 2973 in the control group were eligible for this study. Meta-analysis showed that EGDT did not significantly reduce hospital or intensive care unit (ICU) mortality (relative risk [RR] 0.89, 95% CI 0.78 to 1.02) compared with control group for patients with sepsis or septic shock. The findings of subgroup analyses stratified by study region, number of research center, year of enrollment, clinical setting, sample size, timing of EGDT almost remained constant with that of the primary analysis. Our findings provide evidence that EGDT offers neutral survival effects for patients with sepsis or septic shock. Further meta-analyses based on larger well-designed RCTs or individual patient data meta-analysis are required to explore the survival benefits of EDGT in patients with sepsis or septic shock.

Early Callous-Unemotional Behavior, Theory-of-mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood

PubMed Central

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W.; Olson, Sheryl L.

2016-01-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N=241; 48% female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior. PMID:26582182

Early Callous-Unemotional Behavior, Theory-of-Mind, and a Fearful/Inhibited Temperament Predict Externalizing Problems in Middle and Late Childhood.

PubMed

Song, Ju-Hyun; Waller, Rebecca; Hyde, Luke W; Olson, Sheryl L

2016-08-01

Childhood externalizing problems are more likely to be severe and persistent when combined with high levels of callous-unemotional (CU) behavior. A handful of recent studies have shown that CU behavior can also be reliably measured in the early preschool years, which may help to identify young children who are less likely to desist from early externalizing behaviors. The current study extends previous literature by examining the role of CU behavior in very early childhood in the prediction of externalizing problems in both middle and late childhood, and tests whether other relevant child characteristics, including Theory-of-Mind (ToM) and fearful/inhibited temperament moderate these pathways. Multi-method data, including parent reports of child CU behavior and fearful/inhibited temperament, observations of ToM, and teacher-reported externalizing problems were drawn from a prospective, longitudinal study of children assessed at ages 3, 6, and 10 (N = 241; 48 % female). Results demonstrated that high levels of CU behavior predicted externalizing problems at ages 6 and 10 over and above the effect of earlier externalizing problems at age 3, but that these main effects were qualified by two interactions. High CU behavior was related to higher levels of externalizing problems specifically for children with low ToM and a low fearful/inhibited temperament. The results show that a multitude of child characteristics likely interact across development to increase or buffer risk for child externalizing problems. These findings can inform the development of targeted early prevention and intervention for children with high CU behavior.

Laboratory Studies of Survival Limits of Bacteria During Shock Compression: Application to Impacts on the Early Earth

NASA Astrophysics Data System (ADS)

Willis, M. J.; Ahrens, T. J.; Bertani, L. E.; Nash, C. Z.

2004-12-01

Shock recovery experiments on suspensions of 106 mm-3 E. coli bacteria contained in water-based medium, within stainless steel containers, are used to simulate the impact environment of bacteria residing in water-filled cracks in rocks. Early Earth life is likely to have existed in such environments. Some 10-2 to 10-4 of the bacteria population survived initial (800 ns duration) shock pressures in water of 219 and 260 MPa. TEM images of shock recovered bacteria indicate cell wall indentations and rupture, possibly induced by inward invasion of medium into the cell wall. Notably cell wall rupture occurs dynamically at ˜0.1 times the static pressures E.coli have been demonstrated (Sharma et al., 2002) to survive and may be caused by Rayleigh-Taylor instabilities. We infer the invading fluid pressure may exceed the tensile strength of the cell wall. We assume the overpressures are limited to the initial shock pressure in water. Parameters for the Grady & Lipkin (1980) model of tensile failure versus time-scale (strain rate) are fit to present data, assuming that at low strain rates, overpressures exceeding cell Turgor pressure require ˜103 sec. This model, if validated by experiments at other timescales, may permit using short loading duration laboratory data to infer response of organisms to lower shock overpressures for the longer times (100 to 103 s) of planetary impacts. An Ahrens & O'Keefe (1987) shock attenuation model is then applied for Earth impactors. This model suggests that Earth impactors of radius 1.5 km induce shocks within water-filled cracks in rock to dynamic pressure such that stresses exceeding the survivability threshold of E. coli bacteria, to radii of 1.7-2.6×102 km. In contrast, a giant (1500 km radius) impactor produces a non survival zone for E. coli that encompasses the entire Earth.

Measurement of the shock front velocity produced in a T-tube

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

Djurović, S.; Mijatović, Z.; Vujičić, B.

2015-01-15

A set of shock front velocity measurements is described in this paper. The shock waves were produced in a small electromagnetically driven shock T-tube. Most of the measurements were performed in hydrogen. The shock front velocity measurements in other gases and the velocity of the gas behind the shock front were also analyzed, as well as the velocity dependence on applied input energy. Some measurements with an applied external magnetic field were also performed. The used method of shock front velocity is simple and was shown to be very reliable. Measured values were compared with the calculated ones for themore » incident and reflected shock waves.« less

Identifying early pathways of risk and resilience: The co-development of internalizing and externalizing symptoms and the role of harsh parenting

PubMed Central

Wiggins, Jillian Lee; Mitchell, Colter; Hyde, Luke W.; Monk, Christopher S.

2016-01-01

Psychological disorders co-occur often in children, but little has been done to document the types of conjoint pathways internalizing and externalizing symptoms may take from the crucial early period of toddlerhood or how harsh parenting may overlap with early symptom co-development. To examine symptom co-development trajectories, we identified latent classes of individuals based on internalizing and externalizing symptoms across ages 3–9 and found three symptom co-development classes: normative symptoms (low), severe-decreasing symptoms (initially high but rapidly declining) and severe symptoms (high) trajectories. Next, joint models examined how parenting trajectories overlapped with internalizing and externalizing symptom trajectories. These trajectory classes demonstrated that, normatively, harsh parenting increased after toddlerhood, but the severe symptoms class was characterized by a higher level and steeper increase in harsh parenting and the severe-decreasing class by high, stable harsh parenting. Additionally, a transactional model examined the bi-directional relationships among internalizing and externalizing symptoms and harsh parenting as they may cascade over time in this early period. Harsh parenting uniquely contributed to externalizing symptoms, controlling for internalizing symptoms, but not vice versa. Also, internalizing symptoms appeared to be a mechanism by which externalizing symptoms increase. Results highlight the importance accounting for both internalizing and externalizing symptoms from an early age to understand risk for developing psychopathology and the role harsh parenting plays in influencing these trajectories. PMID:26439075

Worldwide isotope ratios of the Fukushima release and early-phase external dose reconstruction

PubMed Central

Chaisan, Kittisak; Smith, Jim T.; Bossew, Peter; Kirchner, Gerald; Laptev, Gennady V.

2013-01-01

Measurements of radionuclides (RNs) in air made worldwide following the Fukushima accident are quantitatively compared with air and soil measurements made in Japan. Isotopic ratios RN:137Cs of 131I, 132Te, 134,136Cs, are correlated with distance from release. It is shown, for the first time, that both within Japan and globally, ratios RN:137Cs in air were relatively constant for primarily particle associated radionuclides (134,136Cs; 132Te) but that 131I shows much lower local (<80 km) isotope ratios in soils relative to 137Cs. Derived isotope ratios are used to reconstruct external dose rate during the early phase post-accident. Model “blind” tests show more than 95% of predictions within a factor of two of measurements from 15 sites to the north, northwest and west of the power station. It is demonstrated that generic isotope ratios provide a sound basis for reconstruction of early-phase external dose rates in these most contaminated areas. PMID:24018776

Differential risk for late adolescent conduct problems and mood dysregulation among children with early externalizing behavior problems.

PubMed

Okado, Yuko; Bierman, Karen L

2015-05-01

To investigate the differential emergence of antisocial behaviors and mood dysregulation among children with externalizing problems, the present study prospectively followed 317 high-risk children with early externalizing problems from school entry (ages 5-7) to late adolescence (ages 17-19). Latent class analysis conducted on their conduct and mood symptoms in late adolescence revealed three distinct patterns of symptoms, characterized by: 1) criminal offenses, conduct disorder symptoms, and elevated anger ("conduct problems"), 2) elevated anger, dysphoric mood, and suicidal ideation ("mood dysregulation"), and 3) low levels of severe conduct and mood symptoms. A diathesis-stress model predicting the first two outcomes was tested. Elevated overt aggression at school entry uniquely predicted conduct problems in late adolescence, whereas elevated emotion dysregulation at school entry uniquely predicted mood dysregulation in late adolescence. Experiences of low parental warmth and peer rejection in middle childhood moderated the link between early emotion dysregulation and later mood dysregulation but did not moderate the link between early overt aggression and later conduct problems. Thus, among children with early externalizing behavior problems, increased risk for later antisocial behavior or mood dysfunction may be identifiable in early childhood based on levels of overt aggression and emotion dysregulation. For children with early emotion dysregulation, however, increased risk for mood dysregulation characterized by anger, dysphoric mood, and suicidality--possibly indicative of disruptive mood dysregulation disorder--emerges only in the presence of low parental warmth and/or peer rejection during middle childhood.

Sex difference in the heat shock response to high external load resistance training in older humans.

PubMed

Njemini, Rose; Forti, Louis Nuvagah; Mets, Tony; Van Roie, Evelien; Coudyzer, Walter; Beyer, Ingo; Delecluse, Christophe; Bautmans, Ivan

2017-07-01

Literature reports on the effects of resistance training on heat shock protein70 (Hsp70) adaptation in older subjects are scarce. Moreover, the optimum training load required to obtain a beneficial adaptation profile is lacking. Therefore, the aim of this study was to determine the effects of resistance training at various external loads on extracellular Hsp70 (eHsp70) resting levels in older humans. Fifty-six community-dwelling older (68±5years) volunteers were randomized to 12weeks of resistance training (3×/week) at either high-resistance (HIGH, 8 males, 10 females, 2×10-15 repetitions at 80% 1RM), low resistance (LOW, 9 Males, 10 Females, 1×80-100 repetitions at 20% 1RM), or mixed low resistance (LOW+, 9 Males, 10 Females, 1×60 repetitions at 20% 1RM followed by 1×10-20 repetitions at 40% 1RM). Serum was available from 48 out of the 56 participants at baseline and after 12weeks for determination of eHsp70. Mid-thigh muscle volume (computed tomography), muscle strength (1RM & Biodex dynamometer) and physical functioning (including 6min walk distance [6MWD]) were assessed. There was a sex-related dichotomy in the heat shock response to high external load training. We observed a significant decrease in eHsp70 concentration in the HIGH group for female, but not male, subjects. At baseline, men had a larger muscle volume, leg press and leg extension 1RM compared to women (all p<0.001). Also, the 6MWD was significantly higher in men compared to women at baseline. However, this difference disappeared when correcting for height. Moreover, the overall functional performance and physical activity scores were similar in men and women. None of the participants' characteristics nor any of the outcome variables differed between groups at baseline. There was a significant increase in the strength and physical performance parameters in both men and women post-exercise (all p<0.05). Females in the HIGH group clearly demonstrated a larger gain in leg press 1RM and the

On Interplanetary Shocks Driven by Coronal Mass Ejections

NASA Technical Reports Server (NTRS)

Gopalswarmy, Nat

2011-01-01

Traveling interplanetary (IP) shocks were first detected in the early 1960s, but their solar origin has been controversial. Early research focused on solar flares as the source of the shocks, but when CMEs were discovered, it became clear that fast CMEs are the shock drivers. Type radio II bursts are excellent signatures of shocks near the Sun (Type II radio bursts were known long before the detection of shocks and CMEs). The excellent correspondence between type II bursts and solar energetic particle (SEP) events made it clear that the same shock accelerates ions and electrons. Shocks near the Sun are also seen occasionally in white-light coronagraphic images. In the solar wind, shocks are observed as discontinuities in plasma parameters such as density and speed. Energetic storm particle events and sudden commencement of geomagnetic storm are also indicators of shocks arriving at Earth. After an overview on these shock signatures, I will summarize the results of a recent investigation of a large number of IP shocks. The study revealed that about 35% of IP shocks do not produce type II bursts (radio quiet - RQ) or SEPs. Comparing the RQ shocks with the radio loud (RL) ones revealed some interesting results: (1) There is no evidence for blast wave shocks. (2) A small fraction (20%) of RQ shocks is associated with ion enhancements at the shock when the shock passes the spacecraft. (3) The primary difference between the RQ and RL shocks can be traced to the different kinematic properties of the associated CMEs. On the other hand the shock properties measured at 1 AU are not too different for the RQ and RL cases. This can be attributed to the interaction with the IP medium, which seems to erase the difference between the shocks.

[Streptococcal toxic shock syndrome].

PubMed

Gvozdenović, Ljiljana; Pasternak, Janko; Milovanović, Stanislav; Ivanov, Dejan; Milić, Sasa

2010-01-01

Streptococcal toxic shock syndrome is now recognized as a toxin-mediated, multisystem illness. It is characterized by an early onset of shock with multiorgan failure and continues to be associated with high morbidity and mortality, caused by group A Streptococcus pyogenes. The symptoms for staphylococcal and streptococcal toxic shock syndrome are similar. Streptococcal toxic shock syndrome was not well described until 1993, when children who had suffered from varicella presented roughly 2-4 weeks later with a clinical syndrome highly suggestive of toxic shock syndrome. It is characterized by a sudden onset of fever, chills, vomiting, diarrhea, muscle aches and rash. It can rapidly progress to severe and intractable hypotension and multisystem dysfunction. Almost every organ system can he involved. Complications of streptococcal toxic shock syndrome may include kidney failure, liver failure (and even death. Crystalloids and inotropic agents are used to treat the hypovolemic shock aggressively, with close monitoring of the patient's mean arterial pressure and central venous pressure. An immediate and aggressive management of hypovolemic shock is essential in streptococcal toxic shock syndrome. Targeted antibiotics are indicated: penicillin or a beta-lactam antibiotic is used for treating group A streptococci, and clindamycin has emerged as a key portion of the standard treatment.

Early Parenting and the Development of Externalizing Behavior Problems: Longitudinal Mediation Through Children's Executive Function.

PubMed

Sulik, Michael J; Blair, Clancy; Mills-Koonce, Roger; Berry, Daniel; Greenberg, Mark

2015-01-01

Path analysis was used to investigate the longitudinal associations among parenting and children's executive function and externalizing behavior problems from 36 to 90 months of age in the Family Life Project (N = 1,115), a study of child development in the context of rural poverty. While controlling for stability in the constructs, semistructured observations of parenting prospectively predicted performance on a battery of executive function tasks and primary caregivers' reports of externalizing behavior. Furthermore, the association between early parenting and later externalizing behavior was longitudinally mediated by executive function, providing support for a process model in which sensitive parenting promotes children's self-regulation, which in turn reduces children's externalizing behavior. © 2015 The Authors. Child Development © 2015 Society for Research in Child Development, Inc.

Shock wave propagation in a magnetic flux tube

NASA Astrophysics Data System (ADS)

Ferriz-Mas, A.; Moreno-Insertis, F.

1992-12-01

The propagation of a shock wave in a magnetic flux tube is studied within the framework of the Brinkley-Kirkwood theory adapted to a radiating gas. Simplified thermodynamic paths along which the compressed plasma returns to its initial state are considered. It is assumed that the undisturbed medium is uniform and that the flux tube is optically thin. The shock waves investigated, which are described with the aid of the thin flux-tube approximation, are essentially slow magnetohydrodynamic shocks modified by the constraint of lateral pressure balance between the flux tube and the surrounding field-free fluid; the confining external pressure must be balanced by the internal gas plus magnetic pressures. Exact analytical solutions giving the evolution of the shock wave are obtained for the case of weak shocks.

Effects of early maternal distress and parenting on the development of children's self-regulation and externalizing behavior.

PubMed

Choe, Daniel Ewon; Olson, Sheryl L; Sameroff, Arnold J

2013-05-01

Emotional distress experienced by mothers increases young children's risk of externalizing problems through suboptimal parenting and child self-regulation. An integrative structural equation model tested hypotheses that mothers' parenting (i.e., low levels of inductive discipline and maternal warmth) would mediate adverse effects of early maternal distress on child effortful control, which in turn would mediate effects of maternal parenting on child externalizing behavior. This longitudinal study spanning ages 3, 6, and 10 included 241 children, mothers, and a subset of teachers. The hypothesized model was partially supported. Elevated maternal distress was associated with less inductive discipline and maternal warmth, which in turn were associated with less effortful control at age 3 but not at age 6. Inductive discipline and maternal warmth mediated adverse effects of maternal distress on children's effortful control. Less effortful control at ages 3 and 6 predicted smaller relative decreases in externalizing behavior at 6 and 10, respectively. Effortful control mediated effects of inductive discipline, but not maternal warmth, on externalizing behavior. Findings suggest elevated maternal distress increases children's risk of externalizing problems by compromising early parenting and child self-regulation.

Serotonin transporter linked polymorphic region (5-HTTLPR) genotype moderates the longitudinal impact of early caregiving on externalizing behavior.

PubMed

Brett, Zoë H; Humphreys, Kathryn L; Smyke, Anna T; Gleason, Mary Margaret; Nelson, Charles A; Zeanah, Charles H; Fox, Nathan A; Drury, Stacy S

2015-02-01

We examined caregiver report of externalizing behavior from 12 to 54 months of age in 102 children randomized to care as usual in institutions or to newly created high-quality foster care. At baseline no differences by group or genotype in externalizing were found. However, changes in externalizing from baseline to 42 months of age were moderated by the serotonin transporter linked polymorphic region genotype and intervention group, where the slope for short-short (S/S) individuals differed as a function of intervention group. The slope for individuals carrying the long allele did not significantly differ between groups. At 54 months of age, S/S children in the foster care group had the lowest levels of externalizing behavior, while children with the S/S genotype in the care as usual group demonstrated the highest rates of externalizing behavior. No intervention group differences were found in externalizing behavior among children who carried the long allele. These findings, within a randomized controlled trial of foster care compared to continued care as usual, indicate that the serotonin transporter linked polymorphic region genotype moderates the relation between early caregiving environments to predict externalizing behavior in children exposed to early institutional care in a manner most consistent with differential susceptibility.

Differential Risk for Late Adolescent Conduct Problems and Mood Dysregulation Among Children with Early Externalizing Behavior Problems

PubMed Central

Bierman, Karen L.

2016-01-01

To investigate the differential emergence of antisocial behaviors and mood dysregulation among children with externalizing problems, the present study prospectively followed 317 high-risk children with early externalizing problems from school entry (ages 5–7) to late adolescence (ages 17–19). Latent class analysis conducted on their conduct and mood symptoms in late adolescence revealed three distinct patterns of symptoms, characterized by: 1) criminal offenses, conduct disorder symptoms, and elevated anger (“conduct problems”), 2) elevated anger, dysphoric mood, and suicidal ideation (“mood dysregulation”), and 3) low levels of severe conduct and mood symptoms. A diathesis-stress model predicting the first two outcomes was tested. Elevated overt aggression at school entry uniquely predicted conduct problems in late adolescence, whereas elevated emotion dysregulation at school entry uniquely predicted mood dysregulation in late adolescence. Experiences of low parental warmth and peer rejection in middle childhood moderated the link between early emotion dysregulation and later mood dysregulation but did not moderate the link between early overt aggression and later conduct problems. Thus, among children with early externalizing behavior problems, increased risk for later antisocial behavior or mood dysfunction may be identifiable in early childhood based on levels of overt aggression and emotion dysregulation. For children with early emotion dysregulation, however, increased risk for mood dysregulation characterized by anger, dysphoric mood, and suicidality – possibly indicative of disruptive mood dysregulation disorder – emerges only in the presence of low parental warmth and/or peer rejection during middle childhood. PMID:25183553

Muscle oxygenation as an early predictor of shock severity in trauma patients

PubMed Central

Arakaki, Lorilee S. L.; Bulger, Eileen M.; Ciesielski, Wayne A.; Carlbom, David J.; Fisk, Dana M.; Sheehan, Kellie L.; Asplund, Karin M.; Schenkman, Kenneth A.

2016-01-01

Introduction We evaluated the potential utility of a new prototype noninvasive muscle oxygenation (MOx) measurement for the identification of shock severity in a population of patients admitted to the trauma resuscitation rooms of a Level I regional trauma center. The goal of this project was to correlate MOx with shock severity as defined by standard measures of shock: systolic blood pressure, heart rate, and lactate. Methods Optical spectra were collected from subjects by placement of a custom-designed optical probe over the first dorsal interosseous muscles on the back of the hand. Spectra were acquired from trauma patients as soon as possible upon admission to the trauma resuscitation room. Patients with any injury were eligible for study. MOx was determined from the collected optical spectra with a multi-wavelength analysis that used both visible and near-infrared regions of light. Shock severity was determined in each patient by a scoring system based on combined degrees of hypotension, tachycardia, and lactate. MOx values of patients in each shock severity group (mild, moderate, and severe) were compared using two-sample t-tests. Results In 17 healthy control patients, the mean MOx value was 91.0 ± 5.5%. A total of 69 trauma patients were studied. Patients classified as having mild shock had a mean MOx of 62.5 ± 26.2% (n = 33), those classified as in moderate shock had a mean MOx of 56.9 ± 26.9% (n = 25) and those classified as in severe shock had a MOx of 31.0 ± 17.1% (n = 11). Mean MOx for each of these groups was statistically different from the healthy control group (p<0.05). Receiver operating characteristic (ROC) analyses show that MOx and shock index (heart rate/systolic blood pressure) identified shock similarly well (area under the curves (AUC) = 0.857 and 0.828, respectively). However, MOx identified mild shock better than shock index in the same group of patients (AUC = 0.782 and 0.671, respectively). Conclusions The results obtained from this

Pharmacy students' retention of knowledge and skills following training in automated external defibrillator use.

PubMed

Kopacek, Karen Birckelbaw; Dopp, Anna Legreid; Dopp, John M; Vardeny, Orly; Sims, J Jason

2010-08-10

To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education.

Early Parenting and the Development of Externalizing Behavior Problems: Longitudinal Mediation through Children’s Executive Function

PubMed Central

Sulik, Michael J.; Blair, Clancy; Mills-Koonce, Roger; Berry, Daniel; Greenberg, Mark

2015-01-01

Path analysis was used to investigate the longitudinal associations among parenting and children’s executive function and externalizing behavior problems from 36 to 90 months of age in the Family Life Project (N = 1,115), a study of child development in the context of rural poverty. While controlling for stability in the constructs, semi-structured observations of parenting prospectively predicted performance on a battery of executive function tasks and primary caregivers’ reports of externalizing behavior. Furthermore, the association between early parenting and later externalizing behavior was longitudinally mediated by executive function, providing support for a process model in which sensitive parenting promotes children’s self-regulation, which in turn reduces children’s externalizing behavior. PMID:26082032

Organic synthesis in experimental impact shocks

NASA Technical Reports Server (NTRS)

McKay, C. P.; Borucki, W. J.

1997-01-01

Laboratory simulations of shocks created with a high-energy laser demonstrate that the efficacy of organic production depends on the molecular, not just the elemental composition of the shocked gas. In a methane-rich mixture that simulates a low-temperature equilibrium mixture of cometary material, hydrogen cyanide and acetylene were produced with yields of 5 x 10(17) molecules per joule. Repeated shocking of the methane-rich mixture produced amine groups, suggesting the possible synthesis of amino acids. No organic molecules were produced in a carbon dioxide-rich mixture, which is at odds with thermodynamic equilibrium approaches to shock chemistry and has implications for the modeling of shock-produced organic molecules on early Earth.

Dislocation structure produced by an ultrashort shock pulse

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

Matsuda, Tomoki, E-mail: t-matsu@mapse.eng.osaka-u.ac.jp; Hirose, Akio; Sano, Tomokazu

We found an ultrashort shock pulse driven by a femtosecond laser pulse on iron generates a different dislocation structure than the shock process which is on the nanosecond timescale. The ultrashort shock pulse produces a highly dense dislocation structure that varies by depth. According to transmission electron microscopy, dislocations away from the surface produce microbands via a network structure similar to a long shock process, but unlike a long shock process dislocations near the surface have limited intersections. Considering the dislocation motion during the shock process, the structure near the surface is attributed to the ultrashort shock duration. This approachmore » using an ultrashort shock pulse will lead to understanding the whole process off shock deformation by clarifying the early stage.« less

Effect of Early Vasopressin vs Norepinephrine on Kidney Failure in Patients With Septic Shock: The VANISH Randomized Clinical Trial.

PubMed

Gordon, Anthony C; Mason, Alexina J; Thirunavukkarasu, Neeraja; Perkins, Gavin D; Cecconi, Maurizio; Cepkova, Magda; Pogson, David G; Aya, Hollmann D; Anjum, Aisha; Frazier, Gregory J; Santhakumaran, Shalini; Ashby, Deborah; Brett, Stephen J

2016-08-02

Norepinephrine is currently recommended as the first-line vasopressor in septic shock; however, early vasopressin use has been proposed as an alternative. To compare the effect of early vasopressin vs norepinephrine on kidney failure in patients with septic shock. A factorial (2×2), double-blind, randomized clinical trial conducted in 18 general adult intensive care units in the United Kingdom between February 2013 and May 2015, enrolling adult patients who had septic shock requiring vasopressors despite fluid resuscitation within a maximum of 6 hours after the onset of shock. Patients were randomly allocated to vasopressin (titrated up to 0.06 U/min) and hydrocortisone (n = 101), vasopressin and placebo (n = 104), norepinephrine and hydrocortisone (n = 101), or norepinephrine and placebo (n = 103). The primary outcome was kidney failure-free days during the 28-day period after randomization, measured as (1) the proportion of patients who never developed kidney failure and (2) median number of days alive and free of kidney failure for patients who did not survive, who experienced kidney failure, or both. Rates of renal replacement therapy, mortality, and serious adverse events were secondary outcomes. A total of 409 patients (median age, 66 years; men, 58.2%) were included in the study, with a median time to study drug administration of 3.5 hours after diagnosis of shock. The number of survivors who never developed kidney failure was 94 of 165 patients (57.0%) in the vasopressin group and 93 of 157 patients (59.2%) in the norepinephrine group (difference, -2.3% [95% CI, -13.0% to 8.5%]). The median number of kidney failure-free days for patients who did not survive, who experienced kidney failure, or both was 9 days (interquartile range [IQR], 1 to -24) in the vasopressin group and 13 days (IQR, 1 to -25) in the norepinephrine group (difference, -4 days [95% CI, -11 to 5]). There was less use of renal replacement therapy in the vasopressin group

Modeling the Early Afterglow in the Short and Hard GRB 090510

NASA Astrophysics Data System (ADS)

Fraija, N.; Lee, W. H.; Veres, P.; Barniol Duran, R.

2016-11-01

The bright, short, and hard GRB 090510 was detected by all instruments aboard the Fermi and Swift satellites. The multiwavelength observations of this burst presented similar features to the Fermi-LAT-detected gamma-ray bursts. In the framework of the external shock model of early afterglow, a leptonic scenario that evolves in a homogeneous medium is proposed to revisit GRB 090510 and explain the multiwavelength light curve observations presented in this burst. These observations are consistent with the evolution of a jet before and after the jet break. The long-lasting LAT, X-ray, and optical fluxes are explained in the synchrotron emission from the adiabatic forward shock. Synchrotron self-Compton emission from the reverse shock is consistent with the bright LAT peak provided that the progenitor environment is entrained with strong magnetic fields. It could provide compelling evidence of magnetic field amplification in the neutron star merger.

Predicting externalizing and internalizing behavior in kindergarten: examining the buffering role of early social support.

PubMed

Heberle, Amy E; Krill, Sarah C; Briggs-Gowan, Margaret J; Carter, Alice S

2015-01-01

This study tested an ecological model predicting children's behavior problems in kindergarten from risk and protective factors (parent psychological distress, parenting behavior, and social support) during early childhood. Study participants were 1,161 sociodemographically diverse mother-child pairs that participated in a longitudinal birth cohort study. The predictor variables were collected at two separate time points and based on parent reports; children were an average of 2 years old at Time 1 and 3 years old at Time 2. The outcome measures were collected when children reached kindergarten and were 6 years old on average. Our results show that early maternal psychological distress, mediated by suboptimal parenting behavior, predicts children's externalizing and internalizing behaviors in kindergarten. Moreover, early social support buffers the relations between psychological distress and later suboptimal parenting behavior and between suboptimal parenting behavior and later depressive/withdrawn behavior. Our findings have several implications for early intervention and prevention efforts. Of note, informal social support appears to play an important protective role in the development of externalizing and internalizing behavior problems, weakening the link between psychological distress and less optimal parenting behavior and between suboptimal parenting behavior and children's withdrawal/depression symptoms. Increasing social support may be a productive goal for family and community-level intervention.

Relativistic simulations of long-lived reverse shocks in stratified ejecta: the origin of flares in GRB afterglows

NASA Astrophysics Data System (ADS)

Lamberts, A.; Daigne, F.

2018-02-01

The X-ray light curves of the early afterglow phase from gamma-ray bursts (GRBs) present a puzzling variability, including flares. The origin of these flares is still debated, and often associated with a late activity of the central engine. We discuss an alternative scenario where the central engine remains short-lived and flares are produced by the propagation of a long-lived reverse shock in a stratified ejecta. Here we focus on the hydrodynamics of the shock interactions. We perform one-dimensional ultrarelativistic hydrodynamic simulations with different initial internal structure in the GRB ejecta. We use them to extract bolometric light curves and compare with a previous study based on a simplified ballistic model. We find a good agreement between both approaches, with similar slopes and variability in the light curves, but identify several weaknesses in the ballistic model: the density is underestimated in the shocked regions, and more importantly, late shock reflections are not captured. With accurate dynamics provided by our hydrodynamic simulations, we confirm that internal shocks in the ejecta lead to the formation of dense shells. The interaction of the long-lived reverse shock with a dense shell then produces a fast and intense increase of the dissipated power. Assuming that the emission is due to the synchrotron radiation from shock-accelerated electrons, and that the external forward shock is radiatively inefficient, we find that this results in a bright flare in the X-ray light curve, with arrival times, shapes, and duration in agreement with the observed properties of X-ray flares in GRB afterglows.

Development of the genital ducts and external genitalia in the early human embryo.

PubMed

Sajjad, Yasmin

2010-10-01

The course of development of the human genital tract is undifferentiated to the 9th week of development. At this time two symmetrical paired ducts known as the mesonephric (MD) and paramesonephric ducts (PMD) are present, which together with the urogenital sinus provide the tissue sources for internal and external genital development. Normal differentiation of the bipotential external genitalia and reproductive ducts are dependent upon the presence or absence of certain hormones. Masculinization of the internal and external genitalia during fetal development depends on the existence of two discrete testicular hormones. Testosterone secreted from Leydig cells induces the differentiation of the mesonephric ducts into the epididymis, vasa deferentia and seminal vesicles, whereas anti-Müllerian hormone (AMH) produced by Sertoli cells induces the regression of the paramesonephric ducts. The absence of AMH action in early fetal life results in the formation of the fallopian tubes, uterus and upper third of the vagina. In some target tissues, testosterone is converted to dihydrotestosterone, which is responsible for the masculinization of the urogenital sinus and external genitalia. © 2010 The Author. Journal of Obstetrics and Gynaecology Research © 2010 Japan Society of Obstetrics and Gynecology.

Discrimination and externalizing problems among Moroccan- and Romanian-origin early adolescents in Italy: Moderating role of cultural orientations and impulse control.

PubMed

Miconi, Diana; Altoè, Gianmarco; Salcuni, Silvia; Di Riso, Daniela; Schiff, Sami; Moscardino, Ughetta

2018-05-24

Although discrimination is a common stressor in the everyday life of immigrant youth, individuals are not equally susceptible to its adverse effects. This cross-sectional study aimed to examine whether cultural orientation preferences and impulse control (IC) moderate the association between perceived discrimination and externalizing problems among Moroccan- and Romanian-origin early adolescents in Italy. The sample included 126 Moroccan and 126 Romanian youths (46% girls, 42% first-generation) aged 11-13 years and their parents. Perceived discrimination and cultural orientations were assessed using self-report questionnaires, while IC was evaluated via a computerized version of the Iowa Gambling Task. Externalizing behaviors were assessed via parental report. Cluster analysis identified separated, assimilated, and integrated early adolescents. Regression analyses revealed that when facing discrimination, youths who endorsed separation and exhibited low levels of IC were more vulnerable to externalizing problems. In contrast, among assimilated adolescents the discrimination-externalizing difficulties link was significant at high levels of IC. Furthermore, low levels of IC were associated with more externalizing problems for Romanian, but not for Moroccan early adolescents. Findings underscore the need to consider both cultural orientation processes and early adolescents' ability to control their impulses when developing interventions aimed to reduce discrimination-related problem behaviors in immigrant youth. Implications for theory and practice are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The Structure and Stability of Externalizing and Internalizing Problem Behavior during Early Adolescence

ERIC Educational Resources Information Center

Reitz, E.; Dekovic, M.; Meijer, A. M.

2005-01-01

The first aim of this study was to examine the structure of externalizing and internalizing problem behavior during early adolescence. Our second aim was to determine the stability of these problems for boys and for girls over time. A total of 650, 13-14-year-olds filled out (an expanded version of) the Youth Self-Report [YSR; "Manual for the…

Septic shock with no diagnosis at 24 hours: a pragmatic multicenter prospective cohort study.

PubMed

Contou, Damien; Roux, Damien; Jochmans, Sébastien; Coudroy, Rémi; Guérot, Emmanuel; Grimaldi, David; Ricome, Sylvie; Maury, Eric; Plantefève, Gaëtan; Mayaux, Julien; Mekontso Dessap, Armand; Brun-Buisson, Christian; de Prost, Nicolas

2016-11-06

The lack of a patent source of infection after 24 hours of management of shock considered septic is a common and disturbing scenario. We aimed to determine the prevalence and the causes of shock with no diagnosis 24 hours after its onset, and to compare the outcomes of patients with early-confirmed septic shock to those of others. We conducted a pragmatic, prospective, multicenter observational cohort study in ten intensive care units (ICU) in France. We included all consecutive patients admitted to the ICU with suspected septic shock defined by clinical suspicion of infection leading to antibiotic prescription plus acute circulatory failure requiring vasopressor support. A total of 508 patients were admitted with suspected septic shock. Among them, 374 (74 %) had early-confirmed septic shock, while the 134 others (26 %) had no source of infection identified nor microbiological documentation retrieved 24 hours after shock onset. Among these, 37/134 (28 %) had late-confirmed septic shock diagnosed after 24 hours, 59/134 (44 %) had a condition mimicking septic (septic shock mimicker, mainly related to adverse drug reactions, acute mesenteric ischemia and malignancies) and 38/134 (28 %) had shock of unknown origin by the end of the ICU stay. There were no differences between patients with early-confirmed septic shock and the remainder in ICU mortality and the median duration of ICU stay, of tracheal intubation and of vasopressor support. The multivariable Cox model showed that the risk of day-60 mortality did not differ between patients with or without early-confirmed septic shock. A sensitivity analysis was performed in the subgroup (n = 369/508) of patients meeting the Sepsis-3 definition criteria and displayed consistent results. One quarter of the patients admitted in the ICU with suspected septic shock had no infection identified 24 hours after its onset and almost half of them were eventually diagnosed with a septic shock mimicker. Outcome did not differ

Investigation of shock-acoustic-wave interaction in transonic flow

NASA Astrophysics Data System (ADS)

Feldhusen-Hoffmann, Antje; Statnikov, Vladimir; Klaas, Michael; Schröder, Wolfgang

2018-01-01

The buffet flow field around supercritical airfoils is dominated by self-sustained shock wave oscillations on the suction side of the wing. Theories assume that this unsteadiness is driven by an acoustic feedback loop of disturbances in the flow field downstream of the shock wave whose upstream propagating part is generated by acoustic waves. Therefore, in this study, first variations in the sound pressure level of the airfoil's trailing-edge noise during a buffet cycle, which force the shock wave to move upstream and downstream, are detected, and then, the sensitivity of the shock wave oscillation during buffet to external acoustic forcing is analyzed. Time-resolved standard and tomographic particle-image velocimetry (PIV) measurements are applied to investigate the transonic buffet flow field over a supercritical DRA 2303 airfoil. The freestream Mach number is M_{∞} = 0.73, the angle of attack is α = {3.5}°, and the chord-based Reynolds number is Re_c = 1.9× 10^6. The perturbed Lamb vector field, which describes the major acoustic source term of trailing-edge noise, is determined from the tomographic PIV data. Subsequently, the buffet flow field is disturbed by an artificially generated acoustic field, the acoustic intensity of which is comparable to the Lamb vector that is determined from the PIV data. The results confirm the hypothesis that buffet is driven by an acoustic feedback loop and show the shock wave oscillation to directly respond to external acoustic forcing. That is, the amplitude modulation frequency of the artificial acoustic perturbation determines the shock oscillation.

Maternal Warmth and Early Adolescents' Internalizing Symptoms and Externalizing Behavior: Mediation via Emotional Insecurity

ERIC Educational Resources Information Center

Alegre, Albert; Benson, Mark J.; Pérez-Escoda, Núria

2014-01-01

This study examines the relation between maternal warmth and the internalizing and externalizing problems of early adolescents, and the potential mediation of this relation by emotional insecurity. The hypotheses for the study derive from Cummings and Davies' theory of emotional security. The current study extends the theory to security processes…

Pharmacy Students' Retention of Knowledge and Skills Following Training in Automated External Defibrillator Use

PubMed Central

Dopp, Anna Legreid; Dopp, John M.; Vardeny, Orly; Sims, J. Jason

2010-01-01

Objectives To assess pharmacy students' retention of knowledge about appropriate automated external defibrillator use and counseling points following didactic training and simulated experience. Design Following a lecture on sudden cardiac arrest and automated external defibrillator use, second-year doctor of pharmacy (PharmD) students were assessed on their ability to perform basic life support and deliver a shock at baseline, 3 weeks, and 4 months. Students completed a questionnaire to evaluate recall of counseling points for laypeople/the public. Assessment Mean time to shock delivery at baseline was 74 ± 25 seconds, which improved significantly at 3 weeks (50 ± 17 seconds, p < 0.001) and was maintained at 4 months (47 ± 18 seconds, p < 0.001). Recall of all signs and symptoms of sudden cardiac arrest and automated external defibrillator counseling points was diminished after 4 months. Conclusion Pharmacy students can use automated external defibrillators to quickly deliver a shock and are able to retain this ability after 4 months. Refresher training/courses will be required to improve students' retention of automated external defibrillator counseling points to ensure their ability to deliver appropriate patient education. PMID:21045951

Differential susceptibility to discipline: the moderating effect of child temperament on the association between maternal discipline and early childhood externalizing problems.

PubMed

van Zeijl, Jantien; Mesman, Judi; Stolk, Mirjam N; Alink, Lenneke R A; van Ijzendoorn, Marinus H; Bakermans-Kranenburg, Marian J; Juffer, Femmie; Koot, Hans M

2007-12-01

This study investigated the interaction of child temperament and maternal discipline in the prediction of externalizing problems in early childhood. Interaction effects were evaluated in a sample of 227 one- to three-year-old children with relatively high externalizing problems scores on the Child Behavior Checklist/1 1/2-5. Child temperament was reported by the mothers, maternal discipline was observed in a laboratory session, and child outcome measures included both mother-reported externalizing problems and observed physical aggression. Results indicate that children with difficult temperaments are more susceptible to negative discipline (i.e., they showed more externalizing problems) as well as more susceptible to positive discipline (i.e., they showed fewer externalizing problems and less physical aggression), as compared with children with relatively easy temperaments. These findings provide empirical evidence for the differential susceptibility hypothesis and suggest directions for enhancing the effectiveness of interventions aimed at reducing early childhood externalizing problems.

Endo- vs. exogenous shocks and relaxation rates in book and music “sales”

NASA Astrophysics Data System (ADS)

Lambiotte, R.; Ausloos, M.

2006-04-01

In this paper, we analyse the response of music and book sales to an external field and a buyer herding. We distinguish endogenous and exogenous shocks. We focus on some case studies, whose data have been collected from ranking on amazon.com. We show that an ensemble of equivalent systems quantitatively respond in a same way to a similar “external shock”, indicating roads to universality features. In contrast to Sornette et al. [Phys. Rev. Lett. 93 (2004) 228701] who seemed to find power-law behaviours, in particular at long times, a law interpreted in terms of an epidemic activity, we observe that the relaxation process can be as well seen as an exponential one that saturates toward an asymptotic state, itself different from the pre-shock state. By studying an ensemble of 111 shocks, on books or records, we show that exogenous and endogenous shocks are discriminated by their short-time behaviour: the relaxation time seems to be twice shorter in endogenous shocks than in exogenous ones. We interpret the finding through a simple thermodynamic model with a dissipative force.

Developmental Changes in the Relations between Inhibitory Control and Externalizing Problems during Early Childhood

ERIC Educational Resources Information Center

Utendale, William T.; Hastings, Paul D.

2011-01-01

Deficits in executive function, and in particular, reduced capacity to inhibit a dominant action, are a risk factor for externalizing problems (EP). Inhibitory control (IC) develops in the later preschool and early childhood periods, such that IC might not regulate EP in toddlers and younger preschoolers. Aggression was observed during peer play…

Mediated Pathways from Maternal Depression and Early Parenting to Children's Executive Function and Externalizing Behaviour Problems

ERIC Educational Resources Information Center

Baker, Claire; Kuhn, Laura

2018-01-01

Structural equation models were used to examine pathways from maternal depression and early parenting to children's executive function (EF) and externalizing behaviours in the first nationally representative study to obtain direct assessments of children's kindergarten EF skills (i.e., the Early Childhood Longitudinal Study Kindergarten Class of…

Shock-induced CO2 loss from CaCO3: Implications for early planetary atmospheres

NASA Technical Reports Server (NTRS)

Lange, M. A.; Ahrens, T. J.

1984-01-01

Recovered samples from shock recovery experiments on single crystal calcite were subjected to thermogravimetric analysis to determine the amount of post-shock CO2, the decarbonization interval and the activation energy, for the removal of remaining CO2 in shock-loaded calcite. Comparison of post-shock CO2 with that initially present determines shock-induced CO2 loss as a function of shock pressure. Incipient to complete CO2 loss occurs over a pressure range of approximately 10 to approximately 70 GPa. Optical and scanning electron microscopy reveal structural changes, which are related to the shock-loading. The occurrence of dark, diffuse areas, which can be resolved as highly vesicular areas as observed with a scanning electron microscope are interpreted as representing quenched partial melts, into which shock-released CO2 was injected. The experimental results are used to constrain models of shock-produced, primary CO2 atmospheres on the accreting terrestrial planets.

Lyman alpha radiation in external galaxies

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Mckee, Christopher F.

1990-01-01

The Ly alpha line of atomic hydrogen is often a luminous component of the radiation emitted by distant galaxies. Except for those galaxies which have a substantial central source of non-stellar ionizing radiation, most of the Ly alpha radiation emitted by galaxies is generated within regions of the interstellar medium which are photoionized by starlight. Conversely, much of the energy radiated by photoionized regions is carried by the Ly alpha line. Only hot, massive stars are capable of ionizing hydrogen in the interstellar medium which surrounds them, and because such stars are necessarily short-lived, Ly alpha emission traces regions of active star formation. Researchers argue that the strength of the Ly alpha emission observed from external galaxies may be used to estimate quantitatively the dust content of the emitting region, while the Ly alpha line profile is sensitive to the presence of shock waves. Interstellar dust particles and shock waves are intimately associated with the process of star formation in two senses. First, both dust particles and shock waves owe their existence to stellar activity; second, they may both serve as agents which facilitate the formation of stars, shocks by triggering gravitational instabilities in the interstellar gas that they compress, and dust by shielding star-forming molecular clouds from the ionizing and dissociative effects of external UV radiation. By using Ly alpha observations as a probe of the dust content in diffuse gas at high redshift, we might hope to learn about the earliest epochs of star formation.

Predicting Externalizing and Internalizing Behavior in Kindergarten: Examining the Buffering Role of Early Social Support

PubMed Central

Heberle, Amy E.; Krill, Sarah C.; Briggs-Gowan, Margaret J.; Carter, Alice S.

2014-01-01

Objective This study tested an ecological model predicting children’s behavior problems in kindergarten from risk and protective factors (parent psychological distress, parenting behavior, and social support) during early childhood. Method Study participants were 1161 socio-demographically diverse mother-child pairs who participated in a longitudinal birth cohort study. The predictor variables were collected at two separate time points and based on parent reports; children were an average of two years old at Time 1 and three years old at Time 2. The outcome measures were collected when children reached Kindergarten and were six years old on average. Results Our results show that early maternal psychological distress, mediated by sub-optimal parenting behavior, predicts children’s externalizing and internalizing behaviors in kindergarten. Moreover, early social support buffers the relations between psychological distress and later sub-optimal parenting behaviors and between sub-optimal parenting behavior and later depressive/withdrawn behavior. Conclusions Our findings have several implications for early intervention and prevention efforts. Of note, informal social support appears to play an important protective role in the development of externalizing and internalizing behavior problems, weakening the link between psychological distress and less optimal parenting behavior and between sub-optimal parenting behavior and children’s withdrawal/depression symptoms. Increasing social support may be a productive goal for family and community-level intervention. PMID:24697587

MODELING THE EARLY AFTERGLOW IN THE SHORT AND HARD GRB 090510

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

Fraija, N.; Lee, W. H.; Veres, P.

2016-11-01

The bright, short, and hard GRB 090510 was detected by all instruments aboard the Fermi and Swift satellites. The multiwavelength observations of this burst presented similar features to the Fermi -LAT-detected gamma-ray bursts. In the framework of the external shock model of early afterglow, a leptonic scenario that evolves in a homogeneous medium is proposed to revisit GRB 090510 and explain the multiwavelength light curve observations presented in this burst. These observations are consistent with the evolution of a jet before and after the jet break. The long-lasting LAT, X-ray, and optical fluxes are explained in the synchrotron emission frommore » the adiabatic forward shock. Synchrotron self-Compton emission from the reverse shock is consistent with the bright LAT peak provided that the progenitor environment is entrained with strong magnetic fields. It could provide compelling evidence of magnetic field amplification in the neutron star merger.« less

A novel electrochemical immunosensor based on PG for early screening of depression markers-heat shock protein 70.

PubMed

Sun, Bolu; Cai, Jinying; Li, Wuyan; Gou, Xiaodan; Gou, Yuqiang; Li, Dai; Hu, Fangdi

2018-07-15

In this study, a novel electrochemical immunosensor for early screening of depression markers-heat shock protein 70 (HSP70) was successfully developed based on the porous graphene (PG) with huge specific surface area and excellent structure. Benefiting from the strong adsorption and good bioactivity of PG which was initially prepared via a simple pyrolysis process, a variety of heat shock protein70 (HSP70) can be firmly loaded on the PG to construct the basic electrode (HSP70/PG/GCE)，which was characterized by the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the HSP70 fixed on the surface of basic electrode and the HSP70 in the samples can competitively combine with the horseradish peroxidase labeled human HSP 70 antibody (HRP-Strept-Biotin-Ab). As a result, it presented a negative correlation between the concentration of HSP70 in samples and the detection signal of the proposed electrochemical immunosensor (HRP-Strept-Biotin-Ab-HSP70/PG/GCE) in the test liquid. The application of PG with excellent electrical conductivity in construction of immunosensor remarkably improved the sensitivity of the immunosensor for detection of HSP70. The proposed immunosensor demonstrated a wide linear range of 0.0448 ~ 100 ng/mL with a low detection limit of 0.02 ng/mL at 3σ. Moreover, the proposed immunosensor could be applied for the sensitive and efficient detection of HSP70 in real samples with good precision, acceptable stability, reproducibility and satisfactory results. Therefore, the HSP70 immunosensor provides a novel and convenient method for early clinical screening of depression markers-heat shock protein 70. Copyright © 2018 Elsevier B.V. All rights reserved.

GRB 091208B: FIRST DETECTION OF THE OPTICAL POLARIZATION IN EARLY FORWARD SHOCK EMISSION OF A GAMMA-RAY BURST AFTERGLOW

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

Uehara, T.; Chiyonobu, S.; Fukazawa, Y.

We report that the optical polarization in the afterglow of GRB 091208B is measured at t = 149-706 s after the burst trigger, and the polarization degree is P = 10.4( {+-} 2.5%. The optical light curve at this time shows a power-law decay with index -0.75 {+-} 0.02, which is interpreted as the forward shock synchrotron emission, and thus this is the first detection of the early-time optical polarization in the forward shock (rather than that in the reverse shock reported by Steele et al.). This detection disfavors the afterglow model in which the magnetic fields in the emissionmore » region are random on the plasma skin depth scales, such as those amplified by the plasma instabilities, e.g., Weibel instability. We suggest that the fields are amplified by the magnetohydrodynamic instabilities, which would be tested by future observations of the temporal changes of the polarization degrees and angles for other bursts.« less

Genetic Vulnerability Interacts with Parenting and Early Care and Education to Predict Increasing Externalizing Behavior

ERIC Educational Resources Information Center

Lipscomb, Shannon T.; Laurent, Heidemarie; Neiderhiser, Jenae M.; Shaw, Daniel S.; Natsuaki, Misaki N.; Reiss, David; Leve, Leslie D.

2014-01-01

The current study examined interactions among genetic influences and children's early environments on the development of externalizing behaviors from 18 months to 6 years of age. Participants included 233 families linked through adoption (birth parents and adoptive families). Genetic influences were assessed by birth parent temperamental…

Dry and wet granular shock waves.

PubMed

Zaburdaev, V Yu; Herminghaus, S

2007-03-01

The formation of a shock wave in one-dimensional granular gases is considered, for both the dry and the wet cases, and the results are compared with the analytical shock wave solution in a sticky gas. Numerical simulations show that the behavior of the shock wave in both cases tends asymptotically to the sticky limit. In the inelastic gas (dry case) there is a very close correspondence to the sticky gas, with one big cluster growing in the center of the shock wave, and a step-like stationary velocity profile. In the wet case, the shock wave has a nonzero width which is marked by two symmetric heavy clusters performing breathing oscillations with slowly increasing amplitude. All three models have the same asymptotic energy dissipation law, which is important in the context of the free cooling scenario. For the early stage of the shock formation and asymptotic oscillations we provide analytical results as well.

Central venous pressure and shock index predict lack of hemodynamic response to volume expansion in septic shock: a prospective, observational study.

PubMed

Lanspa, Michael J; Brown, Samuel M; Hirshberg, Eliotte L; Jones, Jason P; Grissom, Colin K

2012-12-01

Volume expansion is a common therapeutic intervention in septic shock, although patient response to the intervention is difficult to predict. Central venous pressure (CVP) and shock index have been used independently to guide volume expansion, although their use is questionable. We hypothesize that a combination of these measurements will be useful. In a prospective, observational study, patients with early septic shock received 10-mL/kg volume expansion at their treating physician's discretion after brief initial resuscitation in the emergency department. Central venous pressure and shock index were measured before volume expansion interventions. Cardiac index was measured immediately before and after the volume expansion using transthoracic echocardiography. Hemodynamic response was defined as an increase in a cardiac index of 15% or greater. Thirty-four volume expansions were observed in 25 patients. A CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less individually had a good negative predictive value (83% and 88%, respectively). Of 34 volume expansions, the combination of both a high CVP and a low shock index was extremely unlikely to elicit hemodynamic response (negative predictive value, 93%; P = .02). Volume expansion in patients with early septic shock with a CVP of 8 mm Hg or greater and a shock index of 1 beat min(-1) mm Hg(-1) or less is unlikely to lead to an increase in cardiac index. Copyright © 2012 Elsevier Inc. All rights reserved.

Hepatic Shock Differential Diagnosis and Risk Factors: A Review Article.

PubMed

Soleimanpour, Hassan; Safari, Saeid; Rahmani, Farzad; Nejabatian, Arezu; Alavian, Seyed Moayed

2015-10-01

Liver as an important organ has a vital role in physiological processes in the body. Different causes can disrupt normal function of liver. Factors such as hypo-perfusion, hypoxemia, infections and some others can cause hepatic injury and hepatic shock. Published research resources from 2002 to May 2015 in some databases (PubMed, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Science direct, Cochrane library and Google scholar and Iranian search database like SID and Iranmedex) were investigated for the present study. Different causes can lead to hepatic shock. Most of these causes can be prevented by early resuscitation and treatment of underlying factors. Hepatic shock is detected in ill patients, especially those with hemodynamic disorders. It can be prevented by early treatment of underlying disease. There is no definite treatment for hepatic shock and should be managed conservatively. Hepatic shock in patients can increase the mortality rate.

Jet or Shock Breakout? The Low-Luminosity GRB 060218

NASA Astrophysics Data System (ADS)

Irwin, Christopher; Chevalier, Roger

2016-01-01

We consider a model for the long-duration, low-luminosity gamma-ray burst GRB 060218 that plausibly accounts for multiwavelength observations to day 20. The components of our model are: (1) a long-lived (tj ~ 3000 s) central engine and accompanying low-luminosity (Lj ~ 1045 erg s-1), mildly relativistic jet; (2) a low-mass (~ 10-2 Msun) envelope surrounding the progenitor star; and (3) a modest amount of dust (AV ~ 0.1) in the circumstellar or interstellar environment. Blackbody emission from the transparency radius in a low-power jet outflow can fit the prompt thermal X-ray emission, and the prompt nonthermal X-rays and γ-rays may be produced via Compton scattering of thermal photons from hot leptons in the jet interior or the external shocks. The later mildly relativistic phase of this outflow can produce the radio emission via synchrotron radiation from the forward shock. Meanwhile, interaction of the associated SN 2006aj with a circumstellar envelope extending to ~ 1013 cm can explain the early optical peak. The X-ray afterglow can be interpreted as a light echo of the prompt emission from dust at ~ 30 pc. Our model is a plausible alternative to that of Nakar, who recently proposed shock breakout of a jet smothered by an extended envelope as the source of prompt emission. Both our results and Nakar's suggest that ultra-long bursts such as GRB 060218 and GRB 100316D may originate from unusual progenitors with extended circumstellar envelopes, and that a jet is necessary to decouple the prompt high-energy emission from the supernova.

Jet or shock breakout? The low-luminosity GRB 060218

NASA Astrophysics Data System (ADS)

Irwin, Christopher M.; Chevalier, Roger A.

2016-08-01

We consider a model for the low-luminosity gamma-ray burst GRB 060218 that plausibly accounts for multiwavelength observations to day 20. The model components are: (1) a long-lived (tj ˜ 3000 s) central engine and accompanying low-luminosity (Lj ˜ 1047 erg s-1), mildly relativistic (γ ˜ 10) jet; (2) a low-mass (˜4 × 10-3 M⊙) envelope surrounding the progenitor star; and (3) a modest amount of dust (AV ˜ 0.1 mag) in the circumstellar or interstellar environment. Blackbody emission from the transparency radius in a low-power jet outflow can fit the prompt thermal X-ray emission, and the non-thermal X-rays and gamma-rays may be produced via Compton scattering of thermal photons from hot leptons in the jet interior or the external shocks. The later mildly relativistic phase of this outflow can produce the radio emission via synchrotron radiation from the forward shock. Meanwhile, interaction of the associated SN 2006aj with a circumstellar envelope extending to ˜1013 cm can explain the early optical emission. The X-ray afterglow can be interpreted as a light echo of the prompt emission from dust at ˜30 pc. Our model is a plausible alternative to that of Nakar, who recently proposed shock breakout of a jet smothered by an extended envelope as the source of prompt emission. Both our results and Nakar's suggest that bursts such as GRB 060218 may originate from unusual progenitors with extended circumstellar envelopes, and that a jet is necessary to decouple the prompt emission from the supernova.

Streptococcus agalactiae toxic shock-like syndrome: two case reports and review of the literature.

PubMed

Al Akhrass, Fadi; Abdallah, Lina; Berger, Steven; Hanna, Rami; Reynolds, Nina; Thompson, Shellie; Hallit, Rabih; Schlievert, Patrick M

2013-01-01

We present 2 patients with Streptococcus agalactiae toxic shock-like syndrome and review another 11 well-reported cases from the literature. Streptococcal toxic shock-like syndrome is a devastating illness with a high mortality rate, therefore we stress the importance of early supportive management, antimicrobial therapy, and surgical intervention. Toxic shock-like syndrome is likely to be underestimated in patients with invasive Streptococcus agalactiae infection who present with shock. Early diagnosis requires high suspicion of the illness, along with a thorough mucocutaneous examination. Streptococcus agalactiae produces uncharacterized pyrogenic toxins, which explains the ability of the organism to cause toxic shock-like syndrome.

Associations of Perceived Sibling and Parent-Child Relationship Quality with Internalizing and Externalizing Problems: Comparing Indian and Dutch Early Adolescents

ERIC Educational Resources Information Center

Buist, Kirsten L.; Verhoeven, Marjolein; Hoksbergen, René; ter Laak, Jan; Watve, Sujala; Paranjpe, Analpa

2017-01-01

The aims of the present study were (a) to examine whether Dutch and Indian early adolescents differ concerning sibling and parent-child relationship quality and externalizing and internalizing problems, and (b) to compare the associations between sibling and parent-child relationship quality and externalizing and internalizing problems for Indian…

Shock absorbency of factors in the shoe/heel interaction--with special focus on role of the heel pad.

PubMed

Jørgensen, U; Bojsen-Møller, F

1989-06-01

The heel pad acts as a shock absorber in walking and in heel-strike running. In some patients, a reduction of its shock-absorbing capacity has been connected to the development of overuse injuries. In this article, the shock absorption of the heel pad as well as external shock absorbers are studied. Individual variation and the effect of trauma and confinement on the heel pad were specifically investigated. Drop tests, imitating heel impacts, were performed on a force plate. The test specimens were cadaver heel pads (n = 10); the shoe sole component consisted of ethyl vinyl acetate (EVA) foam and Sorbothane inserts. The shock absorption was significantly greater in the heel pad than in the external shock absorbers. The mean heel pad shock absorption was 1.1 times for EVA foam and 2.1 times for Sorbothane. The shock absorption varied by as much as 100% between heel pads. Trauma caused a decrease in the heel pad shock absorbency (24%), whereas heel pad confinement increased the shock absorbency (49% in traumatized heel pads and 29.5% in nontraumatized heel pads). These findings provide a biomechanical rationale for the clinical observations of a correlation between heel pad shock absorbency loss and heel strike-dependent overuse injuries. To increase shock absorbency, confinement of the heel pad should be attempted in vivo.

Early and innovative interventions for severe sepsis and septic shock: taking advantage of a window of opportunity

PubMed Central

Rivers, Emanuel P.; McIntyre, Lauralyn; Morro, David C.; Rivers, Kandis K.

2005-01-01

The pathogenic, diagnostic and therapeutic landscape of sepsis is no longer confined to the intensive care unit: many patients from other portals of entry to care, both outside and within the hospital, progress to severe disease. Approaches that have led to improved outcomes with other diseases (e.g., acute myocardial infarction, stroke and trauma) can now be similarly applied to sepsis. Improved understanding of the pathogenesis of severe sepsis and septic shock has led to the development of new therapies that place importance on early identification and aggressive management. This review emphasizes approaches to the early recognition, diagnosis and therapeutic management of sepsis, giving the clinician the most contemporary and practical approaches with which to treat these patients. PMID:16247103

Dhofar 378 Martian shergottite: Evidence of early shock melting

NASA Astrophysics Data System (ADS)

Park, Jisun; Bogard, Donald D.; Mikouchi, Takashi; McKay, Gordon A.

2008-08-01

Shock heating of the Dhofar 378 (Dho 378) Martian shergottite produced melting, vesiculation, and flow of the plagioclase, which upon cooling recrystallized into complex textures. Heating experiments on the similar Zagami shergottite indicate that Dho 378 was shock heated to 1000-1100°C and was cooled at ~2.5°C/h. An 39Ar-40Ar analysis of Dho 378 plagioclase indicates different Ar diffusion domains and K/Ca ratios. The lower-temperature phase defines an Ar-Ar isochron age of 141 +/- 32 Ma. The higher-temperature phase released more 40Ar but does not define an age. The meteorite's thermal history was examined by constructing a generic model to compare cooling rates for objects of different sizes against fractional diffusion loss of Ar for different cooling times. Using gas diffusion parameter values measured for Dho 378, this model indicates that it is improbable that the major shock heating event occurred at the time that Dho 378 was ejected from Mars ~3 Ma ago. Rather, we suggest that the time of shock heating is probably given by its Ar-Ar age. For Dho 378 to cool sufficiently fast not to lose most of its 40Ar ~3 Ma ago would require it to have been ejected into space as an impossibly small object. Larger and more reasonable Mars ejection sizes indicate that Dho 378 should have lost most of its 40Ar. On the basis of plagioclase texture and Ar data, we suggest that a major impact event ~141 Ma ago melted Dho 378 plagioclase, degassed most of its 40Ar, and deposited it in crater ejecta to cool. A smaller and later impact ejected it into space ~3 Ma ago.

Early risk pathways to physical versus relational peer aggression: The interplay of externalizing behavior and corporal punishment varies by child sex.

PubMed

Zulauf, Courtney A; Sokolovsky, Alexander W; Grabell, Adam S; Olson, Sheryl L

2018-03-01

Children who aggress against their peers may use physical or relational forms, yet little research has looked at early childhood risk factors and characteristics that uniquely predict high levels of relational versus physical aggression in preadolescence. Accordingly, the main aim of our study was to link early corporal punishment and externalizing behavior to children's physical and relational peer aggression during preadolescence and to examine how these pathways differed by sex. Participants were 193, 3-year-old boys (39%) and girls who were reassessed following the transition to kindergarten (5.5 years) and preadolescence (10.5 years). A series of autoregressive, cross-lagged path analyses were conducted to examine the relationships between child externalizing problems and corporal punishment at ages 3 and 5.5 years, and their association with physical and relational aggression at age 10.5. Multiple group analysis was used to determine whether pathways differed by sex. Three developmental pathways were identified: (i) direct associations between stable childhood externalizing problems and later physical aggression; (ii) a direct pathway from early corporal punishment to preadolescent relational and physical peer aggression; and (iii) an indirect pathway from early corporal punishment to later physical aggression via continuing externalizing problems in middle childhood. Child sex moderated the nature of these pathways, as well as the direction of association between risk and outcome variables. These data advance our understanding of the etiology of distinct forms of peer aggression and highlight the potential for more efficacious prevention and intervention efforts in the early childhood years. © 2018 Wiley Periodicals, Inc.

Revisiting Shock Initiation Modeling of Homogeneous Explosives

NASA Astrophysics Data System (ADS)

Partom, Yehuda

2013-04-01

Shock initiation of homogeneous explosives has been a subject of research since the 1960s, with neat and sensitized nitromethane as the main materials for experiments. A shock initiation model of homogeneous explosives was established in the early 1960s. It involves a thermal explosion event at the shock entrance boundary, which develops into a superdetonation that overtakes the initial shock. In recent years, Sheffield and his group, using accurate experimental tools, were able to observe details of buildup of the superdetonation. There are many papers on modeling shock initiation of heterogeneous explosives, but there are only a few papers on modeling shock initiation of homogeneous explosives. In this article, bulk reaction reactive flow equations are used to model homogeneous shock initiation in an attempt to reproduce experimental data of Sheffield and his group. It was possible to reproduce the main features of the shock initiation process, including thermal explosion, superdetonation, input shock overtake, overdriven detonation after overtake, and the beginning of decay toward Chapman-Jouget (CJ) detonation. The time to overtake (TTO) as function of input pressure was also calculated and compared to the experimental TTO.

Hepatic Shock Differential Diagnosis and Risk Factors: A Review Article

PubMed Central

Soleimanpour, Hassan; Safari, Saeid; Rahmani, Farzad; Nejabatian, Arezu; Alavian, Seyed Moayed

2015-01-01

Context: Liver as an important organ has a vital role in physiological processes in the body. Different causes can disrupt normal function of liver. Factors such as hypo-perfusion, hypoxemia, infections and some others can cause hepatic injury and hepatic shock. Evidence Acquisition: Published research resources from 2002 to May 2015 in some databases (PubMed, Scopus, Index Copernicus, DOAJ, EBSCO-CINAHL, Science direct, Cochrane library and Google scholar and Iranian search database like SID and Iranmedex) were investigated for the present study. Results: Different causes can lead to hepatic shock. Most of these causes can be prevented by early resuscitation and treatment of underlying factors. Conclusions: Hepatic shock is detected in ill patients, especially those with hemodynamic disorders. It can be prevented by early treatment of underlying disease. There is no definite treatment for hepatic shock and should be managed conservatively. Hepatic shock in patients can increase the mortality rate. PMID:26587034

A randomized trial of protocol-based care for early septic shock.

PubMed

Yealy, Donald M; Kellum, John A; Huang, David T; Barnato, Amber E; Weissfeld, Lisa A; Pike, Francis; Terndrup, Thomas; Wang, Henry E; Hou, Peter C; LoVecchio, Frank; Filbin, Michael R; Shapiro, Nathan I; Angus, Derek C

2014-05-01

In a single-center study published more than a decade ago involving patients presenting to the emergency department with severe sepsis and septic shock, mortality was markedly lower among those who were treated according to a 6-hour protocol of early goal-directed therapy (EGDT), in which intravenous fluids, vasopressors, inotropes, and blood transfusions were adjusted to reach central hemodynamic targets, than among those receiving usual care. We conducted a trial to determine whether these findings were generalizable and whether all aspects of the protocol were necessary. In 31 emergency departments in the United States, we randomly assigned patients with septic shock to one of three groups for 6 hours of resuscitation: protocol-based EGDT; protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions; or usual care. The primary end point was 60-day in-hospital mortality. We tested sequentially whether protocol-based care (EGDT and standard-therapy groups combined) was superior to usual care and whether protocol-based EGDT was superior to protocol-based standard therapy. Secondary outcomes included longer-term mortality and the need for organ support. We enrolled 1341 patients, of whom 439 were randomly assigned to protocol-based EGDT, 446 to protocol-based standard therapy, and 456 to usual care. Resuscitation strategies differed significantly with respect to the monitoring of central venous pressure and oxygen and the use of intravenous fluids, vasopressors, inotropes, and blood transfusions. By 60 days, there were 92 deaths in the protocol-based EGDT group (21.0%), 81 in the protocol-based standard-therapy group (18.2%), and 86 in the usual-care group (18.9%) (relative risk with protocol-based therapy vs. usual care, 1.04; 95% confidence interval [CI], 0.82 to 1.31; P=0.83; relative risk with protocol-based EGDT vs. protocol-based standard therapy, 1.15; 95% CI, 0.88 to 1

Shock Transmission and Fatigue in Human Running.

PubMed

Verbitsky, Oleg; Mizrahi, Joseph; Voloshin, Arkady; Treiger, July; Isakov, Eli

1998-08-01

The goal of this research was to analyze the effects of fatigue on the shock waves generated by foot strike. Twenty-two subjects were instrumented with an externally attached, lightweight accelerometer placed over the tibial tuberosity. The subjects ran on a treadmill for 30 min at a speed near their anaerobic threshold. Fatigue was established when the end-tidal CO 2 pressure decreased. The results indicated that approximately half of the subjects reached the fatigue state toward the end of the test. Whenever fatigue occurred, the peak acceleration was found to increase. It was thus concluded that there is a clear association between fatigue and increased heel strike-induced shock waves. These results have a significant implication for the etiology of running injuries, since shock wave attenuation has been previously reported to play an important role in preventing such injuries.

Inconsistent shock advisories for monomorphic VT and Torsade de Pointes--A prospective experimental study on AEDs and defibrillators.

PubMed

Fitzgerald, Abi; Johnson, Meshell; Hirsch, Jan; Rich, Mary-Ann; Fidler, Richard

2015-07-01

Cardiovascular disease and sudden cardiac arrest are the leading causes of death in the United States. Early defibrillation is key to successful resuscitation for patients who experience shockable rhythms during a cardiac arrest. It is therefore vital that the shock advisory of AEDs (automated external defibrillators) or defibrillators in AED mode be reliable and appropriate. The goal of this study was to better understand the performance of multiple lay-rescuer and hospital professional defibrillators in AED mode in their analysis of ventricular arrhythmias. The measurable objectives of this study sought to quantify: 1. No shock advisory for sinus rhythms at any rate. 2. Recognition and shock advisory for ventricular fibrillation (VF). 3. Recognition and shock advisory for monomorphic ventricular tachycardia (VT). 4. Recognition and shock advisory for Torsades de Pointes (TdP). This is a prospective evaluation of two AEDs and four semi-automatic, hospital professional defibrillators. This study represents post-marketing evaluation of FDA approved devices. Each defibrillator was connected to multiple rhythm simulators and presented with simulated ECG waveforms 20 consecutive times at various rates when possible. All four defibrillators and both AEDs tested consistently recognized normal sinus rhythm (NSR) from all rhythm sources, and did not recommend a shock for NSR at any rate (from 80 to 220 bpm). All four defibrillators and both AEDs recognized VF from all rhythm sources tested and recommended a shock 100% of the time. Variations were found in the shock advisory rates among defibrillators when testing simulated VT heart rates at or below 150 bpm. One AED tested did not consistently advise a shock for monomorphic VT or TdP at any tested rate. Lay-rescuer AEDs and professional hospital defibrillators tested in AED mode did not reliably recommend a shock for sustained monomorphic VT or TdP at certain rates, despite the fact that it is a critical component of the

Moderators of Negative Peer Influence on Early Adolescent Externalizing Behaviors: Individual Behavior, Parenting, and School Connectedness

ERIC Educational Resources Information Center

Mrug, Sylvie; Windle, Michael

2009-01-01

This study examined the extent to which antisocial behavior, parenting, and school connectedness moderated the association between peer deviancy in preadolescence and externalizing problems in early adolescence. The participants included 500 boys and girls, most of them African Americans. Peer deviancy was measured with teacher reports of…

Early lactate clearance is associated with biomarkers of inflammation, coagulation, apoptosis, organ dysfunction and mortality in severe sepsis and septic shock

PubMed Central

2010-01-01

Background Lactate clearance, a surrogate for the magnitude and duration of global tissue hypoxia, is used diagnostically, therapeutically and prognostically. This study examined the association of early lactate clearance with selected inflammatory, coagulation, apoptosis response biomarkers and organ dysfunction scores in severe sepsis and septic shock. Methods Measurements of serum arterial lactate, biomarkers (interleukin-1 receptor antagonist, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-alpha, intercellular adhesion molecule-1, high mobility group box-1, D-Dimer and caspase-3), and organ dysfunction scores (Acute Physiology and Chronic Health Evaluation II, Simplified Acute Physiology Score II, Multiple Organ Dysfunction Score, and Sequential Organ Failure Assessment) were obtained in conjunction with a prospective, randomized study examining early goal-directed therapy in severe sepsis and septic shock patients presenting to the emergency department (ED). Lactate clearance was defined as the percent change in lactate levels after six hours from a baseline measurement in the ED. Results Two-hundred and twenty patients, age 65.0 +/- 17.1 years, were examined, with an overall lactate clearance of 35.5 +/- 43.1% and in-hospital mortality rate of 35.0%. Patients were divided into four quartiles of lactate clearance, -24.3 +/- 42.3, 30.1 +/- 7.5, 53.4 +/- 6.6, and 75.1 +/- 7.1%, respectively (p < 0.01). The mean levels of all biomarkers and organ dysfunction scores over 72 hours were significantly lower with higher lactate clearance quartiles (p < 0.01). There was a significant decreased in-hospital, 28-day, and 60-day mortality in the higher lactate clearance quartiles (p < 0.01). Conclusions Early lactate clearance as a surrogate for the resolution of global tissue hypoxia is significantly associated with decreased levels of biomarkers, improvement in organ dysfunction and outcome in severe sepsis and septic shock. PMID:20181046

Vulnerability to shocks in the global seafood trade network

NASA Astrophysics Data System (ADS)

Gephart, Jessica A.; Rovenskaya, Elena; Dieckmann, Ulf; Pace, Michael L.; Brännström, Åke

2016-03-01

Trade can allow countries to overcome local or regional losses (shocks) to their food supply, but reliance on international food trade also exposes countries to risks from external perturbations. Countries that are nutritionally or economically dependent on international trade of a commodity may be adversely affected by such shocks. While exposure to shocks has been studied in financial markets, communication networks, and some infrastructure systems, it has received less attention in food-trade networks. Here, we develop a forward shock-propagation model to quantify how trade flows are redistributed under a range of shock scenarios and assess the food-security outcomes by comparing changes in national fish supplies to indices of each country’s nutritional fish dependency. Shock propagation and distribution among regions are modeled on a network of historical bilateral seafood trade data from UN Comtrade using 205 reporting territories grouped into 18 regions. In our model exposure to shocks increases with total imports and the number of import partners. We find that Central and West Africa are the most vulnerable to shocks, with their vulnerability increasing when a willingness-to-pay proxy is included. These findings suggest that countries can reduce their overall vulnerability to shocks by reducing reliance on imports and diversifying food sources. As international seafood trade grows, identifying these types of potential risks and vulnerabilities is important to build a more resilient food system.

SNR-shock impact on star formation

NASA Astrophysics Data System (ADS)

Sasaki, M.; Dincel, B.

2016-06-01

While stars form out of cores of molecular clouds due to gravitational collapse of the clouds, external pressure caused by shock waves of stellar winds or supernovae are believed to be responsible for triggering star formation. However, since massive stars evolve fast and their supernova remnants (SNRs) can only be observed up to an age of around 10^5 years, SNRs found near star-forming regions have most likely resulted from the same generation of stars as the young stellar objects (YSOs). Shock waves of these SNRs might show interaction with the existing YSOs and change their nature. We study YSO candidates in Galactic SNRs CTB 109, IC 443 and HB21, which are known to show interaction with molecular clouds and have associated infrared emission. By photometric and spectroscopic studies of YSOs in the optical and the near-infrared, we aim to find clear observational evidences for an interaction of SNR-shocks with YSOs.

Quantification of heat shock protein mRNA expression in warm and cold anoxic turtles (Trachemys scripta) using an external RNA control for normalization.

PubMed

Stecyk, Jonathan A W; Couturier, Christine S; Fagernes, Cathrine E; Ellefsen, Stian; Nilsson, Göran E

2012-03-01

The mRNA expression of heat-shock protein 90 (HSP90) and heat-shock cognate 70 (HSC70) was examined in cardiac chambers and telencephalon of warm- (21°C) and cold-acclimated (5°C) turtles (Trachemys scripta) exposed to normoxia, prolonged anoxia or anoxia followed by reoxygenation. Additionally, the suitability of total RNA as well as mRNA from β-actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and cyclophilin A (PPIA) for normalizing gene expression data was assessed, as compared to the use of an external RNA control. Measurements of HSP90 and HSC70 mRNA expression revealed that anoxia and reoxygenation have tissue- and gene-specific effects. By and large, the alterations support previous investigations on HSP protein abundance in the anoxic turtle heart and brain, as well as the hypothesized roles of HSP90 and HSC70 during stress and non-stress conditions. However, more prominent was a substantially increased HSP90 and HSC70 mRNA expression in the cardiac chambers with cold acclimation. The finding provides support for the notion that cold temperature induces a number of adaptations in tissues of anoxia-tolerant vertebrates that precondition them for winter anoxia. β-actin, GAPDH and PPIA mRNA expression and total RNA also varied with oxygenation state and acclimation temperature in a tissue- and gene-specific manner, as well as among tissue types, thus disqualifying them as suitable for real-time RT-PCR normalization. Thus, the present data highlights the advantages of normalizing real-time RT-PCR data to an external RNA control, an approach that also allows inter-tissue and potentially inter-species comparisons of target gene expression. Copyright © 2011 Elsevier Inc. All rights reserved.

Magnetic Diagnostics on the Magnetized Shock Experiment (MSX)

NASA Astrophysics Data System (ADS)

Hutchinson, T. M.; Weber, T. E.; Boguski, J. C.; Intrator, T. P.; Smith, R. J.; Dunn, J. P.

2013-10-01

The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory was built to investigate the physics of high-Alfvénic, supercritical, magnetized shocks through the acceleration and subsequent stagnation of a Field Reversed Configuration (FRC) plasmoid against a magnetic mirror and/or plasma target. An array of high-bandwidth, multi-axis, robust, internal magnetic probes has been constructed to characterize flux compression ratios, instability formation, and turbulent macro-scale features of the post-shock plasma. The mirror magnet is mounted on a linear translation stage, providing a capability to axially move the shock layer through the probe field of view. An independent, external probe array also provides conventional information on the FRC shape, velocity, and total pressure during the formation and acceleration phases. Probe design, characterization, configuration, and initial results are presented. This work is supported by the DOE OFES and NNSA under LANS contract DE-AC52-06NA25369. LA-UR-13-25189.

Burnett-Cattaneo continuum theory for shock waves.

PubMed

Holian, Brad Lee; Mareschal, Michel; Ravelo, Ramon

2011-02-01

We model strong shock-wave propagation, both in the ideal gas and in the dense Lennard-Jones fluid, using a refinement of earlier work, which accounts for the cold compression in the early stages of the shock rise by a nonlinear, Burnett-like, strain-rate dependence of the thermal conductivity, and relaxation of kinetic-temperature components on the hot, compressed side of the shock front. The relaxation of the disequilibrium among the three components of the kinetic temperature, namely, the difference between the component in the direction of a planar shock wave and those in the transverse directions, particularly in the region near the shock front, is accomplished at a much more quantitative level by a rigorous application of the Cattaneo-Maxwell relaxation equation to a reference solution, namely, the steady shock-wave solution of linear Navier-Stokes-Fourier theory, along with the nonlinear Burnett heat-flux term. Our new continuum theory is in nearly quantitative agreement with nonequilibrium molecular-dynamics simulations under strong shock-wave conditions, using relaxation parameters obtained from the reference solution. ©2011 American Physical Society

A Morphological Analysis of Gamma-Ray Burst Early-optical Afterglows

NASA Astrophysics Data System (ADS)

Gao, He; Wang, Xiang-Gao; Mészáros, Peter; Zhang, Bing

2015-09-01

Within the framework of the external shock model of gamma-ray burst (GRB) afterglows, we perform a morphological analysis of the early-optical light curves to directly constrain model parameters. We define four morphological types, i.e., the reverse shock-dominated cases with/without the emergence of the forward shock peak (Type I/Type II), and the forward shock-dominated cases without/with νm crossing the band (Type III/IV). We systematically investigate all of the Swift GRBs that have optical detection earlier than 500 s and find 3/63 Type I bursts (4.8%), 12/63 Type II bursts (19.0%), 30/63 Type III bursts (47.6%), 8/63 Type IV bursts (12.7%), and 10/63 Type III/IV bursts (15.9%). We perform Monte Carlo simulations to constrain model parameters in order to reproduce the observations. We find that the favored value of the magnetic equipartition parameter in the forward shock ({ɛ }B{{f}}) ranges from 10-6 to 10-2, and the reverse-to-forward ratio of ɛB ({{R}}B) is about 100. The preferred electron equipartition parameter {ɛ }{{e}}{{r},{{f}}} value is 0.01, which is smaller than the commonly assumed value, e.g., 0.1. This could mitigate the so-called “efficiency problem” for the internal shock model, if ɛe during the prompt emission phase (in the internal shocks) is large (say, ˜0.1). The preferred {{R}}B value is in agreement with the results in previous works that indicate a moderately magnetized baryonic jet for GRBs.

Asymmetric Shock Wave Generation in a Microwave Rocket Using a Magnetic Field

NASA Astrophysics Data System (ADS)

Takahashi, Masayuki

2017-10-01

A plasma pattern is reproduced by coupling simulations between a particle-in- cell with Monte Carlo collisions model and a finite-difference time-domain simulation for an electromagnetic wave propagation when an external magnetic field is applied to the breakdown volume inside a microwave-rocket nozzle. The propagation speed and energy-absorption rate of the plasma are estimated based on the breakdown simulation, and these are utilized to reproduce shock wave propagation, which provides impulsive thrust for the microwave rocket. The shock wave propagation is numerically reproduced by solving the compressible Euler equation with an energy source of the microwave heating. The shock wave is asymmetrically generated inside the nozzle when the electron cyclotron resonance region has a lateral offset, which generates lateral and angular impulses for postural control of the vehicle. It is possible to develop an integrated device to maintain beaming ight of the microwave rocket, achieving both axial thrust improvement and postural control, by controlling the spatial distribution of the external magnetic field.

Timing and causes of death in septic shock.

PubMed

Daviaud, Fabrice; Grimaldi, David; Dechartres, Agnès; Charpentier, Julien; Geri, Guillaume; Marin, Nathalie; Chiche, Jean-Daniel; Cariou, Alain; Mira, Jean-Paul; Pène, Frédéric

2015-12-01

Most studies about septic shock report a crude mortality rate that neither distinguishes between early and late deaths nor addresses the direct causes of death. We herein aimed to determine the modalities of death in septic shock. This was a 6-year (2008-2013) monocenter retrospective study. All consecutive patients diagnosed for septic shock within the first 48 h of intensive care unit (ICU) admission were included. Early and late deaths were defined as occurring within or after 3 days following ICU admission, respectively. The main cause of death in the ICU was determined from medical files. A multinomial logistic regression analysis using the status alive as the reference category was performed to identify the prognostic factors associated with early and late deaths. Five hundred forty-three patients were included, with a mean age of 66 ± 15 years and a high proportion (67 %) of comorbidities. The in-ICU and in-hospital mortality rates were 37.2 and 45 %, respectively. Deaths occurred early for 78 (32 %) and later on for 166 (68 %) patients in the ICU (n = 124) or in the hospital (n = 42). Early deaths were mainly attributable to intractable multiple organ failure related to the primary infection (82 %) and to mesenteric ischemia (6.4 %). In-ICU late deaths were directly related to end-of-life decisions in 29 % of patients and otherwise mostly related to ICU-acquired complications, including nosocomial infections (20.4 %) and mesenteric ischemia (16.6 %). Independent determinants of early death were age, malignancy, diabetes mellitus, no pathogen identification, and initial severity. Among 3-day survivors, independent risk factors for late death were age, cirrhosis, no pathogen identification, and previous corticosteroid treatment. Our study provides a comprehensive assessment of septic shock-related deaths. Identification of risk factors of early and late deaths may determine differential prognostic patterns.

Point-of-care optical tool to detect early stage of hemorrhage and shock

NASA Astrophysics Data System (ADS)

Gurjar, Rajan S.; Riccardi, Suzannah L.; Johnson, Blair D.; Johnson, Christopher P.; Paradis, Norman A.; Joyner, Michael J.; Wolf, David E.

2014-02-01

There is a critical unmet clinical need for a device that can monitor and predict the onset of shock: hemorrhagic shock or bleeding to death, septic shock or systemic infection, and cardiogenic shock or blood flow and tissue oxygenation impairment due to heart attack. Together these represent 141 M patients per year. We have developed a monitor for shock based on measuring blood flow in peripheral (skin) capillary beds using diffuse correlation spectroscopy, a form of dynamic light scattering, and have demonstrated proof-of-principle both in pigs and humans. Our results show that skin blood flow measurement, either alone or in conjunction with other hemodynamic properties such as heart rate variability, pulse pressure variability, and tissue oxygenation, can meet this unmet need in a small self-contained patch-like device in conjunction with a hand-held processing unit. In this paper we describe and discuss the experimental work and the multivariate statistical analysis performed to demonstrate proof-of-principle of the concept.

Early afterglows in wind environments revisited

NASA Astrophysics Data System (ADS)

Zou, Y. C.; Wu, X. F.; Dai, Z. G.

2005-10-01

When a cold shell sweeps up the ambient medium, a forward shock and a reverse shock will form. We analyse the reverse-forward shocks in a wind environment, including their dynamics and emission. An early afterglow is emitted from the shocked shell, e.g. an optical flash may emerge. The reverse shock behaves differently in two approximations: the relativistic and Newtonian cases, which depend on the parameters, e.g. the initial Lorentz factor of the ejecta. If the initial Lorentz factor is much less than 114E1/453Δ-1/40,12A-1/4*,-1, the early reverse shock is Newtonian. This may take place for the wider of a two-component jet, an orphan afterglow caused by a low initial Lorentz factor and so on. The synchrotron self-absorption effect is significant especially for the Newtonian reverse shock case, as the absorption frequency νa is larger than the cooling frequency νc and the minimum synchrotron frequency νm for typical parameters. For the optical to X-ray band, the flux is nearly unchanged with time during the early period, which may be a diagnostic for the low initial Lorentz factor of the ejecta in a wind environment. We also investigate the early light curves with different wind densities and compare them with those in the interstellar medium model.

General relativistic study of astrophysical jets with internal shocks

NASA Astrophysics Data System (ADS)

Vyas, Mukesh K.; Chattopadhyay, Indranil

2017-08-01

We explore the possibility of the formation of steady internal shocks in jets around black holes. We consider a fluid described by a relativistic equation of state, flowing about the axis of symmetry (θ = 0) in a Schwarzschild metric. We use two models for the jet geometry: (I) a conical geometry and (II) a geometry with non-conical cross-section. A jet with conical geometry has a smooth flow, while the jet with non-conical cross-section undergoes multiple sonic points and even standing shock. The jet shock becomes stronger, as the shock location is situated farther from the central black hole. Jets with very high energy and very low energy do not harbour shocks, but jets with intermediate energies do harbour shocks. One advantage of these shocks, as opposed to shocks mediated by external medium, is that these shocks have no effect on the jet terminal speed, but may act as possible sites for particle acceleration. Typically, a jet with specific energy 1.8c2 will achieve a terminal speed of v∞ = 0.813c for jet with any geometry, where, c is the speed of light in vacuum. But for a jet of non-conical cross-section for which the length scale of the inner torus of the accretion disc is 40rg, then, in addition, a steady shock will form at rsh ˜ 7.5rg and compression ratio of R ˜ 2.7. Moreover, electron-proton jet seems to harbour the strongest shock. We will discuss possible consequences of such a scenario.

The Curious Events Leading to the Theory of Shock Waves

NASA Technical Reports Server (NTRS)

Salas, Manuel D.

2006-01-01

We review the history of the development of the modern theory of shock waves. Several attempts at an early-theory quickly collapsed for lack of foundations in mathematics and thermodynamics. It is not until the works of Rankine and later Hugoniot that a full theory is established. Rankine is the first to show that within the shock a non-adiabatic process must occur. Hugoniot showed that in the absence of viscosity and heat conduction conservation of energy implies conservation of entropy in smooth regions and a jump in entropy across a shock. Even after the theory is fully developed, old notions continue to pervade the literature well into the early part of the 20th Century.

Simulations of Supernova Shock Breakout

NASA Astrophysics Data System (ADS)

Frey, Lucille; Fryer, C. L.; Hungerford, A. L.

2009-01-01

Massive stars at the end of their lives release huge amounts of energy in supernova explosions which can be detected across cosmological distances. Even if prior observations exist, such distances make supernova progenitors difficult to identify. Very early observations of supernovae give us a rare view of these short-lived stars immediately before core collapse. Several recently observed X-ray and UV bursts associated with supernova have been interpreted as shock breakout observations. When the radiation-dominated shock wave from core collapse approaches the stellar surface, the optical depth of the plasma ahead of the shock decreases until the radiation can escape in a burst. If a dense wind is present, the shock breaks out beyond the stellar surface. Occurring days or weeks before the optical light from radioactive decay peaks, shock breakout radiation can be used to determine the radius of the progenitor star or its recent mass loss history. Whether the durations and spectra of the observed X-ray and UV bursts match those expected for shock breakout is currently being debated. A similar phenomenon would occur when the shockwave interacts with gas shells such as those ejected by luminous blue variable outbursts. Full radiation-hydrodynamics calculations are necessary to reproduce the behavior of the radiation-dominated shock and shock breakout. We use a radiation-hydrodynamics code with adaptive mesh refinement to follow the motion of the shock wave with high resolution. We run a suite of one dimensional simulations using binary and single progenitors with a range of mass loss histories, wind velocities and explosion energies. These simulations will better constrain the properties of the progenitor star and its environment that can be derived from shock breakout observations. This work was funded in part under the auspices of the U.S. Dept. of Energy, and supported by its contract W-7405-ENG-36 to Los Alamos National Laboratory.

On the interplay between cosmological shock waves and their environment

NASA Astrophysics Data System (ADS)

Martin-Alvarez, Sergio; Planelles, Susana; Quilis, Vicent

2017-05-01

Cosmological shock waves are tracers of the thermal history of the structures in the Universe. They play a crucial role in redistributing the energy within the cosmic structures and are also amongst the main ingredients of galaxy and galaxy cluster formation. Understanding this important function requires a proper description of the interplay between shocks and the different environments where they can be found. In this paper, an Adaptive Mesh Refinement (AMR) Eulerian cosmological simulation is analysed by means of a shock-finding algorithm that allows to generate shock wave maps. Based on the population of dark matter halos and on the distribution of density contrast in the simulation, we classify the shocks in five different environments. These range from galaxy clusters to voids. The shock distribution function and the shocks power spectrum are studied for these environments dynamics. We find that shock waves on different environments undergo different formation and evolution processes, showing as well different characteristics. We identify three different phases of formation, evolution and dissipation of these shock waves, and an intricate migration between distinct environments and scales. Shock waves initially form at external, low density regions and are merged and amplified through the collapse of structures. Shock waves and cosmic structures follow a parallel evolution. Later on, shocks start to detach from them and dissipate. We also find that most of the power that shock waves dissipate is found at scales of k ˜0.5 Mpc^{-1}, with a secondary peak at k ˜8 Mpc^{-1}. The evolution of the shocks power spectrum confirms that shock waves evolution is coupled and conditioned by their environment.

Parental Discipline and Externalizing Behavior Problems in Early Childhood: The Roles of Moral Regulation and Child Gender

ERIC Educational Resources Information Center

Kerr, David C.R.; Lopez, Nestor L.; Olson, Sheryl L.; Sameroff, Arnold J.

2004-01-01

We tested whether individual differences in a component of early conscience mediated relations between parental discipline and externalizing behavior problems in 238 3.5-year-olds. Parents contributed assessments of discipline practices and child moral regulation. Observations of children's behavioral restraint supplemented parental reports.…

A shock absorber model for structure-borne noise analyses

NASA Astrophysics Data System (ADS)

Benaziz, Marouane; Nacivet, Samuel; Thouverez, Fabrice

2015-08-01

Shock absorbers are often responsible for undesirable structure-borne noise in cars. The early numerical prediction of this noise in the automobile development process can save time and money and yet remains a challenge for industry. In this paper, a new approach to predicting shock absorber structure-borne noise is proposed; it consists in modelling the shock absorber and including the main nonlinear phenomena responsible for discontinuities in the response. The model set forth herein features: compressible fluid behaviour, nonlinear flow rate-pressure relations, valve mechanical equations and rubber mounts. The piston, base valve and complete shock absorber model are compared with experimental results. Sensitivity of the shock absorber response is evaluated and the most important parameters are classified. The response envelope is also computed. This shock absorber model is able to accurately reproduce local nonlinear phenomena and improves our state of knowledge on potential noise sources within the shock absorber.

Septic shock: desperately seeking treatment.

PubMed

Huet, Olivier; Chin-Dusting, Jaye P F

2014-01-01

Septic shock results from the dysregulation of the innate immune response following infection. Despite major advances in fundamental and clinical research, patients diagnosed with septic shock still have a poor prognostic outcome, with a mortality rate of up to 50%. Indeed, the reasons leading to septic shock are still poorly understood. First postulated 30 years ago, the general view of septic shock as an acute and overwhelming inflammatory response still prevails today. Recently, the fact that numerous clinical trials have failed to demonstrate any positive medical outcomes has caused us to question our fundamental understanding of this condition. New and sophisticated technologies now allow us to accurately profile the various stages and contributory components of the inflammatory response defining septic shock, and many studies now report a more complex inflammatory response, particularly during the early phase of sepsis. In addition, novel experimental approaches, using more clinically relevant animal models, to standardize and stratify research outcomes are now being argued for. In the present review, we discuss the most recent findings in relation to our understanding of the underlying mechanisms involved in septic shock, and highlight the attempts made to improve animal experimental models. We also review recent studies reporting promising results with two vastly different therapeutic approaches influencing the renin-angiotensin system and applying mesenchymal stem cells for clinical intervention.

Riata silicone defibrillation lead with normal electrical measures at routine ambulatory check: The role of high-voltage shock testing

PubMed Central

De Maria, Elia; Borghi, Ambra; Bonetti, Lorenzo; Fontana, Pier Luigi; Cappelli, Stefano

2016-01-01

AIM To describe our experience with shock testing for the evaluation of patients with Riata™ leads. METHODS Among 51 patients with normal baseline electrical parameters, 20 died during follow-up. Of the remaining 31 patients, 15 underwent the test: In 10 cases a defibrillation testing with ventricular fibrillation (VF) induction and in 5 cases a R-wave-synchronized shock (> 20 J, without inducing VF). The test was performed under sedation with Midazolam. RESULTS Twelve patients (80%) had a normal behavior during shock testing: In 8 cases induced VF was correctly detected and treated; in 4 cases of R-wave-synchronized shock electrical parameters remained stable and normal. Three patients (20%) failed the test. One patient with externalized conductors showed a sudden drop of high-voltage impedance (< 10 Ohm) after a 25 J R-wave-synchronized shock. Two other patients with externalized conductors, undergoing defibrillation testing, showed a short-circuit during shock delivery and the implantable cardioverter defibrillator was unable to interrupt VF. CONCLUSION In Riata™ leads the delivery of a low current during routine measurement of high-voltage impedance may not reveal a small short circuit, that can only be evident by attempting to deliver a true shock, either for spontaneous arrhythmias or in the context of a shock testing. PMID:27957252

The dynamics analysis of a ferrofluid shock absorber

NASA Astrophysics Data System (ADS)

Yao, Jie; Chang, Jianjun; Li, Decai; Yang, Xiaolong

2016-03-01

The paper presents a shock absorber using three magnets as the inertial mass. Movement of the inertial mass inside a cylindrical body filled with ferrofluid will lead to a viscous dissipation of the oscillating system energy. The influence of a dumbbell-like ferrofluid structure on the energy dissipation is considered and the magnetic restoring force is investigated by experiment and theoretical calculation. A theoretical model of the hydrodynamics and energy dissipation processes is developed, which includes the geometrical characteristics of the body, the fluid viscosity, and the external magnetic field. The theory predicts the experimental results well under some condition. The shock absorber can be used in spacecraft technology.

Cross-Reactivity between Chlamydia trachomatis Heat Shock Protein 10 and Early Pregnancy Factor

PubMed Central

Betsou, Fotini; Borrego, Maria José; Guillaume, Nicolas; Catry, Maria Anjos; Romão, Sandra; Machado-Caetano, J. A.; Sueur, Jean Marie; Mention, Jacques; Faille, Nicole; Orfila, Jeanne

2003-01-01

Chlamydia trachomatis heat shock protein 10 (Chsp10) is associated with chronic genital tract infection with C. trachomatis. Chsp10 is homologous to human chaperonin 10 (Cpn10) and early pregnancy factor (EPF), a form of human Cpn10 that is specifically secreted at the start of pregnancy. We investigated cross-reactions between serum anti-Chsp10 antibodies and anti-EPF antibodies in pregnant and nonpregnant patients. Pregnancy was found to be associated with the presence of anti-EPF antibodies, which are specifically induced in pregnant women with a history of C. trachomatis infection, and with the presence of serum anti-Chsp10 antibodies. We also found that infertility was associated with the presence of anti-Chsp10 and anti-EPF antibodies. The HLA class II haplotype DR8 DQ4 was associated with the presence of anti-Chsp10 antibodies but not of anti-EPF antibodies. PMID:12738647

Gamma-Ray Burst Spectral Indices: Evidence for Deceleration of Synchrotron Shocks

NASA Technical Reports Server (NTRS)

Preece, R. D.; Briggs, M. S.; Giblin, T.; Mallozzi, R. S.; Pendleton, G. N.; Paciesas, W. S.; Band, D. L.

2000-01-01

The current scenario for gamma-ray bursts (GRBs) involves internal shocks for the prompt GRB emission phase and external shocks for the afterglow phase. Assuming synchrotron emission from energetic shocked electrons. GRB spectra observed with a low-energy power-law spectral index greater than -2/3 (for positive photon number indices E(sup alpha) indicate a problem with this model. The remaining spectra can test the synchrotron shock model prediction that the emission from a single distribution of electrons, cooling rapidly, is responsible for both the low-energy and high-energy power-low portions of the spectra. We find that the inferred relationship between the two spectral indices of observed GRB spectra is inconsistent with the constraints from the model, posing another problem for the synchrotron shock emission model. To overcome this problem, we describe a model where the average of -1, rather than the value of -3/2 predicted for cooling electrons. Situations where this might arise have been discussed in other contexts, and involve deceleration of the internal shocks during the GRB phase.

The role of complement system in septic shock.

PubMed

Charchaflieh, Jean; Wei, Jiandong; Labaze, Georges; Hou, Yunfang Joan; Babarsh, Benjamin; Stutz, Helen; Lee, Haekyung; Worah, Samrat; Zhang, Ming

2012-01-01

Septic shock is a critical clinical condition with a high mortality rate. A better understanding of the underlying mechanisms is important to develop effective therapies. Basic and clinical studies suggest that activation of complements in the common cascade, for example, complement component 3 (C3) and C5, is involved in the development of septic shock. The involvement of three upstream complement pathways in septic shock is more complicated. Both the classical and alternative pathways appear to be activated in septic shock, but the alternative pathway may be activated earlier than the classical pathway. Activation of these two pathways is essential to clear endotoxin. Recent investigations have shed light on the role of lectin complement pathway in septic shock. Published reports suggest a protective role of mannose-binding lectin (MBL) against sepsis. Our preliminary study of MBL-associated serine protease-2 (MASP-2) in septic shock patients indicated that acute decrease of MASP-2 in the early phase of septic shock might correlate with in-hospital mortality. It is unknown whether excessive activation of these three upstream complement pathways may contribute to the detrimental effects in septic shock. This paper also discusses additional complement-related pathogenic mechanisms and intervention strategies for septic shock.

Trajectories of child externalizing problems between ages 3 and 10 years: Contributions of children's early effortful control, theory of mind, and parenting experiences.

PubMed

Olson, Sheryl L; Choe, Daniel Ewon; Sameroff, Arnold J

2017-10-01

Preventing problem behavior requires an understanding of earlier factors that are amenable to intervention. The main goals of our prospective longitudinal study were to trace trajectories of child externalizing behavior between ages 3 and 10 years, and to identify patterns of developmentally significant child and parenting risk factors that differentiated pathways of problem behavior. Participants were 218 3-year-old boys and girls who were reassessed following the transition to kindergarten (age 5-6 years) and during the late school-age years (age 10). Mothers contributed ratings of children's externalizing behavior at all three time points. Children's self-regulation abilities and theory of mind were assessed during a laboratory visit, and parenting risk (frequent corporal punishment and low maternal warmth) was assessed using interview-based and questionnaire measures. Four developmental trajectories of externalizing behavior yielded the best balance of parsimony and fit with our longitudinal data and latent class growth analysis. Most young children followed a pathway marked by relatively low levels of symptoms that continued to decrease across the school-age years. Atypical trajectories marked chronically high, increasing, and decreasing levels of externalizing problems across early and middle childhood. Three-year-old children with low levels of effortful control were far more likely to show the chronic pattern of elevated externalizing problems than changing or low patterns. Early parental corporal punishment and maternal warmth, respectively, differentiated preschoolers who showed increasing and decreasing patterns of problem behavior compared to the majority of children. The fact that children's poor effortful regulation skills predicted chronic early onset problems reinforces the need for early childhood screening and intervention services.

Systolic blood pressure variability in patients with early severe sepsis or septic shock: a prospective cohort study.

PubMed

Tang, Yi; Sorenson, Jeff; Lanspa, Michael; Grissom, Colin K; Mathews, V J; Brown, Samuel M

2017-06-17

Severe sepsis and septic shock are often lethal syndromes, in which the autonomic nervous system may fail to maintain adequate blood pressure. Heart rate variability has been associated with outcomes in sepsis. Whether systolic blood pressure (SBP) variability is associated with clinical outcomes in septic patients is unknown. The propose of this study is to determine whether variability in SBP correlates with vasopressor independence and mortality among septic patients. We prospectively studied patients with severe sepsis or septic shock, admitted to an intensive care unit (ICU) with an arterial catheter. We analyzed SBP variability on the first 5-min window immediately following ICU admission. We performed principal component analysis of multidimensional complexity, and used the first principal component (PC 1 ) as input for Firth logistic regression, controlling for mean systolic pressure (SBP) in the primary analyses, and Acute Physiology and Chronic Health Evaluation (APACHE) II score or NEE dose in the ancillary analyses. Prespecified outcomes were vasopressor independence at 24 h (primary), and 28-day mortality (secondary). We studied 51 patients, 51% of whom achieved vasopressor independence at 24 h. Ten percent died at 28 days. PC 1 represented 26% of the variance in complexity measures. PC 1 was not associated with vasopressor independence on Firth logistic regression (OR 1.04; 95% CI: 0.93-1.16; p = 0.54), but was associated with 28-day mortality (OR 1.16, 95% CI: 1.01-1.35, p = 0.040). Early SBP variability appears to be associated with 28-day mortality in patients with severe sepsis and septic shock.

Effect of Early Statin Treatment in Patients with Cardiogenic Shock Complicating Acute Myocardial Infarction

PubMed Central

Sim, Doo Sun; Cho, Kyung Hoon; Ahn, Youngkeun; Kim, Young Jo; Chae, Shung Chull; Hong, Taek Jong; Seong, In Whan; Chae, Jei Keon; Kim, Chong Jin; Cho, Myeong Chan; Rha, Seung-Woon; Bae, Jang Ho; Seung, Ki Bae; Park, Seung Jung

2013-01-01

Background and Objectives The benefit of early statin treatment following acute myocardial infarction (MI) complicated with cardiogenic shock (CS) has not been well studied. We sought to assess the effect of early statin therapy in patients with CS complicating acute MI. Subjects and Methods We studied 553 statin-naive patients with acute MI and CS (Killip class IV) who underwent revascularization therapy between November 2005 and January 2008 at 51 hospitals in the Korea Acute Myocardial Infarction Registry. Patients were divided into 2 groups: those who received statins during hospitalization (n=280) and those who did not (n=273). The influence of statin treatment on a 12-month clinical outcome was examined using a matched-pairs analysis (n=200 in each group) based on the propensity for receiving statin therapy during hospitalization. Results Before adjustment, patients receiving statin, compared to those not receiving statin, had a more favorable clinical profile, were less likely to suffer procedural complications, and more likely to receive adequate medical therapy. Patients receiving statin had lower unadjusted in-hospital mortality and composite rate of mortality, MI, and repeat revascularization at 12 months, which remained significantly lower after adjustment for patient risk, procedural characteristics, and treatment propensity. Conclusion In CS patients with acute MI undergoing revascularization therapy, early statin treatment initiated during hospitalization was associated with lower rates of in-hospital death and 12-month adverse cardiac events. PMID:23508129

Experimental study of subcritical laboratory magnetized collisionless shocks using a laser-driven magnetic piston

NASA Astrophysics Data System (ADS)

Schaeffer, D. B.; Everson, E. T.; Bondarenko, A. S.; Clark, S. E.; Constantin, C. G.; Winske, D.; Gekelman, W.; Niemann, C.

2015-11-01

Recent experiments at the University of California, Los Angeles have successfully generated subcritical magnetized collisionless shocks, allowing new laboratory studies of shock formation relevant to space shocks. The characteristics of these shocks are compared with new data in which no shock or a pre-shock formed. The results are consistent with theory and 2D hybrid simulations and indicate that the observed shock or shock-like structures can be organized into distinct regimes by coupling strength. With additional experiments on the early time parameters of the laser plasma utilizing Thomson scattering, spectroscopy, and fast-gate filtered imaging, these regimes are found to be in good agreement with theoretical shock formation criteria.

Inhibition of intraluminal pancreatic enzymes with nafamostat mesilate improves clinical outcomes after hemorrhagic shock in swine.

PubMed

Kim, Hubert D; Malinoski, Darren J; Borazjani, Boris; Patel, Madhukar S; Chen, Joseph; Slone, Johnathan; Nguyen, Xuan-Mai T; Steward, Earl; Schmid-Schonbein, Geert W; Hoyt, David B

2010-05-01

Recent studies suggest that intraluminal pancreatic enzymes play a major role in the initiation of the inflammatory cascade by the gut after hemorrhagic shock. Previous animal models have shown that the inhibition of enteral pancreatic enzymes with a serine protease inhibitor, nafamostat mesilate (NM), decreases leukocyte activation and transfusion requirements after hemorrhagic shock. The objective of this study was to determine whether enteroclysis with NM would improve the clinical outcomes in swine after hemorrhagic shock and intestinal hypoperfusion. Thirty-three male Yucatan minipigs weighing 25 kg to 30 kg underwent a controlled hemorrhage of 25 mL/kg with mesenteric clamp for further gut ischemia. Animals were allocated to three groups: (1) shock only (n = 15), (2) shock + enteroclysis with 100 mL/kg GoLYTELY (GL) as a carrier (n = 11), and (3) shock + enteroclysis with GL + 0.37 mmol/L NM (GL+NM, n = 7). Animals were resuscitated, recovered from anesthesia, observed for 3 days, and graded on a daily 4-point clinical scoring system. A score of 0 indicated a moribund state or early death, and a score of 4 indicated normal behavior. Pigs treated with GL + NM had significantly higher mean postoperative recovery scores (3.8 +/- 0.4, essentially normal behavior with no early deaths) compared with animals within the shock only and shock + GL groups (2.1 +/- 1 with one early death and 2.2 +/- 1.2 with two early deaths, respectively, analysis of variance p < 0.003). The inhibition of intraluminal pancreatic enzymes using enteroclysis with the serine protease inhibitor, NM, after hemorrhagic shock significantly improves the clinical outcome.

Sepsis and Septic Shock Strategies.

PubMed

Armstrong, Bracken A; Betzold, Richard D; May, Addison K

2017-12-01

Three therapeutic principles most substantially improve organ dysfunction and survival in sepsis: early, appropriate antimicrobial therapy; restoration of adequate cellular perfusion; timely source control. The new definitions of sepsis and septic shock reflect the inadequate sensitivity, specify, and lack of prognostication of systemic inflammatory response syndrome criteria. Sequential (sepsis-related) organ failure assessment more effectively prognosticates in sepsis and critical illness. Inadequate cellular perfusion accelerates injury and reestablishing perfusion limits injury. Multiple organ systems are affected by sepsis and septic shock and an evidence-based multipronged approach to systems-based therapy in critical illness results in improve outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

[Use of quantitative electroencephalogram in patients with septic shock].

PubMed

Ma, Yujie; Ouyang, Bin; Guan, Xiangdong

2016-01-19

To observe the quantitative electroencephalogram (qEEG) characteristics of the patients with septic shock in intensive care unit (ICU), and to find the early presence and severity of septic-associated encephalopathy (SAE) in these patients. During November 2014 to August 2015, 26 cases with septic shock were included from the ICU of the First Affiliated Hospital, Sun Yat-sen University.During the same period, 14 healthy volunteers were included as control. The brain function instrument was used to monitor the patients by the bed, placing leads as the internationally used 10-20 system, bipolar longitudinal F3-P3, F4-P4 four channels, and then consecutive clips of 5 minutes was chosen, using the average value of the clips, the amplitude integrated electroencephalogram (aEEG), relative frequency band energy, spectrum entropy, relative alpha ariability to carry out statistical analysis.And the qEEG features of septic shock patients with different Glasgow coma scale (GCS) levels were also analyzed. (1) 96% of the patients with septic shock had EEG abnormalities.Alpha frequency band energy, alpha ariability, aEEG amplitude, spectrum entropy decreased significantly (P<0.05=, while the delta frequency band energy significantly increased (P<0.05=. (2) aEEG amplitude decline appeared in 34% of patients with septic shock, and within the septic shock groups, amplitude decreased significantly (P<0.05= in patients with GCS under five. Patients with septic shock tends to have diffuse inhibition in EEG, and the inhibition degree can reflect cerebral lesion degree; changes of EEG frequency as early warning indicators of brain damage are sensitive, and the decline of amplitude often indicates critical injury.

The Early X-ray Emission From V382 Velorum (=Nove Vel 1999): An Internal Shock Model

NASA Technical Reports Server (NTRS)

Mukai, Koji; Ishida, Manabu

2000-01-01

We present the results of ASCA and RXTE observations of the early X-ray emission from the classical nova V382 Velorum. Its ASCA spectrum was hard (kT approximately 10 KeV) with a strong (10(exp 13)/sq cm) intrinsic absorption. In the subsequent RXTE data, the spectra became softer both due to a declining temperature and a diminishing column. We argue that this places the X-ray emission interior to the outermost ejecta produced by V382 Vel in 1999, and therefore must have been the result of a shock internal to the nova ejecta. The weakness of the Fe K.alpha lines probably indicates that the X-ray emitting plasmas are not in ionization equilibrium.

Relations between Parenting and Externalizing and Internalizing Problem Behaviour in Early Adolescence: Child Behaviour as Moderator and Predictor

ERIC Educational Resources Information Center

Reitz, E.; Dekovic, M.; Meijer, A. M.

2006-01-01

In this longitudinal study we investigated relations between parenting and externalizing and internalizing problem behaviour during early adolescence. First, we examined parenting effects on problem behaviour, including child behaviour as a moderator. Second, we examined child behaviour as predictor of parenting, also including moderator effects.…

Early goal-directed therapy using a physiological holistic view: the ANDROMEDA-SHOCK-a randomized controlled trial.

PubMed

Hernández, Glenn; Cavalcanti, Alexandre Biasi; Ospina-Tascón, Gustavo; Zampieri, Fernando Godinho; Dubin, Arnaldo; Hurtado, F Javier; Friedman, Gilberto; Castro, Ricardo; Alegría, Leyla; Cecconi, Maurizio; Teboul, Jean-Louis; Bakker, Jan

2018-04-23

Septic shock is a highly lethal condition. Early recognition of tissue hypoperfusion and its reversion are key factors for limiting progression to multiple organ dysfunction and death. Lactate-targeted resuscitation is the gold-standard under current guidelines, although it has several pitfalls including that non-hypoxic sources of lactate might predominate in an unknown proportion of patients. Peripheral perfusion-targeted resuscitation might provide a real-time response to increases in flow that could lead to a more timely decision to stop resuscitation, thus avoiding fluid overload and the risks of over-resuscitation. This article reports the rationale, study design and analysis plan of the ANDROMEDA-SHOCK Study. ANDROMEDA-SHOCK is a randomized controlled trial which aims to determine if a peripheral perfusion-targeted resuscitation is associated with lower 28-day mortality compared to a lactate-targeted resuscitation in patients with septic shock with less than 4 h of diagnosis. Both groups will be treated with the same sequential approach during the 8-hour study period pursuing normalization of capillary refill time versus normalization or a decrease of more than 20% of lactate every 2 h. The common protocol starts with fluid responsiveness assessment and fluid loading in responders, followed by a vasopressor and an inodilator test if necessary. The primary outcome is 28-day mortality, and the secondary outcomes are: free days of mechanical ventilation, renal replacement therapy and vasopressor support during the first 28 days after randomization; multiple organ dysfunction during the first 72 h after randomization; intensive care unit and hospital lengths of stay; and all-cause mortality at 90-day. A sample size of 422 patients was calculated to detect a 15% absolute reduction in mortality in the peripheral perfusion group with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. If peripheral perfusion

In vivo effect of shock-waves on the healing of fractured bone.

PubMed

Augat, P; Claes, L; Suger, G

1995-10-01

In a controlled animal experiment we attempted to clarify the question of whether there is a stimulating effect of extracorporeal shock-waves on the repair process of fractured long bones. As a fracture model we used an osteotomy in the diaphysis of the ovine tibia and an external fixation device. Shock-wave treatment at two levels of intensity and with four different numbers of applied shocks was performed with an electromagnetic acoustic source. Healing of the osteotomized bone was evaluated by biomechanical and radiological investigations on the whole bone as well as on bone sections from areas of the fracture gap and the periosteal fracture callus. We found a non-significant tendency to deterioration of the fracture healing with increasing shock-wave intensities. The study of treatment parameters led neither to significantly different biomechanical outcomes nor to altered radiological results in comparison to the untreated control group. RELEVANCE:--While we cannot comment upon the effectiveness of extracorporeal shock-waves in the delayed treatment of fractures or pseudarthrosis, our results suggest that shock-waves have no beneficial effect in acute fracture repair.

Propagation and dispersion of shock waves in magnetoelastic materials

NASA Astrophysics Data System (ADS)

Crum, R. S.; Domann, J. P.; Carman, G. P.; Gupta, V.

2017-12-01

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into an acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Finally, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.

Trajectories of pure and co-occurring internalizing and externalizing problems from age 2 to age 12: findings from the National Institute of Child Health and Human Development Study of Early Child Care.

PubMed

Fanti, Kostas A; Henrich, Christopher C

2010-09-01

How and why do internalizing and externalizing problems, psychopathological problems from different diagnostic classes representing separate forms of psychopathology, co-occur in children? We investigated the development of pure and co-occurring internalizing and externalizing problems from ages 2 to 12 with the use of latent class growth analysis. Furthermore, we examined how early childhood factors (temperament, cognitive functioning, maternal depression, and home environment) and early adolescent social and behavioral adjustment variables were related to differential trajectories of pure and co-occurring internalizing and externalizing problems. The sample (National Institute of Child Health and Human Development Study of Early Child Care) consisted of 1,232 children (52% male). Mother reports on the Child Behavior Checklist (Achenbach, 1991, 1992) were used to construct the trajectories of externalizing and internalizing problems. Analyses identified groups of children exhibiting pure and co-occurring internalizing and externalizing problems. Children exhibiting continuous externalizing or continuous co-occurring internalizing and externalizing problems across the 10-year period under investigation were more likely to (a) engage in risky behaviors, (b) be associated with deviant peers, (c) be rejected by peers, and (d) be asocial with peers at early adolescence. However, children exhibiting pure internalizing problems over time were only at higher risk for being asocial with peers as early adolescents. Moreover, the additive effects of individual and environmental early childhood risk factors influenced the development of chronic externalizing problems, although pure internalizing problems were uniquely influenced by maternal depression. Results also provided evidence for the concepts of equifinality and multifinality.

DebtRank: A Microscopic Foundation for Shock Propagation.

PubMed

Bardoscia, Marco; Battiston, Stefano; Caccioli, Fabio; Caldarelli, Guido

2015-01-01

The DebtRank algorithm has been increasingly investigated as a method to estimate the impact of shocks in financial networks, as it overcomes the limitations of the traditional default-cascade approaches. Here we formulate a dynamical "microscopic" theory of instability for financial networks by iterating balance sheet identities of individual banks and by assuming a simple rule for the transfer of shocks from borrowers to lenders. By doing so, we generalise the DebtRank formulation, both providing an interpretation of the effective dynamics in terms of basic accounting principles and preventing the underestimation of losses on certain network topologies. Depending on the structure of the interbank leverage matrix the dynamics is either stable, in which case the asymptotic state can be computed analytically, or unstable, meaning that at least one bank will default. We apply this framework to a dataset of the top listed European banks in the period 2008-2013. We find that network effects can generate an amplification of exogenous shocks of a factor ranging between three (in normal periods) and six (during the crisis) when we stress the system with a 0.5% shock on external (i.e. non-interbank) assets for all banks.

Ar-Ar Dating of Martian Meteorite, Dhofar 378: An Early Shock Event?

NASA Technical Reports Server (NTRS)

Park, J.; Bogard, D. D.

2006-01-01

Martian meteorite, Dhofar 378 (Dho378) is a basaltic shergottite from Oman, weighing 15 g, and possessing a black fusion crust. Chemical similarities between Dho378 and the Los Angeles 001 shergottite suggests that they might have derived from the same Mars locale. The plagioclase in other shergottites has been converted to maskelenite by shock, but Dho378 apparently experienced even more intense shock heating, estimated at 55-75 GPa. Dho378 feldspar (approximately 43 modal %) melted, partially flowed and vesiculated, and then partially recrystallized. Areas of feldspathic glass are appreciably enriched in K, whereas individual plagioclases show a range in the Or/An ratio of approximately 0.18-0.017. Radiometric dating of martian shergottites indicate variable formation times of 160-475 Myr, whereas cosmic ray exposure (CRE) ages of shergottites indicate most were ejected from Mars within the past few Myr. Most determined Ar-39-Ar-40 ages of shergottites appear older than other radiometric ages because of the presence of large amounts of martian atmosphere or interior Ar-40. Among all types of meteorites and returned lunar rocks, the impact event that initiated the CRE age very rarely reset the Ar-Ar age. This is because a minimum time and temperature is required to facilitate Ar diffusion loss. It is generally assumed that the shock-texture characteristics in martian meteorites were produced by the impact events that ejected the rocks from Mars, although the time of these shock events (as opposed to CRE ages) are not directly dated. Here we report Ar-39-Ar-40 dating of Dho378 plagioclase. We suggest that the determined age dates the intense shock heating event this meteorite experienced, but that it was not the impact that initiated the CRE age.

Coagulopathy and shock on admission is associated with mortality for children with traumatic injuries at combat support hospitals.

PubMed

Patregnani, Jason T; Borgman, Matthew A; Maegele, Marc; Wade, Charles E; Blackbourne, Lorne H; Spinella, Philip C

2012-05-01

In adults, early traumatic coagulopathy and shock are both common and independently associated with mortality. There are little data regarding both the incidence and association of early coagulopathy and shock on outcomes in pediatric patients with traumatic injuries. Our objective was to determine whether coagulopathy and shock on admission are independently associated with mortality in children with traumatic injuries. A retrospective review of the Joint Theater Trauma Registry from U.S. combat support hospitals in Iraq and Afghanistan from 2002 to 2009 was performed. Coagulopathy was defined as an international normalized ratio of ≥1.5 and shock as a base deficit of ≥6. Laboratory values were measured on admission. Primary outcome was inhospital mortality. Univariate analyses were performed on all admission variables followed by reverse stepwise multivariate logistic regression to determine independent associations. Combat support hospitals in Iraq and Afghanistan. Patients <18 yrs of age with Injury Severity Score, international normalized ratio, base deficit, and inhospital mortality were included. Of 1998 in the cohort, 744 (37%) had a complete set of data for analysis. None. The incidence of early coagulopathy and shock were 27% and 38.3% and associated with mortality of 22% and 16.8%, respectively. After multivariate logistic regression, early coagulopathy had an odds ratio of 2.2 (95% confidence interval 1.1-4.5) and early shock had an odds ratio of 3.0 (95% confidence interval 1.2-7.5) for mortality. Patients with coagulopathy and shock had an odds ratio of 3.8 (95% confidence interval 2.0-7.4) for mortality. In children with traumatic injuries treated at combat support hospitals, coagulopathy and shock on admission are common and independently associated with a high incidence of inhospital mortality. Future studies are needed to determine whether more rapid and accurate methods of measuring coagulopathy and shock as well as if early goal

External Versus Internal Pancreatic Duct Drainage for the Early Efficacy After Pancreaticoduodenectomy: A Retrospectively Comparative Study.

PubMed

Wang, Gang; Li, Le; Ma, Yuan; Qu, Feng-Zhi; Zhu, Hong; Lv, Jia-Chen; Jia, Yue-Hui; Wu, Lin-Feng; Sun, Bei

2016-08-01

To compare the early efficacy of external versus internal pancreatic duct drainage after pancreaticoduodenectomy (PD), providing clinical evidence for selecting the optimal approach to pancreatic duct drainage. The clinical data of 395 consecutive patients undergoing PD from 2006 to 2013 were analyzed retrospectively. All the patients were divided into external and internal drainage group. Intraoperative blood loss, surgery duration, postoperative hospitalization duration, mortality rate, PF, and other complications were compared between the two groups. The perioperative relative risk factors that might induce PF were analyzed. External drainage significantly reduced the incidences of post-PD PF, delayed gastric emptying, abdominal infection, bowel obstruction, overall complications, and shortened the healing time of PF (p < .05). The univariate analysis showed that the pancreatic duct drainage method, body mass index (BMI), preoperative serum bilirubin level, perioperative blood transfusion, pancreaticojejunostomy approach, pancreatic texture, pancreatic duct diameter, and primary disease differed markedly between the two groups (p < .05). A multivariate analysis revealed that BMI ≥ 25 kg/m(2), internal pancreatic duct drainage, pancreatic duct diameter <3 mm, soft pancreatic texture, and ampullary disease were independent risk factors for PF. External pancreatic duct drainage can effectively reduce the morbidity of PF and overall complications after PD.

Heat shock protein-containing exosomes in mid-trimester amniotic fluids.

PubMed

Asea, Alexzander; Jean-Pierre, Claudel; Kaur, Punit; Rao, Preethi; Linhares, Iara M; Skupski, Daniel; Witkin, Steven S

2008-10-01

Exosomes are multivesicular bodies formed by inverse membrane budding into the lumen of an endocytic compartment. Fusion with the plasma membrane leads to their release into the external milieu. The incorporation of heat shock proteins into exosomes has been associated with immune regulatory activity. We have examined whether heat shock protein-containing exosomes are present in mid-trimester amniotic fluid. Exosomes were isolated from mid-trimester amniotic fluids by sequential low-speed and high-speed centrifugation followed by sucrose density gradient centrifugation. Biochemical characterization included floatation pattern in sucrose gradients, acetylcholinesterase (AChE) activity and Western blot analysis for exosome-containing proteins. Exosomes were present in each of 23 amniotic fluids tested. They banded at a density of 1.17g/ml in sucrose gradients, were positive for AChE activity and contained tubulin, the inducible 72kDa heat shock protein, Hsp72 and the constitutively expressed heat shock protein, Hsc73; they were negative for calnexin. Exosome concentrations correlated positively with the number of pregnancies. Heat shock protein-containing exosomes are constituents of mid-trimester amniotic fluids and may contribute to immune regulation within the amniotic cavity.

Combined Measurement of Soluble ST2 and Amino-Terminal Pro-B-Type Natriuretic Peptide Provides Early Assessment of Severity in Cardiogenic Shock Complicating Acute Coronary Syndrome.

PubMed

Tolppanen, Heli; Rivas-Lasarte, Mercedes; Lassus, Johan; Sadoune, Malha; Gayat, Etienne; Pulkki, Kari; Arrigo, Mattia; Krastinova, Evguenia; Sionis, Alessandro; Parissis, John; Spinar, Jindrich; Januzzi, James; Harjola, Veli-Pekka; Mebazaa, Alexandre

2017-07-01

Mortality in cardiogenic shock complicating acute coronary syndrome is high, and objective risk stratification is needed for rational use of advanced therapies such as mechanical circulatory support. Traditionally, clinical variables have been used to judge risk in cardiogenic shock. The aim of this study was to assess the added value of serial measurement of soluble ST2 and amino-terminal pro-B-type natriuretic peptide to clinical parameters for risk stratification in cardiogenic shock. CardShock (www.clinicaltrials.gov NCT01374867) is a prospective European multinational study of cardiogenic shock. The main study introduced CardShock risk score, which is calculated from seven clinical variables at baseline, and was associated with short-term mortality. Nine tertiary care university hospitals. Patients with cardiogenic shock caused by acute coronary syndrome (n=145). In this substudy, plasma samples from the study patients were analyzed at eight time points during the ICU or cardiac care unit stay. Additional prognostic value of the biomarkers was assessed with incremental discrimination improvement. The combination of soluble ST2 and amino-terminal pro-B-type natriuretic peptide showed excellent discrimination for 30-day mortality (area under the curve, 0.77 at 12 hr up to 0.93 at 5-10 d after cardiogenic shock onset). At 12 hours, patients with both biomarkers elevated (soluble ST2, ≥ 500 ng/mL and amino-terminal pro-B-type natriuretic peptide, ≥ 4,500 ng/L) had higher 30-day mortality (79%) compared to those with one or neither biomarkers elevated (31% or 10%, respectively; p < 0.001). Combined measurement of soluble ST2 and amino-terminal pro-B-type natriuretic peptide at 12 hours added value to CardShock risk score, correctly reclassifying 11% of patients. The combination of results for soluble ST2 and amino-terminal pro-B-type natriuretic peptide provides early risk assessment beyond clinical variables in patients with acute coronary syndrome

ACTIVATION OF COMMON ANTIVIRAL PATHWAYS CAN POTENTIATE INFLAMMATORY RESPONSES TO SEPTIC SHOCK

PubMed Central

Doughty, Lesley A.; Carlton, Stacey; Galen, Benjamin; Cooma-Ramberan, Indranie; Chung, Chung-Shiang; Ayala, Alfred

2006-01-01

Induction of the antiviral cytokine interferon α/β (IFN-α/β) is common in many viral infections. The impact of ongoing antiviral responses on subsequent bacterial infection is not well understood. In human disease, bacterial superinfection complicating a viral infection can result in significant morbidity and mortality. We injected mice with polyinosinic-polycytidylic (PIC) acid, a TLR3 ligand and known IFN-α/β inducer as well as nuclear factor κB (NF-κB) activator to simulate very early antiviral pathways. We then challenged mice with an in vivo septic shock model characterized by slowly evolving bacterial infection to simulate bacterial superinfection early during a viral infection. Our data demonstrated robust induction of IFN-α in serum within 24 h of PIC injection with IFN-α/β–dependent major histocompatibility antigen class II up-regulation on peritoneal macrophages. PIC pretreatment before septic shock resulted in augmented tumor necrosis factor alpha and interleukins 6 and 10 and heightened lethality compared with septic shock alone. Intact IFN-α/β signaling was necessary for augmentation of the inflammatory response to in vivo septic shock and to both TLR2 and TLR4 agonists in vitro. To assess the NF-κB contribution to PIC-modulated inflammatory responses to septic shock, we treated with parthenolide an NF-κB inhibitor before PIC and septic shock. Parthenolide did not inhibit IFN-α induction by PIC. Inhibition of NF-κB by parthenolide did reduce IFN-α–mediated potentiation of the cytokine response and lethality from septic shock. Our data demonstrate that pathways activated early during many viral infections can have a detrimental impact on the outcome of subsequent bacterial infection. These pathways may be critical to understanding the heightened morbidity and mortality from bacterial superinfection after viral infection in human disease. PMID:16878028

Deconstructing the externalizing spectrum: Growth patterns of overt aggression, covert aggression, oppositional behavior, impulsivity/inattention, and emotion dysregulation between school entry and early adolescence

PubMed Central

Olson, Sheryl L.; Sameroff, Arnold J.; Lansford, Jennifer E.; Sexton, Holly; Davis-Kean, Pamela; Bates, John E.; Pettit, Gregory S.; Dodge, Kenneth A.

2013-01-01

The purpose of this study was to determine whether five subcomponents of children's externalizing behavior showed distinctive patterns of long-term growth and predictive correlates. We examined growth in teachers' ratings of overt aggression, covert aggression, oppositional defiance, impulsivity/inattention, and emotion dysregulation across three developmental periods spanning kindergarten through Grade 8 (ages 5–13 years). We also determined whether three salient background characteristics, family socioeconomic status, child ethnicity, and child gender, differentially predicted growth in discrete categories of child externalizing symptoms across development. Participants were 543 kindergarten-age children (52% male, 81% European American, 17% African American) whose problem behaviors were rated by teachers each successive year of development through Grade 8. Latent growth curve analyses were performed for each component scale, contrasting with overall externalizing, in a piecewise fashion encompassing three developmental periods: kindergarten–Grade 2, Grades 3–5, and Grades 6–8. We found that most subconstructs of externalizing behavior increased significantly across the early school age period relative to middle childhood and early adolescence. However, overt aggression did not show early positive growth, and emotion dysregulation significantly increased across middle childhood. Advantages of using subscales were most clear in relation to illustrating different growth functions between the discrete developmental periods. Moreover, growth in some discrete subcomponents was differentially associated with variations in family socioeconomic status and ethnicity. Our findings strongly affirmed the necessity of adopting a developmental approach to the analysis of growth in children's externalizing behavior and provided unique data concerning similarities and differences in growth between subconstructs of child and adolescent externalizing behavior. PMID

Inaccurate treatment decisions of automated external defibrillators used by emergency medical services personnel: incidence, cause and impact on outcome.

PubMed

Calle, Paul A; Mpotos, Nicolas; Calle, Simon P; Monsieurs, Koenraad G

2015-03-01

The rhythm analysis algorithm (RAA) of automated external defibrillators (AEDs) may be deceived by many factors. In this observational study we assessed RAA accuracy in prehospital interventions. For every rhythm analysis judged to be inaccurate, we looked for causal factors and estimated the impact on outcome. In 135 consecutive patients, two physicians reviewed 837 rhythm analyses independently. When they disagreed, a third physician made the final decision. Among 148 shockable episodes, 23 (16%) were not recognized by the RAA due to external artifacts (n=7), fine ventricular fibrillation (VF; n=7), RAA error without external artifacts (n=4) or a combination of factors (n=5). In six cases the omitted/delayed shock was judged to be of clinical relevance: survival with some neurological deficit (n=4), death without regaining consciousness (n=1) and no restoration of spontaneous circulation (n=1). In 689 non-shockable episodes, the RAA decided "shockable" 25 times (4%). This wrongful decision was due to external artifacts (n=9), a concurrent shock of an internal cardioverter defibrillator (n=1), RAA error without external artifacts (n=13) or a combination of factors (n=2). Fifteen spurious shocks were delivered. As these non-shockable rhythms did not deteriorate after the shock, we assumed that no significant harm was done. Up to 16% of shockable rhythms were not detected and 4% of non-shockable rhythms were interpreted as shockable. Therefore, all AED interventions should be reviewed. Feedback to caregivers may avoid future deleterious interactions with the AED, whereas AED manufacturers may use this information to improve RAA accuracy. This approach may improve the outcome of some VF patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Differential susceptibility to environmental influences: the role of early temperament and parenting in the development of externalizing problems.

PubMed

Pitzer, Martina; Jennen-Steinmetz, Christine; Esser, Guenter; Schmidt, Martin H; Laucht, Manfred

2011-01-01

A difficult or undercontrolled temperament, as well as harsh parental discipline or a lack of warmth, has long been regarded as risk factors for the development of externalizing problems. In addition, it has been suggested that children with difficult temperament are especially susceptible to rearing influences. We investigated the impact of early temperament and parenting and their interactions on externalizing behavior at school age. Participants were 148 boys and 160 girls from a prospective longitudinal study on a high-risk sample. At ages 3 months and 2 years, temperament was assessed by a highly structured parent interview and standardized behavioral observations. Maternal parenting was assessed by videotaped behavioral observation and a parent questionnaire. Externalizing problems at age 8 years were measured by the Child Behavior Checklist. Using hierarchical linear regression analyses, we found that externalizing problems were predicted by psychosocial adversity and poor self-control, whereas no main effect for restrictive parenting or maternal empathy was found. Fearful-inhibited boys were positively affected by empathic and sensitive parenting, whereas girls who were low in self-control and/or fearful developed less externalizing problems with restrictive parenting. Our results partly support the differential susceptibility hypothesis. In addition, they point toward gender-specific pathways in the development of externalizing problems. Copyright © 2011 Elsevier Inc. All rights reserved.

A survey of critical care nurses' practices and perceptions surrounding early intravenous antibiotic initiation during septic shock.

PubMed

Roberts, Russel J; Alhammad, Abdullah M; Crossley, Lindsay; Anketell, Eric; Wood, LeeAnn; Schumaker, Greg; Garpestad, Erik; Devlin, John W

2017-08-01

Delays in antibiotic administration after severe sepsis recognition increases mortality. While physician and pharmacy-related barriers to early antibiotic initiation have been well evaluated, those factors that affect the speed by which critical care nurses working in either the emergency department or the intensive care unit setting initiate antibiotic therapy remains poorly characterized. To evaluate the knowledge, practices and perceptions of critical care nurses regarding antibiotic initiation in patients with newly recognised septic shock. A validated survey was distributed to 122 critical care nurses at one 320-bed academic institution with a sepsis protocol advocating intravenous(IV) antibiotic initiation within 1hour of shock recognition. Among 100 (82%) critical care nurses responding, nearly all (98%) knew of the existence of the sepsis protocol. However, many critical care nurses stated they would optimise blood pressure [with either fluid (38%) or both fluid and a vasopressor (23%)] before antibiotic initiation. Communicated barriers to rapid antibiotic initiation included: excessive patient workload (74%), lack of awareness IV antibiotic(s) ordered (57%) or delivered (69%), need for administration of multiple non-antibiotic IV medications (54%) and no IV access (51%). Multiple nurse-related factors influence IV antibiotic(s) initiation speed and should be incorporated into sepsis quality improvement efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

Myocardial oxygen delivery after experimental hemorrhagic shock.

PubMed Central

Archie, J P; Mertz, W R

1978-01-01

The two components of myocardial oxygen delivery, coronary blood flow to capillaries and diffusion from capillaries to mitochondria, were studied in six dogs, (1) prior to shock, (2) after three hours of hemorrhage shock at a mean systemic arterial pressure of 40 torr, (3) after reinfusion of shed blood, and (4) during the irreversible late posttransfusion stage. There was a maldistribution of left ventricular coronary flow during late shock consistent with subendocardial ischemia. Cardiac performance was significantly impaired after resuscitation and all dogs became irreversible. Total and regional left ventricular coronary blood flow and myocardial oxygen delivery to capillaries were significantly greater than preshock values in (3) but not different from preshock values in (4). However, the myocardial oxygen diffusion area to distance ratio was significantly lower than preshock values in (3), and slightly lower in (4). These data suggest that myocardial oxygen diffusion may be impaired in the early post transfusion period, (3). Accordingly, the probable etiology of left ventricular dysfunction and possibly irreversibility after resuscitation from hemorrhagic shock is subendocardial ischemia during shock with either post-resuscitation impairment of myocardial oxygen diffusion, or in cellular oxygen utilization, or both. PMID:629622

Toxic Shock Syndrome Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) After Expander-Based Breast Reconstruction.

PubMed

Suga, Hirotaka; Shiraishi, Tomohiro; Takushima, Akihiko; Harii, Kiyonori

2016-01-01

Toxic shock syndrome is a rare but life-threatening complication after plastic surgery procedures. We experienced 2 cases of toxic shock syndrome after expander-based breast reconstruction caused by methicillin-resistant Staphylococcus aureus. The first patient took a severe clinical course due to the delayed diagnosis and treatment, and the second patient recovered rapidly after the early diagnosis and treatment based on our experience of the first case. Fever, rash, and gastrointestinal symptoms (diarrhea and/or vomiting) were characteristic and important for the early diagnosis of toxic shock syndrome. Considering the increased prevalence of methicillin-resistant Staphylococcus aureus, we should suspect methicillin-resistant Staphylococcus aureus in cases of toxic shock syndrome that occur postoperatively, and the empiric administration of vancomycin should be initiated in such cases.

Next generation maternal health: external shocks and health-system innovations.

PubMed

Kruk, Margaret E; Kujawski, Stephanie; Moyer, Cheryl A; Adanu, Richard M; Afsana, Kaosar; Cohen, Jessica; Glassman, Amanda; Labrique, Alain; Reddy, K Srinath; Yamey, Gavin

2016-11-05

In this Series we document the substantial progress in the reduction of maternal mortality and discuss the current state of science in reducing maternal mortality. However, maternal health is also powerfully influenced by the structures and resources of societies, communities, and health systems. We discuss the shocks from outside of the field of maternal health that will influence maternal survival including economic growth in low-income and middle-income countries, urbanisation, and health crises due to disease outbreaks, extreme weather, and conflict. Policy and technological innovations, such as universal health coverage, behavioural economics, mobile health, and the data revolution, are changing health systems and ushering in new approaches to affect the health of mothers. Research and policy will need to reflect the changing maternal health landscape. Copyright © 2016 Elsevier Ltd. All rights reserved.

Next generation maternal health: external shocks and health-system innovations

PubMed Central

Kruk, Margaret E; Kujawski, Stephanie; Moyer, Cheryl A; Adanu, Richard M; Afsana, Kaosar; Cohen, Jessica; Glassman, Amanda; Labrique, Alain; Reddy, K Srinath; Yamey, Gavin

2016-01-01

In this Series we document the substantial progress in the reduction of maternal mortality and discuss the current state of science in reducing maternal mortality. However, maternal health is also powerfully influenced by the structures and resources of societies, communities, and health systems. We discuss the shocks from outside of the field of maternal health that will influence maternal survival including economic growth in low-income and middle-income countries, urbanisation, and health crises due to disease outbreaks, extreme weather, and conflict. Policy and technological innovations, such as universal health coverage, behavioural economics, mobile health, and the data revolution, are changing health systems and ushering in new approaches to affect the health of mothers. Research and policy will need to reflect the changing maternal health landscape. PMID:27642020

Relations between Internalizing and Externalizing Problems in Early Childhood

ERIC Educational Resources Information Center

Stone, Lisanne L.; Otten, Roy; Engels, Rutger C. M. E.; Kuijpers, Rowella C. W. M.; Janssens, Jan M. A. M.

2015-01-01

Background: Childhood internalizing and externalizing problems are closely related and often co-occur. Directional models have been employed to test how these problems are related, while few studies have tested a third variables model. Objective: This study investigates whether internalizing and externalizing problems are reciprocally or…

The Observational Consequences of Proton-Generated Waves at Shocks

NASA Technical Reports Server (NTRS)

Reames, Donald V.

2000-01-01

In the largest solar energetic particle (SEP) events, acceleration takes place at shock waves driven out from the Sun by fast coronal mass ejections. Protons streaming away from strong shocks generate Alfven waves that trap particles in the acceleration region, limiting outflowing intensities but increasing the efficiency of acceleration to higher energies. Early in the events, with the shock still near the Sun, intensities at 1 AU are bounded and spectra are flattened at low energies. Elements with different charge-to-mass ratios, Q/A, differentially probe the wave spectra near shocks, producing abundance ratios that vary in space and time. An initial rise in He/H, while Fe/O declines, is a typical symptom of the non-Kolmogorov wave spectra in the largest events. Strong wave generation can cause cross-field scattering near the shock and unusually rapid reduction in anisotropies even far from the shock. At the highest energies, shock spectra steepen to form a "knee." For protons, this spectral knee can vary from approx. 10 MeV to approx. 1 GeV depending on shock conditions for wave growth. In one case, the location of the knee scales approximately as Q/A in the energy/nucleon spectra of other species.

Influence of exothermic chemical reactions on laser-induced shock waves.

PubMed

Gottfried, Jennifer L

2014-10-21

Differences in the excitation of non-energetic and energetic residues with a 900 mJ, 6 ns laser pulse (1064 nm) have been investigated. Emission from the laser-induced plasma of energetic materials (e.g. triaminotrinitrobenzene [TATB], cyclotrimethylene trinitramine [RDX], and hexanitrohexaazaisowurtzitane [CL-20]) is significantly reduced compared to non-energetic materials (e.g. sugar, melamine, and l-glutamine). Expansion of the resulting laser-induced shock wave into the air above the sample surface was imaged on a microsecond timescale with a high-speed camera recording multiple frames from each laser shot; the excitation of energetic materials produces larger heat-affected zones in the surrounding atmosphere (facilitating deflagration of particles ejected from the sample surface), results in the formation of additional shock fronts, and generates faster external shock front velocities (>750 m s(-1)) compared to non-energetic materials (550-600 m s(-1)). Non-explosive materials that undergo exothermic chemical reactions in air at high temperatures such as ammonium nitrate and magnesium sulfate produce shock velocities which exceed those of the inert materials but are less than those generated by the exothermic reactions of explosive materials (650-700 m s(-1)). The most powerful explosives produced the highest shock velocities. A comparison to several existing shock models demonstrated that no single model describes the shock propagation for both non-energetic and energetic materials. The influence of the exothermic chemical reactions initiated by the pulsed laser on the velocity of the laser-induced shock waves has thus been demonstrated for the first time.

Micro-Ramps for External Compression Low-Boom Inlets

NASA Technical Reports Server (NTRS)

Rybalko, Michael; Loth, Eric; Chima, Rodrick V.; Hirt, Stefanie M.; DeBonis, James R.

2010-01-01

The application of vortex generators for flow control in an external compression, axisymmetric, low-boom concept inlet was investigated using RANS simulations with three-dimensional (3-D), structured, chimera (overset) grids and the WIND-US code. The low-boom inlet design is based on previous scale model 1- by 1-ft wind tunnel tests and features a zero-angle cowl and relaxed isentropic compression centerbody spike, resulting in defocused oblique shocks and a weak terminating normal shock. Validation of the methodology was first performed for micro-ramps in supersonic flow on a flat plate with and without oblique shocks. For the inlet configuration, simulations with several types of vortex generators were conducted for positions both upstream and downstream of the terminating normal shock. The performance parameters included incompressible axisymmetric shape factor, separation area, inlet pressure recovery, and massflow ratio. The design of experiments (DOE) methodology was used to select device size and location, analyze the resulting data, and determine the optimal choice of device geometry. The optimum upstream configuration was found to substantially reduce the post-shock separation area but did not significantly impact recovery at the aerodynamic interface plane (AIP). Downstream device placement allowed for fuller boundary layer velocity profiles and reduced distortion. This resulted in an improved pressure recovery and massflow ratio at the AIP compared to the baseline solid-wall configuration.

Real-time Interplanetary Shock Prediction System

NASA Astrophysics Data System (ADS)

Vandegriff, J. D.; Ho, G. C.; Plauger, J. M.

2002-05-01

We are creating a system to predict the arrival times and maximum intensities of energetic storm particle (ESP) events at the earth using particle fluxes measured by the EPAM instrument aboard NASA's ACE spacecraft. Real-time flux measurements, consisting of 5 minute averages made available 24 hours per day by the NOAA Space Environment Center, are fed into algorithms looking for characteristic changes in flux, velocity dispersion, and anisotropy. These quantities typically show changes up to 3 hours before shock passage, and thus we expect our system to deliver enhanced probabilities for shock arrival with approximately the same lead time. Forecasting information will be made publicly available through http://sd-www.jhuapl.edu/ACE/EPAM/, the Johns Hopkins University Applied Physics Lab web site for the ACE/EPAM instrument. Early results on the training of our algorithms and comparisons with past shock data will be presented.

Music Preferences, Friendship, and Externalizing Behavior in Early Adolescence: A SIENA Examination of the Music Marker Theory Using the SNARE Study.

PubMed

Franken, Aart; Keijsers, Loes; Dijkstra, Jan Kornelis; Ter Bogt, Tom

2017-08-01

Music Marker Theory posits that music is relevant for the structuring of peer groups and that rock, urban, or dance music preferences relate to externalizing behavior. The present study tested these hypotheses, by investigating the role of music preference similarity in friendship selection and the development of externalizing behavior, while taking the effects of friends' externalizing behavior into account. Data were used from the first three waves of the SNARE (Social Network Analysis of Risk behavior in Early adolescence) study (N = 1144; 50% boys; M age  = 12.7; SD = 0.47), including students who entered the first-year of secondary school. Two hypotheses were tested. First, adolescents were expected to select friends based both on a similarity in externalizing behavior and music genre preference. Second, a preference for rock, urban, or dance, music types was expected to predict the development of externalizing behavior, even when taking friends' influence on externalizing behavior into account. Stochastic Actor-Based Modeling indicated that adolescents select their friends based on both externalizing behavior and highbrow music preference. Moreover, both friends' externalizing behavior and a preference for dance music predicted the development of externalizing behavior. Intervention programs might focus on adolescents with dance music preferences.

Shock-capturing parabolized Navier-Stokes model /SCIPVIS/ for the analysis of turbulent underexpanded jets

NASA Technical Reports Server (NTRS)

Dash, S. M.; Wolf, D. E.

1983-01-01

A new computational model, SCIPVIS, has been developed to predict the multiple-cell wave/shock structure in under or over-expanded turbulent jets. SCIPVIS solves the parabolized Navier-Stokes jet mixing equations utilizing a shock-capturing approach in supersonic regions of the jet and a pressure-split approach in subsonic regions. Turbulence processes are represented by the solution of compressibility corrected two-equation turbulence models. The formation of Mach discs in the jet and the interactive turbulent mixing process occurring behind the disc are handled in a detailed fashion. SCIPVIS presently analyzes jets exhausting into a quiescent or supersonic external stream for which a single-pass spatial marching solution can be obtained. The iterative coupling of SCIPVIS with a potential flow solver for the analysis of subsonic/transonic external streams is under development.

Propagation and dispersion of shock waves in magnetoelastic materials

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

Crum, R. S.; Domann, J. P.; Carman, G. P.

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less

Diagnostic Progress and Results on the Magnetized Shock Experiment

NASA Astrophysics Data System (ADS)

Smith, R. J.; Weber, T. E.

2015-11-01

The Magnetized Shock Experiment (MSX) at LANL is reliably producing Field Reversed Configuration (FRC) plasmas spanning peak densities of ~ 1021-23 m-3, combined Te +Ti of 10s-500eV and velocities of 100-300km/s as a means to producing a laboratory supercritical collision-less shock. Visible light images showing discontinuities indicative of shocks and jetting have been obtained on various targets: co-solenoid B field, a metal wall and counter-solenoidal B fields (FRC capture and reconnection). Two chord interferometry, external and internal magnetic probing are routinely employed and x-ray diagnostic capability has recently been added. The pulsed polarimetry technique is being deployed which can measure the local magnetic field using Lidar Thomson scattering. In addition, a fiber optic version of pulsed polarimetry using a new specialty fiber that enhances fiber backscatter with Fiber Bragg Gratings is being developed. Magnetic fields of order ~ 1T have been measured, however a new modified shock chamber geometry and recent machine modifications enabling operation at increased θ-coil voltage are expected to improve translation speed and hence stagnation pressures. Progress on these diagnostics and results will be presented. DOE support Grant No DE-SC00010559.

Propagation and dispersion of shock waves in magnetoelastic materials

DOE PAGES

Crum, R. S.; Domann, J. P.; Carman, G. P.; ...

2017-11-15

Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into anmore » acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Lastly, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.« less

Shock Structure: Application to the heliospheric termination shock and an interstellar shock

NASA Astrophysics Data System (ADS)

Mostafavi, P.; Zank, G. P.

2017-12-01

The structure of parallel and perpendicular shocks is often mediated by energetic particles. Here we describe shock structure when mediated by energetic particle heat flux and viscosity. We present a general theoretical model of shock mediation, which is then applied to Voyager 2 observations of the heliospheric termination shock (HTS) and Voyage 1 observations of a shock in very local interstellar medium (VLISM). Voyager 2 observations showed that the downstream HTS flow remained supersonic with respect to the thermal gas [Richardson et al., 2008]. Thus the thermal gas remains cold through the HTS and does not provide the dissipation to account for the deceleration of the supersonic solar wind. We show that PUIs are the primary dissipation mechanism and gain most of the solar wind kinetic energy in crossing the HTS. The interstellar shock observed by Voyager 1 [Burlaga et al., 2013] was extremely broad and so far there no theoretical explanation has been provided that describes the VLISM shock structure. Using the Chandrasekhar function, we show that the VLISM is collisional with respect to the thermal plasma and that electron and proton collisional mean free paths are very small. Thus, thermal collisionality should determine the structure of VLISM shocks. PUIs outside the heliosphere are generated by secondary charge exchange and contribute a very small pressure. Since PUIs and the dissipation associated with them cannot mediate the shock observed in the VLISM, we suggest that the thickness of the shock observed in the VLISM is due to collisional thermal gas dissipation.

DebtRank: A Microscopic Foundation for Shock Propagation

PubMed Central

Bardoscia, Marco; Battiston, Stefano; Caccioli, Fabio; Caldarelli, Guido

2015-01-01

The DebtRank algorithm has been increasingly investigated as a method to estimate the impact of shocks in financial networks, as it overcomes the limitations of the traditional default-cascade approaches. Here we formulate a dynamical “microscopic” theory of instability for financial networks by iterating balance sheet identities of individual banks and by assuming a simple rule for the transfer of shocks from borrowers to lenders. By doing so, we generalise the DebtRank formulation, both providing an interpretation of the effective dynamics in terms of basic accounting principles and preventing the underestimation of losses on certain network topologies. Depending on the structure of the interbank leverage matrix the dynamics is either stable, in which case the asymptotic state can be computed analytically, or unstable, meaning that at least one bank will default. We apply this framework to a dataset of the top listed European banks in the period 2008–2013. We find that network effects can generate an amplification of exogenous shocks of a factor ranging between three (in normal periods) and six (during the crisis) when we stress the system with a 0.5% shock on external (i.e. non-interbank) assets for all banks. PMID:26091013

[Ten years of early defibrillation: "Bochum against sudden cardiac death". Acceptance and critical analysis of using automated external defibrillators].

PubMed

Hanefeld, C; Kloppe, C; Breger, W; Kloppe, A; Mügge, A; Wiemer, M

2015-04-01

There is a comprehensive early defibrillation program in Bochum (Germany); since 2003 a total of 175 automated external defibrillators (AEDs) have been installed in urban areas by the city of Bochum and private companies. These were preferably installed in places with high foot traffic, e.g., public buildings, companies, and event/shopping centers. Approximately 15,000 laypeople who work in the vicinity of the AED locations were trained in the use of defibrillators and in basic resuscitation. In addition, rescue workers on fire trucks and medically trained personnel in physicians' medical practices were equipped as "first responders" with AEDs. After an initiation phase, all available information after each AED use since August 2004 has been collected by the project coordinator. During the period of data collection (August 2004 to August 2013), an AED was used in a total of 17 patients who had suffered sudden cardiac death (SCD) under the project in Bochum. Eleven patients had primary ventricular fibrillation (VF). Six of these survived without neurological deficit. In another 6 patients, a nondefibrillatable rhythm disorder was diagnosed. The AEDs are reliable and showed impeccable rhythm analysis before the instructions to provide any necessary shock. Compared to the number of existing units and an estimated number of 37-100 SCD/100,000, the use of the AEDs only 17 times appears relatively small. To improve the effectiveness of the AED program in Bochum, an analysis of the emergency service responses, which were necessary because of sudden circulatory collapse, is currently being performed. This will allow areas with an increased incidence of SCD to be identified and a plan for the strategic placement of AED and emergency services can be made.

Influences of the Driver and Ambient Medium Characteristics on the Formation of Shocks in the Solar Atmosphere

NASA Technical Reports Server (NTRS)

Nat, Gopalswamy; Hong, Xie; Seiji, Yashiro; Pertti, Makela; Sachiko, Akiyama

2010-01-01

Traveling interplanetary (IP) shocks were discovered in the early 1960s, but their solar origin has been controversial. Early research focused on solar flares as the source of the shocks, but when coronal mass ejections (CMEs) were discovered, it became clear that fast CMEs clearly can drive the shocks. Type II radio bursts are excellent signatures of shocks near the Sun. The close correspondence between type II radio bursts and solar energetic particles (SEPs) makes it clear that the same shock accelerates ions and electrons. A recent investigation involving a large number of IP shocks revealed that about 35% of IP shocks do not produce type II bursts or SEPs. Comparing these radio quiet (RQ) shocks with the radio loud (RL) ones revealed some interesting results: (1) there is no evidence for blast waves, in that all IP shocks can be attributed to CMEs, (2) a small fraction (20%) of RQ shocks is associated with ion enhancements at the shocks when they move past the observing spacecraft, (3) the primary difference between the RQ and RL shocks can be traced to the different kinematic properties of the associated CMEs and the variation of the characteristic speeds of the ambient medium, and (4) the shock properties measured at 1 AU are not too different for the RQ and RL cases due to the interaction of the shock driver with the IP medium that seems to erase the difference.

On the dynamics of a shock-bubble interaction

NASA Technical Reports Server (NTRS)

Quirk, James J.; Karni, Smadar

1994-01-01

We present a detailed numerical study of the interaction of a weak shock wave with an isolated cylindrical gas inhomogenity. Such interactions have been studied experimentally in an attempt to elucidate the mechanisms whereby shock waves propagating through random media enhance mixing. Our study concentrates on the early phases of the interaction process which are dominated by repeated refractions of acoustic fronts at the bubble interface. Specifically, we have reproduced two of the experiments performed by Haas and Sturtevant : M(sub s) = 1.22 planar shock wave, moving through air, impinges on a cylindrical bubble which contains either helium or Refrigerant 22. These flows are modelled using the two-dimensional, compressible Euler equations for a two component fluid (air-helium or air-Refrigerant 22). Although simulations of shock wave phenomena are now fairly commonplace, they are mostly restricted to single component flows. Unfortunately, multi-component extensions of successful single component schemes often suffer from spurious oscillations which are generated at material interfaces. Here we avoid such problems by employing a novel, nonconservative shock-capturing scheme. In addition, we have utilized a sophisticated adaptive mesh refinement algorithm which enables extremely high resolution simulations to be performed relatively cheaply. Thus we have been able to reproduce numerically all the intricate mechanisms that were observed experimentally (e.g., transitions from regular to irregular refraction, cusp formation and shock wave focusing, multi-shock and Mach shock structures, jet formation, etc.), and we can now present an updated description for the dynamics of a shock-bubble interaction.

Experimental evaluation of low-pass shock isolation performance of elastomers using frequency-based Kolsky bar analyses

DOE PAGES

Knight, Marlene E.; Sanborn, Brett; Song, Bo; ...

2017-01-26

Elastomeric materials are used as shock isolation materials in a variety of environments to dampen vibrations and/or absorb energy from external impact to minimize energy transfer between two objects or bodies. Some applications require the shock isolation materials to behave as a low-pass mechanical filter to mitigate the shock/impact at high frequencies but transmit the energy at low frequencies with minimal attenuation. To fulfill this requirement, a shock isolation material needs to be carefully evaluated and selected with proper experimental design, procedures, and analyses. In this study, a Kolsky bar was modified with precompression (up to 15.5 kN) and confinementmore » capabilities to evaluate low-pass shock isolation performance in terms of acceleration attenuation through a variety of elastomers. Also investigated were the effects of preload and specimen geometry on the low-pass shock isolation response.« less

Intermediate shocks in three-dimensional magnetohydrodynamic bow-shock flows with multiple interacting shock fronts

PubMed

De Sterck H; Poedts

2000-06-12

Simulation results of three-dimensional (3D) stationary magnetohydrodynamic (MHD) bow-shock flows around perfectly conducting spheres are presented. For strong upstream magnetic field a new complex bow-shock flow topology arises consisting of two consecutive interacting shock fronts. It is shown that the leading shock front contains a segment of intermediate 1-3 shock type. This is the first confirmation in 3D that intermediate shocks, which were believed to be unphysical for a long time, can be formed and can persist for small-dissipation MHD in a realistic flow configuration.

Risk of Fatal Cerebrovascular Accidents after External Beam Radiation Therapy for Early Stage Glottic Larynx Cancer

PubMed Central

Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O’Malley, Bert; Weinstein, Gregory S.; Bekelman, Justin E.

2013-01-01

Background This study compared the risk of fatal cerebrovascular accidents (CVA) in patients with early stage glottic larynx cancer receiving surgery or external beam radiation therapy (EBRT). Methods and Materials Using a competing risks survival analysis, we compared the risk of death due to CVA among patients with early stage glottic larynx cancer receiving surgery or EBRT in the SEER database. Results The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8 %; 95% CI 2.3%–3.4%) compared to surgery (1.5 %; 95% CI 0.8 %–2.3%, p= 0.024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted HR 1.75; 95% CI 1.04–2.96, p= 0.037). Conclusion Treatment of early stage glottic larynx cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. PMID:23595858

Effects of shock strength on shock turbulence interaction

NASA Technical Reports Server (NTRS)

Lee, Sangsan

1993-01-01

Direct numerical simulation (DNS) and linear analysis (LIA) of isotropic turbulence interacting with a shock wave are performed for several upstream shock normal Mach numbers (M(sub 1)). Turbulence kinetic energy (TKE) is amplified across the shock wave, but this amplification tends to saturate beyond M(sub 1) = 3.0. TKE amplification and Reynolds stress anisotropy obtained in DNS are consistent with LIA predictions. Rapid evolution of TKE immediate downstream of the shock wave persists for all shock strengths and is attributed to the transfer between kinetic and potential modes of turbulence energy through acoustic fluctuations. Changes in energy spectra and various length scales across the shock wave are predicted by LIA, which is consistent with DNS results. Most turbulence length scales decrease across the shock. Dissipation length scale (rho-bar q(exp 3) / epsilon), however, increases slightly for shock waves with M(sub 1) less than 1.65. Fluctuations in thermodynamic variables behind the shock wave stay nearly isentropic for M(sub 1) less than 1.2 and deviate significantly from isentropy for the stronger shock waves due to large entropy fluctuation generated through the interaction.

Uncovering the Secret of Shock Wave Lithotripsy

NASA Astrophysics Data System (ADS)

Zhong, P.

Shock wave lithotripsy (SWL) is an engineering innovation that has revolutionized the treatment of kidney stone disease since the early 1980s [1] - [3]. Today, SWL is the first-line therapy for millions of patients worldwide with renal and upper urinary stones [3, 4].

Preschool Externalizing Behavior Predicts Gender-Specific Variation in Adolescent Neural Structure

PubMed Central

Caldwell, Jessica Z. K.; Armstrong, Jeffrey M.; Hanson, Jamie L.; Sutterer, Matthew J.; Stodola, Diane E.; Koenigs, Michael; Kalin, Ned H.

2015-01-01

Dysfunction in the prefrontal cortex, amygdala, and hippocampus is believed to underlie the development of much psychopathology. However, to date only limited longitudinal data relate early behavior with neural structure later in life. Our objective was to examine the relationship of early life externalizing behavior with adolescent brain structure. We report here the first longitudinal study linking externalizing behavior during preschool to brain structure during adolescence. We examined the relationship of preschool externalizing behavior with amygdala, hippocampus, and prefrontal cortex volumes at age 15 years in a community sample of 76 adolescents followed longitudinally since their mothers’ pregnancy. A significant gender by externalizing behavior interaction revealed that males—but not females—with greater early childhood externalizing behavior had smaller amygdala volumes at adolescence (t = 2.33, p = .023). No significant results were found for the hippocampus or the prefrontal cortex. Greater early externalizing behavior also related to smaller volume of a cluster including the angular gyrus and tempoparietal junction across genders. Results were not attributable to the impact of preschool anxiety, preschool maternal stress, school-age internalizing or externalizing behaviors, or adolescent substance use. These findings demonstrate a novel, gender-specific relationship between early-childhood externalizing behavior and adolescent amygdala volume, as well as a cross-gender result for the angular gyrus and tempoparietal junction. PMID:25658357

Shock wave propagation in layered planetary embryos

NASA Astrophysics Data System (ADS)

Arkani-Hamed, Jafar; Ivanov, Boris A.

2014-05-01

The propagation of impact-induced shock wave inside a planetary embryo is investigated using the Hugoniot equations and a new scaling law, governing the particle velocity variations along a shock ray inside a spherical body. The scaling law is adopted to determine the impact heating of a growing embryo in its early stage when it is an undifferentiated and uniform body. The new scaling law, similar to other existing scaling laws, is not suitable for a large differentiated embryo consisting of a silicate mantle overlying an iron core. An algorithm is developed in this study on the basis of the ray theory in a spherically symmetric body which relates the shock parameters at the top of the core to those at the base of the mantle, thus enabling the adoption of scaling laws to estimate the impact heating of both the mantle and the core. The algorithm is applied to two embryo models: a simple two-layered model with a uniform mantle overlying a uniform core, and a model where the pre-shock density and acoustic velocity of the embryo are radially dependent. The former illustrates details of the particle velocity, shock pressure, and temperature increase behind the shock front in a 2D axisymmetric geometry. The latter provides a means to compare the results with those obtained by a hydrocode simulation. The agreement between the results of the two techniques in revealing the effects of the core-mantle boundary on the shock wave transmission across the boundary is encouraging.

Numerical Simulation Of Shock Response To Wall Changes In High Speed Intakes

NASA Astrophysics Data System (ADS)

Fincham, J.; Taylor, N. V.

2011-05-01

Hypersonic flight presents a number of challenges to the designer, one of which is the intake behaviour. Minimising drag requires careful positioning of the intake shock structure, while accurate understanding of the dynamic behaviour is required to allow minimisation of margins. In this paper, a two shock external compression intake derived from the Reaction Engines Limited SABRE engine is examined using inviscid axisymmetric CFD analysis to determine the response of the normal shockwave to axial motion of the intake centrebody. An approximately linear relationship between centrebody position and both the normal shock position and additive drag in steady flow is demonstrated. Initial results from an unsteady analysis are also given, which show complex behaviours may be triggered by rapid motion of the centrebody in response to control input.

Impact-shocked zircons: discovery of shock-induced textures reflecting increasing degrees of shock metamorphism

USGS Publications Warehouse

Bohor, B.F.; Betterton, W.J.; Krogh, T.E.

1993-01-01

Textural effects specifically characteristic of shock metamorphism in zircons from impact environments have not been reported previously. However, planar deformation features (PDF) due to shock metamorphism are well documented in quartz and other mineral grains from these same environments. An etching technique was developed that allows SEM visualization of PDF and other probable shock-induced textural features, such as granular (polycrystalline) texture, in zircons from a variety of impact shock environments. These textural features in shocked zircons from K/T boundary distal ejecta form a series related to increasing degrees of shock that should correlate with proportionate resetting of the UPb isotopic system. ?? 1993.

Impact-shocked zircons: Discovery of shock-induced textures reflecting increasing degrees of shock metamorphism

NASA Technical Reports Server (NTRS)

Bohor, B. F.; Betterton, W. J.; Krogh, T. E.

1993-01-01

Textural effects specifically characteristic of shock metamorphism in zircons from impact environments have not been reported previously. However, planar deformation features (PDF) due to shock metamorphism are well documented in quartz and other mineral grains from these same environments. An etching technique was developed that allows scanning electron microscope (SEM) visualization of PDF and other probable shock-induced textural features, such as granular (polycrystalline) texture, in zircons from a variety of impact shock environments. These textural features in shocked zircons from K/T boundary distal ejecta form a series related to increasing degrees of shock that should correlate with proportionate resetting of the U-Pb isotopic system.

Relative Shock Effects in Mixed Powders of Calcite, Gypsum, and Quartz: A Calibration Scheme from Shock Experiments

NASA Technical Reports Server (NTRS)

Bell, Mary S.

2009-01-01

The shock behavior of calcite and gypsum is important in understanding the Cretaceous/Tertiary event and other terrestrial impacts that contain evaporite sediments in their targets. Most interest focuses on issues of devolatilization to quantify the production of CO2 or SO2 to better understand their role in generating a temporary atmosphere and its effects on climate and biota [e.g., papers in 1,2,3,4]. Devolatilization of carbonate is also important because the dispersion and fragmentation of ejecta is strongly controlled by the expansion of large volumes of gas during the impact process as well [5,6]. Shock recovery experiments for calcite yield seemingly conflicting results: early experimental devolatilization studies [7,8,9] suggested that calcite was substantially outgassed at 30 GPa (> 50%). However, the recent petrographic work of [10,11,12] presented evidence that essentially intact calcite is recovered from 60 GPa experiments. [13] reported results of shock experiments on anhydrite, gypsum, and mixtures of those phases with silica. Their observations indicate little or no devolatilization of anhydrite shocked to 42 GPa and that the fraction of sulfur, by mass, that degassed is approx.10(exp -2) of theoretical prediction. In another (preliminary) report of shock experiments on calcite, anhydrite, and gypsum, [14] observe calcite recrystallization when shock loaded at 61 GPa, only intensive plastic deformation in anhydrite shock loaded at 63 GPa, and gypsum converted to anhydrite when shock loaded at 56 GPa. [15] shock loaded anhydrite and quartz to a peak pressure of 60 GPa. All of the quartz grains were trans-formed to glass and the platy anhydrite grains were completely pseudomorphed by small crystallized anhydrite grains. However, no evidence of interaction between the two phases could be observed and they suggest that recrystallization of anhydrite grains is the result of a solid state transformation. [16] reanalyzed the calcite and anhydrite shock

Shell shock, trauma, and the First World War: the making of a diagnosis and its histories.

PubMed

Loughran, Tracey

2012-01-01

During the First World War, thousands of soldiers were treated for "shell shock," a condition which encompassed a range of physical and psychological symptoms. Shell shock has most often been located within a "genealogy of trauma," and identified as an important marker in the gradual recognition of the psychological afflictions caused by combat. In recent years, shell shock has increasingly been viewed as a powerful emblem of the suffering of war. This article, which focuses on Britain, extends scholarly analyses which question characterizations of shell shock as an early form of post-traumatic stress disorder. It also considers some of the methodological problems raised by recasting shell shock as a wartime medical construction rather than an essentially timeless manifestation of trauma. It argues that shell shock must be analyzed as a diagnosis shaped by a specific set of contemporary concerns, knowledges, and practices. Such an analysis challenges accepted understandings of what shell shock "meant" in the First World War, and also offers new perspectives on the role of shell shock in shaping the emergence of psychology and psychiatry in the early part of the twentieth century. The article also considers what relation, if any, might exist between intellectual and other histories, literary approaches, and perceptions of trauma as timeless and unchanging.

Laser-shocked energetic materials with metal additives: evaluation of chemistry and detonation performance.

PubMed

Gottfried, Jennifer L; Bukowski, Eric J

2017-01-20

A focused, nanosecond-pulsed laser has been used to ablate, atomize, ionize, and excite milligram quantities of metal-doped energetic materials that undergo exothermic reactions in the laser-induced plasma. The subsequent shock wave expansion in the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The method enables the estimation of detonation velocities based on the measured laser-induced air-shock velocities and has previously been demonstrated for organic military explosives. Here, the LASEM technique has been extended to explosive formulations with metal additives. A comparison of the measured laser-induced air-shock velocities for TNT, RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by the thermochemical code CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time (<10  μs) participation of metal additives in detonation events. The LASEM results show that while Al is mostly inert at early times in the detonation event (confirmed from large-scale detonation testing), B is active-and reducing the amount of hydrogen present during the early chemical reactions increases the resulting estimated detonation velocities.

External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

PubMed

Hogan, T S

2012-10-01

Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

Preliminary vibration, acoustic, and shock design and test criteria for components on the Lightweight External Tank (LWT)

NASA Technical Reports Server (NTRS)

1981-01-01

The Space Shuttle LWT is divided into zones and subzones. Zones are designated primarily to assist in determining the applicable specifications. A subzone (general Specification) is available for use when the location of the component is known but component design and weight are not well defined. When the location, weight, and mounting configuration of the component are known, specifications for appropriate subzone weight ranges are available. Along with the specifications are vibration, acoustic, shock, transportation, handling, and acceptance test requirements and procedures. A method of selecting applicable vibration, acoustic, and shock specifications is presented.

Vasopressin compared with norepinephrine augments the decline of plasma cytokine levels in septic shock.

PubMed

Russell, James A; Fjell, Chris; Hsu, Joseph L; Lee, Terry; Boyd, John; Thair, Simone; Singer, Joel; Patterson, Andrew J; Walley, Keith R

2013-08-01

Changes in plasma cytokine levels may predict mortality, and therapies (vasopressin versus norepinephrine) could change plasma cytokine levels in early septic shock. Our hypotheses were that changes in plasma cytokine levels over 24 hours differ between survivors and nonsurvivors, and that there are different effects of vasopressin and norepinephrine on plasma cytokine levels in septic shock. We studied 394 patients in a randomized, controlled trial of vasopressin versus norepinephrine in septic shock. We used hierarchical clustering and principal components analysis of the baseline cytokine concentrations to subgroup cytokines; we then compared survivors to nonsurvivors (28 d) and compared vasopressin- versus norepinephrine-induced changes in cytokine levels over 24 hours. A total of 39 plasma cytokines were measured at baseline and at 24 hours. Hierarchical clustering and principal components analysis grouped cytokines similarly. Survivors (versus nonsurvivors) had greater decreases of overall cytokine levels (P < 0.001). Vasopressin decreased overall 24-hour cytokine concentration compared with norepinephrine (P = 0.037). In less severe septic shock, the difference in plasma cytokine reduction over 24 hours between survivors and nonsurvivors was less pronounced than that seen in more severe septic shock. Furthermore, vasopressin decreased interferon-inducible protein 10 and granulocyte colony-stimulating factor more than did norepinephrine in less severe septic shock, whereas vasopressin decreased granulocyte-macrophage colony-stimulating factor in patients who had more severe shock. Survivors of septic shock had greater decreases of cytokines, chemokines and growth factors in early septic shock. Vasopressin decreased 24-hour plasma cytokine levels more than did norepinephrine. The vasopressin-associated decrease of cytokines differed according to severity of shock. Clinical trial registered with www.controlled-trials.com (ISRCTN94845869).

[Group A streptococcus-induced toxic shock syndrome in pregnancy: a case report of cesarean section].

PubMed

Yamada, Kumiko; Fukuda, Taeko; Kimura, Maiko; Hagiya, Keiichi; Danmura, Masato; Nakayama, Shin; Ogura, Tsuyoshi; Tanaka, Makoto

2012-12-01

Group A streptococcus (GAS)-induced toxic shock syndrome (TSS) in pregnancy is rare, but its clinical course is fulminant. The mortality rates of mother and fetus are reported to be 58 and 66%, respectively. We report a case of GAS-TSS after cesarean section. A 38-year-old pregnant woman of 38 weeks gestation was admitted to our hospital because of vomiting, fever of 39 degrees C, and continuous abdominal pain with scanty genital bleeding. She had complained of sore throat several days before. One hour after admission, external fetal monitoring revealed periodic pulse deceleration to 90 x beats min(-1). The emergent cesarean section was performed under general anesthesia. Approximately 8 hours after the cesarean section, she developed coma, shock and respiratory insufficiency requiring intubation. Streptococcus pyogens were isolated from her blood sample and the patient met criteria for GAS-TSS. She was treated with antibiotics (penicillin and clindamycin), antithrombin III, recomodulin, catecholamins, and continuous hemodialysis with filtration of toxins. Although the patient recovered and was discharged on 63rd day, the infant died on postpartum day 4. Early recognition and intensive treatment for GAS is recommended in a late stage pregnancy with an episode of sore throat, vomiting, high fever, strong labor pain, and DIC signs.

Real-Time Control of the Embedded Waveform for External Defibrillation

DTIC Science & Technology

2001-10-25

independently from transthoracic electrical impedance changes during shock time. Keywords - External defibrillation, real-time control I. INTRODUCTION ...Additional such possibilities may be useful for development a new electrotherapy methods, as electrochemotherapy for cancer treatment [6]. II...Department, Moscow State Institute of Electronic Technology , Moscow, Russia Fig.1. High voltage delivery unit. Report Documentation Page Report Date 25

GRB 110530A: Peculiar Broad Bump and Delayed Plateau in Early Optical Afterglows

NASA Astrophysics Data System (ADS)

Zhong, Shu-Qing; Xin, Li-Ping; Liang, En-Wei; Wei, Jian-Yan; Urata, Yuji; Huang, Kui-Yun; Qiu, Yu-Lei; Deng, Can-Min; Wang, Yuan-Zhu; Deng, Jin-Song

2016-11-01

We report our very early optical observations of GRB 110530A and investigate its jet properties together with its X-ray afterglow data. A peculiar broad onset bump followed by a plateau is observed in its early R band afterglow light curve. The optical data in the other bands and the X-ray data are well consistent with the temporal feature of the R band light curve. Our joint spectral fits of the optical and X-ray data show that they are in the same regime, with a photon index of ∼1.70. The optical and X-ray afterglow light curves are well fitted with the standard external shock model by considering a delayed energy injection component. Based on our modeling results, we find that the radiative efficiency of the gamma-ray burst jet is ∼ 1 % and the magnetization parameter of the afterglow jet is \\lt 0.04 with a derived extremely low {ε }B (the ratio of shock energy to the magnetic field) of (1.64+/- 0.25)× {10}-6. These results indicate that the jet may be matter dominated. A discussion on delayed energy injection from the accretion of the late fall-back material of its pre-supernova star is also presented.

SN 1987 A: A Unique Laboratory for Shock Physics

NASA Technical Reports Server (NTRS)

Sonneborn, George

2012-01-01

Supernova 1987 A has given us an unprecedented view of the evolution of the explosion debris and its interaction with circumstellar matter. The outer supernova debris, now expanding with velocities approx.8000 km/s, encountered the relatively dense circumstellar ring formed by presupernova mass loss in the early 1990s. The shock interaction is manifested by UV-optical "hotspots", an expanding X-ray ring, an expanding ring of knotty non-thermal radio emission, and a ring of thermal IR emission from silicate dust Recent ultraviolet observations of the emissions from the reverse shock and the ring with the HST/COS reveal new details about the shock interaction. Lyman alpha emission from the reverse shock is much stronger than H alpha and they have different emission morphologies, pointing to different emission mechanisms. The reverse shock was detected for the first time in C IV 1550. The N V to C IV brightness ratio indicates the N/C abundance ratio in the expanding debris is about 100X solar, about 3X N/C in the inner ring.

Dispatcher assistance and automated external defibrillator performance among elders.

PubMed

Ecker, R; Rea, T D; Meischke, H; Schaeffer, S M; Kudenchuk, P; Eisenberg, M S

2001-10-01

Automated external defibrillators (AEDs) provide an opportunity to improve survival in out-of-hospital, ventricular fibrillation (VF) cardiac arrest by enabling laypersons not trained in rhythm recognition to deliver lifesaving therapy. The potential role of emergency dispatchers in the layperson use of AEDs is uncertain. This study was performed to examine whether dispatcher telephone assistance affected AED skill performance during a simulated VF cardiac arrest among a cohort of older adults. The hypothesis was that dispatcher assistance would increase the proportion who were able to correctly deliver a shock, but might require additional time. One hundred fifty community-dwelling persons aged 58-84 years were recruited from eight senior centers in King County, Washington. All participants had received AED training approximately six months previously. For this study, the participants were randomized to AED operation with or without dispatcher assistance during a simulated VF cardiac arrest. The proportions who successfully delivered a shock and the time intervals from collapse to shock were compared between the two groups. The participants who received dispatcher assistance were more likely to correctly deliver a shock with the AED during the simulated VF cardiac arrest (91% vs 68%, p = 0.001). Among those who were able to deliver a shock, the participants who received dispatcher assistance required a longer time interval from collapse to shock [median (25th, 75th percentile) = 193 seconds (165, 225) for dispatcher assistance, and 148 seconds (138, 166) for no dispatcher assistance, p = 0.001]. Among older laypersons previously trained in AED operation, dispatcher assistance may increase the proportion who can successfully deliver a shock during a VF cardiac arrest.

System Shock: The Archetype of Operational Shock

DTIC Science & Technology

2017-05-25

System Shock: The Archetype of Operational Shock A Monograph by MAJ Benjamen A. McDaniel United States Army School of Advanced Military...Mongraphs 3. DATES COVERED (From - To) JUN 2016- MAY 2017 4. TITLE AND SUBTITLE System Shock: The Archetype of Operational Shock 5a. CONTRACT NUMBER...is whether the US can use the concept of ‘ system shock’ to better operate in the Grey Zone. ‘ System shock’ combines ideas from systems theory, chaos

Septic shock

MedlinePlus

... shock; Warm shock References Munford RS, Suffredini AF. Sepsis, severe sepsis, and septic shock. In: Bennett JE, Dolin R, ... D.A.M. Editorial team. Gangrene Read more Sepsis Read more Shock Read more A.D.A. ...

Early, Goal-Directed Therapy for Septic Shock - A Patient-Level Meta-Analysis.

PubMed

Rowan, Kathryn M; Angus, Derek C; Bailey, Michael; Barnato, Amber E; Bellomo, Rinaldo; Canter, Ruth R; Coats, Timothy J; Delaney, Anthony; Gimbel, Elizabeth; Grieve, Richard D; Harrison, David A; Higgins, Alisa M; Howe, Belinda; Huang, David T; Kellum, John A; Mouncey, Paul R; Music, Edvin; Peake, Sandra L; Pike, Francis; Reade, Michael C; Sadique, M Zia; Singer, Mervyn; Yealy, Donald M

2017-06-08

After a single-center trial and observational studies suggesting that early, goal-directed therapy (EGDT) reduced mortality from septic shock, three multicenter trials (ProCESS, ARISE, and ProMISe) showed no benefit. This meta-analysis of individual patient data from the three recent trials was designed prospectively to improve statistical power and explore heterogeneity of treatment effect of EGDT. We harmonized entry criteria, intervention protocols, outcomes, resource-use measures, and data collection across the trials and specified all analyses before unblinding. After completion of the trials, we pooled data, excluding the protocol-based standard-therapy group from the ProCESS trial, and resolved residual differences. The primary outcome was 90-day mortality. Secondary outcomes included 1-year survival, organ support, and hospitalization costs. We tested for treatment-by-subgroup interactions for 16 patient characteristics and 6 care-delivery characteristics. We studied 3723 patients at 138 hospitals in seven countries. Mortality at 90 days was similar for EGDT (462 of 1852 patients [24.9%]) and usual care (475 of 1871 patients [25.4%]); the adjusted odds ratio was 0.97 (95% confidence interval, 0.82 to 1.14; P=0.68). EGDT was associated with greater mean (±SD) use of intensive care (5.3±7.1 vs. 4.9±7.0 days, P=0.04) and cardiovascular support (1.9±3.7 vs. 1.6±2.9 days, P=0.01) than was usual care; other outcomes did not differ significantly, although average costs were higher with EGDT. Subgroup analyses showed no benefit from EGDT for patients with worse shock (higher serum lactate level, combined hypotension and hyperlactatemia, or higher predicted risk of death) or for hospitals with a lower propensity to use vasopressors or fluids during usual resuscitation. In this meta-analysis of individual patient data, EGDT did not result in better outcomes than usual care and was associated with higher hospitalization costs across a broad range of patient and

On the stability of bow shocks generated by red supergiants: the case of IRC -10414

NASA Astrophysics Data System (ADS)

Meyer, D. M.-A.; Gvaramadze, V. V.; Langer, N.; Mackey, J.; Boumis, P.; Mohamed, S.

2014-03-01

In this Letter, we explore the hypothesis that the smooth appearance of bow shocks around some red supergiants (RSGs) might be caused by the ionization of their winds by external sources of radiation. Our numerical simulations of the bow shock generated by IRC -10414 (the first-ever RSG with an optically detected bow shock) show that the ionization of the wind results in its acceleration by a factor of 2, which reduces the difference between the wind and space velocities of the star and makes the contact discontinuity of the bow shock stable for a range of stellar space velocities and mass-loss rates. Our best-fitting model reproduces the overall shape and surface brightness of the observed bow shock and suggests that the space velocity and mass-loss rate of IRC -10414 are ≈50 km s-1 and ≈10-6 M⊙ yr-1, respectively, and that the number density of the local interstellar medium is ≈3 cm-3. It also shows that the bow shock emission comes mainly from the shocked stellar wind. This naturally explains the enhanced nitrogen abundance in the line-emitting material, derived from the spectroscopy of the bow shock. We found that photoionized bow shocks are ≈15-50 times brighter in optical line emission than their neutral counterparts, from which we conclude that the bow shock of IRC -10414 must be photoionized.

Simulations of Converging Shock Collisions for Shock Ignition

NASA Astrophysics Data System (ADS)

Sauppe, Joshua; Dodd, Evan; Loomis, Eric

2016-10-01

Shock ignition (SI) has been proposed as an alternative to achieving high gain in inertial confinement fusion (ICF) targets. A central hot spot below the ignition threshold is created by an initial compression pulse, and a second laser pulse drives a strong converging shock into the fuel. The collision between the rebounding shock from the compression pulse and the converging shock results in amplification of the converging shock and increases the hot spot pressure above the ignition threshold. We investigate shock collision in SI drive schemes for cylindrical targets with a polystyrene foam interior using radiation-hydrodynamics simulations with the RAGE code. The configuration is similar to previous targets fielded on the Omega laser. The CH interior results in a lower convergence ratio and the cylindrical geometry facilitates visualization of the shock transit using an axial X-ray backlighter, both of which are important for comparison to potential experimental measurements. One-dimensional simulations are used to determine shock timing, and the effects of low mode asymmetries in 2D computations are also quantified. LA-UR-16-24773.

Shock to the system: How catastrophic events and institutional relationships impact Japanese energy policymaking, resilience, and innovation

NASA Astrophysics Data System (ADS)

Sklarew, Jennifer F.

External shocks do not always generate energy system transformation. This dissertation examines how government relationships with electric utilities and the public impact whether shocks catalyze energy system change. The study analyzes Japanese energy policymaking from the oil crises through the Fukushima nuclear disaster. Findings reveal that policymakers' cooperation with and clout over electric utilities and the public can enable shocks to transform energy systems. When electric utilities wield clout, public trust in and influence on the government determine the existing system's resilience and the potential for a new system to emerge. Understanding this effect informs energy policy design and innovation.

Revisiting first type self-similar solutions of explosions containing ultrarelativistic shocks

NASA Astrophysics Data System (ADS)

Tian, Jun

2018-05-01

We revisit the first type self-similar solutions for ultrarelativistic shock waves produced by explosions propagating into cold external medium whose density profile decreases with radius as ρ ∝ r-k. The first-type solutions proposed by Blandford and McKee (hereafter BM solution) conforms to the global conservation of energy and applies when k < 4. They have been found to be invalid when k > 17/4 because of the divergence of total energy contained in the shocked fluids. So far no attention has been paid to the particle number. We use the BM solution to calculate the total particle number traversed by the shock and find that it diverges when k > 3. This is inconsistent with the finite particles in the surrounding medium. We propose a possible solution when k > 3 based on the conservation of particle number and discuss its implication for the second-type solutions.

Experimental Study of Shock Wave Interference Heating on a Cylindrical Leading Edge. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Wieting, Allan R.

1987-01-01

An experimental study of shock wave interference heating on a cylindrical leading edge representative of the cowl of a rectangular hypersonic engine inlet at Mach numbers of 6.3, 6.5, and 8.0 is presented. Stream Reynolds numbers ranged from 0.5 x 106 to 4.9 x 106 per ft. and stream total temperature ranged from 2100 to 3400 R. The model consisted of a 3" dia. cylinder and a shock generation wedge articulated to angles of 10, 12.5, and 15 deg. A fundamental understanding was obtained of the fluid mechanics of shock wave interference induced flow impingement on a cylindrical leading edge and the attendant surface pressure and heat flux distributions. The first detailed heat transfer rate and pressure distributions for two dimensional shock wave interference on a cylinder was provided along with insight into the effects of specific heat variation with temperature on the phenomena. Results show that the flow around a body in hypersonic flow is altered significantly by the shock wave interference pattern that is created by an oblique shock wave from an external source intersecting the bow shock wave produced in front of the body.

A molecular dynamic investigation for shock induced phase transition of water

NASA Astrophysics Data System (ADS)

Mitra, Nilanjan; Neogi, Anupam

2015-06-01

Atomistic equilibrium molecular dynamics (EMD) was carried out to investigate shock induced phase transition of bulk liquid water. Multi-scale shock technique (MSST) was utilized to investigate low (US = 2 . 5km /s) to strong (US = 6 . 5km /s) intensity shock response on an extended flexible three point model up to 100 ns. The thermodynamic pathway of phase transition from liquid water to ice VII was investigated using temporal variation of thermodynamic state variables, power spectrum analyses of O-H bond vibration along with temporal evolution of pair correlation function between O-O, O-H and H-H atoms. Static structure factor along with pair-distribution function extended up to 20 Å was calculated and compared against the ideal ice VII to get information regarding long range ordering. Bragg reflection at different crystal planes were evaluated to investigate percentage of crystallinity of the shocked sample. Specific questions answered in this work involves: What is the exact time frame after the passage of shock at certain intensity in which nucleation of solid phase can be observed? Is it a complete or partial phase transition? Are external nucleators essential for this transformation? What is the percentage of crystallinity of the nucleated phase?

Risk of fatal cerebrovascular accidents after external beam radiation therapy for early-stage glottic laryngeal cancer.

PubMed

Swisher-McClure, Samuel; Mitra, Nandita; Lin, Alexander; Ahn, Peter; Wan, Fei; O'Malley, Bert; Weinstein, Gregory S; Bekelman, Justin E

2014-05-01

This study compared the risk of fatal cerebrovascular accidents (CVAs) in patients with early-stage glottic laryngeal cancer receiving surgery or external beam radiation therapy (EBRT). Using a competing risks survival analysis, we compared the risk of death because of CVA among patients with early-stage glottic laryngeal cancer receiving surgery or EBRT in the Surveillance, Epidemiology, and End Results (SEER) database. The cumulative incidence of fatal CVA at 15 years was higher in patients receiving EBRT (2.8%; 95% confidence interval [CI], 2.3% to 3.4%) compared to surgery (1.5%; 95% CI, 0.8% to 2.3%; p = .024). In multivariable competing risks regression models, EBRT remained associated with an increased risk of fatal CVA compared to surgery (adjusted hazard ratio [HR], 1.75; 95% CI, 1.04-2.96; p = .037). Treatment for early-stage glottic laryngeal cancer with EBRT was associated with a small increase in the risk of late fatal CVA events relative to surgery. Copyright © 2013 Wiley Periodicals, Inc.

Culture shock and travelers.

PubMed

Stewart, L; Leggat, P A

1998-06-01

As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate

Impact-induced shock and the formation of natural quasicrystals in the early solar system

NASA Astrophysics Data System (ADS)

Hollister, Lincoln S.; Bindi, Luca; Yao, Nan; Poirier, Gerald R.; Andronicos, Christopher L.; MacPherson, Glenn J.; Lin, Chaney; Distler, Vadim V.; Eddy, Michael P.; Kostin, Alexander; Kryachko, Valery; Steinhardt, William M.; Yudovskaya, Marina; Eiler, John M.; Guan, Yunbin; Clarke, Jamil J.; Steinhardt, Paul J.

2014-06-01

The discovery of a natural quasicrystal, icosahedrite (Al63Cu24Fe13), accompanied by khatyrkite (CuAl2) and cupalite (CuAl) in the CV3 carbonaceous chondrite Khatyrka has posed a mystery as to what extraterrestrial processes led to the formation and preservation of these metal alloys. Here we present a range of evidence, including the discovery of high-pressure phases never observed before in a CV3 chondrite, indicating that an impact shock generated a heterogeneous distribution of pressures and temperatures in which some portions reached at least 5 GPa and 1,200 °C. The conditions were sufficient to melt Al-Cu-bearing minerals, which then rapidly solidified into icosahedrite and other Al-Cu metal phases. The meteorite also contains heretofore unobserved phases of iron-nickel and iron sulphide with substantial amounts of Al and Cu. The presence of these phases in Khatyrka provides further proof that the Al-Cu alloys are natural products of unusual processes that occurred in the early solar system.

Dynamic structure of confined shocks undergoing sudden expansion

NASA Astrophysics Data System (ADS)

Abate, G.; Shyy, W.

2002-01-01

The gas dynamic phenomenon associated with a normal shock wave within a tube undergoing a sudden area expansion consists of highly transient flow and diffraction that give rise to turbulent, compressible, vortical flows. These interactions can occur at time scales typically ranging from micro- to milliseconds. In this article, we review recent experimental and numerical results to highlight the flow phenomena and main physical mechanisms associated with this geometry. The topics addressed include time-accurate shock and vortex locations, flowfield evolution and structure, wall-shock Mach number, two- vs. three-dimensional sudden expansions, and the effect of viscous dissipation on planar shock-front expansions. Between axisymmetric and planar geometries, the flow structure evolves very similarly early on in the sudden expansion process (i.e., within the first two shock tube diameters). Both numerical and experimental studies confirm that the trajectory of the vortex formed at the expansion corner is convected into the flowfield faster in the axisymmetric case than the planar case. The lateral propagation of the vortices correlates very well between axisymmetric and planar geometries. In regard to the rate of dissipation of turbulent kinetic energy (TKE) for a two-dimensional planar shock undergoing a sudden expansion within a confined chamber, calculations show that the solenoidal dissipation is confined to the region of high strain rates arising from the expansion corner. Furthermore, the dilatational dissipation is concentrated mainly at the curvature of the incident, reflected, and barrel shock fronts. The multiple physical mechanisms identified, including shock-strain rate interaction, baroclinic effect, vorticity generation, and different aspects of viscous dissipation, have produced individual and collective flow structures observed experimentally.

Fault Detection for Automotive Shock Absorber

NASA Astrophysics Data System (ADS)

Hernandez-Alcantara, Diana; Morales-Menendez, Ruben; Amezquita-Brooks, Luis

2015-11-01

Fault detection for automotive semi-active shock absorbers is a challenge due to the non-linear dynamics and the strong influence of the disturbances such as the road profile. First obstacle for this task, is the modeling of the fault, which has been shown to be of multiplicative nature. Many of the most widespread fault detection schemes consider additive faults. Two model-based fault algorithms for semiactive shock absorber are compared: an observer-based approach and a parameter identification approach. The performance of these schemes is validated and compared using a commercial vehicle model that was experimentally validated. Early results shows that a parameter identification approach is more accurate, whereas an observer-based approach is less sensible to parametric uncertainty.

Euler-Lagrange Simulations of Shock Wave-Particle Cloud Interaction

NASA Astrophysics Data System (ADS)

Koneru, Rahul; Rollin, Bertrand; Ouellet, Frederick; Park, Chanyoung; Balachandar, S.

2017-11-01

Numerical experiments of shock interacting with an evolving and fixed cloud of particles are performed. In these simulations we use Eulerian-Lagrangian approach along with state-of-the-art point-particle force and heat transfer models. As validation, we use Sandia Multiphase Shock Tube experiments and particle-resolved simulations. The particle curtain upon interaction with the shock wave is expected to experience Kelvin-Helmholtz (KH) and Richtmyer-Meshkov (RM) instabilities. In the simulations evolving the particle cloud, the initial volume fraction profile matches with that of Sandia Multiphase Shock Tube experiments, and the shock Mach number is limited to M =1.66. Measurements of particle dispersion are made at different initial volume fractions. A detailed analysis of the influence of initial conditions on the evolution of the particle cloudis presented. The early time behavior of the models is studied in the fixed bed simulations at varying volume fractions and shock Mach numbers.The mean gas quantities are measured in the context of 1-way and 2-way coupled simulations. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, Contract No. DE-NA0002378.

Does Parental Psychological Control Relate to Internalizing and Externalizing Problems in Early Childhood? An Examination Using the Berkeley Puppet Interview

ERIC Educational Resources Information Center

Stone, Lisanne L.; Otten, Roy; Janssens, Jan M. A. M.; Soenens, Bart; Kuntsche, Emmanuel; Engels, Rutger C. M. E.

2013-01-01

Parental psychological control has been linked to symptoms of psychopathology in adolescence, yet less is known about its correlates in childhood. The current study is among the first to address whether psychological control is related to internalizing and externalizing problems in early childhood. A community sample of 298 children aged 7.04…

Attenuated adult biphasic shocks for prolonged pediatric ventricular fibrillation: support for pediatric automated defibrillators.

PubMed

Berg, Robert A

2004-09-01

To evaluate published data regarding the treatment of prolonged pediatric defibrillation, with special emphasis on the use of attenuated adult biphasic shocks for pediatric defibrillation. Review relevant human and animal literature. Rhythm analysis algorithms from two manufacturers of automated external defibrillators can accurately distinguish shockable from nonshockable rhythms in children. Theoretical considerations and transthoracic impedance data from animals and children suggest that pediatric defibrillation doses should not necessarily vary in a simple weight-based manner. Two piglet studies have established that an attenuated adult biphasic dosage can be successfully used for 3.5- to 24-kg animals in ventricular fibrillation. One study established that the attenuated adult biphasic dosage was at least as safe and effective as the standard monophasic weight-based dosing. This review supports the American Heart Association's new guidelines for pediatric automated external defibrillator usage: "Automated external defibrillators may be used for children 1 to 8 yrs of age who have no signs of circulation. Ideally the device should deliver a pediatric dose. The arrhythmia detection system used in the device should demonstrate high specificity for pediatric shockable rhythms, i.e., it will not recommend delivery of a shock for nonshockable rhythms."

Shock-isolation material selection for electronic packages in hard-target environment

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

Stotts, Jarrett Eugene

High velocity munitions and kinetic penetrators experience monumental external forces, impulses, and accelerations. The hard target environment is immensely taxing on sophisticated electronic components and recorders designed to retrieve valuable data related to the systems performance and characteristics in the periods of flight, impact, and post-impact. Such electronic systems have upper limits of overall shock intensity which, if exceeded, will either shorten the operating life of the parts or risk destruction resulting in loss of both the data and the principal value of the recorder. The focus of this project was to refine the categorization of leading material types formore » encapsulation and passive shock isolation and implement them in a method useable for a wide variety of environments. Namely, a design methodology capable of being tailored to the specific impact conditions to maximize the lively hood of sensitive electronics and the information recorded. The results of the study concluded that the materials observed under consistent dynamic high strain rate tests, which include Conathane® EN-4/9, Slygard®-184, and Stycast™-2651, behaved well in certain aspects of energy transmission and shock when considering the frequency environment or package coupled with the isolation material’s application. Key points about the implementation of the materials in extreme shock environments is discussed with the connection to energy analysis, loss attributes, and pulse transmissibility modeling. However, attempts to model the materials solely based on energy transmissibility in the frequency domain using only external experimental data and simplified boundary conditions was not found to be consistent with that acquired from the pressure bar experiments. Further work will include the addition of further material experimentation of the encapsulants in other frequency and temperature states, confined and pre-load boundary states, and composite constructions.« less

Comparative performance assessment of commercially available automatic external defibrillators: A simulation and real-life measurement study of hands-off time.

PubMed

Savastano, Simone; Vanni, Vincenzo; Burkart, Roman; Raimondi, Maurizio; Canevari, Fabrizio; Molinari, Simone; Baldi, Enrico; Danza, Aurora I; Caputo, Maria Luce; Mauri, Romano; Regoli, Francois; Conte, Giulio; Benvenuti, Claudio; Auricchio, Angelo

2017-01-01

Early and good quality cardiopulmonary resuscitation (CPR) and the use of automated external defibrillators (AEDs) improve cardiac arrest patients' survival. However, AED peri- and post-shock/analysis pauses may reduce CPR effectiveness. The time performance of 12 different commercially available AEDs was tested in a manikin based scenario; then the AEDs recordings from the same tested models following the clinical use both in Pavia and Ticino were analyzed to evaluate the post-shock and post-analysis time. None of the AEDs was able to complete the analysis and to charge the capacitors in less than 10s and the mean post-shock pause was 6.7±2.4s. For non-shockable rhythms, the mean analysis time was 10.3±2s and the mean post-analysis time was 6.2±2.2s. We analyzed 154 AED records [104 by Emergency Medical Service (EMS) rescuers; 50 by lay rescuers]. EMS rescuers were faster in resuming CPR than lay rescuers [5.3s (95%CI 5-5.7) vs 8.6s (95%CI 7.3-10). AEDs showed different performances that may reduce CPR quality mostly for those rescuers following AED instructions. Both technological improvements and better lay rescuers training might be needed. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Methodology for the Design of Streamline-Traced External-Compression Supersonic Inlets

NASA Technical Reports Server (NTRS)

Slater, John W.

2014-01-01

A design methodology based on streamline-tracing is discussed for the design of external-compression, supersonic inlets for flight below Mach 2.0. The methodology establishes a supersonic compression surface and capture cross-section by tracing streamlines through an axisymmetric Busemann flowfield. The compression system of shock and Mach waves is altered through modifications to the leading edge and shoulder of the compression surface. An external terminal shock is established to create subsonic flow which is diffused in the subsonic diffuser. The design methodology was implemented into the SUPIN inlet design tool. SUPIN uses specified design factors to design the inlets and computes the inlet performance, which includes the flow rates, total pressure recovery, and wave drag. A design study was conducted using SUPIN and the Wind-US computational fluid dynamics code to design and analyze the properties of two streamline-traced, external-compression (STEX) supersonic inlets for Mach 1.6 freestream conditions. The STEX inlets were compared to axisymmetric pitot, two-dimensional, and axisymmetric spike inlets. The STEX inlets had slightly lower total pressure recovery and higher levels of total pressure distortion than the axisymmetric spike inlet. The cowl wave drag coefficients of the STEX inlets were 20% of those for the axisymmetric spike inlet. The STEX inlets had external sound pressures that were 37% of those of the axisymmetric spike inlet, which may result in lower adverse sonic boom characteristics. The flexibility of the shape of the capture cross-section may result in benefits for the integration of STEX inlets with aircraft.

The History of the APS Topical Group on Shock Compression of Condensed Matter

NASA Astrophysics Data System (ADS)

Forbes, Jerry W.

2002-07-01

In order to provide broader scientific recognition and to advance the science of shock compressed condensed matter, a group of American Physical Society (APS) members worked within the Society to make this field an active part of the APS. Individual papers were presented at APS meetings starting in the 1940's and shock wave sessions were organized starting with the 1967 Pasadena meeting. Shock wave topical conferences began in 1979 in Pullman, WA. Signatures were obtained on a petition in 1984 from a balanced cross-section of the shock wave community to form an APS Topical Group (TG). The APS Council officially accepted the formation of the Shock Compression of Condensed Matter (SCCM) TG at its October 1984 meeting. This action firmly aligned the shock wave field with a major physical science organization. Most early topical conferences were sanctioned by the APS while those held after 1992 were official APS meetings. The topical group organizes a shock wave topical conference in odd numbered years while participating in shock wave/high pressure sessions at APS general meetings in even numbered years.

Shock Test Program. Shock Isolation Design Manual for SAFEGUARD TSE Systems and Equipment.

DTIC Science & Technology

1973-08-01

under the direction of the Huntsville Division, Corps of Engineers. Much of the information in Part I and Part II is extracted from " Development of...49 3.2.2 Configuration Development 1-50 3.2.3 Suspension Arrangements 1-51 TABLE OF CONTENTS (Continued) Page 3.2.4 Platform Design 1-56 3.2.5 Elastic...shock isolation systems were considered in the design of the early NIKE-X facilities. As more descriptive prediction methods were developed and employed

Initial fractal exponent of heart-rate variability is associated with success of early resuscitation in patients with severe sepsis or septic shock: a prospective cohort study

PubMed Central

Brown, Samuel M.; Tate, Quinn; Jones, Jason P.; Knox, Daniel; Kuttler, Kathryn G.; Lanspa, Michael; Rondina, Matthew T.; Grissom, Colin K.; Behera, Subhasis; Mathews, V.J.; Morris, Alan

2013-01-01

Introduction Heart-rate variability reflects autonomic nervous system tone as well as the overall health of the baroreflex system. We hypothesized that loss of complexity in heart-rate variability upon ICU admission would be associated with unsuccessful early resuscitation of sepsis. Methods We prospectively enrolled patients admitted to ICUs with severe sepsis or septic shock from 2009 to 2011. We studied 30 minutes of EKG, sampled at 500 Hz, at ICU admission and calculated heart-rate complexity via detrended fluctuation analysis. Primary outcome was vasopressor independence at 24 hours after ICU admission. Secondary outcome was 28-day mortality. Results We studied 48 patients, of whom 60% were vasopressor independent at 24 hours. Five (10%) died within 28 days. The ratio of fractal alpha parameters was associated with both vasopressor independence and 28-day mortality (p=0.04) after controlling for mean heart rate. In the optimal model, SOFA score and the long-term fractal alpha parameter were associated with vasopressor independence. Conclusions Loss of complexity in heart rate variability is associated with worse outcome early in severe sepsis and septic shock. Further work should evaluate whether complexity of heart rate variability (HRV) could guide treatment in sepsis. PMID:23958243

Sources of Shock Waves in the Protoplanetary Disk

NASA Astrophysics Data System (ADS)

Boss, A. P.; Durisen, R. H.

2005-12-01

Finding an appropriate heat source for melting the chondrules that constitute the bulk of many primitive meteorites is perhaps the most important outstanding problem in all of meteoritics. Shock waves within the Solar Nebula are one possible means for accomplishing this provided that they move with respect to the precursor aggregates at speeds of ~ 6 to 9 km s-1 in environments with appropriate nebular pressures and densities. Here we briefly review the status of four different mechanisms which have been proposed as sources of such shock fronts. We argue that two of them, the accretion shock at the nebular surface and shocks propagating inside the nebula launched by the impact of gas clumps falling onto the disk, are unlikely to work. Bow shocks driven by 1000-km-size planetesimals show more promise, but require the presence of Jupiter to raise the eccentricities of the planetesimals. We then focus this chapter on the fourth mechanism, which may be the dominant source of shocks in the early nebula. Wood (1996) proposed that the chondrule-producing shocks were due to nebular spiral arms. This hypothesis is now strongly supported by recent calculations of the evolution of gravitationally unstable disks. In a gaseous disk capable of forming Jupiter, the disk gas must have been close to marginal gravitational instability near or beyond Jupiter's orbit. Massive clumps and spirals due to such instability can drive spiral shock fronts inward with shock speeds as large as ~ 10 km s-1 at asteroidal orbits, sufficient to account for chondrule formation. Once Jupiter forms, it may either continue to drive strong shock fronts at asteroidal distances, or it may pump up the eccentricity of planetesimals, leading to chondrule processing for as long as the inner disk gas survives, a few Myr or so. Mixing and transport of solids in an unstable disk results in a scenario that unifies chondrite formation from chondrules, refractory inclusions, and matrix grains with disk processes

Anisotropic responses and initial decomposition of condensed-phase β-HMX under shock loadings via molecular dynamics simulations in conjunction with multiscale shock technique.

PubMed

Ge, Ni-Na; Wei, Yong-Kai; Song, Zhen-Fei; Chen, Xiang-Rong; Ji, Guang-Fu; Zhao, Feng; Wei, Dong-Qing

2014-07-24

Molecular dynamics simulations in conjunction with multiscale shock technique (MSST) are performed to study the initial chemical processes and the anisotropy of shock sensitivity of the condensed-phase HMX under shock loadings applied along the a, b, and c lattice vectors. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. Our results show that there is a difference between lattice vector a (or c) and lattice vector b in the response to a shock wave velocity of 11 km/s, which is investigated through reaction temperature and relative sliding rate between adjacent slipping planes. The response along lattice vectors a and c are similar to each other, whose reaction temperature is up to 7000 K, but quite different along lattice vector b, whose reaction temperature is only up to 4000 K. When compared with shock wave propagation along the lattice vectors a (18 Å/ps) and c (21 Å/ps), the relative sliding rate between adjacent slipping planes along lattice vector b is only 0.2 Å/ps. Thus, the small relative sliding rate between adjacent slipping planes results in the temperature and energy under shock loading increasing at a slower rate, which is the main reason leading to less sensitivity under shock wave compression along lattice vector b. In addition, the C-H bond dissociation is the primary pathway for HMX decomposition in early stages under high shock loading from various directions. Compared with the observation for shock velocities V(imp) = 10 and 11 km/s, the homolytic cleavage of N-NO2 bond was obviously suppressed with increasing pressure.

Cystatin C as an early marker of acute kidney injury in septic shock.

PubMed

Ortuño-Andériz, F; Cabello-Clotet, N; Vidart-Simón, N; Postigo-Hernández, C; Domingo-Marín, S; Sánchez-García, M

2015-03-01

To describe the utility of determining plasma cystatinC concentrations in the diagnosis of acute incident kidney injury in septic shock. Prospective series of 50 patients with septic shock and plasma creatinine levels <2mg/dL hospitalized in an intensive care unit. Clinical and laboratory follow-ups were conducted, with measurements of cystatinC, urea and plasma creatinine levels from the diagnosis of septic shock to 5days later. The severity of the septic shock was assessed with the RIFLE scale. Twenty patients (40%) developed acute kidney injury: 8 (16%) were categorized as RIFLE-R, 5 (10%) as RIFLE-I and 7 (14%) as RIFLE-F. All patients categorized as RIFLE-F required extracorporeal renal clearance. Eighteen (36%) patients died, 8 (20%) of whom had developed acute kidney injury in their evolution. There was poor correlation between plasma creatinine and cystatin C levels (r=.501; P=.001), which disappeared upon reaching any degree of renal impairment on the RIFLE scale. CystatinC levels increased earlier and were better able to identify patients who would develop serious renal function impairment (RIFLE-F) than creatinine and urea levels. The initial cystatinC levels were related to mortality at 30days (OR=1.16; 95%CI: 03-.85). For patients who developed acute septic kidney injury, the plasma cystatinC levels increased before the classical markers of renal function. CystatinC also constitutes a severity biomarker that correlates with progression to RIFLE-F, the need for extrarenal clearance and, ultimately, mortality. This precocity could be useful for starting measures that prevent the progression of renal dysfunction. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Evidence for Coordination and Redox Changes of Iron in Shocked Feldspar from Synchrotron MicroXANES

NASA Technical Reports Server (NTRS)

Delaney, J. S.; Dyar, M. D.; Hoerz, F.; Johnson, J. R.

2003-01-01

Shock modification of feldspar has been documented and experimentally reproduced in many studies since the recognition of maskelynite in Shergotty. Experimentally shocked feldspar samples have been well studied using chemical and crystallographic techniques. The crystallographic, site-specific characterization of major and minor elements is less well documented. We present early x-ray absorption (XAS) spectral data for a suite of albitite samples that were experimentally shocked at pressures between 17 and 50 Gpa.

Markets, Herding and Response to External Information

PubMed Central

Carro, Adrián; Toral, Raúl; San Miguel, Maxi

2015-01-01

We focus on the influence of external sources of information upon financial markets. In particular, we develop a stochastic agent-based market model characterized by a certain herding behavior as well as allowing traders to be influenced by an external dynamic signal of information. This signal can be interpreted as a time-varying advertising, public perception or rumor, in favor or against one of two possible trading behaviors, thus breaking the symmetry of the system and acting as a continuously varying exogenous shock. As an illustration, we use a well-known German Indicator of Economic Sentiment as information input and compare our results with Germany’s leading stock market index, the DAX, in order to calibrate some of the model parameters. We study the conditions for the ensemble of agents to more accurately follow the information input signal. The response of the system to the external information is maximal for an intermediate range of values of a market parameter, suggesting the existence of three different market regimes: amplification, precise assimilation and undervaluation of incoming information. PMID:26204451

Markets, Herding and Response to External Information.

PubMed

Carro, Adrián; Toral, Raúl; San Miguel, Maxi

2015-01-01

We focus on the influence of external sources of information upon financial markets. In particular, we develop a stochastic agent-based market model characterized by a certain herding behavior as well as allowing traders to be influenced by an external dynamic signal of information. This signal can be interpreted as a time-varying advertising, public perception or rumor, in favor or against one of two possible trading behaviors, thus breaking the symmetry of the system and acting as a continuously varying exogenous shock. As an illustration, we use a well-known German Indicator of Economic Sentiment as information input and compare our results with Germany's leading stock market index, the DAX, in order to calibrate some of the model parameters. We study the conditions for the ensemble of agents to more accurately follow the information input signal. The response of the system to the external information is maximal for an intermediate range of values of a market parameter, suggesting the existence of three different market regimes: amplification, precise assimilation and undervaluation of incoming information.

Early psychosocial interventions after disasters, terrorism and other shocking events: is there a gap between norms and practice in Europe?

PubMed Central

Te Brake, Hans

2013-01-01

Background Internationally, several initiatives exist to describe standards for post-disaster psychosocial care. Objective This study explored the level of consensus of experts within Europe on a set of recommendations on early psychosocial intervention after shocking events (Dutch guidelines), and to what degree these standards are implemented into mental health care practice. Methods Two hundred and six (mental) health care professionals filled out a questionnaire to assess the extent to which they consider the guidelines’ scope and recommendations relevant and part of the regular practice in their own country. Forty-five European experts from 24 EU countries discussed the guidelines at an international seminar. Results The data suggest overall agreement on the standards although many of the recommendations appear not (yet) to be embedded in everyday practice. Conclusions Although large consensus exists on standards for early psychosocial care, a chasm between norms and practice appears to exist throughout the EU, stressing the general need for investments in guideline development and implementation. PMID:23393613

Early Conversion of External Fixation to Interlocked Nailing in Open Fractures of Both Bone Leg Assisted with Vacuum Closure (VAC) - Final Outcome

PubMed Central

Raj, Manish; Kumar, Sunil; Singh, Pulkesh; Kumar, Dinesh; Singh, Jasveer; Deep, Akash

2016-01-01

Introduction Management of compound grade III fractures of both bone leg includes external stabilization for long period, followed by various soft tissue coverage procedures. Primary interlocking of tibia had been also done with variable results. External fixation for long time without any bone loss often leads to infected nonunion, loss of reduction, pin tract infection and failure of fixation, primary interlocking in compound grade III fractures had shown high medullary infection rate. We managed all cases of compound grade III A/B fractures with primary external fixation, simultaneous wound management using vacuum assisted closure (VAC) followed by early conversion to interlocking within 2 weeks of fixator application. Aim To determine the effectiveness of vacuum assisted closure (VAC) for the early conversion of external fixator to definitive interlocking in open fractures of the both bone leg. Materials and Methods In current study we selected 84 cases of compound grade IIIA/B diaphyseal fractures of both bone leg during period of May 2010 to September 2013. We managed these cases by immediate debridement and application of external fixation followed by repeated debridement, application of vacuum assisted closure (VAC) and conversion to interlocking within two weeks. Results Out of 84 cases union was achieved in 80(95%) of cases with definitive tibial interlocking. Excellent to good result were obtained in 77(91.8%) of cases and fair to poor result seen in rest of 7(8.2%) of cases according to modified Ketenjian’s criteria. 5 out of these 7 poor result group cases were from Compound Grade III B group to start with. Deep infection rate in our series were 7% i.e. total 6 cases and 4 out of these were from compound Grade III B group to start with. Conclusion Vacuum assisted closure (VAC) give a good help for rapid closure of the wound and help in early conversion to definitive intramedullary nailing. Reamed nail could well be used in compound grade IIIA

Infancy parenting and externalizing psychopathology from childhood through adulthood: developmental trends.

PubMed

Lorber, Michael F; Egeland, Byron

2009-07-01

Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy parenting was associated with externalizing problems at kindergarten and first grade (mother report) as well as at 23 and 26 years (self report). Infancy parenting was not significantly associated with either mothers' or youths' reports of externalizing problems at 16 years. These findings are consistent with the notion that poor-quality infancy parenting is a risk factor for externalizing problems in developmental periods for which externalizing behavior is most deviant.

Prognostic Value of Venous to Arterial Carbon Dioxide Difference during Early Resuscitation in Critically Ill Patients with Septic Shock.

PubMed

Helmy, Tamer Abdallah; El-Reweny, Ehab Mahmoud; Ghazy, Farahat Gomaa

2017-09-01

The partial pressure of venous to arterial carbon dioxide gradient (PCO 2 gap) is considered as an alternative marker of tissue hypoperfusion and has been used to guide treatment for shock. The aim of this study was to investigate the prognostic value of venous-to-arterial carbon dioxide difference during early resuscitation of patients with septic shock and compared it with that of lactate clearance and Acute Physiology and Chronic Health Evaluation II (APACHE-II) score. Forty patients admitted to one Intensive Care Unit were enrolled. APACHE-II score was calculated on admission. An arterial blood gas, central venous, and lactate samples were obtained on admission and after 6 h, and lactate clearance was calculated. Patients were classified retrospectively into Group I (survivors) and Group II (nonsurvivors). Pv-aCO 2 difference in the two groups was evaluated. Data were fed to the computer and analyzed using IBM SPSS software package version 20.0. At T0, Group II showed high PCO 2 gap (8.37 ± 1.36 mmHg) than Group I (7.55 ± 0.95 mmHg) with statistically significant difference ( P = 0.030). While at T6, Group II showed higher PCO 2 gap (9.48 ± 1.47 mmHg) with statistically significant difference ( P < 0.001) and higher mean lactate values (62.71 ± 23.66 mg/dl) with statistically significant difference ( P < 0.001) than Group I where PCO 2 gap and mean lactate values became much lower, 5.91 ± 1.12 mmHg and 33.61 ± 5.80 mg mg/dl, respectively. Group I showed higher lactate clearance (25.42 ± 6.79%) with statistically significant difference ( P < 0.001) than Group II (-69.40-15.46%). High PCO 2 gap >7.8 mmHg after 6 h from resuscitation of septic shock patients is associated with high mortality.

Involvement of the sieve element cytoskeleton in electrical responses to cold shocks.

PubMed

Hafke, Jens B; Ehlers, Katrin; Föller, Jens; Höll, Sabina-Roxana; Becker, Stefanie; van Bel, Aart J E

2013-06-01

This study dealt with the visualization of the sieve element (SE) cytoskeleton and its involvement in electrical responses to local cold shocks, exemplifying the role of the cytoskeleton in Ca(2+)-triggered signal cascades in SEs. High-affinity fluorescent phalloidin as well as immunocytochemistry using anti-actin antibodies demonstrated a fully developed parietal actin meshwork in SEs. The involvement of the cytoskeleton in electrical responses and forisome conformation changes as indicators of Ca(2+) influx was investigated by the application of cold shocks in the presence of diverse actin disruptors (latrunculin A and cytochalasin D). Under control conditions, cold shocks elicited a graded initial voltage transient, ΔV1, reduced by external La(3+) in keeping with the involvement of Ca(2+) channels, and a second voltage transient, ΔV2. Cytochalasin D had no effect on ΔV1, while ΔV1 was significantly reduced with 500 nm latrunculin A. Forisome dispersion was triggered by cold shocks of 4°C or greater, which was indicative of an all-or-none behavior. Forisome dispersion was suppressed by incubation with latrunculin A. In conclusion, the cytoskeleton controls cold shock-induced Ca(2+) influx into SEs, leading to forisome dispersion and sieve plate occlusion in fava bean (Vicia faba).

Evaluation of the response of concurrent high dose rate intracavitary brachytherapy with external beam radiotherapy in management of early stage carcinoma cervix.

PubMed

Patidar, Arvind Kumar; Kumar, H S; Walke, Rahul V; Hirapara, Pushpendra H; Jakhar, Shankar Lal; Bardia, M R

2012-10-01

To evaluate local disease control and early complications of concomitant brachytherapy with external beam-radiotherapy in early stage carcinoma cervix. Fifty patients of early stage carcinoma cervix (FIGO-IB/IIA) were randomly divided into study group concomitant external beam irradiation (EBRT) and HDR-ICBT (intra-cavitary brachytherapy, xrt = 50 Gy/25 Fr, HDR 5.2 Gy*5 Fr) and the control group EBRT followed by HDR-ICBT (xrt = 50 Gy/25 Fr, HDR 7.5 Gy*3 Fr). Acute reactions and local disease response were compared between treatment and at 6-month follow up. Median overall treatment times were 38 and 61 days in the study and the control groups, respectively. Acute skin reactions and diarrhea were more in the study but manageable. At the completion of the study, there were 80 and 68 % complete responses, 16 and 20 % partial responses, 0 and 8 % stable diseases in the study group and the control group, respectively. Response was better in the study group but statistically insignificant. Larger number of patients and longer follow up are required to arrive at concrete conclusion.

Treatment of shock.

PubMed

Hardaway, R M

1979-03-01

In order to effectively treat shock the physician must understand the physiology of shock. Shock patients may have a low, normal, or high arterial blood pressure, and the blood volume may be below normal, normal, or above normal. Shock is not necessarily accompanied by low arterial pH or low peripheral resistance. Most cases of acute traumatic and hemorrhagic shock show a high arterial pH, partly due to the blowing off of CO2, despite an elevated blood lactic acid level. Most patients also show a very high resistance. A factor that all shock patients have in common is a deficient capillary perfusion, or an insufficient amount of blood flowing through the capillaries. The cornerstone of the treatment of hypovolemic shock is the administration of adequate amounts of the right kinds of intravenous fluids. Focus is on classification of shock (reversible shock, irreversible or fatal shock, hypovolemia), the heart in shock, respiration, drugs (steroids, vasoactive drugs), and disseminated intravascular coagulation. If edema is a problem, diuretics may be helpful. Antibiotics for infection are very important in sepsis and septic shock. Supportive drugs are also important. Steroids and vasoactive drugs have a secondary place in the treatment of shock, and they should be used when these treatments have failed to produce an adequate blood pressure and urinary output.

The Impact of the Sepsis-3 Septic Shock Definition on Previously Defined Septic Shock Patients.

PubMed

Sterling, Sarah A; Puskarich, Michael A; Glass, Andrew F; Guirgis, Faheem; Jones, Alan E

2017-09-01

The Third International Consensus Definitions Task Force (Sepsis-3) recently recommended changes to the definitions of sepsis. The impact of these changes remains unclear. Our objective was to determine the outcomes of patients meeting Sepsis-3 septic shock criteria versus patients meeting the "old" (1991) criteria of septic shock only. Secondary analysis of two clinical trials of early septic shock resuscitation. Large academic emergency departments in the United States. Patients with suspected infection, more than or equal to two systemic inflammatory response syndrome criteria, and systolic blood pressure less than 90 mm Hg after fluid resuscitation. Patients were further categorized as Sepsis-3 septic shock if they demonstrated hypotension, received vasopressors, and exhibited a lactate greater than 2 mmol/L. We compared in-hospital mortality in patients who met the old definition only with those who met the Sepsis-3 criteria. Four hundred seventy patients were included in the present analysis. Two hundred (42.5%) met Sepsis-3 criteria, whereas 270 (57.4%) met only the old definition. Patients meeting Sepsis-3 criteria demonstrated higher severity of illness by Sequential Organ Failure Assessment score (9 vs 5; p < 0.001) and mortality (29% vs 14%; p < 0.001). Subgroup analysis of 127 patients meeting only the old definition demonstrated significant mortality benefit following implementation of a quantitative resuscitation protocol (35% vs 10%; p = 0.006). In this analysis, 57% of patients meeting old definition for septic shock did not meet Sepsis-3 criteria. Although Sepsis-3 criteria identified a group of patients with increased organ failure and higher mortality, those patients who met the old criteria and not Sepsis-3 criteria still demonstrated significant organ failure and 14% mortality rate.

Aspherical Supernovae and Oblique Shock Breakout

NASA Astrophysics Data System (ADS)

Afsariardchi, Niloufar; Matzner, Christopher D.

2017-02-01

In an aspherical supernova explosion, shock emergence is not simultaneous and non-radial flows develop near the stellar surface. Oblique shock breakouts tend to be easily developed in compact progenitors like stripped-envelop core collapse supernovae. According to Matzner et al. (2013), non-spherical explosions develop non-radial flows that alters the observable emission and radiation of a supernova explosion. These flows can limit ejecta speed, change the distribution of matter and heat of the ejecta, suppress the breakout flash, and most importantly engender collisions outside the star. We construct a global numerical FLASH hydrodynamic simulation in a two dimensional spherical coordinate, focusing on the non-relativistic, adiabatic limit in a polytropic envelope to see how these fundamental differences affect the early light curve of core-collapse SNe.

[Automatic external defibrillator--mode of operation and clinical use].

PubMed

Wieneke, H; Konorza, T; Breuckmann, F; Reinsch, N; Erbel, R

2008-10-01

Every year about 100,000 persons die from sudden cardiac death (SCD) in Germany. Although many efforts have been undertaken, mortality remains high. Only 2 - 10% of patients with out-off hospital SCD can finally be discharged from hospital after resuscitation. Observational studies show that ventricular fibrillation and ventricular tachycardia are the primary arrhythmias underlying SCD. For both arrhythmias the main determinant for survival is the time between onset and termination by defibrillation. The chance of survival declines by 10% for every minute of delay. These findings prompted the concept of early defibrillation by first responders. Many studies have shown that non-medical professionals, like police men, firemen or security officers, often arrive at the patient more early than emergency medical service. Thus, "smart" automated external defibrillators (AEDs), designed to identify VT/VF and prompt the user when to deliver a shock were introduced. These devices allow lay rescuers to terminate ventricular arrhythmias before the arrival of medical professionals. By this approach the time to defibrillation could be reduced and a significant reduction in mortality could be documented in selected situation. These encouraging results initialled the installation of AED at public places like aircrafts, airports, underground stations and shopping males. Due to the success of this approach doctors are more and more confronted with questions about technical details, reliability and cost effectiveness of these devices. The present review should give an overview about the current studies and guidelines.

Aftershocks of Chile's Earthquake for an Ongoing, Large-Scale Experimental Evaluation

ERIC Educational Resources Information Center

Moreno, Lorenzo; Trevino, Ernesto; Yoshikawa, Hirokazu; Mendive, Susana; Reyes, Joaquin; Godoy, Felipe; Del Rio, Francisca; Snow, Catherine; Leyva, Diana; Barata, Clara; Arbour, MaryCatherine; Rolla, Andrea

2011-01-01

Evaluation designs for social programs are developed assuming minimal or no disruption from external shocks, such as natural disasters. This is because extremely rare shocks may not make it worthwhile to account for them in the design. Among extreme shocks is the 2010 Chile earthquake. Un Buen Comienzo (UBC), an ongoing early childhood program in…

Toxic shock syndrome

MedlinePlus

Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

Subset of heat-shock transcription factors required for the early response of Arabidopsis to excess light

PubMed Central

Jung, Hou-Sung; Crisp, Peter A.; Estavillo, Gonzalo M.; Cole, Benjamin; Hong, Fangxin; Mockler, Todd C.; Pogson, Barry J.; Chory, Joanne

2013-01-01

Sunlight provides energy for photosynthesis and is essential for nearly all life on earth. However, too much or too little light or rapidly fluctuating light conditions cause stress to plants. Rapid changes in the amount of light are perceived as a change in the reduced/oxidized (redox) state of photosynthetic electron transport components in chloroplasts. However, how this generates a signal that is relayed to changes in nuclear gene expression is not well understood. We modified redox state in the reference plant, Arabidopsis thaliana, using either excess light or low light plus the herbicide DBMIB (2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone), a well-known inhibitor of photosynthetic electron transport. Modification of redox state caused a change in expression of a common set of about 750 genes, many of which are known stress-responsive genes. Among the most highly enriched promoter elements in the induced gene set were heat-shock elements (HSEs), known motifs that change gene expression in response to high temperature in many systems. We show that HSEs from the promoter of the ASCORBATE PEROXIDASE 2 (APX2) gene were necessary and sufficient for APX2 expression in conditions of excess light, or under low light plus the herbicide. We tested APX2 expression phenotypes in overexpression and loss-of-function mutants of 15 Arabidopsis A-type heat-shock transcription factors (HSFs), and identified HSFA1D, HSFA2, and HSFA3 as key factors regulating APX2 expression in diverse stress conditions. Excess light regulates both the subcellular location of HSFA1D and its biochemical properties, making it a key early component of the excess light stress network of plants. PMID:23918368

Synthesis of the low molecular weight heat shock proteins in plants

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

Mansfield, M.A.; Key, J.L.

1987-08-01

Heat shock of living tissue induces the synthesis of a unique group of proteins, the heat shock proteins. In plants, the major group of heat shock proteins has a molecular mass of 15 to 25 kilodaltons. Accumulation to these proteins to stainable levels has been reported in only a few species. To examine accumulation of the low molecular weight heat shock proteins in a broader range of species, two-dimensional electrophoresis was used to resolve total protein from the following species: soybean (Glycine max L. Merr., var Wayne), pea (Pisum sativum L., var Early Alaska), sunflower (Helianthus annuus L.), wheat (Triticummore » asetivum L.), rice (Oryza sativa L., cv IR-36), maize (Zea mays L.), pearl millet (Pennisetum americanum L. Leeke, line 23DB), and Panicum miliaceum L. When identified by both silver staining and incorporation of radiolabel, a diverse array of low molecular weight heat shock proteins was synthesized in each of these species. These proteins accumulated to significant levels after three hours of heat shock but exhibited considerable heterogeneity in isoelectric point, molecular weight, stainability, and radiolabel incorporation. Although most appeared to be synthesized only during heat shock, some were detectable at low levels in control tissue. Compared to the monocots, a higher proportion of low molecular weight heat shock proteins was detectable in control tissues from dicots.« less

Infancy Parenting and Externalizing Psychopathology from Childhood through Adulthood: Developmental Trends

ERIC Educational Resources Information Center

Lorber, Michael F.; Egeland, Byron

2009-01-01

Developmental models and previous findings suggest that early parenting is more strongly associated with externalizing problems in early childhood than it is in adolescence. In this article, the authors address whether the association of poor-quality infancy parenting and externalizing problems "rebounds" in adulthood. Poor-quality infancy…

["Shock" therapies in Nazi Germany. The example of Berlin psychiatry].

PubMed

Rzesnitzek, L

2014-09-01

The idea that "shock" therapies were introduced by "Nazi-Psychiatry" very early and used radically in a cruel way darkens the image of these therapies until today. A case analysis of patient files of psychiatric hospitals in Berlin is used to recapitulate the introduction of insulin coma, metrazol and electroconvulsive therapy during the National Socialism era. Contrary to the false assumption that these "shock" therapies would have been introduced and preferred by psychiatrists involved with the Nazi regime and "euthanasia", in the case of Berlin these therapies were delayed by them and seldom used.

Microscale shock tube

NASA Astrophysics Data System (ADS)

Mirshekari, Gholamreza

This project aims at the simulation, design, fabrication and testing of a microscale shock tube. A step by step procedure has been followed to develop the different components of the microscale shock tube and then combine them together to realize the final device. The document reports on the numerical simulation of flows in a microscale shock tube, the experimental study of gas flow in microchannels, the design, microfabrication, and the test of a microscale shock tube. In the first step, a one-dimensional numerical model for simulation of transport effects at small-scale, appeared in low Reynolds number shock tubes is developed. The conservation equations have been integrated in the lateral directions and three-dimensional effects have been introduced as carefully controlled sources of mass, momentum and energy, into the one-dimensional model. The unsteady flow of gas behind the shock wave is reduced to a quasi-steady laminar flow solution, similar to the Blasius solution. The resulting one-dimensional equations are solved numerically and the simulations are performed for previously reported low Reynolds number shock tube experiments. Good agreement between the shock structure simulation and the attenuation due to the boundary layers has been observed. The simulation for predicting the performance of a microscale shock tube shows the large attenuation of shock wave at low pressure ratios. In the next step the steady flow inside microchannels has been experimentally studied. A set of microchannels with different geometries were fabricated. These microchannels have been used to measure the pressure drop as a function of flow rate in a steady compressible flow. The results of the experiments confirm that the flow inside the microscale shock tube follows the laminar model over the experiment's range of Knudsen number. The microscale shock tube is fabricated by deposition and patterning of different thin layers of selected materials on the silicon substrate. The direct

An experimental investigation of the impingement of a planar shock wave on an axisymmetric body at Mach 3

NASA Technical Reports Server (NTRS)

Brosh, A.; Kussoy, M. I.

1983-01-01

An experimental study of the flow caused by a planar shock wave impinging obliquely on a cylinder is presented. The complex three dimensional shock wave and boundary layer interaction occurring in practical problems, such as the shock wave impingement from the shuttle nose on an external fuel tank, and store carriage interference on a supersonic tactical aircraft were investigated. A data base for numerical computations of complex flows was also investigated. The experimental techniques included pressure measurements and oil flow patterns on the surface of the cylinder, and shadowgraphs and total and static pressure surveys on the leeward and windward planes of symmetry. The complete data is presented in tabular form. The results reveal a highly complex flow field with two separation zones, regions of high crossflow, and multiple reflected shocks and expansion fans.

Combination of Acute Physiology and Chronic Health Evaluation II score, early lactate area, and N-terminal prohormone of brain natriuretic peptide levels as a predictor of mortality in geriatric patients with septic shock.

PubMed

Wang, Hao; Li, Zhong; Yin, Mei; Chen, Xiao-Mei; Ding, Shi-Fang; Li, Chen; Zhai, Qian; Li, Yuan; Liu, Han; Wu, Da-Wei

2015-04-01

Given the high mortality rates in elderly patients with septic shock, the early recognition of patients at greatest risk of death is crucial for the implementation of early intervention strategies. Serum lactate and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels are often elevated in elderly patients with septic shock and are therefore important biomarkers of metabolic and cardiac dysfunction. We hypothesized that a risk stratification system that incorporates the Acute Physiology and Chronic Health Evaluation (APACHE) II score and lactate and NT-proBNP biomarkers would better predict mortality in geriatric patients with septic shock than the APACHE II score alone. A single-center prospective study was conducted from January 2012 to December 2013 in a 30-bed intensive care unit of a triservice hospital. The lactate area score was defined as the sum of the area under the curve of serial lactate levels measured during the 24 hours following admission divided by 24. The NT-proBNP score was assigned based on NT-proBNP levels measured at admission. The combined score was calculated by adding the lactate area and NT-proBNP scores to the APACHE II score. Multivariate logistic regression analyses and receiver operating characteristic curves were used to evaluate which variables and scoring systems served as the best predictors of mortality in elderly septic patients. A total of 115 patients with septic shock were included in the study. The overall 28-day mortality rate was 67.0%. When compared to survivors, nonsurvivors had significantly higher lactate area scores, NT-proBNP scores, APACHE II scores, and combined scores. In the multivariate regression model, the combined score, lactate area score, and mechanical ventilation were independent risk factors associated with death. Receiver operating characteristic curves indicated that the combined score had significantly greater predictive power when compared to the APACHE II score or the NT-proBNP score

Adapter for mounting a microphone flush with the external surface of the skin of a pressurized aircraft

NASA Technical Reports Server (NTRS)

Cohn, R. B. (Inventor)

1983-01-01

A mounting device for securing a microphone pick up head flush with respect to the external surfaces of the skin of an aircraft for detecting shock waves passing thereover is described. The mount includes a sleeve mounted internally of the aircraft for capturing and supporting an electronics package having the microphone pick up head attached thereto in a manner such that the head is flush with the external surface of the aircraft skin and a pressure seal is established between the internal and external surfaces of the aircraft skin.

Detrital shocked minerals: microstructural provenance indicators of impact craters

NASA Astrophysics Data System (ADS)

Cavosie, A. J.

2014-12-01

The study of detrital shocked minerals (DSMs) merges planetary science, sedimentology, mineralogy/crystallography, accessory mineral geochemistry, and geochronology, with the goal of identifying and determining provenance of shock metamorphosed sand grains. Diagnostic high-pressure impact-generated microstructures (planar fractures, planar deformation features) are readily identified on external grain surfaces using standard SEM imaging methods (BSE), and when found, unambiguously confirm an impact origin for a given sand grain. DSMs, including quartz, zircon, monazite, and apatite, have thus far been documented at the Vredefort Dome [1,2,3], Sudbury [4], Rock Elm [5], and Santa Fe [6,7] impact structures. DSMs have been identified in alluvium, colluvium, beach sand, and glacial deposits. Two main processes are recognized that imply the global siliciclastic record contains DSMs: they survive extreme distal transport, and they survive 'deep time' lithification. Distal transport: In South Africa, shocked minerals are preserved in alluvium from the Vaal River >750 km downstream from the Vredefort impact; SHRIMP U-Pb geochronology has confirmed the origin of detrital shocked zircon and monazite from shocked Vredefort bedrock [2]. Vredefort-derived shocked zircons have also been found at the mouth of the Orange River on the Atlantic coast, having travelled ~2000 km downriver from Vredefort [8]. Deep time preservation: Vredefort-derived shocked zircon and quartz has been documented in glacial diamictite from the 300 Myr-old Dwyka Group in South Africa. Shocked minerals were thus entrained and transported in Paleozoic ice sheets that passed over Vredefort [9]. An impact crater can thus be viewed as a unique 'point source', in some cases for billions of years [2,4]; DSMs thus have applications in studying eroded impact craters, sedimentary provenance, landscape evolution, and long-term sediment transport processes throughout the geologic record. This work was supported by

On the role of vasopressin and angiotensin in the development of irreversible haemorrhagic shock

PubMed Central

Errington, M. L.; e Silva, M. Rocha

1974-01-01

1. Long-lasting haemorrhagic hypotension (4·5 hr at 35 mmHg) leading to irreversible haemorrhagic shock, has been studied in normal dogs, in dogs treated with a bradykinin potentiating nonapeptide (BPP9a), which blocks the conversion of angiotensin I to angiotensin II, and in dogs with experimental chronic diabetes insipidus (DI dogs). BPP9a was given by I.V. injection before the start of bleeding (BPP pre-treated group), 45 min after blood pressure had reached 35 mmHg (BPP early treated group) or 2 hr after blood pressure had reached 35 mmHg (BPP late-treated group). After retransfusion of blood all dogs were allowed to recover and observed for a further period of 3 days. 2. Untreated control dogs developed haemorrhagic shock with tachycardia, low cardiac output, low total peripheral conductance and low stroke volume. All died within 24 hr of retransfusion, with pathological lesions typical of irreversible haemorrhagic shock. 3. BPP pre-treated dogs developed haemorrhagic shock with bradycardia (during early shock), high cardiac output, high peripheral vascular conductance and high stroke volume when compared with the untreated controls. All pre-treated animals survived the 3 day observation period. They were then killed and on post-mortem showed no signs of irreversible haemorrhagic shock. 4. BPP early-treated animals behaved like controls before BPP, but like pre-treated animals after the drug. Only one out of eight died within the 3 day observation period. 5. BPP late-treated dogs behaved like controls before BPP. They responded to the drug with a rise in cardiac output, peripheral vascular conductance and stroke volume, and with a fall in heart rate. These responses were, however, short-lived. Four out of these eight animals died within the 3 day observation period, with lesions of irreversible haemorrhagic shock. 6. DI dogs developed haemorrhagic shock with tachycardia (like controls), but with high cardiac output and peripheral vascular conductance (like

[Toxic shock syndrome].

PubMed

Tyll, T; Bílková, M; Revinová, A; Müller, M; Čurdová, M; Zlámal, M; Holub, M

2015-10-01

The authors present an up-to-date review of toxic shock syndrome (TSS) - a life-threatening condition where toxins of the Gram-positive bacteria Staphyloccocus aureus and Streptococcus pyogenes play a key role in the pathogenesis. The authors provide insight into the epidemiology and pathogenesis of the disease and point out the relevant patient history data and clinical signs and symptoms that may indicate progression of TSS. Last but not least, the state of the art diagnostic and therapeutic approaches to early and full blown TSS are summarized. Case reports are presented to illustrate two different etiological forms of this relatively rare nosological entity.

Physics of intermediate shocks: A review

NASA Technical Reports Server (NTRS)

Karimabadi, H.

1995-01-01

Intermediate shocks (ISs) lead to a transition from super-Alfvenic to sub-Alfvenic flow and are different from slow and fast shocks in that an IS rotates the component of the magnetic field tangent to the shock plane by 180 deg. Another peculiarity of ISs is that for the same upstream conditions an IS can have two different downstream states. There also exist a second class of ISs which rotate the magnetic field by an angle other than 180 deg. Due to their noncoplanar nature they cannot be time-stationary and are referred to as time-dependent intermediate shocks (TDIS). The existence of ISs has been the subject of much controversy over the years. Early studies questioned the physical reality of ISs. However, the studies of ISs found a new impetus when C.C. Wu showed that ISs do exist and are stable within the resistive MHD framework. In this paper, after a brief historical overview of the subject, we will review the latest developments in the study of ISs. In particular, we will address the questions of stability and structure of ISs and the relationship between ISs and other discontinuities. One of the recent developments has been the finding that ISs can be unsteady, reforming in time. Details of this process will be discussed. Finally, we examine the effect of anisotropy on the resolutions and discuss the relevance of ISs to the observed field rotations at the Earth's magnetopause.

Patterns of Sensitivity to Parenting and Peer Environments: Early Temperament and Adolescent Externalizing Behavior.

PubMed

Tung, Irene; Noroña, Amanda N; Morgan, Julia E; Caplan, Barbara; Lee, Steve S; Baker, Bruce L

2018-03-14

Although parenting behavior and friendship quality predict adolescent externalizing behaviors (EBs), individual differences in temperament may differentially affect susceptibility to these factors over time. In a multi-method and multi-informant study of 141 children followed prospectively from toddlerhood to adolescence, we tested the independent and interactive associations of age 3 reactive temperament (e.g., negative emotionality) and age 13 observed parenting (i.e., positive and negative behavior) and friendship (i.e., conflict and warmth), with multi-informant ratings of age 15 aggression and rule-breaking behavior. Negative parenting predicted growth in parent-rated EB, but only for adolescents with early reactive temperament. Temperament did not affect sensitivity to positive parenting or friendship. Results are discussed in the context of differential susceptibility theory and intervention implications for adolescents. © 2018 Society for Research on Adolescence.

The Coronal Analysis of SHocks and Waves (CASHeW) framework

NASA Astrophysics Data System (ADS)

Kozarev, Kamen A.; Davey, Alisdair; Kendrick, Alexander; Hammer, Michael; Keith, Celeste

2017-11-01

Coronal bright fronts (CBF) are large-scale wavelike disturbances in the solar corona, related to solar eruptions. They are observed (mostly in extreme ultraviolet (EUV) light) as transient bright fronts of finite width, propagating away from the eruption source location. Recent studies of individual solar eruptive events have used EUV observations of CBFs and metric radio type II burst observations to show the intimate connection between waves in the low corona and coronal mass ejection (CME)-driven shocks. EUV imaging with the atmospheric imaging assembly instrument on the solar dynamics observatory has proven particularly useful for detecting large-scale short-lived CBFs, which, combined with radio and in situ observations, holds great promise for early CME-driven shock characterization capability. This characterization can further be automated, and related to models of particle acceleration to produce estimates of particle fluxes in the corona and in the near Earth environment early in events. We present a framework for the coronal analysis of shocks and waves (CASHeW). It combines analysis of NASA Heliophysics System Observatory data products and relevant data-driven models, into an automated system for the characterization of off-limb coronal waves and shocks and the evaluation of their capability to accelerate solar energetic particles (SEPs). The system utilizes EUV observations and models written in the interactive data language. In addition, it leverages analysis tools from the SolarSoft package of libraries, as well as third party libraries. We have tested the CASHeW framework on a representative list of coronal bright front events. Here we present its features, as well as initial results. With this framework, we hope to contribute to the overall understanding of coronal shock waves, their importance for energetic particle acceleration, as well as to the better ability to forecast SEP events fluxes.

Fundamentals of collisionless shocks for astrophysical application, 2. Relativistic shocks

NASA Astrophysics Data System (ADS)

Bykov, A. M.; Treumann, R. A.

2011-08-01

In this concise review of the recent developments in relativistic shock theory in the Universe we restrict ourselves to shocks that do not exhibit quantum effects. On the other hand, emphasis is given to the formation of shocks under both non-magnetised and magnetised conditions. We only briefly discuss particle acceleration in relativistic shocks where much of the results are still preliminary. Analytical theory is rather limited in predicting the real shock structure. Kinetic instability theory is briefed including its predictions and limitations. A recent self-similar relativistic shock theory is described which predicts the average long-term shock behaviour to be magnetised and to cause reasonable power-law distributions for energetic particles. The main focus in this review is on numerical experiments on highly relativistic shocks in (i) pair and (ii) electron-nucleon plasmas and their limitations. These simulations do not validate all predictions of analytic and self-similar theory and so far they do not solve the injection problem and the self-modification by self-generated cosmic rays. The main results of the numerical experiments discussed in this review are: (i) a confirmation of shock evolution in non-magnetised relativistic plasma in 3D due to either the lepton-Weibel instability (in pair plasmas) or to the ion-Weibel instability; (ii) the sensitive dependence of shock formation on upstream magnetisation which causes suppression of Weibel modes for large upstream magnetisation ratios σ>10-3; (iii) the sensitive dependence of particle dynamics on the upstream magnetic inclination angle θ Bn , where particles of θ Bn >34° cannot escape upstream, leading to the distinction between `subluminal' and `superluminal' shocks; (iv) particles in ultra-relativistic shocks can hardly overturn the shock and escape to upstream; they may oscillate around the shock ramp for a long time, so to speak `surfing it' and thereby becoming accelerated by a kind of SDA; (v

Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube

NASA Astrophysics Data System (ADS)

Niegemann, P.; Fikri, M.; Wlokas, I.; Röder, M.; Schulz, C.

2018-05-01

Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.

Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube.

PubMed

Niegemann, P; Fikri, M; Wlokas, I; Röder, M; Schulz, C

2018-05-01

Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.

External fixation techniques for distal radius fractures.

PubMed

Capo, John T; Swan, Kenneth G; Tan, Virak

2006-04-01

Fractures of the distal radius are common injuries. Low-energy or high-energy mechanisms may be involved. Unstable distal radius fractures present a challenge to the treating orthopaedic surgeon. External fixation is a valuable instrument for fracture reduction and stabilization. Limited open incisions, early range of motion, and treatment of complex wounds are a few of the benefits of external fixation. Fixators may be spanning or nonbridging and may be used alone or in combination with other stabilization methods to obtain and maintain distal radius fracture reduction. Augmentation with percutaneous wires allows for optimal fracture stabilization with physiologic alignment of the wrist. Moderate distraction at the carpus does not induce postoperative stiffness. The distal radioulnar joint must be assessed and may need to be stabilized. Complications of external fixation are usually minor, but must be anticipated and treated early. Level V (expert opinion).

Validating a pragmatic definition of shock in adult patients presenting to the ED.

PubMed

Li, Yan-ling; Chan, Cangel Pui-yee; Sin, King-keung; Chan, Stewart S W; Lin, Pei-yi; Chen, Xiao-hui; Smith, Brendan E; Joynt, Gavin M; Graham, Colin A; Rainer, Timothy H

2014-11-01

The importance of the early recognition of shock in patients presenting to emergency departments is well recognized, but at present, there is no agreed practical definition for undifferentiated shock. The main aim of this study was to validate an a priori clinical definition of shock against 28-day mortality. This prospective, observational, cross-sectional, single-center study was conducted in Hong Kong, China. Data were collected between July 1, 2012, and January 31, 2013. An a priori definition of shock was designed, whereby patients admitted to the resuscitation room or high dependency area of the emergency department were divided into 1 of 3 groups-no shock, possible shock, and shock. The primary outcome was 28-day mortality. Secondary outcomes were in-hospital mortality or admission to the intensive or coronary care unit. A total of 111 patients (mean age, 67.2 ± 17.1 years; male = 69 [62%]) were recruited, of which 22 were classified as no shock, 54 as possible shock, and 35 as shock. Systolic blood pressure, mean arterial pressure, lactate, and base deficit correlated well with shock classifications (P < .05). Patients who had 3 or more positively defined shock variables had a 100% poor composite outcome rate (5 of 5). Patients with 2 shock variables had a 66.7% (4 of 6) poor composite outcome rate. A simple, practical definition of undifferentiated shock has been proposed and validated in a group of patients presenting to an emergency department in Hong Kong. This definition needs further validation in a larger population and other settings. Copyright © 2014 Elsevier Inc. All rights reserved.

Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome.

PubMed

Nasa, Prashant; Sehrawat, Deepak; Kansal, Sudha; Chawla, Rajesh

2010-07-01

Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS.

A probabilistic method to establish the reliability of carbon-carbon rocket motor nozzles. Volume 3: Stress and reliability analysis of layered composite cylinders under thermal shock

NASA Astrophysics Data System (ADS)

Heller, R. A.; Thangjitham, S.; Wang, X.

1992-04-01

The state of stress in a cylindrical structure consisting of multiple layers of carbon-carbon composite and subjected to thermal and pressure shock are analyzed using an elasticity approach. The reliability of the structure based on the weakest link concept and the Weibull distribution is also calculated. Coupled thermo-elasticity is first assumed and is shown to be unnecessary for the material considered. The effects of external and internal thermal shock as well as a superimposed pressure shock are examined. It is shown that for the geometry chosen, the structure may fail when exposed to thermal shock alone while a superimposed pressure shock can mitigate the probability of failure.

An Imbalance of Approach and Effortful Control Predicts Externalizing Problems: Support for Extending the Dual-Systems Model into Early Childhood.

PubMed

Jonas, Katherine; Kochanska, Grazyna

2018-01-25

Although the association between deficits in effortful control and later externalizing behavior is well established, many researchers (Nigg Journal of Child Psychology and Psychiatry, 47(3-4), 395-422, 2006; Steinberg Developmental Review, 28(1), 78-106, 2008) have hypothesized this association is actually the product of the imbalance of dual systems, or two underlying traits: approach and self-regulation. Very little research, however, has deployed a statistically robust strategy to examine that compelling model; further, no research has done so using behavioral measures, particularly in longitudinal studies. We examined the imbalance of approach and self-regulation (effortful control, EC) as predicting externalizing problems. Latent trait models of approach and EC were derived from behavioral measures collected from 102 children in a community sample at 25, 38, 52, and 67 months (2 to 5 ½ years), and used to predict externalizing behaviors, modeled as a latent trait derived from parent-reported measures at 80, 100, 123, and 147 months (6 ½ to 12 years). The imbalance hypothesis was supported: Children with an imbalance of approach and EC had more externalizing behavior problems in middle childhood and early preadolescence, relative to children with equal levels of the two traits.

Global Aeroheating Measurements of Shock-Shock Interactions on a Swept Cylinder

NASA Technical Reports Server (NTRS)

Mason, Michelle L.; Berry, Scott A.

2015-01-01

The effects of fin leading-edge radius and sweep angle on peak heating rates due to shock-shock interactions were investigated in the NASA Langley Research Center 20-Inch Mach 6 Air Tunnel. The cylindrical leading-edge fin models, with radii varied from 0.25 to 0.75 inches, represent wings or struts on hypersonic vehicles. A 9deg wedge generated a planar oblique shock at 16.7deg. to the flow that intersected the fin bow shock, producing a shock-shock interaction that impinged on the fin leading edge. The fin sweep angle was varied from 0deg (normal to the free-stream) to 15deg and 25deg swept forward. These cases were chosen to explore three characterized shock-shock interaction types. Global temperature data were obtained from the surface of the fused silica fins using phosphor thermography. Metal oil flow models with the same geometries as the fused silica models were used to visualize the streamline patterns for each angle of attack. High-speed zoom-schlieren videos were recorded to show the features and any temporal unsteadiness of the shock-shock interactions. The temperature data were analyzed using a one-dimensional semi-infinite method, as well as one- and two-dimensional finite-volume methods. These results were compared to determine the proper heat transfer analysis approach to minimize errors from lateral heat conduction due to the presence of strong surface temperature gradients induced by the shock interactions. The general trends in the leading-edge heat transfer behavior were similar for each explored shock-shock interaction type regardless of the leading-edge radius. However, the dimensional peak heat transfer coefficient augmentation increased with decreasing leading-edge radius. The dimensional peak heat transfer output from the two-dimensional code was about 20% higher than the value from a standard, semi-infinite one-dimensional method.

Shock temperature measurement of transparent materials under shock compression

NASA Astrophysics Data System (ADS)

Hu, Jinbiao

1999-06-01

Under shock compression, some materials have very small absorptance. So it's emissivity is very small too. For this kinds of materials, although they stand in high temperature state under shock compression, the temperature can not be detected easily by using optical radiation technique because of the low emissivity. In this paper, an optical radiation temperature measurement technique of measuring temperature of very low emissive material under shock compression was proposed. For making sure this technique, temperature of crystal NaCl at shock pressure 41 GPa was measured. The result agrees with the results of Kormer et al and Ahrens et al very well. This shows that this technique is reliable and can be used to measuring low emissive shock temperature.

Toxic Shock Syndrome: Still a Timely Diagnosis.

PubMed

Gossack-Keenan, Kira L; Kam, April J

2017-10-16

Toxic shock syndrome (TSS) is an acute, severe, toxin-mediated disease, characterized by fever, hypotension, and multiorgan system involvement. Toxic shock syndrome has made headlines because of its high associated morbidity and mortality rate in previously healthy young females. Incidence peaked in the early 1980s owing to increased usage of ultra-absorbent tampons. After improved patient education and tampon labeling, the incidence of menstrual TSS has declined. A previously healthy 14-year-old girl presented to an urgent care center with a 2-day history of fever, erythematous maculopapular rash, vomiting, diarrhea, and malaise. She was found to be tachycardic and hypotensive. Investigations revealed thrombocytopenia, an elevated white count and lactate, and acute kidney injury, consistent with septic shock. Recent tampon usage with menstruation was reported, and a pelvic examination revealed purulent vaginal discharge. The patient was transferred to a pediatric intensive care unit for antibiotic and vasopressor therapy. Vaginal swabs later tested positive for Staphylococcus aureus and TSS toxin-1. Although the incidence of TSS has decreased in recent years, it is crucial that clinicians rapidly recognize and treat this life-threatening condition. Emergency physicians should always have a high index of suspicion for TSS in young females presenting without another obvious cause of shock. A pelvic examination should always be completed in these cases.

Diagnostic Accuracy of Commercially Available Automated External Defibrillators.

PubMed

Nishiyama, Takahiko; Nishiyama, Ako; Negishi, Masachika; Kashimura, Shin; Katsumata, Yoshinori; Kimura, Takehiro; Nishiyama, Nobuhiro; Tanimoto, Yoko; Aizawa, Yoshiyasu; Mitamura, Hideo; Fukuda, Keiichi; Takatsuki, Seiji

2015-12-01

Although automated external defibrillators (AEDs) have contributed to a better survival of out-of-hospital cardiac arrests, there have been reports of their malfunctioning. We investigated the diagnostic accuracy of commercially available AEDs using surface ECGs of ventricular fibrillation (VF), ventricular tachycardia (VT), and supraventricular tachycardia (SVT). ECGs(VF 31, VT 48, SVT 97) were stored during electrophysiological studies and transmitted to 4 AEDs, the LifePak CR Plus (CR Plus), HeartStart FR3 (FR3), and CardioLife AED-2150 (CL2150) and -9231 (CL9231), through the pad electrode cables. For VF, the CL2150 and CL9231 advised shocks in all cases, and the CR Plus and FR3 advised shocks in all but one VF case. For VTs faster than 180 bpm, the ratios for advising shocks were 79%, 36%, 89%, and 96% for the CR Plus, FR3, CL2150, and CL9231, respectively. The FR3 and CR Plus did not advise shocks for narrow QRS SVTs, whereas the CL9231 tended to treat high-rate tachycardias faster than 180 bpm even with narrow QRS complexes. The characteristics of the shock advice for the FR3 differed from that for the CL9231 (kappa coefficient [κ]=0.479, P<0.001), and the CR Plus and CL2150 had characteristics somewhere between the 2 former AEDs (κ=0.818, P<0.001). Commercially available AEDs diagnosed VF almost always correctly. For VT and SVT diagnoses, a discrepancy was evident among the 4 investigated AEDs. The differences in the arrhythmia diagnosis algorithms for differentiating SVT from VT were thought to account for these differences. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

PLANETARY EMBRYO BOW SHOCKS AS A MECHANISM FOR CHONDRULE FORMATION

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

Mann, Christopher R.; Boley, Aaron C.; Morris, Melissa A.

2016-02-20

We use radiation hydrodynamics with direct particle integration to explore the feasibility of chondrule formation in planetary embryo bow shocks. The calculations presented here are used to explore the consequences of a Mars-size planetary embryo traveling on a moderately excited orbit through the dusty, early environment of the solar system. The embryo’s eccentric orbit produces a range of supersonic relative velocities between the embryo and the circularly orbiting gas and dust, prompting the formation of bow shocks. Temporary atmospheres around these embryos, which can be created via volatile outgassing and gas capture from the surrounding nebula, can non-trivially affect thermalmore » profiles of solids entering the shock. We explore the thermal environment of solids that traverse the bow shock at different impact radii, the effects that planetoid atmospheres have on shock morphologies, and the stripping efficiency of planetoidal atmospheres in the presence of high relative winds. Simulations are run using adiabatic and radiative conditions, with multiple treatments for the local opacities. Shock speeds of 5, 6, and 7 km s{sup −1} are explored. We find that a high-mass atmosphere and inefficient radiative conditions can produce peak temperatures and cooling rates that are consistent with the constraints set by chondrule furnace studies. For most conditions, the derived cooling rates are potentially too high to be consistent with chondrule formation.« less

Proceedings of the 15th International Symposium on Shock Waves and Shock Tubes

NASA Astrophysics Data System (ADS)

Bershader, Daniel; Hanson, Ronald

1986-09-01

One hundred ten papers were presented in 32 sessions. Topics included: The application of Hook-method spectroscopy to the diagnosis of shock-heated gases. The nonintrusive destruction of kidney stones by underwater focused shock waves. Several of the papers reflect the recent and continuing interest in shock wave phenomena in dusty gases and other multiphase and heterogeneous systems, including chemically reactive configurations. The major subject areas were: shock propagation and interactions; shock-general chemical kinetics; shock computation, modeling, and stability problems; shock wave aerodynamics; experimental methods; shocks in multiphase and heterogeneous media; high energy gas excitation and wave phenomena; and technical applications and shocks in condensed matter.

Shock, Post-Shock Annealing, and Post-Annealing Shock in Ureilites

NASA Technical Reports Server (NTRS)

Rubin, Alan E.

2006-01-01

The thermal and shock histories of ureilites can be divided into four periods: 1) formation, 2) initial shock, 3) post-shock annealing, and 4) post-annealing shock. Period 1 occurred approx.4.55 Ga ago when ureilites formed by melting chondritic material. Impact events during period 2 caused silicate darkening, undulose to mosaic extinction in olivines, and the formation of diamond, lonsdaleite, and chaoite from indigenous carbonaceous material. Alkali-rich fine-grained silicates may have been introduced by impact injection into ureilites during this period. About 57% of the ureilites were unchanged after period 2. During period 3 events, impact-induced annealing caused previously mosaicized olivine grains to become aggregates of small unstrained crystals. Some ureilites experienced reduction as FeO at the edges of olivine grains reacted with C from the matrix. Annealing may also be responsible for coarsening of graphite in a few ureilites, forming euhedral-appearing, idioblastic crystals. Orthopyroxene in Meteorite Hills (MET) 78008 may have formed from pigeonite by annealing during this period. The Rb-Sr internal isochron age of approx.4.0 Ga for MET 78008 probably dates the annealing event. At this late date, impacts are the only viable heat source. About 36% of ureilites experienced period 3 events, but remained unchanged afterwards. During period 4, approx.7% of the ureilites were shocked again, as is evident in the polymict breccia, Elephant Moraine (EET) 83309. This rock contains annealed mosaicized olivine aggregates composed of small individual olivine crystals that exhibit undulose extinction. Ureilites may have formed by impact-melting chondritic material on a primitive body with heterogeneous O isotopes. Plagioclase was preferentially lost from the system due to its low impedance to shock compression. Brief melting and rapid burial minimized the escape of planetary-type noble gases from the ureilitic melts. Incomplete separation of metal from silicates

3D multicellular model of shock wave-cell interaction.

PubMed

Li, Dongli; Hallack, Andre; Cleveland, Robin O; Jérusalem, Antoine

2018-05-01

Understanding the interaction between shock waves and tissue is critical for ad- vancing the use of shock waves for medical applications, such as cancer therapy. This work aims to study shock wave-cell interaction in a more realistic environment, relevant to in vitro and in vivo studies, by using 3D computational models of healthy and cancerous cells. The results indicate that for a single cell embedded in an extracellular environment, the cellular geometry does not influence significantly the membrane strain but does influence the von Mises stress. On the contrary, the presence of neighbouring cells has a strong effect on the cell response, by increasing fourfold both quantities. The membrane strain response of a cell converges with more than three neighbouring cell layers, indicating that a cluster of four layers of cells is sufficient to model the membrane strain in a large domain of tissue. However, a full 3D tissue model is needed if the stress evaluation is of main interest. A tumour mimicking multicellular spheroid model is also proposed to study mutual interaction between healthy and cancer cells and shows that cancer cells can be specifically targeted in an early stage tumour-mimicking environment. This work presents 3D computational models of shock-wave/cell interaction in a biophysically realistic environment using real cell morphology in tissue-mimicking phantom and multicellular spheroid. Results show that cell morphology does not strongly influence the membrane strain but influences the von Mises stress. While the presence of neighbouring cells significantly increases the cell response, four cell layers are enough to capture the membrane strain change in tissue. However, a full tissue model is necessary if accurate stress analysis is needed. The work also shows that cancer cells can be specifically targetted in early stage tumourmimicking environment. This work is a step towards realistic modelling of shock-wave/cell interactions in tissues and

Calculation of external-internal flow fields for mixed-compression inlets

NASA Technical Reports Server (NTRS)

Chyu, W. J.; Kawamura, T.; Bencze, D. P.

1986-01-01

Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

Calculation of external-internal flow fields for mixed-compression inlets

NASA Technical Reports Server (NTRS)

Chyu, W. J.; Kawamura, T.; Bencze, D. P.

1987-01-01

Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

Galaxy collisions and shocks in compact groups

NASA Astrophysics Data System (ADS)

O'Sullivan, Ewan

2017-09-01

Evidence from IR, X-ray and HI studies suggests that low mass compact groups represent a key evolutionary stage in which shocks caused by galaxy interactions drive both the transformation of gas-rich spirals into early-type galaxies, and the build-up of the hot IGM. We have selected five groups where extensive multi-wavelength data shows violent ongoing galaxy interactions. We now propose to observe them with Chandra and XMM, searching for or confirming the presence of shocks in the X-ray IGM, measuring their strength and ability to heat cold gas, and examining the impact of galaxy/IGM interactions on galaxy transformation. Combined with our IR, CO, HI and optical IFU data, these observations will provide an exceptionally detailed view of this critical stage of galaxy and group evolution.

Shock & Anaphylactic Shock. Learning Activity Package.

ERIC Educational Resources Information Center

Hime, Kirsten

This learning activity package on shock and anaphylactic shock is one of a series of 12 titles developed for use in health occupations education programs. Materials in the package include objectives, a list of materials needed, information sheets, reviews (self evaluations) of portions of the content, and answers to reviews. These topics are…

α-Crystallins Are Small Heat Shock Proteins: Functional and Structural Properties.

PubMed

Tikhomirova, T S; Selivanova, O M; Galzitskaya, O V

2017-02-01

During its life cycle, a cell can be subjected to various external negative effects. Many proteins provide cell protection, including small heat shock proteins (sHsp) that have chaperone-like activity. These proteins have several important functions involving prevention of apoptosis and retention of cytoskeletal integrity; also, sHsp take part in the recovery of enzyme activity. The action mechanism of sHsp is based on the binding of hydrophobic regions exposed to the surface of a molten globule. α-Crystallins presented in chordate cells as two αA- and αB-isoforms are the most studied small heat shock proteins. In this review, we describe the main functions of α-crystallins, features of their secondary and tertiary structures, and examples of their partners in protein-protein interactions.

PSR J2124-3358: A Bow Shock Nebula with an X-ray Tail

NASA Astrophysics Data System (ADS)

Chatterjee, S.; Gaensler, B. M.; Vigelius, M.; Cordes, J. M.; Arzoumanian, Z.; Stappers, B.; Ghavamian, P.; Melatos, A.

2005-12-01

As neutron stars move supersonically through the interstellar medium, their relativistic winds are confined by the ram pressure of the interstellar medium. The outer shocked layers may emit in Hα , producing a visible bow shock nebula, while the confined relativistic wind may produce radio or X-ray emission. The Hα bow shock nebula powered by the recycled pulsar J2124-3358 is asymmetric about the velocity vector and shows a marked kink. In recent observations with the Chandra X-ray Observatory, we have detected a long, curved X-ray tail associated with the pulsar. The tail is not aligned with the pulsar velocity, but is confined within the optical bow shock. The X-ray spectrum of the tail is well-fit by a power law, consistent with synchrotron emission from the wind termination shock and the post-shock flow. The presence of Hα and X-ray emission allows us to trace both the external ambient medium and the confined wind. In magnetohydrodynamic simulations, we verify that a bulk flow and non-uniformities in the ambient medium can produce the observed shape of the nebula, possibly in combination with an anisotropic pulsar wind. Support for this work was provided by the National Aeronautics and Space Administration through Chandra Award Number GO5-6075X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of the National Aeronautics Space Administration under contract NAS8-03060.

Effects of Atwood number on shock focusing in shock-cylinder interaction

NASA Astrophysics Data System (ADS)

Ou, Junfeng; Ding, Juchun; Luo, Xisheng; Zhai, Zhigang

2018-02-01

The evolution of shock-accelerated heavy-gas cylinder surrounded by the air with different Atwood numbers (A_t=0.28, 0.50, 0.63) is investigated, concentrating on shock focusing and jet formation. Experimentally, a soap film technique is used to generate an ideal two-dimensional discontinuous gas cylinder with a clear surface, which can guarantee the observation of shock wave movements inside the cylinder. Different Atwood numbers are realized by different mixing ratios of SF_6 and air inside the cylinder. A high-speed schlieren system is adopted to capture the shock motions and jet morphology. Numerical simulations are also performed to provide more information. The results indicate that an inward jet is formed for low Atwood numbers, while an outward jet is generated for high Atwood numbers. Different Atwood numbers will lead to the differences in the relative velocities between the incident shock and the refraction shock, which ultimately results in the differences in shock competition near the downstream pole. The morphology and feature of the jet are closely associated with the position and intensity of shock focusing. The pressure and vorticity contours indicate that the jet formation should be attributed to the pressure pulsation caused by shock focusing, and the jet development is ascribed to the vorticity induction. Finally, a time ratio proposed in the previous work for determining the shock-focusing type is verified by experiments.

Investigation of Inlet Control Parameters for an External-internal-compression Inlet from Mach 2.1 to 3.0

NASA Technical Reports Server (NTRS)

Anderson, B. H.; Bowditch, D. N.

1958-01-01

Investigation of the control parameters of an external-internal compression inlet indicates that the cowl-lip shock provides a signal to position the spike and to start the inlet over a Mach number range from 2.1 to 3.0. Use of a single fixed probe position to control the spike over the range of conditions resulted in a 3.7-count loss in total-pressure recovery at Mach 3.0 and 0 deg angle of attack. Three separate shock-sensing-probe positions were required to set the spike for peak recovery from Mach 2.1 to 3.0 and angles of attack from 0 deg to 6 deg. When the inlet was unstarted, an erroneous signal was obtained from the normal-shock control through most of the starting cycle that prevented the inlet from starting. Therefore, it was necessary to over-ride the normal-shock control signal and not allow the control to position the terminal shock until the spike was positioned.

Modeling of plasticity and fracture of metals at shock loading

NASA Astrophysics Data System (ADS)

Mayer, A. E.; Khishchenko, K. V.; Levashov, P. R.; Mayer, P. N.

2013-05-01

In this paper, we present a model of dislocation plasticity and fracture of metals, which in combination with the wide-range equation of state and the continuum mechanics equations is a necessary component for simulation of the shock-wave loading. We take into account immobilization of dislocations and nucleation of micro-voids in weakened zones of substance; this is distinguished feature of the present version of the model. Accounting of the dislocations immobilization provides a better description of the unloading wave structure, while the detailed consideration of processes in the weakened zones expands the domain of applicability of fracture model to higher strain rates. We compare our results with the experimental data for the shock loading of aluminum, copper, and nickel samples; the comparison indicates satisfactory description of the elastic precursor, unloading wave, and spall pulse. Using the model, we investigate intently the early stage of the shock formation in solids; it is found out that the elastic precursor is formed even for a strong shock wave, and initially the precursor has very large amplitude and propagation velocity.

Ion Ramp Structure of Bow shocks and Interplanetary Shocks: Differences and Similarities

NASA Astrophysics Data System (ADS)

Goncharov, O.; Safrankova, J.; Nemecek, Z.; Koval, A.; Szabo, A.; Prech, L.; Zastenker, G. N.; Riazantseva, M.

2017-12-01

Collisionless shocks play a significant role in the solar wind interaction with the Earth. Fast forward shocks driven by coronal mass ejections or by interaction of fast and slow solar wind streams can be encountered in the interplanetary space, whereas the bow shock is a standing fast reverse shock formed by an interaction of the supersonic solar wind with the Earth magnetic field. Both types of shocks are responsible for a transformation of a part of the energy of the directed solar wind motion to plasma heating and to acceleration of reflected particles to high energies. These processes are closely related to the shock front structure. In present paper, we compares the analysis of low-Mach number fast forward interplanetary shocks registered in the solar wind by the DSCOVR, WIND, and ACE with observations of bow shock crossings observed by the Cluster, THEMIS, MMS, and Spektr-R spacecraft. An application of the high-time resolution data facilitates further discussion on formation mechanisms of both types of shocks.

The Dynamics of Internalizing and Externalizing Comorbidity Across the Early School Years

PubMed Central

Willner, Cynthia J.; Gatzke-Kopp, Lisa M.; Bray, Bethany C.

2017-01-01

High rates of comorbidity are observed between internalizing and externalizing problems, yet the developmental dynamics of comorbid symptom presentations are not yet well understood. This study explored the developmental course of latent profiles of internalizing and externalizing symptoms across kindergarten, 1st, and 2nd grade. The sample consisted of 336 children from an urban, low-income community, selected based on relatively high (61%) or low (39%) aggressive/oppositional behavior problems at school entry (64% male; 70% African American, 20% Hispanic). Teachers reported on children’s symptoms in each year. An exploratory latent profile analysis of children’s scores on aggression/oppositionality, hyperactivity/inattention, anxiety, and social withdrawal symptom factors revealed 4 latent symptom profiles: comorbid (48% of the sample in each year), internalizing (19–23%), externalizing (21–22%), and well-adjusted (7–11%). The developmental course of these symptom profiles was examined using a latent transition analysis, which revealed remarkably high continuity in the comorbid symptom profile (89% from one year to the next) and moderately high continuity in both the internalizing and externalizing profiles (80% and 71%, respectively). Internalizing children had a 20% probability of remitting to the well-adjusted profile by the following year, whereas externalizing children had a 25% probability of transitioning to the comorbid profile. These results are consistent with the hypothesis that a common vulnerability factor contributes to developmentally stable internalizing-externalizing comorbidity, while also suggesting that some children with externalizing symptoms are at risk for subsequently accumulating internalizing symptoms. PMID:27739391

Not Just Fresh and Altered Basalt: Shocked Soil and Shocked Baked Zones Show the Collective Effects of Alteration and Shock

NASA Astrophysics Data System (ADS)

Wright, S. P.

2017-07-01

Besides shocked versions of both fresh and several types of altered basalt, shocked soils and baked zones found in Lonar Crater ejecta are examined to unravel the combined effects of alteration, shock, and then post-shock alteration of impact glass.

Fatal streptococcal toxic shock syndrome from an intrauterine device.

PubMed

Cho, Elizabeth E; Fernando, Dinali

2013-04-01

The occurrence of toxic shock syndrome from an intrauterine device (IUD) is very rare. To raise awareness of the risk of toxic shock syndrome caused by an IUD, to educate others about when to suspect this complication, and to provide treatment recommendations. A 49-year-old woman presented to the Emergency Department in septic shock after complaining of 5 days of nausea, vomiting, and diarrhea. Physical examination findings included a diffusely tender and rigid abdomen with free fluid on bedside sonogram. She was found, on computed tomography of her abdomen and pelvis, to have an IUD with moderate ascites. The IUD was removed, and both her IUD and her blood cultures grew out group A Streptococcus. Despite aggressive medical management, which included multiple vasopressors and broad-spectrum antibiotics, she died from group A streptococcal sepsis, with the IUD as her most likely source. Her clinical presentation and laboratory findings meet the Centers for Disease Control and Prevention diagnostic criteria for streptococcal toxic shock syndrome. Her diagnosis was confirmed by autopsy. IUDs should be considered as a possible source of infection in patients with an IUD who present with symptoms consistent with toxic shock syndrome. These patients need to be aggressively managed with early surgical intervention. Copyright © 2013. Published by Elsevier Inc.

Early changes in microbial colonization selectively modulate intestinal enzymes, but not inducible heat shock proteins in young adult Swine.

PubMed

Arnal, Marie-Edith; Zhang, Jing; Messori, Stefano; Bosi, Paolo; Smidt, Hauke; Lallès, Jean-Paul

2014-01-01

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but also

Early Changes in Microbial Colonization Selectively Modulate Intestinal Enzymes, but Not Inducible Heat Shock Proteins in Young Adult Swine

PubMed Central

Arnal, Marie-Edith; Zhang, Jing; Messori, Stefano; Bosi, Paolo; Smidt, Hauke; Lallès, Jean-Paul

2014-01-01

Metabolic diseases and obesity are developing worldwide in a context of plethoric intake of high energy diets. The intestine may play a pivotal role due to diet-induced alterations in microbiota composition and increased permeability to bacterial lipopolysaccharide inducing metabolic inflammation. Early programming of metabolic disorders appearing in later life is also suspected, but data on the intestine are lacking. Therefore, we hypothesized that early disturbances in microbial colonization have short- and long-lasting consequences on selected intestinal components including key digestive enzymes and protective inducible heat shock proteins (HSP). The hypothesis was tested in swine offspring born to control mothers (n = 12) or mothers treated with the antibiotic amoxicillin around parturition (n = 11), and slaughtered serially at 14, 28 and 42 days of age to assess short-term effects. To evaluate long-term consequences, young adult offspring from the same litters were offered a normal or a fat-enriched diet for 4 weeks between 140 and 169 days of age and were then slaughtered. Amoxicillin treatment transiently modified both mother and offspring microbiota. This was associated with early but transient reduction in ileal alkaline phosphatase, HSP70 (but not HSP27) and crypt depth, suggesting a milder or delayed intestinal response to bacteria in offspring born to antibiotic-treated mothers. More importantly, we disclosed long-term consequences of this treatment on jejunal alkaline phosphatase (reduced) and jejunal and ileal dipeptidylpeptidase IV (increased and decreased, respectively) of offspring born to antibiotic-treated dams. Significant interactions between early antibiotic treatment and later diet were observed for jejunal alkaline phosphatase and sucrase. By contrast, inducible HSPs were not affected. In conclusion, our data suggest that early changes in bacterial colonization not only modulate intestinal architecture and function transiently, but

Involvement of the Sieve Element Cytoskeleton in Electrical Responses to Cold Shocks1[W

PubMed Central

Hafke, Jens B.; Ehlers, Katrin; Föller, Jens; Höll, Sabina-Roxana; Becker, Stefanie; van Bel, Aart J.E.

2013-01-01

This study dealt with the visualization of the sieve element (SE) cytoskeleton and its involvement in electrical responses to local cold shocks, exemplifying the role of the cytoskeleton in Ca2+-triggered signal cascades in SEs. High-affinity fluorescent phalloidin as well as immunocytochemistry using anti-actin antibodies demonstrated a fully developed parietal actin meshwork in SEs. The involvement of the cytoskeleton in electrical responses and forisome conformation changes as indicators of Ca2+ influx was investigated by the application of cold shocks in the presence of diverse actin disruptors (latrunculin A and cytochalasin D). Under control conditions, cold shocks elicited a graded initial voltage transient, ΔV1, reduced by external La3+ in keeping with the involvement of Ca2+ channels, and a second voltage transient, ΔV2. Cytochalasin D had no effect on ΔV1, while ΔV1 was significantly reduced with 500 nm latrunculin A. Forisome dispersion was triggered by cold shocks of 4°C or greater, which was indicative of an all-or-none behavior. Forisome dispersion was suppressed by incubation with latrunculin A. In conclusion, the cytoskeleton controls cold shock-induced Ca2+ influx into SEs, leading to forisome dispersion and sieve plate occlusion in fava bean (Vicia faba). PMID:23624858

Inverse Bremsstrahlung in Shocked Astrophysical Plasmas

NASA Technical Reports Server (NTRS)

Baring, Matthew G.; Jones, Frank C.; Ellison, Donald C.

2000-01-01

There has recently been interest in the role of inverse bremsstrahlung, the emission of photons by fast suprathermal ions in collisions with ambient electrons possessing relatively low velocities, in tenuous plasmas in various astrophysical contexts. This follows a long hiatus in the application of suprathermal ion bremsstrahlung to astrophysical models since the early 1970s. The potential importance of inverse bremsstrahlung relative to normal bremsstrahlung, i.e. where ions are at rest, hinges upon the underlying velocity distributions of the interacting species. In this paper, we identify the conditions under which the inverse bremsstrahlung emissivity is significant relative to that for normal bremsstrahlung in shocked astrophysical plasmas. We determine that, since both observational and theoretical evidence favors electron temperatures almost comparable to, and certainly not very deficient relative to proton temperatures in shocked plasmas, these environments generally render inverse bremsstrahlung at best a minor contributor to the overall emission. Hence inverse bremsstrahlung can be safely neglected in most models invoking shock acceleration in discrete sources such as supernova remnants. However, on scales approximately > 100 pc distant from these sources, Coulomb collisional losses can deplete the cosmic ray electrons, rendering inverse bremsstrahlung, and perhaps bremsstrahlung from knock-on electrons, possibly detectable.

Bone scanning in severe external otitis

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

Levin, W.J.; Shary, J.H. 3d.; Nichols, L.T.

1986-11-01

Technetium99 Methylene Diphosphate bone scanning has been considered an early valuable tool to diagnose necrotizing progressive malignant external otitis. However, to our knowledge, no formal studies have actually compared bone scans of otherwise young, healthy patients with severe external otitis to scans of patients with clinical presentation of malignant external otitis. Twelve patients with only severe external otitis were studied with Technetium99 Diphosphate and were compared to known cases of malignant otitis. All scans were evaluated by two neuroradiologists with no prior knowledge of the clinical status of the patients. Nine of the 12 patients had positive bone scans withmore » many scans resembling those reported with malignant external otitis. Interestingly, there was no consistent correlation between the severity of clinical presentation and the amount of Technetium uptake. These findings suggest that a positive bone scan alone should not be interpreted as indicative of malignant external otitis.« less

Toxic Shock Syndrome: An Unusual Organism.

PubMed

Young, Katie; Luni, Faraz Khan; Yoon, Youngsook

2016-07-01

Streptococcal toxic shock syndrome is a rapidly fatal disease causing hypotension with multi organ dysfunction (MODS) early in the course of infection, which by definition is caused by Group A streptococcus (GAS). We describe a case of Toxic Shock like Syndrome (TSLS) in which the causative organism was not a GAS. A 71-year-old woman with hepatitis C and primary biliary cirrhosis had sudden onset of slurred speech and left arm and facial numbness. She had bilateral erythematous macular rash present on the flanks and legs. She was started on empiric antibiotics but her condition rapidly deteriorated 6 hours after admission. During this time, the development of multiple large reddish-pink areas of ecchymosis with bullae on her lower extremities, flanks, and groin were noted. She also developed multiorgan dysfunction (MODS) with renal dysfunction, coagulopathy and liver involvement. Patient expired before surgery could be performed and the time from presentation to the time of death was 16 hours. The blood and bullae fluid cultures grew Streptococcus dysgalactiae equisimilis. Streptococcus dysgalactiae equisimilis is a rare cause of TSLS which typically affects elderly or immunocompromised patients and only a few cases have been described in the literature. Our patient met criteria for TSLS which caused rapid shock and MODS. We review the literature of the cases describing the clinical characteristics of TSLS cause by non-GAS. Group G Streptococci is a rare but lethal cause of streptococcal toxic shock syndrome. Copyright © 2016 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

Imbalances in serum angiopoietin concentrations are early predictors of septic shock development in patients with post chemotherapy febrile neutropenia

PubMed Central

2010-01-01

Background Febrile neutropenia carries a high risk of sepsis complications, and the identification of biomarkers capable to identify high risk patients is a great challenge. Angiopoietins (Ang -) are cytokines involved in the control microvascular permeability. It is accepted that Ang-1 expression maintains endothelial barrier integrity, and that Ang-2 acts as an antagonizing cytokine with barrier-disrupting functions in inflammatory situations. Ang-2 levels have been recently correlated with sepsis mortality in intensive care units. Methods We prospectively evaluated concentrations of Ang-1 and Ang-2 at different time-points during febrile neutropenia, and explored the diagnostic accuracy of these mediators as potential predictors of poor outcome in this clinical setting before the development of sepsis complications. Results Patients that evolved with septic shock (n = 10) presented higher levels of Ang-2 measured 48 hours after fever onset, and of the Ang-2/Ang-1 ratio at the time of fever onset compared to patients with non-complicated sepsis (n = 31). These levels correlated with sepsis severity scores. Conclusions Our data suggest that imbalances in the concentrations of Ang-1 and Ang-2 are independent and early markers of the risk of developing septic shock and of sepsis mortality in febrile neutropenia, and larger studies are warranted to validate their clinical usefulness. Therapeutic strategies that manipulate this Ang-2/Ang-1 imbalance can potentially offer new and promising treatments for sepsis in febrile neutropenia. PMID:20509945

Heat shock during early somitogenesis induces caudal vertebral column defects in Atlantic salmon (Salmo salar).

PubMed

Wargelius, Anna; Fjelldal, Per Gunnar; Hansen, Tom

2005-07-01

In several terrestrial vertebrates, heat shock (HS) during somitogenesis causes vertebral deformities. To determine if vertebral deformities can occur due to sudden temperature changes during early development in fish, Atlantic salmon embryos were HS treated during somitogenesis. Ten months later these individuals displayed a high prevalence of caudal vertebral column condensations (27-34%). The defects were located caudally of the abdominal cavity, displaying an even distribution in this region independent of time of HS. To determine if HS disturbed vertebral development during somitogenesis, two genes coding for markers of skeletal development were identified, namely, the secreted protein Shh (Sashh) and the transcription factor Twist (Satwist). These proteins are involved in the proliferation and specification of presumptive skeletal cells (sclerotome) in vertebrates. The spatial expression pattern of sashh and satwist in salmon indicated a functional conservation of these proteins. Furthermore, HS embryos displayed expressional disturbance in both sashh and satwist, indicating an effect of HS on sclerotomal cell patterning. However, the HS-protecting ability in embryos seems to be individually regulated because reduction in gene expression was not detected at all stages; in addition, HS did not induce somitic disturbance and vertebral deformity in all embryos.

Biomass shock pretreatment

DOEpatents

Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

2014-07-01

Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

Tissue-specific Requirements of β-Catenin in External Genitalia Development

PubMed Central

Lin, Congxing; Yin, Yan; Long, Fanxin; Ma, Liang

2008-01-01

SUMMARY External genitalia are body appendages specialized for internal fertilization. Its development can be divided into two phases, an early androgen-independent phase and a late androgen-dependant sexual differentiation phase. In the early phase, the embryonic anlage of external genitalia, the genital tubercle (GT), are morphologically identical in both sexes. Although congenital external genitalia malformations represent the second most common birth defect in humans, the genetic pathways governing early external genitalia development and urethra formation are poorly understood. Proper development of the GT requires coordinated outgrowth of the mesodermally-derived mesenchyme and extension of the endodermal urethra within an ectodermal epithelial capsule. Here we demonstrate that β-Catenin plays indispensable and distinct roles in each of the aforementioned three tissue layers in early androgen-independent GT development. WNT-β-Catenin signaling is required in the endodermal urethra to activate and maintain Fgf8 expression and direct GT outgrowth, as well as to maintain homeostasis of the urethra. Moreover, β-Catenin is required in the mesenchyme to promote cell proliferation. In contrast, β-Catenin is required in the ectoderm to maintain tissue integrity possibly through cell-cell adhesion during GT outgrowth. The fact that both endodermal and ectodermal β-Catenin knockout animals develop severe hypospadias in both sexes raises the possibility that deregulation of any of these functions can contribute to the etiology of congenital external genital defects in humans. PMID:18635608

The AGN-driven shock in NGC 4472

NASA Astrophysics Data System (ADS)

Gendron-Marsolais, Marie-Lou; Kraft, Ralph P.; Bogdan, Akos; Forman, William R.; Hlavacek-Larrondo, Julie; Jones, Christine; Nulsen, Paul; Randall, Scott W.; Roediger, Elke

2016-04-01

Chandra observations of most cool core clusters of galaxies have revealed large cavities where the inflation of the jet-driven radio bubbles displace the cluster gas. In a few cases, outburst shocks, likely driven by cavity inflation, are detected in the ambient gas. AGN-driven shocks may be key to balancing the radiative losses as shocks will increase the entropy of, and thereby heat, the diffuse gas. We will present initial results on deep Chandra observations of the nearby (D=17 Mpc) early-type massive elliptical galaxy NGC 4472, the most optically luminous galaxy in the local Universe, lying on the outskirts of the Virgo cluster. The X-ray observations show clear cavities in the X-ray emission at the position of the radio lobes, and rings of enhanced X-ray emission just beyond the lobes. We will present results from our analysis to determine whether the lobes are inflating supersonically or are rising buoyantly. We will compare the energy and power of this AGN outburst with previous powerful radio outbursts in clusters and groups to determine whether this outburst lies on the same scaling relations or whether it represents a new category of outburst.

Modeling Propagation of Shock Waves in Metals

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

Howard, W M; Molitoris, J D

2005-08-19

We present modeling results for the propagation of strong shock waves in metals. In particular, we use an arbitrary Lagrange Eulerian (ALE3D) code to model the propagation of strong pressure waves (P {approx} 300 to 400 kbars) generated with high explosives in contact with aluminum cylinders. The aluminum cylinders are assumed to be both flat-topped and have large-amplitude curved surfaces. We use 3D Lagrange mechanics. For the aluminum we use a rate-independent Steinberg-Guinan model, where the yield strength and shear modulus depend on pressure, density and temperature. The calculation of the melt temperature is based on the Lindermann law. Atmore » melt the yield strength and shear modulus is set to zero. The pressure is represented as a seven-term polynomial as a function of density. For the HMX-based high explosive, we use a JWL, with a program burn model that give the correct detonation velocity and C-J pressure (P {approx} 390 kbars). For the case of the large-amplitude curved surface, we discuss the evolving shock structure in terms of the early shock propagation experiments by Sakharov.« less

Modeling Propagation of Shock Waves in Metals

NASA Astrophysics Data System (ADS)

Howard, W. M.; Molitoris, J. D.

2006-07-01

We present modeling results for the propagation of strong shock waves in metals. In particular, we use an arbitrary Lagrange Eulerian (ALE3D) code to model the propagation of strong pressure waves (P ˜ 300 to 400 kbars) generated with high explosives in contact with aluminum cylinders. The aluminum cylinders are assumed to be both flat-topped and have large-amplitude curved surfaces. We use 3D Lagrange mechanics. For the aluminum we use a rate-independent Steinberg-Guinan model, where the yield strength and shear modulus depend on pressure, density and temperature. The calculation of the melt temperature is based on the Lindermann law. At melt the yield strength and shear modulus is set to zero. The pressure is represented as a seven-term polynomial as a function of density. For the HMX-based high explosive, we use a JWL, with a program burn model that give the correct detonation velocity and C-J pressure (P ˜ 390 kbars). For the case of the large-amplitude curved surface, we discuss the evolving shock structure in terms of the early shock propagation experiments by Sakharov.

Use of recombinant human activated protein C in nonmenstrual staphylococcal toxic shock syndrome

PubMed Central

Nasa, Prashant; Sehrawat, Deepak; kansal, Sudha; Chawla, Rajesh

2010-01-01

Toxic shock syndrome (TSS) is a serious, potentially life-threatening condition resulting from an overwhelming immunological response to an exotoxin released by Staphylococcus aureus and group A streptococci. High index of suspicion, early diagnosis and aggressive therapeutic measures must be instituted in view of high mortality of the TSS. In recent years, new agents have been tested to reduce morbidity and mortality in patients with severe sepsis, in addition to standard supportive measures. Among them, recombinant human activated protein C (rhAPC) has been reported to significantly reduce mortality and morbidity in patients with severe sepsis and two or more acute organ failures. We describe our experience with this drug in the early reversal of septic shock from TSS. PMID:21253349

Resuscitation and Transfusion Principles for Traumatic Hemorrhagic Shock

DTIC Science & Technology

2009-11-01

hyperfibrinolysis. We also describe the concept of damage control resuscitation (DCR), an early and aggressive prevention and treatment of hemorrhagic shock... prevention and treatment of acidosis, hypothermia, and hypocalcemia, avoidance of hemodilution, and hemostatic resuscitation with transfusion of red...are potentially preventable and 66–80% of these deaths occur from hemorrhage.3,4 Rural civilian data indicate that approximately 10% of traumatic

Sensitivity and specificity of two different automated external defibrillators.

PubMed

Israelsson, Johan; Wangenheim, Burkard von; Årestedt, Kristofer; Semark, Birgitta; Schildmeijer, Kristina; Carlsson, Jörg

2017-11-01

The aim was to investigate the clinical performance of two different types of automated external defibrillators (AEDs). Three investigators reviewed 2938 rhythm analyses performed by AEDs in 240 consecutive patients (median age 72, q1-q3=62-83) who had suffered cardiac arrest between January 2011 and March 2015. Two different AEDs were used (AED A n=105, AED B n=135) in-hospital (n=91) and out-of-hospital (n=149). Among 194 shockable rhythms, 17 (8.8%) were not recognized by AED A, while AED B recognized 100% (n=135) of shockable episodes (sensitivity 91.2 vs 100%, p<0.01). In AED A, 8 (47.1%) of these episodes were judged to be algorithm errors while 9 (52.9%) were caused by external artifacts. Among 1039 non-shockable rhythms, AED A recommended shock in 11 (1.0%), while AED B recommended shock in 63 (4.1%) of 1523 episodes (specificity 98.9 vs 95.9, p<0.001). In AED A, 2 (18.2%) of these episodes were judged to be algorithm errors (AED B, n=40, 63.5%), while 9 (81.8%) were caused by external artifacts (AED B, n=23, 36.5%). There were significant differences in sensitivity and specificity between the two different AEDs. A higher sensitivity of AED B was associated with a lower specificity while a higher specificity of AED A was associated with a lower sensitivity. AED manufacturers should work to improve the algorithms. In addition, AED use should always be reviewed with a routine for giving feedback, and medical personnel should be aware of the specific strengths and shortcomings of the device they are using. Copyright © 2017 Elsevier B.V. All rights reserved.

Cosmic-ray shock acceleration in oblique MHD shocks

NASA Technical Reports Server (NTRS)

Webb, G. M.; Drury, L. OC.; Volk, H. J.

1986-01-01

A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.

Calculating shock arrival in expansion tubes and shock tunnels using Bayesian changepoint analysis

NASA Astrophysics Data System (ADS)

James, Christopher M.; Bourke, Emily J.; Gildfind, David E.

2018-06-01

To understand the flow conditions generated in expansion tubes and shock tunnels, shock speeds are generally calculated based on shock arrival times at high-frequency wall-mounted pressure transducers. These calculations require that the shock arrival times are obtained accurately. This can be non-trivial for expansion tubes especially because pressure rises may be small and shock speeds high. Inaccurate shock arrival times can be a significant source of uncertainty. To help address this problem, this paper investigates two separate but complimentary techniques. Principally, it proposes using a Bayesian changepoint detection method to automatically calculate shock arrival, potentially reducing error and simplifying the shock arrival finding process. To compliment this, a technique for filtering the raw data without losing the shock arrival time is also presented and investigated. To test the validity of the proposed techniques, tests are performed using both a theoretical step change with different levels of noise and real experimental data. It was found that with conditions added to ensure that a real shock arrival time was found, the Bayesian changepoint analysis method was able to automatically find the shock arrival time, even for noisy signals.

Dynamic loads on human and animal surrogates at different test locations in compressed-gas-driven shock tubes

NASA Astrophysics Data System (ADS)

Alay, E.; Skotak, M.; Misistia, A.; Chandra, N.

2018-01-01

Dynamic loads on specimens in live-fire conditions as well as at different locations within and outside compressed-gas-driven shock tubes are determined by both static and total blast overpressure-time pressure pulses. The biomechanical loading on the specimen is determined by surface pressures that combine the effects of static, dynamic, and reflected pressures and specimen geometry. Surface pressure is both space and time dependent; it varies as a function of size, shape, and external contour of the specimens. In this work, we used two sets of specimens: (1) anthropometric dummy head and (2) a surrogate rodent headform instrumented with pressure sensors and subjected them to blast waves in the interior and at the exit of the shock tube. We demonstrate in this work that while inside the shock tube the biomechanical loading as determined by various pressure measures closely aligns with live-fire data and shock wave theory, significant deviations are found when tests are performed outside.

Thermographic Phosphor Measurements of Shock-Shock Interactions on a Swept Cylinder

NASA Technical Reports Server (NTRS)

Jones, Michelle L.; Berry, Scott A.

2013-01-01

The effects of fin leading-edge radius and sweep angle on peak heating rates due to shock-shock interactions were investigated in the NASA Langley Research Center 20-inch Mach 6 Air Tunnel. The fin model leading edges, which represent cylindrical leading edges or struts on hypersonic vehicles, were varied from 0.25 inches to 0.75 inches in radius. A 9deg wedge generated a planar oblique shock at 16.7deg to the flow that intersected the fin bow shock, producing a shock-shock interaction that impinged on the fin leading edge. The fin angle of attack was varied from 0deg (normal to the free-stream) to 15deg and 25deg swept forward. Global temperature data was obtained from the surface of the fused silica fins using phosphor thermography. Metal oil flow models with the same geometries as the fused silica models were used to visualize the streamline patterns for each angle of attack. High-speed zoom-schlieren videos were recorded to show the features and temporal unsteadiness of the shock-shock interactions. The temperature data were analyzed using one-dimensional semi-infinite as well as one- and two-dimensional finite-volume methods to determine the proper heat transfer analysis approach to minimize errors from lateral heat conduction due to the presence of strong surface temperature gradients induced by the shock interactions. The general trends in the leading-edge heat transfer behavior were similar for the three shock-shock interactions, respectively, between the test articles with varying leading-edge radius. The dimensional peak heat transfer coefficient augmentation increased with decreasing leading-edge radius. The dimensional peak heat transfer output from the two-dimensional code was about 20% higher than the value from a standard, semi-infinite onedimensional method.

Revisiting the “Golden Hour”: An Evaluation of Out-of-Hospital Time in Shock and Traumatic Brain Injury

PubMed Central

Newgard, Craig D.; Meier, Eric N.; Bulger, Eileen M.; Buick, Jason; Sheehan, Kellie; Lin, Steve; Minei, Joseph P.; Barnes-Mackey, Roxy A.; Brasel, Karen

2015-01-01

Study Objective We evaluated shock and traumatic brain injury (TBI) patients previously enrolled in an out-of-hospital clinical trial to test the association between out-of-hospital time and outcome. Methods This was a secondary analysis of shock and TBI patients ≥ 15 years enrolled in a Resuscitation Outcomes Consortium out-of-hospital clinical trial by 81 EMS agencies transporting to 46 Level I and II trauma centers in 11 sites (May 2006 through May 2009). Inclusion criteria were: SBP ≤ 70 mmHg or SBP 71 - 90 mmHg with heart rate ≥ 108 beats per minute (shock cohort) and Glasgow Coma Scale score ≤ 8 (TBI cohort); patients meeting both criteria were placed in the shock cohort. Primary outcomes were 28-day mortality (shock cohort) and 6-month Glasgow Outcome Scale - Extended (GOSE) ≤ 4 (TBI cohort). Results There were 778 patients in the shock cohort (26% 28-day mortality) and 1,239 patients in the TBI cohort (53% 6-month GOSE ≤ 4). Out-of-hospital time > 60 minutes was not associated with worse outcomes after accounting for important confounders in the shock cohort (adjusted odds ratio [aOR] 1.42, 95% CI 0.77-2.62) or TBI cohort (aOR 0.80, 95% CI 0.52-1.21). However, shock patients requiring early critical hospital resources and arriving > 60 minutes had higher 28-day mortality (aOR 2.37, 95% CI 1.05-5.37); this finding was not observed among a similar TBI subgroup. Conclusions Among out-of-hospital trauma patients meeting physiologic criteria for shock and TBI, there was no association between time and outcome. However, the subgroup of shock patients requiring early critical resources arriving after 60 minutes had higher mortality. PMID:25596960

Similarities and Differences between the Termination Foreshock/ Bow Shock and Planetary Bow Shocks

NASA Astrophysics Data System (ADS)

Krimigis, S. M.; Decker, R. B.; Roelof, E. C.; Hill, M. E.

2006-05-01

It is now evident that Voyager 1 (V1) entered the termination foreshock (TFS) at ~~85 AU in mid-2002, exited this region in early 2003 and re-entered in the late 2003-early 2004 time frame, before finally crossing the termination shock (TS) at ~~94 AU on December 16, 2004. The TFS region is characterized by large intensities of tangentially outward-moving beams of energetic ions E > 40 keV, and generally isotropic electron intensity increases E > 350 keV (Krimigis et al, 2003; Decker et al, 2005). Elevated magnetic field intensities were observed throughout these periods (Burlaga et al, 2003, 2005) and comparison with particle pressures showed this region to be a high-beta plasma (Krimigis et al, 2004, 2005). Proximity of the TS was also evident from occasional electron plasma oscillations seen as early as 91 AU (Gurnett and Kurth, 2005). In this paper we examine the extent to which the TFS and TS exhibit properties seen in planetary bow shocks using data from Voyager?s flyby of the outer planets and Cassini data in the vicinity of Saturn. Magnetic field distributions in these high-beta regions appear to be Gaussian. A possible source for the TSF particles is the supertherma1 population residing in the heliosheath, similar to upstream ions observed leaking from planetary magnetospheres. Krimigis, S.M. et al, Nature, 426, pg 45-48, 2003. Decker, R. B. et al, Science, 309, 2020- 2024, 2005. Burlaga et al, Geophys. Res. Lett., 30, NO. 20, 2072, doi:10.1029/2003GL018291, 2003. Burlaga, L. F, et al, Science, 309, 2027-2029, 2005 Krimigis S. M., et al, V. Florinski, N. V. Pogorelov, and G. P. Zank (eds) CP719, American Institute of Physics, 0-7354-0199-3/04, 133-138, 2004. Krimigis, S. M., et al, Proceedings of the Solar Wind 11 / SOHO 16 Conference,12-17 June 2005, Whistler, Canada, , B. Fleck & T.H. Zurbuchen (eds), (ESA SP-592, September 2005) Gurnett, D. A., and W. S. Kurth, Science, 309, 2025- 2027, 2005

[Central venous-arterial carbon dioxide tension to arterial-central venous oxygen content ratio combined with lactate clearance rate as early resuscitation goals of septic shock].

PubMed

Gao, X H; Li, P J; Cao, W

2018-02-13

Objective: To investigate the prognostic significance of central venous-arterial carbon dioxide tension to arterial-venous oxygen content ratio (Pcv-aCO(2)/Ca-cvO(2)) combined with lactate clearance rate (LCR) as early resuscitation goals of septic shock. Methods: One hundred and forty-five septic shock patients admitted to Second Department of Critical Care Medicine of Lanzhou University Second Hospital from March 2013 to May 2017 were enrolled in this study.All septic shock patients received an initial resuscitation therapy according to early goal-directed therapy.The arterial and central venous blood gases were measured simultaneously at baseline (T0) and 6 hours after resuscitation (T6). Pcv-aCO(2)/Ca-cvO(2) and LCR were calculated.Patients were classified into four groups according to Pcv-aCO(2)/Ca-cvO(2) and LCR at T6: group A, Pcv-aCO(2)/Ca-cvO(2)>1.8 and LCR<30%; group B, Pcv-aCO(2)/Ca-cvO(2)>1.8 and LCR≥30%; group C, Pcv-aCO(2)/Ca-cvO(2)≤1.8 and LCR<30%; group D, Pcv-aCO(2)/Ca-cvO(2)≤1.8 and LCR≥30%.General demographics, hemodynamic parameters, oxygen metabolism parameters, acute physiology and chronic health evaluation (APACHE Ⅱ) scores, sequential organ failure assessment (SOFA) scores, length of intensive care unit (ICU) stay, and 28-day mortality rate were compared among the 4 groups.A Kaplan-Meier curve showed the survival probabilities at day 28 using a log-rank test for multiple comparisons.Parameters were introduced into a Cox's proportional hazards regression model to analyze the prediction of 28-day mortality.Receiver operating characteristics (ROC) curves were constructed to evaluate the ability of Pcv-aCO(2)/Ca-cvO(2), LCR, Pcv-aCO(2)/Ca-cvO(2) combined with LCR at T6 to predict 28-day mortality. Results: Compared with patients in group A, patients from group D had the lower APACHE Ⅱ and SOFA score at day 3 ( t =-2.909, -3.630, both P <0.05), shorter ICU stay ( t =-2.575, P =0.011), and lower mortality rate at day 28 (χ(2)=3.124, P

Transcription of exogenous and endogenous deoxyribonucleic acid templates in cold-shocked Bacillus subtilis.

PubMed Central

Kuhl, S J; Brown, L R

1980-01-01

Ribonucleic acid (RNA) synthesis was examined in cold-shocked Bacillus subtilis cells. The cells were grown to mid-log stage, harvested, and cold shocked. RNA synthesis was monitored by the incorporation of [3H]uridine triphosphate or [alpha 32P]adenosine triphosphate into trichloroacetic acid-precipitable material in the presence of all four nucleoside triphosphates. The inhibition of RNA synthesis in cold-shocked cells by lipiarmycin, ethidium bromide, rifampin. or streptolydigin was analyzed using mutant or wild-type cells. Also examined were the effects of temperature, salt concentration, and the addition of polyamines or highly phosphorylated nucleotides. In ultraviolet-irradiated and cold-shocked cells, RNA wynthesis decreased to low levels. The addition of exogenous phi 29 or TSP-1 template to these cells caused a 13- to 20-fold increase in RNA synthesis, as monitored by trichloroacetic acid-precipitable counts. RNA synthesized in the presence of phi 29 deoxyribonucleic acid (DNA) hybridizes mainly to EcoRI fragments A and C of phi 29 DBA, These two fragments direct transcription by purified RNA polymerase in vitro and hybridize to early phi 29 DNA produced in vivo. Our results with TSP-1 DNA in this system indicated that the RNA produced hybridizes to the same fragments as early RNA produced in vivo. Plasmic pUB110 DNA was not transcribed in this system. Images PMID:6157674

Fast molecular shocks. II - Emission from fast dissociative shocks

NASA Technical Reports Server (NTRS)

Neufeld, David A.; Dalgarno, A.

1989-01-01

The line radiations emitted in the cooling gas behind a fast dissociative shock are studied. The intensities emitted in high rotational transitions of the neutral molecules CO, SiO, HCN, CN, NO, and SO are estimated, as well as in rovibrational transitions of the molecular ions HeH(+) and OH(+) in radio recombination lines of atomic hydrogen and in fine-structure transitions of C, C(+), O, and Si(+). The predictions are compared with the observed intensities of line emission from the Orion-KL region. For Orion-KL the observations do not exclude, but probably do not require, the presence of a fast dissociative shock. Emission from SiO in high-J rotational states and from vibrationally excited OH(+), HeH(+), HeH(+), and SO(+) may be detectable from dissociative shocks under suitable conditions of preshock density and shock velocity; such emission may prove to be a useful diagnostic probe of fast shock activity.

[Acute heart failure: acute cardiogenic pulmonary edema and cardiogenic shock].

PubMed

Sánchez Marteles, Marta; Urrutia, Agustín

2014-03-01

Acute cardiogenic pulmonary edema and cardiogenic shock are two of the main forms of presentation of acute heart failure. Both entities are serious, with high mortality, and require early diagnosis and prompt and aggressive management. Acute pulmonary edema is due to the passage of fluid through the alveolarcapillary membrane and is usually the result of an acute cardiac episode. Correct evaluation and clinical identification of the process is essential in the management of acute pulmonary edema. The initial aim of treatment is to ensure hemodynamic stability and to correct hypoxemia. Other measures that can be used are vasodilators such as nitroglycerin, loop diuretics and, in specific instances, opioids. Cardiogenic shock is characterized by sustained hypoperfusion, pulmonary wedge pressure > 18 mmHg and a cardiac index < 2.2l/min/m(2). The process typically presents with hypotension (systolic blood pressure < 90 mmHg or a decrease in mean arterial pressure > 30 mmHg) and absent or reduced diuresis (< 0.5 ml/kg/h). The most common cause is left ventricular failure due to acute myocardial infarction. Treatment consists of general measures to reverse acidosis and hypoxemia, as well as the use of vasopressors and inotropic drugs. Early coronary revascularization has been demonstrated to improve survival in shock associated with ischaemic heart disease. Copyright © 2014 Elsevier España, S.L. All rights reserved.

Simulations of the Richtmyer-Meshkov Instability in a two-shock vertical shock tube

NASA Astrophysics Data System (ADS)

Ferguson, Kevin; Olson, Britton; Jacobs, Jeffrey

2017-11-01

Simulations of the Richtmyer-Meshkov Instability (RMI) in a new two-shock vertical shock tube configuration are presented. The simulations are performed using the ARES code at Lawrence-Livermore National Laboratory (LLNL). Two M=1.2 shock waves travel in opposing directions and impact an initially stationary interface formed by sulfur hexaflouride (SF6) and air. The delay between the two shocks is controlled to achieve a prescribed temporal separation in shock wave arrival time. Initial interface perturbations and diffusion profiles are generated in keeping with previously gathered experimental data. The effect of varying the inter-shock delay and initial perturbation structure on instability growth and mixing parameters is examined. Information on the design, construction, and testing of a new two-shock vertical shock tube are also presented.

Design, calibration and testing of a force balance for a hypersonic shock tunnel

NASA Astrophysics Data System (ADS)

Vadassery, Pravin

The forces acting on a flight vehicle are critical for determining its performance. Of particular interest is the hypersonic regime. Force measurements are much more complex in hypersonic flows, where those speeds are simulated in shock tunnels. A force balance for such facilities contains sensitive gages that measure stress waves and ultimately determine the different components of force acting on the model. An external force balance was designed and fabricated for the UTA Hypersonic shock tunnel to measure drag at Mach 10. Static and dynamic calibrations were performed to find the transfer function of the system. Forces were recovered using a deconvolution procedure. To validate the force balance, experiments were conducted on a blunt cone. The measured forces were compared to Newtonian theory.

Calculation of oblique-shock-wave laminar-boundary-layer interaction on a flat plate

NASA Technical Reports Server (NTRS)

Goldberg, U.; Reshotko, E.

1980-01-01

A finite difference solution to the problem of the interaction between an impinging oblique shock wave and the laminar boundary layer on a flat plate is presented. The boundary layer equations coupled with the Prandtl-Meyer relation for the external flow are used to calculate the flow field. A method for the calculation of the separated flow region is presented and discussed. Comparisons between this theory and the experimental results of other investigators show fairly good agreement. Results are presented for the case of a cooled wall with an oncoming flow at Mach number 2.0 without and with suction. The results show that a small amount of suction greatly reduces the extent of the separated region in the vicinity of the shock impingement location.

Structure in Radiative Shocks

NASA Astrophysics Data System (ADS)

Drake, R. Paul; Visco, A.; Doss, F.; Reighard, A.; Froula, D.; Glenzer, S.; Knauer, J.

2008-05-01

Radiative shocks are shock waves fast enough that radiation from the shock-heated matter alters the structure of the shock. They are of fundamental interest to high-energy-density physics and also have applications throughout astrophysics. This poster will review the dimensionless parameters that determine structure in these shocks and will discuss recent experiments to measure such structure for strongly radiative shocks that are optically thin upstream and optically thick downstream. The shock transition itself heats mainly the ions. Immediately downstream of the shock, the ions heat the electrons and the electrons radiate, producing an optically thin cooling layer, followed by the downstream layer of warm, shocked material. The axial structure of these systems is of interest, because the transition from precursor through the cooling layer to the final state is complex and difficult to calculate. Their lateral structure is also of interest, as they seem likely to be subject to some variation on the Vishniac instability of thin layers. In our experiments to produce such shocks, laser ablation launches a Be plasma into a tube of Xe or Ar gas, at a velocity above 100 km/s. This drives a shock down the tube. Radiography provides fundamental information about the structure and evolution of the shocked material in Xe. Thomson scattering and pyrometry have provided data in Ar. We will summarize the available evidence regarding the properties of these shocks, and will discuss their connections to astrophysical cases. This research was sponsored by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

Early changes in coagulation profiles and lactate levels in patients with septic shock undergoing extracorporeal membrane oxygenation

PubMed Central

Kim, Hyoung Soo; Cheon, Dae Young; Ha, Sang Ook; Han, Sang Jin; Kim, Hyun-Sook; Lee, Sun Hee; Kim, Sung Gyun

2018-01-01

Background To investigate the impact of coagulation profiles and lactate levels in patients with septic shock undergoing extracorporeal membrane oxygenation (ECMO). Methods A retrospective analysis of coagulation profiles, including disseminated intravascular coagulation (DIC) score, before and during 48 h of ECMO support [on day 0 (pre-ECMO), day 1, and day 2], was conducted in patients with septic shock undergoing ECMO. Results A total of 37 patients were included, and 15 (40.5%) patients survived. The initial DIC scores did not change in either the pre-ECMO overt-DIC (n=15) or non-overt-DIC (n=22) group after ECMO commencement. However, the DIC scores were significantly higher, at all three time-points, in non-survivors than in survivors. Additionally, the lactate levels improved considerably in the pre-ECMO non-overt-DIC group and in survivors during ECMO support, but not in the pre-ECMO overt DIC group or non-survivors. On a multivariate analysis, the pre-ECMO DIC score was significantly associated with hospital death [odds ratio (OR), 3.935; 95% confidence interval (CI), 1.170–13.230]. Receiver operating characteristic (ROC) curves revealed that the combination of pre-ECMO DIC score plus lactate level was the best predictor of hospital death (area under the curve, 0.879; 0.771–0.987); patients with combined scores >9.35 (the optimal cut-off) exhibited a three-fold higher mortality rate than did those with lower scores (81.8% vs. 26.7%, P=0.001). Conclusions During the early period of ECMO support, the coagulation profiles and lactate levels exhibited different trajectories in survivors and non-survivors. Furthermore, the pre-ECMO DIC score plus lactate level was the best predictor of hospital death. PMID:29707291

Thermospheric Nitric Oxide Response to Shock-led Storms

PubMed Central

Knipp, D. J.; Pette, D. V.; Kilcommons, L. M.; Isaacs, T. L.; Cruz, A. A.; Mlynczak, M. G.; Hunt, L. A.; Lin, C. Y.

2017-01-01

We present a multi-year superposed epoch study of the Sounding of the Atmosphere using Broadband Emission Radiometry nitric oxide (NO) emission data. NO is a trace constituent in the thermosphere that acts as cooling agent via infrared (IR) emissions. The NO cooling competes with storm time thermospheric heating resulting in a thermostat effect. Our study of nearly 200 events reveals that shock-led interplanetary coronal mass ejections (ICMEs) are prone to early and excessive thermospheric NO production and IR emissions. Excess NO emissions can arrest thermospheric expansion by cooling the thermosphere during intense storms. The strongest events curtail the interval of neutral density increase and produce a phenomenon known as thermospheric ‘overcooling’. We use Defense Meteorological Satellite Program particle precipitation data to show that interplanetary shocks and their ICME drivers can more than double the fluxes of precipitating particles that are known to trigger the production of thermospheric NO. Coincident increases in Joule heating likely amplify the effect. In turn, NO emissions more than double. We discuss the roles and features of shock/sheath structures that allow the thermosphere to temper the effects of extreme storm time energy input and explore the implication these structures may have on mesospheric NO. Shock-driven thermospheric NO IR cooling likely plays an important role in satellite drag forecasting challenges during extreme events. PMID:28824340

Thermospheric Nitric Oxide Response to Shock-led Storms.

PubMed

Knipp, D J; Pette, D V; Kilcommons, L M; Isaacs, T L; Cruz, A A; Mlynczak, M G; Hunt, L A; Lin, C Y

2017-02-01

We present a multi-year superposed epoch study of the Sounding of the Atmosphere using Broadband Emission Radiometry nitric oxide (NO) emission data. NO is a trace constituent in the thermosphere that acts as cooling agent via infrared (IR) emissions. The NO cooling competes with storm time thermospheric heating resulting in a thermostat effect. Our study of nearly 200 events reveals that shock-led interplanetary coronal mass ejections (ICMEs) are prone to early and excessive thermospheric NO production and IR emissions. Excess NO emissions can arrest thermospheric expansion by cooling the thermosphere during intense storms. The strongest events curtail the interval of neutral density increase and produce a phenomenon known as thermospheric 'overcooling'. We use Defense Meteorological Satellite Program particle precipitation data to show that interplanetary shocks and their ICME drivers can more than double the fluxes of precipitating particles that are known to trigger the production of thermospheric NO. Coincident increases in Joule heating likely amplify the effect. In turn, NO emissions more than double. We discuss the roles and features of shock/sheath structures that allow the thermosphere to temper the effects of extreme storm time energy input and explore the implication these structures may have on mesospheric NO. Shock-driven thermospheric NO IR cooling likely plays an important role in satellite drag forecasting challenges during extreme events.

Bugbuster: Survivability of Living Bacteria Upon Shock Compression

NASA Astrophysics Data System (ADS)

Willis, M. J.; Ahrens, T. J.; Bertani, L. E.; Nash, C. Z.

2003-12-01

Survivability of bacteria during impact events has implications both for the transport of life between planets and development of organisms on Hadean Earth and other planets during the period of heavy bombardment which ended 3.5 Gyr before the present [1]. We envision that life existed within internal rock surfaces immersed in the early ocean. We performed shock recovery experiments on live E. coli bacteria to determine survival rate vs. shock pressure. Samples of 2x107 cells were suspended in ˜10-5 l of a buffer solution (TE: a 10:1 solution of Tris and EDTA), sealed into stainless steel chambers that are impacted by 1.5 mm thick flyer plates at 670-760 m s-1 using a 20 mm gun. Recovered liquid was mixed with a nutrient broth (LB: growth medium containing tryptone, yeast extract and NaCl) and spread on a Petrie dish containing agar (a polysaccharide growth medium extracted from marine algae Rhodophyceae). Recovered samples were cultured for ˜16 hours at 37° C. In addition, sample bacteria studied under an optical microscope with DAPI fluorescent stain to verify presence of bacteria in shock recovered samples. Initial and reverberated shock pressures in H2O varied from 0.2 to 2.0 and 2.4 to 14.9 GPa respectively. We modeled the bacteria cell walls with stilbene, ρ 0=1.16 g cm-3, US=2.866+1.588uP and the cell interiors as water. Upon initial loading the net strain imposed on E. coli that just caused non-survival for 10-6 s duration stress was 2.8. If this strain is characteristic of that tolerable by E. coli, we predict that shock stresses of 25 MPa, 25 kPa and 25 Pa are sustainable upon shock loading by 0.1 ms, 0.1 s and 100 s shock duration pulses. Such shock durations are induced by 2.5 m, 2.5 km and 2,500 km diameter silicate impactors. References: [1] Maher K.A. & Stevenson D.J., Nature, 331, pp.612-614, 1988

Investigation of shock focusing in a cavity with incident shock diffracted by an obstacle

NASA Astrophysics Data System (ADS)

Zhang, Q.; Chen, X.; He, L.-M.; Rong, K.; Deiterding, R.

2017-03-01

Experiments and numerical simulations were carried out in order to investigate the focusing of a shock wave in a test section after the incident shock has been diffracted by an obstacle. A conventional shock tube was used to generate the planar shock. Incident shock Mach numbers of 1.4 and 2.1 were tested. A high-speed camera was employed to obtain schlieren photos of the flow field in the experiments. In the numerical simulations, a weighted essentially non-oscillatory (WENO) scheme of third-order accuracy supplemented with structured dynamic mesh adaptation was adopted to simulate the shock wave interaction. Good agreement between experiments and numerical results is observed. The configurations exhibit shock reflection phenomena, shock-vortex interaction and—in particular—shock focusing. The pressure history in the cavity apex was recorded and compared with the numerical results. A quantitative analysis of the numerically observed shock reflection configurations is also performed by employing a pseudo-steady shock transition boundary calculation technique. Regular reflection, single Mach reflection and transitional Mach reflection phenomena are observed and are found to correlate well with analytic predictions from shock reflection theory.

Laser-shocked energetic materials with metal additives: evaluation of detonation performance

NASA Astrophysics Data System (ADS)

Gottfried, Jennifer; Bukowski, Eric

A focused, nanosecond-pulsed laser with sufficient energy to exceed the breakdown threshold of a material generates a laser-induced plasma with high peak temperatures, pressures, and shock velocities. Depending on the laser parameters and material properties, nanograms to micrograms of material is ablated, atomized, ionized and excited in the laser-induced plasma. The subsequent shock wave expansion into the air above the sample has been monitored using high-speed schlieren imaging in a recently developed technique, laser-induced air shock from energetic materials (LASEM). The estimated detonation velocities using LASEM agree well with published experimental values. A comparison of the measured shock velocities for various energetic materials including RDX, DNTF, and LLM-172 doped with Al or B to the detonation velocities predicted by CHEETAH for inert or active metal participation demonstrates that LASEM has potential for predicting the early time participation of metal additives in detonation events. The LASEM results show that reducing the amount of hydrogen present in B formulations increases the resulting detonation velocities

Use of infrared thermography in children with shock: A case series

PubMed Central

Ortiz-Dosal, Alejandra; Rivera-Vega, Rosalina; Simón, Jorge; González, Francisco J

2014-01-01

Shock is a complex clinical syndrome caused by an acute failure of circulatory function resulting in inadequate tissue and organ perfusion. Digital infrared thermal imaging is a non-invasive technique that can detect changes in blood perfusion by detecting small changes in the temperature of the skin. In this preliminary study, eight pediatric patients (five boys, three girls), ages ranging from 6 to 14 years (average: 9.8 years), were admitted to the Intensive Care Unit at “Dr. Ignacio Morones Prieto” Central Hospital; here, the patients were examined using digital infrared thermal imaging. Patients in shock showed a significant decrease in distal temperature (at least 7°), compared to critically ill patients without shock. The latter group presented a skin temperature pattern very similar to the one previously reported for healthy children. The results show that infrared thermography can be used as a non-invasive method for monitoring the temperature in pediatric patients in intensive care units in order to detect shock in its early stages. PMID:27489669

Use of infrared thermography in children with shock: A case series.

PubMed

Ortiz-Dosal, Alejandra; Kolosovas-Machuca, Eleazar S; Rivera-Vega, Rosalina; Simón, Jorge; González, Francisco J

2014-01-01

Shock is a complex clinical syndrome caused by an acute failure of circulatory function resulting in inadequate tissue and organ perfusion. Digital infrared thermal imaging is a non-invasive technique that can detect changes in blood perfusion by detecting small changes in the temperature of the skin. In this preliminary study, eight pediatric patients (five boys, three girls), ages ranging from 6 to 14 years (average: 9.8 years), were admitted to the Intensive Care Unit at "Dr. Ignacio Morones Prieto" Central Hospital; here, the patients were examined using digital infrared thermal imaging. Patients in shock showed a significant decrease in distal temperature (at least 7°), compared to critically ill patients without shock. The latter group presented a skin temperature pattern very similar to the one previously reported for healthy children. The results show that infrared thermography can be used as a non-invasive method for monitoring the temperature in pediatric patients in intensive care units in order to detect shock in its early stages.

Trajectories of Religious Coping from Adolescence into Early Adulthood: Their Form and Relations to Externalizing Problems and Prosocial Behavior

PubMed Central

Eisenberg, Nancy; Castellani, Valeria; Panerai, Laura; Eggum, Natalie D.; Cohen, Adam B.; Pastorelli, Concetta; Caprara, Gian Vittorio

2011-01-01

Little is known about changes in religious coping and their relations to adolescents’ and young adults’ functioning. In 686 Italian youths, trajectories of religious coping were identified from age 16–17 years to age 22–23 years; cohorts of youths reported at three of the four assessments. Four trajectories of religious coping were identified: decreasing, low stable, high stable, and increasing. A decline in religious coping was associated with high levels of externalizing problems at age 16–17, whereas an increase in religious coping was associated with higher externalizing problems at ages 18–19 and 20–21 years, and with relatively high involvement with deviant peers. High stable religious copers were high in prosocial behavior at three ages; low stable religious copers were higher than people undergoing change in their religious coping from mid-adolescence into early adulthood. These results can expand our current thinking about religious coping and adolescent adjustment. PMID:21682728

Computational and Experimental Study of Supersonic Nozzle Flow and Shock Interactions

NASA Technical Reports Server (NTRS)

Carter, Melissa B.; Elmiligui, Alaa A.; Nayani, Sudheer N.; Castner, Ray; Bruce, Walter E., IV; Inskeep, Jacob

2015-01-01

This study focused on the capability of NASA Tetrahedral Unstructured Software System's CFD code USM3D capability to predict the interaction between a shock and supersonic plume flow. Previous studies, published in 2004, 2009 and 2013, investigated USM3D's supersonic plume flow results versus historical experimental data. This current study builds on that research by utilizing the best practices from the early papers for properly capturing the plume flow and then adding a wedge acting as a shock generator. This computational study is in conjunction with experimental tests conducted at the Glenn Research Center 1'x1' Supersonic Wind Tunnel. The comparison of the computational and experimental data shows good agreement for location and strength of the shocks although there are vertical shifts between the data sets that may be do to the measurement technique.

Shock loading predictions from application of indicial theory to shock-turbulence interactions

NASA Technical Reports Server (NTRS)

Keefe, Laurence R.; Nixon, David

1991-01-01

A sequence of steps that permits prediction of some of the characteristics of the pressure field beneath a fluctuating shock wave from knowledge of the oncoming turbulent boundary layer is presented. The theory first predicts the power spectrum and pdf of the position and velocity of the shock wave, which are then used to obtain the shock frequency distribution, and the pdf of the pressure field, as a function of position within the interaction region. To test the validity of the crucial assumption of linearity, the indicial response of a normal shock is calculated from numerical simulation. This indicial response, after being fit by a simple relaxation model, is used to predict the shock position and velocity spectra, along with the shock passage frequency distribution. The low frequency portion of the shock spectra, where most of the energy is concentrated, is satisfactorily predicted by this method.

Development of the embryonic heat shock response and the impact of repeated thermal stress in early stage lake whitefish (Coregonus clupeaformis) embryos.

PubMed

Whitehouse, Lindy M; McDougall, Chance S; Stefanovic, Daniel I; Boreham, Douglas R; Somers, Christopher M; Wilson, Joanna Y; Manzon, Richard G

2017-10-01

Lake whitefish (Coregonus clupeaformis) embryos were exposed to thermal stress (TS) at different developmental stages to determine when the heat shock response (HSR) can be initiated and if it is altered by exposure to repeated TS. First, embryos were subject to one of three different TS temperatures (6, 9, or 12°C above control) at 4 points in development (21, 38, 60 and 70 days post-fertilisation (dpf)) for 2h followed by a 2h recovery to understand the ontogeny of the HSR. A second experiment explored the effects of repeated TS on the HSR in embryos from 15 to 75 dpf. Embryos were subjected to one of two TS regimes; +6°C TS for 1h every 6 days or +9°C TS for 1h every 6 days. Following a 2h recovery, a subset of embryos was sampled. Our results show that embryos could initiate a HSR via upregulation of heat shock protein 70 (hsp70) mRNA at all developmental ages studied, but that this response varied with age and was only observed with a TS of +9 or +12°C. In comparison, when embryos received multiple TS treatments, hsp70 was not induced in response to the 1h TS and 2h recovery, and a downregulation was observed at 39 dpf. Downregulation of hsp47 and hsp90α mRNA was also observed in early age embryos. Collectively, these data suggest that embryos are capable of initiating a HSR at early age and throughout embryogenesis, but that repeated TS can alter the HSR, and may result in either reduced responsiveness or a downregulation of inducible hsps. Our findings warrant further investigation into both the short- and long-term effects of repeated TS on lake whitefish development. Copyright © 2017 Elsevier Ltd. All rights reserved.

Principles and application of shock-tubes and shock tunnels

NASA Technical Reports Server (NTRS)

Ried, R. C.; Clauss, H. G., Jr.

1963-01-01

The principles, theoretical flow equations, calculation techniques, limitations and practical performance characteristics of basic and high performance shock tubes and shock tunnels are presented. Selected operating curves are included.

Shock Isolation Elements Testing for High Input Loadings. Volume II. Foam Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*EXPANDED PLASTICS, (*SHOCK(MECHANICS), REDUCTION), TEST METHODS, SHOCK WAVES, STRAIN(MECHANICS), LOADS(FORCES), MATHEMATICAL MODELS, NUCLEAR EXPLOSIONS, HARDENING.

[Inappropriate analyses of automated external defibrillators used during out-of-hospital cardiac arrests].

PubMed

Ballesteros Peña, Sendoa

2013-04-01

To estimate the frequency of therapeutic errors and to evaluate the diagnostic accuracy in the recognition of shockable rhythms by automated external defibrillators. A retrospective descriptive study. Nine basic life support units from Biscay (Spain). Included 201 patients with cardiac arrest, since 2006 to 2011. The study was made of the suitability of treatment (shock or not) after each analysis and medical errors identified. The sensitivity, specificity and predictive values with 95% confidence intervals were then calculated. A total of 811 electrocardiographic rhythm analyses were obtained, of which 120 (14.1%), from 30 patients, corresponded to shockable rhythms. Sensitivity and specificity for appropriate automated external defibrillators management of a shockable rhythm were 85% (95% CI, 77.5% to 90.3%) and 100% (95% CI, 99.4% to 100%), respectively. Positive and negative predictive values were 100% (95% CI, 96.4% to 100%) and 97.5% (95% CI, 96% to 98.4%), respectively. There were 18 (2.2%; 95% CI, 1.3% to 3.5%) errors associated with defibrillator management, all relating to cases of shockable rhythms that were not shocked. One error was operator dependent, 6 were defibrillator dependent (caused by interaction of pacemakers), and 11 were unclassified. Automated external defibrillators have a very high specificity and moderately high sensitivity. There are few operator dependent errors. Implanted pacemakers interfere with defibrillator analyses. Copyright © 2012 Elsevier España, S.L. All rights reserved.

A new method to study he effective shear modulus of shocked material

NASA Astrophysics Data System (ADS)

Xiaojuan, Ma; Fusheng, Liu

2013-06-01

Shear modulus is a crucial material parameter for description of mechanical behavior. However, at strong shock compression, it is generally deduced from the longitudinal and bulk sound velocity evaluated by unloading wave profile measurement. Here, a new method called the disturbed amplitude damping method of shock wave is presented, that can directly measure the shear modulus of material. This method relies on the correlation between the shear modulus of shock compressed state and amplitude damping and oscillation of an initial sinusoidal disturbance on shock front in concerned substance. Two important steps are required to determine the shear modulus of material. The first is to measure the damping and oscillation feature of disturbance by the flyer impacted method. The second is to find the quantitative relationship between the disturbed amplitude damping and shear modulus by the finite difference method which is applied to obtain the numerical solutions for disturbance amplitude damping behavior of sinusoidal shock front in flyer impacted flow field. When aluminum shocked to 80 GPa is taken as an example, the shape of perturbed shock front and its disturbed amplitude development with propagation distance, are approximately mapped out. The figure shows an oscillatory damping characteristic. At the early stage the perturbation amplitude on the shock front experiences a decaying process until to zero point, then it rises to a maximum but in reverse phase, and then it decays again. Comparing these data with those simulated using the SCG constitutive model, the effective shear modulus for aluminum shocked to 80 GPa is determined to be about 90 GPa, which is higher than the result given by Yu.

Relative frequencies of seismic main shocks after strong shocks in Italy

NASA Astrophysics Data System (ADS)

Gasperini, Paolo; Lolli, Barbara; Vannucci, Gianfranco

2016-10-01

We analysed a catalogue of Italian earthquakes, covering 55 yr of data from 1960 to 2014 with magnitudes homogeneously converted to Mw, to compute the time-dependent relative frequencies with which strong seismic shocks (4.0 ≤ Mw < 5.0), widely felt by the population, have been followed by main shocks (Mw ≥ 5.0) that threatened the health and the properties of the persons living in the epicentral area. Assuming the stationarity of the seismic release properties, such frequencies are estimates of the probabilities of potentially destructive shocks after the occurrence of future strong shocks. We compared them with the time-independent relative frequencies of random occurrence in terms of the frequency gain that is the ratio between the time-dependent and time-independent relative frequencies. The time-dependent relative frequencies vary from less than 1 per cent to about 20 per cent, depending on the magnitudes of the shocks and the time windows considered (ranging from minutes to years). They remain almost constant for a few hours after the strong shock and then decrease with time logarithmically. Strong earthquakes (with Mw ≥ 6.0) mainly occurred within two or three months of the strong shock. The frequency gains vary from about 10 000 for very short time intervals to less than 10 for a time interval of 2 yr. Only about 1/3 of main shocks were preceded by at least a strong shock in the previous day and about 1/2 in the previous month.

Differential expression of the Nrf2-linked genes in pediatric septic shock.

PubMed

Grunwell, Jocelyn R; Weiss, Scott L; Cvijanovich, Natalie Z; Allen, Geoffrey L; Thomas, Neal J; Freishtat, Robert J; Anas, Nick; Meyer, Keith; Checchia, Paul A; Shanley, Thomas P; Bigham, Michael T; Fitzgerald, Julie; Howard, Kelli; Frank, Erin; Harmon, Kelli; Wong, Hector R

2015-09-17

Experimental data from animal models of sepsis support a role for a transcription factor, nuclear erythroid-related factor 2 p45-related factor 2 (Nrf2), as a master regulator of antioxidant and detoxifying genes and intermediary metabolism during stress. Prior analysis of a pediatric septic shock transcriptomic database showed that the Nrf2 response is a top 5 upregulated signaling pathway in early pediatric septic shock. We conducted a focused analysis of 267 Nrf2-linked genes using a multicenter, genome-wide expression database of 180 children with septic shock 10 years of age or younger and 53 healthy controls. The analysis involved RNA isolated from whole blood within 24 h of pediatric intensive care unit admission for septic shock and a false discovery rate of 5 %. We compared differentially expressed genes from (1) patients with septic shock and healthy controls and (2) across validated gene expression-based subclasses of pediatric septic shock (endotypes A and B) using several bioinformatic methods. We found upregulation of 123 Nrf2-linked genes in children with septic shock. The top gene network represented by these genes contained primarily enzymes with oxidoreductase activity involved in cellular lipid metabolism that were highly connected to the peroxisome proliferator activated receptor and the retinoic acid receptor families. Endotype A, which had higher organ failure burden and mortality, exhibited a greater downregulation of Nrf2-linked genes than endotype B, with 92 genes differentially regulated between endotypes. Our findings indicate that Nrf2-linked genes may contribute to alterations in oxidative signaling and intermediary metabolism in pediatric septic shock.

Long-term outcomes after severe shock.

PubMed

Pratt, Cristina M; Hirshberg, Eliotte L; Jones, Jason P; Kuttler, Kathryn G; Lanspa, Michael J; Wilson, Emily L; Hopkins, Ramona O; Brown, Samuel M

2015-02-01

Severe shock is a life-threatening condition with very high short-term mortality. Whether the long-term outcomes among survivors of severe shock are similar to long-term outcomes of other critical illness survivors is unknown. We therefore sought to assess long-term survival and functional outcomes among 90-day survivors of severe shock and determine whether clinical predictors were associated with outcomes. Seventy-six patients who were alive 90 days after severe shock (received ≥1 μg/kg per minute of norepinephrine equivalent) were eligible for the study. We measured 3-year survival and long-term functional outcomes using the Medical Outcomes Study 36-Item Short-Form Health Survey, the EuroQOL 5-D-3L, the Hospital Anxiety and Depression Scale, the Impact of Event Scale-Revised, and an employment instrument. We also assessed the relationship between in-hospital predictors and long-term outcomes. The mean long-term survival was 5.1 years; 82% (62 of 76) of patients survived, of whom 49 were eligible for follow-up. Patients who died were older than patients who survived. Thirty-six patients completed a telephone interview a mean of 5 years after hospital admission. The patients' Physical Functioning scores were below U.S. population norms (P < 0.001), whereas mental health scores were similar to population norms. Nineteen percent of the patients had symptoms of depression, 39% had symptoms of anxiety, and 8% had symptoms of posttraumatic stress disorder. Thirty-six percent were disabled, and 17% were working full-time. Early survivors of severe shock had a high 3-year survival rate. Patients' long-term physical and psychological outcomes were similar to those reported for cohorts of less severely ill intensive care unit survivors. Anxiety and depression were relatively common, but only a few patients had symptoms of posttraumatic stress disorder. This study supports the observation that acute illness severity does not determine long-term outcomes. Even extremely

Dopamine in the management of shock.

PubMed Central

Thompson, W L

1977-01-01

Shock is a syndrome with serious prognostic implications--the harbinger of death. Hypoperfusion of essential organs is common, though total blood flow may be significantly greater than normal. Specific therapy is directed to the specific inciting event--infection, abscess, tamponade, &c. Symptomatic therapy keeps the patient alive until we discover the specific problem or until he recovers spontaneously. The intravascular volume must be carefully monitored and corrected, using the pulmonary wedge pressure as the principal guide, and colloid osmotic pressure must be maintained. If the patient does not respond to volume augmentation alone then inotropic drugs may be needed, and of these dopamine is a selective vasodilator which redirects blood flow to the critical organs. The outstanding challenge in shock is the maldistribution of perfusion in the microvasculature. Although this may be ameliorated by the early administration of large doses of glucocorticoids, there is little convincing that these drugs constitute more than supportive therapy. Of greatest importance is reevaluation, reevaluation, and reevaluation. The patient in shock becomes a new patient every five minutes. Drugs that formerly worked, doses previously optimal--these are no guide because the situation changes so rapidly. The principles of management are to monitor vital functions, constantly vary drugs and doses, and continually attempt to put right all the parameters measured. This strategy will be more effective when we know what parameters to measure. PMID:264200

The thermal and deformational history of apollo 15418, A partly shock-melted lunar breccia

USGS Publications Warehouse

Nord, G.L.; Christie, J.M.; Lally, J.S.; Heuer, A.H.

1977-01-01

A thermal and mechanical history of lunar gabbroic anorthosite 15418 (1140g) has been deduced from petrographic examination of both exterior and interior thin sections and electron microprobe analysis and transmission electron microscopy of interior thin sections. We suggest that the rock underwent two major shock events - an early brecciation and annealing that produced a recrystallized breccia, followed by a second shock event that melted the surface of the rock, vitrified the interior plagioclase and heavily deformed the mafic phases. This latter shock even was also followed by annealing which crystallized the shock-produced glass and promoted recovery and recrystallization of the deformed crystalline phases. The complex mechanical and thermal history of 15418 compared with other ANT suite rocks at Spur Crater suggests that it had a different provenance. ?? 1977 D. Reidel Publishing Company, Dordrecht-Holland.

Curious kinetic behavior in silica polymorphs solves seifertite puzzle in shocked meteorite

PubMed Central

Kubo, Tomoaki; Kato, Takumi; Higo, Yuji; Funakoshi, Ken-ichi

2015-01-01

The presence of seifertite, one of the high-pressure polymorphs of silica, in achondritic shocked meteorites has been problematic because this phase is thermodynamically stable at more than ~100 GPa, unrealistically high-pressure conditions for the shock events in the early solar system. We conducted in situ x-ray diffraction measurements at high pressure and temperatures, and found that it metastably appears down to ~11 GPa owing to the clear difference in kinetics between the metastable seifertite and stable stishovite formations. The temperature-insensitive but time-sensitive kinetics for the formation of seifertite uniquely constrains that the critical shock duration and size of the impactor on differentiated parental bodies are at least ~0.01 s and ~50 to 100 m, respectively, from the presence of seifertite. PMID:26601182

Measurement and Analysis of the Extreme Physical Shock Environment Experienced by Crane-Mounted Radiation Detection Systems.

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

Boyd, M; Erchinger, J; Marianno, C

Potentially, radiation detectors at ports of entry could be mounted on container gantry crane spreaders to monitor cargo containers entering and leaving the country. These detectors would have to withstand the extreme physical environment experienced by these spreaders during normal operations. Physical shock data from the gable ends of a spreader were recorded during the loading and unloading of a cargo ship with two Lansmont SAVER 9X30 units (with padding) and two PCB Piezotronics model 340A50 accelerometers (hard mounted). Physical shocks in the form of rapid acceleration were observed in all accelerometer units with values ranging from 0.20 g’s tomore » 199.99 g’s. The majority of the shocks for all the Lansmont and PCB accelerometers were below 50 g’s. The Lansmont recorded mean shocks of 21.83 ± 13.62 g’s and 24.78 ± 11.49 g’s while the PCB accelerometers experienced mean shocks of 34.39 ± 25.51 g’s and 41.77 ± 22.68 g’s for the landside and waterside units, respectively. Encased detector units with external padding should be designed to withstand at least 200 g’s of acceleration without padding and typical shocks of 30 g’s with padding for mounting on a spreader.« less

Sepsis in Obstetrics: Clinical Features and Early Warning Tools.

PubMed

Parfitt, Sheryl E; Bogat, Mary L; Hering, Sandra L; Ottley, Charlotte; Roth, Cheryl

Morbidity and mortality associated with sepsis has gained widespread attention on a local, state, and national level, yet, it remains a complicated disorder that can be difficult to identify in a timely manner. Sepsis in obstetric patients further complicates the diagnosis as alterations in physiology related to pregnancy can mask sepsis indicators normally seen in the general population. If early signs of sepsis go unrecognized, septic shock can develop, leading to organ dysfunction and potential death. Maternal early warning tools have been designed to assist clinicians in recognizing early indications of illness. Through use of clinical pathway-specific tools, disease processes may be detected early, subsequently benefitting patients with aggressive treatment management and intervention.This article is the second in a series of three that discuss the importance of sepsis and septic shock in pregnancy. Risk factors, causes of sepsis, signs and symptoms, and maternal early warning tools are discussed.

Shock Pressures, Temperatures and Durations in L Chondrites: Constraints from Shock-Vein Mineralogy

NASA Astrophysics Data System (ADS)

Xie, Z.; Aramovish Weaver, C.; Decarli, P. S.; Sharp, T. G.

2003-12-01

Shock effects in meteorites provide a record of major impact events on meteorite parent bodies. Shock veins in chondrites, which result from local melting during shock loading, are the location of all high-pressure minerals. Shock veins contain igneous assemblages, produced by the crystallization of shock-induced melt, and metamorphic assemblages, produced by solid-state transformation in entrained host-rock clasts and wall rock. The mineralogy, distribution of high-pressure minerals and microstructures in shock veins provide a record of crystallization pressures and quench histories that can be used to constrain shock pressures and pulse duration. Here we report mineralogical and microstructural studies of shock-induced melt veins in L chondrites that provide insight into the impact history of the L-chondrite parent body. Eight L6 chondrites were investigated using FESEM and TEM and Raman spectroscopy: RC 106 (S6), Tenham (S6), Umbarger (S4-S6), Roy (S3-S5), Ramsdorf (S4), Kunashak (S4), Nakhon Pathon (S4) and La Lande (S4). Igneous melt-vein assemblages, combined with published phase equilibrium data (Agee et al. 1996), indicate crystallization pressures from less than 2.5 GPa for Kunashack and LaLande to approximately 25 GPa for Tenham. Because shock veins quench primarily by thermal conduction, crystallization starts at vein edges and progresses inward. Variation in the igneous assemblage across shock veins, combined with thermal modelling, provides constraints on quench times and pressure variation during quench. Most samples appear to have crystallized prior to shock release, whereas Kunashack and LaLande apparently crystallized after pressure release. RC 106 and Tenham (both S6), which have thick melt veins with uniform igneous assemblages, crystallized under equilibrium shock pressures of approximately 22-25 GPa during shock events that lasted at least 500 ms and 50ms, respectively. The fact that S6 samples do not appear to have crystallized at a pressures

Anti-Shock Garment

NASA Technical Reports Server (NTRS)

1996-01-01

Ames Research Center developed a prototype pressure suit for hemophiliac children, based on research of astronauts' physiological responses in microgravity. Zoex Corporation picked up the design and patents and developed an anti-shock garment for paramedic use. Marketed by Dyna Med, the suit reverses the effect of shock on the body's blood distribution by applying counterpressure to the legs and abdomen, returning blood to vital organs and stabilizing body pressure until the patient reaches a hospital. The DMAST (Dyna Med Anti-Shock Trousers) employ lower pressure than other shock garments, and are non-inflatable.

Suppressive and Facilitative Effects of Shock Intensity and Interresponse Times Followed by Shock

ERIC Educational Resources Information Center

Everly, Jessica B.; Perone, Michael

2012-01-01

Although response-dependent shock often suppresses responding, response facilitation can occur. In two experiments, we examined the suppressive and facilitative effects of shock by manipulating shock intensity and the interresponse times that produced shock. Rats' lever presses were reinforced on a variable-interval 40-s schedule of food…

Exposure to Externalizing Peers in Early Childhood: Homophily and Peer Contagion Processes.

ERIC Educational Resources Information Center

Hanish, Laura D.; Martin, Carol Lynn; Fabes, Richard A.; Leonard, Stacie; Herzog, Melissa

2005-01-01

Guided by a transactional model, we examined the predictors and effects of exposure to externalizing peers in a low-risk sample of preschoolers and kindergarteners. On the basis of daily observations of peer interactions, we calculated measures of total exposure to externalizing peers and measures of exposure to same- and other-sex externalizing…

Miniature shock tube for laser driven shocks.

PubMed

Busquet, Michel; Barroso, Patrice; Melse, Thierry; Bauduin, Daniel

2010-02-01

We describe in this paper the design of a miniature shock tube (smaller than 1 cm(3)) that can be placed in a vacuum vessel and allows transverse optical probing and longitudinal backside extreme ultraviolet emission spectroscopy in the 100-500 A range. Typical application is the study of laser launched radiative shocks, in the framework of what is called "laboratory astrophysics."

The role of the brain-derived neurotrophic factor genotype and parenting in early life in predicting externalizing and internalizing symptoms in children with attention-deficit hyperactivity disorder.

PubMed

Park, Subin; Kim, Bung-Nyun; Kim, Jae-Won; Jung, Yeon-Kyung; Lee, Jin; Shin, Min-Sup; Yoo, Hee Jeong; Cho, Soo-Churl

2014-11-25

We aimed to determine whether early parenting is associated with externalizing and internalizing symptoms in children with attention-deficit hyperactivity disorder (ADHD) and whether such an association is affected by the brain-derived neurotrophic factor (BDNF) val66met polymorphism. The participants included 92 patients with ADHD aged 6-15 years. Measures of parenting in early life and externalizing and internalizing symptoms and the genotype of the BDNF Val66Met polymorphism were obtained. The degree to which the baby's autonomy was allowed was significantly and negatively correlated with the CDI scores in ADHD children (r = -0.38, p = 0.005). After adjusting for the child's gender, the child's age, the family's gross annual income, and the maternal education level, there was a significant interaction for the BDNF genotype and mother's positive feelings about caring in relation to the development of childhood anxiety/depression in ADHD children (F = 2.51, p = 0.011). Our results provide evidence of an interaction between the BDNF met allele and early parenting on the development of depression/anxiety symptoms.

Radiation- and pair-loaded shocks

NASA Astrophysics Data System (ADS)

Lyutikov, Maxim

2018-06-01

We consider the structure of mildly relativistic shocks in dense media, taking into account the radiation and pair loading, and diffusive radiation energy transfer within the flow. For increasing shock velocity (increasing post-shock temperature), the first important effect is the efficient energy redistribution by radiation within the shock that leads to the appearance of an isothermal jump, whereby the flow reaches the final state through a discontinuous isothermal transition. The isothermal jump, on scales much smaller than the photon diffusion length, consists of a weak shock and a quick relaxation to the isothermal conditions. Highly radiation-dominated shocks do not form isothermal jump. Pair production can mildly increase the overall shock compression ratio to ≈10 (4 for matter-dominated shocks and 7 of the radiation-dominated shocks).

[Whole-blood transfusion for hemorrhagic shock resuscitation: two cases in Djibouti].

PubMed

Cordier, P Y; Eve, O; Dehan, C; Topin, F; Menguy, P; Bertani, A; Massoure, P L; Kaiser, E

2012-01-01

Hemorrhagic shock requires early aggressive treatment, including transfusion of packed red blood cells and hemostatic resuscitation. In austere environments, when component therapy is not available, warm fresh whole-blood transfusion is a convenient treatment. It provides red blood cells, clotting factors, and functional platelets. Therefore it is commonly used in military practice to treat hemorrhagic shock in combat casualties. At Bouffard Hospital Center in Djibouti, the supply of packed red blood cells is limited, and apheresis platelets are unavailable. We used whole blood transfusion in two civilian patients with life-threatening non-traumatic hemorrhages. One had massive bleeding caused by disseminated intravascular coagulation due to septic shock; the second was a 39 year-old pregnant woman with uterine rupture. In both cases, whole blood transfusion (twelve and ten 500 mL bags respectively), combined with etiological treatment, enabled coagulopathy correction, hemorrhage control, and satisfactory recovery.

Shock tubes and waves; Proceedings of the Fourteenth International Symposium on Shock Tubes and Shock Waves, University of Sydney, Sydney, Australia, August 19-22, 1983

NASA Astrophysics Data System (ADS)

Archer, R. D.; Milton, B. E.

Techniques and facilities are examined, taking into account compressor cascades research using a helium-driven shock tube, the suppression of shocks on transonic airfoils, methods of isentropically achieving superpressures, optimized performance of arc heated shock tubes, pressure losses in free piston driven shock tubes, large shock tubes designed for nuclear survivability testing, and power-series solutions of the gasdynamic equations for Mach reflection of a planar shock by a wedge. Other subjects considered are related to aerodynamics in shock tubes, shocks in dusty gases, chemical kinetics, and lasers, plasmas, and optical methods. Attention is given to vapor explosions and the blast at Mt. St. Helens, combustion reaction mechanisms from ignition delay times, the development and use of free piston wind tunnels, models for nonequilibrium flows in real shock tubes, air blast measuring techniques, finite difference computations of flow about supersonic lifting bodies, and the investigation of ionization relaxation in shock tubes.

Viridans streptococcal shock syndrome during bone marrow transplantation.

PubMed

Martino, R; Manteiga, R; Sánchez, I; Brunet, S; Sureda, A; Badell, I; Argilés, B; Subirá, M; Bordes, R; Domingo-Albós, A

1995-01-01

Of 320 patients receiving a marrow transplant at the Hospital de Sant Pau between 1986 and 1992, 12% developed viridans streptococcal bacteremia during severe neutropenia. Five of these patients (13%) developed a rapidly progressive fatal shock syndrome characterized by bilateral pulmonary infiltrates, acute respiratory failure (ARDS) and septic shock early in the transplantation course (6 or 7 days posttransplantation). All patients were transplanted for acute leukemia in remission, and 2 received an allogeneic and 3 an autologous transplant. Four of these subjects were younger than 15 years of age and all had received cyclophosphamide and total body irradiation as conditioning regimen for marrow transplantation. All 5 patients died, and postmortem examinations revealed diffuse pulmonary lesions characteristic of the ARDS. These observations contribute to defining the clinical and pathologic characteristics of this serious complication of intensive anticancer treatment.

[Septic shock due to infective endocarditis of stimulation system of implantable cardioverter-defibrillator].

PubMed

Porubčinová, I; Porubčin, S; Stančák, B; Beňa, M; Sabol, F

2012-01-01

We present a case of a 60-year old patient hospitalized at the Department of Infectious Diseases and Travel Medicine, Medical faculty of UPJS and L. Pasteurs University Hospital in Kosice with suspected gastroenteritis. The patient was admitted to an intensive care unit because of the signs of septic shock. Within one hour from admission, the patient was administered early goal directed therapy for septic shock. Subsequently, infectious endocarditis of stimulation electrodes and tricuspid valve was identified as the origin of the infection. The stimulation system was then explanted from a stabilized and afebrile patient at the Department of cardiac Surgery of Eastern Slovak Institute of Cardiac and Vascular Diseases in Kosice. This case should emphasise frequently atypical course of this serious disease and the need for early identification of severe sepsis to enable timely management to affect mortality.

Initial decomposition of the condensed-phase β-HMX under shock waves: molecular dynamics simulations.

PubMed

Ge, Ni-Na; Wei, Yong-Kai; Ji, Guang-Fu; Chen, Xiang-Rong; Zhao, Feng; Wei, Dong-Qing

2012-11-26

We have performed quantum-based multiscale simulations to study the initial chemical processes of condensed-phase octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under shock wave loading. A self-consistent charge density-functional tight-binding (SCC-DFTB) method was employed. The results show that the initial decomposition of shocked HMX is triggered by the N-NO(2) bond breaking under the low velocity impact (8 km/s). As the shock velocity increases (11 km/s), the homolytic cleavage of the N-NO(2) bond is suppressed under high pressure, the C-H bond dissociation becomes the primary pathway for HMX decomposition in its early stages. It is accompanied by a five-membered ring formation and hydrogen transfer from the CH(2) group to the -NO(2) group. Our simulations suggest that the initial chemical processes of shocked HMX are dependent on the impact velocity, which gain new insights into the initial decomposition mechanism of HMX upon shock loading at the atomistic level, and have important implications for understanding and development of energetic materials.

Multipoint study of interplanetary shocks

NASA Astrophysics Data System (ADS)

Blanco-Cano, Xochitl; Kajdic, Primoz; Russell, Christopher T.; Aguilar-Rodriguez, Ernesto; Jian, Lan K.; Luhmann, Janet G.

2016-04-01

Interplanetary (IP) shocks are driven in the heliosphere by Interplanetary Coronal Mass Ejections (ICMEs) and Stream Interaction Regions (SIRs). These shocks perturb the solar wind plasma, and play an active role in the acceleration of ions to suprathermal energies. Shock fronts evolve as they move from the Sun. Their surfaces can be far from uniform and be modulated by changes in the ambient solar wind (magnetic field orientation, flow velocity), shocks rippling, and perturbations upstream and downstream from the shocks, i.e., electromagnetic waves. In this work we use multipoint observations from STEREO, WIND, and MESSENGER missions to study shock characteristics at different helio-longitudes and determine the properties of the waves near them. We also determine shock longitudinal extensions and foreshock sizes. The variations of geometry along the shock surface can result in different extensions of the wave and ion foreshocks ahead of the shocks, and in different wave modes upstream and downtream of the shocks. We find that the ion foreshock can extend up to 0.2 AU ahead of the shock, and that the upstream region with modified solar wind/waves can be very asymmetric.

Lunar highland meteorite Dhofar 026 and Apollo sample 15418: Two strongly shocked, partially melted, granulitic breccias

USGS Publications Warehouse

Cohen, B. A.; James, O.B.; Taylor, L.A.; Nazarov, M.A.; Barsukova, L.D.

2004-01-01

Studies of lunar meteorite Dhofar 026, and comparison to Apollo sample 15418, indicate that Dhofar 026 is a strongly shocked granulitic breccia (or a fragmental breccia consisting almost entirely of granulitic breccia clasts) that experienced considerable post-shock heating, probably as a result of diffusion of heat into the rock from an external, hotter source. The shock converted plagioclase to maskelynite, indicating that the shock pressure was between 30 and 45 GPa. The post-shock heating raised the rock's temperature to about 1200 ??C; as a result, the maskelynite devitrified, and extensive partial melting took place. The melting was concentrated in pyroxene-rich areas; all pyroxene melted. As the rock cooled, the partial melts crystallized with fine-grained, subophitic-poikilitic textures. Sample 15418 is a strongly shocked granulitic breccia that had a similar history, but evidence for this history is better preserved than in Dhofar 026. The fact that Dhofar 026 was previously interpreted as an impact melt breccia underscores the importance of detailed petrographic study in interpretation of lunar rocks that have complex textures. The name "impact melt" has, in past studies, been applied only to rocks in which the melt fraction formed by shock-induced total fusion. Recently, however, this name has also been applied to rocks containing melt formed by heating of the rocks by conductive heat transfer, assuming that impact is the ultimate source of the heat. We urge that the name "impact melt" be restricted to rocks in which the bulk of the melt formed by shock-induced fusion to avoid confusion engendered by applying the same name to rocks melted by different processes. ?? Meteoritical Society, 2004.

Infant-Mother Attachment and the Growth of Externalizing Problems across the Primary-School Years

ERIC Educational Resources Information Center

Pasco Fearon, R. M.; Belsky, Jay

2011-01-01

Background: Some contend that attachment insecurity increases risk for the development of externalizing behavior problems in children. Method: Latent-growth curve analyses were applied to data on 1,364 children from the NICHD Study of Early Child Care to evaluate the association between early attachment and teacher-rated externalizing problems…

The Impact of Parents, Child Care Providers, Teachers, and Peers on Early Externalizing Trajectories

PubMed Central

Silver, Rebecca B.; Measelle, Jeffrey R.; Armstrong, Jeffrey M.; Essex, Marilyn J.

2010-01-01

This study utilized growth mixture modeling to examine the impact of parents, child care providers, teachers, and peers on the prediction of distinct developmental patterns of classroom externalizing behavior in elementary school. Among 241 children, three groups were identified. 84.6% of children exhibited consistently low externalizing behavior. The externalizing behavior of the Chronic High group (5.8%) remained elevated throughout elementary school; it increased over time in the Low Increasing group (9.5%). Negative relationships with teachers and peers in the kindergarten classroom increased the odds of having chronically high externalizing behavior. Teacher–child conflict increased the likelihood of a developmental pattern of escalating externalizing behavior. Boys were overrepresented in the behaviorally risky groups, and no sex differences in trajectory types were found. PMID:21094398

Shock Corrugation by Rayleigh-Taylor Instability in Gamma-Ray Burst Afterglow Jets

NASA Astrophysics Data System (ADS)

Duffell, Paul C.; MacFadyen, Andrew I.

2014-08-01

Afterglow jets are Rayleigh-Taylor unstable and therefore turbulent during the early part of their deceleration. There are also several processes which actively cool the jet. In this Letter, we demonstrate that if cooling significantly increases the compressibility of the flow, the turbulence collides with the forward shock, destabilizing and corrugating it. In this case, the forward shock is turbulent enough to produce the magnetic fields responsible for synchrotron emission via small-scale turbulent dynamo. We calculate light curves assuming the magnetic field is in energy equipartition with the turbulent kinetic energy and discover that dynamic magnetic fields are well approximated by a constant magnetic-to-thermal energy ratio of 1%, though there is a sizeable delay in the time of peak flux as the magnetic field turns on only after the turbulence has activated. The reverse shock is found to be significantly more magnetized than the forward shock, with a magnetic-to-thermal energy ratio of the order of 10%. This work motivates future Rayleigh-Taylor calculations using more physical cooling models.

Astrophysically relevant radiatively cooled hypersonic bow shocks in nested wire arrays

NASA Astrophysics Data System (ADS)

Ampleford, David

2009-11-01

We have performed laboratory experiments which introduce obstructions into hypersonic plasma flows to study the formation of shocks. Astrophysical observations have demonstrated many examples of equivalent radiatively cooled bow shocks, for example the head of protostellar jets or supernova remnants passing through the interstellar medium or between discrete clumps in jets. Wire array z-pinches allow us to study quasi-planar radiatively cooled flows in the laboratory. The early stage of a wire array z-pinch implosion consists of a steady flow of the wire material towards the axis. Given a high rate of radiative cooling, these flows reach high sonic- Mach numbers, typically up to 5. The 2D nature of this configuration allows the insertion of obstacles into the flow, such as a concentric ``inner'' wire array, as has previously been studied for ICF research. Here we study the application of such a nested array to laboratory astrophysics where the inner wires act as obstructions perpendicular to the flow, and induce bow shocks. By varying the wire array material (W/Al), the significance of radiative cooling on these shocks can be controlled, and is shown to change the shock opening angle. As multiple obstructions are present, the experiments show the interaction of multiple bow shocks. It is also possible to introduce a magnetic field around the static object, increasing the opening angle of the shocks. Further experiments can be designed to control the flow density, magnetic field structure and obstruction locations. In collaboration with: S.V. Lebedev, M.E. Cuneo, C.A. Jennings, S.N. Bland, J.P. Chittenden, A. Ciardi, G.N. Hall, S.C. Bott, M. Sherlock, A. Frank, E. Blackman

The behavior of a compressible turbulent boundary layer in a shock-wave-induced adverse pressure gradient. Ph.D. Thesis - Washington Univ., Seattle, Aug. 1972

NASA Technical Reports Server (NTRS)

Rose, W. C.

1973-01-01

The results of an experimental investigation of the mean- and fluctuating-flow properties of a compressible turbulent boundary layer in a shock-wave-induced adverse pressure gradient are presented. The turbulent boundary layer developed on the wall of an axially symmetric nozzle and test section whose nominal free-stream Mach number and boundary-layer thickness Reynolds number were 4 and 100,000, respectively. The adverse pressure gradient was induced by an externally generated conical shock wave. Mean and time-averaged fluctuating-flow data, including the complete experimental Reynolds stress tensor and experimental turbulent mass- and heat-transfer rates are presented for the boundary layer and external flow, upstream, within and downstream of the pressure gradient. The mean-flow data include distributions of total temperature throughout the region of interest. The turbulent mixing properties of the flow were determined experimentally with a hot-wire anemometer. The calibration of the wires and the interpretation of the data are discussed. From the results of the investigation, it is concluded that the shock-wave - boundary-layer interaction significantly alters the turbulent mixing characteristics of the boundary layer.

Coronary artery dilatation in toxic shock-like syndrome: the Kawasaki disease shock syndrome.

PubMed

Yim, Deane; Ramsay, James; Kothari, Darshan; Burgner, David

2010-11-01

Kawasaki disease is a common systemic vasculitis of childhood that may result in life-threatening coronary artery abnormalities. Despite an overlap of clinical features with toxic shock syndrome, children with Kawasaki disease generally do not develop shock. We report two cases of older children who presented with a toxic shock-like illness, and were diagnosed with Kawasaki disease when coronary artery abnormalities were found on echocardiography, in keeping with the recently described 'Kawasaki disease shock syndrome'. Clinicians should consider Kawasaki disease in all children presenting with toxic shock and assess for coronary artery damage.

Measurement of the Shock Velocity and Symmetry History in Decaying Shock Pulses

NASA Astrophysics Data System (ADS)

Baker, Kevin; Milovich, Jose; Jones, Oggie; Robey, Harry; Smalyuk, Vladimir; Casey, Daniel; Celliers, Peter; Clark, Dan; Giraldez, Emilio; Haan, Steve; Hamza, Alex; Berzak-Hopkins, Laura; Jancaitis, Ken; Kroll, Jeremy; Lafortune, Kai; MacGowan, Brian; Macphee, Andrew; Moody, John; Nikroo, Abbas; Peterson, Luc; Raman, Kumar; Weber, Chris; Widmayer, Clay

2014-10-01

Decaying first shock pulses are predicted in simulations to provide more stable implosions and still achieve a low adiabat in the fuel, enabling a higher fuel compression similar to ``low foot'' laser pulses. The first step in testing these predictions was to measure the shock velocity for both a three shock and a four shock adiabat-shaped pulse in a keyhole experimental platform. We present measurements of the shock velocity history, including the decaying shock velocity inside the ablator, and compare it with simulations, as well as with previous low and high foot pulses. Using the measured pulse shape, the predicted adiabat from simulations is presented and compared with the calculated adiabat from low and high foot laser pulse shapes. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

Shock analysis - Three useful new relations. [collisionless hydromagnetic shocks in space plasmas

NASA Technical Reports Server (NTRS)

Smith, Edward J.; Burton, Marcia E.

1988-01-01

The behavior of collisionless hydromagnetic shocks in interplanetary space is considered analytically, with a focus on relations, implicit in the governing Rankine-Hugoniot equations, involving the magnetic field (B) and the plasma velocity (V). A moving reference frame aligned with the shock is employed, and expressions are derived which make it possible (1) to determine the speed of a shock of arbitrary orientation from upstream and downstream measurements of B and V; (2) to characterize the change in flow direction as the plasma crosses the shock in terms of the plasma beta, the Mach number, and the angle between the upstream field and the shock normal; and (3) to infer the third component of the upstream-downstream velocity jump from B and two-dimensional V measurements. These expressions are applied to ISEE-3 data on an interplanetary shock on April 5, 1979, and the results are presented in tables.

The Effects of FUV Radiation on C-Shocks: Implications for Water and Other O-bearing Species

NASA Astrophysics Data System (ADS)

Kaufman, Michael; Melick, Gary; Tolls, Volker

2015-08-01

Protostellar outflows have long been known to drive endothermic reactions that produce high abundances of oxygen-bearing species. Models of shocks in well-shielded gas made the strong prediction that essentially all of the pre-shock oxygen gets driven into water, so that the post-shock water abundances are order 10-4. Herschel observations, however, including those from the key program “Water in Star Forming Regions with Herschel (WISH)” show that for most sources, the shocked gas water abundances of are far lower, 10-7 - 10-5.This pattern of lower-than-predicted water abundance has led us to consider that our C-shock model (Kaufman & Neufeld 1996) is incomplete. In particular, we did not previously take into account that many outflow sources have higher than average far-ultraviolet radiation fields within their outflow cavities. Strong FUV radiation has important effects on the structure of C-shocks: the ionization fraction is larger than in well-shielded gas, decreasing the coupling length between neutrals and ions, and leading to higher temperatures and a lower breakdown speeds; the pre-shock gas composition, including the presence of ice mantles and the dominant charge carriers, is strongly affected; and abundant species such as water are diminished by photodissociation in the cooled down stream gas.In addition to the normal parameters of density, shock velocity, and magnetic field strength, we now include the external FUV field strength and the extinction between the FUV source and the shock. We use the results of a detailed PDR model to compute pre-shock chemical conditions, including the ionization fraction, the increase of which decreases the maximum velocities of C- shocks. FUV also keeps oxygen in the gas phase, making more available for H2O formarion ; however, photodissociation beyond the temperature peak keeps the average H2O abundance down. We present comparisons of our model results with the inferred water abundances and with observations of H2O

Shock wave treatment in medicine.

PubMed

Shrivastava, S K; Kailash

2005-03-01

Extracorporeal shock wave therapy in orthopedics and traumatology is still a young therapy method. Since the last few years the development of shock wave therapy has progressed rapidly. Shock waves have changed the treatment of urolithiasis substantially. Today shock waves are the first choice to treat kidney and urethral stones. Urology has long been the only medical field for shock waves in medicine. Meanwhile shock waves have been used in orthopedics and traumatology to treat insertion tendinitis, avascular necrosis of the head of femur and other necrotic bone alterations. Another field of shock wave application is the treatment of tendons, ligaments and bones on horses in veterinary medicine. In the present paper we discuss the basic theory and application of shock waves and its history in medicine. The idea behind using shock wave therapy for orthopedic diseases is the stimulation of healing in tendons, surrounding tissue and bones.

Infrared spectroscopy of interstellar shocks

NASA Technical Reports Server (NTRS)

Mckee, C. F.; Chernoff, D. F.; Hollenbach, D. J.

1984-01-01

Infrared emission lines from interstellar shocks provide valuable diagnostics for violent events in the interstellar medium, such as supernova remnants and mass outflow from young stellar objects. There are two types of interstellar shocks: in J shocks, gas properties 'jump' from their preshock to their postshock values in a shock front with a thickness equal to or less than one mean free path; radiation is emitted behind the shock front, primarily in the visible and ultraviolet, but with a few strong infrared lines, such as OI(63 microns). Such shocks occur in ionized or neutral atomic gas, or at high velocities (equal to or greater than 50 km/s) in molecular gas. In C shocks, gas is accelerated and heated by collisions between charged particles, which have a low concentration and are coupled to the magnetic field, and neutral particles; radiation is generated throughout the shock and is emitted almost entirely in infrared emission lines. Such shocks occur in weakly ionized molecular gas for shock velocities below about 50 km/s.

Mean arterial pressure target in patients with septic shock.

PubMed

Beloncle, Francois; Radermacher, Peter; Guerin, Claude; Asfar, Pierre

2016-07-01

In patients with septic shock, a mean arterial pressure higher than 65 mmHg is recommended by the Surviving Sepsis Campaign Guidelines. However, a precise mean arterial pressure target has not been delineated. The aim of this paper was to review the physiological rationale and clinical evidence for increasing mean arterial pressure in septic shock. A mean arterial pressure level lower than renal autoregulatory threshold may lead to renal dysfunction. However, adjusting macrocirculation objectives in particular after the early phase of septic shock may not correct established microcirculation impairments. Moreover, sympathetic over-stimulation due to high doses of vasopressor (needed to achieve high mean arterial pressure targets) may be associated with numerous harmful effects. Observational and small short term interventional studies did not provide a definitive answer to this question but suggested that a high mean arterial pressure (around 75-85 mmHg) may prevent acute kidney injury in some patients. The SEPSISPAM Trial, a large prospective, randomized, controlled study, compared the targets of High (i.e. 80 to 85 mm Hg) versus Low (i.e. 65 to 70 mm Hg) mean arterial pressure in patients with septic shock. The mortality was not different in the two groups. However in patients with chronic hypertension, there were significantly less renal failure in the high mean arterial pressure group than the low mean arterial pressure group.

The Relationship between External Job Mobility and Salary Attainment across Career Stages

ERIC Educational Resources Information Center

Lam, Simon S. K.; Ng, Thomas W. H.; Feldman, Daniel C.

2012-01-01

The current study examines the relationship between external job mobility and salary for employees in different career stages. Based on career stage and career timetable theories, we predict that external job mobility would generate the greatest salary benefits for early-career employees whereas external job mobility would generate fewer salary…

Sex-specific relationships among attachment security, social values, and sensation seeking in early adolescence: implications for adolescents' externalizing problem behaviour.

PubMed

Sarracino, Diego; Presaghi, Fabio; Degni, Silvia; Innamorati, Marco

2011-06-01

In early adolescence, attachment security reflects not only the quality of ongoing relationships with parents, but also how adolescents process social relationships with "others" - that is, their "social value orientation" - with possible implications for adolescents' risk-taking. In this study, a sample of Italian early adolescents were administered self-report measures in order to examine the relationships (a) between early adolescents' perceived attachment security to mothers and fathers, social values (related to family and the socio-cultural context), and sensation seeking (as a temperamental predisposition to risk-taking), and (b) between these variables and adolescents' externalizing problem behaviour. Adolescents were more securely attached to the same-sexed parent. Further, attachment security with the opposite-sexed parent predicted more conservative social value orientations, and lower levels of problem behaviour. In contrast, sensation seeking predicted self-enhancement and openness-to-change values to a greater extent, and, in girls, lower levels of attachment security to mothers and fathers. Copyright © 2010 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Spinal Cord Ischemia Secondary to Hypovolemic Shock

PubMed Central

Kapoor, Siddhant; Koh, Roy KM; Yang, Eugene WR; Hee, Hwan-Tak

2014-01-01

A 44-year-old male presented with symptoms of spinal cord compression secondary to metastatic prostate cancer. An urgent decompression at the cervical-thoracic region was performed, and there were no complications intraoperatively. Three hours postoperatively, the patient developed acute bilateral lower-limb paralysis (motor grade 0). Clinically, he was in class 3 hypovolemic shock. An urgent magnetic resonance imaging (MRI) was performed, showing no epidural hematoma. He was managed aggressively with medical therapy to improve his spinal cord perfusion. The patient improved significantly, and after one week, he was able to regain most of his motor functions. Although not commonly reported, spinal cord ischemia post-surgery should be recognized early, especially in the presence of hypovolemic shock. MRI should be performed to exclude other potential causes of compression. Spinal cord ischemia needs to be managed aggressively with medical treatment to improve spinal cord perfusion. The prognosis depends on the severity of deficits, and is usually favorable. PMID:25558328

Effective date of requirement for premarket approval for automated external defibrillator systems. Final rule.

PubMed

2015-01-29

The Food and Drug Administration (FDA or the Agency) is issuing a final order to require the filing of premarket approval applications (PMA) for automated external defibrillator (AED) systems, which consist of an AED and those AED accessories necessary for the AED to detect and interpret an electrocardiogram and deliver an electrical shock (e.g., pad electrodes, batteries, adapters, and hardware keys for pediatric use).

An Interactive, Design and Educational Tool for Supersonic External-Compression Inlets

NASA Technical Reports Server (NTRS)

Benson, Thomas J.

1994-01-01

A workstation-based interactive design tool called VU-INLET was developed for the inviscid flow in rectangular, supersonic, external-compression inlets. VU-INLET solves for the flow conditions from free stream, through the supersonic compression ramps, across the terminal normal shock region and the subsonic diffuser to the engine face. It calculates the shock locations, the capture streamtube, and the additive drag of the inlet. The inlet geometry can be modified using a graphical user interface and the new flow conditions recalculated interactively. Free stream conditions and engine airflow can also be interactively varied and off-design performance evaluated. Flow results from VU-INLET can be saved to a file for a permanent record, and a series of help screens make the simulator easy to learn and use. This paper will detail the underlying assumptions of the models and the numerical methods used in the simulator.

Shock Waves in Supernova Ejecta

NASA Astrophysics Data System (ADS)

Raymond, J. C.

2018-02-01

Astrophysical shock waves are a major mechanism for dissipating energy, and by heating and ionizing the gas they produce emission spectra that provide valuable diagnostics for the shock parameters, for the physics of collisionless shocks, and for the composition of the shocked material. Shocks in SN ejecta in which H and He have been burned to heavier elements behave differently than shocks in ordinary astrophysical gas because of their very large radiative cooling rates. In particular, extreme departures from thermal equilibrium among ions and electrons and from ionization equilibrium may arise. This paper discusses the consequences of the enhanced metal abundances for the structure and emission spectra of those shocks.

Collisions between quasi-parallel shocks

NASA Technical Reports Server (NTRS)

Cargill, Peter J.

1991-01-01

The collision between pairs of quasi-parallel shocks is examined using hybrid numerical simulations. In the interaction, the two shocks are transmitted through each other leaving behind a hot plasma with a population of particles with energies in excess of 40 E0, where E0 is the kinetic energy of particles in the shock frame prior to the collision. The energization is more efficient for quasi-parallel shocks than parallel shocks. Collisions between shocks of equal strengths are more efficient than those that are unequal. The results are of importance for phenomena during the impulsive phase of solar flares, in the distant solar wind and at planetary bow shocks.

Experts' recommendations for the management of cardiogenic shock in children.

PubMed

Brissaud, Olivier; Botte, Astrid; Cambonie, Gilles; Dauger, Stéphane; de Saint Blanquat, Laure; Durand, Philippe; Gournay, Véronique; Guillet, Elodie; Laux, Daniela; Leclerc, Francis; Mauriat, Philippe; Boulain, Thierry; Kuteifan, Khaldoun

2016-12-01

Cardiogenic shock which corresponds to an acute state of circulatory failure due to impairment of myocardial contractility is a very rare disease in children, even more than in adults. To date, no international recommendations regarding its management in critically ill children are available. An experts' recommendations in adult population have recently been made (Levy et al. Ann Intensive Care 5(1):52, 2015; Levy et al. Ann Intensive Care 5(1):26, 2015). We present herein recommendations for the management of cardiogenic shock in children, developed with the grading of recommendations' assessment, development, and evaluation system by an expert group of the Groupe Francophone de Réanimation et Urgences Pédiatriques (French Group for Pediatric Intensive Care and Emergencies). The recommendations cover four major fields of application such as: recognition of early signs of shock and the patient pathway, management principles and therapeutic goals, monitoring hemodynamic and biological variables, and circulatory support (indications, techniques, organization, and transfer criteria). Major principle care for children with cardiogenic shock is primarily based on clinical and echocardiographic assessment. There are few drugs reported as effective in childhood in the medical literature. The use of circulatory support should be facilitated in terms of organization and reflected in the centers that support these children. Children with cardiogenic shock are vulnerable and should be followed regularly by intensivist cardiologists and pediatricians. The experts emphasize the multidisciplinary nature of management of children with cardiogenic shock and the importance of effective communication between emergency medical assistance teams (SAMU), mobile pediatric emergency units (SMUR), pediatric emergency departments, pediatric cardiology and cardiac surgery departments, and pediatric intensive care units.

Shock break-out: how a GRB revealed the beginnings of a supernova.

PubMed

Blustin, Alexander J

2007-05-15

In February 2006, Swift caught a gamma-ray burst (GRB) in the act of turning into a supernova, and made the first ever direct observations of the break-out and early expansion of a supernova shock wave. GRB 060218 began with an exceptionally long burst of non-thermal gamma-rays, lasting over 2000s, as a jet erupted through the surface of the star. While this was in progress, an optically-thick thermal component from the shock wave of the supernova explosion grew to prominence, and we were able to track the mildly relativistic expansion of this shell as the blackbody peak moved from the X-rays into the UV and optical bands. The initial radius of the shock implied that it was a blue supergiant that had exploded, but the lack of hydrogen emission lines in the supernova spectrum indicated a more compact star. The most likely scenario is that the shock ploughed into the massive stellar wind of a Wolf-Rayet progenitor, with the shock breaking-out and becoming visible to us once it reached the radius where the wind became optically-thin. I present the Swift observations of this landmark event, and discuss the new questions and answers it leaves us with.

[Outpatient external dacryocystorhinostomy under regional anesthesia and sedation].

PubMed

Benatar-Haserfaty, J; Monleón de la Calle, M P; Sanz-López, A; Muriel García, A

2007-01-01

To assess the rate of early complications of outpatient external dacryocystorhinostomy (DCR) and patient satisfaction with the anesthetic technique. This prospective study enrolled 58 patients undergoing external DCR. We analyzed demographic variables, ASA physical status, level of sedation achieved, postoperative pain, systemic complications, intraoperative bleeding, duration of surgery, time until discharge home, and patient and surgeon satisfaction with the anesthetic technique. The mean (SD) level of satisfaction was 4.85 (0.80) points on the Iowa Satisfaction With Anesthesia Scale (ISAS). A positive association was found between postoperative pain and a lower ISAS score. There was also a positive association between use of rescue analgesia in the early postoperative period and a lower ISAS score. Mean blood loss per procedure was 178.9 (108.2) mL. The rate of minor systemic complications was 15.5%. The surgeon's rating of conditions in the surgical field was excellent or good in 89.6% of the cases. External DCR can be performed on an outpatient basis within a reasonable safety margin and with a low early postoperative complication rate. Patient satisfaction with anesthesia was high. Provision of preoperative information about the meaning of sedation, postoperative analgesia, and surgical bleeding are aspects to improve in this practice setting.

Semiautomated external defibrillators for in-hospital early defibrillation: a comparative study.

PubMed

Nocchi, Federico; Derrico, Pietro; Masucci, Gerardina; Capussotto, Carlo; Cecchetti, Corrado; Ritrovato, Matteo

2014-01-01

Semiautomated external defibrillators (AEDs) should be considered as a means to facilitate in-hospital early defibrillation (IHED) in areas where advanced life support rescuers are not readily available. In this study, we aimed to develop a checklist and a measurement protocol to evaluate and compare AEDs by assessing factors that may affect IHED. A clinical and technical comparison of six AEDs was performed. Technical specifications were analyzed, while an emergency team evaluated ergonomics and appropriateness for IHED at Bambino Gesù Children's Hospital. A measurement protocol was implemented, which aimed to assess the ability of defibrillators to recognize shockable and nonshockable rhythms, accuracy of delivered energy, and charging time. Designs of AEDs differed in several features which influence their appropriateness for IHED. Some units showed poor ergonomics and instructions/feedback for cardiopulmonary resuscitation. Differences between defibrillators in recognizing shockable and nonshockable rhythms emerged for polymorphic ventricular tachycardia waveforms and when the frequency and amplitude of input signals varied. Tests for accuracy revealed poor performances at low and high impedance levels for most AEDs. Notably, differences greater than 20 seconds were found in the time from power-on to "ready for discharge." The approach we used to assess AEDs allowed us to evaluate their appropriateness with respect to the organizational context, to measure their parameters, and to compare models. Results showed that ergonomics and/or performances (timing and accuracy) could be improved in each device.

Fractal attractors in economic growth models with random pollution externalities

NASA Astrophysics Data System (ADS)

La Torre, Davide; Marsiglio, Simone; Privileggi, Fabio

2018-05-01

We analyze a discrete time two-sector economic growth model where the production technologies in the final and human capital sectors are affected by random shocks both directly (via productivity and factor shares) and indirectly (via a pollution externality). We determine the optimal dynamics in the decentralized economy and show how these dynamics can be described in terms of a two-dimensional affine iterated function system with probability. This allows us to identify a suitable parameter configuration capable of generating exactly the classical Barnsley's fern as the attractor of the log-linearized optimal dynamical system.

WHEN SHOCK WAVES COLLIDE

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

Hartigan, P.; Liao, A. S.; Foster, J.

2016-06-01

Supersonic outflows from objects as varied as stellar jets, massive stars, and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures, and therefore a higher-excitation spectrum than does an oblique shock. In this paper, we summarize the results of a series of numerical simulations and laboratory experiments designed tomore » quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and subcritical angles, larger ones persist in these situations and can regrow if the intersection angle changes to become more favorable. The experimental and numerical results show that although Mach stems occur only over a limited range of intersection angles and size scales, within these ranges they are relatively robust, and hence are a viable explanation for variable bright knots observed in Hubble Space Telescope images at the intersections of some bow shocks in stellar jets.« less

When shock waves collide

DOE PAGES

Martinez, D.; Hartigan, P.; Frank, A.; ...

2016-06-01

Supersonic outflows from objects as varied as stellar jets, massive stars, and novae often exhibit multiple shock waves that overlap one another. When the intersection angle between two shock waves exceeds a critical value, the system reconfigures its geometry to create a normal shock known as a Mach stem where the shocks meet. Mach stems are important for interpreting emission-line images of shocked gas because a normal shock produces higher postshock temperatures, and therefore a higher-excitation spectrum than does an oblique shock. In this paper, we summarize the results of a series of numerical simulations and laboratory experiments designed tomore » quantify how Mach stems behave in supersonic plasmas that are the norm in astrophysical flows. The experiments test analytical predictions for critical angles where Mach stems should form, and quantify how Mach stems grow and decay as intersection angles between the incident shock and a surface change. While small Mach stems are destroyed by surface irregularities and subcritical angles, larger ones persist in these situations and can regrow if the intersection angle changes to become more favorable. Furthermore, the experimental and numerical results show that although Mach stems occur only over a limited range of intersection angles and size scales, within these ranges they are relatively robust, and hence are a viable explanation for variable bright knots observed in Hubble Space Telescope images at the intersections of some bow shocks in stellar jets.« less

Diaphragmless shock wave generators for industrial applications of shock waves

NASA Astrophysics Data System (ADS)

Hariharan, M. S.; Janardhanraj, S.; Saravanan, S.; Jagadeesh, G.

2011-06-01

The prime focus of this study is to design a 50 mm internal diameter diaphragmless shock tube that can be used in an industrial facility for repeated loading of shock waves. The instantaneous rise in pressure and temperature of a medium can be used in a variety of industrial applications. We designed, fabricated and tested three different shock wave generators of which one system employs a highly elastic rubber membrane and the other systems use a fast acting pneumatic valve instead of conventional metal diaphragms. The valve opening speed is obtained with the help of a high speed camera. For shock generation systems with a pneumatic cylinder, it ranges from 0.325 to 1.15 m/s while it is around 8.3 m/s for the rubber membrane. Experiments are conducted using the three diaphragmless systems and the results obtained are analyzed carefully to obtain a relation between the opening speed of the valve and the amount of gas that is actually utilized in the generation of the shock wave for each system. The rubber membrane is not suitable for industrial applications because it needs to be replaced regularly and cannot withstand high driver pressures. The maximum shock Mach number obtained using the new diaphragmless system that uses the pneumatic valve is 2.125 ± 0.2%. This system shows much promise for automation in an industrial environment.

Shock Detector for SURF model

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

Menikoff, Ralph

2016-01-11

SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

Noninvasive optoacoustic system for rapid diagnosis and management of circulatory shock

NASA Astrophysics Data System (ADS)

Petrov, Irene Y.; Kinsky, Michael; Petrov, Yuriy; Petrov, Andrey; Henkel, S. N.; Seeton, Roger; Esenaliev, Rinat O.; Prough, Donald S.

2013-03-01

Circulatory shock can lead to death or severe complications, if not promptly diagnosed and effectively treated. Typically, diagnosis and management of circulatory shock are guided by blood pressure and heart rate. However, these variables have poor specificity, sensitivity, and predictive value. Early goal-directed therapy in septic shock patients, using central venous catheterization (CVC), reduced mortality from 46.5% to 30%. However, CVC is invasive and complication-prone. We proposed to use an optoacoustic technique for noninvasive, rapid assessment of peripheral and central venous oxygenation. In this work we used a medical grade optoacoustic system for noninvasive, ultrasound image-guided measurement of central and peripheral venous oxygenation. Venous oxygenation during shock declines more rapidly in the periphery than centrally. Ultrasound imaging of the axillary [peripheral] and internal jugular vein [central] was performed using the Vivid e (GE Healthcare). We built an optoacoustic interface incorporating an optoacoustic transducer and a standard ultrasound imaging probe. Central and peripheral venous oxygenations were measured continuously in healthy volunteers. To simulate shock-induced changes in central and peripheral oxygenation, we induced peripheral vasoconstriction in the upper extremity by using a cooling blanket. Central and peripheral venous oxygenations were measured before (baseline) and after cooling and after rewarming. During the entire experiment, central venous oxygenation was relatively stable, while peripheral venous oxygenation decreased by 5-10% due to cooling and recovered after rewarming. The obtained data indicate that noninvasive, optoacoustic measurements of central and peripheral venous oxygenation may be used for diagnosis and management of circulatory shock with high sensitivity and specificity.

Effect of early goal-directed therapy on mortality in patients with severe sepsis or septic shock: a meta-analysis of randomised controlled trials

PubMed Central

Yu, Hong; Chi, Dongmei; Wang, Siyang; Liu, Bin

2016-01-01

Objective To determine whether patients with severe sepsis or septic shock could benefit from a strict and early goal-directed therapy (EGDT) protocol recommended by Surviving Sepsis Campaign (SSC) Guidelines. Methods MEDLINE/PubMed, EMBASE/OVID and Cochrane Central Register of Controlled Trials (CENTRAL) were searched between March 1983 and March 2015. Eligible studies evaluated the outcomes of EGDT versus usual care or standard therapy in patients with severe sepsis or septic shock. The primary outcomes were mortality within 28 days, 60 days and 90 days. Included studies must report at least one metric of mortality. Results 5 studies that enrolled 4303 patients with 2144 in the EGDT group and 2159 in the control group were included in this meta-analysis. Overall, there were slight decreases of mortality within 28 days, 60 days and 90 days in the random-effect model in patients with severe sepsis or septic shock receiving EGDT resuscitation. However, none of the differences reached statistical significance (RR=0.86; 95% CI 0.69 to 1.06; p=0.16; p for heterogeneity=0.008, I2=71%; RR=0.94; 95% CI 0.81 to 1.10; p=0.46; p for heterogeneity=0.16, I2=43%; RR=0.98; 95% CI 0.88 to 1.10; p=0.75; p for heterogeneity=0.87, I2=0%, respectively). Conclusions The current meta-analysis pooled data from five RCTs and found no survival benefit of EGDT in patients with sepsis. However, the included trials are not sufficiently homogeneous and potential confounding factors in the negative trials (ProCESS, ARISE and ProMISe) might bias the results and diminish the treatment effect of EGDT. Further well-designed studies should eliminate all potential source of bias to determine if EGDT has a mortality benefit. PMID:26932135

Shock Isolation Elements Testing for High Input Loadings. Volume III. Mechanical Shock Isolation Elements.

DTIC Science & Technology

SHOCK ABSORBERS ), (*GUIDED MISSILE SILOS, SHOCK ABSORBERS ), (*SPRINGS, (*SHOCK(MECHANICS), REDUCTION), TORSION BARS, ELASTOMERS, DAMPING, EQUATIONS OF MOTION, MODEL TESTS, TEST METHODS, NUCLEAR EXPLOSIONS, HARDENING.

Shock metamorphism of ordinary chondrites

NASA Technical Reports Server (NTRS)

Stoeffler, Dieter; Keil, Klaus; Scott, Edward R. D.

1991-01-01

This study proposes a revised petrographic classification of progressive stages of shock metamorphism of 26 ordinary chondrites. Six stages of shock (S1 to S6) are defined on the basis of shock effects in olivine and plagioclase as recognized by thin section microscopy, and the characteristic shock effects of each shock stage are described. It is concluded that shock effects and the sequence of progressively increasing degrees of shock metamorphosis are very similar in H, L, and LL groups. Differences in the frequency distribution of shock stages are relatively minor. It is suggested that the collisional histories of the H, L, and LL parent bodies were similar. Petrologic type-3 chondrites are deficient in stages S4 and S6 and, with increasing petrologic type, the frequency of stages S4 to S6 increases. It is suggested that the more porous and volatile-rich Type-3 chondrites are subject to melting at a lower shock pressure than the nonporous chondrites of higher petrologic type. Stage S3 is the most abundant in nearly all petrologic types.

Shock waves data for minerals

NASA Technical Reports Server (NTRS)

Ahrens, Thomas J.; Johnson, Mary L.

1994-01-01

Shock compression of the materials of planetary interiors yields data which upon comparison with density-pressure and density-sound velocity profiles constrain internal composition and temperature. Other important applications of shock wave data and related properties are found in the impact mechanics of terrestrial planets and solid satellites. Shock wave equation of state, shock-induced dynamic yielding and phase transitions, and shock temperature are discussed. In regions where a substantial phase change in the material does not occur, the relationship between the particle velocity, U(sub p), and the shock velocity, U(sub s), is given by U(sub s) = C(sub 0) + S U(sub p), where C(sub 0) is the shock velocity at infinitesimally small particle velocity, or the ambient pressure bulk sound velocity. Numerical values for the shock wave equation of state for minerals and related materials of the solar system are provided.

Shock-induced termination of reentrant cardiac arrhythmias: Comparing monophasic and biphasic shock protocols

NASA Astrophysics Data System (ADS)

Bragard, Jean; Simic, Ana; Elorza, Jorge; Grigoriev, Roman O.; Cherry, Elizabeth M.; Gilmour, Robert F.; Otani, Niels F.; Fenton, Flavio H.

2013-12-01

In this article, we compare quantitatively the efficiency of three different protocols commonly used in commercial defibrillators. These are based on monophasic and both symmetric and asymmetric biphasic shocks. A numerical one-dimensional model of cardiac tissue using the bidomain formulation is used in order to test the different protocols. In particular, we performed a total of 4.8 × 106 simulations by varying shock waveform, shock energy, initial conditions, and heterogeneity in internal electrical conductivity. Whenever the shock successfully removed the reentrant dynamics in the tissue, we classified the mechanism. The analysis of the numerical data shows that biphasic shocks are significantly more efficient (by about 25%) than the corresponding monophasic ones. We determine that the increase in efficiency of the biphasic shocks can be explained by the higher proportion of newly excited tissue through the mechanism of direct activation.

Velocity profiles of interplanetary shocks

NASA Technical Reports Server (NTRS)

Cane, H. V.

1983-01-01

The type 2 radio burst was identified as a shock propagating through solar corona. Radio emission from shocks travelling through the interplanetary (IP) medium was observed. Using the drift rates of IP type II bursts the velocity characteristics of eleven shocks were investigated. It is indicated that shocks in the IP medium undergo acceleration before decelerating and that the slower shocks take longer to attain their maximum velocity.

Examining platelet-fibrin interactions during traumatic shock in a swine model using platelet contractile force and clot elastic modulus.

PubMed

White, Nathan J; Martin, Erika J; Brophy, Donald F; Ward, Kevin R

2011-07-01

A significant proportion of severely injured patients develop early coagulopathy, characterized by abnormal clot formation, which impairs resuscitation and increases mortality. We have previously demonstrated an isolated decrease in clot strength by thrombelastography in a swine model of nonresuscitated traumatic shock. In order to more closely examine platelet-fibrin interactions in this setting, we define the observed decrease in clot strength in terms of platelet-induced clot contraction and clot elastic modulus using the Hemostasis Analysis System (HAS) (Hemodyne Inc., Richmond, Virginia, USA). Whole blood was sampled for HAS measurements, metabolic measurements, cell counts, and fibrinogen concentration at baseline prior to injury and again at a predetermined level of traumatic shock defined by oxygen debt. Male swine (N=17) received femur fracture and controlled arterial hemorrhage to achieve an oxygen debt of 80 ml/kg. Platelet counts were unchanged, but fibrinogen concentration was reduced significantly during shock (167.6 vs. 66.7 mg/dl, P=0.0007). Platelet contractile force generated during clot formation did not change during shock (11.7 vs. 10.4 kdynes, P=0.41), but clot elastic modulus was dynamically altered, resulting in a lower final value (22.9 vs. 17.3 kdynes/cm, P<0.0001). In this model of traumatic shock, platelet function was preserved, whereas terminal clot elastic modulus was reduced during shock in a manner most consistent with early changes in the mechanical properties of the developing fibrin fiber network.

Monte Carlo simulation of a near-continuum shock-shock interaction problem

NASA Technical Reports Server (NTRS)

Carlson, Ann B.; Wilmoth, Richard G.

1992-01-01

A complex shock interaction is calculated with direct simulation Monte Carlo (DSMC). The calculation is performed for the near-continuum flow produced when an incident shock impinges on the bow shock of a 0.1 in. radius cowl lip for freestream conditions of approximately Mach 15 and 35 km altitude. Solutions are presented both for a full finite-rate chemistry calculation and for a case with chemical reactions suppressed. In each case, both the undisturbed flow about the cowl lip and the full shock interaction flowfields are calculated. Good agreement has been obtained between the no-chemistry simulation of the undisturbed flow and a perfect gas solution obtained with the viscous shock-layer method. Large differences in calculated surface properties when different chemical models are used demonstrate the necessity of adequately representing the chemistry when making surface property predictions. Preliminary grid refinement studies make it possible to estimate the accuracy of the solutions.

A VERY DEEP CHANDRA OBSERVATION OF THE GALAXY GROUP NGC 5813: AGN SHOCKS, FEEDBACK, AND OUTBURST HISTORY

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

Randall, S. W.; Nulsen, P. E. J.; Jones, C.

2015-06-01

We present results from a very deep (650 ks) Chandra X-ray observation of the galaxy group NGC 5813, the deepest Chandra observation of a galaxy group to date. This system uniquely shows three pairs of collinear cavities, with each pair associated with an unambiguous active galactic nucleus (AGN) outburst shock front. The implied mean kinetic power is roughly the same for each outburst, demonstrating that the average AGN kinetic luminosity can remain stable over long timescales (∼50 Myr). The two older outbursts have larger, roughly equal total energies as compared with the youngest outburst, implying that the youngest outburst ismore » ongoing. We find that the gas radiative cooling rate and mean shock heating rate are well balanced at each shock front, suggesting that shock heating alone is sufficient to offset cooling and establish AGN/intracluster medium (ICM) feedback within at least the central 30 kpc. This heating takes place roughly isotropically and most strongly at small radii, as is required for feedback to operate. We suggest that shock heating may play a significant role in AGN feedback at smaller radii in other systems, where weak shocks are more difficult to detect. We find non-zero shock front widths that are too large to be explained by particle diffusion. Instead, all measured widths are consistent with shock broadening due to propagation through a turbulent ICM with a mean turbulent speed of ∼70 km s{sup −1}. Finally, we place lower limits on the temperature of any volume-filling thermal gas within the cavities that would balance the internal cavity pressure with the external ICM.« less

Initial resuscitation and management of pediatric septic shock

PubMed Central

Martin, Kelly; Weiss, Scott L.

2015-01-01

The pediatric sepsis syndrome remains a common cause of morbidity, mortality, and health care utilization costs worldwide. The initial resuscitation and management of pediatric sepsis is focused on 1) rapid recognition of abnormal tissue perfusion and restoration of adequate cardiovascular function, 2) eradication of the inciting invasive infection, including prompt administration of empiric broad-spectrum antimicrobial medications, and 3) supportive care of organ system dysfunction. Efforts to improve early and aggressive initial resuscitation and ongoing management strategies have improved outcomes in pediatric severe sepsis and septic shock, though many questions still remain as to the optimal therapeutic strategies for many patients. In this article, we will briefly review the definitions, epidemiology, clinical manifestations, and pathophysiology of sepsis and provide an extensive overview of both current and novel therapeutic strategies used to resuscitate and manage pediatric patients with severe sepsis and septic shock. PMID:25604591

Health shocks and retirement: the role of welfare state institutions.

PubMed

Datta Gupta, Nabanita; Larsen, Mona

2007-09-01

We investigate the effect of an acute health shock on retirement among elderly male workers in Denmark, 1991-1999, and in particular whether various welfare state programs and institutions impinge on the retirement effect. The results show that an acute health event increases the retirement chances of elderly male workers by 8%, and that this increase in the baseline retirement probability is not affected by eligibility to early exit programs and persists even after accounting for selection due to take-up of disability pension. Neither is it affected by the relatively long duration of sickness benefits in Denmark nor by the promotion of corporate social responsibility initiatives since the mid-1990s. In the late 1990s, however, the retirement rate following a health shock is reduced to 3% with the introduction of the subsidized employment program ( fleksjob ) but this effect is on the margin of being significant. For the most part, the retirement effect following a health shock seems to be immune to the availability of a multitude of government programs for older workers in Denmark.

Survival without sequelae after prolonged cardiopulmonary resuscitation after electric shock.

PubMed

Motawea, Mohamad; Al-Kenany, Al-Sayed; Hosny, Mostafa; Aglan, Omar; Samy, Mohamad; Al-Abd, Mohamed

2016-03-01

"Electrical shock is the physiological reaction or injury caused by electric current passing through the human body. It occurs upon contact of a human body part with any source of electricity that causes a sufficient current through the skin, muscles, or hair causing undesirable effects ranging from simple burns to death." Ventricular fibrillation is believed to be the most common cause of death after electrical shock. "The ideal duration of cardiac resuscitation is unknown. Typically prolonged cardiopulmonary resuscitation is associated with poor neurologic outcomes and reduced long term survival. No consensus statement has been made and traditionally efforts are usually terminated after 15-30 minutes." The case under discussion seems worthy of the somewhat detailed description given. It is for a young man who survived after 65 minutes after electrical shock (ES) after prolonged high-quality cardiopulmonary resuscitation (CPR), multiple defibrillations, and artificial ventilation without any sequelae. Early start of adequate chest compressions and close adherence to advanced cardiac life support protocols played a vital role in successful CPR.

Shock initiation of nitromethane

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

Yoo, C.S.; Holmes, N.C.

1994-07-10

The shock initiation processes of nitromethane have been examined by using a fast time-resolved emission spectroscopy at a two-stage gas gun. A broad, but strong emission has been observed in a spectral range between 350 nm and 700 nm from the shocked nitromethane above 9 GPa. The temporal profile suggests that the shocked nitromethane detonates through three characteristic periods, namely an induction period, a shock initiation period, and a thermal explosion period. In this paper we will discuss the temporal and chemical characteristics of these periods and present the temperature of the shock-detonating nitromethane at pressures between 9 and 15more » GPa. [copyright]American Institute of Physics« less