The Overlap of Youth Violence Among Aggressive Adolescents with Past-Year Alcohol Use—A Latent Class Analysis: Aggression and Victimization in Peer and Dating Violence in an Inner City Emergency Department Sample

PubMed Central

Whiteside, Lauren K.; Ranney, Megan L.; Chermack, Stephen T.; Zimmerman, Marc A.; Cunningham, Rebecca M.; Walton, Maureen A.

2013-01-01

Objective: The purpose of this study was to identify overlap and violence types between peer and dating aggression and victimization using latent class analysis (LCA) among a sample of aggressive adolescents with a history of alcohol use and to identify risk and protective factors associated with each violence class. Method: From September 2006 to September 2009, a systematic sample of patients (14–18 years old) seeking care in an urban emergency department were approached. Adolescents reporting any past-year alcohol use and aggression completed a survey using validated measures including types of violence (severe and moderate aggression, severe and moderate victimization with both peers and dating partners). Using LCA, violence classes were identified; correlates of membership in each LCA class were determined. Results: Among this sample (n = 694), LCA identified three classes described as (a) peer aggression (PA) (52.2%), (b) peer aggression + peer victimization (PAPV) (18.6%), and (c) multiple domains of violence (MDV) (29.3%). Compared with those in the PA class, those in the PAPV class were more likely to be male, report injury in a fight, and have delinquent peers. Compared with the PA class, those in the MDV class were more likely to be female, African American, report injury in a fight, carry a weapon, experience negative consequences from alcohol use, and have delinquent peers and more family conflict. Compared with the PAPV class, those in the MDV class were likely to be female, African American, receive public assistance, carry a weapon, experience negative consequences from alcohol use, and use marijuana. Conclusions: There is extensive overlap of victimization and aggression in both peer and dating relationships. Also, those with high rates of violence across relationships have increased alcohol misuse and marijuana use. Thus, violence-prevention efforts should consider addressing concomitant substance use. PMID:23200158

Convergence and rate analysis of neural networks for sparse approximation.

PubMed

Balavoine, Aurèle; Romberg, Justin; Rozell, Christopher J

2012-09-01

We present an analysis of the Locally Competitive Algorithm (LCA), which is a Hopfield-style neural network that efficiently solves sparse approximation problems (e.g., approximating a vector from a dictionary using just a few nonzero coefficients). This class of problems plays a significant role in both theories of neural coding and applications in signal processing. However, the LCA lacks analysis of its convergence properties, and previous results on neural networks for nonsmooth optimization do not apply to the specifics of the LCA architecture. We show that the LCA has desirable convergence properties, such as stability and global convergence to the optimum of the objective function when it is unique. Under some mild conditions, the support of the solution is also proven to be reached in finite time. Furthermore, some restrictions on the problem specifics allow us to characterize the convergence rate of the system by showing that the LCA converges exponentially fast with an analytically bounded convergence rate. We support our analysis with several illustrative simulations.

Assessing measurement error in surveys using latent class analysis: application to self-reported illicit drug use in data from the Iranian Mental Health Survey.

PubMed

Khalagi, Kazem; Mansournia, Mohammad Ali; Rahimi-Movaghar, Afarin; Nourijelyani, Keramat; Amin-Esmaeili, Masoumeh; Hajebi, Ahmad; Sharif, Vandad; Radgoodarzi, Reza; Hefazi, Mitra; Motevalian, Abbas

2016-01-01

Latent class analysis (LCA) is a method of assessing and correcting measurement error in surveys. The local independence assumption in LCA assumes that indicators are independent from each other condition on the latent variable. Violation of this assumption leads to unreliable results. We explored this issue by using LCA to estimate the prevalence of illicit drug use in the Iranian Mental Health Survey. The following three indicators were included in the LCA models: five or more instances of using any illicit drug in the past 12 months (indicator A), any use of any illicit drug in the past 12 months (indicator B), and the self-perceived need of treatment services or having received treatment for a substance use disorder in the past 12 months (indicator C). Gender was also used in all LCA models as a grouping variable. One LCA model using indicators A and B, as well as 10 different LCA models using indicators A, B, and C, were fitted to the data. The three models that had the best fit to the data included the following correlations between indicators: (AC and AB), (AC), and (AC, BC, and AB). The estimated prevalence of illicit drug use based on these three models was 28.9%, 6.2% and 42.2%, respectively. None of these models completely controlled for violation of the local independence assumption. In order to perform unbiased estimations using the LCA approach, the factors violating the local independence assumption (behaviorally correlated error, bivocality, and latent heterogeneity) should be completely taken into account in all models using well-known methods.

CLASSIFICATION OF IRANIAN NURSES ACCORDING TO THEIR MENTAL HEALTH OUTCOMES USING GHQ-12 QUESTIONNAIRE: A COMPARISON BETWEEN LATENT CLASS ANALYSIS AND K-MEANS CLUSTERING WITH TRADITIONAL SCORING METHOD

PubMed Central

Jamali, Jamshid; Ayatollahi, Seyyed Mohammad Taghi

2015-01-01

Background: Nurses constitute the most providers of health care systems. Their mental health can affect the quality of services and patients’ satisfaction. General Health Questionnaire (GHQ-12) is a general screening tool used to detect mental disorders. Scoring method and determining thresholds for this questionnaire are debatable and the cut-off points can vary from sample to sample. This study was conducted to estimate the prevalence of mental disorders among Iranian nurses using GHQ-12 and also compare Latent Class Analysis (LCA) and K-means clustering with traditional scoring method. Methodology: A cross-sectional study was carried out in Fars and Bushehr provinces of southern Iran in 2014. Participants were 771 Iranian nurses, who filled out the GHQ-12 questionnaire. Traditional scoring method, LCA and K-means were used to estimate the prevalence of mental disorder among Iranian nurses. Cohen’s kappa statistic was applied to assess the agreement between the LCA and K-means with traditional scoring method of GHQ-12. Results: The nurses with mental disorder by scoring method, LCA and K-mean were 36.3% (n=280), 32.2% (n=248), and 26.5% (n=204), respectively. LCA and logistic regression revealed that the prevalence of mental disorder in females was significantly higher than males. Conclusion: Mental disorder in nurses was in a medium level compared to other people living in Iran. There was a little difference between prevalence of mental disorder estimated by scoring method, K-means and LCA. According to the advantages of LCA than K-means and different results in scoring method, we suggest LCA for classification of Iranian nurses according to their mental health outcomes using GHQ-12 questionnaire PMID:26622202

CLASSIFICATION OF IRANIAN NURSES ACCORDING TO THEIR MENTAL HEALTH OUTCOMES USING GHQ-12 QUESTIONNAIRE: A COMPARISON BETWEEN LATENT CLASS ANALYSIS AND K-MEANS CLUSTERING WITH TRADITIONAL SCORING METHOD.

PubMed

Jamali, Jamshid; Ayatollahi, Seyyed Mohammad Taghi

2015-10-01

Nurses constitute the most providers of health care systems. Their mental health can affect the quality of services and patients' satisfaction. General Health Questionnaire (GHQ-12) is a general screening tool used to detect mental disorders. Scoring method and determining thresholds for this questionnaire are debatable and the cut-off points can vary from sample to sample. This study was conducted to estimate the prevalence of mental disorders among Iranian nurses using GHQ-12 and also compare Latent Class Analysis (LCA) and K-means clustering with traditional scoring method. A cross-sectional study was carried out in Fars and Bushehr provinces of southern Iran in 2014. Participants were 771 Iranian nurses, who filled out the GHQ-12 questionnaire. Traditional scoring method, LCA and K-means were used to estimate the prevalence of mental disorder among Iranian nurses. Cohen's kappa statistic was applied to assess the agreement between the LCA and K-means with traditional scoring method of GHQ-12. The nurses with mental disorder by scoring method, LCA and K-mean were 36.3% (n=280), 32.2% (n=248), and 26.5% (n=204), respectively. LCA and logistic regression revealed that the prevalence of mental disorder in females was significantly higher than males. Mental disorder in nurses was in a medium level compared to other people living in Iran. There was a little difference between prevalence of mental disorder estimated by scoring method, K-means and LCA. According to the advantages of LCA than K-means and different results in scoring method, we suggest LCA for classification of Iranian nurses according to their mental health outcomes using GHQ-12 questionnaire.

Latent class analysis reveals clinically relevant atopy phenotypes in 2 birth cohorts.

PubMed

Hose, Alexander J; Depner, Martin; Illi, Sabina; Lau, Susanne; Keil, Thomas; Wahn, Ulrich; Fuchs, Oliver; Pfefferle, Petra Ina; Schmaußer-Hechfellner, Elisabeth; Genuneit, Jon; Lauener, Roger; Karvonen, Anne M; Roduit, Caroline; Dalphin, Jean-Charles; Riedler, Josef; Pekkanen, Juha; von Mutius, Erika; Ege, Markus J

2017-06-01

Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear. We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE). Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort. The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-γ ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk. LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Applying Latent Class Analysis to Risk Stratification for Perioperative Mortality in Patients Undergoing Intraabdominal General Surgery.

PubMed

Kim, Minjae; Wall, Melanie M; Li, Guohua

2016-07-01

Perioperative risk stratification is often performed using individual risk factors without consideration of the syndemic of these risk factors. We used latent class analysis (LCA) to identify the classes of comorbidities and risk factors associated with perioperative mortality in patients presenting for intraabdominal general surgery. The 2005 to 2010 American College of Surgeons National Surgical Quality Improvement Program was used to obtain a cohort of patients undergoing intraabdominal general surgery. Risk factors and comorbidities were entered into LCA models to identify the latent classes, and individuals were assigned to a class based on the highest posterior probability of class membership. Relative risk regression was used to determine the associations between the latent classes and 30-day mortality, with adjustments for procedure. A 9-class model was fit using LCA on 466,177 observations. After combining classes with similar adjusted mortality risks, 5 risk classes were obtained. Compared with the class with average mortality risk (class 4), the risk ratios (95% confidence interval) ranged from 0.020 (0.014-0.027) in the lowest risk class (class 1) to 6.75 (6.46-7.02) in the highest risk class. After adjusting for procedure and ASA physical status, the latent classes remained significantly associated with 30-day mortality. The addition of the risk class variable to a model containing ASA physical status and surgical procedure demonstrated a significant increase in the area under the receiver operator characteristic curve (0.892 vs 0.915; P < 0.0001). Latent classes of risk factors and comorbidities in patients undergoing intraabdominal surgery are predictive of 30-day mortality independent of the ASA physical status and improve risk prediction with the ASA physical status.

Stability of ARDS subphenotypes over time in two randomised controlled trials.

PubMed

Delucchi, Kevin; Famous, Katie R; Ware, Lorraine B; Parsons, Polly E; Thompson, B Taylor; Calfee, Carolyn S

2018-05-01

Two distinct acute respiratory distress syndrome (ARDS) subphenotypes have been identified using data obtained at time of enrolment in clinical trials; it remains unknown if these subphenotypes are durable over time. To determine the stability of ARDS subphenotypes over time. Secondary analysis of data from two randomised controlled trials in ARDS, the ARMA trial of lung protective ventilation (n=473; patients randomised to low tidal volumes only) and the ALVEOLI trial of low versus high positive end-expiratory pressure (n=549). Latent class analysis (LCA) and latent transition analysis (LTA) were applied to data from day 0 and day 3, independent of clinical outcomes. In ALVEOLI, LCA indicated strong evidence of two ARDS latent classes at days 0 and 3; in ARMA, evidence of two classes was stronger at day 0 than at day 3. The clinical and biological features of these two classes were similar to those in our prior work and were largely stable over time, though class 2 demonstrated evidence of progressive organ failures by day 3, compared with class 1. In both LCA and LTA models, the majority of patients (>94%) stayed in the same class from day 0 to day 3. Clinical outcomes were statistically significantly worse in class 2 than class 1 and were more strongly associated with day 3 class assignment. ARDS subphenotypes are largely stable over the first 3 days of enrolment in two ARDS Network trials, suggesting that subphenotype identification may be feasible in the context of clinical trials. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Substance use predictors of victimization profiles among homeless youth: a latent class analysis.

PubMed

Bender, Kimberly; Thompson, Sanna; Ferguson, Kristin; Langenderfer, Lisa

2014-02-01

Although a substantial body of literature demonstrates high prevalence of street victimization among homeless youth, few studies have investigated the existence of victimization classes that differ on the type and frequency of victimization experienced. Nor do we know how substance use patterns relate to victimization classes. Using latent class analysis (LCA), we examined the existence of victimization classes of homeless youth and investigated substance use predictors of class membership utilizing a large purposive sample (N=601) recruited from homeless youth-serving host agencies in three disparate regions of the U.S. Results of the LCA suggest the presence of three distinct victimization profiles - youth fit into a low-victimization class, a witness class, or a high-victimization class. These three victimization classes demonstrated differences in their substance use, including rates of substance abuse/dependence on alcohol and/or drugs. The presence of distinct victimization profiles suggests the need for screening and referral for differential services. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Coping styles of adolescents experiencing multiple forms of discrimination and bullying: evidence from a sample of ethnically diverse urban youth.

PubMed

Garnett, Bernice R; Masyn, Katherine E; Austin, S Bryn; Williams, David R; Viswanath, Kasisomayajula

2015-02-01

We used a latent class analysis (LCA) to characterize coping styles of urban youth and examined if coping styles moderated the association between experiencing discrimination and bullying and depressive symptoms. The data come from the 2006 Boston Youth Survey, where students were asked to select 2 behaviors they do most often when they are upset, from a list of 15 options. A total of 927 (75%) students contributed to the LCA analytic sample (44% non-Hispanic Blacks, 29% Hispanics, and 58% girls). Relative and absolute fit indices determined the number of classes. An interaction term between types of discrimination and bullying experienced and coping style tested for moderation. The LCA revealed that a 3-class solution had the best fit (Lo-Mendell-Rubin likelihood ratio test, 4-class vs 3-class, p-value .12). The largest coping style class was characterized by high endorsement of distractive coping strategies (59%), the second class was characterized by using supportive coping strategies (27%), and the third class was characterized by using avoidance coping strategies (12%). We found a significant interaction between discrimination and coping style for depressive symptoms. The relationship between experiencing discrimination and depression varied based on coping style and the type of discrimination and bullying experienced. © 2015, American School Health Association.

Using Latent Class Analysis to Identify Academic and Behavioral Risk Status in Elementary Students

ERIC Educational Resources Information Center

King, Kathleen R.; Lembke, Erica S.; Reinke, Wendy M.

2016-01-01

Identifying classes of children on the basis of academic and behavior risk may have important implications for the allocation of intervention resources within Response to Intervention (RTI) and Multi-Tiered System of Support (MTSS) models. Latent class analysis (LCA) was conducted with a sample of 517 third grade students. Fall screening scores in…

Comparing the Performance of Improved Classify-Analyze Approaches For Distal Outcomes in Latent Profile Analysis

PubMed Central

Dziak, John J.; Bray, Bethany C.; Zhang, Jieting; Zhang, Minqiang; Lanza, Stephanie T.

2016-01-01

Several approaches are available for estimating the relationship of latent class membership to distal outcomes in latent profile analysis (LPA). A three-step approach is commonly used, but has problems with estimation bias and confidence interval coverage. Proposed improvements include the correction method of Bolck, Croon, and Hagenaars (BCH; 2004), Vermunt’s (2010) maximum likelihood (ML) approach, and the inclusive three-step approach of Bray, Lanza, & Tan (2015). These methods have been studied in the related case of latent class analysis (LCA) with categorical indicators, but not as well studied for LPA with continuous indicators. We investigated the performance of these approaches in LPA with normally distributed indicators, under different conditions of distal outcome distribution, class measurement quality, relative latent class size, and strength of association between latent class and the distal outcome. The modified BCH implemented in Latent GOLD had excellent performance. The maximum likelihood and inclusive approaches were not robust to violations of distributional assumptions. These findings broadly agree with and extend the results presented by Bakk and Vermunt (2016) in the context of LCA with categorical indicators. PMID:28630602

Prevalence Estimation and Validation of New Instruments in Psychiatric Research: An Application of Latent Class Analysis and Sensitivity Analysis

ERIC Educational Resources Information Center

Pence, Brian Wells; Miller, William C.; Gaynes, Bradley N.

2009-01-01

Prevalence and validation studies rely on imperfect reference standard (RS) diagnostic instruments that can bias prevalence and test characteristic estimates. The authors illustrate 2 methods to account for RS misclassification. Latent class analysis (LCA) combines information from multiple imperfect measures of an unmeasurable latent condition to…

Is there Complex Trauma Experience typology for Australian's experiencing extreme social disadvantage and low housing stability?

PubMed

Keane, Carol A; Magee, Christopher A; Kelly, Peter J

2016-11-01

Traumatic childhood experiences predict many adverse outcomes in adulthood including Complex-PTSD. Understanding complex trauma within socially disadvantaged populations has important implications for policy development and intervention implementation. This paper examined the nature of complex trauma experienced by disadvantaged individuals using a latent class analysis (LCA) approach. Data were collected through the large-scale Journeys Home Study (N=1682), utilising a representative sample of individuals experiencing low housing stability. Data on adverse childhood experiences, adulthood interpersonal trauma and relevant covariates were collected through interviews at baseline (Wave 1). Latent class analysis (LCA) was conducted to identify distinct classes of childhood trauma history, which included physical assault, neglect, and sexual abuse. Multinomial logistic regression investigated childhood relevant factors associated with class membership such as biological relationship of primary carer at age 14 years and number of times in foster care. Of the total sample (N=1682), 99% reported traumatic adverse childhood experiences. The most common included witnessing of violence, threat/experience of physical abuse, and sexual assault. LCA identified six distinct childhood trauma history classes including high violence and multiple traumas. Significant covariate differences between classes included: gender, biological relationship of primary carer at age 14 years, and time in foster care. Identification of six distinct childhood trauma history profiles suggests there might be unique treatment implications for individuals living in extreme social disadvantage. Further research is required to examine the relationship between these classes of experience, consequent impact on adulthood engagement, and future transitions though homelessness. Copyright © 2016 Elsevier Ltd. All rights reserved.

Latent Class Analysis of Conduct Problems of Elementary Students Receiving Special Education Services

ERIC Educational Resources Information Center

Toupin, Jean; Déry, Michèle; Verlaan, Pierrette; Lemelin, Jean-Pascal; Lecocq, Aurélie; Jagiellowicz, Jadwiga

2016-01-01

Students with conduct problems (CPs) may present heterogeneity in terms of behavioral manifestations and service needs. Previous studies using Latent Class Analysis (LCA) to capture this heterogeneity have been conducted mostly with community samples and have often applied a narrow definition of CP. Considering this context, this study…

Latent transition analysis of pre-service teachers' efficacy in mathematics and science

NASA Astrophysics Data System (ADS)

Ward, Elizabeth Kennedy

This study modeled changes in pre-service teacher efficacy in mathematics and science over the course of the final year of teacher preparation using latent transition analysis (LTA), a longitudinal form of analysis that builds on two modeling traditions (latent class analysis (LCA) and auto-regressive modeling). Data were collected using the STEBI-B, MTEBI-r, and the ABNTMS instruments. The findings suggest that LTA is a viable technique for use in teacher efficacy research. Teacher efficacy is modeled as a construct with two dimensions: personal teaching efficacy (PTE) and outcome expectancy (OE). Findings suggest that the mathematics and science teaching efficacy (PTE) of pre-service teachers is a multi-class phenomena. The analyses revealed a four-class model of PTE at the beginning and end of the final year of teacher training. Results indicate that when pre-service teachers transition between classes, they tend to move from a lower efficacy class into a higher efficacy class. In addition, the findings suggest that time-varying variables (attitudes and beliefs) and time-invariant variables (previous coursework, previous experiences, and teacher perceptions) are statistically significant predictors of efficacy class membership. Further, analyses suggest that the measures used to assess outcome expectancy are not suitable for LCA and LTA procedures.

Profiles of Community Violence Exposure Among African American Youth: An Examination of Desensitization to Violence Using Latent Class Analysis.

PubMed

Gaylord-Harden, Noni K; Dickson, Daniel; Pierre, Cynthia

2016-07-01

The current study employed latent class analysis (LCA) to identify distinct profiles of community violence exposure and their associations to desensitization outcomes in 241 African American early adolescents (M age = 12.86, SD = 1.28) in the sixth through eighth grade from under-resourced urban communities. Participants self-reported on their exposure to community violence, as well as on depressive and anxiety symptoms. The LCA revealed three distinct classes: a class exposed to low levels of violence (low exposure class), a class exposed to moderately high levels of victimization (victimization class), and a class exposed to high levels of all types of violence (high exposure class). Consistent with predictions, the high exposure class showed the lowest levels of depressive symptoms, suggesting a desensitization outcome. Gender and age were also examined in relation to the classes, and age was significantly associated with an increased risk of being a member of the high exposure class relative to the low exposure class. Using person-based analyses to examine desensitization outcomes provides useful information for prevention and intervention efforts, as it helps to identify a specific subgroup of youth that may be more likely to show desensitization outcomes in the context of community violence. © The Author(s) 2015.

A Latent Class Analysis of Adolescent Gambling: Application of Resilience Theory

ERIC Educational Resources Information Center

Goldstein, Abby L.; Faulkner, Breanne; Cunningham, Rebecca M.; Zimmerman, Marc A.; Chermack, Stephen; Walton, Maureen A.

2013-01-01

The current study examined the application of resilience theory to adolescent gambling using Latent Class Analysis (LCA) to establish subtypes of adolescent gamblers and to explore risk and promotive factors associated with gambling group membership. Participants were a diverse sample of 249 adolescents ages 14 to 18 (30.1 % female, 59.4 % African…

Classifying Patients with Chronic Pelvic Pain into Levels of Biopsychosocial Dysfunction Using Latent Class Modeling of Patient Reported Outcome Measures

PubMed Central

Fenton, Bradford W.; Grey, Scott F.; Tossone, Krystel; McCarroll, Michele; Von Gruenigen, Vivian E.

2015-01-01

Chronic pelvic pain affects multiple aspects of a patient's physical, social, and emotional functioning. Latent class analysis (LCA) of Patient Reported Outcome Measures Information System (PROMIS) domains has the potential to improve clinical insight into these patients' pain. Based on the 11 PROMIS domains applied to n=613 patients referred for evaluation in a chronic pelvic pain specialty center, exploratory factor analysis (EFA) was used to identify unidimensional superdomains. Latent profile analysis (LPA) was performed to identify the number of homogeneous classes present and to further define the pain classification system. The EFA combined the 11 PROMIS domains into four unidimensional superdomains of biopsychosocial dysfunction: Pain, Negative Affect, Fatigue, and Social Function. Based on multiple fit criteria, a latent class model revealed four distinct classes of CPP: No dysfunction (3.2%); Low Dysfunction (17.8%); Moderate Dysfunction (53.2%); and High Dysfunction (25.8%). This study is the first description of a novel approach to the complex disease process such as chronic pelvic pain and was validated by demographic, medical, and psychosocial variables. In addition to an essentially normal class, three classes of increasing biopsychosocial dysfunction were identified. The LCA approach has the potential for application to other complex multifactorial disease processes. PMID:26355825

Distinct patterns of Internet and smartphone-related problems among adolescents by gender: Latent class analysis.

PubMed

Lee, Seung-Yup; Lee, Donghwan; Nam, Cho Rong; Kim, Da Yea; Park, Sera; Kwon, Jun-Gun; Kweon, Yong-Sil; Lee, Youngjo; Kim, Dai Jin; Choi, Jung-Seok

2018-05-23

Background and objectives The ubiquitous Internet connections by smartphones weakened the traditional boundaries between computers and mobile phones. We sought to explore whether smartphone-related problems differ from those of computer use according to gender using latent class analysis (LCA). Methods After informed consents, 555 Korean middle-school students completed surveys on gaming, Internet use, and smartphone usage patterns. They also completed various psychosocial instruments. LCA was performed for the whole group and by gender. In addition to ANOVA and χ 2 tests, post-hoc tests were conducted to examine differences among the LCA subgroups. Results In the whole group (n = 555), four subtypes were identified: dual-problem users (49.5%), problematic Internet users (7.7%), problematic smartphone users (32.1%), and "healthy" users (10.6%). Dual-problem users scored highest for addictive behaviors and other psychopathologies. The gender-stratified LCA revealed three subtypes for each gender. With dual-problem and healthy subgroup as common, problematic Internet subgroup was classified in the males, whereas problematic smartphone subgroup was classified in the females in the gender-stratified LCA. Thus, distinct patterns were observed according to gender with higher proportion of dual-problem present in males. While gaming was associated with problematic Internet use in males, aggression and impulsivity demonstrated associations with problematic smartphone use in females. Conclusions An increase in the number of digital media-related problems was associated with worse outcomes in various psychosocial scales. Gaming may play a crucial role in males solely displaying Internet-related problems. The heightened impulsivity and aggression seen in our female problematic smartphone users requires further research.

Does highly symptomatic class membership in the acute phase predict highly symptomatic classification in victims 6 months after traumatic exposure?

PubMed

Hansen, Maj; Hyland, Philip; Armour, Cherie

2016-05-01

Recently studies have indicated the existence of both posttraumatic stress disorder (PTSD) and acute stress disorder (ASD) subtypes but no studies have investigated their mutual association. Although ASD may not be a precursor of PTSD per se, there are potential benefits associated with early identification of victims at risk of developing PTSD subtypes. The present study investigates ASD and PTSD subtypes using latent class analysis (LCA) following bank robbery (N=371). Moreover, we assessed if highly symptomatic ASD and selected risk factors increased the probability of highly symptomatic PTSD. The results of LCA revealed a three class solution for ASD and a two class solution for PTSD. Negative cognitions about self (OR=1.08), neuroticism (OR=1.09) and membership of the 'High symptomatic ASD' class (OR=20.41) significantly increased the probability of 'symptomatic PTSD' class membership. Future studies are needed to investigate the existence of ASD and PTSD subtypes and their mutual relationship. Copyright © 2016 Elsevier Ltd. All rights reserved.

Parental attitudes towards measles vaccination in the canton of Aargau, Switzerland: a latent class analysis.

PubMed

Weiss, Carine; Schröpfer, Daniel; Merten, Sonja

2016-08-11

Despite the successes of routine national childhood vaccination programmes, measles remains a public health concern. The purpose of this paper is to investigate how patterns of parental attitudes are linked to the decision-making process for or against MMR vaccination. This exploratory study was designed to identify distinct patterns of attitudes towards or against measles vaccination through Latent Class Analysis (LCA) in a sub-sample of mothers living in the canton of Aargau in Switzerland. Parents of young children below 36 months of age were randomly selected through parents' counsellors' registries. Among other questions, respondents were asked to state their agreement in response to 14 belief statements regarding measles vaccination on a 5-point Likert scale. To identify groups of parents showing distinct patterns of attitudes and beliefs regarding measles vaccination, we used Latent Class Analysis (LCA). The LCA showed three classes of parents with different attitudes and believes towards measles vaccination: The biggest group (class 1) are those having positive attitudes towards immunisation, followed by the second biggest group (class 2) which is characterised by having fearful attitudes and by showing uncertainty about immunisation. The third group (class 3) shows distinct patterns of critical attitudes against immunisation. Within this group over 90 % agree or totally agree that immunisation is an artificial intrusion into the natural immune system and therefore want to vaccinate their children only if necessary. We find that parents in the Canton Aargau who hesitate to vaccinate their children against measles, mumps and rubella show distinct opinions and attitudes. Health professionals should be aware of these perceptions to tailor their messages accordingly and positively influence these parents to vaccinate their children. Special attention needs to be given to those parents who are planning to vaccinate their children but are not following the national guidelines.

Assessing the existence of dissociative PTSD in sub-acute patients of whiplash.

PubMed

Hansen, Maj; Hyland, Philip; Armour, Cherie; Andersen, Tonny E

2018-03-16

Numerous studies investigating dissociative posttraumatic stress disorder (D-PTSD) have emerged. However, there is a lack of studies investigating D-PTSD following a wider range of traumatic exposure. Thus, the present study investigates D-PTSD using latent class analysis (LCA) in sub-acute patients of whiplash and associated risk factors. The results of LCA showed a three-class solution primarily distributed according to posttraumatic stress disorder (PTSD) symptom severity and thus no indication of D-PTSD. Dissociative symptoms, psychological distress (i.e. anxiety/depression), and pain severity significantly predicted PTSD severity. Combined, the results support the component model of dissociation and PTSD, while still stressing the importance of dissociative symptoms when planning treatment for PTSD.

A Comparison of Classification Approaches for Cyberbullying and Traditional Bullying Using Data from Six European Countries

ERIC Educational Resources Information Center

Schultze-Krumbholz, Anja; Göbel, Kristin; Scheithauer, Herbert; Brighi, Antonella; Guarini, Annalisa; Tsorbatzoudis, Haralambos; Barkoukis, Vassilis; Pyzalski, Jacek; Plichta, Piotr; Del Rey, Rosario; Casas, José A.; Thompson, Fran; Smith, Peter K.

2015-01-01

In recently published studies on cyberbullying, students are frequently categorized into distinct (cyber)bully and (cyber)victim clusters based on theoretical assumptions and arbitrary cut-off scores adapted from traditional bullying research. The present study identified involvement classes empirically using latent class analysis (LCA), to…

Validation of Diagnostic Measures Based on Latent Class Analysis: A Step Forward in Response Bias Research

ERIC Educational Resources Information Center

Thomas, Michael L.; Lanyon, Richard I.; Millsap, Roger E.

2009-01-01

The use of criterion group validation is hindered by the difficulty of classifying individuals on latent constructs. Latent class analysis (LCA) is a method that can be used for determining the validity of scales meant to assess latent constructs without such a priori classifications. The authors used this method to examine the ability of the L…

Discrete subgroups of adolescents diagnosed with borderline personality disorder: a latent class analysis of personality features.

PubMed

Ramos, Vera; Canta, Guilherme; de Castro, Filipa; Leal, Isabel

2014-08-01

Research suggests that borderline personality disorder (BPD) can be diagnosed in adolescents and is marked by considerable heterogeneity. This study aimed to identify personality features characterizing adolescents with BPD and possible meaningful patterns of heterogeneity that could lead to personality subgroups. The authors analyzed data on 60 adolescents, ages 15 to 18 years, who met DSM criteria for a BPD diagnosis. The authors used latent class analysis (LCA) to identify subgroups based on the personality pattern scales from the Millon Adolescent Clinical Inventory (MACI). LCA indicated that the best-fitting solution was a two-class model, identifying two discrete subgroups of BPD adolescents that were described as internalizing and externalizing. The subgroups were then compared on clinical and sociodemographic variables, measures of personality dimensions, DSM BPD criteria, and perception of attachment styles. Adolescents with a BPD diagnosis constitute a heterogeneous group and vary meaningfully on personality features that can have clinical implications for treatment.

Subjective reactions to cocaine and marijuana are associated with abuse and dependence.

PubMed

Grant, Julia D; Scherrer, Jeffrey F; Lyons, Michael J; Tsuang, Ming; True, William R; Bucholz, Kathleen K

2005-09-01

Subjective effects of marijuana and cocaine use are associated with amount of drug use and potentially with risk of abuse and dependence. We used Latent Class Analyses (LCA) to examine subjective responses to two categories of drugs and link these to abuse and dependence. In 1992, subjective responses were queried of 2506 marijuana and 661 cocaine lifetime users who were members of the Vietnam Era Twin Registry. LCA was used to identify classes of subjective effects. Multinomial logistic regression models were computed to test for an association between classes and marijuana and cocaine abuse or dependence. The best LCA solution for marijuana identified 6 distinct classes characterized as positive, relaxed, reactive, adverse, low and very reactive. The best LCA solution for cocaine identified 5 distinct classes characterized as positive, alert, adverse, low and very reactive. Marijuana abuse and dependence were significantly associated with each latent class. Cocaine abuse was associated with the reactive class (OR=3.9; 95% CI: 1.6-9.5). Cocaine dependence was associated with reactive (OR=15.3; 95% CI: 7.1-32.6), adverse (OR=9.7; 95% CI: 4.5-21.0) and very reactive (OR=18.7; 95% CI: 5.6-62.6) classes. We found evidence for both qualitative and quantitative subjective effect profiles. Subjective effects, both positive and adverse are associated with lifetime risk for marijuana and cocaine dependence.

Sexual Initiation and Complex Recent Polydrug Use Patterns Among Male Sex Workers in Vietnam: A Preliminary Epidemiological Trajectory.

PubMed

Yu, Gary; Goldsamt, Lloyd A; Clatts, Michael C; Giang, Lê Minh

2016-05-01

Little is known about the age of onset of sexual and drug risk and their association with complex patterns of recent drug use among male sex workers (MSW) in a developing country, such as Vietnam. The aim of this study was to determine whether latent class analysis (LCA) would aid in the detection of current individual and polydrug use combinations to predict how different trajectories of sexual and drug initiation contribute to different patterns of current illicit drug use. Data were collected from a cross-sectional survey administered to young MSWs between 2010 and 2011 in Vietnam (N = 710). LCA clustered participants into recent drug use groups, incorporating both the specific types and overall count of different drugs used. Men reported drug use within a 1 month period from an 11-item drug use list. LCA identified three distinct drug use classes: (1) alcohol use, (2) alcohol and tobacco use, and (3) high polydrug use. The current drug use classes are associated with sex worker status, housing stability, income level, educational attainment, marital status, sexual identity, and sexual preferences. High levels of drug use are strongly associated with being a recent sex worker, not having recent stable housing, higher than median income, more than a high school education, less likely to be currently in school and more likely to have non-homosexual preferences and heterosexual partners. An event history analysis approach (time-event displays) examined the timing of the age of onset of drug and sexual risks. Early ages of drug and sexual initiation are seen for all three classes. High current drug users show earlier onset of these risks, which are significantly delayed for moderate and low current drug users. LCA incorporating an overall count of different drugs detected three distinct current drug use classes. The data illustrates that the complexity of drug factors that must be accounted for, both in advancing our epidemiological understanding of the complexity of drug use and the use of drug and sexual risk initiation data to predict current drug use subtypes among high-risk populations.

The Structure of Student Satisfaction with College Services: A Latent Class Model

ERIC Educational Resources Information Center

Adwere-Boamah, Joseph

2011-01-01

Latent Class Analysis (LCA) was used to identify distinct groups of Community college students based on their self-ratings of satisfaction with student service programs. The programs were counseling, financial aid, health center, student programs and student government. The best fitting model to describe the data was a two Discrete-Factor model…

Patterns of Adolescent Bullying Behaviors: Physical, Verbal, Exclusion, Rumor, and Cyber

ERIC Educational Resources Information Center

Wang, Jing; Iannotti, Ronald J.; Luk, Jeremy W.

2012-01-01

Patterns of engagement in cyber bullying and four types of traditional bullying were examined using latent class analysis (LCA). Demographic differences and externalizing problems were evaluated across latent class membership. Data were obtained from the 2005-2006 Health Behavior in School-aged Survey and the analytic sample included 7,508 U.S.…

Profile of children placed in residential psychiatric program: Association with delinquency, involuntary mental health commitment, and reentry into care.

PubMed

Yampolskaya, Svetlana; Mowery, Debra; Dollard, Norín

2014-05-01

This study examined characteristics and profiles of youth receiving services in 1 of Florida's Medicaid-funded residential mental health treatment programs--State Inpatient Psychiatric Program (SIPP)--between July 1, 2004, and June 30, 2008 (N=1,432). Latent class analysis (LCA) was used to classify youth, and 3 classes were identified: Children With Multiple Needs, Children With No Caregivers, and Abused Children With Substantial Maltreatment History. The results of LCA showed that Children With Multiple Needs experienced the greatest risk for adverse outcomes. Compared with youth in the other 2 classes, these children were more likely to get readmitted to SIPP, more likely to become involved with the juvenile justice system, and more likely to experience involuntary mental health assessments. Implications of the findings are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved

Sexual Behavior Latent Classes Among Men Who Have Sex With Men: Associations With Sexually Transmitted Infections.

PubMed

Rice, Cara E; Norris Turner, Abigail; Lanza, Stephanie T

2017-01-01

Men who have sex with men (MSM) are at disproportionate risk of acquisition of sexually transmitted infections (STIs). We used latent class analysis (LCA) to examine patterns of sexual behavior among MSM and how those patterns are related to STIs. We examined patterns of sexual behavior using behavioral and clinical data from a cross-sectional study of 235 MSM who presented to an urban sexual health clinic for STI testing. Analyzed data were collected using a combination of interviewer- and self-administered surveys and electronic health records. We used LCA to identify underlying subgroups of men based on their sexual behavior, described the demographics of the latent classes, and examined the association between the latent classes and STI status. We identified three latent classes of sexual behavior: Unprotected Anal Intercourse (UAI) Only (67%), Partner Seekers (14%), and Multiple Behaviors (19%). Men in the Multiple Behaviors class had a 67% probability of being STI positive, followed by men in the UAI Only class (27%) and men in the Partner Seekers class (22%). Examining the intersection of a variety of sexual practices indicates particular subgroups of MSM have the highest probability of being STI positive.

Intimate partner violence against low-income women in Mexico City and associations with work-related disruptions: a latent class analysis using cross-sectional data.

PubMed

Gupta, Jhumka; Willie, Tiara C; Harris, Courtney; Campos, Paola Abril; Falb, Kathryn L; Garcia Moreno, Claudia; Diaz Olavarrieta, Claudia; Okechukwu, Cassandra A

2018-03-07

Disrupting women's employment is a strategy that abusive partners could use to prevent women from maintaining economic independence and stability. Yet, few studies have investigated disruptions in employment among victims of intimate partner violence (IPV) in low-income and middle-income countries. Moreover, even fewer have sought to identify which female victims of IPV are most vulnerable to such disruptions. Using baseline data from 947 women in Mexico City enrolled in a randomised controlled trial, multilevel latent class analysis (LCA) was used to classify women based on their reported IPV experiences. Furthermore, multilevel logistic regression analyses were performed on a subsample of women reporting current work (n=572) to investigate associations between LCA membership and IPV-related employment disruptions. Overall, 40.6% of women who were working at the time of the survey reported some form of work-related disruption due to IPV. LCA identified four distinct classes of IPV experiences: Low Physical and Sexual Violence (39.1%); High Sexual and Low Physical Violence class (9.6%); High Physical and Low Sexual Violence and Injuries (36.5%); High Physical and Sexual Violence and Injuries (14.8%). Compared with women in the Low Physical and Sexual Violence class, women in the High Physical and Sexual Violence and Injuries class and women in the High Physical and Low Sexual Violence and Injuries class were at greater risk of work disruption (adjusted relative risk (ARR) 2.44, 95% CI 1.80 to 3.29; ARR 2.05, 95% CI 1.56 to 2.70, respectively). No other statistically significant associations emerged. IPV, and specific patterns of IPV experiences, must be considered both in work settings and, more broadly, by economic development programmes. NCT01661504. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Detained Male Adolescent Offender's Emotional, Physical and Sexual Maltreatment Profiles and Their Associations to Psychiatric Disorders and Criminal Behaviors.

PubMed

Aebi, Marcel; Linhart, Susanne; Thun-Hohenstein, Leonhard; Bessler, Cornelia; Steinhausen, Hans-Christoph; Plattner, Belinda

2015-07-01

The objective of the present study was to analyse patterns of emotional, physical and sexual maltreatment in detained male juvenile offenders using latent class analysis (LCA). The association of maltreatment related LCA profiles with psychopathology and criminal behaviors was also studied. LCA based on the items of the Child Trauma Questionnaire (CTQ) assessing childhood emotional, physical, and sexual abuse was performed in a sample of 260 male adolescent offenders (mean age = 16.5 years, SD = 1.29 years). Chi square tests and general linear models were performed to assess the associations of CTQ profiles with categorical interview-based psychiatric disorders, dimensional Youth Self-Report problem scales, and officially registered offenses. LCA suggested a three class solution: (1) a no/mild trauma (NM; 76 %) (2) emotional and physical trauma (EP; 18 %) and (3) emotional, physical, and sexual trauma (EPS; 8 %). The classes EP and EPS were related to a variety of psychiatric disorders and self-reported mental health problems. Furthermore, EPS showed higher presence of a subsequent re-incarceration compared to NM. A majority of sexually abused juveniles also experienced emotional and physical abuse reflecting gravely disturbed family systems. Multiple abuse in childhood was associated with a broad variety of disorders including externalizing disorders and repeated criminal offending. Such findings indicate that trauma assessment is also relevant in externalizing youth. A comprehensive treatment approach for detained boys with multiple abuse experiences is required targeting both mental health needs and the reduction of criminal behaviors.

Sex-related and non-sex-related comorbidity subtypes of tic disorders: a latent class approach.

PubMed

Rodgers, S; Müller, M; Kawohl, W; Knöpfli, D; Rössler, W; Castelao, E; Preisig, M; Ajdacic-Gross, V

2014-05-01

Recent evidence suggests that there may be more than one Gilles de la Tourette syndrome (GTS)/tic disorder phenotype. However, little is known about the common patterns of these GTS/tic disorder-related comorbidities. In addition, sex-specific phenomenological data of GTS/tic disorder-affected adults are rare. Therefore, this community-based study used latent class analyses (LCA) to investigate sex-related and non-sex-related subtypes of GTS/tic disorders and their most common comorbidities. The data were drawn from the PsyCoLaus study (n = 3691), a population-based survey conducted in Lausanne, Switzerland. LCA were performed on the data of 80 subjects manifesting motor/vocal tics during their childhood/adolescence. Comorbid attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder, depressive, phobia and panic symptoms/syndromes comprised the selected indicators. The resultant classes were characterized by psychosocial correlates. In LCA, four latent classes provided the best fit to the data. We identified two male-related classes. The first class exhibited both ADHD and depression. The second class comprised males with only depression. Class three was a female-related class depicting obsessive thoughts/compulsive acts, phobias and panic attacks. This class manifested high psychosocial impairment. Class four had a balanced sex proportion and comorbid symptoms/syndromes such as phobias and panic attacks. The complementary occurrence of comorbid obsessive thoughts/compulsive acts and ADHD impulsivity was remarkable. To the best of our knowledge, this is the first study applying LCA to community data of GTS symptoms/tic disorder-affected persons. Our findings support the utility of differentiating GTS/tic disorder subphenotypes on the basis of comorbid syndromes. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Obesity and Cigarette Smoking: Extending the Link to E-cigarette/Vaping Use.

PubMed

Lanza, H Isabella; Pittman, Patricia; Batshoun, Jennifer

2017-05-01

In recent years, electronic tobacco (e-cigarette/vaping) use among young adults has grown exponentially. Given past research linking obesity and cigarette smoking, assessing whether this relationship extends to electronic tobacco use is warranted. The current study examined weight status as a correlate of substance use patterns reflecting electronic tobacco use. Survey data were collected from a convenience sample of 452 (59% female) undergraduates attending a large, public university during the 2015-2016 academic year. Latent class analysis (LCA) was conducted to identify substance use classes and examine weight status as a covariate of class membership. LCA analyses identified 4 classes: High Substance Use (19%), Risky Alcohol Use (14%), Cigarette/Electronic Tobacco Use (17%), and Low Substance Use (50%). Both obesity status and greater deviation from one's group body mass index (BMI) norm were associated with a higher likelihood of belonging to the Cigarette/Electronic Tobacco Use class. Findings suggest that electronic tobacco use may fit well into previously established relationships between higher weight status and tobacco use. Future research should examine the longitudinal processes and pathways underlying the relationship between weight status and electronic tobacco use.

Latent Transition Analysis of Pre-Service Teachers' Efficacy in Mathematics and Science

ERIC Educational Resources Information Center

Ward, Elizabeth Kennedy

2009-01-01

This study modeled changes in pre-service teacher efficacy in mathematics and science over the course of the final year of teacher preparation using latent transition analysis (LTA), a longitudinal form of analysis that builds on two modeling traditions (latent class analysis (LCA) and auto-regressive modeling). Data were collected using the…

Examining the Stability of "DSM-IV" and Empirically Derived Eating Disorder Classification: Implications for "DSM-5"

ERIC Educational Resources Information Center

Peterson, Carol B.; Crow, Scott J.; Swanson, Sonja A.; Crosby, Ross D.; Wonderlich, Stephen A.; Mitchell, James E.; Agras, W. Stewart; Halmi, Katherine A.

2011-01-01

Objective: The purpose of this investigation was to derive an empirical classification of eating disorder symptoms in a heterogeneous eating disorder sample using latent class analysis (LCA) and to examine the longitudinal stability of these latent classes (LCs) and the stability of DSM-IV eating disorder (ED) diagnoses. Method: A total of 429…

A social network-informed latent class analysis of patterns of substance use, sexual behavior, and mental health: Social Network Study III, Winnipeg, Manitoba, Canada.

PubMed

Hopfer, Suellen; Tan, Xianming; Wylie, John L

2014-05-01

We assessed whether a meaningful set of latent risk profiles could be identified in an inner-city population through individual and network characteristics of substance use, sexual behaviors, and mental health status. Data came from 600 participants in Social Network Study III, conducted in 2009 in Winnipeg, Manitoba, Canada. We used latent class analysis (LCA) to identify risk profiles and, with covariates, to identify predictors of class. A 4-class model of risk profiles fit the data best: (1) solitary users reported polydrug use at the individual level, but low probabilities of substance use or concurrent sexual partners with network members; (2) social-all-substance users reported polydrug use at the individual and network levels; (3) social-noninjection drug users reported less likelihood of injection drug and solvent use; (4) low-risk users reported low probabilities across substances. Unstable housing, preadolescent substance use, age, and hepatitis C status predicted risk profiles. Incorporation of social network variables into LCA can distinguish important subgroups with varying patterns of risk behaviors that can lead to sexually transmitted and bloodborne infections.

Child abuse and neglect profiles and their psychosocial consequences in a large sample of incarcerated males.

PubMed

Debowska, Agata; Boduszek, Daniel

2017-03-01

Research examining child abuse and neglect (CAN) profiles among adult offender populations is lacking. Therefore, the primary aim of the present study was to address this limitation by using latent class analysis (LCA) to identify meaningful classes of individuals who have experienced physical abuse, emotional abuse, sexual abuse, as well as neglect. Another aim was to estimate the association between CAN class membership and external criteria (psychopathy factors, self-esteem, attitudes towards male sexual violence in dating relationships, child sexual abuse myth acceptance, violent offending, and age). Data were collected among a large systematically selected sample of adult male inmates (N=1261). Based on LCA, three unique classes of CAN were distinguished, including a 'low abuse' group (43.4% of the sample), a 'high physical and emotional abuse' group (51.3%), and a 'poly-victimized' group (5.3%). The analysis revealed that the CAN classes were differentially associated with affective responsiveness, cognitive responsiveness, personal self-esteem, prison self-esteem, attitudes towards male sexual violence in dating relationships, and violent offending. Findings highlight the unique nature of CAN constellations among criminal justice involved participants. The significance of the present results is discussed in relation to past and future research. Potential contributions to treatment strategies are also presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Variety of Ecstasy/MDMA Users: Results from the National Epidemiologic Survey on Alcohol and Related Conditions

PubMed Central

Wu, Li-Tzy; Parrott, Andy C.; Ringwalt, Christopher L.; Yang, Chongming; Blazer, Dan G.

2011-01-01

This study investigates the potential heterogeneity of ecstasy or MDMA (3,4-methylenedioxy-N-methylamphetamine) users. Data came from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Latent class analysis (LCA) and multinomial logistic regression procedures were used to identify subtypes of ecstasy users. Approximately 1.6% (n=562) of adult participants (N=43,093) reported lifetime ecstasy use. LCA identified three subtypes of ecstasy users. Class 1 exhibited pervasive use of most drug classes (ecstasy–polydrug users, 37%). Class 2 reported a high rate of use of marijuana and cocaine and a moderate use of amphetamines (ecstasy–marijuana–stimulant users, 29%). Class 3 was characterized by a high rate of use of marijuana and a low use of primarily prescription-type drugs (ecstasy– marijuana users, 34%). Subtypes were distinguished by family income, history of substance abuse treatment, and familial substance abuse. Class 1 exhibited the highest prevalence of disorders related to the use of marijuana (77%), tobacco (66%), amphetamines (36%), opioids (35%), sedatives (31%), and tranquilizers (30%). The recent resurgence in ecstasy use among adults underscores the need to monitor trends in its use. PMID:19874166

A Latent Class Analysis of Early Adolescent Peer and Dating Violence: Associations With Symptoms of Depression and Anxiety.

PubMed

Garthe, Rachel C; Sullivan, Terri N; Behrhorst, Kathryn L

2018-02-01

Violence within peer and dating contexts is prevalent among early adolescents. Youth may be victims and/or aggressors and be involved in violence across multiple contexts, resulting in negative outcomes. This study identified patterns of perpetration and victimization for peer and dating violence, using a latent class analysis (LCA), and examined how different patterns of engaging in or experiencing violence among early adolescents were associated with symptoms of depression and anxiety. Participants included a sample of 508 racially and ethnically diverse youth (51% male) who had dated in the past 3 months. Youth were in the seventh grade within 37 schools and were primarily from economically disadvantaged communities across four sites in the United States. LCA identified three classes: (a) a low involvement in violence class, (b) a peer aggression and peer victimization class, and (c) a peer and dating violence class. Youth involved with multiple forms of violence displayed significantly higher levels of depressive and anxious symptoms than those with low involvement in violence. Study findings revealed the importance of understanding how peer and dating violence co-occur, and how different patterns of aggression and victimization were related to internalizing symptoms. Prevention efforts should address the intersection of victimization and perpetration in peer and dating contexts in potentially reducing internalizing symptoms among early adolescents.

The Lay Public's Understanding and Perception of Dementia in a Developed Asian Nation

PubMed Central

Tan, Wai Jia; Hong, Song-Iee; Luo, Nan; Lo, Tong Jen; Yap, Philip

2012-01-01

Background Early detection of dementia aims to improve treatment outcomes. However, poor perception and understanding of dementia are significant barriers. We aim to investigate the public's perception of dementia and identify variables associated with the different profiles of public perception. Methods A custom-designed questionnaire was used to assess laypersons’ knowledge and perception of dementia during a health fair at a public hospital in Singapore, a developed Asian nation. Out of a sample of 370 subjects, 32 declined to participate (response rate = 91.4%). Latent class analysis (LCA) was used to identify meaningful subgroups of subjects from significant associations with multiple indicators of dementia awareness. Multinomial logistic regression was performed exploring variables associated with each of the subgroups derived from LCA. Results The majority of the study participants were female (66.9%), 65 years or older (71.1%), and ethnic Chinese (88.1%). LCA classified the study participants into 3 subgroups: Class 1 (good knowledge, good attitude), Class 2 (good knowledge, poor attitude), and Class 3 (poor knowledge, poor attitude), in proportions of 14.28, 63.83, and 21.88%, respectively. Compared to other classes, participants with good knowledge and good attitude towards dementia (Class 1) were more likely to know someone with dementia and understand the effects of the disease, be married, live in private housing, receive higher monthly income, and not profess belief in Buddhism, Taoism, or Hinduism. Conclusion Our results show that the public in Singapore may not be ready for screening initiatives and early dementia diagnosis. Education efforts should be targeted at lower socioeconomic groups, singles, and those of certain oriental religions. PMID:23139688

Two distinct phenotypes of asthma in elite athletes identified by latent class analysis.

PubMed

Couto, Mariana; Stang, Julie; Horta, Luís; Stensrud, Trine; Severo, Milton; Mowinckel, Petter; Silva, Diana; Delgado, Luís; Moreira, André; Carlsen, Kai-Håkon

2015-01-01

Clusters of asthma in athletes have been insufficiently studied. Therefore, the present study aimed to characterize asthma phenotypes in elite athletes using latent class analysis (LCA) and to evaluate its association with the type of sport practiced. In the present cross-sectional study, an analysis of athletes' records was carried out in databases of the Portuguese National Anti-Doping Committee and the Norwegian School of Sport Sciences. Athletes with asthma, diagnosed according to criteria given by the International Olympic Committee, were included for LCA. Sports practiced were categorized into water, winter and other sports. Of 324 files screened, 150 files belonged to asthmatic athletes (91 Portuguese; 59 Norwegian). LCA retrieved two clusters: "atopic asthma" defined by allergic sensitization, rhinitis and allergic co-morbidities and increased exhaled nitric oxide levels; and "sports asthma", defined by exercise-induced respiratory symptoms and airway hyperesponsiveness without allergic features. The risk of developing the phenotype "sports asthma" was significantly increased in athletes practicing water (OR = 2.87; 95% CI [1.82-4.51]) and winter (OR = 8.65; 95% CI [2.67-28.03]) sports, when compared with other athletes. Two asthma phenotypes were identified in elite athletes: "atopic asthma" and "sports asthma". The type of sport practiced was associated with different phenotypes: water and winter sport athletes had three- and ninefold increased risk of "sports asthma". Recognizing different phenotypes is clinically relevant as it would lead to distinct targeted treatments.

Obesity and Cigarette Smoking: Extending the Link to E cigarette/Vaping Use

PubMed Central

Lanza, H. Isabella; Pittman, Patricia; Batshoun, Jennifer

2017-01-01

Objectives In recent years, electronic tobacco (e-cigarette/vaping) use among young adults has grown exponentially. Given past research linking obesity and cigarette smoking, assessing whether this relationship extends to electronic tobacco use is warranted. The current study examined weight status as a correlate of substance use patterns reflecting electronic tobacco use. Methods Survey data were collected from a convenience sample of 452 (59% female) undergraduates attending a large, public university during the 2015–2016 academic year. Latent class analysis (LCA) was conducted to identify substance use classes and examine weight status as a covariate of class membership. Results LCA analyses identified 4 classes: High Substance Use (19%), Risky Alcohol Use (14%), Cigarette/Electronic Tobacco Use (17%), and Low Substance Use (50%). Both obesity status and greater deviation from one’s group body mass index (BMI) norm were associated with a higher likelihood of belonging to the Cigarette/Electronic Tobacco Use class. Conclusions Findings suggest that electronic tobacco use may fit well into previously established relationships between higher weight status and tobacco use. Future research should examine the longitudinal processes and pathways underlying the relationship between weight status and electronic tobacco use. PMID:28376978

Assessing operating characteristics of CAD algorithms in the absence of a gold standard

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

Roy Choudhury, Kingshuk; Paik, David S.; Yi, Chin A.

2010-04-15

Purpose: The authors examine potential bias when using a reference reader panel as ''gold standard'' for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. Methods: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range ofmore » operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. Results: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value <0.0001) than LCA (ARB -2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). Conclusions: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.« less

Translating an AI application from Lisp to Ada: A case study

NASA Technical Reports Server (NTRS)

Davis, Gloria J.

1991-01-01

A set of benchmarks was developed to test the performance of a newly designed computer executing both Lisp and Ada. Among these was AutoClassII -- a large Artificial Intelligence (AI) application written in Common Lisp. The extraction of a representative subset of this complex application was aided by a Lisp Code Analyzer (LCA). The LCA enabled rapid analysis of the code, putting it in a concise and functionally readable form. An equivalent benchmark was created in Ada through manual translation of the Lisp version. A comparison of the execution results of both programs across a variety of compiler-machine combinations indicate that line-by-line translation coupled with analysis of the initial code can produce relatively efficient and reusable target code.

Comparison of two methods for composite score generation in dry eye syndrome.

PubMed

See, Craig; Bilonick, Richard A; Feuer, William; Galor, Anat

2013-09-19

To compare two methods of composite score generation in dry eye syndrome (DES). Male patients seen in the Miami Veterans Affairs eye clinic with normal eyelid, corneal, and conjunctival anatomy were recruited to participate in the study. Patients filled out the Dry Eye Questionnaire 5 (DEQ5) and underwent measurement of tear film parameters. DES severity scores were generated by independent component analysis (ICA) and latent class analysis (LCA). A total of 247 men were included in the study. Mean age was 69 years (SD 9). Using ICA analysis, osmolarity was found to carry the largest weight, followed by eyelid vascularity and meibomian orifice plugging. Conjunctival injection and tear breakup time (TBUT) carried the lowest weights. Using LCA analysis, TBUT was found to be best at discriminating healthy from diseased eyes, followed closely by Schirmer's test. DEQ5, eyelid vascularity, and conjunctival injection were the poorest at discrimination. The adjusted correlation coefficient between the two generated composite scores was 0.63, indicating that the shared variance was less than 40%. Both ICA and LCA produced composite scores for dry eye severity, with weak to moderate agreement; however, agreement for the relative importance of single diagnostic tests was poor between the two methods.

Exploring gender differences in the patterns of intimate partner violence in Canada: a latent class approach.

PubMed

Ansara, Donna L; Hindin, Michelle J

2010-10-01

There has been an ongoing debate about the extent and nature of gender differences in the experience of intimate partner violence (IPV). Disagreement about the appropriate definition of IPV is central to this debate. This study used latent class analysis (LCA) to map the patterns of physical violence, sexual coercion, psychological abuse and controlling behaviour, and examined whether LCA can better illuminate the gendered nature of this experience than conventional measures of IPV. Data from the 2004 Canadian General Social Survey were analysed, which included 8360 women and 7056 men 15 years of age and over who reported a current or ex-spouse or common-law partner. Results revealed more variation in the patterns of IPV for women than for men. Six classes were found for women, whereas four classes were found for men. Women and men were equally likely to experience less severe acts of physical aggression that were not embedded in a pattern of control. However, only women experienced a severe and chronic pattern of violence and control involving high levels of fear and injury. For women and men, intermediate patterns of violence and control, and patterns describing exclusively non-physical acts of abuse were also found. The results also revealed substantial differences in the IPV subtypes for those reporting about a current versus an ex-partner. These results support the use of LCA in identifying meaningful patterns of IPV and provide a more nuanced understanding of the role of gender than conventional measures. Implications for sampling within IPV research are discussed.

Personality and changes in comorbidity patterns among anxiety and depressive disorders.

PubMed

Spinhoven, Philip; de Rooij, Mark; Heiser, Willem; Smit, Jan H; Penninx, Brenda W J H

2012-11-01

This prospective study examined the prognostic value of the Big Five personality model for changes in comorbidity patterns of emotional disorders both from a person- and trait-centered perspective. Moreover, it is investigated whether the predictive effect of personality can be attributed to symptom severity at baseline. We followed a cohort of 2566 persons (18-65 years) recruited in primary and specialized mental health care during two years. Personality dimensions at baseline were assessed with the NEO-FFI. The Diagnostic and Statistical Manual of Mental Disorders (4th ed.)-based diagnostic interviews with the CIDI allowed assessment of changes in comorbidity patterns of anxiety and depressive disorders over two years. Data were analyzed with latent class analysis (LCA) and latent transition analysis (LTA). LCA identified a four-class latent comorbidity class solution (Few Disorders, Fear Disorders, Distress Disorders, and Comorbid Fear and Distress Disorders) and a five-class latent personality class solution (High Resilients, Medium Resilients, Low Overcontrollers, Medium Overcontrollers, and High Overcontrollers). LTA showed that the likelihood of remaining in the same latent class was larger than that of transitioning to a less severe comorbidity class. Also, after correcting for symptom severity, medium and high Overcontrollers as well as participants with lower levels of conscientiousness were less likely to transition to a less severe comorbidity class. In particular, the individual trait of conscientiousness may be less dependent on current levels of anxiety and depressive symptoms and be a key pathoplastic or even predisposing variable in anxiety and depression and needs more theoretical and empirical study. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

Development of two socioeconomic indices for Saudi Arabia.

PubMed

AlOmar, Reem S; Parslow, Roger C; Law, Graham R

2018-06-26

Health and socioeconomic status (SES) are linked in studies worldwide. Measures of SES exist for many countries, however not for Saudi Arabia (SA). We describe two indices of area-based SES for SA. Routine census data has been used to construct two indices of SES at the geographically-delimited administrative region of Governorates in SA (n = 118). The data used included indicators of educational status, employment status, car and material ownership. A continuous measure of SES was constructed using exploratory factor analysis (EFA) and a categorical measure of SES using latent class analysis (LCA). Both indices were mapped by Governorates. The EFA identified three factors: The first explained 51.58% of the common variance within the interrelated factors, the second 15.14%, and the third 14.26%. These proportions were used in the formulation of the standard index. The scores were fixed to range from 100 for the affluent Governorate and 0 for the deprived. The LCA found a 4 class model as the best model fit. Class 1 was termed "affluent" and included 11.01% of Governorates, class 2 "upper middle class" (44.91%), class 3 "lower middle class" (33.05%) and class 4 "deprived" (11.01%). The populated urbanised Governorates were found to be the most affluent whereas the smaller rural Governorates were the most deprived. This is the first description of measures of SES in SA at a geographical level. Two measures have been successfully constructed and mapped. The maps show similar patterns suggesting validity. Both indices support the common perception of SES in SA.

Configurations of Common Childhood Psychosocial Risk Factors

ERIC Educational Resources Information Center

Copeland, William; Shanahan, Lilly; Costello, E. Jane; Angold, Adrian

2009-01-01

Background: Co-occurrence of psychosocial risk factors is commonplace, but little is known about psychiatrically-predictive configurations of psychosocial risk factors. Methods: Latent class analysis (LCA) was applied to 17 putative psychosocial risk factors in a representative population sample of 920 children ages 9 to 17. The resultant class…

Patterns of Drug Use and Serum Sodium Concentrations in Older Hospitalized Patients: A Latent Class Analysis Approach.

PubMed

Woodman, Richard J; Wood, Karen M; Kunnel, Aline; Dedigama, Maneesha; Pegoli, Matthew A; Soiza, Roy L; Mangoni, Arduino A

2016-12-01

Several drugs may lower serum sodium concentrations (NaC) in older patients. However, distinguishing their individual effects is particularly difficult in this population because of the high prevalence of polypharmacy and disease states that are per se associated with hyponatremia. Our objective was to identify specific patterns of medication use in older hospitalized patients and determine whether these patterns were associated with serum NaC. We collected clinical and demographic data, pre-admission drugs, Drug Burden Index (DBI) score, and average NaC during hospitalization in a consecutive series of older medical patients (n = 101, mean ± standard deviation [SD] age 87 ± 6 years). We used latent class analysis (LCA) to identify specific patterns of drug use and multivariate regression to determine the associations between 14 separate drug classes, identified patterns of drug use, and NaC. LCA revealed three patterns: lower overall drug use (class 1), anticoagulant use and higher drug use (class 2), and antiplatelet use (class 3). Mean (±SD) DBI score in each class was 2.7 ± 1.3, 3.3 ± 1.6, and 2.4 ± 1.5, respectively (p = 0.04). Mean (± SD) NaC in classes 1, 2, and 3 were 140.6 ± 6.8, 138.7 ± 5.3, and 136.5 ± 4.7 mmol/l, respectively (p = 0.006). After adjustment for age, sex, Charlson Comorbidity Index score, estimated glomerular filtration rate (eGFR), DBI score, and digoxin use, mean NaC in class 2 and class 3 was significantly lower than in class 1 (-3.9 mmol/l; 95% confidence interval [CI] -7.1 to -0.8, p = 0.01 and -5.2 mmol/l; 95% CI -7.9 to -2.5, p < 0.001, respectively). Mean serum NaC was not significantly associated with any of the 14 individually assessed drug classes. In addition to latent class, increasing age and higher eGFR were also independently associated with lower serum NaC (p = 0.002 and p = 0.03, respectively). LCA enabled us to identify patterns of drug use associated with lower serum NaC in older inpatients. Our results suggest that older patients using antiplatelets or anticoagulants are especially at risk of lower serum NaC.

Classes of conduct disorder symptoms and their life course correlates in a US national sample.

PubMed

Breslau, J; Saito, N; Tancredi, D J; Nock, M; Gilman, S E

2012-05-01

Population data on conduct disorder (CD) symptoms can help determine whether hypothesized subtypes of CD are sufficiently disparate in their familial, psychiatric and life course correlates to distinguish separate diagnostic entities. Latent class analysis (LCA) of CD symptoms occurring before age 15 was conducted in a national sample of adults aged 18-44 years from the National Epidemiological Study of Alcohol and Related Conditions. Associations of latent class membership with parental behavior problems, onset of psychiatric disorders and anti-social behaviors after age 15, adolescent life events (e.g. high school drop-out), and past-year life events (e.g. divorce/separation, bankruptcy) were estimated. LCA identified a no-CD class with low prevalence of all symptoms, three intermediate classes - deceit/theft, rule violations, aggression - and a severe class. The prevalence of CD, according to DSM-IV criteria, was 0% in the no-CD class, between 13.33% and 33.69% in the intermediate classes and 62.20% in the severe class. Latent class membership is associated with all the familial, psychiatric and life course outcomes examined. Among the intermediate classes, risk for subsequent mood/anxiety disorders and anti-social behavior was higher in the deceit/theft and aggressive classes than in the rule violations class. However, risk for adolescent life events is highest in the rule violations class. CD symptoms tend to occur in a partially ordered set of classes in the general population. Prognostically meaningful distinctions can be drawn between classes, but only at low levels of symptoms.

Occurence of internet addiction in a general population sample: a latent class analysis.

PubMed

Rumpf, Hans-Jürgen; Vermulst, Ad A; Bischof, Anja; Kastirke, Nadin; Gürtler, Diana; Bischof, Gallus; Meerkerk, Gert-Jan; John, Ulrich; Meyer, Christian

2014-01-01

Prevalence studies of Internet addiction in the general population are rare. In addition, a lack of approved criteria hampers estimation of its occurrence. This study conducted a latent class analysis (LCA) in a large general population sample to estimate prevalence. A telephone survey was conducted based on a random digit dialling procedure including landline telephone (n=14,022) and cell phone numbers (n=1,001) in participants aged 14-64. The Compulsive Internet Use Scale (CIUS) served as the basis for a LCA used to look for subgroups representing participants with Internet addiction or at-risk use. CIUS was given to participants reporting to use the Internet for private purposes at least 1 h on a typical weekday or at least 1 h on a day at the weekend (n=8,130). A 6-class model showed best model fit and included two groups likely to represent Internet addiction and at-risk Internet use. Both groups showed less social participation and the Internet addiction group less general trust in other people. Proportions of probable Internet addiction were 1.0% (CI 0.9-1.2) among the entire sample, 2.4% (CI 1.9-3.1) in the age group 14-24, and 4.0% (CI 2.7-5.7) in the age group 14-16. No difference in estimated proportions between males and females was found. Unemployment (OR 3.13; CI 1.74-5.65) and migration background (OR 3.04; CI 2.12-4.36) were related to Internet addiction. This LCA-based study differentiated groups likely to have Internet addiction and at-risk use in the general population and provides characteristics to further define this rather new disorder. © 2013 S. Karger AG, Basel.

A latent class approach to understanding patterns of peer victimization in four low-resource settings.

PubMed

Nguyen, Amanda J; Bradshaw, Catherine; Townsend, Lisa; Gross, Alden L; Bass, Judith

2016-08-17

Peer victimization is a common form of aggression among school-aged youth, but research is sparse regarding victimization dynamics in low- and middle-income countries (LMIC). Person-centered approaches have demonstrated utility in understanding patterns of victimization in the USA. We aimed to empirically identify classes of youth with unique victimization patterns in four LMIC settings using latent class analysis (LCA). We used data on past-year exposure to nine forms of victimization reported by 3536 youth (aged 15 years) from the Young Lives (YL) study in Ethiopia, India (Andhra Pradesh and Telangana states), Peru, and Vietnam. Sex and rural/urban context were examined as predictors of class membership. LCA supported a 2-class model in Peru, a 3-class model in Ethiopia and Vietnam, and a 4-class model in India. Classes were predominantly ordered by severity, suggesting that youth who experienced one form of victimization were likely to experience other forms as well. In India, two unordered classes were also observed, characterized by direct and indirect victimization. Boys were more likely than girls to be in the highly victimized (HV) class in Ethiopia and India. Urban contexts, compared with rural, conferred higher risk of victimization in Ethiopia and Peru, and lower risk in India and Vietnam. The identified patterns of multiple forms of victimization highlight a limitation of common researcher-driven classifications and suggest avenues for future person-centered research to improve intervention development in LMIC settings.

A latent class analysis of drug abuse in a national Swedish sample.

PubMed

Kendler, K S; Ohlsson, H; Sundquist, K; Sundquist, J

2013-10-01

Drug abuse (DA) is a clinically heterogeneous syndrome. Using medical, legal, death and pharmacy records covering the entire population of Sweden, could we uncover meaningful subtypes of DA? We performed a latent class analysis (LCA) on all individuals in Sweden born 1950–1993 who were registered with DA or its consequences (n=192,501) and then validated these classes using demographics, patterns of co-morbidity with alcohol use disorder (AUD), non-DA crime and psychiatric illness, and the pattern of aggregation and co-aggregation in sibling pairs. The best-fit LCA had six classes : (1) low-frequency pure criminal, (2) high-frequency medical criminal, (3) low-frequency pure medical, (4) high-frequency medical, (5) prescription and (6) death. Each class had a distinct pattern of demographic features and co-morbidity and aggregated within sibling pairs with at least moderate specificity. For example, class 2 was characterized by early age at registration, low educational attainment, high male preponderance, high rates of AUDs, strong resemblance within sibling pairs [odds ratio (OR) 12.6] and crime and the highest risk for DA in siblings (20.0%). By contrast, class 5 had a female preponderance, late age at registration, low rates of crime and AUDs, high rates of psychiatric illness, high familiality within sibling pairs (OR 14.7) but the lowest observed risk for DA in siblings (8.9%). DA as assessed by public records is a heterogeneous syndrome. Familial factors contribute substantially to this heterogeneity. Advances in our understanding of etiological processes leading to DA will be aided by a consideration of this heterogeneity.

Instructor and peer bullying in college students: Distinct typologies based on Latent Class Analysis.

PubMed

Marraccini, Marisa E; Brick, Leslie Ann D; Weyandt, Lisa L

2018-03-22

Although bullying is traditionally considered within the context of primary and secondary school, recent evidence suggests that bullying continues into college and workplace settings. Participants/Method: Latent class analysis (LCA) was employed to classify college bullying involvement typologies among 325 college students attending a northeastern university. Four classes concerning bullying involvement were revealed: Non-involved (36%); Instructor victim (30%); Peer bully-victim (22%); and Peer bully-victim/ Instructor victim (12%). Findings from this study, which classified college bullying experiences by incorporating both peer and instructor (teacher and professor) bullying, add substantially to the literature by providing insight into patterns of relatively unexplored bullying behaviors.

Latent Classes and Cumulative Impacts of Adverse Childhood Experiences.

PubMed

Barboza, Gia Elise

2018-05-01

Studies of adverse childhood experiences (ACEs) have gauged severity using a cumulative risk (CR) index. Few studies have focused on the nature of the context of adversity and their association with psychosocial outcomes. The objective of this study was to examine the patterning of ACEs and to explore the resultant patterns' association with HIV risk-taking, problem drinking, and depressive symptoms in adulthood. Latent class analysis (LCA) was used to identify homogeneous, mutually exclusive "classes" of 11 of the most commonly used ACEs. The LCA resulted in four high-risk profiles and one low-risk profile, which were labeled: (1) highly abusive and dysfunctional (3.3%; n = 1,983), (2) emotionally abusive alcoholic with parental conflict (6%, n = 3,303), (3) sexual abuse only (4.3%, n = 2,260), (4) emotionally abusive and alcoholic (30.3%, n = 17,460), and (5) normative, low risk (56.3%, n = 32,950). Compared to the low-risk class, each high-risk profile was differentially associated with adult psychosocial outcomes even when the conditional CR within that class was similar. The results further our understanding about the pattern of ACEs and the unique pathways to poor health. Implications for child welfare systems when dealing with individuals who have experienced multiple forms of early childhood maltreatment and/or household dysfunction are discussed.

Understanding Teacher Users of a Digital Library Service: A Clustering Approach

ERIC Educational Resources Information Center

Xu, Beijie

2011-01-01

This research examined teachers' online behaviors while using a digital library service--the Instructional Architect (IA)--through three consecutive studies. In the first two studies, a statistical model called latent class analysis (LCA) was applied to cluster different groups of IA teachers according to their diverse online behaviors. The third…

A Systematic Evaluation of ADHD and Comorbid Psychopathology in a Population-Based Twin Sample

ERIC Educational Resources Information Center

Volk, Heather E.; Neuman, Rosalind J.; Todd, Richard D.

2005-01-01

Objective: Clinical and population samples demonstrate that attention-deficit/hyperactivity disorder (ADHD) occurs with other disorders. Comorbid disorder clustering within ADHD subtypes is not well studied. Method: Latent class analysis (LCA) examined the co-occurrence of DSM-IV ADHD, oppositional defiant disorder (ODD), conduct disorder (CD),…

Investigating Visitor Profiles as a Valuable Addition to Museum Research

ERIC Educational Resources Information Center

Lewalter, Doris; Phelan, Siëlle; Geyer, Claudia; Specht, Inga; Grüninger, Rahel; Schnotz, Wolfgang

2015-01-01

There is a long tradition of museum research assessing visitors' personal background. In this article, we suggest an insightful way to enhance and intensify visitor analyses and adopt a more integrative approach. To this end, we draw attention to Latent Class Analysis (LCA), a classification method that allows us to investigate visitor profiles…

Rapid Diagnostic Test Performance Assessed Using Latent Class Analysis for the Diagnosis of Plasmodium falciparum Placental Malaria.

PubMed

Liu, Yunhao; Mwapasa, Victor; Khairallah, Carole; Thwai, Kyaw L; Kalilani-Phiri, Linda; Ter Kuile, Feiko O; Meshnick, Steven R; Taylor, Steve M

2016-10-05

Placental malaria causes low birth weight and neonatal mortality in malaria-endemic areas. The diagnosis of placental malaria is important for program evaluation and clinical care, but is compromised by the suboptimal performance of current diagnostics. Using placental and peripheral blood specimens collected from delivering women in Malawi, we compared estimation of the operating characteristics of microscopy, rapid diagnostic test (RDT), polymerase chain reaction, and histopathology using both a traditional contingency table and a latent class analysis (LCA) approach. The prevalence of placental malaria by histopathology was 13.8%; concordance between tests was generally poor. Relative to histopathology, RDT sensitivity was 79.5% in peripheral and 66.2% in placental blood; using LCA, RDT sensitivities increased to 93.7% and 80.2%, respectively. Our results, if replicated in other cohorts, indicate that RDT testing of peripheral or placental blood may be suitable approaches to detect placental malaria for surveillance programs, including areas where intermittent preventive therapy in pregnancy is not used. © The American Society of Tropical Medicine and Hygiene.

Content Themes of Alcohol Advertising in U.S. Television-Latent Class Analysis.

PubMed

Morgenstern, Matthis; Schoeppe, Franziska; Campbell, Julie; Braam, Marloes W G; Stoolmiller, Michael; Sargent, James D

2015-09-01

There is little alcohol research that reports on the thematic contents of contemporary alcohol advertisements in U.S. television. Studies of alcohol ads from 2 decades ago did not identify "Partying" as a social theme. Aim of this study was to describe and classify alcohol advertisements aired in national television in terms of contents, airing times, and channel placements and to identify different marketing strategies of alcohol brands. Content analysis of all ads from the top 20 U.S. beer and spirit brands aired between July 2009 and June 2011. These were 581 unique alcohol ads accounting for 272,828 (78%) national television airings. Ads were coded according to predefined definitions of 13 content areas. A latent class analysis (LCA) was conducted to define content cluster themes and determine alcoholic brands that were more likely to exploit these themes. About half of the advertisements (46%) were aired between 3 am and 8 pm, and the majority were placed either in Entertainment (40%) and Sports (38%) channels. Beer ads comprised 64% of the sample, with significant variation in airing times and channels between types of products and brands. LCA revealed 5 content classes that exploited the "Partying," "Quality," "Sports," "Manly," and "Relax" themes. The partying class, indicative of ad messages surrounding partying, love, and sex, was the dominant theme comprising 42% of all advertisements. Ads for alcopops, flavored spirits, and liqueur were more likely to belong to the party class, but there were also some beer brands (Corona, Heineken) where more than 67% of ads exploited this theme. This is the first analysis to identify a partying theme to contemporary alcohol advertising. Future analyses can now determine whether exposure to that or other themes predicts alcohol misuse among youth audiences. Copyright © 2015 by the Research Society on Alcoholism.

Predominant typologies of psychopathology in the United States: a latent class analysis.

PubMed

El-Gabalawy, Renée; Tsai, Jack; Harpaz-Rotem, Ilan; Hoff, Rani; Sareen, Jitender; Pietrzak, Robert H

2013-11-01

Latent class analysis (LCA) offers a parsimonious way of classifying common typologies of psychiatric comorbidity. We used LCA to identify the nature and correlates of predominant typologies of Axis I and II disorders in a large and comprehensive population-based sample of U.S. adults. We analyzed data from Wave 2 of the National Epidemiologic Survey on Alcohol and Related Conditions (2004-2005; n = 34,653), a population-based sample of U.S. adults. We derived latent classes based on all assessed Axis I and II disorders and examined the relationship between the identified Axis I classes and lifetime psychiatric disorders and suicide attempts, and physical and mental health-related quality of life. A four-class solution was optimal in characterizing predominant typologies of both Axis I and II disorders. For Axis I disorders, these included low psychopathology (n = 28,935, 84.0%), internalizing (n = 3693, 9.9%), externalizing (n = 1426, 4.5%), and high psychopathology (n = 599, 1.6%) classes. For Axis II disorders, these included no/low personality disorders (n = 31,265, 90.9%), obsessive/paranoid (n = 1635, 4.6%), borderline/dysregulated (n = 1319, 3.4%), and highly comorbid (n = 434, 1.1%) classes. Compared to the low psychopathology class, all other Axis I classes had significantly increased odds of mental disorders, elevated Axis II classes, suicide attempts and poorer quality of life, with the high psychopathology class having the overall highest rates of these correlates, with the exception of substance use disorders. Compared to the low psychopathology class, the internalizing and externalizing classes had increased rates of mood and anxiety disorders, and substance use disorders, respectively. Axis I and II psychopathology among U.S. adults may be best represented by four predominant typologies. Characterizing co-occurring patterns of psychopathology using person-based typologies represents a higher-order classification system that may be useful in clinical and research settings. Published by Elsevier Ltd.

Can the dissociative PTSD subtype be identified across two distinct trauma samples meeting caseness for PTSD?

PubMed

Hansen, Maj; Műllerová, Jana; Elklit, Ask; Armour, Cherie

2016-08-01

For over a century, the occurrence of dissociative symptoms in connection to traumatic exposure has been acknowledged in the scientific literature. Recently, the importance of dissociation has also been recognized in the long-term traumatic response within the DSM-5 nomenclature. Several studies have confirmed the existence of the dissociative posttraumatic stress disorder (PTSD) subtype. However, there is a lack of studies investigating latent profiles of PTSD solely in victims with PTSD. This study investigates the possible presence of PTSD subtypes using latent class analysis (LCA) across two distinct trauma samples meeting caseness for DSM-5 PTSD based on self-reports (N = 787). Moreover, we assessed if a number of risk factors resulted in an increased probability of membership in a dissociative compared with a non-dissociative PTSD class. The results of LCA revealed a two-class solution with two highly symptomatic classes: a dissociative class and a non-dissociative class across both samples. Increased emotion-focused coping increased the probability of individuals being grouped into the dissociative class across both samples. Social support reduced the probability of individuals being grouped into the dissociative class but only in the victims of motor vehicle accidents (MVAs) suffering from whiplash. The results are discussed in light of their clinical implications and suggest that the dissociative subtype can be identified in victims of incest and victims of MVA suffering from whiplash meeting caseness for DSM-5 PTSD.

Using existing questionnaires in latent class analysis: should we use summary scores or single items as input? A methodological study using a cohort of patients with low back pain.

PubMed

Nielsen, Anne Molgaard; Vach, Werner; Kent, Peter; Hestbaek, Lise; Kongsted, Alice

2016-01-01

Latent class analysis (LCA) is increasingly being used in health research, but optimal approaches to handling complex clinical data are unclear. One issue is that commonly used questionnaires are multidimensional, but expressed as summary scores. Using the example of low back pain (LBP), the aim of this study was to explore and descriptively compare the application of LCA when using questionnaire summary scores and when using single items to subgrouping of patients based on multidimensional data. Baseline data from 928 LBP patients in an observational study were classified into four health domains (psychology, pain, activity, and participation) using the World Health Organization's International Classification of Functioning, Disability, and Health framework. LCA was performed within each health domain using the strategies of summary-score and single-item analyses. The resulting subgroups were descriptively compared using statistical measures and clinical interpretability. For each health domain, the preferred model solution ranged from five to seven subgroups for the summary-score strategy and seven to eight subgroups for the single-item strategy. There was considerable overlap between the results of the two strategies, indicating that they were reflecting the same underlying data structure. However, in three of the four health domains, the single-item strategy resulted in a more nuanced description, in terms of more subgroups and more distinct clinical characteristics. In these data, application of both the summary-score strategy and the single-item strategy in the LCA subgrouping resulted in clinically interpretable subgroups, but the single-item strategy generally revealed more distinguishing characteristics. These results 1) warrant further analyses in other data sets to determine the consistency of this finding, and 2) warrant investigation in longitudinal data to test whether the finer detail provided by the single-item strategy results in improved prediction of outcomes and treatment response.

Rule Following and Rule Use in the Balance-Scale Task

ERIC Educational Resources Information Center

Shultz, Thomas R.; Takane, Yoshio

2007-01-01

Quinlan et al. [Quinlan, p., van der Mass, H., Jansen, B., Booij, O., & Rendell, M. (this issue). Re-thinking stages of cognitive development: An appraisal of connectionist models of the balance scale task. "Cognition", doi:10.1016/j.cognition.2006.02.004] use Latent Class Analysis (LCA) to criticize a connectionist model of development on the…

Self-efficacy difference among patients with cancer with different socioeconomic status: application of latent class analysis and standardization and decomposition analysis.

PubMed

Yuan, Changrong; Wei, Chunlan; Wang, Jichuan; Qian, Huijuan; Ye, Xianghong; Liu, Yingyan; Hinds, Pamela S

2014-06-01

Although the relationship between partial socioeconomic status (SES) and self-efficacy has been studied in previous studies, few research have examined self-efficacy difference among patients with cancer with different SES. A cross-sectional survey involving 764 patients with cancer was completed. Latent class analysis (LCA) was applied to identify distinct groups of patients with cancer using four SES indicators (education, income, employment status and health insurance status). Standardization and decomposition analysis (SDA) was then used to examine differences in patients' self-efficacy among SES groups and the components of the differences attributed to confounding factors, such as gender, age, anxiety, depression and social support. Participants were classified into four distinctive SES groups via using LCA method, and the observed self-efficacy level significantly varied by SES groups; as theorized, higher self-efficacy was associated with higher SES. The self-efficacy differences by SES groups were decomposed into "real" group differences and factor component effects that are attributed to group differences in confounding factor compositions. Self-efficacy significantly varies by SES. Social support significantly confounded the observed differences in self-efficacy between different SES groups among Chinese patients with cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

Empirically derived lifespan polytraumatization typologies: A systematic review.

PubMed

Contractor, Ateka A; Caldas, Stephanie; Fletcher, Shelley; Shea, M Tracie; Armour, Cherie

2018-07-01

Polytraumatization classes based on trauma endorsement patterns relate to distinct clinical outcomes. Person-centered approaches robustly evaluate the nature, and construct validity of polytraumatization classes. Our review examined evidence for the nature and construct validity of lifespan polytraumatization typologies. In September 2016, we searched Pubmed, PSYCINFO, PSYC ARTICLES, Academic Search Complete, PILPTS, Web of Science, CINAHL, Medline, PsycEXTRA, and PBSC. Search terms included "latent profile," "latent class," "latent analysis," "person-centered," "polytrauma," "polyvictimization," "traumatization," "lifetime," "cooccurring," "complex," "typology," "multidimensional," "sequential," "multiple," "subtype," "(re)victimization," "cumulative," "maltreatment," "abuse," and "stressor." Inclusionary criteria included: peer-reviewed; latent class/latent profile analyses (LCA/LPA) of lifespan polytrauma classes; adult samples of size greater than 200; only trauma types as LCA/LPA indicators; mental health correlates of typologies; and individual-level trauma assessment. Of 1,397 articles, nine met inclusion criteria. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, research assistants completed a secondary reference search, and independently extracted data with standardized coding forms. Three-class (n = 5) or four-class (n = 4) solutions were found. Seven studies found a class characterized by higher trauma endorsement (high-trauma). All studies found a class characterized by lower trauma endorsement (low-trauma), and predominance of specific traumas (specific-trauma; e.g., childhood maltreatment). High-trauma versus low-trauma classes and specific-trauma versus low-trauma classes differed on mental health correlates. Evidence supports the prevalence of a high-trauma class experiencing poorer mental health, and the detrimental impact of aggregated interpersonal and other traumas. We highlight the clinical importance of addressing polytraumatization classes, and comprehensively assessing the impact of all traumas. © 2018 Wiley Periodicals, Inc.

Determinants of Patient Satisfaction Two Year after Spinal Deformity Surgery: A Latent Class Analysis.

PubMed

Yang, Jingyan; Lafage, Virginie; Lafage, Renaud; Smith, Justin; Klineberg, Eric O; Shaffrey, Christopher I; Mundis, Gregory; Hostin, Richard; Burton, Douglas; Ames, Christopher P; Bess, Shay; Kim, Han Jo; Schwab, Frank

2018-06-21

Retrospective review of prospective multicenter database. To investigate the determinants of patient satisfaction with respect to changes in functional limitations two-year after spinal deformity surgery. For operatively treated adult spine deformity (ASD), patient satisfaction has become an important component of evaluating quality of care. 430 operative ASD patients with two-year follow-up were analyzed. Patient satisfaction was assessed using the Scoliosis Research Society 22-item (SRS-22r). Latent class analysis (LCA) was performed to assign individuals to classes based on the changes in pre- and 2-year post-operative functions, assessed using the Oswestry Disability Index (ODI). An ordered logistic regression was conducted to assess the association of class membership and satisfaction. LCA identified 4 classes. The worsened-condition class (WC: 1.4%) consisted of patients who were likely to experience worsened function, particularly in lifting and pain intensity. The remained-same class (RS: 13.0%) included patients who remained the same, as the majority reported approximately no change in walking, standing and sitting. The mild-improved class (Mild-I: 40.2%) included patients with mildly enhanced conditions, specifically, in standing, social life and employment. The most-improved class (Most-I: 45.3%) included patients with great improvement after surgery mainly in standing, followed by social life and employment. The odds of being satisfied were significantly increased by 3.91-(p < 0.001) and 16.99-fold (p < 0.001), comparing patients in Mild-I and Most-I to the RS/WC class, respectively, after controlling for confounders. Improvement in standing, social life and employment are the most important determinants of patient satisfaction post-surgery. Reduced pain intensity and enhanced walking ability also help to elevate patient satisfaction. However, lifting, personal care, sitting, sleeping and travelling may be of less importance. Examining the heterogeneity of patient-reported outcome in ASD patients allows the identification of classes with different patient characteristics and satisfaction, and thus, help to guide tailored provision of care. 4.

Maternal eating disorder and infant diet. A latent class analysis based on the Norwegian Mother and Child Cohort Study (MoBa).

PubMed

Torgersen, Leila; Ystrom, Eivind; Siega-Riz, Anna Maria; Berg, Cecilie Knoph; Zerwas, Stephanie C; Reichborn-Kjennerud, Ted; Bulik, Cynthia M

2015-01-01

Knowledge of infant diet and feeding practices among children of mothers with eating disorders is essential to promote healthy eating in these children. This study compared the dietary patterns of 6-month-old children of mothers with anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorder not otherwise specified-purging subtype, to the diet of children of mothers with no eating disorders (reference group). The study was based on 53,879 mothers in the Norwegian Mother and Child Cohort Study (MoBa). Latent class analysis (LCA) was used to identify discrete latent classes of infant diet based on the mothers' responses to questions about 16 food items. LCA identified five classes, characterized by primarily homemade vegetarian food (4% of infants), homemade traditional food (8%), commercial cereals (35%), commercial jarred baby food (39%), and a mix of all food groups (11%). The association between latent dietary classes and maternal eating disorders were estimated by multinomial logistic regression. Infants of mothers with bulimia nervosa had a lower probability of being in the homemade traditional food class compared to the commercial jarred baby food class, than the referent (O.R. 0.59; 95% CI 0.36-0.99). Infants of mothers with binge eating disorder had a lower probability of being in the homemade vegetarian class compared to the commercial jarred baby food class (O.R. 0.77; 95% CI 0.60-0.99), but only before adjusting for relevant confounders. Anorexia nervosa and eating disorder not otherwise specified-purging subtype were not statistically significantly associated with any of the dietary classes. These results suggest that maternal eating disorders may to some extent influence the child's diet at 6 months; however, the extent to which these differences influence child health and development remains an area for further inquiry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Testing Pneumonia Vaccines in the Elderly: Determining a Case Definition for Pneumococcal Pneumonia in the Absence of a Gold Standard.

PubMed

Jokinen, Jukka; Snellman, Marja; Palmu, Arto A; Saukkoriipi, Annika; Verlant, Vincent; Pascal, Thierry; Devaster, Jeanne-Marie; Hausdorff, William P; Kilpi, Terhi M

2018-06-01

Clinical assessments of vaccines to prevent pneumococcal community-acquired pneumonia (CAP) require sensitive and specific case definitions, but there is no gold standard diagnostic test. To develop a new case definition suitable for vaccine efficacy studies, we applied latent class analysis (LCA) to the results from 7 diagnostic tests for pneumococcal etiology on clinical specimens from 323 elderly persons with radiologically confirmed pneumonia enrolled in the Finnish Community-Acquired Pneumonia Epidemiology study during 2005-2007. Compared with the conventional use of LCA, which is mainly to determine sensitivities and specificities of different tests, we instead used LCA as an appropriate instrument to predict the probability of pneumococcal etiology for each CAP case based on individual test profiles, and we used the predictions to minimize the sample size that would be needed for a vaccine efficacy trial. When compared with the conventional laboratory criteria of encapsulated pneumococci in culture, in blood culture or high-quality sputum culture, or urine antigen positivity, our optimized case definition for pneumococcal CAP resulted in a trial sample size that was almost 20,000 subjects smaller. We believe that the novel application of LCA detailed here to determine a case definition for pneumococcal CAP could also be similarly applied to other diseases without a gold standard.

Differentiation of functional constipation and constipation predominant irritable bowel syndrome based on Rome III criteria: a population-based study.

PubMed

Koloski, N A; Jones, M; Young, M; Talley, N J

2015-05-01

While the Rome III classification recognises functional constipation (FC) and constipation predominant IBS (IBS-C) as distinct disorders, recent evidence has suggested that these disorders are difficult to separate in clinical practice. To identify whether clinical and lifestyle factors differentiate Rome III-defined IBS-C from FC based on gastrointestinal symptoms and lifestyle characteristics. 3260 people randomly selected from the Australian population returned a postal survey. FC and IBS-C were defined according to Rome III. The first model used logistic regression to differentiate IBS-C from FC based on lifestyle, quality-of-life and psychological characteristics. The second approach was data-driven employing latent class analysis (LCA) to identify naturally occurring clusters in the data considering all symptoms involved in the Rome III criteria for IBS-C and FC. We found n = 206 (6.5%; 95% CI 5.7-7.4%) people met strict Rome III FC whereas n = 109 (3.5%; 95% CI 2.8-4.1%) met strict Rome III IBS-C. The case-control approach indicated that FC patients reported an older age at onset of constipation, were less likely to exercise, had higher mental QoL and less health care seeking than IBS-C. LCA yielded one latent class that was predominantly (75%) FC, while the other class was approximately half IBS-C and half FC. The FC-dominated latent class had clearly lower levels of symptoms used to classify IBS (pain-related symptoms) and was more likely to be male (P = 0.046) but was otherwise similar in distribution of lifestyle factors to the mixed class. The latent class analysis approach suggests a differentiation based more on symptom severity rather than the Rome III view. © 2015 John Wiley & Sons Ltd.

Movements and Spatial Use of False Killer Whales in Hawaii: Satellite Tagging Studies in 2009

DTIC Science & Technology

2011-02-07

with estimated error of between 500 and 1 500 m), as well as LC0 , LCA, LCB, and LCZ locations (with no estimation of accuracy) were only retained...for each individual that passed the Douglas Argos-Filter, by location class (LC) ID # locations after filtering LC3 LC2 LC1 LC0 LCA LCB LCZ

Dyadic Taxonomy of Delinquent Youth: Exploring Risks and Outcomes Associated With Maternal-Youth Reporting Discrepancies of Delinquent Behavior

ERIC Educational Resources Information Center

Reid, Joan A.; Sullivan, Christopher J.

2016-01-01

Using latent class analysis (LCA), this study identified a dyadic taxonomy of delinquent youth categorized by varying types of maternal-youth reporting discrepancies (i.e., youth < maternal, youth > maternal) within a sample of 764 14-year-old high-risk youth. Four distinctive subgroups of youth were identified, two of which reported more…

The Association of Latino Children's Kindergarten School Readiness Profiles with Grade 2-5 Literacy Achievement Trajectories

ERIC Educational Resources Information Center

Quirk, Matthew; Grimm, Ryan; Furlong, Michael J.; Nylund-Gibson, Karen; Swami, Sruthi

2016-01-01

This study utilized latent class analysis (LCA) to identify 5 discernible profiles of Latino children's (N = 1,253) social-emotional, physical, and cognitive school readiness at the time of kindergarten entry. In addition, a growth mixture modeling (GMM) approach was used to identify 3 unique literacy achievement trajectories, across Grades 2-5,…

Bayesian Latent Class Analysis Tutorial.

PubMed

Li, Yuelin; Lord-Bessen, Jennifer; Shiyko, Mariya; Loeb, Rebecca

2018-01-01

This article is a how-to guide on Bayesian computation using Gibbs sampling, demonstrated in the context of Latent Class Analysis (LCA). It is written for students in quantitative psychology or related fields who have a working knowledge of Bayes Theorem and conditional probability and have experience in writing computer programs in the statistical language R . The overall goals are to provide an accessible and self-contained tutorial, along with a practical computation tool. We begin with how Bayesian computation is typically described in academic articles. Technical difficulties are addressed by a hypothetical, worked-out example. We show how Bayesian computation can be broken down into a series of simpler calculations, which can then be assembled together to complete a computationally more complex model. The details are described much more explicitly than what is typically available in elementary introductions to Bayesian modeling so that readers are not overwhelmed by the mathematics. Moreover, the provided computer program shows how Bayesian LCA can be implemented with relative ease. The computer program is then applied in a large, real-world data set and explained line-by-line. We outline the general steps in how to extend these considerations to other methodological applications. We conclude with suggestions for further readings.

Patterns of adverse childhood experiences and substance use among young adults: A latent class analysis.

PubMed

Shin, Sunny H; McDonald, Shelby Elaine; Conley, David

2018-03-01

Adverse childhood experiences (ACEs) have been strongly linked with subsequent substance use. The aim of this study was to investigate how different patterns of ACEs influence substance use in young adulthood. Using a community sample of young individuals (N=336; ages 18-25), we performed latent class analyses (LCA) to identify homogenous groups of young people with similar patterns of ACEs. Exposure to ACEs incorporates 13 childhood adversities including childhood maltreatment, household dysfunction, and community violence. Multiple linear and logistic regression models were used in an effort to examine the associations between ACEs classes and four young adult outcomes such as alcohol-related problems, current tobacco use, drug dependence symptoms, and psychological distress. LCA identified four heterogeneous classes of young people distinguished by different patterns of ACEs exposure: Low ACEs (56%), Household Dysfunction/Community Violence (14%), Emotional ACEs (14%), and High/Multiple ACEs (16%). Multiple regression analyses found that compared to those in the Low ACEs class, young adults in the High/Multiple ACEs class reported more alcohol-related problems, current tobacco use, and psychological symptoms, controlling for sociodemographic characteristics and common risk factors for substance use such as peer substance use. Our findings confirm that for many young people, ACEs occur as multiple rather than single experiences. The results of this research suggest that exposure to poly-victimization during childhood is particularly related to substance use during young adulthood. Copyright © 2017 Elsevier Ltd. All rights reserved.

National youth sedentary behavior and physical activity daily patterns using latent class analysis applied to accelerometry.

PubMed

Evenson, Kelly R; Wen, Fang; Hales, Derek; Herring, Amy H

2016-05-03

Applying latent class analysis (LCA) to accelerometry can help elucidated underlying patterns. This study described the patterns of accelerometer-determined sedentary behavior and physical activity among youth by applying LCA to a nationally representative United States (US) sample. Using 2003-2006 National Health and Nutrition Examination Survey data, 3998 youths 6-17 years wore an ActiGraph 7164 accelerometer for one week, providing > =3 days of wear for > =8 h/day from 6:00 am-midnight. Cutpoints defined sedentary behavior (<100 counts/minute), light activity (100-2295 counts/minute), moderate to vigorous physical activity (MVPA; > = 2296 counts/minute), and vigorous activity (> = 4012 counts/minute). To account for wear time differences, outcomes were expressed as percent of day in a given intensity. LCA was used to classify daily (Monday through Sunday) patterns of average counts/minute, sedentary behavior, light activity, MVPA, and vigorous activity separately. The latent classes were explored overall and by age (6-11, 12-14, 15-17 years), gender, and whether or not youth attended school during measurement. Estimates were weighted to account for the sampling frame. For average counts/minute/day, four classes emerged from least to most active: 40.9% of population (mean 323.5 counts/minute/day), 40.3% (559.6 counts/minute/day), 16.5% (810.0 counts/minute/day), and 2.3% (1132.9 counts/minute/day). For percent of sedentary behavior, four classes emerged: 13.5% of population (mean 544.6 min/day), 30.1% (455.1 min/day), 38.5% (357.7 min/day), and 18.0% (259.2 min/day). For percent of light activity, four classes emerged: 12.3% of population (mean 222.6 min/day), 29.3% (301.7 min/day), 41.8% (384.0 min/day), and 16.6% (455.5 min/day). For percent of MVPA, four classes emerged: 59.9% of population (mean 25.0 min/day), 33.3% (60.9 min/day), 3.1% (89.0 min/day), and 3.6% (109.3 min/day). For percent of vigorous activity, three classes emerged: 76.8% of population (mean 7.1 min/day), 18.5% (23.9 min/day), and 4.7% (47.4 min/day). Classes were developed by age, gender, and school attendance since some patterns differed when stratifying by these factors. The models supported patterns for average intensity, sedentary behavior, light activity, MVPA, and vigorous activity. These latent class derived patterns can be used in other youth studies to explore correlates or outcomes and to target sedentary behavior or physical activity interventions.

PTSD symptom severity and psychiatric comorbidity in recent motor vehicle accident victims: a latent class analysis.

PubMed

Hruska, Bryce; Irish, Leah A; Pacella, Maria L; Sledjeski, Eve M; Delahanty, Douglas L

2014-10-01

We conducted a latent class analysis (LCA) on 249 recent motor vehicle accident (MVA) victims to examine subgroups that differed in posttraumatic stress disorder (PTSD) symptom severity, current major depressive disorder and alcohol/other drug use disorders (MDD/AoDs), gender, and interpersonal trauma history 6-weeks post-MVA. A 4-class model best fit the data with a resilient class displaying asymptomatic PTSD symptom levels/low levels of comorbid disorders; a mild psychopathology class displaying mild PTSD symptom severity and current MDD; a moderate psychopathology class displaying severe PTSD symptom severity and current MDD/AoDs; and a severe psychopathology class displaying extreme PTSD symptom severity and current MDD. Classes also differed with respect to gender composition and history of interpersonal trauma experience. These findings may aid in the development of targeted interventions for recent MVA victims through the identification of subgroups distinguished by different patterns of psychiatric problems experienced 6-weeks post-MVA. Copyright © 2014 Elsevier Ltd. All rights reserved.

PTSD Symptom Severity and Psychiatric Comorbidity in Recent Motor Vehicle Accident Victims: A Latent Class Analysis

PubMed Central

Hruska, Bryce; Irish, Leah A.; Pacella, Maria L.; Sledjeski, Eve M.; Delahanty, Douglas L.

2014-01-01

We conducted a latent class analysis (LCA) on 249 recent motor vehicle accident (MVA) victims to examine subgroups that differed in posttraumatic stress disorder (PTSD) symptom severity, current major depressive disorder and alcohol/other drug use disorders (MDD/AoDs), gender, and interpersonal trauma history 6-weeks post-MVA. A 4-class model best fit the data with a resilient class displaying asymptomatic PTSD symptom levels/low levels of comorbid disorders; a mild psychopathology class displaying mild PTSD symptom severity and current MDD; a moderate psychopathology class displaying severe PTSD symptom severity and current MDD/AoDs; and a severe psychopathology class displaying extreme PTSD symptom severity and current MDD. Classes also differed with respect to gender composition and history of interpersonal trauma experience. These findings may aid in the development of targeted interventions for recent MVA victims through the identification of subgroups distinguished by different patterns of psychiatric problems experienced 6-weeks post-MVA. PMID:25124501

Empirical redefinition of comprehensive health and well-being in the older adults of the United States.

PubMed

McClintock, Martha K; Dale, William; Laumann, Edward O; Waite, Linda

2016-05-31

The World Health Organization (WHO) defines health as a "state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." Despite general acceptance of this comprehensive definition, there has been little rigorous scientific attempt to use it to measure and assess population health. Instead, the dominant model of health is a disease-centered Medical Model (MM), which actively ignores many relevant domains. In contrast to the MM, we approach this issue through a Comprehensive Model (CM) of health consistent with the WHO definition, giving statistically equal consideration to multiple health domains, including medical, physical, psychological, functional, and sensory measures. We apply a data-driven latent class analysis (LCA) to model 54 specific health variables from the National Social Life, Health, and Aging Project (NSHAP), a nationally representative sample of US community-dwelling older adults. We first apply the LCA to the MM, identifying five health classes differentiated primarily by having diabetes and hypertension. The CM identifies a broader range of six health classes, including two "emergent" classes completely obscured by the MM. We find that specific medical diagnoses (cancer and hypertension) and health behaviors (smoking) are far less important than mental health (loneliness), sensory function (hearing), mobility, and bone fractures in defining vulnerable health classes. Although the MM places two-thirds of the US population into "robust health" classes, the CM reveals that one-half belong to less healthy classes, independently associated with higher mortality. This reconceptualization has important implications for medical care delivery, preventive health practices, and resource allocation.

Content Themes of Alcohol Advertising in US Television — Latent Class Analysis

PubMed Central

Morgenstern, Matthis; Schoeppe, Franziska; Campbell, Julie; Braam, Marloes W.G.; Stoolmiller, Michael; Sargent, James D.

2015-01-01

Background There is little alcohol research that reports on the thematic contents of contemporary alcohol advertisements in US television. Studies of alcohol ads from two decades ago did not identify “partying” as a social theme. Aim of the present study was to describe and classify alcohol advertisements aired in national television in terms of contents, airing times, and channel placements and to identify different marketing strategies of alcohol brands. Methods Content analysis of all ads from the top 20 US beer and spirit brands aired between July 2009 and June 2011. These were 581 unique alcohol ads accounting for 272,828 (78%) national television airings. Ads were coded according to predefined definitions of 13 content areas. A latent class analysis (LCA) was conducted to define content cluster themes and determine alcoholic brands that were more likely to exploit these themes. Results About half of the advertisements (46%) were aired between 3am and 8pm, and the majority were placed either in Entertainment (40%) and Sports (38%) channels. Beer ads comprised 64% of the sample, with significant variation in airing times and channels between types of products and brands. LCA revealed five content classes that exploited the “Partying”, “Quality”, “Sports”, “Manly”, and “Relax” themes. The partying class, indicative of ad messages surrounding partying, love and sex, was the dominant theme, comprising 42% of all advertisements. Ads for alcopops, flavored spirits, and liqueur were more likely to belong to the party class, but there were also some beer brands (Corona, Heineken) where more than 67% of ads exploited this theme. Conclusions This is the first analysis to identify a partying theme to contemporary alcohol advertising. Future analyses can now determine whether exposure to that or other themes predicts alcohol misuse among youth audiences. PMID:26207317

Patterns of Alternative Tobacco Product Use: Emergence of Hookah and E-cigarettes as Preferred Products Amongst Youth.

PubMed

Gilreath, Tamika D; Leventhal, Adam; Barrington-Trimis, Jessica L; Unger, Jennifer B; Cruz, Tess Boley; Berhane, Kiros; Huh, Jimi; Urman, Robert; Wang, Kejia; Howland, Steve; Pentz, Mary Ann; Chou, Chih Ping; McConnell, Rob

2016-02-01

There is a growing public health concern related to the rapid increase in the use of multiple tobacco products among adolescents. This study examined patterns of adolescent use of cigarettes, e-cigarettes, cigars/cigarillo, hookah/waterpipe, and smokeless/dip/chewing tobacco in a population of southern California adolescents. Data from 2,097 11th- and 12th-grade participants in the Southern California Children's Health Study were collected via self-report in 2014. Study participants were asked about lifetime and current (past 30 days) use of cigarettes, cigars/cigarillos/little cigars, e-cigarettes, hookah/waterpipe, and smokeless/dip/chewing tobacco. Latent class analysis (LCA) was used to identify patterns of tobacco use. Hookah/waterpipe tobacco use had the highest current prevalence (10.7%) followed by e-cigarettes (9.6%). The prevalence of use of smokeless/dip/chewing tobacco was lowest, with 2.2% of adolescents reporting current use. The LCA suggested four distinct classes, comprising nonusers (72.3% of the sample), polytobacco experimenters (13.9%), e-cigarette/hookah users (8.2%), and polytobacco users (5.6%). Multinomial logistic regression based on these four classes found that males had double the odds to be polytobacco users relative to nonusers compared to females (odds ratio, 2.3; 95% confidence interval, 1.26-4.25). By identifying naturally occurring configurations of tobacco product use in teens, these findings may be useful to practitioners and policymakers to identify the need for tobacco control interventions that address specific tobacco products and particular combinations of polytobacco use. LCA can be used to identify segments of the population overrepresented among certain tobacco use classes (e.g., boys) that may benefit most from targeted polyproduct intervention approaches. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Coping Styles of Adolescents Experiencing Multiple Forms of Discrimination and Bullying: Evidence from a Sample of Ethnically Diverse Urban Youth

ERIC Educational Resources Information Center

Garnett, Bernice R.; Masyn, Katherine E.; Austin, S. Bryn; Williams, David R.; Viswanath, Kasisomayajula

2015-01-01

Background: We used a latent class analysis (LCA) to characterize coping styles of urban youth and examined if coping styles moderated the association between experiencing discrimination and bullying and depressive symptoms. Methods: The data come from the 2006 Boston Youth Survey, where students were asked to select 2 behaviors they do most often…

Towards Better Computational Models of the Balance Scale Task: A Reply to Shultz and Takane

ERIC Educational Resources Information Center

van der Maas, Han L. J.; Quinlan, Philip T.; Jansen, Brenda R. J.

2007-01-01

In contrast to Shultz and Takane [Shultz, T.R., & Takane, Y. (2007). Rule following and rule use in the balance-scale task. "Cognition", in press, doi:10.1016/j.cognition.2006.12.004.] we do not accept that the traditional Rule Assessment Method (RAM) of scoring responses on the balance scale task has advantages over latent class analysis (LCA):…

Social disinhibition is a heritable subphenotype of tics in Tourette syndrome

PubMed Central

Hirschtritt, Matthew E.; Darrow, Sabrina M.; Illmann, Cornelia; Osiecki, Lisa; Grados, Marco; Sandor, Paul; Dion, Yves; King, Robert A.; Pauls, David L.; Budman, Cathy L.; Cath, Danielle C.; Greenberg, Erica; Lyon, Gholson J.; Yu, Dongmei; McGrath, Lauren M.; McMahon, William M.; Lee, Paul C.; Delucchi, Kevin L.; Scharf, Jeremiah M.

2016-01-01

Objective: To identify heritable symptom-based subtypes of Tourette syndrome (TS). Methods: Forty-nine motor and phonic tics were examined in 3,494 individuals (1,191 TS probands and 2,303 first-degree relatives). Item-level exploratory factor and latent class analyses (LCA) were used to identify tic-based subtypes. Heritabilities of the subtypes were estimated, and associations with clinical characteristics were examined. Results: A 6-factor exploratory factor analysis model provided the best fit, which paralleled the somatotopic representation of the basal ganglia, distinguished simple from complex tics, and separated out socially disinhibited and compulsive tics. The 5-class LCA model best distinguished among the following groups: unaffected, simple tics, intermediate tics without social disinhibition, intermediate with social disinhibition, and high rates of all tic types. Across models, a phenotype characterized by high rates of social disinhibition emerged. This phenotype was associated with increased odds of comorbid psychiatric disorders, in particular, obsessive-compulsive disorder and attention-deficit/hyperactivity disorder, earlier age at TS onset, and increased tic severity. The heritability estimate for this phenotype based on the LCA was 0.53 (SE 0.08, p 1.7 × 10−18). Conclusions: Expanding on previous modeling approaches, a series of TS-related phenotypes, including one characterized by high rates of social disinhibition, were identified. These phenotypes were highly heritable and may reflect underlying biological networks more accurately than traditional diagnoses, thus potentially aiding future genetic, imaging, and treatment studies. PMID:27371487

Social disinhibition is a heritable subphenotype of tics in Tourette syndrome.

PubMed

Hirschtritt, Matthew E; Darrow, Sabrina M; Illmann, Cornelia; Osiecki, Lisa; Grados, Marco; Sandor, Paul; Dion, Yves; King, Robert A; Pauls, David L; Budman, Cathy L; Cath, Danielle C; Greenberg, Erica; Lyon, Gholson J; Yu, Dongmei; McGrath, Lauren M; McMahon, William M; Lee, Paul C; Delucchi, Kevin L; Scharf, Jeremiah M; Mathews, Carol A

2016-08-02

To identify heritable symptom-based subtypes of Tourette syndrome (TS). Forty-nine motor and phonic tics were examined in 3,494 individuals (1,191 TS probands and 2,303 first-degree relatives). Item-level exploratory factor and latent class analyses (LCA) were used to identify tic-based subtypes. Heritabilities of the subtypes were estimated, and associations with clinical characteristics were examined. A 6-factor exploratory factor analysis model provided the best fit, which paralleled the somatotopic representation of the basal ganglia, distinguished simple from complex tics, and separated out socially disinhibited and compulsive tics. The 5-class LCA model best distinguished among the following groups: unaffected, simple tics, intermediate tics without social disinhibition, intermediate with social disinhibition, and high rates of all tic types. Across models, a phenotype characterized by high rates of social disinhibition emerged. This phenotype was associated with increased odds of comorbid psychiatric disorders, in particular, obsessive-compulsive disorder and attention-deficit/hyperactivity disorder, earlier age at TS onset, and increased tic severity. The heritability estimate for this phenotype based on the LCA was 0.53 (SE 0.08, p 1.7 × 10(-18)). Expanding on previous modeling approaches, a series of TS-related phenotypes, including one characterized by high rates of social disinhibition, were identified. These phenotypes were highly heritable and may reflect underlying biological networks more accurately than traditional diagnoses, thus potentially aiding future genetic, imaging, and treatment studies. © 2016 American Academy of Neurology.

Patterns of productive activity engagement among older adults in urban China.

PubMed

Liu, Huiying; Lou, Wei Qun

2016-12-01

This study aims to identify patterns of productive activity engagement among older adults in urban China. Once patterns are identified, we further explore how a set of individual characteristics is associated with these patterns. Using data from the 2011 baseline survey of the China Health and Retirement Longitudinal Study (CHARLS), we performed a latent class analysis (LCA) on a national representative sample of adults aged 60 years and over ( N  = 3019). A specified range of productive activity indicators that fit the context of urban China was used for performing LCA (including working, grandchildren's care, parental care, spousal care, informal helping, and formal volunteering). A multinomial logistic regression was used to assess whether individual characteristics are associated with the identified patterns. The results indicated that a four-class model fit the data well, with the interpretable set of classes: spouse carer (51.2 %), working grandparents (21.7 %), multifaceted contributor (16.6 %), and light-engaged volunteer (10.5 %). Age, gender, education, number of children, proximity with the nearest child, household composition and functional status contributed to differentiating these classes. This study captured the reality of productive engagement among older adults by drawing attention to how multiple productive activities intersect in later-life stages. Our findings have implications for policy-makers, health care practitioners, and community advocates to develop programs that facilitate this aging population in assuming meaningful productive activities.

Latent class analysis of eating and impulsive behavioral symptoms in Taiwanese women with bulimia nervosa.

PubMed

Tseng, Mei-Chih Meg; Hu, Fu-Chang

2012-01-01

The implications of impulsivity in its relationship with binge-eating or purging behaviors remain unclear. This study examined the patterns of eating behaviors and co-morbid impulsive behaviors in individuals with bulimia nervosa n optimally homogeneous classes using latent class analysis (LCA). All participants (n=180) were asked to complete a series of self-reported inventories of impulsive behaviors and other psychological measures. Information regarding the lifetime presence of symptoms of eating disorder was assessed by clinical interviews. LCA was conducted using eating disorder symptoms, impulsive behaviors, and the number of purging methods. Three latent classes of bulimic women were identified. These were women who exhibited relatively higher rates of purging, symptoms of impulsive behavior, and multiple purging methods (17.8%), women who used no more than one purging method with a low occurrence of impulsive behavior (41.7%), and women who showed higher rates of purging behaviors and the use of multiple purging methods with a low rate of impulsive behavior (41.7%). The impulsive sub-group had comparable severity of eating-related measures, frequency of binge-eating, and higher levels of general psychopathology than that of the other two sub-groups. This study provides empirical support for the existence of an impulsive subgroup with distinctive features among a non-Western group of BN patients. This study also suggests that mechanisms other than impulse dysregulation may exist for the development of binge-eating and purging behaviors in bulimia nervosa patients, or the mechanisms contributing to binge-eating and impulsive behaviors may be different. Copyright © 2011 Elsevier Inc. All rights reserved.

The Brief Illness Perceptions Questionnaire identifies 3 classes of people seeking rehabilitation for mechanical neck pain.

PubMed

Walton, David M; Lefebvre, Andy; Reynolds, Darcy

2015-06-01

Illness representations pertain to the ways in which an individual constructs and understands the experience of a health condition. The Brief Illness Perceptions Questionnaire (BIPQ) comprises 9 items intended to capture the key components of the Illness Representations Model. The purpose of this paper was to explore the utility of the BIPQ for evaluating and classifying uncomplicated mechanical neck pain in the rehabilitation setting. A convenience sample of 198 subjects presenting to physiotherapy for neck pain problems were used in this study. In the first step, 183 subjects completed the BIPQ and a series of related cognitive measures. Latent class analysis (LCA) was used to explore the number of identifiable classes amongst the sample based on BIPQ response patterns. A regression equation was created to facilitate classification. In the second step, an independent sample of 15 subjects were classified using the equation established in step 1, and they were followed over a 3 month period. The LCA revealed 3 classes of subjects with optimal fit statistics: mildly affected, moderately affected, and severely affected. Inter-group comparisons of the secondary cognitive measures supported these labels. Classification accuracy of a regression equation was high (94.5%). Applying the equation to the independent longitudinal sample revealed that it functioned equally well and that the classes may have prognostic value. The BIPQ may be a useful clinical tool for classification of neck pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Factors associated with patterns of mobile technology use among persons who inject drugs.

PubMed

Collins, Kelly M; Armenta, Richard F; Cuevas-Mota, Jazmine; Liu, Lin; Strathdee, Steffanie A; Garfein, Richard S

2016-01-01

New and innovative methods of delivering interventions are needed to further reduce risky behaviors and increase overall health among persons who inject drugs (PWID). Mobile health (mHealth) interventions have potential for reaching PWID; however, little is known about mobile technology use (MTU) in this population. In this study, the authors identify patterns of MTU and identified factors associated with MTU among a cohort of PWID. Data were collected through a longitudinal cohort study examining drug use, risk behaviors, and health status among PWID in San Diego, California. Latent class analysis (LCA) was used to define patterns of MTU (i.e., making voice calls, text messaging, and mobile Internet access). Multinomial logistic regression was then used to identify demographic characteristics, risk behaviors, and health indicators associated with mobile technology use class. In LCA, a 4-class solution fit the data best. Class 1 was defined by low MTU (22%, n = 100); class 2, by PWID who accessed the Internet using a mobile device but did not use voice or text messaging (20%, n = 95); class 3, by primarily voice, text, and connected Internet use (17%, n = 91); and class 4, by high MTU (41%, n = 175). Compared with low MTU, high MTU class members were more likely to be younger, have higher socioeconomic status, sell drugs, and inject methamphetamine daily. The majority of PWID in San Diego use mobile technology for voice, text, and/or Internet access, indicating that rapid uptake of mHealth interventions may be possible in this population. However, low ownership and use of mobile technology among older and/or homeless individuals will need to be considered when implementing mHealth interventions among PWID.

Competing values among criminal justice administrators: The importance of substance abuse treatment.

PubMed

Henderson, Craig E; Taxman, Faye S

2009-08-01

This study applied latent class analysis (LCA) to examine heterogeneity in criminal justice administrators' attitudes toward the importance of substance abuse treatment relative to other programs and services commonly offered in criminal justice settings. The study used data collected from wardens, probation and/or parole administrators, and other justice administrators as part of the National Criminal Justice Treatment Practices survey (NCJTP), and includes both adult criminal and juvenile justice samples. Results of the LCA suggested that administrators fell into four different latent classes: (1) those who place a high importance on substance abuse treatment relative to other programs and services, (2) those who place equal importance on substance abuse treatment and other programs and services, (3) those who value other programs and services moderately more than substance abuse treatment, and (4) those who value other programs and services much more than substance abuse treatment. Latent class membership was in turn associated with the extent to which evidence-based substance abuse treatment practices were being used in the facilities, the region of the country in which the administrator worked, and attitudes toward rehabilitating drug-using offenders. The findings have implications for future research focused on the impact that administrators' attitudes have on service provision as well as the effectiveness of knowledge dissemination and diffusion models.

Competing Values Among Criminal Justice Administrators: The Importance of Substance Abuse Treatment*

PubMed Central

Henderson, Craig E.; Taxman, Faye S.

2009-01-01

This study applied latent class analysis (LCA) to examine heterogeneity in criminal justice administrators’ attitudes toward the importance of substance abuse treatment relative to other programs and services commonly offered in criminal justice settings. The study used data collected from wardens, probation and/or parole administrators, and other justice administrators as part of the National Criminal Justice Treatment Practices survey (NCJTP), and includes both adult criminal and juvenile justice samples. Results of the LCA suggested that administrators fell into four different latent classes: (1) those who place a high importance on substance abuse treatment relative to other programs and services, (2) those who place equal importance on substance abuse treatment and other programs and services, (3) those who value other programs and services moderately more than substance abuse treatment, and (4) those who value other programs and services much more than substance abuse treatment. Latent class membership was in turn associated with the extent to which evidence-based substance abuse treatment practices were being used in the facilities, the region of the country in which the administrator worked, and attitudes toward rehabilitating drug-using offenders. The findings have implications for future research focused on the impact that administrators’ attitudes have on service provision as well as the effectiveness of knowledge dissemination and diffusion models. PMID:19054632

Comparison of Suicide Attempters and Decedents in the U.S. Army: A Latent Class Analysis.

PubMed

Skopp, Nancy A; Smolenski, Derek J; Sheppard, Sean C; Bush, Nigel E; Luxton, David D

2016-08-01

A clearer understanding of risk factors for suicidal behavior among soldiers is of principal importance to military suicide prevention. It is unclear whether soldiers who attempt suicide and those who die by suicide have different patterns of risk factors. As such, preventive efforts aimed toward reducing suicide attempts and suicides, respectively, may require different strategies. We conducted a latent class analysis (LCA) to examine classes of risk factors among suicide attempters (n = 1,433) and decedents (n = 424). Both groups were represented by three classes: (1) External/Antisocial Risk Factors, (2) Mental Health Risk Factors, and (3) No Pattern. These findings support the conceptualization that military suicide attempters and decedents represent a single population. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Anxiety, bulimia, drug and alcohol addiction, depression, and schizophrenia: what do you think about their aetiology, dangerousness, social distance, and treatment? A latent class analysis approach.

PubMed

Mannarini, Stefania; Boffo, Marilisa

2015-01-01

Mental illness stigma is a serious societal problem and a critical impediment to treatment seeking for mentally ill people. To improve the understanding of mental illness stigma, this study focuses on the simultaneous analysis of people's aetiological beliefs, attitudes (i.e. perceived dangerousness and social distance), and recommended treatments related to several mental disorders by devising an over-arching latent structure that could explain the relations among these variables. Three hundred and sixty university students randomly received an unlabelled vignette depicting one of six mental disorders to be evaluated on the four variables on a Likert-type scale. A one-factor Latent Class Analysis (LCA) model was hypothesized, which comprised the four manifest variables as indicators and the mental disorder as external variable. The main findings were the following: (a) a one-factor LCA model was retrieved; (b) alcohol and drug addictions are the most strongly stigmatized; (c) a realistic opinion about the causes and treatment of schizophrenia, anxiety, bulimia, and depression was associated to lower prejudicial attitudes and social rejection. Beyond the general appraisal of mental illness an individual might have, the results generally point to the acknowledgement of the specific features of different diagnostic categories. The implications of the present results are discussed in the framework of a better understanding of mental illness stigma.

Maternal eating disorder and infant diet. A latent class analysis based on the Norwegian Mother and Child Cohort Study (MoBa)

PubMed Central

Torgersen, Leila; Ystrom, Eivind; Siega-Riz, Anna Maria; Berg, Cecilie Knoph; Zerwas, Stephanie; Reichborn-Kjennerud, Ted; Bulik, Cynthia M.

2015-01-01

Knowledge of infant diet and feeding practices among children of mothers with eating disorders is essential to promote healthy eating in these children. This study compared the dietary patterns of 6-month-old children of mothers with anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorder not otherwise specified - purging subtype, to the diet of children of mothers with no eating disorders. The study was based on 53,879 mothers in the Norwegian Mother and Child Cohort Study (MoBa). Latent class analysis (LCA) was used to identify discrete latent classes of infant diet based on the mothers’ responses to questions about 16 food items. LCA identified five classes, characterized by primarily homemade vegetarian food (4% of the infants in the sample), homemade traditional food (8%), commercial infant cereals (35%), commercial jarred baby food (39%), and a mix of all food groups (11%). We then estimated the association between the different latent dietary classes and maternal eating disorders using a multinomial logistic regression model. Infants of mothers with bulimia nervosa had a lower probability of being in the homemade traditional food class compared to the commercial jarred baby food class, than the referent without an eating disorder (O.R. 0.59; 95% CI 0.36–0.99). Infants of mothers with binge eating disorder had a lower probability of being in the homemade vegetarian class compared to the commercial jarred baby food class, than the referent (O.R. 0.77; 95% CI 0.60–0.99), but only before controlling for relevant confounders. Anorexia nervosa and eating disorder not otherwise specified-purging subtype were not statistically significant associated with any of the dietary classes. These results suggest that in the general population, maternal eating disorders may to some extent influence the child’s diet as early as 6 months after birth; however, the extent to which these differences influence child health and development remain an area for further inquiry. PMID:25453594

Are all risks equal? Early experiences of poverty-related risk and children's functioning.

PubMed

Roy, Amanda L; Raver, C Cybele

2014-06-01

Using cumulative risk and latent class analysis (LCA) models, we examined how exposure to deep poverty (income-to-needs ratio <0.50) and 4 poverty-related risks (i.e., single-parent household, residential crowding, caregiver depression, and multiple life stressors) in preschool is related to children's future difficulty in school in a longitudinal sample of 602 Head Start-enrolled, low-income families. Results from the LCA revealed 4 risk profiles: low risk, deep poverty and single, single and stressed, and deep poverty and crowded household. Tests of measurement invariance across racial/ethnic groups established that, although patterns of risk are similar across groups (i.e., risks covary in the same way), the prevalence of risk profiles differs. African American families were overrepresented in the "deep poverty and single" profile while Latino and White families were overrepresented in the "deep poverty and crowded" profile. Finally, children's third grade functioning in 3 domains (i.e., academic performance, behavior problems, and self-regulatory skills) was predicted using a cumulative risk index and LCA-identified risk profiles. Both approaches demonstrated that children who experienced higher levels of risk in preschool had worse school performance than children with low levels of risk. However, LCA also revealed that children who experienced "single and stressed" family settings had more behavior problems than low-risk children while children who experienced "deep poverty and crowded" family settings had worse academic performance. The results indicate that all risks are not equal for children's development and highlight the utility of LCA for tailoring intervention efforts to best meet the needs of target populations. PsycINFO Database Record (c) 2014 APA, all rights reserved

Are All Risks Equal? Early Experiences of Poverty-Related Risk and Children’s Functioning

PubMed Central

Roy, Amanda L.; Raver, C. Cybele

2014-01-01

Using cumulative risk and latent class analysis (LCA) models, this research examines how exposure to deep poverty (income-to-needs ratio <.50) and four poverty-related risks (single-parent household, residential crowding, caregiver depression, and multiple life stressors) in preschool is related to children’s future difficulty in school in a longitudinal sample of 602 Head-Start enrolled, low-income families. Results from the LCA revealed four risk profiles: low risk, deep poverty and single, single and stressed, and deep poverty and crowded household. Tests of measurement invariance across racial/ethnic groups established that although patterns of risk are similar across groups (i.e. risks co-vary in the same way), the prevalence of risk profiles differ. African American families were over-represented in the ‘deep poverty and single’ profile while Latino and White families were over-represented in the ‘deep poverty and crowded’ profile. Finally, children’s third grade functioning in three domains (academic performance, behavior problems, self-regulatory skills) was predicted using a cumulative risk index and LCA identified risk profiles. Both approaches demonstrated that children who experienced higher levels of risk in preschool had worse school performance than children with low levels of risk. However, the LCA also revealed that children who experienced ‘single and stressed’ family settings had more behavior problems than low risk children while children who experienced ‘deep poverty and crowded’ family settings had worse academic performance. The results indicate that all risks are not equal for children’s development and highlight the utility of LCA for tailoring intervention efforts to best meet the needs of target populations. PMID:24749652

Area of Concern: a new paradigm in life cycle assessment for ...

EPA Pesticide Factsheets

Purpose: As a class of environmental metrics, footprints have been poorly defined, have shared an unclear relationship to life cycle assessment (LCA), and the variety of approaches to quantification have sometimes resulted in confusing and contradictory messages in the marketplace. In response, a task force operating under the auspices of the UNEP/SETAC Life Cycle Initiative project on environmental life cycle impact assessment (LCIA) has been working to develop generic guidance for developers of footprint metrics. The purpose of this paper is to introduce a universal footprint definition and related terminology as well as to discuss modelling implications.MethodsThe task force has worked from the perspective that footprints should be based on LCA methodology, underpinned by the same data systems and models as used in LCA. However, there are important differences in purpose and orientation relative to LCA impact category indicators. Footprints have a primary orientation toward society and nontechnical stakeholders. They are also typically of narrow scope, having the purpose of reporting only in relation to specific topics. In comparison, LCA has a primary orientation toward stakeholders interested in comprehensive evaluation of overall environmental performance and trade-offs among impact categories. These differences create tension between footprints, the existing LCIA framework based on the area of protection paradigm and the core LCA standards ISO14040/44.Res

Molecular genetics of Leber congenital amaurosis in Chinese: New data from 66 probands and mutation overview of 159 probands.

PubMed

Xu, Yan; Xiao, Xueshan; Li, Shiqiang; Jia, Xiaoyun; Xin, Wei; Wang, Panfeng; Sun, Wenmin; Huang, Li; Guo, Xiangming; Zhang, Qingjiong

2016-08-01

Leber congenital amaurosis (LCA) is the most severe form of inherited retinal dystrophy. We have previously performed a mutational analysis of the known LCA-associated genes in probands with LCA by both Sanger and whole exome sequencing. In this study, whole exome sequencing was carried out on 66 new probabds with LCA. In conjunction with these data, the present study provides a comprehensive analysis of the spectrum and frequency of all known genes associated with retinal dystrophy in a total of 159 Chinese probands with LCA. The known genes responsible for all forms hereditary retinal dystrophy were included based on information from RetNet. The candidate variants were filtered by bioinformatics analysis and confirmed by Sanger sequencing. Potentially causative mutations were further validated in available family members. Overall, a total of 118 putative pathogenic mutations from 23 genes were identified in 56.6% (90/159) of probands. These mutations were harbored in 13 LCA-associated genes and in ten genes related to other forms of retinal dystrophy. The most frequently mutated gene in probands with LCA was GUCY2D (10.7%, 17/159). A series of mutational analyses suggests that all known genes associated with retinal dystrophy account for 56.6% of Chinese patients with LCA. A comprehensive molecular genetic analysis of Chinese patients with LCA provides an overview of the spectrum and frequency of ethno-specific mutations of all known genes, as well as indications about other unknown genes in the remaining probands who lacked identified mutations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Investigations of Potential Phenotypes of Foot Osteoarthritis: Cross‐Sectional Analysis From the Clinical Assessment Study of the Foot

PubMed Central

Marshall, Michelle; Thomas, Martin J.; Menz, Hylton B.; Myers, Helen L.; Thomas, Elaine; Downes, Thomas; Peat, George; Roddy, Edward

2016-01-01

Objective To investigate the existence of distinct foot osteoarthritis (OA) phenotypes based on pattern of joint involvement and comparative symptom and risk profiles. Methods Participants ages ≥50 years reporting foot pain in the previous year were drawn from a population‐based cohort. Radiographs were scored for OA in the first metatarsophalangeal (MTP) joint, first and second cuneometatarsal, navicular first cuneiform, and talonavicular joints according to a published atlas. Chi‐square tests established clustering, and odds ratios (ORs) examined symmetry and pairwise associations of radiographic OA in the feet. Distinct underlying classes of foot OA were investigated by latent class analysis (LCA) and their association with symptoms and risk factors was assessed. Results In 533 participants (mean age 64.9 years, 55.9% female) radiographic OA clustered across both feet (P < 0.001) and was highly symmetrical (adjusted OR 3.0, 95% confidence interval 2.1, 4.2). LCA identified 3 distinct classes of foot OA: no or minimal foot OA (64%), isolated first MTP joint OA (22%), and polyarticular foot OA (15%). After adjustment for age and sex, polyarticular foot OA was associated with nodal OA, increased body mass index, and more pain and functional limitation compared to the other classes. Conclusion Patterning of radiographic foot OA has provided insight into the existence of 2 forms of foot OA: isolated first MTP joint OA and polyarticular foot OA. The symptom and risk factor profiles in individuals with polyarticular foot OA indicate a possible distinctive phenotype of foot OA, but further research is needed to explore the characteristics of isolated first MTP joint and polyarticular foot OA. PMID:26238801

Studying Psychosocial Barriers to Drug Treatment Among Chinese Methamphetamine Users Using A 3-Step Latent Class Analysis.

PubMed

Wang, Jichuan; Kelly, Brian C; Liu, Tieqiao; Hao, Wei

2016-03-01

Given the growth in methamphetamine use in China during the 21st century, we assessed perceived psychosocial barriers to drug treatment among this population. Using a sample of 303 methamphetamine users recruited via Respondent Driven Sampling, we use Latent Class Analysis (LCA) to identify possible distinct latent groups among Chinese methamphetamine users on the basis of their perceptions of psychosocial barriers to drug treatment. After covariates were included to predict latent class membership, the 3-step modeling approach was applied. Our findings indicate that the Chinese methamphetamine using population was heterogeneous on perceptions of drug treatment barriers; four distinct latent classes (subpopulations) were identified--Unsupported Deniers, Deniers, Privacy Anxious, and Low Barriers--and individual characteristics shaped the probability of class membership. Efforts to link Chinese methamphetamine users to treatment may require a multi-faceted approach that attends to differing perceptions about impediments to drug treatment. Copyright © 2015. Published by Elsevier Inc.

Patterns of Adolescent Bullying Behaviors: Physical, Verbal, Exclusion, Rumor, and Cyber

PubMed Central

Wang, Jing; Iannotti, Ronald J.; Luk, Jeremy W.

2012-01-01

Patterns of engagement in cyber bullying and four types of traditional bullying were examined using latent class analysis (LCA). Demographic differences and externalizing problems were evaluated across latent class membership. Data were obtained from the 2005–2006 Health Behavior in School-aged Survey and the analytic sample included 7,508 U.S. adolescents in grades 6 through 10. LCA models were tested on physical bullying, verbal bullying, social exclusion, spreading rumors, and cyber bullying behaviors. Three latent classes were identified for each gender: All-Types Bullies (10.5% for boys and 4.0% for girls), Verbal/Social Bullies (29.3% for boys and 29.4% for girls), and a Non-Involved class (60.2% for boys and 66.6% for girls). Boys were more likely to be All-Types Bullies than girls. The prevalence rates of All-Types and Verbal/Social Bullies peaked during grades 6 to 8 and grades 7 & 8, respectively. Pairwise comparisons across the three latent classes on externalizing problems were conducted. Overall, the All-Types Bullies were at highest risk of using substances and carrying weapons, the Non-Involved were at lowest risk, and the Verbal/Social Bullies were in the middle. Results also suggest that most cyber bullies belong to a group of highly aggressive adolescents who conduct all types of bullying. This finding does not only improve our understanding of the relation between cyber bullying and traditional bullying, but it also suggests that prevention and intervention efforts could target cyber bullies as a high-risk group for elevated externalizing problems. PMID:22710019

Clustering of unhealthy behaviors in the aerobics center longitudinal study.

PubMed

Héroux, Mariane; Janssen, Ian; Lee, Duck-chul; Sui, Xuemei; Hebert, James R; Blair, Steven N

2012-04-01

Clustering of unhealthy behaviors has been reported in previous studies; however the link with all-cause mortality and differences between those with and without chronic disease requires further investigation. To observe the clustering effects of unhealthy diet, fitness, smoking, and excessive alcohol consumption in adults with and without chronic disease and to assess all-cause mortality risk according to the clustering of unhealthy behaviors. Participants were 13,621 adults (aged 20-84) from the Aerobics Center Longitudinal Study. Four health behaviors were observed (diet, fitness, smoking, and drinking). Baseline characteristics of the study population and bivariate relations between pairs of the health behaviors were evaluated separately for those with and without chronic disease using cross-tabulation and a chi-square test. The odds of partaking in unhealthy behaviors were also calculated. Latent class analysis (LCA) was used to assess clustering. Cox regression was used to assess the relationship between the behaviors and mortality. The four health behaviors were related to each other. LCA results suggested that two classes existed. Participants in class 1 had a higher probability of partaking in each of the four unhealthy behaviors than participants in class 2. No differences in health behavior clustering were found between participants with and without chronic disease. Mortality risk increased relative to the number of unhealthy behaviors participants engaged in. Unhealthy behaviors cluster together irrespective of chronic disease status. Such findings suggest that multi-behavioral intervention strategies can be similar in those with and without chronic disease.

A Latent Class Analysis of Maternal Responsiveness and Autonomy-Granting in Early Adolescence: Prediction to Later Adolescent Sexual Risk-Taking

PubMed Central

Lanza, H. Isabella; Huang, David Y. C.; Murphy, Debra A.; Hser, Yih-Ing

2013-01-01

The present study sought to extend empirical inquiry related to the role of parenting on adolescent sexual risk-taking by using latent class analysis (LCA) to identify patterns of adolescent-reported mother responsiveness and autonomy-granting in early adolescence and examine associations with sexual risk-taking in mid- and late-adolescence. Utilizing a sample of 12- to 14-year-old adolescents (N = 4,743) from the 1997 National Longitudinal Survey of Youth (NLSY97), results identified a four-class model of maternal responsiveness and autonomy-granting: low responsiveness/high autonomy-granting, moderate responsiveness/moderate autonomy-granting, high responsiveness/low autonomy-granting, high responsiveness/moderate autonomy-granting. Membership in the low responsiveness/high autonomy-granting class predicted greater sexual risk-taking in mid- and late-adolescence compared to all other classes, and membership in the high responsiveness/ moderate autonomy-granting class predicted lower sexual risk-taking. Gender and ethnic differences in responsiveness and autonomy-granting class membership were also found, potentially informing gender and ethnic disparities of adolescent sexual risk-taking. PMID:23828712

Complex Drug Use Patterns and Associated HIV Transmission Risk Behaviors in an Internet Sample of U.S. Men Who Have Sex with Men

PubMed Central

Yu, Gary; Wall, Melanie M.; Chiasson, Mary Ann; Hirshfield, Sabina

2015-01-01

Although the relationship between drug use and HIV risk among men who have sex with men (MSM) is well described, relatively few studies have employed empirical methods to assess underlying classes of drug use that may better predict the risk of HIV or sexually transmitted infections (STIs) among MSM. The aim of this study was to determinewhether latent class analysis (LCA) would identify underlying drug classes reported prior to sex, as well as predict unprotected anal intercourse (UAI) in the last sexual encounter among MSM. From 2004 to 2005, an anonymous online survey was conducted among 8,717 sexually active MSM recruited from gay-affiliated U.S. websites. LCA clustered participants into six distinct drug use classes based on the specific types and number of drugs used: (1) low/no drug use, (2) recreational drug use, (3) poppers with prescription erectile dysfunction (ED) drug use, (4) poppers with both prescription and non-prescription ED drug use, (5) recreational, club, and ED drug use, and (6) high polydrug use. Compared with men in Class 1, men in the highest drug use class were 4.84 times more likely to report UAI in their last sexual encounter and 3.78 times more likely to report an STI in the past year (both ps<.001). Younger MSM aged 18–29 were significantly more likely to report an STI than men aged 50 and above (p<.001). There is a need to better understand the complex relationship between a diverse set of drugs used among MSM and how polydrug use impacts sexual negotiation over time. PMID:25104104

Experience by children and adolescents of more than one type of maltreatment: Association of different classes of maltreatment profiles with clinical outcome variables.

PubMed

Witt, Andreas; Münzer, Annika; Ganser, Helene G; Fegert, Jörg M; Goldbeck, Lutz; Plener, Paul L

2016-07-01

Most victims of child abuse have experienced more than one type of maltreatment, yet there is a lack of understanding of the impact of specific combinations of types of maltreatment. This study aimed to identify meaningful classes of maltreatment profiles and to associate them with short-term clinical outcomes. A total of 358 German children and adolescents aged 4-17 with a known history of child maltreatment were included in the study. Through interviews and questionnaires, information was obtained from participants and their primary caregivers on history of maltreatment, sociodemographics, psychopathology, level of psychosocial functioning, and health-related quality of life. Types of abuse were categorized into six major groups: sexual abuse in general, sexual abuse with penetration, physical abuse, emotional abuse, neglect, and exposure to domestic violence. A latent class analysis (LCA) was performed to determine distinct multi-type maltreatment profiles, which were then assessed for their associations with the sociodemographic and clinical outcome variables. The LCA revealed that participants could be categorized into three meaningful classes according to history of maltreatment: (1) experience of multiple types of maltreatment excluding sexual abuse (63.1%), (2) experience of multiple types of maltreatment including sexual abuse (26.5%), and (3) experience of predominantly sexual abuse (10.3%). Members of Class 2 showed significantly worse short-term outcomes on psychopathology, level of functioning, and quality of life compared to the other classes. Three distinct profiles of multiple types of maltreatment were empirically identified in this sample. Exposure to multiple types of abuse was associated with poorer outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Patterns of diet-related practices and prevalence of gastro-esophageal reflux disease.

PubMed

Esmaillzadeh, A; Keshteli, A H; Feizi, A; Zaribaf, F; Feinle-Bisset, C; Adibi, P

2013-10-01

No studies have evaluated associations between patterns of diet-related practices as determined by latent class analysis (LCA) and gastro-esophageal reflux disease (GERD). We aimed to assess this relationship in a large sample of Iranian adults. In a cross-sectional study in 4763 adults, diet-related practices were assessed in four domains, 'meal pattern', 'eating rate', 'intra-meal fluid intake', and 'meal-to-sleep interval', using a pretested questionnaire. LCA was applied to identify classes of diet-related practices. We defined GERD as the presence of heartburn sometimes, often or always. The prevalence of GERD in the study population was 23.5% (n = 1120). We identified two distinct classes of meal patterns: 'regular' and 'irregular', three classes of eating rates: 'moderate', 'moderate-to-slow', and 'moderate-to-fast', two major classes of fluid ingestion with meals: 'moderate' and 'much intra-meal drinking', and two classes regarding the interval between meals and sleeping: 'short' and 'long meal-to-sleep' interval. After adjustment for potential confounders, subjects with 'irregular meal pattern' had higher odds of GERD compared with subjects with 'regular meal pattern' (OR: 1.21; 1.00-1.46). However, when taking into account BMI, the association disappeared. 'Long meal-to-sleep interval' was inversely associated with GERD compared with 'short meal-to-sleep interval' (OR: 0.73; 95% CI: 0.57-0.95). 'Eating rate' and 'intra-meal fluid intake' were not significantly associated with GERD. Our data suggest certain associations between dietary patterns and GERD. These findings warrant evaluation in prospective studies to establish the potential value of modifications in dietary behaviors for the management of GERD. © 2013 John Wiley & Sons Ltd.

The Structure of Co-Occurring Bullying Experiences and Associations with Suicidal Behaviors in Korean Adolescents.

PubMed

Roh, Beop-Rae; Yoon, Yoewon; Kwon, Ahye; Oh, Seunga; Lee, Soyoung Irene; Ha, Kyunghee; Shin, Yun Mi; Song, Jungeun; Park, Eun Jin; Yoo, Heejung; Hong, Hyun Ju

2015-01-01

This study had two main goals: to examine the structure of co-occurring peer bullying experiences among adolescents in South Korea from the perspective of victims and to determine the effects of bullying on suicidal behavior, including suicidal ideation and suicide attempts, among adolescents. This study used data gathered from 4,410 treatment-seeking adolescents at their initial visits to 31 local mental health centers in Gyeonggi Province, South Korea. The structure of peer bullying was examined using latent class analysis (LCA) to classify participants' relevant experiences. Then, a binomial logistic regression adjusted by propensity scores was conducted to identify relationships between experiences of being bullied and suicidal behaviors. The LCA of experiences with bullying revealed two distinct classes of bullying: physical and non-physical. Adolescents who experienced physical bullying were 3.05 times more likely to attempt suicide than those who were not bullied. Victims of (non-physical) cyber bullying were 2.94 times more likely to attempt suicide than were those who were not bullied. Both physical and non-physical bullying were associated with suicide attempts, with similar effect sizes. Schools and mental health professionals should be more attentive than they currently are to non-physical bullying.

The categorisation of dysthymic disorder: can its constituents be meaningfully apportioned?

PubMed

Rhebergen, Didi; Graham, Rebecca; Hadzi-Pavlovic, Dusan; Stek, Max; Friend, Paul; Barrett, Melissa; Parker, Gordon

2012-12-20

Since its introduction in DSM-III, the validity of dysthymia has been debated. Our objective is to further examine the concept of dysthymia in an outpatient sample, and explore whether its constituents can be meaningfully apportioned. 318 patients attending the Black Dog Institute Depression Clinic were assessed by the Mini-International Neuropsychiatric Interview, and completed several self-report measures, in addition to a clinical assessment by an Institute psychiatrist. The characteristics of patients with major depressive disorder (MDD), dysthymic disorder and double depression were examined. Latent Class Analysis (LCA) and Latent Profile Analysis (LPA) were then conducted with the aim of detecting distinct classes based on depressive symptomatology and personality domains, respectively. Finally, clinicians' formulations of the study patients were examined. Depression groups mainly differed on parameters of severity. Although LCA and LPA analyses indicated the presence of distinct classes, these only moderately correlated with the MINI-diagnosed groups. Finally, there was evidence for considerable heterogeneity within clinicians' formulations of dysthymia. Inadequate sample numbers for various measures limited the power of the LPA and our sample was weighted to patients with a more severe depressive condition which may affect the detection of a distinct 'dysthymic' personality profile. Despite employing a variety of techniques, we were unable to obtain a clear homogeneous picture of dysthymia. Rather, there was evidence for a distinct heterogeneity in clinician-derived diagnoses. These findings allude to the questionable discriminant validity of dysthymia and may encourage future research and discussion on this important topic. Copyright © 2012 Elsevier B.V. All rights reserved.

Cross-Informant Agreement on Child and Adolescent Withdrawn Behavior: A Latent Class Approach

ERIC Educational Resources Information Center

Rubin, David H.; Althoff, Robert R.; Walkup, John T.; Hudziak, James J.

2013-01-01

Withdrawn behavior (WB) relates to many developmental outcomes, including pervasive developmental disorders, anxiety, depression, psychosis, personality disorders and suicide. No study has compared the latent profiles of different informants' reports on WB. This study uses multi-informant latent class analyses (LCA) of the child behavior checklist…

Depressive symptoms among adolescents and older adults in Mexico City.

PubMed

Sánchez-García, Sergio; García-Peña, Carmen; González-Forteza, Catalina; Jiménez-Tapia, Alberto; Gallo, Joseph J; Wagner, Fernando A

2014-06-01

Determine the structure of depressive symptoms among adolescents and older adults through the person-centered approach of latent class analysis (LCA). The study is based on data from two independent samples collected in Mexico City (2,444 adolescents and 2,223 older adults) which included the revised version of the CES-D. The presence or absence of depressed mood (dysphoria), diminished pleasure (anhedonia), drastic change in weight, sleep problems, thinking and concentration difficulties, excessive or inappropriate guilt, fatigue, psychomotor agitation/retardation, and suicide ideation were used in LCA to determine the structure of depressive symptoms for adolescents and older adults. Adolescents reported higher excessive or inappropriate guilt compared to older adults, while older adults had higher proportions of anhedonia, sleep problems, fatigue, and psychomotor agitation/retardation. Similar proportions were found in other symptoms. The LCA analysis showed the best fit with four latent classes (LC): LC 1, "symptoms suggestive of major depressive episode (MDE)" with prevalence of 5.9 % (n = 144) and 10.3 % (n = 230) among adolescents and older adults, respectively; LC 2, "probable MDE symptoms" 18.2 % (n = 446) and 23.0 % (n = 512); LC 3, "possible MDE" 27.7 % (n = 676) and 21.8 % (n = 485); LC 4, "without significant depressive symptoms" 48.2 % (n = 1,178) and 44.8 % (n = 996). The differences in item thresholds between the two groups (adolescents vs. older adults) were statistically significant (Wald test = 255.684, df = 1, p < 0.001). This study documented important similarities and differences in the structure of depressive symptoms between adolescents and older adults that merit acknowledgment, further study, and consideration of their potential clinical and public health implications.

Chronic fatigue syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands.

PubMed

Collin, Simon M; Nikolaus, Stephanie; Heron, Jon; Knoop, Hans; White, Peter D; Crawley, Esther

2016-02-01

Studies have provided evidence of heterogeneity within chronic fatigue syndrome (CFS), but few have used data from large cohorts of CFS patients or replication samples. 29 UK secondary-care CFS services recorded the presence/absence of 12 CFS-related symptoms; 8 of these symptoms were recorded by a Dutch tertiary service. Latent Class Analysis (LCA) was used to assign symptom profiles (phenotypes). Regression models were fitted with phenotype as outcome (in relation to age, sex, BMI, duration of illness) and exposure (in relation to comorbidities and patient-reported measures). Data were available for 7041 UK and 1392 Dutch patients. Almost all patients in both cohorts presented with post-exertional malaise, cognitive dysfunction and disturbed/unrefreshing sleep, and these 3 symptoms were excluded from LCA. In UK patients, six phenotypes emerged: 'full' polysymptomatic (median 8, IQR 7-9 symptoms) 32.8%; 'pain-only' (muscle/joint) 20.3%; 'sore throat/painful lymph node' 4.5%; and 'oligosymptomatic' (median 1, IQR 0-2 symptoms) 4.7%. Two 'partial' polysymptomatic phenotypes were similar to the 'full' phenotype, bar absence of dizziness/nausea/palpitations (21.4%) or sore throat/painful lymph nodes (16.3%). Women and patients with longer duration of illness were more likely to be polysymptomatic. Polysymptomatic patients had more severe illness and more comorbidities. LCA restricted to 5 symptoms recorded in both cohorts indicated 3 classes (polysymptomatic, oligosymptomatic, pain-only), which were replicated in Dutch data. Adults with CFS may have one of 6 symptom-based phenotypes associated with sex, duration and severity of illness, and comorbidity. Future research needs to determine whether phenotypes predict treatment outcomes, and require different treatments. Copyright © 2015 Elsevier Inc. All rights reserved.

Patterns of adolescent bullying behaviors: physical, verbal, exclusion, rumor, and cyber.

PubMed

Wang, Jing; Iannotti, Ronald J; Luk, Jeremy W

2012-08-01

Patterns of engagement in cyber bullying and four types of traditional bullying were examined using latent class analysis (LCA). Demographic differences and externalizing problems were evaluated across latent class membership. Data were obtained from the 2005-2006 Health Behavior in School-aged Survey and the analytic sample included 7,508 U.S. adolescents in grades 6 through 10. LCA models were tested on physical bullying, verbal bullying, social exclusion, spreading rumors, and cyber bullying behaviors. Three latent classes were identified for each gender: All-Types Bullies (10.5% for boys and 4.0% for girls), Verbal/Social Bullies (29.3% for boys and 29.4% for girls), and a Non-Involved class (60.2% for boys and 66.6% for girls). Boys were more likely to be All-Types Bullies than girls. The prevalence rates of All-Types and Verbal/Social Bullies peaked during grades 6 to 8 and grades 7 and 8, respectively. Pairwise comparisons across the three latent classes on externalizing problems were conducted. Overall, the All-Types Bullies were at highest risk of using substances and carrying weapons, the Non-Involved were at lowest risk, and the Verbal/Social Bullies were in the middle. Results also suggest that most cyber bullies belong to a group of highly aggressive adolescents who conduct all types of bullying. This finding does not only improve our understanding of the relation between cyber bullying and traditional bullying, but it also suggests that prevention and intervention efforts could target cyber bullies as a high-risk group for elevated externalizing problems. Copyright © 2012 Society for the Study of School Psychology. All rights reserved.

Associations among personal care product use patterns and exogenous hormone use in the NIEHS Sister Study.

PubMed

Taylor, Kyla W; Baird, Donna D; Herring, Amy H; Engel, Lawrence S; Nichols, Hazel B; Sandler, Dale P; Troester, Melissa A

2017-09-01

It is hypothesized that certain chemicals in personal care products may alter the risk of adverse health outcomes. The primary aim of this study was to use a data-centered approach to classify complex patterns of exposure to personal care products and to understand how these patterns vary according to use of exogenous hormone exposures, oral contraceptives (OCs) and post-menopausal hormone therapy (HT). The NIEHS Sister Study is a prospective cohort study of 50,884 US women. Limiting the sample to non-Hispanic blacks and whites (N=47,019), latent class analysis (LCA) was used to identify groups of individuals with similar patterns of personal care product use based on responses to 48 survey questions. Personal care products were categorized into three product types (beauty, hair, and skincare products) and separate latent classes were constructed for each type. Adjusted prevalence differences (PD) were calculated to estimate the association between exogenous hormone use, as measured by ever/never OC or HT use, and patterns of personal care product use. LCA reduced data dimensionality by grouping of individuals with similar patterns of personal care product use into mutually exclusive latent classes (three latent classes for beauty product use, three for hair, and four for skin care. There were strong differences in personal care usage by race, particularly for haircare products. For both blacks and whites, exogenous hormone exposures were associated with higher levels of product use, especially beauty and skincare products. Relative to individual product use questions, latent class variables capture complex patterns of personal care product usage. These patterns differed by race and were associated with ever OC and HT use. Future studies should consider personal care product exposures with other exogenous exposures when modeling health risks.

Associations among personal care product use patterns and exogenous hormone use in the NIEHS Sister Study

PubMed Central

Taylor, Kyla W.; Baird, Donna D.; Herring, Amy H.; Engel, Lawrence S.; Nichols, Hazel B.; Sandler, Dale P.; Troester, Melissa A.

2017-01-01

It is hypothesized that certain chemicals in personal care products may alter the risk of adverse health outcomes. The primary aim of this study was to use a data-centered approach to classify complex patterns of exposure to personal care products and to understand how these patterns vary according to use of exogenous hormone exposures, oral contraceptives (OCs) and post-menopausal hormone therapy (HT). The NIEHS Sister Study is a prospective cohort study of 50,884 US women. Limiting the sample to non-Hispanic blacks and whites (N = 47,019), latent class analysis (LCA) was used to identify groups of individuals with similar patterns of personal care product use based on responses to 48 survey questions. Personal care products were categorized into three product types (beauty, hair, and skincare products) and separate latent classes were constructed for each type. Adjusted prevalence differences (PD) were calculated to estimate the association between exogenous hormone use, as measured by ever/never OC or HT use, and patterns of personal care product use. LCA reduced data dimensionality by grouping of individuals with similar patterns of personal care product use into mutually exclusive latent classes (three latent classes for beauty product use, three for hair, and four for skin care. There were strong differences in personal care usage by race, particularly for haircare products. For both blacks and whites, exogenous hormone exposures were associated with higher levels of product use, especially beauty and skincare products. Relative to individual product use questions, latent class variables capture complex patterns of personal care product usage. These patterns differed by race and were associated with ever OC and HT use. Future studies should consider personal care product exposures with other exogenous exposures when modeling health risks. PMID:28120835

Catalytic Properties of Botulinum Neurotoxins Subtypes A3 and A4

PubMed Central

Henkel, James S.; Jacobson, Mark; Tepp, William; Pier, Christina; Johnson, Eric A.; Barbieri, Joseph T.

2009-01-01

Botulinum toxins (BoNT) are zinc proteases (serotypes A-G) which cause flaccid paralysis through the cleavage of SNARE proteins within motor neurons. BoNT/A was originally organized into two subtypes: BoNT/A1 and BoNT/A2, which are ~ 95 % homologous and possess similar catalytic activities. Subsequently, two additional subtypes were identified; BoNT/A3 (Loch Maree), and BoNT/A4 (657Ba), which have 81 and 88% homology with BoNT/A1, respectively. Alignment studies predicted that BoNT/A3 and BoNT/A4 were sufficiently different to BoNT/A1 to affect SNAP25 binding and cleavage. Recombinant Light Chain (LC) of BoNT/A3 (LC/A3) and BoNT/A4 (LC/A4) were subjected to biochemical analysis. LC/A3 cleaved SNAP25 at 50% the rate of LC/A1, but cleaved SNAPtide® at a faster rate than LC/A1, while LC/A4 cleaved SNAP25 and SNAPtide® at slower rates than LC/A1. LC/A3 and LC/A4 had similar Kms for SNAP25 relative to LC/A1, while the kcat for LC/A4 was 10- fold slower than LC/A1, suggesting a defect in substrate cleavage. Neither LC/A3 nor LC/A4 possessed autocatalytic activity, a property of LC/A1 and LC/A2. Thus, the four subtypes of BoNT/A bind SNAP25 with similar affinity but have different catalytic capacities for SNAP25 cleavage, SNAPtide® cleavage, and autocatalysis. The catalytic properties identified among the subtypes of LC/A may influence strategies for the development of small molecule- or peptide- inhibitors as therapies against botulism. PMID:19256469

Complex PTSD as proposed for ICD-11: validation of a new disorder in children and adolescents and their response to Trauma-Focused Cognitive Behavioral Therapy.

PubMed

Sachser, Cedric; Keller, Ferdinand; Goldbeck, Lutz

2017-02-01

To evaluate whether the symptoms of children and adolescents with clinically significant posttraumatic stress symptoms (PTSS) form classes consistent with the diagnostic criteria of complex PTSD (CPTSD) as proposed for the ICD-11, and to relate the emerging classes with treatment outcome of Trauma-Focused Cognitive Behavioral Therapy (TF-CBT). Latent classes analysis (LCA) was used to explore the symptom profiles of the clinical baseline assessment of N = 155 children and adolescents participating in a randomized controlled trial of TF-CBT. The treatment outcomes of patients with posttraumatic stress disorder (PTSD) and of patients with CPTSD were compared by a t-test for depended samples and a repeated-measures ANOVA. The LCA revealed two distinct classes: a PTSD class characterized by elevated core symptoms of PTSD (n = 62) and low symptoms of disturbances in self-organization versus a complex PTSD class with elevated PTSD core symptoms and elevated symptoms of disturbances in self-organization (n = 93). The Group × Time interaction regarding posttraumatic stress symptoms was not significant. Pre-post effect sizes regarding posttraumatic stress symptoms were large for both groups (PTSD: d = 2.81; CPTSD: d = 1.37). For disturbances in self-organization in the CPTSD class, we found medium to large effect sizes (d = 0.40-1.16) after treatment with TF-CBT. The results provide empirical evidence of the ICD-11 CPTSD and PTSD distinction in a clinical sample of children and adolescents. In terms of relative improvement from their respective baseline posttraumatic stress symptoms, patients with PTSD and CPTSD responded equally to TF-CBT; however, those with CPTSD ended treatment with clinically and statistically greater symptoms than those with PTSD. © 2016 Association for Child and Adolescent Mental Health.

Comorbid Anxiety and Depression and Their Impact on Cardiovascular Disease in Type 2 Diabetes: The Fremantle Diabetes Study Phase II.

PubMed

Bruce, David G; Davis, Wendy A; Dragovic, Milan; Davis, Timothy M E; Starkstein, Sergio E

2016-10-01

The aims were to determine whether anxious depression, defined by latent class analysis (LCA), predicts cardiovascular outcomes in type 2 diabetes and to compare the predictive power of anxious depression with Diagnostic & Statistical Manual Versions IV and 5 (DSM-IV/5) categories of depression and generalized anxiety disorder (GAD). Prospective observational study of 1,337 type 2 participants. Baseline assessment with the 9-item Patient Health Questionnaire and the GAD Scale; LCA-defined groups with minor or major anxious depression based on anxiety and depression symptoms. Cox modeling used to compare the independent impact of: (1) LCA anxious depression, (2) DSM-IV/5 depression, (3) GAD on incident cardiovascular events and deaths after 4 years. LCA minor and major anxious depression was present in 21.9 and 7.8% of participants, respectively, DSM-IV/5 minor and major depression in 6.2 and 6.1%, respectively, and GAD in 4.8%. There were 110 deaths, 31 cardiovascular deaths, and 199 participants had incident cardiovascular events. In adjusted models, minor anxious depression (Hazard ratio (95% confidence intervals): 1.70 (1.15-2.50)) and major anxious depression (1.90 (1.11-3.25)) predicted incident cardiovascular events and major anxious depression also predicted cardiovascular mortality (4.32 (1.35-13.86)). By comparison, incident cardiovascular events were predicted by DSM-IV/5 major depression (2.10 (1.22-3.62)) only and cardiovascular mortality was predicted by both DSM-IV/5 major depression (3.56 (1.03-12.35)) and GAD (5.92 (1.84-19.08)). LCA-defined anxious depression is more common than DSM-IV/5 categories and is a strong predictor of cardiovascular outcomes in type 2 diabetes. These data suggest that this diagnostic scheme has predictive validity and clinical relevance. © 2016 Wiley Periodicals, Inc.

Medical Complexity among Children with Special Health Care Needs: A Two-Dimensional View.

PubMed

Coller, Ryan J; Lerner, Carlos F; Eickhoff, Jens C; Klitzner, Thomas S; Sklansky, Daniel J; Ehlenbach, Mary; Chung, Paul J

2016-08-01

To identify subgroups of U.S. children with special health care needs (CSHCN) and characterize key outcomes. Secondary analysis of 2009-2010 National Survey of CSHCN. Latent class analysis grouped individuals into substantively meaningful classes empirically derived from measures of pediatric medical complexity. Outcomes were compared among latent classes with weighted logistic or negative binomial regression. LCA identified four unique CSHCN subgroups: broad functional impairment (physical, cognitive, and mental health) with extensive health care (Class 1), broad functional impairment alone (Class 2), predominant physical impairment requiring family-delivered care (Class 3), and physical impairment alone (Class 4). CSHCN from Class 1 had the highest ED visit rates (IRR 3.3, p < .001) and hospitalization odds (AOR: 12.0, p < .001) and lowest odds of a medical home (AOR: 0.17, p < .001). CSHCN in Class 3, despite experiencing more shared decision making and medical home attributes, had more ED visits and missed school than CSHCN in Class 2 (p < .001); the latter, however, experienced more cost-related difficulties, care delays, and parents having to stop work (p < .001). Recognizing distinct impacts of cognitive and mental health impairments and health care delivery needs on CSHCN outcomes may better direct future intervention efforts. © Health Research and Educational Trust.

Moving into poverty during childhood is associated with later sleep problems.

PubMed

Sivertsen, Børge; Bøe, Tormod; Skogen, Jens Christoffer; Petrie, Keith J; Hysing, Mari

2017-09-01

A social gradient in sleep has been demonstrated across the life span, but previous studies have been cross-sectional and used self-reported socioeconomic status (SES) indicators. Using registry-based data on family income trajectories, the current study examined the association between relative poverty in childhood and subsequent sleep in adolescence. Data on family income during 2004-2010 was obtained from the National Income Registry. Poverty was defined as household income <60% of the mean national income. Information on self-reported sleep was based the youth@hordaland-survey (n = 8873) conducted in 2012 when the adolescents were 16-19 years old. Latent class analysis (LCA) was used to identify trajectories of family household poverty, and analysis of variance and general linear models were used to examine associations between income trajectories and sleep, adjusting for confounders. LCA identified four classes: 'never poor', two classes characterized by moving in or out of poverty, and 'chronically poor'. Compared to the 'never poor' group, adolescents from families in the 'moving into poverty' group displayed worse sleep across most sleep measures, including shorter sleep, lower sleep efficiency, and more nocturnal wake time (but not sleep onset latency). Neither adolescents from families who had moved out of poverty by increasing family income, nor the 'chronically poor' group differed significantly from the reference group. The study found that downward socioeconomic mobility was associated with increased adolescent sleep problems. More studies are required on the mechanisms that may account for the association, to find targeted and effective strategies to prevent short sleep duration in adolescents from families with unstable financial circumstances. Copyright © 2017 Elsevier B.V. All rights reserved.

Application of life cycle assessment for an evaluation of wastewater treatment and reuse project--case study of Xi'an, China.

PubMed

Zhang, Q H; Wang, X C; Xiong, J Q; Chen, R; Cao, B

2010-03-01

In order to illuminate the benefit of a wastewater treatment and reuse project, a life cycle assessment (LCA) model was proposed by combining the process-based LCA and the input-output based LCA in one framework and using energy consumption as the sole parameter for quantitative evaluation of the project. The life cycle consumption was evaluated mainly by life cycle inventory (LCI) analysis taking into account the construction phase, operation phase and demolishment phase of the project. For evaluating the life cycle benefit of treated water reuse, attention was paid to the decrease of secondary effluent discharge and water saving. As a result of comprehensive LCA analysis of a case project in Xi'an, China, it was understood that the life cycle benefit gained from treated wastewater reuse much surpassed the life cycle energy consumption. The advantage of wastewater treatment and reuse was well shown by LCA analysis using the proposed model. 2009 Elsevier Ltd. All rights reserved.

The Structure of Co-Occurring Bullying Experiences and Associations with Suicidal Behaviors in Korean Adolescents

PubMed Central

Roh, Beop-Rae; Yoon, Yoewon; Kwon, Ahye; Oh, Seunga; Lee, Soyoung Irene; Ha, Kyunghee; Shin, Yun Mi; Song, Jungeun; Park, Eun Jin; Yoo, Heejung; Hong, Hyun Ju

2015-01-01

Objective This study had two main goals: to examine the structure of co-occurring peer bullying experiences among adolescents in South Korea from the perspective of victims and to determine the effects of bullying on suicidal behavior, including suicidal ideation and suicide attempts, among adolescents. Method This study used data gathered from 4,410 treatment-seeking adolescents at their initial visits to 31 local mental health centers in Gyeonggi Province, South Korea. The structure of peer bullying was examined using latent class analysis (LCA) to classify participants’ relevant experiences. Then, a binomial logistic regression adjusted by propensity scores was conducted to identify relationships between experiences of being bullied and suicidal behaviors. Results The LCA of experiences with bullying revealed two distinct classes of bullying: physical and non-physical. Adolescents who experienced physical bullying were 3.05 times more likely to attempt suicide than those who were not bullied. Victims of (non-physical) cyber bullying were 2.94 times more likely to attempt suicide than were those who were not bullied. Conclusions Both physical and non-physical bullying were associated with suicide attempts, with similar effect sizes. Schools and mental health professionals should be more attentive than they currently are to non-physical bullying. PMID:26619356

Comprehensive analysis of genetic variations in strictly-defined Leber congenital amaurosis with whole-exome sequencing in Chinese.

PubMed

Wang, Shi-Yuan; Zhang, Qi; Zhang, Xiang; Zhao, Pei-Quan

2016-01-01

To make a comprehensive analysis of the potential pathogenic genes related with Leber congenital amaurosis (LCA) in Chinese. LCA subjects and their families were retrospectively collected from 2013 to 2015. Firstly, whole-exome sequencing was performed in patients who had underwent gene mutation screening with nothing found, and then homozygous sites was selected, candidate sites were annotated, and pathogenic analysis was conducted using softwares including Sorting Tolerant from Intolerant (SIFT), Polyphen-2, Mutation assessor, Condel, and Functional Analysis through Hidden Markov Models (FATHMM). Furthermore, Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of pathogenic genes were performed followed by co-segregation analysis using Fisher exact Test. Sanger sequencing was used to validate single-nucleotide variations (SNVs). Expanded verification was performed in the rest patients. Totally 51 LCA families with 53 patients and 24 family members were recruited. A total of 104 SNVs (66 LCA-related genes and 15 co-segregated genes) were submitted for expand verification. The frequencies of homozygous mutation of KRT12 and CYP1A1 were simultaneously observed in 3 families. Enrichment analysis showed that the potential pathogenic genes were mainly enriched in functions related to cell adhesion, biological adhesion, retinoid metabolic process, and eye development biological adhesion. Additionally, WFS1 and STAU2 had the highest homozygous frequencies. LCA is a highly heterogeneous disease. Mutations in KRT12, CYP1A1, WFS1, and STAU2 may be involved in the development of LCA.

A Latent Class Analysis of Heterosexual Young Men’s Masculinities

PubMed Central

Masters, N. Tatiana; Beadnell, Blair; Wells, Elizabeth A.; Morrison, Diane M.; Hoppe, Marilyn J.

2015-01-01

Parallel bodies of research have described the diverse and complex ways that men understand and construct their masculine identities (often termed“masculinities”) and, separately, how adherence to traditional notions of masculinity places men at risk for negative sexual and health outcomes. The goal of this analysis was to bring together these two streams of inquiry. Using data from a national, online sample of 555 hetero-sexually active young men, we employed latent class analysis (LCA) to detect patterns of masculine identities based on men’s endorsement of behavioral and attitudinal indicators of“dominant” masculinity, including sexual attitudes and behaviors. LCA identified four conceptually distinct masculine identity profiles. Twogroups, termed the Normative and Normative/Male Activities groups, respectively, constituted 88 % of the sample and were characterized by low levels of adherence to attitudes, sexual scripts, and behaviors consistent with“dominant”masculinity, but differed in their levels of engagement in male-oriented activities (e.g., sports teams). Only eight percent of the sample comprised a masculinity profile consistent with “traditional” ideas about masculinity; this group was labeled Misogynistic because of high levels of sexual assault and violence toward female partners. The remaining four percent constituted a Sex-Focused group, characterized by high numbers of sexual partners, but relatively low endorsement of other indicators of traditional masculinity. Follow-up analyses showed a small number of differences across groups on sexual and substance use health indicators. Findings have implications for sexual and behavioral health interventions and suggest that very few young men embody or endorse rigidly traditional forms of masculinity. PMID:26496914

[The accreditation of professional competence: the analysis of nursing
interventions to control anxiety in surgical patients].

PubMed

Brea-Rivero, Pilar; Herrera-Usagre, Manuel; Rojas-de-Mora-Figueroa, Ana; Esposito, Thomas

2016-01-01

. The accreditation of professional competence: the analysis of nursing interventions to control anxiety in surgical patients. The preoperative anxiety is a state of discomfort or unpleasant tension resulting from concerns about illness, hospitalization, anesthesia, surgery or the unknown. Nurses play a vital role reducing preoperative anxiety. An accreditation program was developed in Andalusia (Spain) to measure nurses' competences in this and others fields. To analyze the accredited nurses' interventions spectrum to reduce anxiety in surgical patients and to check if their range of interventions depends upon their professional skills accreditation level. Cross-sectional study. From 20016 to 2014, 1.282 interventions performed by 303 operating room nurses accredited through the Professional Skills Accreditation Program of the Andalusian Agency for Health Care Quality (ACSA) were analyzed with the latent class analysis (LCA) and multinomial logistic regression. Two-thirds of the sample was accredited in Advanced level, about 31% in Expert level and 2.6% in Excellent level. Mean age of patients was 58.5±19.8 years. Three professional profiles were obtained from the LCA. Those nurses classified in Class I (22.4% of the sample) were more likely to be women, to can for younger patients, and to be accredited in Expert or Excellent Level and to perform the larger range of interventions, becoming therefore the most complete professional profile. Those nurses who perform a wider range of interventions and specifically two evidence based interventions such Calming Technique and Coping Enhancement are those who have a higher level of accreditation level.

A Latent Class Analysis of Heterosexual Young Men's Masculinities.

PubMed

Casey, Erin A; Masters, N Tatiana; Beadnell, Blair; Wells, Elizabeth A; Morrison, Diane M; Hoppe, Marilyn J

2016-07-01

Parallel bodies of research have described the diverse and complex ways that men understand and construct their masculine identities (often termed "masculinities") and, separately, how adherence to traditional notions of masculinity places men at risk for negative sexual and health outcomes. The goal of this analysis was to bring together these two streams of inquiry. Using data from a national, online sample of 555 heterosexually active young men, we employed latent class analysis (LCA) to detect patterns of masculine identities based on men's endorsement of behavioral and attitudinal indicators of "dominant" masculinity, including sexual attitudes and behaviors. LCA identified four conceptually distinct masculine identity profiles. Two groups, termed the Normative and Normative/Male Activities groups, respectively, constituted 88 % of the sample and were characterized by low levels of adherence to attitudes, sexual scripts, and behaviors consistent with "dominant" masculinity, but differed in their levels of engagement in male-oriented activities (e.g., sports teams). Only eight percent of the sample comprised a masculinity profile consistent with "traditional" ideas about masculinity; this group was labeled Misogynistic because of high levels of sexual assault and violence toward female partners. The remaining four percent constituted a Sex-Focused group, characterized by high numbers of sexual partners, but relatively low endorsement of other indicators of traditional masculinity. Follow-up analyses showed a small number of differences across groups on sexual and substance use health indicators. Findings have implications for sexual and behavioral health interventions and suggest that very few young men embody or endorse rigidly traditional forms of masculinity.

Smoking patterns, quit behaviors, and smoking environment of workers in small manufacturing companies

PubMed Central

Pinsker, Erika A.; Hennrikus, Deborah J.; Hannan, Peter J.; Lando, Harry A; Brosseau, Lisa M.

2016-01-01

Background This study describes smokers employed at 47 small manufacturing companies in Minnesota, USA. Methods Smokers (n=713) participating in a group-randomized trial completed a baseline survey on their smoking patterns, quit behaviors, smoking environment, workplace attitudes about smoking, and correlates of smoking. These characteristics were examined by job type and a latent class analysis (LCA) was performed to group workers with similar characteristics. Results Production workers had the highest prevalence of daily smoking (88% vs. 68% among managers), and addiction (61% vs. 26% among managers), and the highest mean level of perceived stress (6.4 vs. 4.9 among managers). The LCA identified 3 subgroups of smokers that differed in levels of barriers to cessation. Production workers were most likely to be in the group with greater barriers (p=.01). Conclusions These results underscore the importance of targeting interventions to production workers and those who exhibit the greatest barriers to cessation. PMID:26179203

Polydrug use typologies and childhood maltreatment in a nationally representative survey of Danish young adults.

PubMed

Armour, Cherie; Shorter, Gillian W; Elhai, Jon D; Elklit, Ask; Christoffersen, Mogens N

2014-01-01

Substance use and childhood maltreatment experience are linked, but little is known about the association with polydrug use patterns. Latent class analyses (LCA) were performed on eight illicit drugs in a random population sample of young Danes separated by sex (males: n = 1,555; females: n = 1,425). Logistic regressions explored associations of polydrug use patterns and childhood maltreatment. A three-class solution best described patterns of polydrug use in both the male and female samples. Across all LCA models, Class 1 was characterized by individuals who represented wide-range polydrug users, endorsing many of the drug types (males = 8%; females = 2%). Class 2 was characterized by amphetamine, cannabis, cocaine, and amyl nitrate users (males = 18%; females = 7%). Class 3 was characterized by individuals who endorsed either low-level use of cannabis only or no drug use (males = 74%; females = 91 %). For males, having been a child-protection case was associated with Classes 1 and 2 and for females with Class 2, compared with Class 3. Alcohol problems were associated with Classes 1 and 2 for both sexes. Sexual abuse was associated with Classes 1 and 2 for females but not males, whereas physical abuse was associated with Classes 1 and 2 for males but not females, as compared with Class 3. Separate sex analyses are important; although patterns of polydrug use are broadly similar, females are less frequently polydrug users. In addition, different relationships exist for the sexes, such that polydrug use patterns are associated with sexual abuse in females, whereas such patterns are associated with physical abuse in young males.

ADHD latent class clusters: DSM-IV subtypes and comorbidity

PubMed Central

Elia, Josephine; Arcos-Burgos, Mauricio; Bolton, Kelly L.; Ambrosini, Paul J.; Berrettini, Wade; Muenke, Maximilian

2014-01-01

ADHD (Attention Deficit Hyperactivity Disorder) has a complex, heterogeneous phenotype only partially captured by Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. In this report, latent class analyses (LCA) are used to identify ADHD phenotypes using K-SADS-IVR (Schedule for Affective Disorders & Schizophrenia for School Age Children-IV-Revised) symptoms and symptom severity data from a clinical sample of 500 ADHD subjects, ages 6–18, participating in an ADHD genetic study. Results show that LCA identified six separate ADHD clusters, some corresponding to specific DSM-IV subtypes while others included several subtypes. DSM-IV comorbid anxiety and mood disorders were generally similar across all clusters, and subjects without comorbidity did not aggregate within any one cluster. Age and gender composition also varied. These results support findings from population-based LCA studies. The six clusters provide additional homogenous groups that can be used to define ADHD phenotypes in genetic association studies. The limited age ranges aggregating in the different clusters may prove to be a particular advantage in genetic studies where candidate gene expression may vary during developmental phases. DSM-IV comorbid mood and anxiety disorders also do not appear to increase cluster heterogeneity; however, longitudinal studies that cover period of risk are needed to support this finding. PMID:19900717

Spirituality and positive psychology go hand in hand: an investigation of multiple empirically derived profiles and related protective benefits.

PubMed

Barton, Yakov A; Miller, Lisa

2015-06-01

We investigate the relationship between personal spirituality and positive psychology traits as potentially presented in multiple profiles, rather than monolithically across a full sample. A sample of 3966 adolescents and emerging adults (aged 18-25, mean = 20.19, SD = 2.08) and 2014 older adults (aged 26-82, mean = 38.41, SD = 11.26) completed a survey assessing daily spiritual experiences (relationship with a Higher Power and sense of a sacred world), forgiveness, gratitude, optimism, grit, and meaning. To assess the relative protective benefits of potential profiles, we also assessed the level of depressive symptoms and frequency of substance use (tobacco, marijuana, alcohol, and heavy alcohol use). Latent class analysis (LCA) was used to examine common subgroupings of study participants across report on personal spirituality and positive psychology scales in each age cohort, with potential difference between latent classes then tested in level of depressive symptoms and degree of substance use. LCA determined a four-class and a three-class best-fitting models for the younger and older cohorts, respectively. Level of personal spirituality and level of positive psychology traits were found to coincide in 83 % of adolescents and emerging adults and in 71 % of older adults, suggesting personal spirituality and positive psychology traits go hand in hand. A minority subgroup of "virtuous humanists" showed high levels of positive psychology traits but low levels of personal spirituality, across both age cohorts. Whereas level of depression was found to be inversely associated with positive psychology traits and personal spirituality, uniquely personal spirituality was protective against degree of substance use across both age cohorts. Overall interpretation of the study findings suggests that personal spirituality may be foundational to positive psychology traits in the majority of people.

Parent, Sibling and Peer Associations with Subtypes of Psychiatric and Substance Use Disorder Comorbidity in Offspring

PubMed Central

McCutcheon, Vivia V.; Scherrer, Jeffrey F.; Grant, Julia D.; Xian, Hong; Haber, Jon Randolph; Jacob, Theodore; Bucholz, Kathleen K

2012-01-01

BACKGROUND Parental substance use disorder (SUD) is associated with a range of negative offspring outcomes and psychopathology, but the clustering of these outcomes into subtypes has seldom been examined, nor have the familial and environmental contexts of these subtypes been reported. The present study examines the clustering of offspring lifetime substance use and psychiatric disorders into subtypes and characterizes them in terms of familial and non-familial influences using an offspring-of-twins design. METHOD Telephone-administered diagnostic interviews were used to collect data on psychiatric disorders and SUD from 488 twin fathers, 420 biological mothers and 831 offspring. Latent class analysis (LCA) was used to derive subtypes of lifetime comorbidity in offspring. Familial risk and environmental variables associated with each subtype (i.e. parenting, childhood physical or sexual abuse, perceived sibling and peer substance use) were identified using multinomial logistic regression. RESULTS Four classes identified by LCA were characterized as 1) unaffected, 2) alcohol abuse/dependence, 3) alcohol abuse/dependence comorbid with anxiety and depression, and 4) alcohol, cannabis abuse/dependence and nicotine dependence comorbid with conduct disorder. Inconsistent parenting, childhood physical/sexual abuse, and perceived sibling and peer substance use were significantly associated with profiles of offspring comorbidity after adjusting for familial vulnerability. Some associations were specific (i.e. perceived peer alcohol use to the AUD class), while others were general (peer smoking to all 3 comorbidity classes). CONCLUSIONS We observed distinct subtypes of psychiatric and SUD comorbidity in adolescents and young adults. Subtypes of offspring psychopathology have varied associations with parental psychopathology, family environment, and sibling and peer behaviors. PMID:22921146

Comprehensive analysis of genetic variations in strictly-defined Leber congenital amaurosis with whole-exome sequencing in Chinese

PubMed Central

Wang, Shi-Yuan; Zhang, Qi; Zhang, Xiang; Zhao, Pei-Quan

2016-01-01

AIM To make a comprehensive analysis of the potential pathogenic genes related with Leber congenital amaurosis (LCA) in Chinese. METHODS LCA subjects and their families were retrospectively collected from 2013 to 2015. Firstly, whole-exome sequencing was performed in patients who had underwent gene mutation screening with nothing found, and then homozygous sites was selected, candidate sites were annotated, and pathogenic analysis was conducted using softwares including Sorting Tolerant from Intolerant (SIFT), Polyphen-2, Mutation assessor, Condel, and Functional Analysis through Hidden Markov Models (FATHMM). Furthermore, Gene Ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of pathogenic genes were performed followed by co-segregation analysis using Fisher exact Test. Sanger sequencing was used to validate single-nucleotide variations (SNVs). Expanded verification was performed in the rest patients. RESULTS Totally 51 LCA families with 53 patients and 24 family members were recruited. A total of 104 SNVs (66 LCA-related genes and 15 co-segregated genes) were submitted for expand verification. The frequencies of homozygous mutation of KRT12 and CYP1A1 were simultaneously observed in 3 families. Enrichment analysis showed that the potential pathogenic genes were mainly enriched in functions related to cell adhesion, biological adhesion, retinoid metabolic process, and eye development biological adhesion. Additionally, WFS1 and STAU2 had the highest homozygous frequencies. CONCLUSION LCA is a highly heterogeneous disease. Mutations in KRT12, CYP1A1, WFS1, and STAU2 may be involved in the development of LCA. PMID:27672588

An Assessment of Character and Leadership Development Latent Factor Structures through Confirmatory Factor, Item Response Theory, and Latent Class Analyses

ERIC Educational Resources Information Center

Higginbotham, David L.

2013-01-01

This study leveraged the complementary nature of confirmatory factor (CFA), item response theory (IRT), and latent class (LCA) analyses to strengthen the rigor and sophistication of evaluation of two new measures of the Air Force Academy's "leader of character" definition--the Character Mosaic Virtues (CMV) and the Leadership Mosaic…

Using latent class analysis to identify academic and behavioral risk status in elementary students.

PubMed

King, Kathleen R; Lembke, Erica S; Reinke, Wendy M

2016-03-01

Identifying classes of children on the basis of academic and behavior risk may have important implications for the allocation of intervention resources within Response to Intervention (RTI) and Multi-Tiered System of Support (MTSS) models. Latent class analysis (LCA) was conducted with a sample of 517 third grade students. Fall screening scores in the areas of reading, mathematics, and behavior were used as indicators of success on an end of year statewide achievement test. Results identified 3 subclasses of children, including a class with minimal academic and behavioral concerns (Tier 1; 32% of the sample), a class at-risk for academic problems and somewhat at-risk for behavior problems (Tier 2; 37% of the sample), and a class with significant academic and behavior problems (Tier 3; 31%). Each class was predictive of end of year performance on the statewide achievement test, with the Tier 1 class performing significantly higher on the test than the Tier 2 class, which in turn scored significantly higher than the Tier 3 class. The results of this study indicated that distinct classes of children can be determined through brief screening measures and are predictive of later academic success. Further implications are discussed for prevention and intervention for students at risk for academic failure and behavior problems. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Noise characteristics in DORIS station positions time series derived from IGN-JPL, INASAN and CNES-CLS analysis centres

NASA Astrophysics Data System (ADS)

Khelifa, S.

2014-12-01

Using wavelet transform and Allan variance, we have analysed the solutions of weekly position residuals of 09 high latitude DORIS stations in STCD (STation Coordinate Difference) format provided from the three Analysis Centres : IGN-JPL (solution ign11wd01), INASAN (solution ina10wd01) and CNES-CLS (solution lca11wd02), in order to compare the spectral characteristics of their residual noise. The temporal correlations between the three solutions, two by two and station by station, for each component (North, East and Vertical) reveal a high correlation in the horizontal components (North and East). For the North component, the correlation average is about 0.88, 0.81 and 0.79 between, respectively, IGN-INA, IGN-LCA and INA-LCA solutions, then for the East component it is about 0.84, 0.82 and 0.76, respectively. However, the correlations for the Vertical component are moderate with an average of 0.64, 0.57 and 0.58 in, respectively, IGN-INA, IGN-LCA and INA-LCA solutions. After removing the trends and seasonal components from the analysed time series, the Allan variance analysis shows that the three solutions are dominated by a white noise in the all three components (North, East and Vertical). The wavelet transform analysis, using the VisuShrink method with soft thresholding, reveals that the noise level in the LCA solution is less important compared to IGN and INA solutions. Indeed, the standard deviation of the noise for the three components is in the range of 5-11, 5-12 and 4-9mm in the IGN, INA, and LCA solutions, respectively.

Further potentials in the joint implementation of life cycle assessment and data envelopment analysis.

PubMed

Iribarren, Diego; Vázquez-Rowe, Ian; Moreira, María Teresa; Feijoo, Gumersindo

2010-10-15

The combined application of Life Cycle Assessment and Data Envelopment Analysis has been recently proposed to provide a tool for the comprehensive assessment of the environmental and operational performance of multiple similar entities. Among the acknowledged advantages of LCA+DEA methodology, eco-efficiency verification and avoidance of average inventories are usually highlighted. However, given the novelty of LCA+DEA methods, a high number of additional potentials remain unexplored. In this sense, there are some features that are worth detailing given their wide interest to enhance LCA performance. Emphasis is laid on the improved interpretation of LCA results through the complementary use of DEA with respect to: (i) super-efficiency analysis to facilitate the selection of reference performers, (ii) inter- and intra-assessments of multiple data sets within any specific sector with benchmarking and trend analysis purposes, (iii) integration of an economic dimension in order to enrich sustainability assessments, and (iv) window analysis to evaluate environmental impact efficiency over a certain period of time. Furthermore, the capability of LCA+DEA methodology to be generally implemented in a wide range of scenarios is discussed. These further potentials are explained and demonstrated via the presentation of brief case studies based on real data sets. Copyright © 2010 Elsevier B.V. All rights reserved.

Life cycle assessment and residue leaching: The importance of parameter, scenario and leaching data selection

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

Allegrini, E., E-mail: elia@env.dtu.dk; Butera, S.; Kosson, D.S.

Highlights: • Relevance of metal leaching in waste management system LCAs was assessed. • Toxic impacts from leaching could not be disregarded. • Uncertainty of toxicity, due to background activities, determines LCA outcomes. • Parameters such as pH and L/S affect LCA results. • Data modelling consistency and coverage within an LCA are crucial. - Abstract: Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products andmore » can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies.« less

Considering time in LCA: dynamic LCA and its application to global warming impact assessments.

PubMed

Levasseur, Annie; Lesage, Pascal; Margni, Manuele; Deschênes, Louise; Samson, Réjean

2010-04-15

The lack of temporal information is an important limitation of life cycle assessment (LCA). A dynamic LCA approach is proposed to improve the accuracy of LCA by addressing the inconsistency of temporal assessment. This approach consists of first computing a dynamic life cycle inventory (LCI), considering the temporal profile of emissions. Then, time-dependent characterization factors are calculated to assess the dynamic LCI in real-time impact scores for any given time horizon. Although generally applicable to any impact category, this approach is developed here for global warming, based on the radiative forcing concept. This case study demonstrates that the use of global warming potentials for a given time horizon to characterize greenhouse gas emissions leads to an inconsistency between the time frame chosen for the analysis and the time period covered by the LCA results. Dynamic LCA is applied to the US EPA LCA on renewable fuels, which compares the life cycle greenhouse gas emissions of different biofuels with fossil fuels including land-use change emissions. The comparison of the results obtained with both traditional and dynamic LCA approaches shows that the difference can be important enough to change the conclusions on whether or not a biofuel meets some given global warming reduction targets.

An Integrated Approach to Life Cycle Analysis

NASA Technical Reports Server (NTRS)

Chytka, T. M.; Brown, R. W.; Shih, A. T.; Reeves, J. D.; Dempsey, J. A.

2006-01-01

Life Cycle Analysis (LCA) is the evaluation of the impacts that design decisions have on a system and provides a framework for identifying and evaluating design benefits and burdens associated with the life cycles of space transportation systems from a "cradle-to-grave" approach. Sometimes called life cycle assessment, life cycle approach, or "cradle to grave analysis", it represents a rapidly emerging family of tools and techniques designed to be a decision support methodology and aid in the development of sustainable systems. The implementation of a Life Cycle Analysis can vary and may take many forms; from global system-level uncertainty-centered analysis to the assessment of individualized discriminatory metrics. This paper will focus on a proven LCA methodology developed by the Systems Analysis and Concepts Directorate (SACD) at NASA Langley Research Center to quantify and assess key LCA discriminatory metrics, in particular affordability, reliability, maintainability, and operability. This paper will address issues inherent in Life Cycle Analysis including direct impacts, such as system development cost and crew safety, as well as indirect impacts, which often take the form of coupled metrics (i.e., the cost of system unreliability). Since LCA deals with the analysis of space vehicle system conceptual designs, it is imperative to stress that the goal of LCA is not to arrive at the answer but, rather, to provide important inputs to a broader strategic planning process, allowing the managers to make risk-informed decisions, and increase the likelihood of meeting mission success criteria.

The Committed Intimate Partnerships of Incarcerated African-American Men: Implications for Sexual HIV Transmission Risk and Prevention Opportunities.

PubMed

Khan, Maria R; El-Bassel, Nabila; Golin, Carol E; Scheidell, Joy D; Adimora, Adaora A; Coatsworth, Ashley M; Hu, Hui; Judon-Monk, Selena; Medina, Katie P; Wohl, David A

2017-10-01

Incarceration is thought to influence HIV transmission by disrupting partnerships that provide support and protect against sex risk-taking. Current correctional facility-based family-strengthening programs focus on marital partnerships, a minority of inmates' partnerships. Research on the sex partnerships of incarcerated African-American men and the types of partnerships most likely to protect against HIV-related sex risk is limited. Improved understanding can inform expansion of correctional facility-based family-strengthening programs to a greater proportion of protective partnerships and HIV risk reduction programs to partnerships vulnerable to sex risk. Project DISRUPT is a cohort study of African-American men being released from prison in North Carolina who were in committed heterosexual partnerships at prison entry. Using baseline survey data (N = 189), we conducted latent class analysis (LCA) to identify subgroups of participants with distinct relationship profiles and measured associations between relationship characteristics and multiple partnerships of inmates and their partners in the six months before incarceration. LCA indicated a two-class solution, with relationships distinguished by satisfaction/stability (satisfied/stable class: 58.0%; dissatisfied/unstable class: 42.0%); each class had comparable relationship length and levels of marriage and cohabitation. Dissatisfied/unstable relationships were associated with multiple partnerships among participants (AOR 2.93, 95% CI 1.50, 5.72) and partners (AOR 4.95, 95% CI 1.68, 14.58). Satisfaction indicators-versus length, marriage, or cohabitation-were the strongest independent correlates of inmates' and partners' multiple partnerships. Pre-incarceration economic deprivation, mental disorder symptoms, substance use, and violence in relationships were associated with dissatisfaction/instability. Prison-based programs designed to maintain healthy partnerships, strengthen relationship skills, and reduce HIV risk-taking and violence in relationships are warranted and should be targeted to both marital and nonmarital partnerships. Programming also should address the poverty, mental illness, and substance use factors that threaten relationship satisfaction/stability and increase HIV risk.

Evidence of the dissociative PTSD subtype: A systematic literature review of latent class and profile analytic studies of PTSD.

PubMed

Hansen, Maj; Ross, Jana; Armour, Cherie

2017-04-15

The dissociative PTSD (D-PTSD) subtype was first introduced into the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. Prior to this, studies using latent profile analysis (LPA) or latent class analysis (LCA), began to provide support for the D-PTSD construct and associated risk factors. This research is important, because dissociative symptoms in the context of PTSD may potentially interfere with treatment course or outcome. The aims of the present study were twofold: to systematically review the LCA and LPA studies investigating support for the D-PTSD construct; and to review the associated research on the risk factors or covariates of D-PTSD in the identified studies. Six databases (PubMed, Web of Science, Scopus, PILOTS, PsychInfo, and Embase) were systematically searched for relevant papers. Eleven studies were included in the present review. The majority of the studies were supportive of the D-PTSD subtype; primarily characterized by depersonalization and derealization. Several covariates of the D-PTSD subtype have been investigated with mixed results. Many limitations relate to the state of the current literature, including a small number of studies, the use of self-report measurements of PTSD, and heterogeneity across the samples in investigated covariates. The results were overall supportive of the D-PTSD construct. Future research on D-PTSD and associated risk factors is needed to shed light on the possibilities of facilitating preventive actions, screening, and implications on treatment effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Latent Class Analysis of Gambling Activities in a Sample of Young Swiss Men: Association with Gambling Problems, Substance Use Outcomes, Personality Traits and Coping Strategies.

PubMed

Studer, Joseph; Baggio, Stéphanie; Mohler-Kuo, Meichun; Simon, Olivier; Daeppen, Jean-Bernard; Gmel, Gerhard

2016-06-01

The study aimed to identify different patterns of gambling activities (PGAs) and to investigate how PGAs differed in gambling problems, substance use outcomes, personality traits and coping strategies. A representative sample of 4989 young Swiss males completed a questionnaire assessing seven distinct gambling activities, gambling problems, substance use outcomes, personality traits and coping strategies. PGAs were identified using latent class analysis (LCA). Differences between PGAs in gambling and substance use outcomes, personality traits and coping strategies were tested. LCA identified six different PGAs. With regard to gambling and substance use outcomes, the three most problematic PGAs were extensive gamblers, followed by private gamblers, and electronic lottery and casino gamblers, respectively. By contrast, the three least detrimental PGAs were rare or non-gamblers, lottery only gamblers and casino gamblers. With regard to personality traits, compared with rare or non-gamblers, private and casino gamblers reported higher levels of sensation seeking. Electronic lottery and casino gamblers, private gamblers and extensive gamblers had higher levels of aggression-hostility. Extensive and casino gamblers reported higher levels of sociability, whereas casino gamblers reported lower levels of anxiety-neuroticism. Extensive gamblers used more maladaptive and less adaptive coping strategies than other groups. Results suggest that gambling is not a homogeneous activity since different types of gamblers exist according to the PGA they are engaged in. Extensive gamblers, electronic and casino gamblers and private gamblers may have the most problematic PGAs. Personality traits and coping skills may predispose individuals to PGAs associated with more or less negative outcomes.

Race Differences in Patterns of Risky Behavior and Associated Risk Factors in Adolescence.

PubMed

Childs, Kristina K; Ray, James V

2017-05-01

Using data from the National Longitudinal Study of Adolescent Health (Add Health), this study expands on previous research by (a) examining differences across race in patterns or "subgroups" of adolescents based on nine self-reported behaviors (e.g., delinquency, substance use, risky sexual practices) and (b) comparing the risk factors (e.g., peer association, parenting, neighborhood cohesion), both within and across the race-specific subgroups, related to membership into the identified latent classes. The data used in this study include respondents aged 13 to 17 who participated in Waves 1 and 2 of the Add Health in-home interview. Latent class analysis (LCA) identified key differences in the number and characteristics of the latent classes across the racial subgroups. In addition, both similarities and differences in the risk factors for membership into the latent classes were identified across and within the race-specific subgroups. Implications for understanding risky behavior in adolescence, as well as directions for future research, are discussed.

Risk-taking behaviors and subgrouping of suicide in Iran: A latent class analysis of national registries data.

PubMed

Hajebi, Ahmad; Abbasi-Ghahramanloo, Abbas; Hashemian, Seyed Sepehr; Khatibi, Seyed Reza; Ghasemzade, Masomeh; Khodadost, Mahmoud

2017-09-01

Suicide is one the most important public health problem which is rapidly growing concerns. The aim of this study was to subgroup suicide using LCA method. This cross-sectional study was conducted in Iran based on 66990 records registered in Ministry of Health in 2014. A case report questionnaire in the form of software was used for case registries. Latent class analysis was used to achieve the research objectives. Four latent classes were identified; (a) Non-lethal attempters without a history of psychiatric disorders, (b) Non-lethal attempters with a history of psychiatric disorders, (c) Lethal attempters without a history of psychiatric disorders, (d) Lethal attempters with a history of psychiatric disorders. The probability of completed/an achieved suicide is high in lethal attempter classes. Being male increases the risk of inclusion in lethal attempters' classes (OR = 4.93). Also, being single (OR = 1.16), having an age lower than 25 years (OR = 1.14) and being a rural citizen (OR = 2.36) associate with lethal attempters classes. The males tend to use more violent methods and have more completed suicide. Majority of the individuals are non-lethal attempters who need to be addressed by implementing preventive interventions and mental support provision. Copyright © 2017. Published by Elsevier B.V.

Using a hybrid subtyping model to capture patterns and dimensionality of depressive and anxiety symptomatology in the general population.

PubMed

Wardenaar, Klaas J; Wanders, Rob B K; Ten Have, Margreet; de Graaf, Ron; de Jonge, Peter

2017-06-01

Researchers have tried to identify more homogeneous subtypes of major depressive disorder (MDD) with latent class analyses (LCA). However, this approach does no justice to the dimensional nature of psychopathology. In addition, anxiety and functioning-levels have seldom been integrated in subtyping efforts. Therefore, this study used a hybrid discrete-dimensional approach to identify subgroups with shared patterns of depressive and anxiety symptomatology, while accounting for functioning-levels. The Comprehensive International Diagnostic Interview (CIDI) 1.1 was used to assess previous-year depressive and anxiety symptoms in the Netherlands Mental Health Survey and Incidence Study-1 (NEMESIS-1; n=5583). The data were analyzed with factor analyses, LCA and hybrid mixed-measurement item response theory (MM-IRT) with and without functioning covariates. Finally, the classes' predictors (measured one year earlier) and outcomes (measured two years later) were investigated. A 3-class MM-IRT model with functioning covariates best described the data and consisted of a 'healthy class' (74.2%) and two symptomatic classes ('sleep/energy' [13.4%]; 'mood/anhedonia' [12.4%]). Factors including older age, urbanicity, higher severity and presence of 1-year MDD predicted membership of either symptomatic class vs. the healthy class. Both symptomatic classes showed poorer 2-year outcomes (i.e. disorders, poor functioning) than the healthy class. The odds of MDD after two years were especially increased in the mood/anhedonia class. Symptoms were assessed for the past year whereas current functioning was assessed. Heterogeneity of depression and anxiety symptomatology are optimally captured by a hybrid discrete-dimensional subtyping model. Importantly, accounting for functioning-levels helps to capture clinically relevant interpersonal differences. Copyright © 2017 Elsevier B.V. All rights reserved.

Perceived risk associated with ecstasy use: a latent class analysis approach

PubMed Central

Martins, SS; Carlson, RG; Alexandre, PK; Falck, RS

2011-01-01

This study aims to define categories of perceived health problems among ecstasy users based on observed clustering of their perceptions of ecstasy-related health problems. Data from a community sample of ecstasy users (n=402) aged 18 to 30, in Ohio, was used in this study. Data was analyzed via Latent Class Analysis (LCA) and Regression. This study identified five different subgroups of ecstasy users based on their perceptions of health problems they associated with their ecstasy use. Almost one third of the sample (28.9%) belonged to a class with “low level of perceived problems” (Class 4). About one fourth (25.6%) of the sample (Class 2), had high probabilities of “perceiving problems on sexual-related items”, but generally low or moderate probabilities of perceiving problems in other areas. Roughly one-fifth of the sample (21.1%, Class 1) had moderate probabilities of perceiving ecstasy health-related problems in all areas. A small proportion of respondents (11.9%, Class 5) had high probabilities of reporting “perceived memory and cognitive problems, and of perceiving “ecstasy related-problems in all areas” (12.4%, Class 3). A large proportion of ecstasy users perceive either low or moderate risk associated with their ecstasy use. It is important to further investigate whether lower levels of risk perception are associated with persistence of ecstasy use. PMID:21296504

Patterns of HIV Risks and Related Factors among People Who Inject Drugs in Kermanshah, Iran: A Latent Class Analysis.

PubMed

Sharifi, Hamid; Mirzazadeh, Ali; Noroozi, Alireza; Marshall, Brandon D L; Farhoudian, Ali; Higgs, Peter; Vameghi, Meroe; Mohhamadi Shahboulaghi, Farahnaz; Qorbani, Mostafa; Massah, Omid; Armoon, Bahram; Noroozi, Mehdi

2017-01-01

The objective of this study was to explore patterns of drug use and sexual risk behaviors among people who inject drugs (PWID) in Iran. We surveyed 500 PWID in Kermanshah concerning demographic characteristics, sexual risk behaviors, and drug-related risk behaviors in the month prior to study. We used latent class analysis (LCA) to establish a baseline model of risk profiles and to identify the optimal number of latent classes, and we used ordinal regression to identify factors associated with class membership. Three classes of multiple HIV risk were identified. The probability of membership in the high-risk class was 0.33, compared to 0.26 and 0.40 for the low- and moderate-risk classes, respectively. Compared to members in the lowest-risk class (reference group), the highest-risk class members had higher odds of being homeless (OR = 4.5, CI: 1.44-8.22; p = 0.001) in the past 12 months. Members of the high-risk class had lower odds of regularly visiting a needle and syringe exchange program as compared to the lowest-risk class members (AOR = 0.42, CI: 0.2-0.81; p = 0.01). Findings show the sexual and drug-related HIV risk clusters among PWID in Iran, and emphasize the importance of developing targeted prevention and harm reduction programs for all domains of risk behaviors, both sexual and drug use related.

Can Carbon Nanomaterials Improve CZTS Photovoltaic Devices? Evaluation of Performance and Impacts Using Integrated Life-Cycle Assessment and Decision Analysis.

PubMed

Scott, Ryan P; Cullen, Alison C; Fox-Lent, Cate; Linkov, Igor

2016-10-01

In emergent photovoltaics, nanoscale materials hold promise for optimizing device characteristics; however, the related impacts remain uncertain, resulting in challenges to decisions on strategic investment in technology innovation. We integrate multi-criteria decision analysis (MCDA) and life-cycle assessment (LCA) results (LCA-MCDA) as a method of incorporating values of a hypothetical federal acquisition manager into the assessment of risks and benefits of emerging photovoltaic materials. Specifically, we compare adoption of copper zinc tin sulfide (CZTS) devices with molybdenum back contacts to alternative devices employing graphite or graphene instead of molybdenum. LCA impact results are interpreted alongside benefits of substitution including cost reductions and performance improvements through application of multi-attribute utility theory. To assess the role of uncertainty we apply Monte Carlo simulation and sensitivity analysis. We find that graphene or graphite back contacts outperform molybdenum under most scenarios and assumptions. The use of decision analysis clarifies potential advantages of adopting graphite as a back contact while emphasizing the importance of mitigating conventional impacts of graphene production processes if graphene is used in emerging CZTS devices. Our research further demonstrates that a combination of LCA and MCDA increases the usability of LCA in assessing product sustainability. In particular, this approach identifies the most influential assumptions and data gaps in the analysis and the areas in which either engineering controls or further data collection may be necessary. © 2016 Society for Risk Analysis.

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

Yuan, Chris, E-mail: cyuan@uwm.edu; Wang, Endong; Zhai, Qiang

Temporal homogeneity of inventory data is one of the major problems in life cycle assessment (LCA). Addressing temporal homogeneity of life cycle inventory data is important in reducing the uncertainties and improving the reliability of LCA results. This paper attempts to present a critical review and discussion on the fundamental issues of temporal homogeneity in conventional LCA and propose a theoretical framework for temporal discounting in LCA. Theoretical perspectives for temporal discounting in life cycle inventory analysis are discussed first based on the key elements of a scientific mechanism for temporal discounting. Then generic procedures for performing temporal discounting inmore » LCA is derived and proposed based on the nature of the LCA method and the identified key elements of a scientific temporal discounting method. A five-step framework is proposed and reported in details based on the technical methods and procedures needed to perform a temporal discounting in life cycle inventory analysis. Challenges and possible solutions are also identified and discussed for the technical procedure and scientific accomplishment of each step within the framework. - Highlights: • A critical review for temporal homogeneity problem of life cycle inventory data • A theoretical framework for performing temporal discounting on inventory data • Methods provided to accomplish each step of the temporal discounting framework.« less

Clinical and genetic findings in a family with NMNAT1-associated Leber congenital amaurosis: case report and review of the literature.

PubMed

Hedergott, A; Volk, A E; Herkenrath, P; Thiele, H; Fricke, J; Altmüller, J; Nürnberg, P; Kubisch, C; Neugebauer, A

2015-12-01

Leber congenital amaurosis (LCA) is a severe retinal dystrophy, typically manifesting in the first year of life. Mutations in more than 18 genes have been reported to date. In recent studies, biallelic mutations in NMNAT1 encoding nicotinamide mononucleotide adenylyltransferase 1 have been found to cause LCA. To broaden the knowledge regarding the phenotype of NMNAT1-associated LCA. Clinical ophthalmologic examinations were performed in two sisters with LCA. Whole exome sequencing was performed in one of the affected girls, with subsequent segregation analysis in the affected sister and unaffected parents. The literature was reviewed for reports of NMNAT1-associated LCA. Exome sequencing revealed the known NMNAT1 mutation c.25G>A (p.Val9Met) in a homozygous state. Segregation analysis showed the same homozygous mutation in the affected younger sister. Both parents were found to be heterozygous carriers of the mutation. The two girls both presented with severe visual impairment, nystagmus, central atrophy of the pigment epithelium, and pigment clumping in the periphery before the age of 6 months. Retinal vessels were attenuated. Both children were hyperopic. In the older sister, differential diagnosis included an inflammatory origin, but electrophysiology in her as well as her sister confirmed a diagnosis of LCA. Pallor of the optic nerve head was not present at birth but developed progressively. We confirmed a diagnosis of NMNAT1-associated LCA in two siblings through identification of the mutation (c.25G>A [p. Val9Met]) in a homozygous state. In infants with non-detectable electroretinogram (ERG), along with severe congenital visual dysfunction or blindness and central pigment epithelium atrophy with pigment clumping resembling scarring due to chorioretinitis, LCA due to NMNAT1 mutations should be considered.

Maternal Prenatal Stress and Other Developmental Risk Factors for Adolescent Depression: Spotlight on Sex Differences.

PubMed

Maxwell, Seth D; Fineberg, Anna M; Drabick, Deborah A; Murphy, Shannon K; Ellman, Lauren M

2018-02-01

Maternal stress during pregnancy has been linked to premorbid abnormalities associated with depression (e.g., difficult temperament, cognitive deficits) in offspring. However, few studies have looked across developmental periods to examine maternal stress during pregnancy and offspring depression during adolescence and whether these associations differ by sex. The current study used data from 1711 mother-offspring dyads (offspring sex: 49.8% male) in a longitudinal birth cohort study. Maternal narratives collected during pregnancy were qualitatively coded for stress-related themes by independent raters. Latent class analysis (LCA) identified distinct subgroups of offspring based on exposure to maternal prenatal stress and other developmental factors from the prenatal, childhood, and adolescent periods that have been associated with depression and/or maternal prenatal stress. LCA identified subgroups that were compared to determine whether and to what extent they differed on adolescent depressive symptoms. LCA revealed a subgroup of "high-risk" individuals, characterized by maternal factors during pregnancy (higher ambivalence/negativity and lower positivity towards the pregnancy, higher levels of hassles, lower maternal education and higher maternal age at birth, higher pre-pregnancy BMI) and offspring developmental factors (decreased cognitive functioning during childhood and adolescence, lower perceived parental support during adolescence, and higher levels of maternal depression during adolescence). High-risk females exhibited elevated conduct symptoms and higher birth order, while high-risk males exhibited decreased internalizing symptoms and lower birth order. Both high-risk males and females reported elevated depressive symptoms during adolescence relative to their "low-risk" counterparts.

Towards a general framework for including noise impacts in LCA.

PubMed

Cucurachi, Stefano; Heijungs, Reinout; Ohlau, Katrin

Several damages have been associated with the exposure of human beings to noise. These include auditory effects, i.e., hearing impairment, but also non-auditory physiological ones such as hypertension and ischemic heart disease, or psychological ones such as annoyance, depression, sleep disturbance, limited performance of cognitive tasks or inadequate cognitive development. Noise can also interfere with intended activities, both in daytime and nighttime. ISO 14'040 also indicated the necessity of introducing noise, together with other less developed impact categories, in a complete LCA study, possibly changing the results of many LCA studies already available. The attempts available in the literature focused on the integration of transportation noise in LCA. Although being considered the most frequent source of intrusive impact, transportation noise is not the only type of noise that can have a malign impact on public health. Several other sources of noise such as industrial or occupational need to be taken into account to have a complete consideration of noise into LCA. Major life cycle inventories (LCI) typically do not contain data on noise emissions yet and characterisation factors are not yet clearly defined. The aim of the present paper is to briefly review what is already available in the field and propose a new framework for the consideration of human health impacts of any type of noise that could be of interest in the LCA practice, providing indications for the introduction of noise in LCI and analysing what data is already available and, in the form of a research agenda, what other resources would be needed to reach a complete coverage of the problem. The literature production related to the impacts of noise on human health has been analysed, with considerations of impacts caused by transportation noise as well as occupational and industrial noise. The analysis of the specialist medical literature allowed for a better understanding of how to deal with the epidemiological findings from an LCA perspective and identify areas still missing dose-response relations. A short review of the state-of-science in the field of noise and LCA is presented with an expansion to other contributions in the field subsequent to the comprehensive work by Althaus et al. (2009a; 2009b). Focusing on the analogy between toxicological analysis of pollutants and noise impact evaluation, an alternative approach is suggested, which is oriented to the consideration of any type of noise in LCA and not solely of transportation noise. A multi-step framework is presented as a method for the inclusion of noise impacts on human health in LCA. A theoretical structural framework for the inclusion of noise impacts in LCA is provided as a basis for future modelling expansions in the field. Rather than evaluating traffic/transportation noise, the method focuses on the consideration of the noise level and its impact on human health, regardless of the source producing the noise in an analogous manner as considered in the fields of toxicology and common noise evaluation practices combined. The resulting framework will constitute the basis for the development of a more detailed mathematical model for the inclusion of noise in LCA. The toxicological background and the experience of the analysis of the release of chemicals in LCA seem to provide sufficient ground for the inclusion of noise in LCA: taken into account the physical differences and the uniqueness of noise as an impact, the procedure applied to the release of chemicals during a product life cycle is key for a valuable inclusion of noise in the LCA logic. It is fundamental for the development of research in the field of LCA and noise to consider any type of noise. Further studies are needed to contribute to the inclusion of noise sources and noise impacts in LCA. In this paper, a structure is proposed that will be expanded and adapted in the future and which forms the basic framework for the successive modelling phase.

Do physical abuse, depression, and parental substance use influence patterns of substance use among child welfare involved youth? Substance use misuse.

PubMed

Snyder, Susan M; Smith, Rachel E

2015-01-01

To date studies have not explored patterns of substance use exclusively among youth in the child welfare system. Consequently, little is known about polysubstance use among child welfare-involved youth. This study aimed to explore whether physical abuse, parental substance use, depression, and demographic characteristics predict distinct patterns of substance use among child welfare-involved youth using latent class analysis (LCA). The sample included 822 11-17 year olds who participated in the National Survey of Child and Adolescent Well-being (NSCAW II) study between March 2008 and September 2009. We found the following three classes: (1) polysubstance use, (2) alcohol and marijuana use, and (3) low use. Older youth and youth who experienced physical abuse were at greater risk of being in the polysubstance use class, while living with a biological parent reduced the likelihood of polysubstance use class membership. Youth in the alcohol and marijuana use class were more likely to be older and depressed. Results from this study illuminate important targets for interventions.

Impulse Control and Callous-Unemotional Traits Distinguish Patterns of Delinquency and Substance Use in Justice Involved Adolescents: Examining the Moderating Role of Neighborhood Context.

PubMed

Ray, James V; Thornton, Laura C; Frick, Paul J; Steinberg, Laurence; Cauffman, Elizabeth

2016-04-01

Both callous-unemotional (CU) traits and impulse control are known risk factors associated with delinquency and substance use. However, research is limited in how contextual factors such as neighborhood conditions influence the associations between these two dispositional factors and these two externalizing behaviors. The current study utilized latent class analysis (LCA) to identify unique classes of delinquency and substance use within an ethnically diverse sample (n = 1216) of justice-involved adolescents (ages 13 to 17) from three different sites. Neighborhood disorder, CU traits, and impulse control were all independently associated with membership in classes with more extensive histories of delinquency and substance use. The effects of CU traits and impulse control in distinguishing delinquent classes was invariant across levels of neighborhood disorder, whereas neighborhood disorder moderated the association between impulse control and substance use. Specifically, the probability of being in more severe substance using classes for those low in impulse control was stronger in neighborhoods with fewer indicators of social and physical disorder.

[Latent Class Analysis of Gambling Activities among Korean Adolescents].

PubMed

Kang, Kyonghwa; Kim, Hyeongsu; Park, Ae Ran; Kim, Hee Young; Lee, Kunsei

2018-04-01

The aim of this study is to identify the types of gambling among adolescents and provide basic prevention information regarding adolescents' gambling problems. Secondary data from representative national survey on 2015 Youth Gambling Problems of Korea Center on Gambling Problems were used. Using latent class analysis (LCA), 13 gambling types such as offline and online games of 14,011 adolescents were classified, and gambling experiences and characteristics were analyzed. The subgroups of adolescent gambling were identified as four latent classes: a rare group (84.5% of the sample), a risk group (1.0%), an offline group (11.9%), and an expanded group (2.6%). The types and characteristics of gambling among the latent classes differed. In the risk group, adolescents participated in online illegal sports betting and internet casino, and gambling time, gambling expenses, and the number of gambling types were higher than other groups. Gambling frequently occur among adolescent, and the subtypes of gambling did not reveal homogeneous characteristics. In order to prevent adolescent gambling problems, it is a necessary to develop tailored prevention intervention in the nursing field, which is appropriate to the characteristics of adolescent gambling group and can help with early identification. © 2018 Korean Society of Nursing Science.

LCA to choose among alternative design solutions: the case study of a new Italian incineration line.

PubMed

Scipioni, A; Mazzi, A; Niero, M; Boatto, T

2009-09-01

At international level LCA is being increasingly used to objectively evaluate the performances of different Municipal Solid Waste (MSW) management solutions. One of the more important waste management options concerns MSW incineration. LCA is usually applied to existing incineration plants. In this study LCA methodology was applied to a new Italian incineration line, to facilitate the prediction, during the design phase, of its potential environmental impacts in terms of damage to human health, ecosystem quality and consumption of resources. The aim of the study was to analyse three different design alternatives: an incineration system with dry flue gas cleaning (without- and with-energy recovery) and one with wet flue gas cleaning. The last two technological solutions both incorporating facilities for energy recovery were compared. From the results of the study, the system with energy recovery and dry flue gas cleaning revealed lower environmental impacts in relation to the ecosystem quality. As LCA results are greatly affected by uncertainties of different types, the second part of the work provides for an uncertainty analysis aimed at detecting the extent output data from life cycle analysis are influenced by uncertainty of input data, and employs both qualitative (pedigree matrix) and quantitative methods (Monte Carlo analysis).

A latent class analysis of substance use and culture among gay, bisexual and other men who have sex with men.

PubMed

Card, Kiffer G; Armstrong, Heather L; Carter, Allison; Cui, Zishan; Wang, Lu; Zhu, Julia; Lachowsky, Nathan J; Moore, David M; Hogg, Robert S; Roth, Eric A

2018-03-28

Assessments of gay and bisexual men's substance use often obscures salient sociocultural and identity-related experiences related to how they use drugs. Latent class analysis was used to examine how patterns of substance use represent the social, economic and identity-related experiences of this population. Participants were sexually active gay and bisexual men (including other men who have sex with men), aged ≥ 16 years, living in Metro Vancouver (n = 774). LCA indicators included all substances used in the past six months self-reported by more than 30 men. Model selection was made with consideration to model parsimony, interpretability and optimisation of statistical criteria. Multinomial regression identified factors associated with class membership. A six-class solution was identified representing: 'assorted drug use' (4.5%); 'club drug use' (9.5%); 'street drug use' (12.1%); 'sex drug use' (11.4%); 'conventional drug use' (i.e. tobacco, alcohol, marijuana; 25.9%); and 'limited drug use' (36.7%). Factors associated with class membership included age, sexual orientation, annual income, occupation, income from drug sales, housing stability, group sex event participation, gay bars/clubs attendance, sensation seeking and escape motivation. These results highlight the need for programmes and policies that seek to lessen social disparities and account for social distinctions among this population.

Nested polymerase chain reaction on blood clots for gene encoding 56 kDa antigen and serology for the diagnosis of scrub typhus.

PubMed

Prakash, J A J; Kavitha, M L; Mathai, E

2011-01-01

Scrub typhus is a zoonotic illness endemic in the Asia-Pacific region. Early diagnosis and appropriate management contribute significantly to preventing adverse outcomes including mortality. Serology is widely used for diagnosing scrub typhus. Recent reports suggest that polymerase chain reaction (PCR) could be a rapid and reliable alternative. This study assessed the utility of these tests for scrub typhus diagnosis. Nested PCR to detect the 56 kDa antigen gene of O. tsutsugamushi was performed on blood clots from 87 individuals with clinically suspected scrub typhus. Weil-Felix test and scrub typhus IgM ELISA were performed on serum samples from the same patients. As a gold standard reference test was not available, latent class analysis (LCA) was used to assess the performance of the three tests. The LCA analysis showed the sensitivity of Weil-Felix test, IgM ELISA and PCR to be 59%, 100% and 58% respectively. The specificity of ELISA was only 73%, whereas those of the Weil-Felix test and PCR were 94% and 100% respectively. Nested PCR using blood clots while specific, lacked sensitivity as compared to IgM ELISA. In resource-poor settings Weil-Felix test still remains valuable despite its moderate sensitivity.

Dynamic hybrid life cycle assessment of energy and carbon of multicrystalline silicon photovoltaic systems.

PubMed

Zhai, Pei; Williams, Eric D

2010-10-15

This paper advances the life cycle assessment (LCA) of photovoltaic systems by expanding the boundary of the included processes using hybrid LCA and accounting for the technology-driven dynamics of embodied energy and carbon emissions. Hybrid LCA is an extended method that combines bottom-up process-sum and top-down economic input-output (EIO) methods. In 2007, the embodied energy was 4354 MJ/m(2) and the energy payback time (EPBT) was 2.2 years for a multicrystalline silicon PV system under 1700 kWh/m(2)/yr of solar radiation. These results are higher than those of process-sum LCA by approximately 60%, indicating that processes excluded in process-sum LCA, such as transportation, are significant. Even though PV is a low-carbon technology, the difference between hybrid and process-sum results for 10% penetration of PV in the U.S. electrical grid is 0.13% of total current grid emissions. Extending LCA from the process-sum to hybrid analysis makes a significant difference. Dynamics are characterized through a retrospective analysis and future outlook for PV manufacturing from 2001 to 2011. During this decade, the embodied carbon fell substantially, from 60 g CO(2)/kWh in 2001 to 21 g/kWh in 2011, indicating that technological progress is realizing reductions in embodied environmental impacts as well as lower module price.

Holistic Evaluation of Decentralized Water Reuse: Life Cycle Assessment and Cost Analysis of Membrane Bioreactor Systems in Water Reuse Implementation

EPA Science Inventory

Understand environmental and cost impacts of transitional decentralized MBR systems with sewer mining Assess aerobic MBRs (AeMBR) and anaerobic MBRs (AnMBR) Use LCA and life cycle cost (LCC) analysis to quantify impacts Investigate LCA and LCC performance of MBRs under various re...

Multiple Chronic Conditions and Hospitalizations Among Recipients of Long-Term Services and Supports

PubMed Central

Van Cleave, Janet H.; Egleston, Brian L.; Abbott, Katherine M.; Hirschman, Karen B.; Rao, Aditi; Naylor, Mary D.

2016-01-01

Background Among older adults receiving long term-services and supports (LTSS), debilitating hospitalizations is a pervasive clinical and research problem. Multiple chronic conditions (MCC) are prevalent in LTSS recipients. However, the combination of MCC and diseases associated with hospitalizations of LTSS recipients is unclear. Objective The purpose of this analysis was to determine the association between classes of MCC in newly enrolled LTSS recipients and the number of hospitalizations over a one-year period following enrollment. Methods This report is based on secondary analysis of extant data from a longitudinal cohort study of 470 new recipients of LTSS, ages 60 years and older, receiving services in assisted living facilities, nursing homes, or through home- and community-based services. Using baseline chronic conditions reported in medical records, latent class analysis (LCA) was used to identify classes of MCC and posterior probabilities of membership in each class. Poisson regressions were used to estimate the relative ratio between posterior probabilities of class membership and number of hospitalizations during the 3 month period prior to the start of LTSS (baseline) and then every three months forward through 12 months. Results Three latent MCC-based classes named Cardiopulmonary, Cerebrovascular/Paralysis, and All Other Conditions were identified. The Cardiopulmonary class was associated with elevated numbers of hospitalization compared to the All Other Conditions class (relative ratio [RR] = 1.88, 95% CI [1.33, 2.65], p < .001). Conclusion Older LTSS recipients with a combination of MCCs that includes cardiopulmonary conditions have increased risk for hospitalization. PMID:27801713

What do we know about child abuse and neglect patterns of co-occurrence? A systematic review of profiling studies and recommendations for future research.

PubMed

Debowska, Agata; Willmott, Dominic; Boduszek, Daniel; Jones, Adele D

2017-08-01

Latent class (LCA) and latent profile (LPA) analysis represent methodological approaches to identify subgroups of maltreated individuals. Although research examining child abuse and neglect (CAN) profiles is still rare, the application of person-centered techniques to clarify CAN types co-occurrence has substantially increased in recent years. Therefore, the aim of the present study was to provide a summary and critical evaluation of the findings of LCA/LPA child maltreatment research to: (a) systemize the current understanding of patterns of maltreatment across populations and (b) elucidate interactive effects of CAN types on psychosocial functioning. A search in PsychInfo, Eric, PubMed, Scopus, and Science Direct, and Google Scholar was performed. Sixteen studies examining the co-occurrence between child physical abuse, emotional abuse, sexual abuse, neglect, and/or exposure to domestic violence were identified. A critical review of the studies revealed inconsistent findings as to the number of CAN classes, but most research uncovered a poly-victimized and a low abuse group. Further, multiple victimization was associated with most adverse internalizing and externalizing outcomes, especially when sexual abuse was present. Exposure to physical and emotional abuse was frequently reported to lead to behavioural problems. Based on the present study results, we provide a set of recommendations for surpassing the current methodological and conceptual limitations in future research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Early Lapses in a Cessation Attempt: Lapse Contexts, Cessation Success, and Predictors of Early Lapse

PubMed Central

2013-01-01

Introduction: The great majority of smokers relapse when they make quit attempts. Therefore, understanding the process of relapse may guide the development of more effective smoking cessation or relapse prevention treatments. The goal of this research is to extend our understanding of the context of initial lapses that occur within 8 weeks of quitting by using more comprehensive assessments of context, a contemporary sample, and sophisticated analytic techniques. Methods: Participants from a randomized controlled smoking cessation trial completed baseline assessments of demographics and tobacco dependence, a daily smoking calendar to determine latency to lapse and relapse (7 consecutive days of smoking), and an assessment of initial lapse context (affect, location, activity, interpersonal, smoke exposure, and cigarette availability). Latent class analysis (LCA) was used to analyze the 6 early lapse (within the first 8 weeks; N = 551) context dimensions; logistic regression and Cox regression were used to relate context to cessation outcomes. Results: LCA revealed 5 distinct initial lapse context classes (talking, with friends, angry; social; alone; with spouse, angry; and with smoking spouse) that were differentially related to cessation outcome. The easy availability of cigarettes characterized almost 75% of lapses, but being with friends, drinking, and not being at home were associated with a lower likelihood of progression to relapse. Conclusions: Early lapsing is highly related to ultimate relapse, and lapsing in frequently experienced contexts seemed most strongly linked with progression to full relapse. PMID:23780705

Analysis and Assessment of Environmental Load of Vending Machines by a LCA Method, and Eco-Improvement Effect

NASA Astrophysics Data System (ADS)

Kimura, Yukio; Sadamichi, Yucho; Maruyama, Naoki; Kato, Seizo

These days the environmental impact due to vending machines'(VM) diffusion has greatly been discussed. This paper describes the numerical evaluation of the environmental impact by using the LCA (Life Cycle Assessment) scheme and then proposes eco-improvements' strategy toward environmentally conscious products(ECP). A new objective and universal consolidated method for the LCA-evaluation, so-called LCA-NETS(Numerical Eco-load Standardization ) developed by the authors is applied to the present issue. As a result, the environmental loads at the 5years' operation and the material procurement stages are found to dominate others over the life cycle. Further eco-improvement is realized by following the order of the LCA-NETS magnitude; namely, energy saving, materials reducing, parts' re-using, and replacing with low environmental load material. Above all, parts' re-using is specially recommendable for significant reduction of the environmental loads toward ECP.

Differential factors associated with challenge-proven food allergy phenotypes in a population cohort of infants: a latent class analysis.

PubMed

Peters, R L; Allen, K J; Dharmage, S C; Lodge, C J; Koplin, J J; Ponsonby, A-L; Wake, M; Lowe, A J; Tang, M L K; Matheson, M C; Gurrin, L C

2015-05-01

Food allergy, eczema and wheeze are early manifestations of allergic disease and commonly co-occur in infancy although their interrelationship is not well understood. Data from population studies are essential to determine whether there are differential drivers of multi-allergy phenotypes. We aimed to define phenotypes and risk factors of allergic disease using latent class analysis (LCA). The HealthNuts study is a prospective, population-based cohort of 5276 12-month-old infants in Melbourne, Australia. LCA was performed using the following baseline data collected at age 12 months: food sensitization (skin prick test ≥ 2 mm) and allergy (oral food challenge) to egg, peanut and sesame; early (< 4 months) and late-onset eczema; and wheeze in the first year of life. Risk factors were modelled using multinomial logistic regression. Five distinct phenotypes were identified: no allergic disease (70%), non-food-sensitized eczema (16%), single egg allergy (9%), multiple food allergies (predominantly peanut) (3%) and multiple food allergies (predominantly egg) (2%). Compared to the baseline group of no allergic disease, shared risk factors for all allergic phenotypes were parents born overseas (particularly Asia), delayed introduction of egg, male gender (except for single egg allergy) and family history of allergic disease, whilst exposure to pet dogs was protective for all phenotypes. Other factors including filaggrin mutations, vitamin D and the presence of older siblings differed by phenotype. Multiple outcomes in infancy can be used to determine five distinct allergy phenotypes at the population level, which have both shared and separate risk factors suggesting differential mechanisms of disease. © 2014 John Wiley & Sons Ltd.

Area of Concern: a new paradigm in life cycle assessment for the development of footprint metrics

EPA Science Inventory

Purpose: As a class of environmental metrics, footprints have been poorly defined, have shared an unclear relationship to life cycle assessment (LCA), and the variety of approaches to quantification have sometimes resulted in confusing and contradictory messages in the marketplac...

Environmental life cycle assessment of methanol and electricity co-production system based on coal gasification technology.

PubMed

Śliwińska, Anna; Burchart-Korol, Dorota; Smoliński, Adam

2017-01-01

This paper presents a life cycle assessment (LCA) of greenhouse gas emissions generated through methanol and electricity co-production system based on coal gasification technology. The analysis focuses on polygeneration technologies from which two products are produced, and thus, issues related to an allocation procedure for LCA are addressed in this paper. In the LCA, two methods were used: a 'system expansion' method based on two approaches, the 'avoided burdens approach' and 'direct system enlargement' methods and an 'allocation' method involving proportional partitioning based on physical relationships in a technological process. Cause-effect relationships in the analysed production process were identified, allowing for the identification of allocation factors. The 'system expansion' method involved expanding the analysis to include five additional variants of electricity production technologies in Poland (alternative technologies). This method revealed environmental consequences of implementation for the analysed technologies. It was found that the LCA of polygeneration technologies based on the 'system expansion' method generated a more complete source of information on environmental consequences than the 'allocation' method. The analysis shows that alternative technologies chosen for generating LCA results are crucial. Life cycle assessment was performed for the analysed, reference and variant alternative technologies. Comparative analysis was performed between the analysed technologies of methanol and electricity co-production from coal gasification as well as a reference technology of methanol production from the natural gas reforming process. Copyright © 2016 Elsevier B.V. All rights reserved.

Mental health correlates of victimization classes among homeless youth.

PubMed

Bender, Kimberly; Ferguson, Kristin; Thompson, Sanna; Langenderfer, Lisa

2014-10-01

Literature reports high rates of street victimization among homeless youth and recognizes psychiatric symptoms associated with such victimization. Few studies have investigated the existence of victimization classes that differ in type and frequency of victimization and how youth in such classes differ in psychiatric profiles. We used latent class analysis (LCA) to examine whether classes of homeless youth, based on both type and frequency of victimization experiences, differ in rates of meeting diagnostic criteria for major depressive episodes and posttraumatic stress disorder (PTSD) in a sample of homeless youth (N=601) from three regions of the United States. Results suggest youth who experience high levels of direct and indirect victimization (high-victimization class) share similarly high rates of depressive episodes and PTSD as youth who experience primarily indirect victimization only (witness class). Rates of meeting criteria for depressive episodes and PTSD were nearly two and three times greater, respectively, among the high victimization and witness classes compared to youth who never or rarely experienced victimization. Findings suggest the need for screening and intervention for homeless youth who report direct and indirect victimization and youth who report indirect victimization only, while prevention efforts may be more relevant for youth who report limited victimization experience. Copyright © 2014 Elsevier Ltd. All rights reserved.

Life cycle assessment and residue leaching: the importance of parameter, scenario and leaching data selection.

PubMed

Allegrini, E; Butera, S; Kosson, D S; Van Zomeren, A; Van der Sloot, H A; Astrup, T F

2015-04-01

Residues from industrial processes and waste management systems (WMSs) have been increasingly reutilised, leading to landfilling rate reductions and the optimisation of mineral resource utilisation in society. Life cycle assessment (LCA) is a holistic methodology allowing for the analysis of systems and products and can be applied to waste management systems to identify environmental benefits and critical aspects thereof. From an LCA perspective, residue utilisation provides benefits such as avoiding the production and depletion of primary materials, but it can lead to environmental burdens, due to the potential leaching of toxic substances. In waste LCA studies where residue utilisation is included, leaching has generally been neglected. In this study, municipal solid waste incineration bottom ash (MSWI BA) was used as a case study into three LCA scenarios having different system boundaries. The importance of data quality and parameter selection in the overall LCA results was evaluated, and an innovative method to assess metal transport into the environment was applied, in order to determine emissions to the soil and water compartments for use in an LCA. It was found that toxic impacts as a result of leaching were dominant in systems including only MSWI BA utilisation, while leaching appeared negligible in larger scenarios including the entire waste system. However, leaching could not be disregarded a priori, due to large uncertainties characterising other activities in the scenario (e.g. electricity production). Based on the analysis of relevant parameters relative to leaching, and on general results of the study, recommendations are provided regarding the use of leaching data in LCA studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

Packed-column capillary electrochromatography and capillary electrochromatography-mass spectrometry using a lithocholic acid stationary phase

PubMed Central

Norton, Dean; Shamsi, Shahab A.

2009-01-01

The preparation and characterization of a novel lithocholic acid (LCA)-based liquid crystalline (LC) stationary phase (SP) suitable for application in packed-column CEC and CEC coupled to MS is described. The extent of bonding reactions of LCA-SP was assessed using 1H-NMR, 13C-NMR and elemental analysis. This characterization is followed by application of the LCA-SP for separation of β-blockers, phenylethylamines (PEAs), polyaromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Using the optimum mobile phase operating conditions (pH 3.0-4.5, 10 mM ammonium acetate, 85% v/v ACN), a comparison of the chromatographic ability of the aminopropyl silica phase vs. the LCA-bonded phase was conducted. The results showed improved selectivity for all test analytes using the latter phase. For example, the CEC-MS of β-blockers demonstrated that the LCA-bonded phase provides separation of six out of seven β-blockers, whereas the amino silica phase provides four peaks of several co-eluting β-blockers. For the CEC-MS analysis of PEAs, the LCA-bonded phase showed improved resolution and different selectivity as compared to the aminopropyl phase. An evaluation of the retention trends for PEAs on both phases suggested that the PEAs were retained based on varying degree of hydroxyl substitution on the aromatic ring. In addition, the MS characterization shows several PEAs fragment in the electrospray either by loss of an alkyl group and/or by loss of H2O. Finally, the LCA-bonded phase displayed significantly higher separation selectivity for PAHs and PCBs as compared to the amino silica phase. PMID:18425746

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

Frischknecht, Rolf; Heath, Garvin; Raugei, Marco

Life Cycle Assessment (LCA) is a structured, comprehensive method of quantifying material- and energy-flows and their associated emissions caused in the life cycle of goods and services. The ISO 14040 and 14044 standards provide the framework for LCA. However, this framework leaves the individual practitioner with a range of choices that can affect the results and thus the conclusions of an LCA study. The current IEA guidelines were developed to provide guidance on assuring consistency, balance, and quality to enhance the credibility and reliability of the results from LCAs on photovoltaic (PV) electricity generation systems. The guidelines represent a consensusmore » among the authors - PV LCA experts in North America, Europe, and Asia - for assumptions made on PV performance, decisions on process input and emissions allocation, methods of analysis, and reporting of the results. Guidance is given on PV-specific parameters used as inputs in LCA and on choices and assumptions in life cycle inventory (LCI) data analysis and on implementation of modeling approaches. A consistent approach towards system modeling, the functional unit, the system boundaries, water use modeling and the allocation aspects enhances the credibility of PV electricity LCA studies and enables balanced LCA-based comparisons of different electricity producing technologies. The document discusses metrics like greenhouse gas emissions (GHG), cumulative energy demand (CED), acidification potential (AP), ozone depletion potential (ODP), human toxicity, ecotoxicity and ionizing radiation. Guidance is given for the definition of the energy payback time (EPBT), the nonrenewable energy payback time (NREPBT), and the impact mitigation potentials (IMP). The indicator energy return on investment (EROI) is described in a separate International Energy Agency (IEA) PV Power Systems (PVPS) Task 12 report (Raugei et al. 2015). The guidelines on the reporting and communication of the results serve the need for producing clear, comprehensive and transparent reports.« less

Established risk factors for addiction fail to discriminate between healthy gamers and gamers endorsing DSM-5 Internet gaming disorder.

PubMed

Deleuze, Jory; Nuyens, Filip; Rochat, Lucien; Rothen, Stéphane; Maurage, Pierre; Billieux, Joël

2017-12-01

Background and aims The DSM-5 includes criteria for diagnosing Internet gaming disorder (IGD) that are adapted from substance abuse and widely used in research and clinical contexts, although evidence supporting their validity remains scarce. This study compared online gamers who do or do not endorse IGD criteria regarding self-control-related abilities (impulsivity, inhibitory control, and decision-making), considered the hallmarks of addictive behaviors. Method A double approach was adopted to distinguish pathological from recreational gamers: The first is the classic DSM-5 approach (≥5 criteria required to endorse the IGD diagnosis), and the second consists in using latent class analysis (LCA) for IGD criteria to distinguish gamers' subgroups. We computed comparisons separately for each approach. Ninety-seven volunteer gamers from the community were recruited. Self-reported questionnaires were used to measure demographic- and game-related characteristics, problematic online gaming (with the Problematic Online Gaming Questionnaire), impulsivity (with the UPPS-P Impulsive Behavior Scale), and depression (with the Beck Depression Inventory-II). Experimental tasks were used to measure inhibitory control (Hybrid-Stop Task) and decision-making abilities (Game of Dice Task). Results Thirty-two participants met IGD criteria (33% of the sample), whereas LCA identified two groups of gamers [pathological (35%) and recreational]. Comparisons that used both approaches (DSM-5 and LCA) failed to identify significant differences regarding all constructs except for variables related to actual or problematic gaming behaviors. Discussion The validity of IGD criteria is questioned, mostly with respect to their relevance in distinguishing high engagement from pathological involvement in video games.

Medulloblastoma: histopathologic and molecular markers of anaplasia and biologic behavior.

PubMed

Min, Hye Sook; Lee, You Jeong; Park, Kyeongmee; Cho, Byung-Kyu; Park, Sung-Hye

2006-07-01

Large cell/anaplastic (LC/A) medulloblastoma (MB) is a recently recognized variant of medulloblastoma known to be associated with an advanced stage and a poor prognosis. Although Eberhart et al. suggested histopathologic grading of medulloblastoma in 2002, no consensus has been reached in terms of determining the criteria of an LC/A variant, and its biological behavior continues to be the subject of debate. We retrospectively analyzed 74 cases (range 0.25-15 years) of MB clinicopathologically using the criteria established by Eberhart et al. The LC/A variant was identified in 16 cases (22% of MB cases), five of which showed a poor outcome. Most LC/A variant cases revealed synaptophysin immunoexpression (75%), but no epidermal growth factor receptor (EGFR) expression. Expression of synaptophysin, NeuN, GFAP, p53, c-erbB2, and EGFR did not differ in LC/A and non-LC/A variants. Seven of the 74 cases of medulloblastoma showed erbB2 amplification by FISH, four of which were LC/A variants. N-myc amplification was observed in only one LC/A variant, but no c-myc amplification was found. In patients younger than 10 years, the LC/A variant showed a significantly poorer outcome than the non-LC/A variant (P = 0.02), while no difference was found in older patients. Multivariate analysis revealed only metastasis on MRI and p53 expression, but not anaplasia as unfavorable prognostic factors. Our study suggests that prognostic implications of anaplasia in medulloblastoma are uncertain, and that the reproducibility of the histopathologic criteria of the LC/A variant should be reassessed before they can be applied in practical use.

Patterns of dietary habits in relation to obesity in Iranian adults.

PubMed

Saneei, Parvane; Esmaillzadeh, Ahmad; Keshteli, Ammar Hassanzadeh; Feizi, Awat; Feinle-Bisset, Christine; Adibi, Peyman

2016-03-01

Findings from few studies that investigated the relation between dietary behaviors and obesity are inconsistent. We aimed to assess the relation between patterns of dietary habits, identified by latent class analysis (LCA), and obesity in a large sample of Iranian adults. In a cross-sectional study on 7958 adults, dietary behaviors were assessed in five domains (meal patterns, eating rate, intra-meal fluid intake, meal-to-sleep interval, and fatty foods intake) using a pretested questionnaire. LCA was applied to identify classes of diet-related practices. Anthropometric measures were assessed through the use of a validated self-reported questionnaire. General and abdominal obesity were defined as a body mass index ≥ 30 kg/m(2), and a waist circumference ≥ 88 cm for women and ≥ 102 cm for men. General and abdominal obesity were prevalent in 9.7 and 27.7 % of the study population, respectively. We identified three distinct classes of eating rates (moderate, moderate to slow, and moderate to fast), two classes of meal patterns (regular and irregular), two classes of intra-meal fluid intake (moderate and more intra-meal drinking), three classes of meal-to-sleep interval (short, moderate, and long meal-to-sleep interval), and three classes of fatty food intake (low to moderate, moderate to high, and low intake of fatty foods). After adjustment for potential confounders, individuals with 'irregular meal pattern' were 21, 24, and 22 % more likely to be overweight/obese, abdominally overweight/obese, and abdominally obese, compared with those who had a 'regular meal pattern.' Individuals with 'more intra-meal drinking' had greater odds of overweight (OR 1.37; 1.19-1.458) and obesity (OR 1.51; 1.16-1.97) than those with 'moderate intra-meal drinking.' Moderate-to-high intake of fatty foods was inversely associated with abdominally overweight/obese (OR 0.85; 0.73-1.00) and abdominally obesity (OR 0.80; 0.68-0.96) compared with 'low-to-moderate intake of fatty foods.' No significant association was observed between eating rate, meal-to-sleep interval, and general or abdominal obesity, after controlling for confounders. Irregular meal pattern and more intra-meal drinking were associated with increased odds of general and abdominal obesity, whereas moderate-to-high intake of fatty foods was related to the decreased odds of central obesity among Iranian adults.

Sleep disturbances in young and middle-aged adults - Empirical patterns and related factors from an epidemiological survey.

PubMed

Rössler, Wulf; AjdacicGross, Vladeta; Glozier, Nick; Rodgers, Stephanie; Haker, Helene; Müller, Mario

2017-10-01

Previous research suggests that sleep disorders are highly associated with other mental health problems. However, sleep problems even below the diagnostic threshold of sleep disorders are very common in the general population, which highly affects wellbeing and functioning. In order to broaden the focus beyond those severe cases we explored empirical patterns across the whole spectrum of sleep problems as well as associated clinical and other factors. A representative community sample of N=1274 residents from the canton of Zurich was interviewed for sleep problems and diagnostic criteria for mental disorders as well as was given a number of mental health-related psychometrical checklists. Based on a broader spectrum of sleep problems we conducted a latent class analysis (LCA) to derive distinct classes of such disturbances. Classes were compared regarding their associations to mental health-relevant and other risk factors. The LCA revealed four classes - no sleep disturbances (72.6%), difficulties initiating and maintaining sleep (15.8%), delayed sleep (5.3%), and severe sleep problems (6.4%). Severe sleep problems were related to female gender and generalized anxiety disorder, while depression was linked to all sleep problem classes. Persons with difficulties initiating and maintaining sleep and severe sleep problems reported higher levels of psychopathology, burnout and neuroticism, while all sleep problem types were tied to stress-related variables, but not alcohol use disorder. Sleep problems are highly prevalent among the young and middle-aged adults in our representative sample of young and middle-aged adults and as such represent a serious public mental health problem. Our findings indicate sleep problems to have a multi-dimensional structure with some differential associations. While all subtypes were associated with poorer mental health and particularly more depression, severe sleep problems appeared to be the sleep subtype seen in agoraphobia and GAD, while delayed sleep had no specific associations. The variety of associations assessed leads one to assume that likewise a variety of sleep interventions is required. Copyright © 2017 Elsevier Inc. All rights reserved.

Assessing Resource Intensity and Renewability of Cellulosic Ethanol Technologies using Eco-LCA

EPA Science Inventory

Recognizing the contributions of natural resources and the lack of their comprehensive accounting in life cycle assessment (LCA) of cellulosic ethanol, an in-depth analysis of the contribution of natural resources in the life cycle of cellulosic ethanol derived from five differen...

Latent classes of emotional and behavioural problems in epidemiological and referred samples and their relations to DSM-IV diagnoses.

PubMed

Bianchi, Valentina; Brambilla, Paolo; Garzitto, Marco; Colombo, Paola; Fornasari, Livia; Bellina, Monica; Bonivento, Carolina; Tesei, Alessandra; Piccin, Sara; Conte, Stefania; Perna, Giampaolo; Frigerio, Alessandra; Castiglioni, Isabella; Fabbro, Franco; Molteni, Massimo; Nobile, Maria

2017-05-01

Researchers' interest have recently moved toward the identification of recurrent psychopathological profiles characterized by concurrent elevations on different behavioural and emotional traits. This new strategy turned to be useful in terms of diagnosis and outcome prediction. We used a person-centred statistical approach to examine whether different groups could be identified in a referred sample and in a general-population sample of children and adolescents, and we investigated their relation to DSM-IV diagnoses. A latent class analysis (LCA) was performed on the Child Behaviour Checklist (CBCL) syndrome scales of the referred sample (N = 1225), of the general-population sample (N = 3418), and of the total sample. Models estimating 1-class through 5-class solutions were compared and agreement in the classification of subjects was evaluated. Chi square analyses, a logistic regression, and a multinomial logistic regression analysis were used to investigate the relations between classes and diagnoses. In the two samples and in the total sample, the best-fitting models were 4-class solutions. The identified classes were Internalizing Problems (15.68%), Severe Dysregulated (7.82%), Attention/Hyperactivity (10.19%), and Low Problems (66.32%). Subsequent analyses indicated a significant relationship between diagnoses and classes as well as a main association between the severe dysregulated class and comorbidity. Our data suggested the presence of four different psychopathological profiles related to different outcomes in terms of psychopathological diagnoses. In particular, our results underline the presence of a profile characterized by severe emotional and behavioural dysregulation that is mostly associated with the presence of multiple diagnosis.

Analysis and Compensation for Lateral Chromatic Aberration in a Color Coding Structured Light 3D Measurement System.

PubMed

Huang, Junhui; Xue, Qi; Wang, Zhao; Gao, Jianmin

2016-09-03

While color-coding methods have improved the measuring efficiency of a structured light three-dimensional (3D) measurement system, they decreased the measuring accuracy significantly due to lateral chromatic aberration (LCA). In this study, the LCA in a structured light measurement system is analyzed, and a method is proposed to compensate the error caused by the LCA. Firstly, based on the projective transformation, a 3D error map of LCA is constructed in the projector images by using a flat board and comparing the image coordinates of red, green and blue circles with the coordinates of white circles at preselected sample points within the measurement volume. The 3D map consists of the errors, which are the equivalent errors caused by LCA of the camera and projector. Then in measurements, error values of LCA are calculated and compensated to correct the projector image coordinates through the 3D error map and a tri-linear interpolation method. Eventually, 3D coordinates with higher accuracy are re-calculated according to the compensated image coordinates. The effectiveness of the proposed method is verified in the following experiments.

Analysis and Compensation for Lateral Chromatic Aberration in a Color Coding Structured Light 3D Measurement System

PubMed Central

Huang, Junhui; Xue, Qi; Wang, Zhao; Gao, Jianmin

2016-01-01

While color-coding methods have improved the measuring efficiency of a structured light three-dimensional (3D) measurement system, they decreased the measuring accuracy significantly due to lateral chromatic aberration (LCA). In this study, the LCA in a structured light measurement system is analyzed, and a method is proposed to compensate the error caused by the LCA. Firstly, based on the projective transformation, a 3D error map of LCA is constructed in the projector images by using a flat board and comparing the image coordinates of red, green and blue circles with the coordinates of white circles at preselected sample points within the measurement volume. The 3D map consists of the errors, which are the equivalent errors caused by LCA of the camera and projector. Then in measurements, error values of LCA are calculated and compensated to correct the projector image coordinates through the 3D error map and a tri-linear interpolation method. Eventually, 3D coordinates with higher accuracy are re-calculated according to the compensated image coordinates. The effectiveness of the proposed method is verified in the following experiments. PMID:27598174

The changing nature of life cycle assessment

PubMed Central

McManus, Marcelle C.; Taylor, Caroline M.

2015-01-01

LCA has evolved from its origins in energy analysis in the 1960s and 70s into a wide ranging tool used to determine impacts of products or systems over several environmental and resource issues. The approach has become more prevalent in research, industry and policy. Its use continues to expand as it seeks to encompass impacts as diverse as resource accounting and social well being. Carbon policy for bioenergy has driven many of these changes. Enabling assessment of complex issues over a life cycle basis is beneficial, but the process is sometimes difficult. LCA's use in framing is increasingly complex and more uncertain, and in some cases, irreconcilable. The charged environment surrounding biofuels and bioenergy exacerbates all of these. Reaching its full potential to help guide difficult policy discussions and emerging research involves successfully managing LCA's transition from attributional to consequential and from retrospective to prospective. This paper examines LCA's on-going evolution and its use within bioenergy deployment. The management of methodological growth in the context of the unique challenges associated with bioenergy and biofuels is explored. Changes seen in bioenergy LCA will bleed into other LCA arenas, especially where it is important that a sustainable solution is chosen. PMID:26664146

Life Cycle Assessment for desalination: a review on methodology feasibility and reliability.

PubMed

Zhou, Jin; Chang, Victor W-C; Fane, Anthony G

2014-09-15

As concerns of natural resource depletion and environmental degradation caused by desalination increase, research studies of the environmental sustainability of desalination are growing in importance. Life Cycle Assessment (LCA) is an ISO standardized method and is widely applied to evaluate the environmental performance of desalination. This study reviews more than 30 desalination LCA studies since 2000s and identifies two major issues in need of improvement. The first is feasibility, covering three elements that support the implementation of the LCA to desalination, including accounting methods, supporting databases, and life cycle impact assessment approaches. The second is reliability, addressing three essential aspects that drive uncertainty in results, including the incompleteness of the system boundary, the unrepresentativeness of the database, and the omission of uncertainty analysis. This work can serve as a preliminary LCA reference for desalination specialists, but will also strengthen LCA as an effective method to evaluate the environment footprint of desalination alternatives. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of the GHG Reduction Potential from Energy Crops Using a Combined LCA and Biogeochemical Process Models: A Review

PubMed Central

Jiang, Dong; Hao, Mengmeng; Wang, Qiao; Huang, Yaohuan; Fu, Xinyu

2014-01-01

The main purpose for developing biofuel is to reduce GHG (greenhouse gas) emissions, but the comprehensive environmental impact of such fuels is not clear. Life cycle analysis (LCA), as a complete comprehensive analysis method, has been widely used in bioenergy assessment studies. Great efforts have been directed toward establishing an efficient method for comprehensively estimating the greenhouse gas (GHG) emission reduction potential from the large-scale cultivation of energy plants by combining LCA with ecosystem/biogeochemical process models. LCA presents a general framework for evaluating the energy consumption and GHG emission from energy crop planting, yield acquisition, production, product use, and postprocessing. Meanwhile, ecosystem/biogeochemical process models are adopted to simulate the fluxes and storage of energy, water, carbon, and nitrogen in the soil-plant (energy crops) soil continuum. Although clear progress has been made in recent years, some problems still exist in current studies and should be addressed. This paper reviews the state-of-the-art method for estimating GHG emission reduction through developing energy crops and introduces in detail a new approach for assessing GHG emission reduction by combining LCA with biogeochemical process models. The main achievements of this study along with the problems in current studies are described and discussed. PMID:25045736

The basics of least cost analysis for archaeological applications

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

White, Devin Alan

Here we report that Least Cost Analysis (LCA) is a geospatially focused quantitative approach that can help archaeologists better understand how people may have moved across a landscape. At its core is the assumption that humans make decisions about movement as fully rational actors with complete knowledge of the landscape, attempting to minimize the cost of that movement as they travel from one location to another. LCA is most often used to construct a small number of hypothetical routes between locations of interest and, when used effectively, can even lead to the creation of entire transportation networks. Desktop GIS softwaremore » packages, both commercial and open source, make running LCA relatively straightforward, but that does not necessarily mean that the output is informative or accurate. The following tutorial is designed to expose the reader to the foundational steps required to complete an LCA workflow, along with the scientific rationale behind each step and how to avoid potential pitfalls that one might run into along the way. Finally, relevant literature is cited throughout the tutorial in order to provide context for the technical methods that underpin available tools, to suggest various ways that LCA can be used to solve archaeological problems, and to show the art of the possible.« less

The basics of least cost analysis for archaeological applications

DOE PAGES

White, Devin Alan

2015-11-01

Here we report that Least Cost Analysis (LCA) is a geospatially focused quantitative approach that can help archaeologists better understand how people may have moved across a landscape. At its core is the assumption that humans make decisions about movement as fully rational actors with complete knowledge of the landscape, attempting to minimize the cost of that movement as they travel from one location to another. LCA is most often used to construct a small number of hypothetical routes between locations of interest and, when used effectively, can even lead to the creation of entire transportation networks. Desktop GIS softwaremore » packages, both commercial and open source, make running LCA relatively straightforward, but that does not necessarily mean that the output is informative or accurate. The following tutorial is designed to expose the reader to the foundational steps required to complete an LCA workflow, along with the scientific rationale behind each step and how to avoid potential pitfalls that one might run into along the way. Finally, relevant literature is cited throughout the tutorial in order to provide context for the technical methods that underpin available tools, to suggest various ways that LCA can be used to solve archaeological problems, and to show the art of the possible.« less

Accuracy of parasitological and immunological tests for the screening of human schistosomiasis in immigrants and refugees from African countries: An approach with Latent Class Analysis

PubMed Central

Beltrame, Anna; Guerriero, Massimo; Angheben, Andrea; Gobbi, Federico; Requena-Mendez, Ana; Zammarchi, Lorenzo; Formenti, Fabio; Perandin, Francesca; Bisoffi, Zeno

2017-01-01

Background Schistosomiasis is a neglected infection affecting millions of people, mostly living in sub-Saharan Africa. Morbidity and mortality due to chronic infection are relevant, although schistosomiasis is often clinically silent. Different diagnostic tests have been implemented in order to improve screening and diagnosis, that traditionally rely on parasitological tests with low sensitivity. Aim of this study was to evaluate the accuracy of different tests for the screening of schistosomiasis in African migrants, in a non endemic setting. Methodology/Principal findings A retrospective study was conducted on 373 patients screened at the Centre for Tropical Diseases (CTD) in Negrar, Verona, Italy. Biological samples were tested with: stool/urine microscopy, Circulating Cathodic Antigen (CCA) dipstick test, ELISA, Western blot, immune-chromatographic test (ICT). Test accuracy and predictive values of the immunological tests were assessed primarily on the basis of the results of microscopy (primary reference standard): ICT and WB resulted the test with highest sensitivity (94% and 92%, respectively), with a high NPV (98%). CCA showed the highest specificity (93%), but low sensitivity (48%). The analysis was conducted also using a composite reference standard, CRS (patients classified as infected in case of positive microscopy and/or at least 2 concordant positive immunological tests) and Latent Class Analysis (LCA). The latter two models demonstrated excellent agreement (Cohen’s kappa: 0.92) for the classification of the results. In fact, they both confirmed ICT as the test with the highest sensitivity (96%) and NPV (97%), moreover PPV was reasonably good (78% and 72% according to CRS and LCA, respectively). ELISA resulted the most specific immunological test (over 99%). The ICT appears to be a suitable screening test, even when used alone. Conclusions The rapid test ICT was the most sensitive test, with the potential of being used as a single screening test for African migrants. PMID:28582412

Review of LCA studies of solid waste management systems – Part I: Lessons learned and perspectives

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

Laurent, Alexis, E-mail: alau@dtu.dk; Bakas, Ioannis; Clavreul, Julie

Highlights: • We perform a critical review of 222 LCA studies of solid waste management systems. • Studies mainly concentrated in Europe with little application in developing countries. • Assessments of relevant waste types apart from household waste have been overlooked. • Local specificities of systems prevent a meaningful generalisation of the LCA results. • LCA should support recommendations representative of the local conditions. - Abstract: The continuously increasing solid waste generation worldwide calls for management strategies that integrate concerns for environmental sustainability. By quantifying environmental impacts of systems, life cycle assessment (LCA) is a tool, which can contribute tomore » answer that call. But how, where and to which extent has it been applied to solid waste management systems (SWMSs) until now, and which lessons can be learnt from the findings of these LCA applications? To address these questions, we performed a critical review of 222 published LCA studies of SWMS. We first analysed the geographic distribution and found that the published studies have primarily been concentrated in Europe with little application in developing countries. In terms of technological coverage, they have largely overlooked application of LCA to waste prevention activities and to relevant waste types apart from household waste, e.g. construction and demolition waste. Waste management practitioners are thus encouraged to abridge these gaps in future applications of LCA. In addition to this contextual analysis, we also evaluated the findings of selected studies of good quality and found that there is little agreement in the conclusions among them. The strong dependence of each SWMS on local conditions, such as waste composition or energy system, prevents a meaningful generalisation of the LCA results as we find it in the waste hierarchy. We therefore recommend stakeholders in solid waste management to regard LCA as a tool, which, by its ability of capturing the local specific conditions in the modelling of environmental impacts and benefits of a SWMS, allows identifying critical problems and proposing improvement options adapted to the local specificities.« less

Life Cycle Assessment Software for Product and Process Sustainability Analysis

ERIC Educational Resources Information Center

Vervaeke, Marina

2012-01-01

In recent years, life cycle assessment (LCA), a methodology for assessment of environmental impacts of products and services, has become increasingly important. This methodology is applied by decision makers in industry and policy, product developers, environmental managers, and other non-LCA specialists working on environmental issues in a wide…

Teaching Green Engineering: The Case of Ethanol Lifecycle Analysis

ERIC Educational Resources Information Center

Vallero, Daniel A.; Braiser, Chris

2008-01-01

Lifecycle assessment (LCA) is a valuable tool in teaching green engineering and has been used to assess biofuels, including ethanol. An undergraduate engineering course at Duke University has integrated LCA with other interactive teaching techniques to enhance awareness and to inform engineering decision making related to societal issues, such as…

Lifecycle analysis for automobiles: Uses and limitations

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

Gaines, L.; Stodolsky, F.

There has been a recent trend toward the use of lifecycle analysis (LCA) as a decision-making tool for the automotive industry. However, the different practitioners` methods and assumptions vary widely, as do the interpretations put on the results. The lack of uniformity has been addressed by such groups as the Society of Environmental Toxicology and Chemistry (SETAC) and the International Organization for Standardization (ISO), but standardization of methodology assures neither meaningful results nor appropriate use of the results. This paper examines the types of analysis that are possible for automobiles, explains possible pitfalls to be avoided, and suggests ways thatmore » LCA can be used as part of a rational decision-making procedure. The key to performing a useful analysis is identification of the factors that will actually be used in making the decision. It makes no sense to analyze system energy use in detail if direct financial cost is to be the decision criterion. Criteria may depend on who is making the decision (consumer, producer, regulator). LCA can be used to track system performance for a variety of criteria, including emissions, energy use, and monetary costs, and these can have spatial and temporal distributions. Because optimization of one parameter is likely to worsen another, identification of trade-offs is an important function of LCA.« less

Structural and functional social network attributes moderate the association of self-rated health with mental health in midlife and older adults.

PubMed

Windsor, Tim D; Rioseco, Pilar; Fiori, Katherine L; Curtis, Rachel G; Booth, Heather

2016-01-01

Social relationships are multifaceted, and different social network components can operate via different processes to influence well-being. This study examined associations of social network structure and relationship quality (positive and negative social exchanges) with mental health in midlife and older adults. The focus was on both direct associations of network structure and relationship quality with mental health, and whether these social network attributes moderated the association of self-rated health (SRH) with mental health. Analyses were based on survey data provided by 2001 (Mean age = 65, SD = 8.07) midlife and older adults. We used Latent Class Analysis (LCA) to classify participants into network types based on network structure (partner status, network size, contact frequency, and activity engagement), and used continuous measures of positive and negative social exchanges to operationalize relationship quality. Regression analysis was used to test moderation. LCA revealed network types generally consistent with those reported in previous studies. Participants in more diverse networks reported better mental health than those categorized into a restricted network type after adjustment for age, sex, education, and employment status. Analysis of moderation indicated that those with poorer SRH were less likely to report poorer mental health if they were classified into more diverse networks. A similar moderation effect was also evident for positive exchanges. The findings suggest that both quantity and quality of social relationships can play a role in buffering against the negative implications of physical health decline for mental health.

Who Should Be Targeted for the Prevention of Birth Defects? A Latent Class Analysis Based on a Large, Population-Based, Cross-Sectional Study in Shaanxi Province, Western China.

PubMed

Zhu, Zhonghai; Cheng, Yue; Yang, Wenfang; Li, Danyang; Yang, Xue; Liu, Danli; Zhang, Min; Yan, Hong; Zeng, Lingxia

2016-01-01

The wide range and complex combinations of factors that cause birth defects impede the development of primary prevention strategies targeted at high-risk subpopulations. Latent class analysis (LCA) was conducted to identify mutually exclusive profiles of factors associated with birth defects among women between 15 and 49 years of age using data from a large, population-based, cross-sectional study conducted in Shaanxi Province, western China, between August and October, 2013. The odds ratios (ORs) and 95% confidence intervals (CIs) of associated factors and the latent profiles of indicators of birth defects and congenital heart defects were computed using a logistic regression model. Five discrete subpopulations of participants were identified as follows: No folic acid supplementation in the periconceptional period (reference class, 21.37%); low maternal education level + unhealthy lifestyle (class 2, 39.75%); low maternal education level + unhealthy lifestyle + disease (class 3, 23.71%); unhealthy maternal lifestyle + advanced age (class 4, 4.71%); and multi-risk factor exposure (class 5, 10.45%). Compared with the reference subgroup, the other subgroups consistently had a significantly increased risk of birth defects (ORs and 95% CIs: class 2, 1.75 and 1.21-2.54; class 3, 3.13 and 2.17-4.52; class 4, 5.02 and 3.20-7.88; and class 5, 12.25 and 8.61-17.42, respectively). For congenital heart defects, the ORs and 95% CIs were all higher, and the magnitude of OR differences ranged from 1.59 to 16.15. A comprehensive intervention strategy targeting maternal exposure to multiple risk factors is expected to show the strongest results in preventing birth defects.

An efficient, large-scale, non-lattice-detection algorithm for exhaustive structural auditing of biomedical ontologies.

PubMed

Zhang, Guo-Qiang; Xing, Guangming; Cui, Licong

2018-04-01

One of the basic challenges in developing structural methods for systematic audition on the quality of biomedical ontologies is the computational cost usually involved in exhaustive sub-graph analysis. We introduce ANT-LCA, a new algorithm for computing all non-trivial lowest common ancestors (LCA) of each pair of concepts in the hierarchical order induced by an ontology. The computation of LCA is a fundamental step for non-lattice approach for ontology quality assurance. Distinct from existing approaches, ANT-LCA only computes LCAs for non-trivial pairs, those having at least one common ancestor. To skip all trivial pairs that may be of no practical interest, ANT-LCA employs a simple but innovative algorithmic strategy combining topological order and dynamic programming to keep track of non-trivial pairs. We provide correctness proofs and demonstrate a substantial reduction in computational time for two largest biomedical ontologies: SNOMED CT and Gene Ontology (GO). ANT-LCA achieved an average computation time of 30 and 3 sec per version for SNOMED CT and GO, respectively, about 2 orders of magnitude faster than the best known approaches. Our algorithm overcomes a fundamental computational barrier in sub-graph based structural analysis of large ontological systems. It enables the implementation of a new breed of structural auditing methods that not only identifies potential problematic areas, but also automatically suggests changes to fix the issues. Such structural auditing methods can lead to more effective tools supporting ontology quality assurance work. Copyright © 2018 Elsevier Inc. All rights reserved.

Opioid withdrawal, craving, and use during and after outpatient buprenorphine stabilization and taper: A discrete survival and growth mixture model

PubMed Central

Stotts, Angela L.; Green, Charles; Potter, Jennifer S.; Marino, Elise N.; Walker, Robrina; Weiss, Roger D.; Trivedi, Madhukar

2014-01-01

Most patients relapse to opioids within one month of opioid agonist detoxification, making the antecedents and parallel processes of first use critical for investigation. Craving and withdrawal are often studied in relationship to opioid outcomes, and a novel analytic strategy applied to these two phenomena may indicate targeted intervention strategies. Specifically, this secondary data analysis of the Prescription Opioid Addiction Treatment Study used a discrete-time mixture analysis with time-to-first opioid use (survival) simultaneously predicted by craving and withdrawal growth trajectories. This analysis characterized heterogeneity among prescription opioid-dependent individuals (N=653) into latent classes (i.e., latent class analysis [LCA]) during and after buprenorphine/naloxone stabilization and taper. A 4-latent class solution was selected for overall model fit and clinical parsimony. In order of shortest to longest time-to-first use, the 4 classes were characterized as 1) high craving and withdrawal 2) intermediate craving and withdrawal 3) high initial craving with low craving and withdrawal trajectories and 4) a low initial craving with low craving and withdrawal trajectories. Odds ratio calculations showed statistically significant differences in time-to-first use across classes. Generally, participants with lower baseline levels and greater decreases in craving and withdrawal during stabilization combined with slower craving and withdrawal rebound during buprenorphine taper remained opioid-free longer. This exploratory work expanded on the importance of monitoring craving and withdrawal during buprenorphine induction, stabilization, and taper. Future research may allow individually tailored and timely interventions to be developed to extend time-to-first opioid use. PMID:25282598

Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT).

PubMed

Lee, Adria D; Cassiday, Pamela K; Pawloski, Lucia C; Tatti, Kathleen M; Martin, Monte D; Briere, Elizabeth C; Tondella, M Lucia; Martin, Stacey W

2018-01-01

The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for ≤ 2 weeks were asked to return in 2-4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods-pertussis culture as the "gold standard," composite reference standard analysis (CRS), and latent class analysis (LCA). Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis.

Identifying and predicting subgroups of information needs among cancer patients: an initial study using latent class analysis.

PubMed

Neumann, Melanie; Wirtz, Markus; Ernstmann, Nicole; Ommen, Oliver; Längler, Alfred; Edelhäuser, Friedrich; Scheffer, Christian; Tauschel, Diethard; Pfaff, Holger

2011-08-01

Understanding how the information needs of cancer patients (CaPts) vary is important because met information needs affect health outcomes and CaPts' satisfaction. The goals of the study were to identify subgroups of CaPts based on self-reported cancer- and treatment-related information needs and to determine whether subgroups could be predicted on the basis of selected sociodemographic, clinical and clinician-patient relationship variables. Three hundred twenty-three CaPts participated in a survey using the "Cancer Patients Information Needs" scale, which is a new tool for measuring cancer-related information needs. The number of information need subgroups and need profiles within each subgroup was identified using latent class analysis (LCA). Multinomial logistic regression was applied to predict class membership. LCA identified a model of five subgroups exhibiting differences in type and extent of CaPts' unmet information needs: a subgroup with "no unmet needs" (31.4% of the sample), two subgroups with "high level of psychosocial unmet information needs" (27.0% and 12.0%), a subgroup with "high level of purely medical unmet information needs" (16.0%) and a subgroup with "high level of medical and psychosocial unmet information needs" (13.6%). An assessment of sociodemographic and clinical characteristics revealed that younger CaPts and CaPts' requiring psychological support seem to belong to subgroups with a higher level of unmet information needs. However, the most significant predictor for the subgroups with unmet information needs is a good clinician-patient relationship, i.e. subjective perception of high level of trust in and caring attention from nurses together with high degree of physician empathy seems to be predictive for inclusion in the subgroup with no unmet information needs. The results of our study can be used by oncology nurses and physicians to increase their awareness of the complexity and heterogeneity of information needs among CaPts and of clinically significant subgroups of CaPts. Moreover, regression analyses indicate the following association: Nurses and physicians seem to be able to reduce CaPts' unmet information needs by establishing a relationship with the patient, which is trusting, caring and empathic.

The creation, management, and use of data quality information for life cycle assessment.

PubMed

Edelen, Ashley; Ingwersen, Wesley W

2018-04-01

Despite growing access to data, questions of "best fit" data and the appropriate use of results in supporting decision making still plague the life cycle assessment (LCA) community. This discussion paper addresses revisions to assessing data quality captured in a new US Environmental Protection Agency guidance document as well as additional recommendations on data quality creation, management, and use in LCA databases and studies. Existing data quality systems and approaches in LCA were reviewed and tested. The evaluations resulted in a revision to a commonly used pedigree matrix, for which flow and process level data quality indicators are described, more clarity for scoring criteria, and further guidance on interpretation are given. Increased training for practitioners on data quality application and its limits are recommended. A multi-faceted approach to data quality assessment utilizing the pedigree method alongside uncertainty analysis in result interpretation is recommended. A method of data quality score aggregation is proposed and recommendations for usage of data quality scores in existing data are made to enable improved use of data quality scores in LCA results interpretation. Roles for data generators, data repositories, and data users are described in LCA data quality management. Guidance is provided on using data with data quality scores from other systems alongside data with scores from the new system. The new pedigree matrix and recommended data quality aggregation procedure can now be implemented in openLCA software. Additional ways in which data quality assessment might be improved and expanded are described. Interoperability efforts in LCA data should focus on descriptors to enable user scoring of data quality rather than translation of existing scores. Developing and using data quality indicators for additional dimensions of LCA data, and automation of data quality scoring through metadata extraction and comparison to goal and scope are needed.

Mutation analysis of Leber congenital amaurosis‑associated genes in patients with retinitis pigmentosa.

PubMed

Shen, Tao; Guan, Liping; Li, Shiqiang; Zhang, Jianguo; Xiao, Xueshan; Jiang, Hui; Yang, Jianhua; Guo, Xiangming; Wang, Jun; Zhang, Qingjiong

2015-03-01

The genetic defects underlying approximately half of all retinitis pigmentosa (RP) cases are unknown. A number of genes responsible for Leber congenital amaurosis (LCA) may also cause RP when they are mutated. Our previous study revealed that variants in the most frequently mutated nine exons accounted for approximately half of the mutations detected in a cohort of patients with LCA. The aim of the present study was to detect mutations in LCA-associated genes in patients with RP using two different strategies. Sanger sequencing was used to screen mutations in the nine exons in 293 patients with RP and exome sequencing was used to detect variants in 12 LCA-associated genes in 157 of the 293 patients with RP and then to validate the variants by Sanger sequencing. Potential pathogenic mutations were identified in four patients with early onset RP, including homozygous CRB1 mutations in two patients, compound heterozygous CRB1 mutations in one patient and compound heterozygous CEP290 mutations in one patient. The present study indicated that mutations in CEP290 may also be associated with RP but not with LCA. With the exception of CEP290, the remaining 11 genes known to be associated with LCA but not with RP are unlikely to be a common cause of RP.

Extended depth of focus intraocular lens: Chromatic performance

PubMed Central

Millán, Maria S.; Vega, Fidel

2017-01-01

We describe a first-and-second-diffractive-order intraocular lens ((1st,2nd)DIOL) within the class of hybrid refractive-diffractive designs for intraocular lenses (IOLs) and analyse its properties of focus extension and compensation of longitudinal chromatic aberration (LCA), particularly for lenses with low addition. Power, energy efficiency and their wavelength dependence are extended from monofocal IOL and conventional bifocal zeroth-and-first-diffractive-order IOL ((0th,1st)DIOL) to (1st,2nd)DIOL of low addition. Compensation of LCA is experimentally assessed in optical bench through the through-focus energy efficiency of three Tecnis IOLs with red, green and blue illuminations: ZA9003 (monofocal), ZKB00 (bifocal (0th,1st)DIOL with + 2.75 D add) and Symfony ZXR00. We prove Tecnis Symfony ZXR00 IOL can be considered an example of (1st,2nd)DIOL design of low addition, with LCA compensation in both the distance and intermediate foci, whereas the bifocal (0th,1st)DIOL does not compensate in the distance focus. However, the energy efficiency of (1st,2nd)DIOL for wavelengths other than the design wavelength is markedly more asymmetric. PMID:28966865

An LCA researcher's wish list--data and emission models needed to improve LCA studies of animal production.

PubMed

Cederberg, C; Henriksson, M; Berglund, M

2013-06-01

The last decade has seen an increase in environmental systems analysis of livestock production, resulting in a significant number of studies with a holistic approach often based on life-cycle assessment (LCA) methodology. The growing public interest in global warming has added to this development; guidelines for carbon footprint (CF) accounting have been developed, including for greenhouse gas (GHG) accounting of animal products. Here we give an overview of methods for estimating GHG emissions, with emphasis on nitrous oxide, methane and carbon from land use change, presently used in LCA/CF studies of animal products. We discuss where methods and data availability for GHGs and nitrogen (N) compounds most urgently need to be improved in order to produce more accurate environmental assessments of livestock production. We conclude that the top priority is to improve models for N fluxes and emissions from soils and to implement soil carbon change models in LCA/CF studies of animal products. We also point at the need for more farm data and studies measuring emissions from soils, manure and livestock in developing countries.

School and Peer Influences on the Academic Outcomes of African American Adolescents

PubMed Central

Estrada-Martinez, Lorena; Colin, Rosa J.; Jones, Brittni D.

2015-01-01

Little scholarship explores how adolescents’ beliefs about school and peers influence the academic outcomes of African American boys and girls. The sample included 612 African American boys (N=307, Mage=16.84) and girls (N=305, Mage=16.79). Latent class analysis (LCA) revealed unique patterns for African American boys and girls. Findings indicate that for African American boys, school attachment was protective, despite having peers who endorsed negative achievement values. Furthermore, socio-economic (SES) status was associated with higher grade point averages (GPA) for African American girls. Overall, these findings underscore the unique role of school, peer, and gendered experiences in lives of African American adolescents. PMID:26277404

Exploring the latent trait of Opioid Use Disorder criteria among frequent nonmedical prescription opioid users

PubMed Central

Castaldelli-Maia, João Mauricio; Andrade, Laura H.; Keyes, Katherine M.; Cerdá, Magdalena; Pilowsky, Daniel J.; Martins, Silvia S.

2016-01-01

Background There is a need to explore the dimensional and categorical phenotypes of criteria of opioid use disorder among frequent nonmedical users of prescription opioids (NMUPO) users. Methods We used pooled data of 2011–2012 National Survey on Drug Use and Health to examine reliability and phenotypic variability in the diagnosis of OUD secondary to NMUPO in a nationally-representative sample of 18+ years-old frequent past-year NMUPO users (120+ days, n=806). Through exploratory factor analysis (EFA) and latent class analysis (LCA), we examined 10 past-year OUD criteria. We examined associations between the latent classes and sociodemographic/psychiatric/NMUPO correlates. Results OUD criteria were unidimensional, and a three-class model was the overall best fitting solution for characterizing individuals into phenotypes along this unidimensional continuum: a “non-symptomatic class” (40.7%), “Tolerance-Time spent class” (29.0%) with high probability of endorsing Tolerance/Time Spent criteria, and a “High-moderate symptomatic class” (30.1%). The last class was significantly associated with being male, having insurance and obtaining prescription opioids (PO) nonmedically via “doctor shopping” as compared to the non-symptomatic class. “Tolerance-Time spent class” was significantly associated with being younger (18–25 years) and obtaining PO nonmedically from family/friends as compared to the non-symptomatic class. Conclusion This study revealed the different characteristics and routes of access to PO of different classes of frequent NMUPO users. It is possible that these groups may respond to different interventions, however such conclusions would require a clinical study. PMID:27302873

LCA Study for Pilot Scale Production of Cellulose Nano Crystals (CNC) from Wood Pulp

Treesearch

Hongmei Gu; Richard Reiner; Richard Bergman; Alan Rudie

2015-01-01

Interest in cellulose nanocrystals (CNC)/cellulose nanofibrils (CNF) made from woody biomass has been growing rapidly with close attention from pulp and paper industry, governments, universities, and research institutes. Many new products development with CNCs have been studied intensively. However, little life-cycle analysis (LCA) has been conducted for the...

Use of Systematic Methods to Improve Disease Identification in Administrative Data: The Case of Severe Sepsis.

PubMed

Shahraz, Saeid; Lagu, Tara; Ritter, Grant A; Liu, Xiadong; Tompkins, Christopher

2017-03-01

Selection of International Classification of Diseases (ICD)-based coded information for complex conditions such as severe sepsis is a subjective process and the results are sensitive to the codes selected. We use an innovative data exploration method to guide ICD-based case selection for severe sepsis. Using the Nationwide Inpatient Sample, we applied Latent Class Analysis (LCA) to determine if medical coders follow any uniform and sensible coding for observations with severe sepsis. We examined whether ICD-9 codes specific to sepsis (038.xx for septicemia, a subset of 995.9 codes representing Systemic Inflammatory Response syndrome, and 785.52 for septic shock) could all be members of the same latent class. Hospitalizations coded with sepsis-specific codes could be assigned to a latent class of their own. This class constituted 22.8% of all potential sepsis observations. The probability of an observation with any sepsis-specific codes being assigned to the residual class was near 0. The chance of an observation in the residual class having a sepsis-specific code as the principal diagnosis was close to 0. Validity of sepsis class assignment is supported by empirical results, which indicated that in-hospital deaths in the sepsis-specific class were around 4 times as likely as that in the residual class. The conventional methods of defining severe sepsis cases in observational data substantially misclassify sepsis cases. We suggest a methodology that helps reliable selection of ICD codes for conditions that require complex coding.

Exposure to Different Types of Violence and Subsequent Sexual Risk Behavior among Female STD Clinic Patients: A Latent Class Analysis

PubMed Central

Walsh, Jennifer L.; Senn, Theresa E.; Carey, Michael P.

2013-01-01

Objective Diverse forms of violence, including childhood maltreatment (CM), intimate partner violence (IPV), and exposure to community violence (ECV), have been linked separately with sexual risk behaviors. However, few studies have explored multiple experiences of violence simultaneously in relation to sexual risk-taking, especially in women who are most vulnerable to violent experiences. Methods Participants were 481 women (66% African American, Mage = 27 years) attending a publicly-funded STD clinic who reported on their past and current experiences with violence and their current sexual risk behavior. We identified patterns of experience with violence using latent class analysis (LCA) and investigated which combinations of experiences were associated with the riskiest sexual outcomes. Results Four classes of women with different experiences of violence were identified: Low Violence (39%), Predominantly ECV (20%), Predominantly CM (23%), and Multiply Victimized (18%). Women in the Multiply Victimized and Predominantly ECV classes reported the highest levels of sexual risk behavior, including more lifetime sexual partners and a greater likelihood of receiving STD treatment and using substances before sex. Conclusions Women with different patterns of violent experiences differed in their sexual risk behavior. Interventions to reduce sexual risk should address violence against women, focusing on experiences with multiple types of violence and experiences specifically with ECV. Additional research is needed to determine the best ways to address violence in sexual risk reduction interventions. PMID:23626921

Latent Class Analysis of Antisocial Behavior: Interaction of Serotonin Transporter Genotype and Maltreatment

PubMed Central

Li, James J.

2010-01-01

To improve understanding about genetic and environmental influences on antisocial behavior (ASB), we tested the association of the 44-base pair polymorphism of the serotonin transporter gene (5-HTTLPR) and maltreatment using latent class analysis in 2,488 boys and girls from Wave 1 of the National Longitudinal Study of Adolescent Health. In boys, ASB was defined by three classes (Exclusive Covert, Mixed Covert and Overt, and No Problems) whereas in girls, ASB was defined by two classes (Exclusive Covert, No Problems). In boys, 5-HTTLPR and maltreatment were not significantly related to ASB. However, in girls, maltreatment, but not 5-HTTLPR, was significantly associated with ASB. A significant interaction between 5-HTTLPR and maltreatment was also observed, where maltreated girls homozygous for the short allele were 12 times more likely to be classified in the Exclusive Covert group than in the No Problems group. Structural differences in the latent structure of ASB at Wave 2 and Wave 3 prevented repeat LCA modeling. However, using counts of ASB, 5-HTTLPR, maltreatment, and its interaction were unrelated to overt and covert ASB at Wave 2 and only maltreatment was related to covert ASB at Wave 3. We discuss these findings within the context of sex differences in ASB and relevant models of gene-environment interplay across developmental periods. PMID:20405199

Patterns of Exposure to Multiple Metals and Associations with Neurodevelopment of Preschool Children from Montevideo, Uruguay

PubMed Central

Kordas, Katarzyna; Ardoino, Graciela; Coffman, Donna L.; Queirolo, Elena I.; Ciccariello, Daniela; Mañay, Nelly; Ettinger, Adrienne S.

2015-01-01

While it is known that toxic metals contribute individually to child cognitive and behavioral deficits, we still know little about the effects of exposure to multiple metals, particularly when exposures are low. We studied the association between children's blood lead and hair arsenic, cadmium, and manganese and their performance on the Bayley Scales of Infant Development III. Ninety-two preschool children (age 13–42 months) from Montevideo, Uruguay, provided a hair sample and 78 had a blood lead level (BLL) measurement. Using latent class analysis (LCA), we identified four groups of exposure based on metal concentrations: (1) low metals, (2) low-to-moderate metals, (3) high lead and cadmium, and (4) high metals. Using the four-group exposure variable as the main predictor, and fitting raw scores on the cognitive, receptive vocabulary, and expressive vocabulary scales as dependent variables, both complete-case and multiple imputation (MI) analyses were conducted. We found no association between multiple-metal exposures and neurodevelopment in covariate-adjusted models. This study demonstrates the use of LCA together with MI to determine patterns of exposure to multiple toxic metals and relate these to child neurodevelopment. However, because the overall study population was small, other studies with larger sample sizes are needed to investigate these associations. PMID:25694786

Patterns of productive activity engagement as a longitudinal predictor of depressive symptoms among older adults in urban China.

PubMed

Liu, Huiying; Lou, Vivian W Q

2017-11-01

Using two waves of panel data from the China Health and Retirement Longitudinal Study, this study prospectively assessed whether four distinct patterns of productive activity engagement would predict depressive symptoms among older adults in urban China two years later. A sample of urban residents aged 60 or above at Wave 1 and who were interviewed in both waves (N = 2398) was used. Latent class analysis (LCA) was conducted to identify distinct patterns of productive activity engagement that occurred within the Wave 1 data. Next, the generalized estimating equations were used to assess whether identified patterns predicted the levels of depressive symptoms measured at Wave 2. Our use of LCA confirmed the existence of four distinct patterns of productive activity engagement among the study sample: Informal Helper/Carer, Working-Caring Engager, Civic Contributor, and Low/Spousal Carer. All of these three patterns exhibited significantly lower levels of depressive symptoms than that of Low/Spousal Carer two years later. Our use of individual-based categorization of productive engagement better captured the reality of older adults performing various productive activities than summative scales of productive activities did and, therefore, provided a more valid clarification of differential well-being outcomes among older adults.

Health behavior-related indicator of lifestyle: application in the ELSA-Brasil study.

PubMed

Patrão, Ana Luísa; Almeida, Maria-da-Conceição C; Alvim, Sheila; Chor, Dora; Aquino, Estela M L

2018-05-01

Various behaviors are considered health enhancing. Nevertheless, according to the current scientific literature, four health behaviors are considered particularly risky in view of their association with a group of chronic diseases: 1) smoking; 2) excessive alcohol consumption; 3) poor diet; and 4) lack of physical activity. Theoretically, it should be possible to make improvements to one's health by maximizing the number of healthy behaviors and minimizing the unhealthy ones. However, in reality, the different behaviors interconnect to create more complex lifestyles. Therefore, the objective of this paper is to present the construction of a lifestyle indicator based on health behaviors selected in the ELSA-Brazil study. This indicator revealed two lifestyles: less healthy and healthier lifestyles. The model proved adequate and was confirmed using latent class analysis (LCA). Agreement was 83.2 between the indicator and the LCA results, with a kappa coefficient of 0.65. Women were more likely to have a healthier lifestyle than men, reinforcing the scientific consistency of the indicator, since this finding is in agreement with data from the scientific literature. The indicator created to define lifestyle was found to have scientific consistency and validity; therefore, its use can be recommended for future population-based studies concerning the promotion of health and healthy lifestyles.

Poly-victimization from different methodological approaches using the juvenile victimization questionnaire: Are we identifying the same victims?

PubMed

Segura, Anna; Pereda, Noemí; Guilera, Georgina

2018-01-01

This study aims to determine whether three different methodological approaches used to assess poly-victimization that apply the Juvenile Victimization Questionnaire (JVQ; Finkelhor, Hamby, Ormrod, & Turner, 2005) identify the same group of adolescent poly-victims. The sample consisted of 1,105 adolescents (590 males and 515 females), aged 12-17 years old (M = 14.52, SD = 1.76) and recruited from seven secondary schools in Spain. The JVQ was used to assess lifetime and past-year experiences of victimization. Poly-victims were more likely to experience all types of victimization than victims, regardless of the method used. The degree of agreement between the methods for identifying poly-victimization was moderate for both timeframes, with the highest agreements being recorded between the one-above-the-mean number of victimizations and Latent Class Analysis (LCA) for lifetime, and between the top 10% and LCA for past-year victimization. Researchers and clinicians should be aware that the use of different methods to define poly-victimization may mean that different victims are identified. The choice of one method or another may have important implications. In consequence, focusing on how we operationalize poly-victimization should be a priority in the near future.

Opioid withdrawal, craving, and use during and after outpatient buprenorphine stabilization and taper: a discrete survival and growth mixture model.

PubMed

Northrup, Thomas F; Stotts, Angela L; Green, Charles; Potter, Jennifer S; Marino, Elise N; Walker, Robrina; Weiss, Roger D; Trivedi, Madhukar

2015-02-01

Most patients relapse to opioids within one month of opioid agonist detoxification, making the antecedents and parallel processes of first use critical for investigation. Craving and withdrawal are often studied in relationship to opioid outcomes, and a novel analytic strategy applied to these two phenomena may indicate targeted intervention strategies. Specifically, this secondary data analysis of the Prescription Opioid Addiction Treatment Study used a discrete-time mixture analysis with time-to-first opioid use (survival) simultaneously predicted by craving and withdrawal growth trajectories. This analysis characterized heterogeneity among prescription opioid-dependent individuals (N=653) into latent classes (i.e., latent class analysis [LCA]) during and after buprenorphine/naloxone stabilization and taper. A 4-latent class solution was selected for overall model fit and clinical parsimony. In order of shortest to longest time-to-first use, the 4 classes were characterized as 1) high craving and withdrawal, 2) intermediate craving and withdrawal, 3) high initial craving with low craving and withdrawal trajectories and 4) a low initial craving with low craving and withdrawal trajectories. Odds ratio calculations showed statistically significant differences in time-to-first use across classes. Generally, participants with lower baseline levels and greater decreases in craving and withdrawal during stabilization combined with slower craving and withdrawal rebound during buprenorphine taper remained opioid-free longer. This exploratory work expanded on the importance of monitoring craving and withdrawal during buprenorphine induction, stabilization, and taper. Future research may allow individually tailored and timely interventions to be developed to extend time-to-first opioid use. Copyright © 2014 Elsevier Ltd. All rights reserved.

Convergence Speed of a Dynamical System for Sparse Recovery

NASA Astrophysics Data System (ADS)

Balavoine, Aurele; Rozell, Christopher J.; Romberg, Justin

2013-09-01

This paper studies the convergence rate of a continuous-time dynamical system for L1-minimization, known as the Locally Competitive Algorithm (LCA). Solving L1-minimization} problems efficiently and rapidly is of great interest to the signal processing community, as these programs have been shown to recover sparse solutions to underdetermined systems of linear equations and come with strong performance guarantees. The LCA under study differs from the typical L1 solver in that it operates in continuous time: instead of being specified by discrete iterations, it evolves according to a system of nonlinear ordinary differential equations. The LCA is constructed from simple components, giving it the potential to be implemented as a large-scale analog circuit. The goal of this paper is to give guarantees on the convergence time of the LCA system. To do so, we analyze how the LCA evolves as it is recovering a sparse signal from underdetermined measurements. We show that under appropriate conditions on the measurement matrix and the problem parameters, the path the LCA follows can be described as a sequence of linear differential equations, each with a small number of active variables. This allows us to relate the convergence time of the system to the restricted isometry constant of the matrix. Interesting parallels to sparse-recovery digital solvers emerge from this study. Our analysis covers both the noisy and noiseless settings and is supported by simulation results.

Comprehensive molecular diagnosis of 179 Leber congenital amaurosis and juvenile retinitis pigmentosa patients by targeted next generation sequencing

PubMed Central

Wang, Xia; Wang, Hui; Sun, Vincent; Tuan, Han-Fang; Keser, Vafa; Wang, Keqing; Ren, Huanan; Lopez, Irma; Zaneveld, Jacques E; Siddiqui, Sorath; Bowles, Stephanie; Khan, Ayesha; Salvo, Jason; Jacobson, Samuel G; Iannaccone, Alessandro; Wang, Feng; Birch, David; Heckenlively, John R; Fishman, Gerald A; Traboulsi, Elias I; Li, Yumei; Wheaton, Dianna; Koenekoop, Robert K; Chen, Rui

2014-01-01

Background Leber congenital amaurosis (LCA) and juvenile retinitis pigmentosa (RP) are inherited retinal diseases that cause early onset severe visual impairment. An accurate molecular diagnosis can refine the clinical diagnosis and allow gene specific treatments. Methods We developed a capture panel that enriches the exonic DNA of 163 known retinal disease genes. Using this panel, we performed targeted next generation sequencing (NGS) for a large cohort of 179 unrelated and prescreened patients with the clinical diagnosis of LCA or juvenile RP. Systematic NGS data analysis, Sanger sequencing validation, and segregation analysis were utilised to identify the pathogenic mutations. Patients were revisited to examine the potential phenotypic ambiguity at the time of initial diagnosis. Results Pathogenic mutations for 72 patients (40%) were identified, including 45 novel mutations. Of these 72 patients, 58 carried mutations in known LCA or juvenile RP genes and exhibited corresponding phenotypes, while 14 carried mutations in retinal disease genes that were not consistent with their initial clinical diagnosis. We revisited patients in the latter case and found that homozygous mutations in PRPH2 can cause LCA/juvenile RP. Guided by the molecular diagnosis, we reclassified the clinical diagnosis in two patients. Conclusions We have identified a novel gene and a large number of novel mutations that are associated with LCA/juvenile RP. Our results highlight the importance of molecular diagnosis as an integral part of clinical diagnosis. PMID:23847139

The 2d-LCA as an alternative to x-wires

NASA Astrophysics Data System (ADS)

Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

2015-11-01

The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

2d-LCA - an alternative to x-wires

NASA Astrophysics Data System (ADS)

Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

2014-11-01

The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150 kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

Resource recovery from residual household waste: An application of exergy flow analysis and exergetic life cycle assessment.

PubMed

Laner, David; Rechberger, Helmut; De Soete, Wouter; De Meester, Steven; Astrup, Thomas F

2015-12-01

Exergy is based on the Second Law of thermodynamics and can be used to express physical and chemical potential and provides a unified measure for resource accounting. In this study, exergy analysis was applied to four residual household waste management scenarios with focus on the achieved resource recovery efficiencies. The calculated exergy efficiencies were used to compare the scenarios and to evaluate the applicability of exergy-based measures for expressing resource quality and for optimizing resource recovery. Exergy efficiencies were determined based on two approaches: (i) exergy flow analysis of the waste treatment system under investigation and (ii) exergetic life cycle assessment (LCA) using the Cumulative Exergy Extraction from the Natural Environment (CEENE) as a method for resource accounting. Scenario efficiencies of around 17-27% were found based on the exergy flow analysis (higher efficiencies were associated with high levels of material recycling), while the scenario efficiencies based on the exergetic LCA lay in a narrow range around 14%. Metal recovery was beneficial in both types of analyses, but had more influence on the overall efficiency in the exergetic LCA approach, as avoided burdens associated with primary metal production were much more important than the exergy content of the recovered metals. On the other hand, plastic recovery was highly beneficial in the exergy flow analysis, but rather insignificant in exergetic LCA. The two approaches thereby offered different quantitative results as well as conclusions regarding material recovery. With respect to resource quality, the main challenge for the exergy flow analysis is the use of exergy content and exergy losses as a proxy for resource quality and resource losses, as exergy content is not per se correlated with the functionality of a material. In addition, the definition of appropriate waste system boundaries is critical for the exergy efficiencies derived from the flow analysis, as it is constrained by limited information available about the composition of flows in the system as well as about secondary production processes and their interaction with primary or traditional production chains. In the exergetic LCA, resource quality could be reflected by the savings achieved by product substitution and the consideration of the waste's upstream burden allowed for an evaluation of the waste's resource potential. For a comprehensive assessment of resource efficiency in waste LCA, the sensitivity of accounting for product substitution should be carefully analyzed and cumulative exergy consumption measures should be complimented by other impact categories. Copyright © 2015 Elsevier Ltd. All rights reserved.

Life-Cycle Inventory Analysis of Laminated Veneer Lumber Production in the United States

Treesearch

Richard D. Bergman

2015-01-01

Documenting the environmental performance of building products is becoming increasingly common. Developing environmental product declarations (EPDs) based on life-cycle assessment (LCA) data is one way to provide scientific documentation. Many U.S. structural wood products have LCA-based “eco-labels” using the ISO standard. However, the standard requires underlying...

Life-Cycle Inventory Analysis of I-joist Production in the United States

Treesearch

Richard D. Bergman

2015-01-01

Documenting the environmental performance of building products is becoming increasingly common. Creating environmental product declarations (EPDs) based on life-cycle assessment (LCA) data is one approach to provide scientific documentation of the products’ environmental performance. Many U.S. structural wood products have LCA-based “eco-labels” developed under the ISO...

Behavioral change in response to a statewide tobacco tax increase and differences across socioeconomic status.

PubMed

Parks, Michael J; Kingsbury, John H; Boyle, Raymond G; Choi, Kelvin

2017-10-01

Tobacco use is a leading behavioral risk factor for morbidity and mortality, and the tobacco epidemic disproportionately affects low-socioeconomic status (SES) populations. Taxation is effective for reducing cigarette use, and it is an effective population-based policy for reducing SES-related tobacco disparities. However, progress in implementing cigarette excise taxes has stalled across the United States, and there is a dearth of research on the full spectrum of behavioral shifts that result from taxes, particularly among low-SES populations. This project documents the impact of Minnesota's $1.75 cigarette tax increase implemented in 2013. Data come from the 2014 Minnesota Adult Tobacco Survey. Descriptive analyses and Latent Class Analysis (LCA) were used to provide a typology of the tax impact. From the LCA, six classes were identified, and 42% of respondents were classified as reporting action-oriented behavioral change related to the tax-8% reported sustained smoking abstinence. We found differential behavior change across levels of SES. Low-SES and medium/high-SES individuals were equally likely to report complete tobacco cessation, but the prevalence of daily smokers who reported action-oriented behavior without sustained cessation was nearly double for low-SES individuals. Smokers report a range of behavioral changes in response to cigarette taxes, with differences across SES. The majority of smokers, and particularly low-SES smokers, report behavioral steps toward quitting or achieving sustained tobacco cessation in response to cigarette taxes. Complementary population-based programs geared toward assisting individuals, especially low-SES individuals, to achieve continuous tobacco cessation could increase the reach and effectiveness of cigarette taxes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Involvement of LCA5 in Leber congenital amaurosis and retinitis pigmentosa in the Spanish population.

PubMed

Corton, Marta; Avila-Fernandez, Almudena; Vallespín, Elena; López-Molina, María Isabel; Almoguera, Berta; Martín-Garrido, Esther; Tatu, Sorina D; Khan, M Imran; Blanco-Kelly, Fiona; Riveiro-Alvarez, Rosa; Brión, María; García-Sandoval, Blanca; Cremers, Frans P M; Carracedo, Angel; Ayuso, Carmen

2014-01-01

We aimed to identify novel genetic defects in the LCA5 gene underlying Leber congenital amaurosis (LCA) in the Spanish population and to describe the associated phenotype. Case series. A cohort of 217 unrelated Spanish families affected by autosomal recessive or isolated retinal dystrophy, that is, 79 families with LCA and 138 families with early-onset retinitis pigmentosa (EORP). A total of 100 healthy, unrelated Spanish individuals were screened as controls. High-resolution homozygosity mapping was performed in 44 patients with LCA using genome-wide single nucleotide polymorphism (SNP) microarrays. Direct sequencing of the LCA5 gene was performed in 5 patients who showed homozygous regions at chromosome 6 and in 173 unrelated individuals with LCA or EORP. The ophthalmic history of 8 patients carrying LCA5 mutations was reviewed and additional examinations were performed, including electroretinography (ERG), optical coherence tomography (OCT), and fundus photography. Single nucleotide polymorphism genotyping, identity-by-descent (IBD) regions, LCA5 mutations, best-corrected visual acuity, visual field assessments, fundus appearance, ERG, and OCT findings. Four novel and 2 previously reported LCA5 mutations have been identified in 6 unrelated families with LCA by homozygosity mapping or Sanger sequencing. Thus, LCA5 mutations have a frequency of 7.6% in the Spanish population. However, no LCA5 mutations were found in 138 patients with EORP. Although most of the identified LCA5 mutations led to a truncated protein, a likely pathogenic missense variant was identified for the first time as a cause of LCA, segregating in 2 families. We also have characterized a novel splicing site mutation at the RNA level, demonstrating that the mutant LCA5 transcript was absent in a patient. All patients carrying LCA5 mutations presented nystagmus, night blindness, and progressive loss of visual acuity and visual field leading to blindness toward the third decade of life. Fundoscopy showed fundus features of pigmentary retinopathy with atrophic macular lesions. This work reveals a higher frequency of LCA5 mutations in a Spanish LCA cohort than in other populations. This study established gene-specific frequencies and the underlying phenotype of LCA5 mutations in the Spanish population. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Social life cycle assessment and participatory approaches: A methodological proposal applied to citrus farming in Southern Italy.

PubMed

De Luca, Anna Irene; Iofrida, Nathalie; Strano, Alfio; Falcone, Giacomo; Gulisano, Giovanni

2015-07-01

Recently, Social Life Cycle Assessment (S-LCA) has been developed under the methodological framework of Life Cycle Thinking (LCT) to evaluate the social impacts that emerge during the overall life cycle of a product or service. There is not yet a standardized methodology for S-LCA as there is for environmental LCA (eLCA), due to the nature of social impacts that do not depend only on the processes themselves, but also on the behavior and context of actors (manufactures, consumers, local community members, etc.). One of the most critical steps in the application of S-LCA concerns the choice of criteria for selecting affected actors, impact categories, subcategories, and the taxonomic relation among them. Moreover, the importance (in terms of weight) of these impacts may be felt differently by affected actors, confirming the importance of the context within which impacts arise. In this sense, the integration of participatory tools can be useful in making the S-LCA more locally relevant. The aim of the present study is twofold. First, we will outline a methodology that combines S-LCA with two research tools. The first is the focus group, adopted from qualitative research. The second is the Analytic Hierarchy Process (AHP), adopted from operational research, which belongs to the framework of Multicriteria Decision Analysis (MCDA). These have been used to make the S-LCA more locally relevant and to legitimate the criteria used. Second, we will test this methodology by applying it to a specific field, i.e., 3 production areas and 3 different crop systems of citrus growing in the Calabria region in Southern Italy. Citrus growing is one of the most important agricultural sectors at regional level, and it is also well known for issues of social concern, particularly in relation to immigrant workers. The results show a number of differences between cases and could offer useful insights to both local decision makers, such as agricultural entrepreneurs, and to those public decision makers that design and implement territorial planning strategies. Results have allowed the authors to rank the social performance of each case and to reflect on the most critical steps in conducting an S-LCA. The integration of qualitative techniques and a multicriteria in sLCA allows catching local specificities by involving local experts and stakeholders Results highlighted that impact categories mostly contributed to performance differences Public deciders can be supported in deciding which farming practices should be encouraged, which social domains must be paid more attention, and where social problems mostly occur The methodological application allowed the authors also to foresee the feasibility of the integration of LCA and LCC results as inputs in sLCA to conduct a Life Cycle Sustainability Assessment (LCSA). © 2015 SETAC.

A novel examination of exposure patterns and posttraumatic stress after a university mass murder.

PubMed

Liu, Sabrina R; Kia-Keating, Maryam

2018-03-05

Occurring at an alarming rate in the United States, mass violence has been linked to posttraumatic stress symptoms (PTSS) in both direct victims and community members who are indirectly exposed. Identifying what distinct exposure patterns exist and their relation to later PTSS has important clinical implications. The present study determined classes of exposure to an event of mass violence, and if PTSS differed across classes. First- and second-year college students (N = 1,189) participated in a confidential online survey following a mass murder at their university, which assessed event exposure and PTSS 3 months later. Latent class analysis (LCA) was used to empirically determine distinct classes of exposure patterns and links between class membership and PTSS. The final model yielded 4 classes: minimal exposure (55.5% of sample), auditory exposure (29.4% of sample), visual exposure (10% of sample), and interpersonal exposure (5% of sample). More severe direct exposure (i.e., the visual exposure class) was associated with significantly higher levels of PTSS than the auditory exposure or minimal exposure classes, as was the interpersonal exposure class. There were no significant differences in PTSS between the auditory exposure and minimal exposure classes or the visual exposure and interpersonal exposure classes. Results point to the differential impact of exposure categories, and provide empirical evidence for distinguishing among auditory, visual, and interpersonal exposures to events of mass violence on college campuses. Clinical implications suggest that visual and interpersonal exposure may warrant targeted efforts following mass violence. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Review of LCA studies of solid waste management systems – Part II: Methodological guidance for a better practice

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

Laurent, Alexis, E-mail: alau@dtu.dk; Clavreul, Julie; Bernstad, Anna

Highlights: • We perform a critical review of 222 LCA studies of solid waste management systems. • We analyse the past LCA practice against the ISO standard and ILCD Handbook guidance. • Malpractices exist in many methodological aspects with large variations among studies. • Many of these aspects are important for the reliability of the results. • We provide detailed recommendations to practitioners of waste management LCAs. - Abstract: Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of themore » provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs.« less

A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data: SPSS TwoStep Cluster analysis, Latent Gold and SNOB.

PubMed

Kent, Peter; Jensen, Rikke K; Kongsted, Alice

2014-10-02

There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold LCA and SNOB LCA). The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program's ease of use and interpretability of the presentation of results.We analysed five real datasets of varying complexity in a secondary analysis of data from other research projects. Three datasets contained only MRI findings (n = 2,060 to 20,810 vertebral disc levels), one dataset contained only pain intensity data collected for 52 weeks by text (SMS) messaging (n = 1,121 people), and the last dataset contained a range of clinical variables measured in low back pain patients (n = 543 people). Four artificial datasets (n = 1,000 each) containing subgroups of varying complexity were also analysed testing the ability of these clustering methods to detect subgroups and correctly classify individuals when subgroup membership was known. The results from the real clinical datasets indicated that the number of subgroups detected varied, the certainty of classifying individuals into those subgroups varied, the findings had perfect reproducibility, some programs were easier to use and the interpretability of the presentation of their findings also varied. The results from the artificial datasets indicated that all three clustering methods showed a near-perfect ability to detect known subgroups and correctly classify individuals into those subgroups. Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may suit other types of data and clinical research questions.

Emerging role of Geographical Information System (GIS), Life Cycle Assessment (LCA) and spatial LCA (GIS-LCA) in sustainable bioenergy planning.

PubMed

Hiloidhari, Moonmoon; Baruah, D C; Singh, Anoop; Kataki, Sampriti; Medhi, Kristina; Kumari, Shilpi; Ramachandra, T V; Jenkins, B M; Thakur, Indu Shekhar

2017-10-01

Sustainability of a bioenergy project depends on precise assessment of biomass resource, planning of cost-effective logistics and evaluation of possible environmental implications. In this context, this paper reviews the role and applications of geo-spatial tool such as Geographical Information System (GIS) for precise agro-residue resource assessment, biomass logistic and power plant design. Further, application of Life Cycle Assessment (LCA) in understanding the potential impact of agro-residue bioenergy generation on different ecosystem services has also been reviewed and limitations associated with LCA variability and uncertainty were discussed. Usefulness of integration of GIS into LCA (i.e. spatial LCA) to overcome the limitations of conventional LCA and to produce a holistic evaluation of the environmental benefits and concerns of bioenergy is also reviewed. Application of GIS, LCA and spatial LCA can help alleviate the challenges faced by ambitious bioenergy projects by addressing both economics and environmental goals. Copyright © 2017 Elsevier Ltd. All rights reserved.

A method for improving reliability and relevance of LCA reviews: the case of life-cycle greenhouse gas emissions of tap and bottled water.

PubMed

Fantin, Valentina; Scalbi, Simona; Ottaviano, Giuseppe; Masoni, Paolo

2014-04-01

The purpose of this study is to propose a method for harmonising Life Cycle Assessment (LCA) literature studies on the same product or on different products fulfilling the same function for a reliable and meaningful comparison of their life-cycle environmental impacts. The method is divided in six main steps which aim to rationalize and quicken the efforts needed to carry out the comparison. The steps include: 1) a clear definition of the goal and scope of the review; 2) critical review of the references; 3) identification of significant parameters that have to be harmonised; 4) harmonisation of the parameters; 5) statistical analysis to support the comparison; 6) results and discussion. This approach was then applied to the comparative analysis of the published LCA studies on tap and bottled water production, focussing on Global Warming Potential (GWP) results, with the aim to identify the environmental preferable alternative. A statistical analysis with Wilcoxon's test confirmed that the difference between harmonised GWP values of tap and bottled water was significant. The results obtained from the comparison of the harmonised mean GWP results showed that tap water always has the best environmental performance, even in case of high energy-consuming technologies for drinking water treatments. The strength of the method is that it enables both performing a deep analysis of the LCA literature and obtaining more consistent comparisons across the published LCAs. For these reasons, it can be a valuable tool which provides useful information for both practitioners and decision makers. Finally, its application to the case study allowed both to supply a description of systems variability and to evaluate the importance of several key parameters for tap and bottled water production. The comparative review of LCA studies, with the inclusion of a statistical decision test, can validate and strengthen the final statements of the comparison. Copyright © 2014 Elsevier B.V. All rights reserved.

Patterns of Drug Use, Risky Behavior, and Health Status Among Persons Who Inject Drugs Living in San Diego, California: A Latent Class Analysis

PubMed Central

Roth, Alexis M.; Armenta, Richard A.; Wagner, Karla D.; Roesch, Scott C.; Bluthenthal, Ricky N.; Cuevas-Mota, Jazmine; Garfein, Richard S.

2015-01-01

Background Among persons who inject drugs (PWID), polydrug use (the practice of mixing multiple drugs/alcohol sequentially or simultaneously) increases risk for HIV transmission and unintentional overdose deaths. Research has shown local drug markets influence drug use practices. However, little is known about the impact of drug mixing in markets dominated by black tar heroin and methamphetamine, such as the western United States. Methods Data were collected through an ongoing longitudinal study examining drug use, risk behavior, and health status among PWID. Latent class analysis (LCA) was used to identify patterns of substance use (heroin, methamphetamine, prescription drugs, alcohol, and marijuana) via multiple administration routes (injecting, smoking, and swallowing). Logistic regression was used to identify behaviors and health indicators associated with drug use class. Results The sample included 511 mostly white (51.5%) males (73.8%), with mean age of 43.5 years. Two distinct classes of drug users predominated: methamphetamine by multiple routes (51%) and heroin by injection (49%). In multivariable logistic regression, class membership was associated with age, race, and housing status. PWID who were HIV-seropositive and reported prior sexually transmitted infections had increased odds of belonging to the methamphetamine class. Those who were HCV positive and reported previous opioid overdose had an increased odds of being in the primarily heroin injection class (all P-values < .05). Conclusion Risk behaviors and health outcomes differed between PWID who primarily inject heroin vs. those who use methamphetamine. The findings suggest that in a region where PWID mainly use black tar heroin or methamphetamine, interventions tailored to sub-populations of PWID could improve effectiveness. PMID:25313832

The heterogeneous health latent classes of elderly people and their socio-demographic characteristics in Taiwan.

PubMed

Liu, Li-Fan; Tian, Wei-Hua; Yao, Hui-Ping

2014-01-01

The health care needs of elderly people were influenced by their heterogeneity. This study aimed to identify the health latent classes of elderly people by using latent class analysis to deal with heterogeneity and examine their socio-demographic characteristics. Data came from the 2005 National Health Interview Survey (NHIS) in Taiwan. In total, 2449 elderly individuals with available health indicators were examined in latent class analysis (LCA), and 2217 elderly community-dwellings with complete socio-demographic data were analyzed by multinomial logistic regression. Four health latent classes were identified which included 1066 (43.5%) people in the High Comorbidity (HC), 152 (6.2%) in the Functional Impairment (FI), 252 (10.3%) in the Frail (FR), and 979 (40.0%) in the Relatively Healthy (RH) group. Multinomial logistic regressions revealed socio-demographic characteristics among health classes. The variables associated with an increased likelihood of being in the FR group were age, female, and living with families. They were also correlated to ethnicity and educations. Apart from age and gender, the Functional Impairment group was less likely to be ethnicity of Hakka, more likely to live with others than were the RH group. The HC group tended to be younger, with higher educations, and more likely to live in urban area than the Functional Impairment group. The correlations between health classes and socio-demographic factors were discussed. The health status of elderly people includes a variety of health indicators. A person-centered approach is critical to identify the health heterogeneity of elderly people and manage their care needs by targeting differential aging. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Understanding the LCA and ISO water footprint: A response to ...

EPA Pesticide Factsheets

Water footprinting has emerged as an important approach to assess water use related effects from consumption of goods and services. Assessment methods are proposed by two different communities, the Water Footprint Network (WFN) and the Life Cycle Assessment (LCA) community. The proposed methods are broadly similar and encompass both the computation of water use and its impacts, but differ in communication of a water footprint result. In this paper, we explain the role and goal of LCA and ISO-compatible water footprinting and resolve the six issues raised by Hoekstra (2016) in “A critique on the water-scarcity weighted water footprint in LCA”. By clarifying the concerns, we identify both the overlapping goals in the WFN and LCA water footprint assessments and discrepancies between them. The main differing perspective between the WFN and LCA-based approach seems to relate to the fact that LCA aims to account for environmental impacts, while the WFN aims to account for water productivity of global fresh water as a limited resource. We conclude that there is potential to use synergies in research for the two approaches and highlight the need for proper declaration of the methods applied. This paper advances efforts to understand ways to accurately capture use of water in life cycle analysis in other contexts. As the paper indicates, there is a discussion about whether quantities of water should be weighted by some local stress factor. This paper attempts to brid

Review of LCA studies of solid waste management systems--part II: methodological guidance for a better practice.

PubMed

Laurent, Alexis; Clavreul, Julie; Bernstad, Anna; Bakas, Ioannis; Niero, Monia; Gentil, Emmanuel; Christensen, Thomas H; Hauschild, Michael Z

2014-03-01

Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs. Copyright © 2013 Elsevier Ltd. All rights reserved.

An eco-balance of a recycling plant for spent lead-acid batteries.

PubMed

Salomone, Roberta; Mondello, Fabio; Lanuzza, Francesco; Micali, Giuseppe

2005-02-01

This study applies Life Cycle Assessment (LCA) methodology to present an eco-balance of a recycling plant that treats spent lead-acid batteries. The recycling plant uses pyrometallurgical treatment to obtain lead from spent batteries. The application of LCA methodology (ISO 14040 series) enabled us to assess the potential environmental impacts arising from the recycling plant's operations. Thus, net emissions of greenhouse gases as well as other major environmental consequences were examined and hot spots inside the recycling plant were identified. A sensitivity analysis was also performed on certain variables to evaluate their effect on the LCA study. The LCA of a recycling plant for spent lead-acid batteries presented shows that this methodology allows all of the major environmental consequences associated with lead recycling using the pyrometallurgical process to be examined. The study highlights areas in which environmental improvements are easily achievable by a business, providing a basis for suggestions to minimize the environmental impact of its production phases, improving process and company performance in environmental terms.

Innovation strategies in a fruit growers association impacts assessment by using combined LCA and s-LCA methodologies.

PubMed

Tecco, Nadia; Baudino, Claudio; Girgenti, Vincenzo; Peano, Cristiana

2016-10-15

In the challenging world of territorial transformations within the agriculture, there is an increasing need for an integrated methodological framework of assessment that is able to reconcile the demand for solutions that are both economically sustainable and contribute to environmental and social improvement. This study aims to assess the introduction of innovation into agro-food systems by combining an environmental life cycle (LCA) assessment and a social life cycle assessment (s-LCA) to support the decision making process of a fruit growers co-op for the adoption of mulching and covering in raspberry farming. LCA and s-LCA have been applied independently under specific consistency requirements, selecting two scenarios to compare the impact with (1) and without (2) the innovation and then combined within a cause-effect chain. The interactions between the environment and socioeconomic components were considered within a nested frameset of business and territorial features. The total emissions from raspberry production in Scenario 1, according to the Global Warming Potential (GWP) Impact Category amounted to 2.2840kg of CO2 eq. In Scenario 2, the impact of production was associated with a GWP of 0.1682kg of CO2 eq. Social repercussions analysis from Scenario 1 compared to Scenario 2 indicate more satisfaction for working conditions and the management of climate risks. The mulching and covering, implemented within a given framework of farm activity, created conditions for the preservation of a model in which raspberry production contributes to landscape protection, the business sustainability of farms and the creation of employment. The combined use of the two methods contributes to the development of a strategy planning due to its ability to deliver, as well as specific analysis at a functional level, a wider framework for assessing the consistency of the impacts related to innovation in raspberry production. Copyright © 2016 Elsevier B.V. All rights reserved.

Patterns of Online and Offline Connectedness Among Gay, Bisexual, and Other Men Who Have Sex with Men.

PubMed

Card, Kiffer G; Armstrong, Heather L; Lachowsky, Nathan J; Cui, Zishan; Zhu, Julia; Roth, Eric A; Hogg, Robert S

2017-10-26

This study examined patterns of connectedness among 774 sexually-active gay, bisexual, and other men who have sex with men (GBM), aged ≥ 16 years, recruited using respondent-driven sampling in Metro Vancouver. Latent class analysis examined patterns of connectedness including: attendance at gay venues/events (i.e., bars/clubs, community groups, pride parades), social time spent with GBM, use of online social and sex seeking apps/websites, and consumption of gay media. Multinomial regression identified correlates of class membership. A three-class LCA solution was specified: Class 1 "Socialites" (38.8%) were highly connected across all indicators. Class 2 "Traditionalists" (25.7%) were moderately connected, with little app/website-use. Class 3 "Techies" (35.4%) had high online connectedness and relatively lower in-person connectedness. In multivariable modelling, Socialites had higher collectivism than Traditionalists, who had higher collectivism than Techies. Socialites also had higher annual incomes than other classes. Techies were more likely than Traditionalists to report recent serodiscordant or unknown condomless anal sex and HIV risk management practices (e.g., ask their partner's HIV status, get tested for HIV). Traditionalists on the other hand were less likely to practice HIV risk management and had lower HIV/AIDS stigma scores than Socialites. Further, Traditionalists were older, more likely to be partnered, and reported fewer male sex partners than men in other groups. These findings highlight how patterns of connectedness relate to GBM's risk management.

Parent-Child Endorsement Discrepancies among Youth at Chronic-Risk for Depression.

PubMed

Makol, Bridget A; Polo, Antonio J

2017-11-10

Depression is one of the most common mental health problems among U.S. adolescents, particularly among Latinos. Parent-child ratings of the presence and severity of child depressive symptoms show only low-to-moderate agreement. However, research has failed to examine discrepancies in populations with the highest levels of unmet need and little is known about patterns and predictors of parent-child agreement in ratings of depressive symptoms among ethnic minority families in community settings. Using a sample of 184 low-income, predominantly Latino, 5th through 7th grade students (63.6% female) at chronic risk for depression, this study utilized exploratory Latent Class Analysis (LCA) to uncover patterns of parent-child endorsement of core diagnostic depressive symptoms. Overall, children reported higher levels of core (i.e., depressed mood, anhedonia, irritability) and secondary (e.g., sleep disturbances) depressive symptoms relative to their parents. The three latent classes identified include a low endorsement and high agreement class (LH), high endorsement and high agreement class (HH), and high child endorsement and low agreement class (HCL). Multinomial regression models revealed that previous mental health service use and higher externalizing problems were associated with HH class membership, relative to HCL class membership. Findings provide evidence that a substantial number of children may have depressive symptoms that go undetected by their parents. Access to services among children at-risk for depression may be increased with psychoeducation to improve parental awareness and stigma reduction.

Bioenergy production from perennial energy crops: a consequential LCA of 12 bioenergy scenarios including land use changes.

PubMed

Tonini, Davide; Hamelin, Lorie; Wenzel, Henrik; Astrup, Thomas

2012-12-18

In the endeavor of optimizing the sustainability of bioenergy production in Denmark, this consequential life cycle assessment (LCA) evaluated the environmental impacts associated with the production of heat and electricity from one hectare of Danish arable land cultivated with three perennial crops: ryegrass (Lolium perenne), willow (Salix viminalis) and Miscanthus giganteus. For each, four conversion pathways were assessed against a fossil fuel reference: (I) anaerobic co-digestion with manure, (II) gasification, (III) combustion in small-to-medium scale biomass combined heat and power (CHP) plants and IV) co-firing in large scale coal-fired CHP plants. Soil carbon changes, direct and indirect land use changes as well as uncertainty analysis (sensitivity, MonteCarlo) were included in the LCA. Results showed that global warming was the bottleneck impact, where only two scenarios, namely willow and Miscanthus co-firing, allowed for an improvement as compared with the reference (-82 and -45 t CO₂-eq. ha⁻¹, respectively). The indirect land use changes impact was quantified as 310 ± 170 t CO₂-eq. ha⁻¹, representing a paramount average of 41% of the induced greenhouse gas emissions. The uncertainty analysis confirmed the results robustness and highlighted the indirect land use changes uncertainty as the only uncertainty that can significantly change the outcome of the LCA results.

Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT)

PubMed Central

Cassiday, Pamela K.; Pawloski, Lucia C.; Tatti, Kathleen M.; Martin, Monte D.; Briere, Elizabeth C.; Tondella, M. Lucia; Martin, Stacey W.

2018-01-01

Introduction The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. Methods Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for ≤ 2 weeks were asked to return in 2–4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods—pertussis culture as the “gold standard,” composite reference standard analysis (CRS), and latent class analysis (LCA). Results Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. Conclusions Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis. PMID:29652945

A Watershed Scale Life Cycle Assessment Framework for Hydrologic Design

NASA Astrophysics Data System (ADS)

Tavakol-Davani, H.; Tavakol-Davani, PhD, H.; Burian, S. J.

2017-12-01

Sustainable hydrologic design has received attention from researchers with different backgrounds, including hydrologists and sustainability experts, recently. On one hand, hydrologists have been analyzing ways to achieve hydrologic goals through implementation of recent environmentally-friendly approaches, e.g. Green Infrastructure (GI) - without quantifying the life cycle environmental impacts of the infrastructure through the ISO Life Cycle Assessment (LCA) method. On the other hand, sustainability experts have been applying the LCA to study the life cycle impacts of water infrastructure - without considering the important hydrologic aspects through hydrologic and hydraulic (H&H) analysis. In fact, defining proper system elements for a watershed scale urban water sustainability study requires both H&H and LCA specialties, which reveals the necessity of performing an integrated, interdisciplinary study. Therefore, the present study developed a watershed scale coupled H&H-LCA framework to bring the hydrology and sustainability expertise together to contribute moving the current wage definition of sustainable hydrologic design towards onto a globally standard concept. The proposed framework was employed to study GIs for an urban watershed in Toledo, OH. Lastly, uncertainties associated with the proposed method and parameters were analyzed through a robust Monte Carlo simulation using parallel processing. Results indicated the necessity of both hydrologic and LCA components in the design procedure in order to achieve sustainability.

Typology of club drug use among young adults recruited using time-space sampling

PubMed Central

Ramo, Danielle E.; Grov, Christian; Delucchi, Kevin; Kelly, Brian C.; Parsons, Jeffrey T.

2009-01-01

The present study examined patterns of recent club drug use among 400 young adults (18–29) recruited using time-space sampling in NYC. Subjects had used at least one of six club drugs (MDMA, Ketamine, GHB, Cocaine, Methamphetamine, and LSD) within the prior 3 months. We used latent class analysis (LCA) to estimate latent groups based on patterns of recent club drug use and examined differences in demographic and psychological variables by class. A 3-class model fit the data best. Patterns were: Primary cocaine users (42% of sample), Mainstream users (44% of sample), and Wide-range users (14% of sample). Those most likely to be Primary cocaine users were significantly less likely to be heterosexual males and had higher educational attainment than the other two classes. Those most likely to be Wide-range users were less likely to be heterosexual females, more likely to be gay/bisexual males, dependent on club drugs, had significantly greater drug and sexual sensation-seeking, and were more likely to use when experiencing physical discomfort or pleasant times with others compared to the other two groups. Findings highlight the utility of using person-centered approaches to understand patterns of substance use, as well as highlight several patterns of club drug use among young adults. PMID:19939585

Improvement of the management of residual waste in areas without thermal treatment facilities: A life cycle analysis of an Italian management district

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

Di Maria, Francesco, E-mail: francesco.dimaria@unipg.it; Micale, Caterina; Morettini, Emanuela

2015-10-15

Highlights: • LCA analysis of two option for residual waste management. • Exploitation of mechanical physical sorting facility for extracting recyclable from RMSW. • Processing the mechanically sorted organic fraction in bioreactor landfill. • Sensitivity analysis demonstrate high influence for impact assessment of substitution ratio for recycle materials. - Abstract: Starting from an existing waste management district without thermal treatment facilities, two different management scenarios for residual waste were compared by life cycle assessment (LCA). The adoption of a bioreactor landfill for managing the mechanically sorted organic fraction instead of bio-stabilization led to reduction of global warming and fresh watermore » eutrophication by 50% and 10%, respectively. Extraction of recyclables from residual waste led to avoided emissions for particulate matter, acidification and resource depletion impact categories. Marginal energy and the amount of energy recovered from landfill gas marginally affected the LCA results. On the contrary the quality of the recyclables extracted can significantly modify the eco profile of the management schemes.« less

HIV-related sexual risk behavior among African American adolescent girls.

PubMed

Danielson, Carla Kmett; Walsh, Kate; McCauley, Jenna; Ruggiero, Kenneth J; Brown, Jennifer L; Sales, Jessica M; Rose, Eve; Wingood, Gina M; Diclemente, Ralph J

2014-05-01

Latent class analysis (LCA) is a useful statistical tool that can be used to enhance understanding of how various patterns of combined sexual behavior risk factors may confer differential levels of HIV infection risk and to identify subtypes among African American adolescent girls. Data for this analysis is derived from baseline assessments completed prior to randomization in an HIV prevention trial. Participants were African American girls (n=701) aged 14-20 years presenting to sexual health clinics. Girls completed an audio computer-assisted self-interview, which assessed a range of variables regarding sexual history and current and past sexual behavior. Two latent classes were identified with the probability statistics for the two groups in this model being 0.89 and 0.88, respectively. In the final multivariate model, class 1 (the "higher risk" group; n=331) was distinguished by a higher likelihood of >5 lifetime sexual partners, having sex while high on alcohol/drugs, less frequent condom use, and history of sexually transmitted diseases (STDs), when compared with class 2 (the "lower risk" group; n=370). The derived model correctly classified 85.3% of participants into the two groups and accounted for 71% of the variance in the latent HIV-related sexual behavior risk variable. The higher risk class also had worse scores on all hypothesized correlates (e.g., self-esteem, history of sexual assault or physical abuse) relative to the lower risk class. Sexual health clinics represent a unique point of access for HIV-related sexual risk behavior intervention delivery by capitalizing on contact with adolescent girls when they present for services. Four empirically supported risk factors differentiated higher versus lower HIV risk. Replication of these findings is warranted and may offer an empirical basis for parsimonious screening recommendations for girls presenting for sexual healthcare services.

Racial Differences in Partnership Attributes, Typologies, and Risk Behaviors Among Men Who Have Sex With Men in Atlanta, Georgia.

PubMed

White, Darcy; Grey, Jeremy A; Gorbach, Pamina M; Rothenberg, Richard B; Sullivan, Patrick S; Rosenberg, Eli S

2017-05-01

The role of main partnerships in shaping HIV transmission dynamics among men who have sex with men (MSM) has gained recognition in recent studies, but there is little evidence that existing definitions of partnership type are accurate or have consistent meaning for all men. Using data collected from 2011 to 2013 on 693 partnerships described by 193 Black and White MSM in Atlanta, GA, partnership attributes and risk behaviors were examined and compared by race, stratified in two ways: (1) by commonly used definitions of partnerships as "main" or "casual" and (2) by a new data-driven partnership typology identified through latent class analysis (LCA). Racial differences were analyzed using chi-square, Fisher's exact, and Wilcoxon-Mann-Whitney tests. Black participants were less likely to report condomless anal sex (CAS) within partnerships they labeled as main, yet they were also less likely to describe these partnerships as "primary" on a parallel question. In contrast, within strata defined by the LCA-derived typology, most partnership attributes were comparable and the likelihood of CAS was equivalent by race. These findings suggest that classification of partnerships as main or casual does not accurately capture the partnership patterns of MSM, resulting in differential misclassification by race. Future studies and interventions should refine and utilize more evidence-based typologies.

Is Science Me? Exploring Middle School Students' STE-M Career Aspirations

NASA Astrophysics Data System (ADS)

Aschbacher, Pamela R.; Ing, Marsha; Tsai, Sherry M.

2014-12-01

This study explores middle school students' aspirations in science, technology, engineering, and medical (STE-M) careers by analyzing survey data during their eighth and ninth grade years from an ethnically and economically diverse sample of Southern California urban and suburban public school students ( n = 493). Students were classified based on their responses to questions about their science ability beliefs and subjective task values using latent class analysis (LCA). Four distinct groups of students were identified: Science is Me; I Value Science But Don't Do It Well; I Can Do Science but I Don't Value It Highly; and Science is Not Me. Few students (22 %) were classified as having strong science ability beliefs, and only a third as strongly valuing learning/doing science; a majority (57 %) were in the Science is Not Me category, underscoring the scope of the challenge to invite more young people to want to learn science. As predicted, students who believed they could do science and valued science were more likely than others to indicate interest in STE-M careers. This relationship between perceptions and aspirations was true regardless of gender, ethnicity, and type of STE-M field, but varied depending on socioeconomic status. Using LCA to organize information about students' science self-perceptions may help target specific interventions to student interests and aspirations and better support and encourage their persistence in STE-M careers.

Interpreting ambiguous 'trace' results in Schistosoma mansoni CCA Tests: Estimating sensitivity and specificity of ambiguous results with no gold standard.

PubMed

Clements, Michelle N; Donnelly, Christl A; Fenwick, Alan; Kabatereine, Narcis B; Knowles, Sarah C L; Meité, Aboulaye; N'Goran, Eliézer K; Nalule, Yolisa; Nogaro, Sarah; Phillips, Anna E; Tukahebwa, Edridah Muheki; Fleming, Fiona M

2017-12-01

The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities. A point-of-care circulating cathodic antigen (CCA) test has been shown to be more sensitive than KK. However, CCA can return an ambiguous 'trace' result between 'positive' and 'negative', and much debate has focused on interpretation of traces results. We show how LCA can be extended to include ambiguous trace results and analyse S. mansoni studies from both Côte d'Ivoire (CdI) and Uganda. We compare the diagnostic performance of KK and CCA and the observed results by each test to the estimated infection prevalence in the population. Prevalence by KK was higher in CdI (13.4%) than in Uganda (6.1%), but prevalence by CCA was similar between countries, both when trace was assumed to be negative (CCAtn: 11.7% in CdI and 9.7% in Uganda) and positive (CCAtp: 20.1% in CdI and 22.5% in Uganda). The estimated sensitivity of CCA was more consistent between countries than the estimated sensitivity of KK, and estimated infection prevalence did not significantly differ between CdI (20.5%) and Uganda (19.1%). The prevalence by CCA with trace as positive did not differ significantly from estimates of infection prevalence in either country, whereas both KK and CCA with trace as negative significantly underestimated infection prevalence in both countries. Incorporation of ambiguous results into an LCA enables the effect of different treatment thresholds to be directly assessed and is applicable in many fields. Our results showed that CCA with trace as positive most accurately estimated infection prevalence.

Interpreting ambiguous ‘trace’ results in Schistosoma mansoni CCA Tests: Estimating sensitivity and specificity of ambiguous results with no gold standard

PubMed Central

Donnelly, Christl A.; Fenwick, Alan; Kabatereine, Narcis B.; Knowles, Sarah C. L.; Meité, Aboulaye; N'Goran, Eliézer K.; Nalule, Yolisa; Nogaro, Sarah; Phillips, Anna E.; Tukahebwa, Edridah Muheki; Fleming, Fiona M.

2017-01-01

Background The development of new diagnostics is an important tool in the fight against disease. Latent Class Analysis (LCA) is used to estimate the sensitivity and specificity of tests in the absence of a gold standard. The main field diagnostic for Schistosoma mansoni infection, Kato-Katz (KK), is not very sensitive at low infection intensities. A point-of-care circulating cathodic antigen (CCA) test has been shown to be more sensitive than KK. However, CCA can return an ambiguous ‘trace’ result between ‘positive’ and ‘negative’, and much debate has focused on interpretation of traces results. Methodology/Principle findings We show how LCA can be extended to include ambiguous trace results and analyse S. mansoni studies from both Côte d’Ivoire (CdI) and Uganda. We compare the diagnostic performance of KK and CCA and the observed results by each test to the estimated infection prevalence in the population. Prevalence by KK was higher in CdI (13.4%) than in Uganda (6.1%), but prevalence by CCA was similar between countries, both when trace was assumed to be negative (CCAtn: 11.7% in CdI and 9.7% in Uganda) and positive (CCAtp: 20.1% in CdI and 22.5% in Uganda). The estimated sensitivity of CCA was more consistent between countries than the estimated sensitivity of KK, and estimated infection prevalence did not significantly differ between CdI (20.5%) and Uganda (19.1%). The prevalence by CCA with trace as positive did not differ significantly from estimates of infection prevalence in either country, whereas both KK and CCA with trace as negative significantly underestimated infection prevalence in both countries. Conclusions Incorporation of ambiguous results into an LCA enables the effect of different treatment thresholds to be directly assessed and is applicable in many fields. Our results showed that CCA with trace as positive most accurately estimated infection prevalence. PMID:29220354

Sexual dysfunction in an Internet sample of U.S. men who have sex with men.

PubMed

Hirshfield, Sabina; Chiasson, Mary Ann; Wagmiller, Robert L; Remien, Robert H; Humberstone, Mike; Scheinmann, Roberta; Grov, Christian

2010-09-01

Relatively little is known about sexual dysfunction (SD) in men who have sex with men (MSM). In order to better understand SD symptoms in MSM, we assessed self-reported SD symptoms, individually and by latent class analysis (LCA). In 2004-2005 an Internet sample of U.S. MSM was recruited from gay-oriented sexual networking, chat and news websites. The analytic sample comprised 7,001 men aged 18 or older who reported lifetime male sex partners and oral or anal sex with a male partner in their most recent encounter within the past year. Seven questions on SD symptoms that occurred during the past 12 months inquired about low sexual desire, erection problems, inability to achieve an orgasm, performance anxiety, premature ejaculation, pain during sex, and sex not being pleasurable. Self-reported symptoms of SD were high. Overall, 79% of men reported one or more SD symptoms in the past year, with low sexual desire, erection problems, and performance anxiety being the most prevalent. Four distinct underlying patterns of sexual functioning were identified by LCA: no/low SD, erection problems/performance anxiety, low desire/pleasure, and high SD/sexual pain. High SD/sexual pain was distinguished from the other patterns by club drug use and use of prescription and non-prescription erectile dysfunction medication before sex in the past year. Additionally, men associated with the high SD/sexual pain group were younger, single, more likely to have poor mental and physical health, and more likely to have been diagnosed with a sexually transmitted infection in the past year compared to men in the no/low SD group. LCA enabled us to identify underlying patterns of sexual functioning among this sample of MSM recruited online. Future research should investigate these distinct subgroups with SD symptoms in order to develop tailored treatments and counseling for SD. © 2009 International Society for Sexual Medicine.

Retinoic acid‐induced glandular differentiation of the oesophagus

PubMed Central

Chang, Chih‐Long; Lao‐Sirieix, Pierre; Save, Vicki; De La Cueva Mendez, Guillermo; Laskey, Ron; Fitzgerald, Rebecca C

2007-01-01

Background Retinoic acid (RA) is a powerful differentiation agent. Barrett's oesophagus occurs when duodeno‐gastro‐oesophageal reflux causes squamous epithelium (SE) tissue to become columnar epithelium tissue by an unknown mechanism. The bile acid lithocholic acid (LCA) competes for the retinoid X receptor retinoid binding site. Hence, RA pathways may be implicated in Barrett's oesophagus. Methods RA activity in tissues and cell lines treated with all‐trans retinoic acid (ATRA) with or without LCA was assessed using a reporter. Expression of p21 was determined by real‐time PCR in Barrett's oesophagus cell lines with or without LCA. SE and Barrett's oesophagus biopsy specimens were exposed to 100 μM of ATRA or 20 mM of a RA inhibitor, citral, in organ culture for >72 h. Characteristics of treated specimens, compared with untreated controls, were analysed by immunohistochemical analysis (cytokeratins (CKs), vimentin) and RT‐PCR (CKs). Confocal microscopy assessed temporal changes in co‐localisation of CK8/18 and vimentin. Cell proliferation was assessed by bromo‐deoxyuridine incorporation and immunohistochemical analysis for Ki67 and p21. Results RA biosynthesis was increased in Barrett's oesophagus compared with SE (p<0.001). LCA and ATRA caused a synergistic increase in RA signalling as shown by increased p21 (p<0.01). Morphological and molecular analysis of SE exposed to ATRA showed columnar differentiation independent of proliferation. Metaplasia could be induced from the stromal compartment alone and vimentin expression co‐localised with CK8/18 at 24 h, which separated into CK8/18‐positive glands and vimentin‐positive stroma by 48 h. Citral‐treated Barrett's oesophagus led to phenotypic and immunohistochemical characteristics of SE, which was independent of proliferation. Conclusion RA activity is increased in Barrett's oesophagus and is induced by LCA. Under conditions of altered RA activity and an intact stroma, the oesophageal phenotype can be altered independent of proliferation. PMID:17185354

Profiles of youth in therapeutic group care: Associations with involuntary psychiatric examinations and readmissions.

PubMed

Yampolskaya, Svetlana; Mowery, Debra

2017-01-01

The study aims were to identify distinct subgroups among youth placed in therapeutic group care (TGC) and to examine the effect of specific constellations of risk factors on readmission to residential mental health care and involuntary psychiatric examination among youth in TGC. Several administrative databases were merged to examine outcomes for youth placed in TGC during fiscal year FY04-05 through FY07-08 (N = 1,009). Latent class analysis (LCA) was conducted. Two classes were identified: youth with multiple needs (Class 1) and lower risk youth (Class 2). Class 1 represented 45% of youth in TGC. Compared with Class 2, these youth had a greater probability of having physical health problems, parents with substance abuse problems, and more extensive histories of maltreatment. Compared with Class 2, youth with multiple needs were almost twice more likely to exhibit self-injurious behavior leading to involuntary mental health examinations, but they were less likely to be readmitted to a residential mental health care of higher level of restrictiveness, such as state inpatient psychiatric programs (SIPPs). Youth placed in Florida TGC represent a heterogeneous population and services tailored to these youth's needs are important. Youth with multiple risk factors would benefit from interventions that would address multiple areas of risk. Lower risk youth (Class 2) would benefit from interventions that would focus on promoting mental health, especially among those who have experienced threatened harm, and providing services and supports necessary for stabilizing these youth in the community. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Prevalence and co-occurrence of addictive behaviors among former alternative high school youth: A longitudinal follow-up study.

PubMed

Sussman, Steve; Pokhrel, Pallav; Sun, Ping; Rohrbach, Louise A; Spruijt-Metz, Donna

2015-09-01

Recent work has studied addictions using a matrix measure, which taps multiple addictions through single responses for each type. This is the first longitudinal study using a matrix measure. We investigated the use of this approach among former alternative high school youth (average age = 19.8 years at baseline; longitudinal n = 538) at risk for addictions. Lifetime and last 30-day prevalence of one or more of 11 addictions reviewed in other work was the primary focus (i.e., cigarettes, alcohol, hard drugs, shopping, gambling, Internet, love, sex, eating, work, and exercise). These were examined at two time-points one year apart. Latent class and latent transition analyses (LCA and LTA) were conducted in Mplus. Prevalence rates were stable across the two time-points. As in the cross-sectional baseline analysis, the 2-class model (addiction class, non-addiction class) fit the data better at follow-up than models with more classes. Item-response or conditional probabilities for each addiction type did not differ between time-points. As a result, the LTA model utilized constrained the conditional probabilities to be equal across the two time-points. In the addiction class, larger conditional probabilities (i.e., 0.40-0.49) were found for love, sex, exercise, and work addictions; medium conditional probabilities (i.e., 0.17-0.27) were found for cigarette, alcohol, other drugs, eating, Internet and shopping addiction; and a small conditional probability (0.06) was found for gambling. Persons in an addiction class tend to remain in this addiction class over a one-year period.

A latent class analysis of bullies, victims and aggressive victims in Chinese adolescence: relations with social and school adjustments.

PubMed

Shao, Aihui; Liang, Lichan; Yuan, Chunyong; Bian, Yufang

2014-01-01

This study used the latent class analysis (LCA) to identify and classify Chinese adolescent children's aggressive behaviors. It was found that (1) Adolescent children could be divided into four categories: general children, aggressive children, victimized children and aggressive victimized children. (2) There were significant gender differences among the aggressive victimized children, the aggressive children and the general children. Specifically, aggressive victimized children and aggressive children had greater probabilities of being boys; victimized children had equal probabilities of being boys or girls. (3) Significant differences in loneliness, depression, anxiety and academic achievement existed among the aggressive victims, the aggressor, the victims and the general children, in which the aggressive victims scored the worst in all questionnaires. (4) As protective factors, peer and teacher supports had important influences on children's aggressive and victimized behaviors. Relative to general children, aggressive victims, aggressive children and victimized children had lower probabilities of receiving peer supports. On the other hand, compared to general children, aggressive victims had lower probabilities of receiving teacher supports; while significant differences in the probability of receiving teacher supports did not exist between aggressive children and victimized children.

A Latent Class Analysis of Bullies, Victims and Aggressive Victims in Chinese Adolescence: Relations with Social and School Adjustments

PubMed Central

Shao, Aihui; Liang, Lichan; Yuan, Chunyong; Bian, Yufang

2014-01-01

This study used the latent class analysis (LCA) to identify and classify Chinese adolescent children's aggressive behaviors. It was found that (1) Adolescent children could be divided into four categories: general children, aggressive children, victimized children and aggressive victimized children. (2) There were significant gender differences among the aggressive victimized children, the aggressive children and the general children. Specifically, aggressive victimized children and aggressive children had greater probabilities of being boys; victimized children had equal probabilities of being boys or girls. (3) Significant differences in loneliness, depression, anxiety and academic achievement existed among the aggressive victims, the aggressor, the victims and the general children, in which the aggressive victims scored the worst in all questionaires. (4) As protective factors, peer and teacher supports had important influences on children's aggressive and victimized behaviors. Relative to general children, aggressive victims, aggressive children and victimized children had lower probabilities of receiving peer supports. On the other hand, compared to general children, aggressive victims had lower probabilities of receiving teacher supports; while significant differences in the probability of receiving teacher supports did not exist between aggressive children and victimized children. PMID:24740096

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

Hoogmartens, Rob, E-mail: rob.hoogmartens@uhasselt.be; Van Passel, Steven, E-mail: steven.vanpassel@uhasselt.be; Van Acker, Karel, E-mail: karel.vanacker@lrd.kuleuven.be

Increasing interest in sustainability has led to the development of sustainability assessment tools such as Life Cycle Analysis (LCA), Life Cycle Costing (LCC) and Cost–Benefit Analysis (CBA). Due to methodological disparity of these three tools, conflicting assessment results generate confusion for many policy and business decisions. In order to interpret and integrate assessment results, the paper provides a framework that clarifies the connections and coherence between the included assessment methodologies. Building on this framework, the paper further focuses on key aspects to adapt any of the methodologies to full sustainability assessments. Aspects dealt with in the review are for examplemore » the reported metrics, the scope, data requirements, discounting, product- or project-related and approaches with respect to scarcity and labor requirements. In addition to these key aspects, the review shows that important connections exist: (i) the three tools can cope with social inequality, (ii) processes such as valuation techniques for LCC and CBA are common, (iii) Environmental Impact Assessment (EIA) is used as input in both LCA and CBA and (iv) LCA can be used in parallel with LCC. Furthermore, the most integrated sustainability approach combines elements of LCA and LCC to achieve the Life Cycle Sustainability Assessment (LCSA). The key aspects and the connections referred to in the review are illustrated with a case study on the treatment of end-of-life automotive glass. - Highlights: • Proliferation of assessment tools creates ambiguity and confusion. • The developed assessment framework clarifies connections between assessment tools. • Broadening LCA, key aspects are metric and data requirements. • Broadening LCC, key aspects are scope, time frame and discounting. • Broadening CBA, focus point, timespan, references, labor and scarcity are key.« less

Life cycle energy and greenhouse gas emission effects of biodiesel in the United States with induced land use change impacts

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

Chen, Rui; Qin, Zhangcai; Han, Jeongwoo

This study conducted the updated simulations to depict a life cycle analysis (LCA) of the biodiesel production from soybeans and other feedstocks in the U.S. It addressed in details the interaction between LCA and induced land use change (ILUC) for biodiesel. Relative to the conventional petroleum diesel, soy biodiesel could achieve 76% reduction in GHG emissions without considering ILUC, or 66-72% reduction in overall GHG emissions when various ILUC cases were considered. Soy biodiesel’s fossil fuel consumption rate was also 80% lower than its petroleum counterpart. Furthermore, this study examined the cause and the implication of each key parameter affectingmore » biodiesel LCA results using a sensitivity analysis, which identified the hot spots for fossil fuel consumption and GHG emissions of biodiesel so that future efforts can be made accordingly. Finally, biodiesel produced from other feedstocks (canola oil and tallow) were also investigated to contrast with soy biodiesel and petroleum diesel« less

How best to obtain consent to thrombolysis: Individualized decision-making.

PubMed

Gong, Jingjing; Zhang, Yan; Feng, Jun; Zhang, Weiwei; Yin, Weimin; Wu, Xinhuai; Hou, Yanhong; Huang, Yonghua; Liu, Hongyun; Miao, Danmin

2016-03-15

To investigate the factors that influence the preferences of patients and their proxies concerning thrombolytic therapy and to determine how best to convey information. A total of 613 participants were randomly assigned to a positively or negatively framed group. Each participant completed a series of surveys. We applied latent class analysis (LCA) to explore participants' patterns of choices of thrombolysis and to classify the participants into different subgroups. Then we performed regression analyses to investigate predictors of classification of the participants into each subgroup and to establish a thrombolytic decision-making model. LCA indicated an optimal 3-subgroup model comprising intermediate, favorable to thrombolysis, and aversion to thrombolysis subgroups. Multiple regression analysis revealed that 10 factors predicted assignment to the intermediate subgroup and 4 factors predicted assignment to the aversion to thrombolysis subgroup compared with the favorable to thrombolysis subgroup. The χ(2) tests indicated that the information presentation format and the context of thrombolysis influenced participants' choices of thrombolysis and revealed a framing effect in different subgroups. The preference for thrombolysis was influenced by the positive vs negative framing scenarios, the format of item presentation, the context of thrombolysis, and individual characteristics. Inconsistent results may be due to participant heterogeneity and the evaluation of limited factors in previous studies. Based on a decision model of thrombolysis, physicians should consider the effects of positive vs negative framing and should seek a neutral tone when presenting the facts, providing an important reference point for health persuasion in other clinical domains. © 2016 American Academy of Neurology.

Job Demand and Job Satisfaction in Latent Groups of Turnover Intention Among Licensed Nurses in Taiwan Nursing Homes.

PubMed

Chen, I-Hui; Brown, Roger; Bowers, Barbara J; Chang, Wen-Yin

2015-10-01

Nurses' turnover intention is not dichotomous; it may reflect intent to leave the profession, intent to leave a type of facility, or intent to leave a specific workplace. In a latent class analysis (LCA) of data from 186 licensed nurses (RNs and LPNs) recruited from 25 nursing homes (NHs) in Taiwan, we classified nurses into turnover intention subgroups based on seven questionnaire items and used a multilevel contrast analysis to characterize the subgroups according to demographic and facility factors, job demand, and job satisfaction. A multilevel probit model was used to examine how job demand and job satisfaction influenced subgroup membership. Three turnover subgroups were identified: high turnover intention (12%), middle turnover intention (57%), and low turnover intention (31%). The high turnover intention subgroup comprised the youngest nurses and had the lowest percentage of registered nurses (RNs); nurses in this subgroup had worked the longest at the current NH and had the greatest likelihood of working at a for-profit facility. Nurses in the middle turnover intention subgroup had the lowest likelihood of working at a for-profit facility. Nurses in the low turnover intention subgroup were primarily RNs and had the shortest work experience in the current facility. Nurses in the high and middle turnover intention subgroups reported lower intrinsic job satisfaction than those with low turnover intention. Extrinsic job satisfaction mediated the relationship between job demand and turnover intention subgroup assignment. The results of this LCA can help target interventions to address heterogeneity of turnover intention and ultimately lessen turnover. © 2015 Wiley Periodicals, Inc.

LCA – Unique and Controversial Case Studies

EPA Science Inventory

This session will focus on case studies and applications that have a unique or controversial aspect. Some of the most recent topics that seem to have significant interest include: LCA-based product declarations, LCA-based standards, LCA-based labels, alternative energy, agricul...

Transportation Life Cycle Assessment (LCA) Synthesis, Phase II

DOT National Transportation Integrated Search

2018-04-24

The Transportation Life Cycle Assessment (LCA) Synthesis includes an LCA Learning Module Series, case studies, and analytics on the use of the modules. The module series is a set of narrated slideshows on topics related to environmental LCA. Phase I ...

Global and local health burden trade-off through the hybridisation of quantitative microbial risk assessment and life cycle assessment to aid water management.

PubMed

Kobayashi, Yumi; Peters, Greg M; Ashbolt, Nicholas J; Heimersson, Sara; Svanström, Magdalena; Khan, Stuart J

2015-08-01

Life cycle assessment (LCA) and quantitative risk assessment (QRA) are commonly used to evaluate potential human health impacts associated with proposed or existing infrastructure and products. Each approach has a distinct objective and, consequently, their conclusions may be inconsistent or contradictory. It is proposed that the integration of elements of QRA and LCA may provide a more holistic approach to health impact assessment. Here we examine the possibility of merging LCA assessed human health impacts with quantitative microbial risk assessment (QMRA) for waterborne pathogen impacts, expressed with the common health metric, disability adjusted life years (DALYs). The example of a recent large-scale water recycling project in Sydney, Australia was used to identify and demonstrate the potential advantages and current limitations of this approach. A comparative analysis of two scenarios - with and without the development of this project - was undertaken for this purpose. LCA and QMRA were carried out independently for the two scenarios to compare human health impacts, as measured by DALYs lost per year. LCA results suggested that construction of the project would lead to an increased number of DALYs lost per year, while estimated disease burden resulting from microbial exposures indicated that it would result in the loss of fewer DALYs per year than the alternative scenario. By merging the results of the LCA and QMRA, we demonstrate the advantages in providing a more comprehensive assessment of human disease burden for the two scenarios, in particular, the importance of considering the results of both LCA and QRA in a comparative assessment of decision alternatives to avoid problem shifting. The application of DALYs as a common measure between the two approaches was found to be useful for this purpose. Copyright © 2015 Elsevier Ltd. All rights reserved.

Co-occurrence of Victimization from Five Subtypes of Bullying: Physical, Verbal, Social Exclusion, Spreading Rumors, and Cyber

PubMed Central

Iannotti, Ronald J.; Luk, Jeremy W.; Nansel, Tonja R.

2010-01-01

Objective To examine co-occurrence of five subtypes of peer victimization. Methods Data were obtained from a national sample of 7,475 US adolescents in grades 6 through 10 in the 2005/2006 Health Behavior in School-Aged Children (HBSC) study. Latent class analyses (LCA) were conducted on victimization by physical, verbal, social exclusion, spreading rumors, and cyber bullying. Results Three latent classes were identified, including an all-types victims class (9.7% of males and 6.2% of females), a verbal/relational victims class (28.1% of males and 35.1% of females), and a nonvictim class (62.2% of males and 58.7% of females). Males were more likely to be all-type victims. There was a graded relationship between the three latent classes and level of depression, frequency of medically attended injuries, and medicine use, especially among females. Conclusions  Increased co-occurrence of victimization types put adolescents at greater risks for poorer physical and psychological outcomes. PMID:20488883

The C terminus of the catalytic domain of type A botulinum neurotoxin may facilitate product release from the active site.

PubMed

Mizanur, Rahman M; Frasca, Verna; Swaminathan, Subramanyam; Bavari, Sina; Webb, Robert; Smith, Leonard A; Ahmed, S Ashraf

2013-08-16

Botulinum neurotoxins are the most toxic of all compounds. The toxicity is related to a poor zinc endopeptidase activity located in a 50-kDa domain known as light chain (Lc) of the toxin. The C-terminal tail of Lc is not visible in any of the currently available x-ray structures, and it has no known function but undergoes autocatalytic truncations during purification and storage. By synthesizing C-terminal peptides of various lengths, in this study, we have shown that these peptides competitively inhibit the normal catalytic activity of Lc of serotype A (LcA) and have defined the length of the mature LcA to consist of the first 444 residues. Two catalytically inactive mutants also inhibited LcA activity. Our results suggested that the C terminus of LcA might interact at or near its own active site. By using synthetic C-terminal peptides from LcB, LcC1, LcD, LcE, and LcF and their respective substrate peptides, we have shown that the inhibition of activity is specific only for LcA. Although a potent inhibitor with a Ki of 4.5 μm, the largest of our LcA C-terminal peptides stimulated LcA activity when added at near-stoichiometric concentration to three versions of LcA differing in their C-terminal lengths. The result suggested a product removal role of the LcA C terminus. This suggestion is supported by a weak but specific interaction determined by isothermal titration calorimetry between an LcA C-terminal peptide and N-terminal product from a peptide substrate of LcA. Our results also underscore the importance of using a mature LcA as an inhibitor screening target.

Antisense Oligonucleotide (AON)-based Therapy for Leber Congenital Amaurosis Caused by a Frequent Mutation in CEP290

PubMed Central

Collin, Rob WJ; den Hollander, Anneke I; van der Velde-Visser, Saskia D; Bennicelli, Jeannette; Bennett, Jean; Cremers, Frans PM

2012-01-01

Leber congenital amaurosis (LCA) is the most severe form of inherited retinal degeneration, with an onset in the first year of life. The most frequent mutation that causes LCA, present in at least 10% of individuals with LCA from North-American and Northern-European descent, is an intronic mutation in CEP290 that results in the inclusion of an aberrant exon in the CEP290 mRNA. Here, we describe a genetic therapy approach that is based on antisense oligonucleotides (AONs), small RNA molecules that are able to redirect normal splicing of aberrantly processed pre-mRNA. Immortalized lymphoblastoid cells of individuals with LCA homozygously carrying the intronic CEP290 mutation were transfected with several AONs that target the aberrant exon that is incorporated in the mutant CEP290 mRNA. Subsequent RNA isolation and reverse transcription-PCR analysis revealed that a number of AONs were capable of almost fully redirecting normal CEP290 splicing, in a dose-dependent manner. Other AONs however, displayed no effect on CEP290 splicing at all, indicating that the rescue of aberrant CEP290 splicing shows a high degree of sequence specificity. Together, our data show that AON-based therapy is a promising therapeutic approach for CEP290-associated LCA that warrants future research in animal models to develop a cure for this blinding disease. PMID:23343883

Assessing the Economic and Environmental Impacts Associated with Current Street Lighting Technologies

DTIC Science & Technology

2010-03-01

AFIT/GEM/ENV/10-M01 Abstract Rising global energy demand and natural disasters continuously threaten energy supplies and prices. As a result , the...light bulbs. The study used the Process-Sum and Economic Input-Output Life-cycle Assessment (EIO- LCA ) methods. The results of the study found that... results for this phase of the analysis. Summary This chapter has detailed the methodology used in this study. Using both LCCA and EIO- LCA allowed for

A regional scale modeling framework combining biogeochemical model with life cycle and economic analysis for integrated assessment of cropping systems.

PubMed

Tabatabaie, Seyed Mohammad Hossein; Bolte, John P; Murthy, Ganti S

2018-06-01

The goal of this study was to integrate a crop model, DNDC (DeNitrification-DeComposition), with life cycle assessment (LCA) and economic analysis models using a GIS-based integrated platform, ENVISION. The integrated model enables LCA practitioners to conduct integrated economic analysis and LCA on a regional scale while capturing the variability of soil emissions due to variation in regional factors during production of crops and biofuel feedstocks. In order to evaluate the integrated model, the corn-soybean cropping system in Eagle Creek Watershed, Indiana was studied and the integrated model was used to first model the soil emissions and then conduct the LCA as well as economic analysis. The results showed that the variation in soil emissions due to variation in weather is high causing some locations to be carbon sink in some years and source of CO 2 in other years. In order to test the model under different scenarios, two tillage scenarios were defined: 1) conventional tillage (CT) and 2) no tillage (NT) and analyzed with the model. The overall GHG emissions for the corn-soybean cropping system was simulated and results showed that the NT scenario resulted in lower soil GHG emissions compared to CT scenario. Moreover, global warming potential (GWP) of corn ethanol from well to pump varied between 57 and 92gCO 2 -eq./MJ while GWP under the NT system was lower than that of the CT system. The cost break-even point was calculated as $3612.5/ha in a two year corn-soybean cropping system and the results showed that under low and medium prices for corn and soybean most of the farms did not meet the break-even point. Copyright © 2017 Elsevier B.V. All rights reserved.

Differences of Longitudinal Chromatic Aberration (LCA) between Eyes with Intraocular Lenses from Different Manufacturers.

PubMed

Nakajima, Masashi; Hiraoka, Takahiro; Yamamoto, Toshiya; Takagi, Seiu; Hirohara, Yoko; Oshika, Tetsuro; Mihashi, Toshifumi

2016-01-01

Several researchers have studied the longitudinal chromatic aberration (LCA) of eyes implanted with an intraocular lens (IOL). We investigated the LCA of eyes implanted with yellow-colored IOLs from three different manufacturers: Alcon Inc., HOYA Corp., and AMO Inc. The number of subjects was 11, 16, and 16, respectively. The LCA of eyes implanted with SN60WF and SN60AT (Alcon Inc.), and with XY-1 (HOYA Corp.), was the same as that of phakic eyes. The LCA of eyes with ZCB00V (AMO Inc.) was smaller than that of phakic eyes. The LCA of eyes implanted with Alcon's and HOYA's IOLs, but not the LCA of eyes implanted with AMO's IOLs, was positively correlated with the powers of the IOLs. We also performed simulations to verify the impacts of LCA on visual performance for 4-mm pupil diameter; the simulations were a polychromatic modulation transfer function (MTF) and a visual Strehl ratio computed on the basis of an optical transfer function (VSOTF). We concluded that the differences between the LCA of different manufacturers do not affect visual performances when some extent of higher-order aberration (HOA) exists. The smaller HOA of AMO IOLs may enhance visual performance.

NREL: U.S. Life Cycle Inventory Database - Related Links

Science.gov Websites

) information, LCA tools, research institutes utilizing LCA, labeling initiatives and organizations , international LCA initiatives, LCA online forums. Life Cycle Inventory Data Ecoinvent: Swiss Centre for Life Institute for Environmental Research and Education): The American Center for Life Cycle Assessment SETAC

Noise in DORIS station position time series provided by IGN-JPL, INASAN and CNES-CLS Analysis Centres for the ITRF2014 realization

NASA Astrophysics Data System (ADS)

Khelifa, Sofiane

2016-12-01

The purpose of this paper is to compare the noise characteristics in DORIS station positions between the three solutions derived by IGN-JPL (named as IGN), INASAN (named as INA) and CNES-CLS (named as LCA) Analysis Centres for ITRF2014 contribution, and to evaluate the improvements of these reprocessed solutions in terms of noise level with the previous ITRF2008 solutions. To the weekly STCD (STation Coordinate Difference) residual position time series of 23 stations referred to ITRF2008 and expressed in the local frame (North, East and Up), we calculated the Allan variance to identify their noise type, and applied the wavelet transform to assess their annual and semi-annual signals, and their noise level. The results reveal that the three solutions are dominated by white noise in all three components. The noise level is the lowest in the LCA solution; the average noise level in respectively, North, East and Vertical components is around 5.9 mm, 9.3 mm and 6.6 mm for LCA, 9 mm, 11.6 mm and 9 mm for IGN, and 8.7 mm, 11.6 mm and 9.1 mm for INA. The results also show that the tropical (±23.5°) stations are more distorted than mid-latitude and high latitude stations. In terms of noise level, the reprocessed LCA solution (lca14wd40) and its previous solution (lca11wd02) converge to similar results, while the reprocessed IGN (ign14wd15) and INA (ina14wd08) solutions show improvements with respect to their previous solutions (ign11wd01) and (ina12wd01) respectively, especially in the East component. Furthermore, the possible origin of the estimated annual signal was also investigated by comparing it with hydrology and atmospheric loading displacements. The annual Vertical component for the three solutions is more correlated with the GLDAS/Noah hydrology model with an average correlation of about 0.35, and shows a strong correlation of about 0.76 with ECMWF-IB and ECMWF-MOG2D atmospheric models for the station Krasnoyarsk (KRBB) in Siberia.

Paper waste - recycling, incineration or landfilling? A review of existing life cycle assessments.

PubMed

Villanueva, A; Wenzel, H

2007-01-01

A review of existing life cycle assessments (LCAs) on paper and cardboard waste has been undertaken. The objectives of the review were threefold. Firstly, to see whether a consistent message comes out of published LCA literature on optimum disposal or recycling solutions for this waste type. Such message has implications for current policy formulation on material recycling and disposal in the EU. Secondly, to identify key methodological issues of paper waste management LCAs, and enlighten the influence of such issues on the conclusions of the LCA studies. Thirdly, in light of the analysis made, to discuss whether it is at all valid to use the LCA methodology in its current development state to guide policy decisions on paper waste. A total of nine LCA studies containing altogether 73 scenarios were selected from a thorough, international literature search. The selected studies are LCAs including comparisons of different management options for waste paper. Despite claims of inconsistency, the LCAs reviewed illustrate the environmental benefits in recycling over incineration or landfill options, for paper and cardboard waste. This broad consensus was found despite differences in geographic location and definitions of the paper recycling/disposal systems studied. A systematic exploration of the LCA studies showed, however, important methodological pitfalls and sources of error, mainly concerning differences in the definition of the system boundaries. Fifteen key assumptions were identified that cover the three paper cycle system areas: raw materials and forestry, paper production, and disposal/recovery. It was found that the outcome of the individual LCA studies largely depended on the choices made in some of these assumptions, most specifically the ones concerning energy use and generation, and forestry.

Workshop on LCA: Methodology, Current Development, and Application in Standards - LCA Methodology

EPA Science Inventory

As ASTM standards are being developed including Life Cycle Assessment within the Standards it is imperative that practitioners in the field learn more about what LCA is, and how to conduct it. This presentation will include an overview of the LCA process and will concentrate on ...

Latent class analysis to evaluate performance of point-of-care CCA for low-intensity Schistosoma mansoni infections in Burundi.

PubMed

Clements, Michelle N; Corstjens, Paul L A M; Binder, Sue; Campbell, Carl H; de Dood, Claudia J; Fenwick, Alan; Harrison, Wendy; Kayugi, Donatien; King, Charles H; Kornelis, Dieuwke; Ndayishimiye, Onesime; Ortu, Giuseppina; Lamine, Mariama Sani; Zivieri, Antonio; Colley, Daniel G; van Dam, Govert J

2018-02-23

Kato-Katz examination of stool smears is the field-standard method for detecting Schistosoma mansoni infection. However, Kato-Katz misses many active infections, especially of light intensity. Point-of-care circulating cathodic antigen (CCA) is an alternative field diagnostic that is more sensitive than Kato-Katz when intensity is low, but interpretation of CCA-trace results is unclear. To evaluate trace results, we tested urine and stool specimens from 398 pupils from eight schools in Burundi using four approaches: two in Burundi and two in a laboratory in Leiden, the Netherlands. In Burundi, we used Kato-Katz and point-of-care CCA (CCAB). In Leiden, we repeated the CCA (CCAL) and also used Up-Converting Phosphor Circulating Anodic Antigen (CAA). We applied Bayesian latent class analyses (LCA), first considering CCA traces as negative and then as positive. We used the LCA output to estimate validity of the prevalence estimates of each test in comparison to the population-level infection prevalence and estimated the proportion of trace results that were likely true positives. Kato-Katz yielded the lowest prevalence (6.8%), and CCAB with trace considered positive yielded the highest (53.5%). There were many more trace results recorded by CCA in Burundi (32.4%) than in Leiden (2.3%). Estimated prevalence with CAA was 46.5%. LCA indicated that Kato-Katz had the lowest sensitivity: 15.9% [Bayesian Credible Interval (BCI): 9.2-23.5%] with CCA-trace considered negative and 15.0% with trace as positive (BCI: 9.6-21.4%), implying that Kato-Katz missed approximately 85% of infections. CCAB underestimated disease prevalence when trace was considered negative and overestimated disease prevalence when trace was considered positive, by approximately 12 percentage points each way, and CAA overestimated prevalence in both models. Our results suggest that approximately 52.2% (BCI: 37.8-5.8%) of the CCAB trace readings were true infections. Whether measured in the laboratory or the field, CCA outperformed Kato-Katz at the low infection intensities in Burundi. CCA with trace as negative likely missed many infections, whereas CCA with trace as positive overestimated prevalence. In the absence of a field-friendly gold standard diagnostic, the use of a variety of diagnostics with differing properties will become increasingly important as programs move towards elimination of schistosomiasis. It is clear that CCA is a valuable tool for the detection and mapping of S. mansoni infection in the field and CAA may be a valuable field tool in the future.

Life cycle approaches to sustainable consumption: a critical review.

PubMed

Hertwich, Edgar G

2005-07-01

The 2002 World Summit for Sustainable Development in Johannesburg called for a comprehensive set of programs focusing on sustainable consumption and production. According to world leaders, these programs should rely on life cycle assessment (LCA) to promote sustainable patterns of production and consumption. Cleaner production is a well-established activity, and it uses LCA. UNEP, the European Union, and a number of national organizations have now begun to work on sustainable consumption. In developing sustainable consumption policies and activities, the use of LCA presents interesting opportunities that are not yet well understood by policy makers. This paper reviews how life cycle approaches, primarily based on input-output analysis, have been used in the area of sustainable consumption: to inform policy making, select areas of action, identify which lifestyles are more sustainable, advise consumers, and evaluate the effectiveness of sustainable consumption measures. Information on consumption patterns usually comes from consumer expenditure surveys. Different study designs and a better integration with consumer research can provide further interesting insights. Life-cycle approaches still need to be developed and tested. Current research is mostly descriptive; policy makers, however, require more strategic analysis addressing their decision options, including scenario analysis and backcasting.

Application of Life Cycle Assessment (LCA) in Sugar Industries

NASA Astrophysics Data System (ADS)

Astuti, Arieyanti Dwi; Astuti, Rahayu Siwi Dwi; Hadiyanto, Hadiyanto

2018-02-01

Sugar is one of the main commodities that are needed for human life. The demand of sugar is very high with the trend increase from year to year. This condition makes the sugar industry become a leading industry that must be maintained sustainability. The sustainability of the sugar industry is influenced by the use of energy and natural resources and the resulting environmental impacts. Therefore, an effort is needed to analyze the environmental aspects and potential environmental impacts resulting from a product (sugar), by using Life Cycle Assessment (LCA). LCA is a very important tool for the analysis of a process/system from its cradle to grave. This technique is very useful in the estimation of energy usage and environmental load of a product/system. This paper aims to describe the main elements of sugar industries using Life Cycle Assessment.

LIFE CYCLE ASSESSMENT IN MANAGEMENT, PRODUCT AND PROCESS DESIGN, AND POLICY DECISION MAKING: A CONFERENCE REPORT

EPA Science Inventory

On 24 September 2003, life cycle assessment (LCA) practitioners and decision makers gathered at the InLCA/LCM Conference in Seattle, Washington, USA (see http://www.lcacenter.org/InLCA-LCM03/index.html) to discuss the role of LCA in management, product design, process development...

A global prospective of income distribution and its effect on life cycle assessment of municipal solid waste management: a review.

PubMed

Yadav, Pooja; Samadder, S R

2017-04-01

This study reviewed the municipal solid waste (MSW) composition, the management practices, and the use of life cycle assessment (LCA) tool for MSW management (MSWM) options in the various income group countries. LCA studies require inventory data, which is difficult to procure for any country including higher income group countries, and this issue gets compounded in low-income and lower middle-income group countries, which limits the implementation of LCA. This paper compared the use of LCA for MSWM between high-income and low-income group countries and also highlights the gap in using LCA for MSWM. A very limited number of LCA studies on MSWM were found for low-income group countries in comparison to high-income group countries. The study also provided a critical discussion on the challenges in applications of LCA in MSWM for better solid waste management in low-income and lower middle-income group countries. The study will help in taking up LCA studies in low-income countries to improve the overall MSWM efficiency.

Latent class analysis of acceptability and willingness to pay for self-HIV testing in a United States urban neighbourhood with high rates of HIV infection.

PubMed

Nunn, Amy; Brinkley-Rubinstein, Lauren; Rose, Jennifer; Mayer, Kenneth; Stopka, Thomas; Towey, Caitlin; Harvey, Julia; Santamaria, Karina; Sabatino, Kelly; Trooskin, Stacey; Chan, Philip A

2017-01-17

Acceptability and willingness to both take and pay for HIV self-tests (HIVSTs) in US neighbourhoods with high rates of HIV infection are not well understood. We surveyed 1,535 individuals about acceptability and willingness to take and pay for an HIVST in a predominately African American neighbourhood with 3% HIV seroprevalence. We recruited individuals presenting for HIV screening services in a community-based programme. Latent class analysis (LCA) grouped individuals with similar patterns of HIV-risk behaviours and determined which groups would be most willing to use and buy HIVSTs. Nearly 90% of respondents were willing to use an HIVST; 55% were willing to buy HIVSTs, but only 23% were willing to pay the market price of US $40. Four distinct groups emerged and were characterized by risk behaviours: (1) low risk ( N  = 324); (2) concurrent partnerships ( N  = 346); (3) incarceration and substance use ( N  = 293); and (4) condomless sex/multiple partners ( N  = 538). Individuals in the low-risk class were less willing to self-test compared to concurrent sexual partners (OR = 0.39, p  = .003) and incarceration and substance use (OR = 0.46, p  = .011) classes. There were no significant differences across classes in the amount individuals were willing to pay for an HIVST. HIVSTs were overwhelmingly acceptable but cost prohibitive; most participants were unwilling to pay the market rate of US $40. Subsidizing and implementing HIVST programmes in communities with high rates of infection present a public health opportunity, particularly among individuals reporting condomless sex with multiple partners, concurrent sexual partnerships and those with incarceration and substance use histories.

Differences of Longitudinal Chromatic Aberration (LCA) between Eyes with Intraocular Lenses from Different Manufacturers

PubMed Central

Nakajima, Masashi; Hiraoka, Takahiro; Yamamoto, Toshiya; Takagi, Seiu; Hirohara, Yoko; Oshika, Tetsuro

2016-01-01

Several researchers have studied the longitudinal chromatic aberration (LCA) of eyes implanted with an intraocular lens (IOL). We investigated the LCA of eyes implanted with yellow-colored IOLs from three different manufacturers: Alcon Inc., HOYA Corp., and AMO Inc. The number of subjects was 11, 16, and 16, respectively. The LCA of eyes implanted with SN60WF and SN60AT (Alcon Inc.), and with XY-1 (HOYA Corp.), was the same as that of phakic eyes. The LCA of eyes with ZCB00V (AMO Inc.) was smaller than that of phakic eyes. The LCA of eyes implanted with Alcon’s and HOYA’s IOLs, but not the LCA of eyes implanted with AMO’s IOLs, was positively correlated with the powers of the IOLs. We also performed simulations to verify the impacts of LCA on visual performance for 4-mm pupil diameter; the simulations were a polychromatic modulation transfer function (MTF) and a visual Strehl ratio computed on the basis of an optical transfer function (VSOTF). We concluded that the differences between the LCA of different manufacturers do not affect visual performances when some extent of higher-order aberration (HOA) exists. The smaller HOA of AMO IOLs may enhance visual performance. PMID:27258141

Network meta-analysis of probiotics to prevent respiratory infections in children and adolescents.

PubMed

Amaral, Marina Azambuja; Guedes, Gabriela Helena Barbosa Ferreira; Epifanio, Matias; Wagner, Mario Bernardes; Jones, Marcus Herbert; Mattiello, Rita

2017-06-01

Probiotics have emerged as a promising intervention for the prevention of respiratory tract infections (RTIs) in children. Assess the effect of probiotics on prevention of RTIs in children and adolescents. MEDLINE, EMBASE, LILACS, SCIELO, CINAHL, SCOPUS, and Web of Science. Key words: "respiratory tract infections" AND probiotics. Randomized controlled trials RCT assessing the effect of probiotics on RTIs in children and adolescents were included. Two reviewers, working independently, to identify studies that met the eligibility criteria. Main and secondary outcomes were RTIs and adverse effects, respectively. Twenty-one trials with 6.603 participants were included. Pairwise meta-analysis suggested that Lactobacillus casei rhamnosus (LCA) was the only effective probiotic to the rate of RTIs compared to placebo (RR0.38; Crl 0.19-0.45). Network analysis showed that the LCA exhibited 54.7% probability of being classified in first, while the probability of Lactobacillus fermentum CECT5716 (LFC) being last in the ranking was 15.3%. LCA showed no better effect compared to other probiotic strains by indirect analysis. This systematic review found a lack of evidence to support the effect of probiotic on the incidence rate of respiratory infections in children and adolescents. Pediatr Pulmonol. 2017;52:833-843. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The impact of patterns of trauma exposure among low income children with and without histories of child maltreatment.

PubMed

Rosen, Abigail L; Handley, Elizabeth D; Cicchetti, Dante; Rogosch, Fred A

2018-06-01

Previous research has revealed a large prevalence of trauma experienced by children, creating high risk for the development of psychopathology. Research investigating the negative impacts of child maltreatment and other traumas has typically examined these experiences individually, controlling for co-occurring traumas, or has combined these experiences into a general variable of risk, thereby obscuring the complex relationships among environmental traumas and maltreatment. The current study expands on previous research by elucidating relationships between multiple contexts of overlapping traumas and maltreatment experienced by children, and by categorizing how these experiences join together to impact internalizing and externalizing symptomatology. Participants included 316 maltreated children and 269 nonmaltreated children (M age = 9.4, SD = 0.88) who attended a summer day camp research program for low-income children. Latent Class Analysis (LCA) identified three differential patterns of trauma exposure across children: 1) community violence and loss; 2) pervasive trauma; and 3) low trauma. Covariate analyses demonstrated that child maltreatment was significantly associated with class membership, suggesting that maltreated children were more likely to experience diverse traumas extending beyond their maltreatment experiences (pervasive trauma class). A two-way analysis of variance also demonstrated that trauma latent class membership and child maltreatment each represented unique predictors of internalizing and externalizing symptoms, with each having an independent effect on symptomatology. This investigation provides unique insight into the differential impact of patterns of trauma exposure and child maltreatment, providing support for further research and clinical practice addressing multiple levels of a child's ecology. Copyright © 2018 Elsevier Ltd. All rights reserved.

Classes of Psychotic Experiences in Kenyan Children and Adolescents

PubMed Central

Owoso, Akinkunle; Mbwayo, Anne W.; Mutiso, Victoria N.; Muriungi, Susan K.; Khasakhala, Lincoln I.; Barch, Deanna M.; Ndetei, David M.

2012-01-01

Psychotic-like experiences (PLEs) have been observed worldwide in both adults and children outside the context of a clinical disorder. In the current study, we investigate the prevalence and patterns of PLEs among children and adolescents in Kenya. Among 1,971 students from primary and secondary schools around Nairobi (aged 8–19), 22.1 % reported a lifetime history of a psychotic experience, and 16.3 % reported this unrelated to sleep or drugs. Psychotic experiences were more common in males compared to females. LCA resulted in a three-class model comprised of a normative class (83.3 %), a predominately hallucinatory class (Type 1 psychosis: 9.6 %), and a pan-psychotic class (Type 2 psychosis: 7.2 %). These results indicate that PLEs are prevalent in children and adolescents, and the distributions of symptom clusters are similar to that found in adulthood. The relationship of specific PLEs to the future development of psychotic disorder, functional impairment or distress will require further study. PMID:23065300

Classes of psychotic experiences in Kenyan children and adolescents.

PubMed

Mamah, Daniel; Owoso, Akinkunle; Mbwayo, Anne W; Mutiso, Victoria N; Muriungi, Susan K; Khasakhala, Lincoln I; Barch, Deanna M; Ndetei, David M

2013-06-01

Psychotic-like experiences (PLEs) have been observed worldwide in both adults and children outside the context of a clinical disorder. In the current study, we investigate the prevalence and patterns of PLEs among children and adolescents in Kenya. Among 1,971 students from primary and secondary schools around Nairobi (aged 8-19), 22.1 % reported a lifetime history of a psychotic experience, and 16.3 % reported this unrelated to sleep or drugs. Psychotic experiences were more common in males compared to females. LCA resulted in a three-class model comprised of a normative class (83.3 %), a predominately hallucinatory class (Type 1 psychosis: 9.6 %), and a pan-psychotic class (Type 2 psychosis: 7.2 %). These results indicate that PLEs are prevalent in children and adolescents, and the distributions of symptom clusters are similar to that found in adulthood. The relationship of specific PLEs to the future development of psychotic disorder, functional impairment or distress will require further study.

Peripheral formalin injection induces unique spinal cord microglial phenotypic changes

PubMed Central

Fu, Kai-Yuan; Tan, Yong-Hui; Sung, Backil; Mao, Jianren

2014-01-01

Microglia are resident immune cells of brain and activated by peripheral tissue injury. In the present study, we investigated the possible induction of several microglial surface immunomolecules in the spinal cord, including leukocyte common antigen (LCA/CD45), MHC class I antigen, MHC class II antigen, Fc receptor, and CD11c following formalin injection into the rat’s hind paw. CD45 and MHC class I were upregulated in the activated microglia, which was evident on day 3 with the peak expression on day 7 following peripheral formalin injection. There was a very low basal expression of MHC class II, CD11c, and the Fc receptor, which did not change after the formalin injection. These results, for the first time, indicate that peripheral formalin injection can induce phenotypic changes of microglia with distinct upregulation of CD45 and MHC class I antigen. The data suggest that phenotypic changes of the activated microglia may be a unique pattern of central changes following peripheral tissue injury. PMID:19015000

Prevalence and co-occurrence of addictive behaviors among former alternative high school youth: A longitudinal follow-up study

PubMed Central

Sussman, Steve; Pokhrel, Pallav; Sun, Ping; Rohrbach, Louise A.; Spruijt-Metz, Donna

2015-01-01

Background and Aims Recent work has studied addictions using a matrix measure, which taps multiple addictions through single responses for each type. This is the first longitudinal study using a matrix measure. Methods We investigated the use of this approach among former alternative high school youth (average age = 19.8 years at baseline; longitudinal n = 538) at risk for addictions. Lifetime and last 30-day prevalence of one or more of 11 addictions reviewed in other work was the primary focus (i.e., cigarettes, alcohol, hard drugs, shopping, gambling, Internet, love, sex, eating, work, and exercise). These were examined at two time-points one year apart. Latent class and latent transition analyses (LCA and LTA) were conducted in Mplus. Results Prevalence rates were stable across the two time-points. As in the cross-sectional baseline analysis, the 2-class model (addiction class, non-addiction class) fit the data better at follow-up than models with more classes. Item-response or conditional probabilities for each addiction type did not differ between time-points. As a result, the LTA model utilized constrained the conditional probabilities to be equal across the two time-points. In the addiction class, larger conditional probabilities (i.e., 0.40−0.49) were found for love, sex, exercise, and work addictions; medium conditional probabilities (i.e., 0.17−0.27) were found for cigarette, alcohol, other drugs, eating, Internet and shopping addiction; and a small conditional probability (0.06) was found for gambling. Discussion and Conclusions Persons in an addiction class tend to remain in this addiction class over a one-year period. PMID:26551909

Patterns of separation anxiety symptoms amongst pregnant women in conflict-affected Timor-Leste: Associations with traumatic loss, family conflict, and intimate partner violence.

PubMed

Silove, D M; Tay, A K; Tol, W A; Tam, N; Dos Reis, N; da Costa, Z; Soares, C; Rees, S

2016-11-15

Adult separation anxiety (ASA) symptoms are prevalent amongst young women in low and middle-income countries and symptoms may be common in pregnancy. No studies have focused on defining distinctive patterns of ASA symptoms amongst pregnant women in these settings or possible associations with trauma exposure and ongoing stressors. In a consecutive sample of 1672 women attending antenatal clinics in Dili, Timor-Leste (96% response), we assessed traumatic events of conflict, ongoing adversity, intimate partner violence (IPV), ASA, post-traumatic stress disorder (PTSD) and severe psychological distress. Latent Class Analysis was used to identify classes of women based on their distinctive profiles of ASA symptoms, comparisons then being made with key covariates including trauma domains of conflict, intimate partner violence (IPV) and ongoing stressors. LCA yielded three classes, comprising a core ASA (4%), a limited ASA (25%) and a low symptom class (61%). The core ASA class reported exposure to multiple traumatic losses and IPV and showed a pattern of comorbidity with PTSD; the limited ASA class predominantly reported exposure to ongoing stressors and was comorbid with severe psychological distress; the low symptom class reported relatively low levels of exposure to trauma and stressors. The study is cross-sectional, cautioning against inferring causal inferences. The core ASA group may be in need of immediate intervention given the high rate of exposure to IPV amongst this class. A larger number of women experiencing a limited array of non-specific ASA symptoms may need assistance to address the immediate stressors of pregnancy. Copyright © 2016 Elsevier B.V. All rights reserved.

Life cycle energy and greenhouse gas emission effects of biodiesel in the United States with induced land use change impacts.

PubMed

Chen, Rui; Qin, Zhangcai; Han, Jeongwoo; Wang, Michael; Taheripour, Farzad; Tyner, Wallace; O'Connor, Don; Duffield, James

2018-03-01

This study conducted the updated simulations to depict a life cycle analysis (LCA) of the biodiesel production from soybeans and other feedstocks in the U.S. It addressed in details the interaction between LCA and induced land use change (ILUC) for biodiesel. Relative to the conventional petroleum diesel, soy biodiesel could achieve 76% reduction in GHG emissions without considering ILUC, or 66-72% reduction in overall GHG emissions when various ILUC cases were considered. Soy biodiesel's fossil fuel consumption rate was also 80% lower than its petroleum counterpart. Furthermore, this study examined the cause and the implication of each key parameter affecting biodiesel LCA results using a sensitivity analysis, which identified the hot spots for fossil fuel consumption and GHG emissions of biodiesel so that future efforts can be made accordingly. Finally, biodiesel produced from other feedstocks (canola oil and tallow) were also investigated to contrast with soy biodiesel and petroleum diesel. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Refinements in modeling the passive properties of laryngeal soft tissue.

PubMed

Hunter, Eric J; Titze, Ingo R

2007-07-01

The nonlinear viscoelastic passive properties of three canine intrinsic laryngeal muscles, the lateral cricoarytenoid (LCA), the posterior cricoarytenoid (PCA), and the interarytenoid (IA), were fit to the parameters of a modified Kelvin model. These properties were compared with those of the thyroarytenoid (TA) and cricothyroid (CT) muscles, as well as previously unpublished viscoelastic characteristics of the human vocal ligament. Passive parameters of the modified Kelvin model were summarized for the vocal ligament, mucosa, and all five laryngeal muscles. Results suggest that the LCA, PCA, and IA muscles are functionally different from the TA and CT muscles in their load-bearing capacity. Furthermore, the LCA, PCA, and IA have a much larger stress-strain hysteresis effect than has been previously reported for the TA and CT or the vocal ligament. The variation in this effect suggests that the connective tissue within the TA and CT muscles is somehow similar to the vocal ligament but different from the LCA, PCA, or IA muscles. Further demonstrating the potential significance of grouping tissues in the laryngeal system by functional groups in the laryngeal system was the unique finding that, over their working elongation range, the LCA and PCA were nearly as exponentially stiff as the vocal ligament. This paper was written in conjunction with an online technical report (http://www.ncvs.org/ncvs/library/tech) in which comprehensive muscle data and sensitivity analysis, as well as downloadable data files and computer scripts, are made available.

Patient factors and quality of life outcomes differ among four subgroups of oncology patients based on symptom occurrence.

PubMed

Astrup, Guro Lindviksmoen; Hofsø, Kristin; Bjordal, Kristin; Guren, Marianne Grønlie; Vistad, Ingvild; Cooper, Bruce; Miaskowski, Christine; Rustøen, Tone

2017-03-01

Reviews of the literature on symptoms in oncology patients undergoing curative treatment, as well as patients receiving palliative care, suggest that they experience multiple, co-occurring symptoms and side effects. The purposes of this study were to determine if subgroups of oncology patients could be identified based on symptom occurrence rates and if these subgroups differed on a number of demographic and clinical characteristics, as well as on quality of life (QoL) outcomes. Latent class analysis (LCA) was used to identify subgroups (i.e. latent classes) of patients with distinct symptom experiences based on the occurrence rates for the 13 most common symptoms from the Memorial Symptom Assessment Scale. In total, 534 patients with breast, head and neck, colorectal, or ovarian cancer participated. Four latent classes of patients were identified based on probability of symptom occurrence: all low class [i.e. low probability for all symptoms (n = 152)], all high class (n = 149), high psychological class (n = 121), and low psychological class (n = 112). Patients in the all high class were significantly younger compared with patients in the all low class. Furthermore, compared to the other three classes, patients in the all high class had lower functional status and higher comorbidity scores, and reported poorer QoL scores. Patients in the high and low psychological classes had a moderate probability of reporting physical symptoms. Patients in the low psychological class reported a higher number of symptoms, a lower functional status, and poorer physical and total QoL scores. Distinct subgroups of oncology patients can be identified based on symptom occurrence rates. Patient characteristics that are associated with these subgroups can be used to identify patients who are at greater risk for multiple co-occurring symptoms and diminished QoL, so that these patients can be offered appropriate symptom management interventions.

Mouse Models as Tools to Identify Genetic Pathways for Retinal Degeneration, as Exemplified by Leber's Congenital Amaurosis.

PubMed

Chang, Bo

2016-01-01

Leber's congenital amaurosis (LCA) is an inherited retinal degenerative disease characterized by severe loss of vision in the first year of life. In addition to early vision loss, a variety of other eye-related abnormalities including roving eye movements, deep-set eyes, and sensitivity to bright light also occur with this disease. Many animal models of LCA are available and the study them has led to a better understanding of the pathology of the disease, and has led to the development of therapeutic strategies aimed at curing or slowing down LCA. Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human LCA. Such mice provide reproducible, experimental systems for elucidating pathways of normal development, function, designing strategies and testing compounds for translational research and gene-based therapies aimed at delaying the diseases progression. In this chapter, I describe tools used in the discovery and evaluation of mouse models of LCA including a Phoenix Image-Guided Optical Coherence Tomography (OCT) and a Diagnosys Espion Visual Electrophysiology System. Three mouse models are described, the rd3 mouse model for LCA12 and LCA1, the rd12 mouse model for LCA2, and the rd16 mouse model for LCA10.

STREAMLINED LIFE CYCLE ASSESSMENT: A FINAL REPORT FROM THE SETAC-NORTH AMERICA STREAMLINED LCA WORKGROUP

EPA Science Inventory

The original goal of the Streamlined LCA workgroup was to define and document a process for a shortened form of LCA. At the time, because of the large amount of data needed to do a cradle-to-grave evaluation, it was believed that in addition to such a "full" LCA approach there w...

Patterns of Alcohol Use Among Canadian Military Personnel and Their Associations With Health and Well-Being.

PubMed

Richer, Isabelle; Lee, Jennifer E C; Born, Jennifer

2016-04-07

Heavy drinking increases the risk of injury, adverse physical and mental health outcomes, and loss of productivity. Nonetheless, patterns of alcohol use and related symptomatology among military personnel remain poorly understood. A latent class analysis (LCA) was used to explore the presence of subgroups of alcohol users among Canadian Armed Forces (CAF) Regular Forces members. Correlates of empirically derived subgroups were further explored. Analyses were performed on a subsample of alcohol users who participated in a 2008/09 cross-sectional survey of a stratified random sample of currently serving CAF Regular Force members (N = 1980). Multinomial logistic regression models were conducted to verify physical and mental health differences across subgroups of alcohol users. All analyses were adjusted for complex survey design. A 4-class solution was considered the best fit for the data. Subgroups were labeled as follows: Class 1 - Infrequent drinkers (27.2%); Class 2 - Moderate drinkers (41.5%); Class 3 - Regular binge drinkers with minimal problems (14.8%); and Class 4 - Problem drinkers (16.6%). Significant differences by age, sex, marital status, element, rank, recent serious injuries, chronic conditions, psychological distress, posttraumatic stress disorder, and depression symptoms were found across the subgroups. Problem drinkers demonstrated the most degraded physical and mental health. Findings highlight the heterogeneity of alcohol users and heavy drinkers among CAF members and the need for tailored interventions addressing high-risk alcohol use. Results have the potential to inform prevention strategies and screening efforts. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Chemical Chaperone TUDCA Preserves Cone Photoreceptors in a Mouse Model of Leber Congenital Amaurosis

PubMed Central

Zhang, Tao; Baehr, Wolfgang; Fu, Yingbin

2012-01-01

Purpose. Mutations in either retinoid isomerase (RPE65) or lecithin-retinol acyltransferase (LRAT) lead to Leber congenital amaurosis (LCA). By using the Lrat–/– mouse model, previous studies have shown that the rapid cone degeneration in LCA was caused by endoplasmic reticulum (ER) stress induced by S-opsin aggregation. The purpose of this study is to examine the efficacy of an ER chemical chaperone, tauroursodeoxycholic acid (TUDCA), in preserving cones in the Lrat–/– model. Methods. Lrat–/– mice were systemically administered with TUDCA and vehicle (0.15 M NaHCO3) every 3 days from P9 to P28. Cone cell survival was determined by counting cone cells on flat-mounted retinas. The expression and subcellular localization of cone-specific proteins were analyzed by western blotting and immunohistochemistry, respectively. Results. TUDCA treatment reduced ER stress and apoptosis in Lrat–/– retina. It significantly slowed down cone degeneration in Lrat–/– mice, resulting in a ∼3-fold increase in cone density in the ventral and central retina as compared with the vehicle-treated mice at P28. Furthermore, TUDCA promoted the degradation of cone membrane–associated proteins by enhancing the ER-associated protein degradation pathway. Conclusions. Systemic injection of TUDCA is effective in reducing ER stress, preventing apoptosis, and preserving cones in Lrat–/– mice. TUDCA has the potential to lead to the development of a new class of therapeutic drugs for treating LCA. PMID:22531707

Can environmental improvement change the population distribution of walking?

PubMed

Panter, Jenna; Ogilvie, David

2017-06-01

Few studies have explored the impact of environmental change on walking using controlled comparisons. Even fewer have examined whose behaviour changes and how. In a natural experimental study of new walking and cycling infrastructure, we explored changes in walking, identified groups who changed in similar ways and assessed whether exposure to the infrastructure was associated with trajectories of walking. 1257 adults completed annual surveys assessing walking, sociodemographic and health characteristics and use of the infrastructure (2010-2012). Residential proximity to the new routes was assessed objectively. We used latent growth curve models to assess change in total walking, walking for recreation and for transport, used simple descriptive analysis and latent class analysis (LCA) to identify groups who changed in similar ways and examined factors associated with group membership using multinomial regression. LCA identified five trajectories, characterised by consistently low levels; consistently high levels; decreases; short-lived increases; and sustained increases. Those with lower levels of education and lower incomes were more likely to show both short-lived and sustained increases in walking for transport. However, those with lower levels of education were less likely to take up walking. Proximity to the intervention was associated with both uptake of and short-lived increases in walking for transport. Environmental improvement encouraged the less active to take up walking for transport, as well as encouraging those who were already active to walk more. Further research should disentangle the role of socioeconomic characteristics in determining use of new environments and changes in walking. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Greenhouse Gas Emissions of Beef Cattle Production in the Southern Great Plains

NASA Astrophysics Data System (ADS)

Kannan, N.; Niraula, R.; Saleh, A.; Osei, E.; Cole, A.; Todd, R.; Waldrip, H.; Aljoe, H.

2017-12-01

A five-year USDA-funded study titled "Resilience and vulnerability of beef cattle production in the Southern Great Plains under changing climate, land use, and markets" was initiated as a multi-institutional collaboration involving Texas Institute for Applied Environmental Research (TIAER)—Tarleton State University, United States Department of Agriculture (USDA)—Agricultural Research Service (ARS) in El Reno, Oklahoma, USDA—ARS in Bushland, Texas, Kansas State University, Oklahoma State University, University of Oklahoma, and the Noble Research Institute in Ardmore, Oklahoma. The project goal is to safeguard and promote regional beef production while mitigating its environmental footprint. Conducting a full Life Cycle Analysis (LCA) is one of the major objectives of the study, in addition to field experiments, extension, outreach, and education. Estimation of all the resource use and greenhouse gas emissions are parts of the LCA. A computer model titled Animal Production Life Cycle Analysis Tool (APLCAT) is developed and applied to conduct the LCA on beef cattle production in the study region. The model estimates water use, energy requirements, and emissions of enteric methane, manure methane, nitrous oxide, and carbon dioxide. Also included in the LCA analysis are land-atmospheric exchanges of methane, nitrous oxide, carbon dioxide and the global warming potential. Our study is focused on the cow-calf and stocker phases of beef cattle production. The animal production system in the study region is predominantly forage based with protein and energy supplements when needed. Spring calving typical to the study region. In the cow-calf phase animals typically graze native prairie although introduced pasture grazing is also prevalent. Stockers use winter pasture as the major feed. The results of greenhouse gas emissions summarized per kg of hot carcass weight or animal fed will be presented.

Ignoring correlation in uncertainty and sensitivity analysis in life cycle assessment: what is the risk?

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

Groen, E.A., E-mail: Evelyne.Groen@gmail.com; Heijungs, R.; Leiden University, Einsteinweg 2, Leiden 2333 CC

Life cycle assessment (LCA) is an established tool to quantify the environmental impact of a product. A good assessment of uncertainty is important for making well-informed decisions in comparative LCA, as well as for correctly prioritising data collection efforts. Under- or overestimation of output uncertainty (e.g. output variance) will lead to incorrect decisions in such matters. The presence of correlations between input parameters during uncertainty propagation, can increase or decrease the the output variance. However, most LCA studies that include uncertainty analysis, ignore correlations between input parameters during uncertainty propagation, which may lead to incorrect conclusions. Two approaches to include correlationsmore » between input parameters during uncertainty propagation and global sensitivity analysis were studied: an analytical approach and a sampling approach. The use of both approaches is illustrated for an artificial case study of electricity production. Results demonstrate that both approaches yield approximately the same output variance and sensitivity indices for this specific case study. Furthermore, we demonstrate that the analytical approach can be used to quantify the risk of ignoring correlations between input parameters during uncertainty propagation in LCA. We demonstrate that: (1) we can predict if including correlations among input parameters in uncertainty propagation will increase or decrease output variance; (2) we can quantify the risk of ignoring correlations on the output variance and the global sensitivity indices. Moreover, this procedure requires only little data. - Highlights: • Ignoring correlation leads to under- or overestimation of the output variance. • We demonstrated that the risk of ignoring correlation can be quantified. • The procedure proposed is generally applicable in life cycle assessment. • In some cases, ignoring correlation has a minimal effect on decision-making tools.« less

Assessing food security in water scarce regions by Life Cycle Analysis: a case study in the Gaza strip

NASA Astrophysics Data System (ADS)

Recanati, Francesca; Castelletti, Andrea; Melià, Paco; Dotelli, Giovanni

2013-04-01

Food security is a major issue in Palestine for both political and physical reasons, with direct effects on the local population living conditions: the nutritional level of people in Gaza is classified by FAO as "insecure". As most of the protein supply comes from irrigated agricultural production and aquaculture, freshwater availability is a limiting factor to food security, and the primary reason for frequent conflicts among food production processes (e.g. aquaculture, land livestock or different types of crops). In this study we use Life Cycle Analysis to assess the environmental impacts associated to all the stages of water-based protein production (from agriculture and aquaculture) in the Gaza strip under different agricultural scenarios and hydroclimatic variability. As reported in several recent studies, LCA seems to be an appropriate methodology to analyze agricultural systems and assess associated food security in different socio-economic contexts. However, we argue that the inherently linear and static nature of LCA might prove inadequate to tackle with the complex interaction between water cycle variability and the food production system in water-scarce regions of underdeveloped countries. Lack of sufficient and reliable data to characterize the water cycle is a further source of uncertainty affecting the robustness of the analysis. We investigate pros and cons of LCA and LCA-based option planning in an average size farm in Gaza strip, where farming and aquaculture are family-based and integrated by reuse of fish breeding water for irrigation. Different technological solutions (drip irrigation system, greenhouses etc.) are evaluated to improve protein supply and reduce the pressure on freshwater, particularly during droughts. But this use of technology represent also a contribution in increasing sustainability in agricultural processes, and therefore in economy, of Gaza Strip (reduction in chemical fertilizers and pesticides etc.).

Practical LCA for short shelf life products

NASA Astrophysics Data System (ADS)

Laurin, Lise; Goedkoop, Mark; Norris, Greg

2005-11-01

Manufacturers in many of today's industries are faced with product shelf life counted in months. Traditionally, this has made it very difficult to make a life cycle assessment (LCA) of a product, since the product would be obsolete by the time the LCA was completed. A new concept in LCA that allows specialists in things other than LCA to rapidly create both a model and generate "what-if" scenarios will allow even manufacturers of short shelf life products take advantage of the benefits of LCA. These industry-specific "wizards" are built around a manufacturing process and can be rapidly updated or customized to a particular manufacturer or process type. Results can be used internally for decision-making and can also enable manufacturers submit information for environmentally preferable purchasing, eco-labels, etc.

An innovative implementation of LCA within the EIA procedure: Lessons learned from two Wastewater Treatment Plant case studies

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

Larrey-Lassalle, Pyrène, E-mail: pyrene.larrey-lassalle@irstea.fr; LGEI, Ecole des mines d'Alès, 6 avenue de Clavières, 30319 Alès Cedex; Catel, Laureline

Life Cycle Assessment (LCA) has been identified in the literature as a promising tool to increase the performance of environmental assessments at different steps in the Environmental Impact Assessment (EIA) procedure. However, few publications have proposed a methodology for an extensive integration, and none have compared the results with existing EIA conclusions without LCA. This paper proposes a comprehensive operational methodology for implementing an LCA within an EIA. Based on a literature review, we identified four EIA steps that could theoretically benefit from LCA implementation, i.e., (a) the environmental comparison of alternatives, (b) the identification of key impacts, (c) themore » impact assessment, and (d) the impact of mitigation measures. For each of these steps, an LCA was implemented with specific goal and scope definitions that resulted in a specific set of indicators. This approach has been implemented in two contrasting Wastewater Treatment Plant (WWTP) projects and compared to existing EIA studies. The results showed that the two procedures, i.e., EIAs with or without inputs from LCA, led to different conclusions. The environmental assessments of alternatives and mitigation measures were not carried out in the original studies and showed that other less polluting technologies could have been chosen. Regarding the scoping step, the selected environmental concerns were essentially different. Global impacts such as climate change or natural resource depletion were not taken into account in the original EIA studies. Impacts other than those occurring on the project site (off-site impacts) were not assessed, either. All these impacts can be significant compared to those initially considered. On the other hand, unlike current LCA applications, EIAs usually address natural and technological risks and neighbourhood disturbances such as noises or odours, which are very important for the public acceptability of projects. Regarding the impact assessment, even if the conclusions of the EIAs with or without LCA were partially common for local on-site impacts, LCA gives crucial additional information on global and off-site impacts and highlights the processes responsible for them. Finally, for all EIA steps investigated, interest in LCA was demonstrated for both WWTP case studies. The feasibility in terms of skills, time and cost of such implementation has also been assessed. - Highlights: • An innovative methodology for a first-stage implementation of LCA in EIA is proposed. • Its applicability is demonstrated on two Wastewater Treatment Plant case studies. • The conclusions for the four EIA steps investigated differ with or without LCA. • LCA provides valuable additional information on 1) global and 2) off-site impacts. • LCA identifies pollution transfers towards a life cycle perspective.« less

Genetic and phenotypic overlap of specific obsessive-compulsive and attention-deficit/hyperactive subtypes with Tourette syndrome.

PubMed

Hirschtritt, M E; Darrow, S M; Illmann, C; Osiecki, L; Grados, M; Sandor, P; Dion, Y; King, R A; Pauls, D; Budman, C L; Cath, D C; Greenberg, E; Lyon, G J; Yu, D; McGrath, L M; McMahon, W M; Lee, P C; Delucchi, K L; Scharf, J M; Mathews, C A

2018-01-01

The unique phenotypic and genetic aspects of obsessive-compulsive (OCD) and attention-deficit/hyperactivity disorder (ADHD) among individuals with Tourette syndrome (TS) are not well characterized. Here, we examine symptom patterns and heritability of OCD and ADHD in TS families. OCD and ADHD symptom patterns were examined in TS patients and their family members (N = 3494) using exploratory factor analyses (EFA) for OCD and ADHD symptoms separately, followed by latent class analyses (LCA) of the resulting OCD and ADHD factor sum scores jointly; heritability and clinical relevance of the resulting factors and classes were assessed. EFA yielded a 2-factor model for ADHD and an 8-factor model for OCD. Both ADHD factors (inattentive and hyperactive/impulsive symptoms) were genetically related to TS, ADHD, and OCD. The doubts, contamination, need for sameness, and superstitions factors were genetically related to OCD, but not ADHD or TS; symmetry/exactness and fear-of-harm were associated with TS and OCD while hoarding was associated with ADHD and OCD. In contrast, aggressive urges were genetically associated with TS, OCD, and ADHD. LCA revealed a three-class solution: few OCD/ADHD symptoms (LC1), OCD & ADHD symptoms (LC2), and symmetry/exactness, hoarding, and ADHD symptoms (LC3). LC2 had the highest psychiatric comorbidity rates (⩾50% for all disorders). Symmetry/exactness, aggressive urges, fear-of-harm, and hoarding show complex genetic relationships with TS, OCD, and ADHD, and, rather than being specific subtypes of OCD, transcend traditional diagnostic boundaries, perhaps representing an underlying vulnerability (e.g. failure of top-down cognitive control) common to all three disorders.

Life cycle assessment of first-generation biofuels using a nitrogen crop model.

PubMed

Gallejones, P; Pardo, G; Aizpurua, A; del Prado, A

2015-02-01

This paper presents an alternative approach to assess the impacts of biofuel production using a method integrating the simulated values of a new semi-empirical model at the crop production stage within a life cycle assessment (LCA). This new approach enabled us to capture some of the effects that climatic conditions and crop management have on soil nitrous oxide (N₂O) emissions, crop yields and other nitrogen (N) losses. This analysis considered the whole system to produce 1 MJ of biofuel (bioethanol from wheat and biodiesel from rapeseed). Non-renewable energy use, global warming potential (GWP), acidification, eutrophication and land competition are considered as potential environmental impacts. Different co-products were handled by system expansion. The aim of this study was (i) to evaluate the variability due to site-specific conditions of climate and fertiliser management of the LCA of two different products: biodiesel from rapeseed and bioethanol from wheat produced in the Basque Country (Northern Spain), and (ii) to improve the estimations of the LCA impacts due to N losses (N₂O, NO₃, NH₃), normally estimated with unspecific emission factors (EFs), that contribute to the impact categories analysed in the LCA of biofuels at local scale. Using biodiesel and bioethanol derived from rapeseed and wheat instead of conventional diesel and gasoline, respectively, would reduce non-renewable energy dependence (-55%) and GWP (-40%), on average, but would increase eutrophication (42 times more potential). An uncertainty analysis for GWP impact showed that the variability associated with the prediction of the major contributor to global warming potential (soil N₂O) can significantly affect the results from the LCA. Therefore the use of a model to account for local factors will improve the precision of the assessment and reduce the uncertainty associated with the convenience of the use of biofuels. Copyright © 2014 Elsevier B.V. All rights reserved.

LCA in space - current status and future development

NASA Astrophysics Data System (ADS)

Ko, Nathanael; Betten, Thomas; Schestak, Isabel; Gantner, Johannes

2018-06-01

This paper represents the first stage of extending the scope of LCA to space and is intended as a discussion starter. Based on the assumption, that the future and outlast of humanity lies within the exploration and colonisation of space, the LCA methodology as of today, is discussed with regards to its capabilities to cover the impact of human activities in space. Based on this assessment, ideas whether and how LCA can be extended are outlined. Initially, an understanding of additional environmental impacts which occur in space compared to Earth is built up by the means of literature research. The state of the art of space regulations and availability of LCAs in space and for astronautics is clarified as well. Further literature research was conducted on the LCA subtopic of regionalization. Based on this and assumptions regarding future space travel, the suitability of LCA as an assessment method is validated. Afterwards, different potential development phases of LCA towards its applicability in space are defined. For activities in space, the regarded environmental impacts have to be expanded (e.g. space debris, extra-terrestrial life toxicity, etc.). Space regulations, if in place, cover only impacts of space activities on Earth so far. LCAs for space activities are not widespread yet. One reason for this is that the state of the art LCA methodology has not been expanded and existing regionalisation approaches are not easily transferable to space. Critical issues are faced in all phases of an LCA and include widening of boundaries, definition of space regions, finding suitable reference units and ethical problems. As a result, four LCA development phases are suggested: Earth-bound, solar system-bound, transition phase and intergalactic. Each phase involves different activities and goals, which result in different system boundaries and impact categories and widen the scope of LCA subsequently. It is a long way for humanity to populate space and so, it is for enabling LCA to assess these activities. The methodology of LCA is flexible and capable to make this adaptation. This paper can be seen as a starting point of a discussion opening up many questions. Some of these questions can only be answered in the future with more certainty about the development of space colonialization.

Flow list and test results

EPA Pesticide Factsheets

These data accompany the manuscript 'Critical Review of Elementary Flows in LCA Data'. Each file presents a subgroup of the elementary flows (data used for analysis) and all the analysis results. Files are separated by flow types. The 'Element or Compound' types contained over 115,000 flows and was broken into three files (a, b,and c). A guide to the file contents and explanation of flow types are provided in the 'CriticalReviewofElementaryFlows_Data_Guide' file.This dataset is associated with the following publication:Edelen, A., W. Ingwersen, C. Rodriguez, R. Alvarenga, A.R. de Almeida, and G. Wernet. Critical Review of Elementary Flows in LCA data. INTERNATIONAL JOURNAL OF LIFE CYCLE ASSESSMENT. Ecomed Verlagsgesellschaft AG, Landsberg, GERMANY,

Comparative life cycle assessments: The case of paper and digital media

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

Bull, Justin G., E-mail: jgbull@gmail.com; Kozak, Robert A., E-mail: rob.kozak@ubc.ca

The consumption of the written word is changing, as media transitions from paper products to digital alternatives. We reviewed the life cycle assessment (LCA) research literature that compared the environmental footprint of digital and paper media. To validate the role of context in influencing LCA results, we assessed LCAs that did not compare paper and print, but focused on a product or component that is part of the Information and Communication Technology (ICT) sector. Using a framework that identifies problems in LCA conduct, we assessed whether the comparative LCAs were accurate expressions of the environmental footprints of paper and print.more » We hypothesized that the differences between the product systems that produce paper and digital media weaken LCA's ability to compare environmental footprints. We also hypothesized that the characteristics of ICT as an industrial sector weaken LCA as an environmental assessment methodology. We found that existing comparative LCAs offered problematic comparisons of paper and digital media for two reasons — the stark material differences between ICT products and paper products, and the unique characteristics of the ICT sector. We suggested that the context of the ICT sector, best captured by the concept of “Moore's Law”, will continuously impede the ability of the LCA methodology to measure ICT products. -- Highlights: • We review the LCA research that compares paper and digital media. • We contrast the comparative LCAs with LCAs that examine only digital products. • Stark differences between paper and digital media weakens LCA findings. • Digital products in general challenge the LCA method's reliability. • Continuous innovation and global nature of digital products impedes LCA methodology.« less

Investor Outlook: Focus on Upcoming LCA2 Gene Therapy Phase III Results.

PubMed

Schimmer, Joshua; Breazzano, Steven

2015-09-01

Investor interest in gene therapy has increased substantially over the past few years, and the next major catalyst for the field is likely to be Spark Therapeutics's phase III trial for the treatment of visual impairment caused by RPE65 gene mutations (often referred to as Leber congenital amaurosis type 2, or LCA2, but may include other retinal disorders). Analysis of the approach from the basic genetics, underlying visual mechanisms, clinical data, and commercialization considerations helps frame investor expectations and the potential implications for the broader field.

International LCA

EPA Science Inventory

To provide global guidance on the establishment and maintenance of LCA databases, as the basis for improved dataset exchangeability and interlinkages of databases worldwide. Increase the credibility of existing LCA data, the generation of more data and their overall accessibilit...

Life cycle assessments of urban water systems: a comparative analysis of selected peer-reviewed literature.

PubMed

Loubet, Philippe; Roux, Philippe; Loiseau, Eleonore; Bellon-Maurel, Veronique

2014-12-15

Water is a growing concern in cities, and its sustainable management is very complex. Life cycle assessment (LCA) has been increasingly used to assess the environmental impacts of water technologies during the last 20 years. This review aims at compiling all LCA papers related to water technologies, out of which 18 LCA studies deals with whole urban water systems (UWS). A focus is carried out on these 18 case studies which are analyzed according to criteria derived from the four phases of LCA international standards. The results show that whereas the case studies share a common goal, i.e., providing quantitative information to policy makers on the environmental impacts of urban water systems and their forecasting scenarios, they are based on different scopes, resulting in the selection of different functional units and system boundaries. A quantitative comparison of life cycle inventory and life cycle impact assessment data is provided, and the results are discussed. It shows the superiority of information offered by multi-criteria approaches for decision making compared to that derived from mono-criterion. From this review, recommendations on the way to conduct the environmental assessment of urban water systems are given, e.g., the need to provide consistent mass balances in terms of emissions and water flows. Remaining challenges for urban water system LCAs are identified, such as a better consideration of water users and resources and the inclusion of recent LCA developments (territorial approaches and water-related impacts). Copyright © 2014 Elsevier Ltd. All rights reserved.

Choice of mineral fertilizer substitution principle strongly influences LCA environmental benefits of nutrient cycling in the agri-food system.

PubMed

Hanserud, Ola Stedje; Cherubini, Francesco; Øgaard, Anne Falk; Müller, Daniel B; Brattebø, Helge

2018-02-15

Increased nutrient cycling in the agri-food system is a way to achieve a healthier nutrient stewardship and more sustainable food production. In life cycle assessment (LCA) studies, use of recycled fertilizer products is often credited by the substitution method, which subtracts the environmental burdens associated with avoided production of mineral fertilizer from the system under study. The environmental benefits from avoided fertilizer production can make an important contribution to the results, but different calculation principles and often implicit assumptions are used to estimate the amount of avoided mineral fertilizer. This may hinder comparisons between studies. The present study therefore examines how the choice of substitution principles influences LCA results. Three different substitution principles, called one-to-one, maintenance, and adjusted maintenance, are identified, and we test the importance of these in a case study on cattle slurry management. We show that the inventory of avoided mineral fertilizer varies greatly when the different principles are applied, with strong influences on two-thirds of LCA impact categories. With the one-to-one principle, there is a risk of systematically over-estimating the environmental benefits from nutrient cycling. In a sensitivity analysis we show that the difference between the principles is closely related to the application rate and levels of residual nutrients in the soil. We recommend that LCA practitioners first and foremost state and justify the substitution method they use, in order to increase transparency and comparability with other studies. Copyright © 2017 Elsevier B.V. All rights reserved.

Life Cycle Assessment (ISO 14040) implementation in foods of animal and plant origin: review.

PubMed

Arvanitoyannis, Ioannis S; Kotsanopoulos, Konstantinos V; Veikou, Agapi

2014-01-01

The importance of environmental protection has been recently upgraded due to the continuously increasing environmental pollution load. Life Cycle Assessment (LCA), wellknown as ISO 14040, has been repeatedly shown to be a useful and powerful tool for assessing the environmental performance of industrial processes, both in the European and American continents as well as in many Asian countries (such as Japan and China). To the best of our knowledge, almost no information is provided in relation to LCA implementation in Africa apart from an article related to Egypt. Although food industries are not considered to be among the most heavily polluting ones, for some like olive oil, wine, dairy, and meat processing, their impact on the environment is a heavy burden. The introduction of LCA aimed at identifying both inputs and outputs to find out which are the most detrimental to the environment in terms of water/energy consumption and solid/liquid and gas releases. In this review, a thorough coverage of literature was made in an attempt to compare the implementation of LCA to a variety of products of both plant and animal origin. It was concluded that there is a high number of subsystems suggested for the same product, thereby, occasionally leading to confusion. An idea toward solving the problem is to proceed to some sort of standardization by means of several generic case studies of LCA implementation, similarly to what had happened in the case of Hazard Analysis and Critical Control Points (HACCP) implementation in the United States, Canada, Australia, United Kingdom, and other countries.

Life cycle assessment of integrated waste management systems for alternative legacy scenarios of the London Olympic Park

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

Parkes, Olga, E-mail: o.parkes@ucl.ac.uk; Lettieri, Paola, E-mail: p.lettieri@ucl.ac.uk; Bogle, I. David L.

Highlights: • Application of LCA in planning integrated waste management systems. • Environmental valuation of 3 legacy scenarios for the Olympic Park. • Hot-spot analysis highlights the importance of energy and materials recovery. • Most environmental savings are achieved through materials recycling. • Sensitivity analysis shows importance of waste composition and recycling rates. - Abstract: This paper presents the results of the life cycle assessment (LCA) of 10 integrated waste management systems (IWMSs) for 3 potential post-event site design scenarios of the London Olympic Park. The aim of the LCA study is to evaluate direct and indirect emissions resulting frommore » various treatment options of municipal solid waste (MSW) annually generated on site together with avoided emissions resulting from energy, materials and nutrients recovery. IWMSs are modelled using GaBi v6.0 Product Sustainability software and results are presented based on the CML (v.Nov-10) characterisation method. The results show that IWMSs with advanced thermal treatment (ATT) and incineration with energy recovery have the lowest Global Warming Potential (GWP) than IWMSs where landfill is the primary waste treatment process. This is due to higher direct emissions and lower avoided emissions from the landfill process compared to the emissions from the thermal treatment processes. LCA results demonstrate that significant environmental savings are achieved through substitution of virgin materials with recycled ones. The results of the sensitivity analysis carried out for IWMS 1 shows that increasing recycling rate by 5%, 10% and 15% compared to the baseline scenario can reduce GWP by 8%, 17% and 25% respectively. Sensitivity analysis also shows how changes in waste composition affect the overall result of the system. The outcomes of such assessments provide decision-makers with fundamental information regarding the environmental impacts of different waste treatment options necessary for sustainable waste management planning.« less

Illustrating anticipatory life cycle assessment for emerging photovoltaic technologies.

PubMed

Wender, Ben A; Foley, Rider W; Prado-Lopez, Valentina; Ravikumar, Dwarakanath; Eisenberg, Daniel A; Hottle, Troy A; Sadowski, Jathan; Flanagan, William P; Fisher, Angela; Laurin, Lise; Bates, Matthew E; Linkov, Igor; Seager, Thomas P; Fraser, Matthew P; Guston, David H

2014-09-16

Current research policy and strategy documents recommend applying life cycle assessment (LCA) early in research and development (R&D) to guide emerging technologies toward decreased environmental burden. However, existing LCA practices are ill-suited to support these recommendations. Barriers related to data availability, rapid technology change, and isolation of environmental from technical research inhibit application of LCA to developing technologies. Overcoming these challenges requires methodological advances that help identify environmental opportunities prior to large R&D investments. Such an anticipatory approach to LCA requires synthesis of social, environmental, and technical knowledge beyond the capabilities of current practices. This paper introduces a novel framework for anticipatory LCA that incorporates technology forecasting, risk research, social engagement, and comparative impact assessment, then applies this framework to photovoltaic (PV) technologies. These examples illustrate the potential for anticipatory LCA to prioritize research questions and help guide environmentally responsible innovation of emerging technologies.

Direct and indirect generation of waste in the Spanish paper industry.

PubMed

Ruiz Peñalver, Soraya María; Rodríguez Molina, Mercedes; Camacho Ballesta, José Antonio

2014-01-01

The paper industry has a relatively high degree of reliance on suppliers when compared to other industries. Exploring the role of the paper industry in terms of consumption of intermediate inputs from other industries may help to understand how the production of paper does not only generate waste by itself but also affects the amount of waste generated by other industries. The product Life Cycle Assessment (LCA) is a useful analytical tool to examine and assess environmental impacts over the entire life cycle of a product "from cradle to grave" but it is costly and time intensive. In contrast, Economic Input Output Life Cycle Assessment Models (IO-LCA) that combine LCA with Input-Output analysis (IO) are more accurate and less expensive, as they employ publicly available data. This paper represents one of the first Spanish studies aimed at estimating the waste generated in the production of paper by applying IO-LCA. One of the major benefits is the derivation of the contribution of direct and indirect suppliers to the paper industry. The results obtained show that there was no direct relationship between the impact on output and the impact on waste generation exerted by the paper industry. The major contributors to waste generation were the mining industry and the forestry industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

NON-TRADITIONAL TOOLS FOR LCA AND SUSTAINABILITY

EPA Science Inventory

LCA practice focuses on impacts resulting from the release of chemicals into the environment, but consideration of "non-chemical impacts" is as important for LCA, particularly as it relates to sustainability. Methodologies and philosophies exist for addressing non-chemical impact...

Greenhouse gas emission mitigation relevant to changes in municipal solid waste management system.

PubMed

Pikoń, Krzysztof; Gaska, Krzysztof

2010-07-01

Standard methods for assessing the environmental impact of waste management systems are needed to underpin the development and implementation of sustainable waste management practice. Life cycle assessment (LCA) is a tool for comprehensively ensuring such assessment and covers all impacts associated with waste management. LCA is often called "from cradle to grave" analysis. This paper integrates information on the greenhouse gas (GHG) implications of various management options for some of the most common materials in municipal solid waste (MSW). Different waste treatment options for MSW were studied in a system analysis. Different combinations of recycling (cardboard, plastics, glass, metals), biological treatment (composting), and incineration as well as land-filling were studied. The index of environmental burden in the global warming impact category was calculated. The calculations are based on LCA methodology. All emissions taking place in the whole life cycle system were taken into account. The analysis included "own emissions," or emissions from the system at all stages of the life cycle, and "linked emissions," or emissions from other sources linked with the system in an indirect way. Avoided emissions caused by recycling and energy recovery were included in the analysis. Displaced emissions of GHGs originate from the substitution of energy or materials derived from waste for alternative sources. The complex analysis of the environmental impact of municipal waste management systems before and after application of changes in MSW systems according to European Union regulations is presented in this paper. The evaluation is made for MSW systems in Poland.

Influence of boron supplementation on performance, immunity and antioxidant status of lambs fed diets with or without adequate level of calcium

PubMed Central

Mondal, S.; Pattanaik, A. K.; Verma, A. K.

2017-01-01

Little is known about biological significance of effects of dietary Boron (B) and Calcium (Ca) interaction on health and production of farm animals. This is a preliminary investigation to evaluate the effects of B supplementation in lambs fed diets with (normal) or without adequate (low) levels of Ca. Twenty-four crossbred ram lambs were randomly distributed into four groups with six animals each in a 2x2 factorial design namely, normal-Ca diet (NCa) and low-Ca diet (LCa) fed without or with 40 ppm B (NCaB-40 and LCaB-40). The lambs were fed paddy straw and hybrid napier hay-based total mixed ration (60 roughage: 40 concentrate) during 180 days experimental period. Compared to control, the LCa diet lowered (P<0.01) average daily gain of lambs, but B-supplementation (LCaB-40) of the same nullified the effect. The lowered (P<0.05) total antioxidant activity and humoral immune response in lambs fed LCa diet were restored (P>0.05) to become at par with the control (NCa) upon supplementation of B (LCaB-40). The mRNA expression of SOD1 was lowered (P<0.05) due to LCa diet feeding which too was normalized on B-supplementation to become at par (P>0.05) with the control (NCa). Further, B-supplementation restored lowered (P<0.05) SOD1 gene expression on LCa diet, but enhanced (P<0.05) that in NCaB-40 group, when compared to the control (NCa) diet fed animals. However, these variations were not reflected in the SOD activity in the erythrocytes. The cell-mediated immune response was higher (P<0.05) in lambs fed LCa and LCaB-40 groups and there was no significant interaction between the levels of either Ca or B in diets with the period of immune response measurement. B- supplementation of LCa diet ameliorated tissue degenerative changes in liver and kidney. It was concluded that feeding LCa diet to lambs resulted in reduced growth rate, total antioxidant activity, humoral immune response along with degenerative changes in liver and kidney tissues, but B-supplementation of such diet restored most of these changes and ameliorated histopathological alterations. PMID:29141035

Hybrid life-cycle assessment (LCA) of CO2 emission with management alternatives for household food wastes in Japan.

PubMed

Inaba, Rokuta; Nansai, Keisuke; Fujii, Minoru; Hashimoto, Seiji

2010-06-01

In this study, we conducted a hybrid life-cycle assessment (LCA) to evaluate reductions in CO(2) emissions by food waste biogasification of household food wastes in Japan. Two alternative scenarios were examined. In one alternative (Ref), all combustible municipal solid wastes (MSWs), including food waste, are incinerated. In the other (Bio), food waste is biogasified, while the other combustible wastes are incinerated. An inventory analysis of energy and material flow in the MSW management system was conducted. Subsequently, the inventory data were summarized into an input-output format, and a make-use input-output framework was applied. Furthermore, a production equilibrium model was established using a matrix representing the input- output relationship of energy and materials among the processes and sectors. Several levels of power generation efficiency from incineration were applied as a sensitivity analysis. The hybrid LCA indicated that the difference between the Bio and Ref scenarios, from the perspective of CO( 2) emissions, is relatively small. However, a 13-14% reduction of CO(2) emissions of the total waste management sector in Japan may be achieved by improving the efficiency of power generation from incineration from 10% to 25%.

LIFE CYCLE ASSESSMENT: PRINCIPLES AND PRACTICE

EPA Science Inventory

The following document provides an introductory overview of Life Cycle Assessment (LCA) and describes the general uses and major components of LCA. This document is an update and merger of two previous EPA documents on LCA ("Life Cycle Assessment: Inventory Guidelines and Princip...

CASE STUDIES EXAMINING LCA STREAMLINING TECHNIQUES

EPA Science Inventory

Pressure is mounting for more streamlined Life Cycle Assessment (LCA) methods that allow for evaluations that are quick and simple, but accurate. As part of an overall research effort to develop and demonstrate streamlined LCA, the U.S. Environmental Protection Agency has funded ...

Conceptual Framework To Extend Life Cycle Assessment Using Near-Field Human Exposure Modeling and High-Throughput Tools for Chemicals.

PubMed

Csiszar, Susan A; Meyer, David E; Dionisio, Kathie L; Egeghy, Peter; Isaacs, Kristin K; Price, Paul S; Scanlon, Kelly A; Tan, Yu-Mei; Thomas, Kent; Vallero, Daniel; Bare, Jane C

2016-11-01

Life Cycle Assessment (LCA) is a decision-making tool that accounts for multiple impacts across the life cycle of a product or service. This paper presents a conceptual framework to integrate human health impact assessment with risk screening approaches to extend LCA to include near-field chemical sources (e.g., those originating from consumer products and building materials) that have traditionally been excluded from LCA. A new generation of rapid human exposure modeling and high-throughput toxicity testing is transforming chemical risk prioritization and provides an opportunity for integration of screening-level risk assessment (RA) with LCA. The combined LCA and RA approach considers environmental impacts of products alongside risks to human health, which is consistent with regulatory frameworks addressing RA within a sustainability mindset. A case study is presented to juxtapose LCA and risk screening approaches for a chemical used in a consumer product. The case study demonstrates how these new risk screening tools can be used to inform toxicity impact estimates in LCA and highlights needs for future research. The framework provides a basis for developing tools and methods to support decision making on the use of chemicals in products.

How Well Does LCA Model Land Use Impacts on Biodiversity?--A Comparison with Approaches from Ecology and Conservation.

PubMed

Curran, Michael; de Souza, Danielle Maia; Antón, Assumpció; Teixeira, Ricardo F M; Michelsen, Ottar; Vidal-Legaz, Beatriz; Sala, Serenella; Milà i Canals, Llorenç

2016-03-15

The modeling of land use impacts on biodiversity is considered a priority in life cycle assessment (LCA). Many diverging approaches have been proposed in an expanding literature on the topic. The UNEP/SETAC Life Cycle Initiative is engaged in building consensus on a shared modeling framework to highlight best-practice and guide model application by practitioners. In this paper, we evaluated the performance of 31 models from both the LCA and the ecology/conservation literature (20 from LCA, 11 from non-LCA fields) according to a set of criteria reflecting (i) model completeness, (ii) biodiversity representation, (iii) impact pathway coverage, (iv) scientific quality, and (v) stakeholder acceptance. We show that LCA models tend to perform worse than those from ecology and conservation (although not significantly), implying room for improvement. We identify seven best-practice recommendations that can be implemented immediately to improve LCA models based on existing approaches in the literature. We further propose building a "consensus model" through weighted averaging of existing information, to complement future development. While our research focuses on conceptual model design, further quantitative comparison of promising models in shared case studies is an essential prerequisite for future informed model choice.

Evaluation of Life Cycle Assessment (LCA) for Roadway Drainage Systems.

PubMed

Byrne, Diana M; Grabowski, Marta K; Benitez, Amy C B; Schmidt, Arthur R; Guest, Jeremy S

2017-08-15

Roadway drainage design has traditionally focused on cost-effectively managing water quantity; however, runoff carries pollutants, posing risks to the local environment and public health. Additionally, construction and maintenance incur costs and contribute to global environmental impacts. While life cycle assessment (LCA) can potentially capture local and global environmental impacts of roadway drainage and other stormwater systems, LCA methodology must be evaluated because stormwater systems differ from wastewater and drinking water systems to which LCA is more frequently applied. To this end, this research developed a comprehensive model linking roadway drainage design parameters to LCA and life cycle costing (LCC) under uncertainty. This framework was applied to 10 highway drainage projects to evaluate LCA methodological choices by characterizing environmental and economic impacts of drainage projects and individual components (basin, bioswale, culvert, grass swale, storm sewer, and pipe underdrain). The relative impacts of drainage components varied based on functional unit choice. LCA inventory cutoff criteria evaluation showed the potential for cost-based criteria, which performed better than mass-based criteria. Finally, the local aquatic benefits of grass swales and bioswales offset global environmental impacts for four impact categories, highlighting the need to explicitly consider local impacts (i.e., direct emissions) when evaluating drainage technologies.

Communicating LCA Results

EPA Science Inventory

Communicating about LCA can be challenging. The most effective communication format and the appropriate level of detail depend on the audience and the goal of communication. Who are the audiences, and what is communicated to each audience? When the results of the LCA are to be co...

Life cycle assessment in market, research, and policy: Harmonization beyond standardization.

PubMed

Zamagni, Alessandra; Cutaia, Laura

2015-07-01

This article introduces the special series "LCA in Market Research and Policy: Harmonization beyond standardization," which was generated from the 19th SETAC Life Cycle Assessment (LCA) Case Study Symposium held November 2013, in Rome, Italy. This collection of invited articles reflects the purpose of symposium and focuses on how LCA can support the decision-making process at all levels (i.e., in industry and policy contexts) and how LCA results can be efficiently communicated and used to support market strategies. © 2015 SETAC.

Clinical and genetic characteristics of Leber congenital amaurosis with novel mutations in known genes based on a Chinese eastern coast Han population.

PubMed

Wang, Shiyuan; Zhang, Qi; Zhang, Xiang; Wang, Zhaoyang; Zhao, Peiquan

2016-11-01

To study the genotype-phenotype characteristics of Leber congenital amaurosis (LCA) in the Chinese eastern coast Han population. Children with strictly defined LCA with novel mutations of known LCA genes identified by targeted next-generation sequencing (NGS) and a prediction of pathogenicity (in silico) were included in this study (2013-2015). Mutations were confirmed using Sanger sequencing and segregation analysis. The clinical findings were recorded, including visual function, refractive error, fundus changes, and electroretinograms (ERGs). Spectral-domain optical coherence tomography (SD-OCT) examination, fundus fluorescein angiography (FFA), and ultra-wide field scanning laser ophthalmoscopy (UWF SLO) were performed on children when available. A total of 65 patients underwent NGS for mutation screening and 45 patients were identified as carrying known LCA genes. Of these, 36(80 %) children harbored novel mutations, and they were all from the eastern coast of China. A total of 50 novel variants were identified, which covered 15 known LCA genes. GUCY2D (17 %), CEP290 (14 %), NMNAT1 (14 %), AIPL1 (11 %) and RPGRIP1 (11 %) were the five most frequently mutated genes with novel mutations. A total of four (11 %) patients with AIPL1 mutations harbored the same novel mutated allele (c.C241T p.Q81X), which was homozygous in patients 1 and 2. Unusual manifestations were detected in patient 16 who had novel mutations in CRB1 with a dense proliferative membrane adhering to the posterior retina of the right eye with numerous fine glistening crystals spreading over the retina of both eyes. Ten (40 %) of the 25 available patients who underwent SD-OCT showed a normal macular appearance using fundus photography but an abnormal macular structure using OCT imaging, most of whom presented with a thickened fovea with maldevelopment of the inner and outer retinal laminae. There may be a high frequency of AIPL1 novel mutations and a founder mutation of p.Q81X in the Chinese eastern coast Han population. Our findings of specific features in this population broaden the spectrum of novel mutations and the phenotype of LCA with ethnic and regional variations. Fundus multimodality imaging may help guide comprehensive assessments for patients with LCA.

Modular life cycle assessment of municipal solid waste management.

PubMed

Haupt, M; Kägi, T; Hellweg, S

2018-05-31

Life cycle assessment (LCA) is commonly applied to examine the environmental performance of waste management systems. The system boundaries are, however, often limited to either one tonne of material or to specific waste treatments and are, therefore, lacking a systems perspective. Here, a framework is proposed to assess complete waste management systems based on actual waste flows, assessed with a detailed material flow analysis (MFA) in a modular MFA/LCA approach. The transformation of the MFA into a product-process-matrix facilitates a direct link between MFA and LCA, therefore allowing for the assessment of variations in flows. To allow for an up-to-date and geographically specific assessment, 190 LCA modules were set up based on primary industrial data and the ecoinvent database. The LCA modules show where there have been improvements in different recycling processes over the past years (e.g. for paper recycling) and highlight that, from an environmental perspective, closed-loop recycling is not always preferable to open-loop recycling. In a case study, the Swiss municipal solid waste management system, of which there is already a detailed MFA, was modeled using the new LCA modules and applying the modular MFA/LCA approach. Five different mass flow distribution scenarios for the Swiss municipal solid waste management system were assessed to show the environmental impact of political measures and to test the sensitivity of the results to key parameters. The results of the case study highlight the importance of the dominant fractions in the overall environmental impacts assessment; while the metal fraction has the highest impact on a per kilogram basis, paper, cardboard, glass and mixed municipal solid waste were found to dominate the environmental impacts of the Swiss waste management system due to their mass. The scenarios also highlight the importance of the energy efficiency of municipal solid waste incineration plants and the credits from material substitution as key variables. In countries with advanced waste management systems such as Switzerland, there is limited improvement potential with further increases in recycling rates. In these cases, the focus of political measures should be laid on (i) the utilization of secondary materials in applications where they replace high-impact primary production, and (ii) an increased recovery of energy in waste-to-energy plants. Copyright © 2018. Published by Elsevier Ltd.

Metabolism of lithocholic and chenodeoxycholic acids in the squirrel monkey

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

Suzuki, H.; Hamada, M.; Kato, F.

1985-09-01

Metabolism of lithocholic acid (LCA) and chenodeoxycholic acid (CDCA) was studied in the squirrel monkey to clarify the mechanism of the lack of toxicity of CDCA in this animal. Radioactive LCA was administered to squirrel monkeys with biliary fistula. Most radioactivity was excreted in the bile in the form of unsulfated lithocholyltaurine. The squirrel monkey thus differs from humans and chimpanzees, which efficiently sulfate LCA, and is similar to the rhesus monkey and baboon in that LCA is poorly sulfated. When labeled CDCA was orally administered to squirrel monkeys, less than 20% of the dosed radioactivity was recovered as LCAmore » and its further metabolites in feces over 3 days, indicating that bacterial metabolism of CDCA into LCA is strikingly less than in other animals and in humans. It therefore appears that LCA, known as a hepatotoxic secondary bile acid, is not accumulated in the squirrel monkey, not because of its rapid turnover through sulfation, but because of the low order of its production.« less

Life cycle assessment needs predictive spatial modelling for biodiversity and ecosystem services

PubMed Central

Chaplin-Kramer, Rebecca; Sim, Sarah; Hamel, Perrine; Bryant, Benjamin; Noe, Ryan; Mueller, Carina; Rigarlsford, Giles; Kulak, Michal; Kowal, Virginia; Sharp, Richard; Clavreul, Julie; Price, Edward; Polasky, Stephen; Ruckelshaus, Mary; Daily, Gretchen

2017-01-01

International corporations in an increasingly globalized economy exert a major influence on the planet's land use and resources through their product design and material sourcing decisions. Many companies use life cycle assessment (LCA) to evaluate their sustainability, yet commonly-used LCA methodologies lack the spatial resolution and predictive ecological information to reveal key impacts on climate, water and biodiversity. We present advances for LCA that integrate spatially explicit modelling of land change and ecosystem services in a Land-Use Change Improved (LUCI)-LCA. Comparing increased demand for bioplastics derived from two alternative feedstock-location scenarios for maize and sugarcane, we find that the LUCI-LCA approach yields results opposite to those of standard LCA for greenhouse gas emissions and water consumption, and of different magnitudes for soil erosion and biodiversity. This approach highlights the importance of including information about where and how land-use change and related impacts will occur in supply chain and innovation decisions. PMID:28429710

Life cycle assessment needs predictive spatial modelling for biodiversity and ecosystem services

NASA Astrophysics Data System (ADS)

Chaplin-Kramer, Rebecca; Sim, Sarah; Hamel, Perrine; Bryant, Benjamin; Noe, Ryan; Mueller, Carina; Rigarlsford, Giles; Kulak, Michal; Kowal, Virginia; Sharp, Richard; Clavreul, Julie; Price, Edward; Polasky, Stephen; Ruckelshaus, Mary; Daily, Gretchen

2017-04-01

International corporations in an increasingly globalized economy exert a major influence on the planet's land use and resources through their product design and material sourcing decisions. Many companies use life cycle assessment (LCA) to evaluate their sustainability, yet commonly-used LCA methodologies lack the spatial resolution and predictive ecological information to reveal key impacts on climate, water and biodiversity. We present advances for LCA that integrate spatially explicit modelling of land change and ecosystem services in a Land-Use Change Improved (LUCI)-LCA. Comparing increased demand for bioplastics derived from two alternative feedstock-location scenarios for maize and sugarcane, we find that the LUCI-LCA approach yields results opposite to those of standard LCA for greenhouse gas emissions and water consumption, and of different magnitudes for soil erosion and biodiversity. This approach highlights the importance of including information about where and how land-use change and related impacts will occur in supply chain and innovation decisions.

Intergenerational Profiles of Socioeconomic (Dis)advantage and Obesity During the Transition to Adulthood

PubMed Central

Scharoun-Lee, Melissa; Adair, Linda S.; Popkin, Barry M.; Kaufman, Jay S.; Suchindran, Chirayath M.

2012-01-01

Investigations of socioeconomic status (SES) and health during the transition to adulthood in the United States are complicated by the later and more varied transitions in residence, employment, schooling, and social roles compared with previous generations. Parental SES is an important influence during adolescence but cannot sufficiently capture the SES of the independent young adult. Typical, single SES indicators based on income or education likely misclassify the SES of young adults who have not yet completed their education or other training, or who have entered the labor force early with ultimately lower status attainment. We use a latent class analysis (LCA) framework to characterize five intergenerational SES groups, combining multidimensional SES information from two time points—that is, adolescent (parental) and young adult (self) SES data. Associations of these groups with obesity, a high-risk health outcome in young adults, revealed nuanced relationships not seen using traditional intergenerational SES measures. In males, for example, a middle-class upbringing in adolescence and continued material advantage into adulthood was associated with nearly as high obesity as a working poor upbringing and early, detrimental transitions. This intergenerational typology of early SES exposure facilitates understanding of SES and health during young adulthood. PMID:21491185

Using non-local databases for the environmental assessment of industrial activities: The case of Latin America

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

Osses de Eicker, Margarita, E-mail: Margarita.Osses@empa.c; Hischier, Roland, E-mail: Roland.Hischier@empa.c; Hurni, Hans, E-mail: Hans.Hurni@cde.unibe.c

2010-04-15

Nine non-local databases were evaluated with respect to their suitability for the environmental assessment of industrial activities in Latin America. Three assessment methods were considered, namely Life Cycle Assessment (LCA), Environmental Impact Assessment (EIA) and air emission inventories. The analysis focused on data availability in the databases and the applicability of their international data to Latin American industry. The study showed that the European EMEP/EEA Guidebook and the U.S. EPA AP-42 database are the most suitable ones for air emission inventories, whereas the LCI database Ecoinvent is the most suitable one for LCA and EIA. Due to the data coveragemore » in the databases, air emission inventories are easier to develop than LCA or EIA, which require more comprehensive information. One strategy to overcome the limitations of non-local databases for Latin American industry is the combination of validated data from international databases with newly developed local datasets.« less

Proposal of Environmental Impact Assessment Method for Concrete in South Korea: An Application in LCA (Life Cycle Assessment)

PubMed Central

Kim, Tae Hyoung; Tae, Sung Ho

2016-01-01

This study aims to develop a system for assessing the impact of the substances discharged from concrete production process on six environmental impact categories, i.e., global warming (GWP), acidification (AP), eutrophication (EP), abiotic depletion (ADP), ozone depletion (ODP), and photochemical oxidant creation (POCP), using the life a cycle assessment (LCA) method. To achieve this, this study proposed an LCA method specifically applicable to the Korean concrete industry by adapting the ISO standards to suit the Korean situations. The proposed LCA method involves a system that performs environmental impact assessment on the basis of input information on concrete mix design, transport distance, and energy consumption in a batch plant. The Concrete Lifecycle Assessment System (CLAS) thus developed provides user-friendly support for environmental impact assessment with specialized database for concrete mix materials and energy sources. In the case analysis using the CLAS, among the substances discharged from the production of 24 MPa concrete, those contributing to GWP, AP, EP, ADP, ODP, and POCP were assessed to amount to 309 kg-CO2 eq/m3, 28.7 kg-SO2 eq/m3, 5.21 kg-PO43− eq/m3, 0.000049 kg-CFC11 eq/m3, 34 kg/m3, and 21 kg-Ethylene eq/m3, respectively. Of these six environmental impact categories selected for the LCA in this study, ordinary Portland cement (OPC) was found to contribute most intensely to GWP and POCP, and aggregates, to AP, EP, ODP, and ADP. It was also found that the mix design with increased prop proportion of recycled aggregate was found to contribute to reducing the impact in all other categories. PMID:27827843

Eco-innovation of a wooden childhood furniture set: an example of environmental solutions in the wood sector.

PubMed

González-García, Sara; García Lozano, Raúl; Moreira, M Teresa; Gabarrell, Xavier; Rieradevall i Pons, Joan; Feijoo, Gumersindo; Murphy, Richard J

2012-06-01

The environmental profile of a set of wood furniture was carried out to define the best design criteria for its eco-design. A baby cot convertible into a bed, a study desk and a bedside table were the objects of study. Two quantitative and qualitative environmental approaches were combined in order to propose improvement alternatives: Life Cycle Assessment (LCA) and Design for Environment (DfE). In the first case Life Cycle Assessment (LCA) was applied to identify the hot spots in the product system. As a next step, LCA information was used in eco-briefing to determine several improvement alternatives. A wood products company located in Catalonia (NE Spain) was assessed in detail, dividing the process into three stages: assembly, finishing and packaging. Ten impact categories were considered in the LCA study: abiotic depletion, acidification, eutrophication, global warming, ozone layer depletion, human toxicity, fresh water aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity and photochemical oxidant formation. Two processes can be considered the key environmental factors: the production of the wooden boards and electricity, with contributions of 45-68% and 14-33% respectively depending on the impact categories. Subsequently, several improvement alternatives were proposed in the eco-design process (DfE) to achieve reductions in a short-medium period of time in the environmental impact. These eco-design strategies could reduce the environmental profile of the setup by 14%. The correct methodological adaptation of the concept of eco-briefing, as a tool for communication among environmental technicians and designers, the simplification of the analytical tool used and the LCA, could facilitate the environmental analysis of a product. The results obtained provide information that can help the furniture sector to improve their environmental performance. Copyright © 2012 Elsevier B.V. All rights reserved.

Life cycle assessment of TV sets in China: a case study of the impacts of CRT monitors.

PubMed

Song, Qingbin; Wang, Zhishi; Li, Jinhui; Zeng, Xianlai

2012-10-01

Along with the rapid increase in both production and use of TV sets in China, there is an increasing awareness of the environmental impacts related to the accelerating mass production, electricity use, and waste management of these sets. This paper aims to describe the application of life cycle assessment (LCA) to investigate the environmental performance of Chinese TV sets. An assessment of the TV set device (focusing on the Cathode Ray Tube (CRT) monitor) was carried out using a detailed modular LCA based on the international standards of the ISO 14040 series. The LCA was constructed using SimaPro software version 7.2 and expressed with the Eco-indicator' 99 life cycle impact assessment method. For a sensitivity analysis of the overall LCA results, the CML method was used in order to estimate the influence of the choice of the assessment method on the results. Life cycle inventory information was compiled by Ecoinvent 2.2 databases, combined with literature and field investigations on the current Chinese situation. The established LCA study shows that the use stage of such devices has the highest environmental impact, followed by the manufacturing stage. In the manufacturing stage, the CRT and the Printed Circuit Board (PCB) are those components contributing the most environmental impacts. During the use phase, the environmental impacts are due entirely to the methods of electricity generation used to run them, since no other aspects were taken into account for this phase. The final processing step-the end-of-life stage-can lead to a clear environmental benefit when the TV sets are processed through the formal dismantling enterprises in China. Copyright © 2012 Elsevier Ltd. All rights reserved.

Environmental impact assessment and eco-friendly decision-making in civil structures.

PubMed

Kim, Sang-Hyo; Choi, Moon-Seock; Mha, Ho-Seong; Joung, Jung-Yeun

2013-09-15

This study develops two useful procedures in performing an environmental-impact assessment. One is the advanced life-cycle assessment (LCA) method, which effectively tracks the flow of materials and considers the recycling and demolition of a civil structure. The other is an eco-friendly decision-making procedure, which may effectively apply when determining the prototype of a civil structure. The advanced LCA method differs from traditional LCA procedure, as it classifies the input material prior to the impact assessment. Classification work is performed to establish independent life-cycle stages for each material. The processes of recycling and demolition are appropriately added to the life-cycle stages. The impact assessment is performed separately for the materials, and results are aggregated at the end of the analysis. The eco-friendly decision-making procedure enables designers to choose an economical, and environmentally friendly, alternative during the planning phase of the construction project. This procedure rationally amalgamates economical value and environmental effects into a single indicator. The life cycle cost (LCC) of a structure can be analysed by using conventional LCC tools, whereas the environmental impact is estimated by LCA. The results from LCC and LCA are then integrated by using either a CO2 conversion method or an analytical hierarchy process (AHP). The CO2 conversion method presents the result as a monetary value, whereas the AHP presents the result as a non-dimensional value. A practical example using a steel box girder bridge and a pre-stressed concrete (PSC) box-girder bridge is also given in order to aid the understanding of the presented procedure. Copyright © 2013 Elsevier Ltd. All rights reserved.

Life cycle assessment study of a Chinese desktop personal computer.

PubMed

Duan, Huabo; Eugster, Martin; Hischier, Roland; Streicher-Porte, Martin; Li, Jinhui

2009-02-15

Associated with the tremendous prosperity in world electronic information and telecommunication industry, there continues to be an increasing awareness of the environmental impacts related to the accelerating mass production, electricity use, and waste management of electronic and electric products (e-products). China's importance as both a consumer and supplier of e-products has grown at an unprecedented pace in recent decade. Hence, this paper aims to describe the application of life cycle assessment (LCA) to investigate the environmental performance of Chinese e-products from a global level. A desktop personal computer system has been selected to carry out a detailed and modular LCA which follows the ISO 14040 series. The LCA is constructed by SimaPro software version 7.0 and expressed with the Eco-indicator'99 life cycle impact assessment method. For a sensitivity analysis of the overall LCA results, the so-called CML method is used in order to estimate the influence of the choice of the assessment method on the result. Life cycle inventory information is complied by ecoinvent 1.3 databases, combined with literature and field investigations on the present Chinese situation. The established LCA study shows that that the manufacturing and the use of such devices are of the highest environmental importance. In the manufacturing of such devices, the integrated circuits (ICs) and the Liquid Crystal Display (LCD) are those parts contributing most to the impact. As no other aspects are taken into account during the use phase, the impact is due to the way how the electricity is produced. The final process steps--i.e. the end of life phase--lead to a clear environmental benefit if a formal and modern, up-to-date technical system is assumed, like here in this study.

Proposal of Environmental Impact Assessment Method for Concrete in South Korea: An Application in LCA (Life Cycle Assessment).

PubMed

Kim, Tae Hyoung; Tae, Sung Ho

2016-11-02

This study aims to develop a system for assessing the impact of the substances discharged from concrete production process on six environmental impact categories, i.e., global warming (GWP), acidification (AP), eutrophication (EP), abiotic depletion (ADP), ozone depletion (ODP), and photochemical oxidant creation (POCP), using the life a cycle assessment (LCA) method. To achieve this, this study proposed an LCA method specifically applicable to the Korean concrete industry by adapting the ISO standards to suit the Korean situations. The proposed LCA method involves a system that performs environmental impact assessment on the basis of input information on concrete mix design, transport distance, and energy consumption in a batch plant. The Concrete Lifecycle Assessment System (CLAS) thus developed provides user-friendly support for environmental impact assessment with specialized database for concrete mix materials and energy sources. In the case analysis using the CLAS, among the substances discharged from the production of 24 MPa concrete, those contributing to GWP, AP, EP, ADP, ODP, and POCP were assessed to amount to 309 kg-CO₂ eq/m³, 28.7 kg-SO₂ eq/m³, 5.21 kg-PO₄ 3- eq/m³, 0.000049 kg-CFC 11 eq/m³, 34 kg/m³, and 21 kg-Ethylene eq/m³, respectively. Of these six environmental impact categories selected for the LCA in this study, ordinary Portland cement (OPC) was found to contribute most intensely to GWP and POCP, and aggregates, to AP, EP, ODP, and ADP. It was also found that the mix design with increased prop proportion of recycled aggregate was found to contribute to reducing the impact in all other categories.

Life cycle assessment of TV sets in China: A case study of the impacts of CRT monitors

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

Song Qingbin; Wang Zhishi, E-mail: zswang@umac.mo; Li Jinhui

2012-10-15

Along with the rapid increase in both production and use of TV sets in China, there is an increasing awareness of the environmental impacts related to the accelerating mass production, electricity use, and waste management of these sets. This paper aims to describe the application of life cycle assessment (LCA) to investigate the environmental performance of Chinese TV sets. An assessment of the TV set device (focusing on the Cathode Ray Tube (CRT) monitor) was carried out using a detailed modular LCA based on the international standards of the ISO 14040 series. The LCA was constructed using SimaPro software versionmore » 7.2 and expressed with the Eco-indicator' 99 life cycle impact assessment method. For a sensitivity analysis of the overall LCA results, the CML method was used in order to estimate the influence of the choice of the assessment method on the results. Life cycle inventory information was compiled by Ecoinvent 2.2 databases, combined with literature and field investigations on the current Chinese situation. The established LCA study shows that the use stage of such devices has the highest environmental impact, followed by the manufacturing stage. In the manufacturing stage, the CRT and the Printed Circuit Board (PCB) are those components contributing the most environmental impacts. During the use phase, the environmental impacts are due entirely to the methods of electricity generation used to run them, since no other aspects were taken into account for this phase. The final processing step-the end-of-life stage-can lead to a clear environmental benefit when the TV sets are processed through the formal dismantling enterprises in China.« less

Use of life cycle assessments to evaluate the environmental footprint of contaminated sediment remediation.

PubMed

Sparrevik, Magnus; Saloranta, Tuomo; Cornelissen, Gerard; Eek, Espen; Fet, Annik Magerholm; Breedveld, Gijs D; Linkov, Igor

2011-05-15

Ecological and human risks often drive the selection of remedial alternatives for contaminated sediments. Traditional human and ecological risk assessment (HERA) includes assessing risk for benthic organisms and aquatic fauna associated with exposure to contaminated sediments before and after remediation as well as risk for human exposure but does not consider the environmental footprint associated with implementing remedial alternatives. Assessment of environmental effects over the whole life cycle (i.e., Life Cycle Assessment, LCA) could complement HERA and help in selecting the most appropriate sediment management alternative. Even though LCA has been developed and applied in multiple environmental management cases, applications to contaminated sediments and marine ecosystems are in general less frequent. This paper implements LCA methodology for the case of the polychlorinated dibenzo-p-dioxins and -furans (PCDD/F)-contaminated Grenland fjord in Norway. LCA was applied to investigate the environmental footprint of different active and passive thin-layer capping alternatives as compared to natural recovery. The results showed that capping was preferable to natural recovery when analysis is limited to effects related to the site contamination. Incorporation of impacts related to the use of resources and energy during the implementation of a thin layer cap increase the environmental footprint by over 1 order of magnitude, making capping inferior to the natural recovery alternative. Use of biomass-derived activated carbon, where carbon dioxide is sequestered during the production process, reduces the overall environmental impact to that of natural recovery. The results from this study show that LCA may be a valuable tool for assessing the environmental footprint of sediment remediation projects and for sustainable sediment management.

Hidden Genetic Variation in LCA9-Associated Congenital Blindness Explained by 5'UTR Mutations and Copy-Number Variations of NMNAT1.

PubMed

Coppieters, Frauke; Todeschini, Anne Laure; Fujimaki, Takuro; Baert, Annelot; De Bruyne, Marieke; Van Cauwenbergh, Caroline; Verdin, Hannah; Bauwens, Miriam; Ongenaert, Maté; Kondo, Mineo; Meire, Françoise; Murakami, Akira; Veitia, Reiner A; Leroy, Bart P; De Baere, Elfride

2015-12-01

Leber congenital amaurosis (LCA) is a severe autosomal-recessive retinal dystrophy leading to congenital blindness. A recently identified LCA gene is NMNAT1, located in the LCA9 locus. Although most mutations in blindness genes are coding variations, there is accumulating evidence for hidden noncoding defects or structural variations (SVs). The starting point of this study was an LCA9-associated consanguineous family in which no coding mutations were found in the LCA9 region. Exploring the untranslated regions of NMNAT1 revealed a novel homozygous 5'UTR variant, c.-70A>T. Moreover, an adjacent 5'UTR variant, c.-69C>T, was identified in a second consanguineous family displaying a similar phenotype. Both 5'UTR variants resulted in decreased NMNAT1 mRNA abundance in patients' lymphocytes, and caused decreased luciferase activity in human retinal pigment epithelial RPE-1 cells. Second, we unraveled pseudohomozygosity of a coding NMNAT1 mutation in two unrelated LCA patients by the identification of two distinct heterozygous partial NMNAT1 deletions. Molecular characterization of the breakpoint junctions revealed a complex Alu-rich genomic architecture. Our study uncovered hidden genetic variation in NMNAT1-associated LCA and emphasized a shift from coding to noncoding regulatory mutations and repeat-mediated SVs in the molecular pathogenesis of heterogeneous recessive disorders such as hereditary blindness. © 2015 The Authors. **Human Mutation published by Wiley Periodicals, Inc.

Prevalence and patterns of smoking, alcohol use, and illicit drug use in young men who have sex with men.

PubMed

Newcomb, Michael E; Ryan, Daniel T; Greene, George J; Garofalo, Robert; Mustanski, Brian

2014-08-01

Young men who have sex with men (YMSM) are substantially more likely to use illicit drugs and other substances compared to their heterosexual peers. Substance use during adolescence has critical implications for long-term physical and mental health, and among YMSM may lead to HIV infection. The goal of the current study was to describe lifetime and past six month prevalence and patterns of substance use across multiple substances in a community sample of racially-diverse YMSM. Participants were 450 YMSM aged 16-20 living in Chicago and surrounding areas who were recruited beginning December, 2009 using a modified form of respondent driven sampling. Analyses were conducted with multivariate logistic regression and latent class analysis (LCA). Prevalence of substance use was high in this sample of majority racial minority YMSM, and only 17.6% reported no substance use during the past six months. Black YMSM had lower prevalence of use of all substances except marijuana compared to White YMSM, while Latino YMSM had lower prevalence of alcohol, marijuana, and club drug use. Bisexual YMSM reported higher prevalence of cigarette smoking, stimulant use, and club drug use compared to gay/mostly gay YMSM but lower numbers of bisexual participants limited the ability to detect statistically significant differences. LCA found that YMSM fell into three general categories of substance users: alcohol and marijuana users, polysubstance users, and low marijuana users. Analyses reveal important group differences in prevalence and patterns of substance use in YMSM that have important implications for intervention. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The Opportunities and Pitfalls of Applying Life Cycle Thinking to Nanoproducts and Nanomaterials

EPA Science Inventory

Life Cycle Assessment (LCA) is a well-established methodology for evaluating the environmental impact of products, materials, and processes. LCA experts worldwide agree that existing LCA tools are capable of supporting the development of decisions on the use of nanomaterials and ...

Life Cycle Comparison of Waste-to-Energy to Sanitary Landfill

EPA Science Inventory

Life cycle assessment (LCA) can be used to evaluate the environmental footprint of products, processes, and services. An LCA allows decision makers to compare products and processes through systematic evaluation of supply chains. Also known as a “cradle-to-grave” approach, LCA ev...

Comparative Genomics and Transcriptional Analysis of Prophages Identified in the Genomes of Lactobacillus gasseri, Lactobacillus salivarius, and Lactobacillus casei†

PubMed Central

Ventura, Marco; Canchaya, Carlos; Bernini, Valentina; Altermann, Eric; Barrangou, Rodolphe; McGrath, Stephen; Claesson, Marcus J.; Li, Yin; Leahy, Sinead; Walker, Carey D.; Zink, Ralf; Neviani, Erasmo; Steele, Jim; Broadbent, Jeff; Klaenhammer, Todd R.; Fitzgerald, Gerald F.; O'Toole, Paul W.; van Sinderen, Douwe

2006-01-01

Lactobacillus gasseri ATCC 33323, Lactobacillus salivarius subsp. salivarius UCC 118, and Lactobacillus casei ATCC 334 contain one (LgaI), four (Sal1, Sal2, Sal3, Sal4), and one (Lca1) distinguishable prophage sequences, respectively. Sequence analysis revealed that LgaI, Lca1, Sal1, and Sal2 prophages belong to the group of Sfi11-like pac site and cos site Siphoviridae, respectively. Phylogenetic investigation of these newly described prophage sequences revealed that they have not followed an evolutionary development similar to that of their bacterial hosts and that they show a high degree of diversity, even within a species. The attachment sites were determined for all these prophage elements; LgaI as well as Sal1 integrates in tRNA genes, while prophage Sal2 integrates in a predicted arginino-succinate lyase-encoding gene. In contrast, Lca1 and the Sal3 and Sal4 prophage remnants are integrated in noncoding regions in the L. casei ATCC 334 and L. salivarius UCC 118 genomes. Northern analysis showed that large parts of the prophage genomes are transcriptionally silent and that transcription is limited to genome segments located near the attachment site. Finally, pulsed-field gel electrophoresis followed by Southern blot hybridization with specific prophage probes indicates that these prophage sequences are narrowly distributed within lactobacilli. PMID:16672450

What Can Meta-Analyses Tell Us About the Reliability of Life Cycle Assessment for Decision Support?

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

Brandao, M.; Heath, G.; Cooper, J.

2012-04-01

The body of life cycle assessment (LCA) literature is vast and has grown over the last decade at a dauntingly rapid rate. Many LCAs have been published on the same or very similar technologies or products, in some cases leading to hundreds of publications. One result is the impression among decision makers that LCAs are inconclusive, owing to perceived and real variability in published estimates of life cycle impacts. Despite the extensive available literature and policy need formore conclusive assessments, only modest attempts have been made to synthesize previous research. A significant challenge to doing so are differences in characteristicsmore » of the considered technologies and inconsistencies in methodological choices (e.g., system boundaries, coproduct allocation, and impact assessment methods) among the studies that hamper easy comparisons and related decision support. An emerging trend is meta-analysis of a set of results from LCAs, which has the potential to clarify the impacts of a particular technology, process, product, or material and produce more robust and policy-relevant results. Meta-analysis in this context is defined here as an analysis of a set of published LCA results to estimate a single or multiple impacts for a single technology or a technology category, either in a statistical sense (e.g., following the practice in the biomedical sciences) or by quantitative adjustment of the underlying studies to make them more methodologically consistent. One example of the latter approach was published in Science by Farrell and colleagues (2006) clarifying the net energy and greenhouse gas (GHG) emissions of ethanol, in which adjustments included the addition of coproduct credit, the addition and subtraction of processes within the system boundary, and a reconciliation of differences in the definition of net energy metrics. Such adjustments therefore provide an even playing field on which all studies can be considered and at the same time specify the conditions of the playing field itself. Understanding the conditions under which a meta-analysis was conducted is important for proper interpretation of both the magnitude and variability in results. This special supplemental issue of the Journal of Industrial Ecology includes 12 high-quality metaanalyses and critical reviews of LCAs that advance understanding of the life cycle environmental impacts of different technologies, processes, products, and materials. Also published are three contributions on methodology and related discussions of the role of meta-analysis in LCA. The goal of this special supplemental issue is to contribute to the state of the science in LCA beyond the core practice of producing independent studies on specific products or technologies by highlighting the ability of meta-analysis of LCAs to advance understanding in areas of extensive existing literature. The inspiration for the issue came from a series of meta-analyses of life cycle GHG emissions from electricity generation technologies based on research from the LCA Harmonization Project of the National Renewable Energy Laboratory (NREL), a laboratory of the U.S. Department of Energy, which also provided financial support for this special supplemental issue. (See the editorial from this special supplemental issue [Lifset 2012], which introduces this supplemental issue and discusses the origins, funding, peer review, and other aspects.) The first article on reporting considerations for meta-analyses/critical reviews for LCA is from Heath and Mann (2012), who describe the methods used and experience gained in NREL's LCA Harmonization Project, which produced six of the studies in this special supplemental issue. Their harmonization approach adapts key features of systematic review to identify and screen published LCAs followed by a meta-analytical procedure to adjust published estimates to ones based on a consistent set of methods and assumptions to allow interstudy comparisons and conclusions to be made. In a second study on methods, Zumsteg and colleagues (2012) propose a checklist for a standardized technique to assist in conducting and reporting systematic reviews of LCAs, including meta-analysis, that is based on a framework used in evidence-based medicine. Widespread use of such a checklist would facilitate planning successful reviews, improve the ability to identify systematic reviews in literature searches, ease the ability to update content in future reviews, and allow more transparency of methods to ease peer review and more appropriately generalize findings. Finally, Zamagni and colleagues (2012) propose an approach, inspired by a meta-analysis, for categorizing main methodological topics, reconciling diverging methodological developments, and identifying future research directions in LCA. Their procedure involves the carrying out of a literature review on articles selected according to predefined criteria.« less

The influence of catalysts on biofuel life cycle analysis (LCA)

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

Benavides, Pahola Thathiana; Cronauer, Donald C.; Adom, Felix K.

Catalysts play an important role in biofuel production but are rarely included in biofuel life cycle analysis (LCA). In this work, we estimate the cradle-to-gate energy consumption and greenhouse gas (GHG) emissions of Pt/γ-Al 2O 3, CoMo/γ-Al 2O 3, and ZSM-5, catalysts that could be used in processes to convert biomass to biofuels. We also consider the potential impacts of catalyst recovery and recycling. Integrating the energy and environmental impacts of CoMo/γ-Al 2O 3 and ZSM-5 into an LCA of renewable gasoline produced via in-situ and ex-situ fast pyrolysis of a blended woody feedstock revealed that the ZSM-5, with cradle-to-gatemore » GHG emissions of 7.7 kg CO 2e/kg, could influence net life-cycle GHG emissions of the renewable gasoline (1.7 gCO 2e/MJ for the in-situ process, 1.2 gCO 2e/MJ for the ex-situ process) by up to 14% depending on the loading rate. CoMo/γ-Al 2O 3 had a greater GHG intensity (9.6 kg CO 2e/kg) than ZSM-5, however, it contributed approximately only 1% to the life-cycle GHG emissions of the renewable gasoline because of the small amount of this catalyst needed per kg of biofuel produced. As a result, given that catalysts can contribute significantly to biofuel life-cycle GHG emissions depending on the GHG intensity of their production and their consumption rates, biofuel LCAs should consider the potential influence of catalysts on LCA results.« less

The influence of catalysts on biofuel life cycle analysis (LCA)

DOE PAGES

Benavides, Pahola Thathiana; Cronauer, Donald C.; Adom, Felix K.; ...

2017-01-21

Catalysts play an important role in biofuel production but are rarely included in biofuel life cycle analysis (LCA). In this work, we estimate the cradle-to-gate energy consumption and greenhouse gas (GHG) emissions of Pt/γ-Al 2O 3, CoMo/γ-Al 2O 3, and ZSM-5, catalysts that could be used in processes to convert biomass to biofuels. We also consider the potential impacts of catalyst recovery and recycling. Integrating the energy and environmental impacts of CoMo/γ-Al 2O 3 and ZSM-5 into an LCA of renewable gasoline produced via in-situ and ex-situ fast pyrolysis of a blended woody feedstock revealed that the ZSM-5, with cradle-to-gatemore » GHG emissions of 7.7 kg CO 2e/kg, could influence net life-cycle GHG emissions of the renewable gasoline (1.7 gCO 2e/MJ for the in-situ process, 1.2 gCO 2e/MJ for the ex-situ process) by up to 14% depending on the loading rate. CoMo/γ-Al 2O 3 had a greater GHG intensity (9.6 kg CO 2e/kg) than ZSM-5, however, it contributed approximately only 1% to the life-cycle GHG emissions of the renewable gasoline because of the small amount of this catalyst needed per kg of biofuel produced. As a result, given that catalysts can contribute significantly to biofuel life-cycle GHG emissions depending on the GHG intensity of their production and their consumption rates, biofuel LCAs should consider the potential influence of catalysts on LCA results.« less

Water use implications of biofuel scenarios

NASA Astrophysics Data System (ADS)

Teter, J.; Mishra, G. S.; Yeh, S.

2012-12-01

Existing studies rely upon attributional lifecycle analysis (LCA) approaches to estimate water intensity of biofuels in liters of irrigated/evapotranspiration water consumed for biofuel production. Such approaches can be misleading. From a policy perspective, a better approach is to compare differential water impacts among scenarios on a landscape scale. We address the shortcomings of existing studies by using consequential LCA, and incorporate direct and indirect land use (changes) of biofuel scenarios, marginal vs. average biofuel water use estimates, future climate, and geographic heterogeneity. We use the outputs of a partial equilibrium economic model, climate and soil data, and a process-based crop-soil-climate-water model to estimate differences in green water (GW - directly from precipitation to soil) and blue water (BW - supplied by irrigation) use among three scenarios: (1) business-as-usual (BAU), (2) Renewable Fuels Standard (RFS) mandates, and (3) a national Low Carbon Fuel Standard (LCFS) plus the RFS scenario. We use spatial statistical methods to interpolate key climatic variables using daily climate observations for the contiguous USA. Finally, we use FAO's crop model AquaCrop to estimate the domestic GW and BW impacts of biofuel policies from 2007-2035. We assess the differences among scenarios along the following metrics: (1) crop area expansion at the county level, including prime and marginal lands, (2) crop-specific and overall annual/seasonal water balances including (a) water inflows (irrigation & precipitation), (b) crop-atmosphere interactions: (evaporation & transpiration) and (d) soil-water flows (runoff & soil infiltration), in mm 3 /acre over the relevant time period. The functional unit of analysis is the BW and GW requirements of biofuels (mm3 per Btu biofuel) at the county level. Differential water use impacts among scenarios are a primarily a function of (1) land use conversion, in particular that of formerly uncropped land classes (2) irrigation practices, (3) feedstock water use efficiency, and (4) the longer growing season and a predominance of rainfed cultivation of dedicated biofuel feedstocks. National-level total water use is lowest in the BAU scenario and highest in the RFS2 + LCFS scenario. Figure: Million acres converted to growing miscanthus (top) & switchgrass (bottom) under the RFS + LCFS scenario in 2035. Land use classes are crop pasture (blue), idle cropland (red-purple) & prime cropland (brown).

Examining the need assessment process by identifying the need profiles of elderly care recipients in the Ten-year Long-Term Care Project (TLTCP) of Taiwan.

PubMed

Liu, Li-Fan; Yao, Hui-Ping

2014-12-01

To deal with the increasing long-term care (LTC) needs of elderly people in Taiwan, the government launched the Ten-year Long-term Care Project (TLTCP) in 2007, and through the care management system, care plans for those in need were distributed and implemented by care managers according to the single assessment process. Based on the emphasis of linking the right need assessment to the care plan, this study aimed to explore the need profiles of LTC recipients with regard to their health indicators to serve as a validity check on the identified dependency levels and care plans in the current care management system. A model based on latent class analysis (LCA) was used for dealing with the issue of health heterogeneity. LCA provides an empirical method that examines the interrelationships among health indicators and characterizes the underlying set of mutually exclusive latent classes that account for the observed indicators. The analysis included a total of 2901 elderly care recipients in the LTC dataset from a southern city, 1 of the 5 major metropolitan areas in Taiwan. The identified dependency levels of the samples and their care plans in need assessment were compared and discussed. Four need profiles were explored in the LTC dataset. Apart from the low (LD) (32.95%) and moderate dependent groups (MD) (17.48%), there were 2 groups identified among the high-dependency levels, including the severe physical and psychological dependency (SPP) (26.37%) and the comorbidities and severe dependency (CSD) groups (23.20%), which in sum were approximately identified as high dependency (HD) by care managers in the LTC dataset. In addition, the CSD group currently costs more for their care plans on average in LTC services (NT. 277,081.15, approximately 9200 USD) than the SPP group (NT. 244,084.21) and the other groups. Need assessment is a key to success in care management in LTC. The results of this study showed the importance of focusing on multifacet indicators, especially the mental and social health indicators in need assessments by improving the unified assessment process to sensitively detect those with various needs and then link them to the right care plan. Copyright © 2014 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

FUNDAMENTALS OF LIFE CYCLE ASSESSMENT AND OFF-THE-SHELF SOFTWARE DEMONSTRATION

EPA Science Inventory

As the name implies, Life Cycle Assesssment (LCA) evaluates the entire life cycle of a product, process, activity, or service, not just simple economics at the time of delivery. This course on LCA covers the following issues:
Basic principles of LCA for use in producing, des...

Improved Environmental Life Cycle Assessment of Crop Production at the Catchment Scale via a Process-Based Nitrogen Simulation Model.

PubMed

Liao, Wenjie; van der Werf, Hayo M G; Salmon-Monviola, Jordy

2015-09-15

One of the major challenges in environmental life cycle assessment (LCA) of crop production is the nonlinearity between nitrogen (N) fertilizer inputs and on-site N emissions resulting from complex biogeochemical processes. A few studies have addressed this nonlinearity by combining process-based N simulation models with LCA, but none accounted for nitrate (NO3(-)) flows across fields. In this study, we present a new method, TNT2-LCA, that couples the topography-based simulation of nitrogen transfer and transformation (TNT2) model with LCA, and compare the new method with a current LCA method based on a French life cycle inventory database. Application of the two methods to a case study of crop production in a catchment in France showed that, compared to the current method, TNT2-LCA allows delineation of more appropriate temporal limits when developing data for on-site N emissions associated with specific crops in this catchment. It also improves estimates of NO3(-) emissions by better consideration of agricultural practices, soil-climatic conditions, and spatial interactions of NO3(-) flows across fields, and by providing predicted crop yield. The new method presented in this study provides improved LCA of crop production at the catchment scale.

Conceptual Framework To Extend Life Cycle Assessment ...

EPA Pesticide Factsheets

Life Cycle Assessment (LCA) is a decision-making tool that accounts for multiple impacts across the life cycle of a product or service. This paper presents a conceptual framework to integrate human health impact assessment with risk screening approaches to extend LCA to include near-field chemical sources (e.g., those originating from consumer products and building materials) that have traditionally been excluded from LCA. A new generation of rapid human exposure modeling and high-throughput toxicity testing is transforming chemical risk prioritization and provides an opportunity for integration of screening-level risk assessment (RA) with LCA. The combined LCA and RA approach considers environmental impacts of products alongside risks to human health, which is consistent with regulatory frameworks addressing RA within a sustainability mindset. A case study is presented to juxtapose LCA and risk screening approaches for a chemical used in a consumer product. The case study demonstrates how these new risk screening tools can be used to inform toxicity impact estimates in LCA and highlights needs for future research. The framework provides a basis for developing tools and methods to support decision making on the use of chemicals in products. This paper presents a conceptual framework for including near-field exposures into Life Cycle Assessment using advanced human exposure modeling and high-throughput tools

Environmental impacts of organic and conventional agricultural products--are the differences captured by life cycle assessment?

PubMed

Meier, Matthias S; Stoessel, Franziska; Jungbluth, Niels; Juraske, Ronnie; Schader, Christian; Stolze, Matthias

2015-02-01

Comprehensive assessment tools are needed that reliably describe environmental impacts of different agricultural systems in order to develop sustainable high yielding agricultural production systems with minimal impacts on the environment. Today, Life Cycle Assessment (LCA) is increasingly used to assess and compare the environmental sustainability of agricultural products from conventional and organic agriculture. However, LCA studies comparing agricultural products from conventional and organic farming systems report a wide variation in the resource efficiency of products from these systems. The studies show that impacts per area farmed land are usually less in organic systems, but related to the quantity produced impacts are often higher. We reviewed 34 comparative LCA studies of organic and conventional agricultural products to analyze whether this result is solely due to the usually lower yields in organic systems or also due to inaccurate modeling within LCA. Comparative LCAs on agricultural products from organic and conventional farming systems often do not adequately differentiate the specific characteristics of the respective farming system in the goal and scope definition and in the inventory analysis. Further, often only a limited number of impact categories are assessed within the impact assessment not allowing for a comprehensive environmental assessment. The most critical points we identified relate to the nitrogen (N) fluxes influencing acidification, eutrophication, and global warming potential, and biodiversity. Usually, N-emissions in LCA inventories of agricultural products are based on model calculations. Modeled N-emissions often do not correspond with the actual amount of N left in the system that may result in potential emissions. Reasons for this may be that N-models are not well adapted to the mode of action of organic fertilizers and that N-emission models often are built on assumptions from conventional agriculture leading to even greater deviances for organic systems between the amount of N calculated by emission models and the actual amount of N available for emissions. Improvements are needed regarding a more precise differentiation between farming systems and regarding the development of N emission models that better represent actual N-fluxes within different systems. We recommend adjusting N- and C-emissions during farmyard manure management and farmyard manure fertilization in plant production to the feed ration provided in the animal production of the respective farming system leading to different N- and C-compositions within the excrement. In the future, more representative background data on organic farming systems (e.g. N content of farmyard manure) should be generated and compiled so as to be available for use within LCA inventories. Finally, we recommend conducting consequential LCA - if possible - when using LCA for policy-making or strategic environmental planning to account for different functions of the analyzed farming systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

U.S. EPA'S RESEARCH ON LIFE-CYCLE ANALYSIS

EPA Science Inventory

Life-cycle analysis (LCA) consists of looking at a product, process or activity from its inception through its completion. or consumer products, this includes the stages of raw material acquisition, manufacturing and fabrication, distribution, consumer use/reuse and final disposa...

From the LCA of food products to the environmental assessment of protected crops districts: a case-study in the south of Italy.

PubMed

Cellura, Maurizio; Ardente, Fulvio; Longo, Sonia

2012-01-01

In the present study, Life Cycle Assessment (LCA) methodology was applied to evaluate the energy consumption and environmental burdens associated with the production of protected crops in an agricultural district in the Mediterranean region. In this study, LCA was used as a 'support tool', to address local policies for sustainable production and consumption patterns, and to create a 'knowledge base' for environmental assessment of an extended agricultural production area. The proposed approach combines organisation-specific tools, such as Environmental Management Systems and Environmental Product Declarations, with the environmental management of the district. Questionnaires were distributed to producers to determine the life cycle of different protected crops (tomatoes, cherry tomatoes, peppers, melons and zucchinis), and obtain information on greenhouse usage (e.g. tunnel vs. pavilion). Ecoprofiles of products in the district were also estimated, to identify supply chain elements with the highest impact in terms of global energy requirements, greenhouse gas emissions, eutrophication, water consumption and waste production. These results of this study enable selection of the 'best practices' and ecodesign solutions, to reduce the environmental impact of these products. Finally, sensitivity analysis of key LCA issues was performed, to assess the variability associated with different parameters: vegetable production; water usage; fertiliser and pesticide usage; shared greenhouse use; substitution of plastics coverings; and waste recycling. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prospective time-resolved LCA of fully electric supercap vehicles in Germany.

PubMed

Zimmermann, Benedikt M; Dura, Hanna; Baumann, Manuel J; Weil, Marcel R

2015-07-01

The ongoing transition of the German electricity supply toward a higher share of renewable and sustainable energy sources, called Energiewende in German, has led to dynamic changes in the environmental impact of electricity over the last few years. Prominent scenario studies predict that comparable dynamics will continue in the coming decades, which will further improve the environmental performance of Germany's electricity supply. Life cycle assessment (LCA) is the methodology commonly used to evaluate environmental performance. Previous LCA studies on electric vehicles have shown that the electricity supply for the vehicles' operation is responsible for the major part of their environmental impact. The core question of this study is how the prospective dynamic development of the German electricity mix will affect the impact of electric vehicles operated in Germany and how LCA can be adapted to analyze this impact in a more robust manner. The previously suggested approach of time-resolved LCA, which is located between static and dynamic LCA, is used in this study and compared with several static approaches. Furthermore, the uncertainty issue associated with scenario studies is addressed in general and in relation to time-resolved LCA. Two scenario studies relevant to policy making have been selected, but a moderate number of modifications have been necessary to adapt the data to the requirements of a life cycle inventory. A potential, fully electric vehicle powered by a supercapacitor energy storage system is used as a generic example. The results show that substantial improvements in the environmental repercussions of the electricity supply and, consequentially, of electric vehicles will be achieved between 2020 and 2031 on the basis of the energy mixes predicted in both studies. This study concludes that although scenarios might not be able to predict the future, they should nonetheless be used as data sources in prospective LCA studies, because in many cases historic data appears to be unsuitable for providing realistic information on the future. The time-resolved LCA approach improves the assessment's robustness substantially, especially when nonlinear developments are foreseen in the future scenarios. This allows for a reduction of bias in LCA-based decision making. However, a deeper integration of time-resolved data in the life cycle inventory and the implementation of a more suitable software framework are desirable. The study describes how life cycle assessment's (LCA) robustness can be improved by respecting prospective fluctuations, like the transition of the German electricity mix, in the modeling of the life cycle inventory. It presents a feasible and rather simple process to add time-resolved data to LCA. The study selects 2 different future scenarios from important German studies and processes their data systematically to make them compatible with the requirements of a life cycle inventory. The use of external scenarios as basis for future-oriented LCA is reflected critically. A case study on electric mobility is presented and used to compare historic, prospective static, and prospective time-resolved electricity mix modeling approaches. The case study emphasizes the benefits of time-resolved LCA in direct comparison with the currently used approaches. © 2015 SETAC.

Life of Sugar: Developing Lifecycle Methods to Evaluate the Energy and Environmental Impacts of Sugarcane Biofuels

NASA Astrophysics Data System (ADS)

Gopal, Anand Raja

Lifecycle Assessment (LCA) is undergoing a period of rapid change as it strives to become more policy-relevant. Attributional LCA, the traditional LCA category, is beginning to be seen as particularly ill-equipped to assess the consequences of a policy. This has given birth to a new category of LCA known as Consequential LCA that is designed for use in LCA-based policies but is still largely unknown, even to LCA experts, and suffers from a lack of well developed methods. As a result, many LCA-based policies, like the California Low Carbon Fuel Standard (LCFS), use poor LCA methods that are both scientifically suspect and unable to model many biofuels, especially ones manufactured from byproduct feedstocks. Biofuels made from byproduct feedstocks, primarily molasses ethanol from Asia and the Caribbean, can contribute significantly to LCFS' carbon intensity targets in the near-term at low costs, a desperate need for the policy ever since US corn ethanol was rated as having a worse global warming impact than gasoline. In this dissertation, I develop the first fully consequential lifecycle assessment of a byproduct-based biofuel using a partial equilibrium foundation. I find that the lifecycle carbon content of Indian molasses ethanol is just 5 gCO2/MJ using this method, making it one of the cleanest first generation biofuels in the LCFS. I also show that Indian molasses ethanol remains one of the cleanest first-generation biofuels even when using the flawed methodology ratified for the LCFS, with a lifecycle carbon content of 24 gCO2/MJ. My fully consequential LCA model also shows that India's Ethanol Blending program, which currently subsidizes blending of molasses ethanol and gasoline for domestic consumption, can meet its objective of supporting domestic agriculture more cost-effectively by helping producers export their molasses ethanol to fuel markets that value carbon. However, this objective will be achieved at a significant cost to the poor who will face a 39% increase in the price of sorghum because of the policy.

Differential Roles for the Thyroarytenoid and Lateral Cricoarytenoid Muscles in Phonation

PubMed Central

Chhetri, Dinesh K.; Neubauer, Juergen

2015-01-01

Objective Laryngeal adductor muscle dysfunction is common cause of voice disorders. Reconstitution of adductor muscle function is often the target of therapy, but the effects of these muscles on voice production remain to be fully understood. This study investigated the differential roles of thyroarytenoid (TA) and lateral cricoarytenoid (LCA) muscles on voice production. Study Design Basic science study using an in vivo canine model of phonation. Methods The TA and LCA muscle nerve branches were stimulated to obtain 7 graded levels of muscle activation, from threshold to maximal contraction. The effects of LCA activation alone, TA activation alone, and combined TA and LCA activation on phonation onset parameters were investigated. Phonatory posture, phonation onset type, fundamental frequency (F0), phonation onset pressure, and airflow were evaluated. Results LCA activation closed the posterior glottis but mid-membranous gap remained. TA activation closed the membranous glottis but posterior gap remained. Complete glottal closure was obtained only with combined TA and LCA activation. Phonation onset with LCAs alone was characterized by multiple modes (soft, aperiodic, periodic), while with TAs alone was abrupt and periodic but had significant baseline noise. Combined muscle activation led to elimination of baseline noise with stable abrupt periodic onset of phonation. Combined muscle activation was also necessary for F0 variation. LCA assisted the TA in increasing subglottal pressure while concurrently reducing phonation onset airflow. Conclusion TA is necessary for F0 variation, stable onset phonation, and increased subglottal pressure but needs LCA for optimal effectiveness and to reduce airflow requirements with increased activation. PMID:26198167

Sleep-related changes in cardiovascular autonomic regulation in left coronary artery ligation rats: Neural mechanism facilitating arrhythmia after myocardial infarction.

PubMed

Lin, Wei-Lun; Lo, Li-Wei; Chen, Hau-Ruey; Lai, Chun-Ting; Yamada, Shinya; Liu, Shin-Huei; Chou, Yu-Hui; Chen, Shih-Ann; Fu, Yun-Ching; Kuo, Terry B J

2016-12-15

Autonomic imbalance with increased sympathetic and decreased parasympathetic activities is observed in patients after myocardial infarction (MI). We aimed to investigate sleep-related changed in autonomic regulation in left coronary artery (LCA) ligation rats. Wireless transmission of polysomnographic recording was performed in sham and LCA ligation male rats during normal daytime sleep with and without atenolol treatment. Spectral analyses of the electroencephalogram (EEG) and electromyogram (EMG) were evaluated to define active waking (AW), quiet and paradoxical sleeps (QS, PS). Cardiac autonomic activities were measured by analyzing the power spectrum of heart rate variability (HRV). EEG, EMG and HRV were recorded over 6h for consecutive 3days in all groups. In LCA ligation group, there were higher LF and LF/HF ratio on QS phase, but not AW and PS phases, compared to atenolol treated sham and LCA ligation groups, respectively. The HF component was not significantly changed on all groups in both sleep and awake phases. Sleep interruption was more frequent in LCA ligation rats compared to sham, and it was not found in LCA ligation with atenolol treatment group. Increased AW, PS and decreased QS time were noted in LCA ligation group, compared to sham and it was restored to baseline in LCA ligation with atenolol treatment group. Our results demonstrate significant sleep fragmentations with sympathetic hyperactivity during QS stages after MI, and atenolol could restore the autonomic dysfunction and sleep disturbance. The finding explains the cause of sleep-related fetal arrhythmia and sudden cardiac death after MI. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Life cycle assessment for emerging materials: case study of a garden bed constructed from lumber produced with three different copper treatments

EPA Science Inventory

Although important data and methodological challenges facing LCA and emerging materials exist, this LCA captures material and process changes that are important drivers of environmental impacts. LCA methods need to be amended to reflect properties of emerging materials that deter...

Temporal Considerations of Carbon Sequestration in LCA

Treesearch

James Salazar; Richard Bergman

2013-01-01

Accounting for carbon sequestration in LCA illustrates the limitations of a single global warming characterization factor. Typical cradle-to-grave LCA models all emissions from end-of-life processes and then characterizes these flows by IPCC GWP (100-yr) factors. A novel method estimates climate change impact by characterizing annual emissions with the IPCC GHG forcing...

Quantified Uncertainties in Comparative Life Cycle Assessment: What Can Be Concluded?

PubMed Central

2018-01-01

Interpretation of comparative Life Cycle Assessment (LCA) results can be challenging in the presence of uncertainty. To aid in interpreting such results under the goal of any comparative LCA, we aim to provide guidance to practitioners by gaining insights into uncertainty-statistics methods (USMs). We review five USMs—discernibility analysis, impact category relevance, overlap area of probability distributions, null hypothesis significance testing (NHST), and modified NHST–and provide a common notation, terminology, and calculation platform. We further cross-compare all USMs by applying them to a case study on electric cars. USMs belong to a confirmatory or an exploratory statistics’ branch, each serving different purposes to practitioners. Results highlight that common uncertainties and the magnitude of differences per impact are key in offering reliable insights. Common uncertainties are particularly important as disregarding them can lead to incorrect recommendations. On the basis of these considerations, we recommend the modified NHST as a confirmatory USM. We also recommend discernibility analysis as an exploratory USM along with recommendations for its improvement, as it disregards the magnitude of the differences. While further research is necessary to support our conclusions, the results and supporting material provided can help LCA practitioners in delivering a more robust basis for decision-making. PMID:29406730

Lithocholic bile acid inhibits lipogenesis and induces apoptosis in breast cancer cells.

PubMed

Luu, Trang H; Bard, Jean-Marie; Carbonnelle, Delphine; Chaillou, Chloé; Huvelin, Jean-Michel; Bobin-Dubigeon, Christine; Nazih, Hassan

2018-02-01

It has amply been documented that mammary tumor cells may exhibit an increased lipogenesis. Biliary acids are currently recognized as signaling molecules in the intestine, in addition to their classical roles in the digestion and absorption of lipids. The aim of our study was to evaluate the impact of lithocholic acid (LCA) on the lipogenesis of breast cancer cells. The putative cytotoxic effects of LCA on these cells were also examined. The effects of LCA on breast cancer-derived MCF-7 and MDA-MB-231 cells were studied using MTT viability assays, Annexin-FITC and Akt phosphorylation assays to evaluate anti-proliferative and pro-apoptotic properties, qRT-PCR and Western blotting assays to assess the expression of the bile acid receptor TGR5 and the estrogen receptor ERα, and genes and proteins involved in apoptosis (Bax, Bcl-2, p53) and lipogenesis (SREBP-1c, FASN, ACACA). Intracellular lipid droplets were visualized using Oil Red O staining. We found that LCA induces TGR5 expression and exhibits anti-proliferative and pro-apoptotic effects in MCF-7 and MDA-MB-231 cells. Also, an increase in pro-apoptotic p53 protein expression and a decrease in anti-apoptotic Bcl-2 protein expression were observed after LCA treatment of MCF-7 cells. In addition, we found that LCA reduced Akt phosphorylation in MCF-7 cells, but not in MDA-MB-231 cells. We also noted that LCA reduced the expression of SREBP-1c, FASN and ACACA in both breast cancer-derived cell lines and that cells treated with LCA contained low numbers of lipid droplets compared to untreated control cells. Finally, a decrease in ERα expression was observed in MCF-7 cells treated with LCA. Our data suggest a potential therapeutic role of lithocholic acid in breast cancer cells through a reversion of lipid metabolism deregulation.

Eco-efficiency for greenhouse gas emissions mitigation of municipal solid waste management: a case study of Tianjin, China.

PubMed

Zhao, Wei; Huppes, Gjalt; van der Voet, Ester

2011-06-01

The issue of municipal solid waste (MSW) management has been highlighted in China due to the continually increasing MSW volumes being generated and the limited capacity of waste treatment facilities. This article presents a quantitative eco-efficiency (E/E) analysis on MSW management in terms of greenhouse gas (GHG) mitigation. A methodology for E/E analysis has been proposed, with an emphasis on the consistent integration of life cycle assessment (LCA) and life cycle costing (LCC). The environmental and economic impacts derived from LCA and LCC have been normalized and defined as a quantitative E/E indicator. The proposed method was applied in a case study of Tianjin, China. The study assessed the current MSW management system, as well as a set of alternative scenarios, to investigate trade-offs between economy and GHG emissions mitigation. Additionally, contribution analysis was conducted on both LCA and LCC to identify key issues driving environmental and economic impacts. The results show that the current Tianjin's MSW management system emits the highest GHG and costs the least, whereas the situation reverses in the integrated scenario. The key issues identified by the contribution analysis show no linear relationship between the global warming impact and the cost impact in MSW management system. The landfill gas utilization scenario is indicated as a potential optimum scenario by the proposed E/E analysis, given the characteristics of MSW, technology levels, and chosen methodologies. The E/E analysis provides an attractive direction towards sustainable waste management, though some questions with respect to uncertainty need to be discussed further. Copyright © 2011 Elsevier Ltd. All rights reserved.

Photo-switching of a non-ionic azobenzene amphiphile in Langmuir and Langmuir-Blodgett films.

PubMed

Piosik, Emilia; Kotkowiak, Michał; Korbecka, Izabela; Galewski, Zbigniew; Martyński, Tomasz

2017-08-30

The concept of programmable and reconfigurable soft matter has emerged in science in the last few decades and can be realized by photoisomerization of azobenzene derivatives. This possibility results in great application potential of these compounds in optical storage devices, molecular junctions of electronic devices, command layers of liquid crystal displays or holographic gratings. In this paper, we present the results of a study on the organization and isomerization of the non-ionic and amphiphilic methyl 4-[(E)-2-[4-(nonyloxy)phenyl]diazen-1-yl]benzoate (LCA) in a 2D layer architecture of Langmuir and Langmuir-Blodgett (LB) films supported by spectroscopic studies on LCA chloroform solutions. Our investigation has shown a significantly different molecular organization of LCA depending on the ratio of trans and cis isomers in the monolayers. Taking advantage of a relatively low packing density and aggregation strength in the cis-LCA monolayer, we demonstrated the reversible isomerization in the LB film initially formed of LCA molecules in the cis form, while in the trans-LCA monolayer this effect was not observed. Our approach allows the formation of a switchable monolayer made of the amphiphilic LCA showing liquid crystalline properties without introducing an ionic group into the molecule structure, mixing with another compound or changing the subphase pH to provide free space for the molecules' isomerization.

Reduced calcification decreases photoprotective capability in the coccolithophorid Emiliania huxleyi.

PubMed

Xu, Kai; Gao, Kunshan

2012-07-01

Intracellular calcification of coccolithophores generates CO₂ and consumes additional energy for acquisition of calcium and bicarbonate ions; therefore, it may correlate with photoprotective processes by influencing the energetics. To address this hypothesis, a calcifying Emiliania huxleyi strain (CS-369) was grown semi-continuously at reduced (0.1 mM, LCa) and ambient Ca²⁺ concentrations (10 mM, HCa) for 150 d (>200 generations). The HCa-grown cells had higher photosynthetic and calcification rates and higher contents of Chl a and carotenoids compared with the naked (bearing no coccoliths) LCa-grown cells. When exposed to stressfull levels of photosynthetically active radiation (PAR), LCa-grown cells displayed lower photochemical yield and less efficient non-photochemical quenching (NPQ). When the LCa- or HCa-grown cells were inversely shifted to their counterpart medium, LCa to HCa transfer increased photosynthetic carbon fixation (P), calcification rate (C), the C/P ratio, NPQ and pigment contents, whereas those shifted from HCa to LCa exhibited the opposite effects. Increased NPQ, carotenoids and quantum yield were clearly linked with increased or sustained calcification in E. huxleyi. The calcification must have played a role in dissipating excessive energy or as an additional drainage of electrons absorbed by the photosynthetic antennae. This phenomenon was further supported by testing two non-calcifying strains, which showed insignificant changes in photosynthetic carbon fixation and NPQ when transferred to LCa conditions.

Distribution and significance of long-chain alkenones as salinity and temperature indicators in Spanish saline lake sediments

NASA Astrophysics Data System (ADS)

Pearson, Emma J.; Juggins, Steve; Farrimond, Paul

2008-08-01

We investigated relationships between sedimentary solvent-extractable long-chain alkenone (LCA) concentration and composition and environmental factors in a suite of endorheic lakes from inland Spain. LCAs were found in 14 of the 54 lakes examined, with concentrations comparable with those from previously published lacustrine settings. The composition of LCAs in our sites, however, contrast from the majority of those previously reported from lake environments; in our study the tri-unsaturated component is the most abundant component at most sites where LCAs are detected, and C 38:3 is the most abundant LCA in the majority of sites. LCA occurrence appears to be restricted to brackish-hypersaline sites and C 37 LCAs are absent above a salinity of ˜40 g L -1 suggesting a salinity control on LCA-producing organisms in these sites. Low concentrations of C 37 LCA components means U37k and U37k temperature indices are generally not applicable. Instead we find good relationships between C 38 components and (in particular mean autumn) temperature and the strongest LCA-temperature relationships are found when using a combination of all C 37 and C 38 compounds. We propose a new alkenone temperature index for lakes with elevated salinity and where the C 38 components dominate the LCA distributions. This is expressed as U3738k=0.0464×MAutAT-0.867 ( r2 = 0.80, n = 13). In this paper, we provide the first account of sedimentary LCA distributions from lakes in inland Spain, extending the range of environments within which these compounds have been found and highlighting their significance as indicators of both salinity and temperature in saline, endorheic lake environments. This has important implications for extending the potential role of LCAs as palaeoclimatic indicators in lacustrine environments.

Diagnostic application of clinical exome sequencing in Leber congenital amaurosis.

PubMed

Han, Jinu; Rim, John Hoon; Hwang, In Sik; Kim, Jieun; Shin, Saeam; Lee, Seung-Tae; Choi, Jong Rak

2017-01-01

Leber congenital amaurosis (LCA) is a hereditary retinal dystrophy with wide genetic heterogeneity. Next-generation sequencing (NGS) targeting multiple genes can be a good option for the diagnosis of LCA, and we tested a clinical exome panel in patients with LCA. A total of nine unrelated Korean patients with LCA were sequenced using the Illumina TruSight One panel, which targets 4,813 clinically associated genes, followed by confirmation using Sanger sequencing. Patients' clinical information and familial study results were obtained and used for comprehensive interpretation. In all nine patients, we identified pathogenic variations in LCA-associated genes: NMNAT1 (n=3), GUCY2D (n=2), RPGRIP1 (n=2), CRX (n=1), and CEP290 or SPATA7 . Six patients had one or two mutations in accordance with inheritance patterns, all consistent with clinical phenotypes. Two patients had only one pathogenic mutation in recessive genes ( NMNAT1 and RPGRIP1 ), and the clinical features were specific to disorders associated with those genes. Six patients were solved for genetic causes, and it remains unclear for three patients with the clinical exome panel. With subsequent targeted panel sequencing with 113 genes associated with infantile nystagmus syndrome, a likely pathogenic allele in CEP290 was detected in one patient. Interestingly, one pathogenic variant (p.Arg237Cys) in NMNAT1 was present in three patients, and it had a high allele frequency (0.24%) in the general Korean population, suggesting that NMNAT1 could be a major gene responsible for LCA in Koreans. We confirmed that a commercial clinical exome panel can be effectively used in the diagnosis of LCA. Careful interpretation and clinical correlation could promote the successful implementation of clinical exome panels in routine diagnoses of retinal dystrophies, including LCA.

Developments in life cycle assessment applied to evaluate the environmental performance of construction and demolition wastes.

PubMed

Bovea, M D; Powell, J C

2016-04-01

This paper provides a review of the literature that applies the life cycle assessment (LCA) methodology to the assessment of the environmental performance of the life cycle of construction and demolition waste (CDW) management systems. This article is focused on generating a general mapping of the literature and on identifying the best practices in compliance with LCA framework and proposing directions for future LCA studies in this field. The temporal evolution of the research in this field and the aim of the studies have grown in parallel with the legal framework related to waste and energy efficiency of buildings. Most studies have been published in Europe, followed by USA. Asia and Australia, being at an incipient application stage to the rest of the world. Topics related to "LCA of buildings, including their EoL" and "LCA of general CDW management strategies" are the most frequently analysed, followed by "LCA of EoL of construction elements" and "LCA of natural material vs recycled material". Regarding the strategies, recycling off-site and incineration, both combined with landfill for the rejected fractions, are the most commonly applied. Re-use or recycling on-site is the strategy least applied. The key aspect when LCA is applied to evaluate CDW management systems is the need to normalise which processes to include in the system boundary and the functional unit, the use of inventory data adapted to the context of the case study and the definition of a common set of appropriate impact assessment categories. Also, it is important to obtain results disaggregated by unit processes. This will allow the comparison between case studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

ATLAS (Automatic Tool for Local Assembly Structures) - A Comprehensive Infrastructure for Assembly, Annotation, and Genomic Binning of Metagenomic and Metaranscripomic Data

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

White, Richard A.; Brown, Joseph M.; Colby, Sean M.

ATLAS (Automatic Tool for Local Assembly Structures) is a comprehensive multiomics data analysis pipeline that is massively parallel and scalable. ATLAS contains a modular analysis pipeline for assembly, annotation, quantification and genome binning of metagenomics and metatranscriptomics data and a framework for reference metaproteomic database construction. ATLAS transforms raw sequence data into functional and taxonomic data at the microbial population level and provides genome-centric resolution through genome binning. ATLAS provides robust taxonomy based on majority voting of protein coding open reading frames rolled-up at the contig level using modified lowest common ancestor (LCA) analysis. ATLAS provides robust taxonomy based onmore » majority voting of protein coding open reading frames rolled-up at the contig level using modified lowest common ancestor (LCA) analysis. ATLAS is user-friendly, easy install through bioconda maintained as open-source on GitHub, and is implemented in Snakemake for modular customizable workflows.« less

Construction of special eye models for investigation of chromatic and higher-order aberrations of eyes.

PubMed

Zhai, Yi; Wang, Yan; Wang, Zhaoqi; Liu, Yongji; Zhang, Lin; He, Yuanqing; Chang, Shengjiang

2014-01-01

An achromatic element eliminating only longitudinal chromatic aberration (LCA) while maintaining transverse chromatic aberration (TCA) is established for the eye model, which involves the angle formed by the visual and optical axis. To investigate the impacts of higher-order aberrations on vision, the actual data of higher-order aberrations of human eyes with three typical levels are introduced into the eye model along visual axis. Moreover, three kinds of individual eye models are established to investigate the impacts of higher-order aberrations, chromatic aberration (LCA+TCA), LCA and TCA on vision under the photopic condition, respectively. Results show that for most human eyes, the impact of chromatic aberration on vision is much stronger than that of higher-order aberrations, and the impact of LCA in chromatic aberration dominates. The impact of TCA is approximately equal to that of normal level higher-order aberrations and it can be ignored when LCA exists.

Revision and extension of Eco-LCA metrics for sustainability assessment of the energy and chemical processes.

PubMed

Yang, Shiying; Yang, Siyu; Kraslawski, Andrzej; Qian, Yu

2013-12-17

Ecologically based life cycle assessment (Eco-LCA) is an appealing approach for the evaluation of resources utilization and environmental impacts of the process industries from an ecological scale. However, the aggregated metrics of Eco-LCA suffer from some drawbacks: the environmental impact metric has limited applicability; the resource utilization metric ignores indirect consumption; the renewability metric fails to address the quantitative distinction of resources availability; the productivity metric seems self-contradictory. In this paper, the existing Eco-LCA metrics are revised and extended for sustainability assessment of the energy and chemical processes. A new Eco-LCA metrics system is proposed, including four independent dimensions: environmental impact, resource utilization, resource availability, and economic effectiveness. An illustrative example of comparing assessment between a gas boiler and a solar boiler process provides insight into the features of the proposed approach.

Homogeneous Combinations of ASD-ADHD Traits and Their Cognitive and Behavioral Correlates in a Population-Based Sample.

PubMed

van der Meer, Jolanda M J; Lappenschaar, Martijn G A; Hartman, Catharina A; Greven, Corina U; Buitelaar, Jan K; Rommelse, Nanda N J

2017-07-01

Autism Spectrum Disorders (ASD) and ADHD are assumed to be the extreme manifestations of continuous heterogeneous traits that frequently co-occur. This study aims to identify subgroups of children with distinct ASD-ADHD trait profiles in the general population, using measures sensitive across both trait continua, and show how these subgroups differ in cognitive functioning. We examined 378 children (6-13 years) from a population-based sample. Latent class analyses (LCA) detected three concordant classes with low (10.1%), medium (54.2%), or high (13.2%) scores on both traits, and two discordant classes with more ADHD than ASD characteristics (ADHD > ASD, 18.3%) and vice versa (ASD > ADHD, 4.2%). Findings suggest that ASD and ADHD traits usually are strongly related in the unaffected population, and that a minority of children displays atypical discordant trait profiles characterized by differential visual-spatial functioning. This dissociation suggests that heterogeneity in ASD and ADHD is rooted in heterogeneity in the lower unaffected end of the distribution.

Hypothermic general cold adaptation induced by local cold acclimation.

PubMed

Savourey, G; Barnavol, B; Caravel, J P; Feuerstein, C; Bittel, J H

1996-01-01

To study relationships between local cold adaptation of the lower limbs and general cold adaptation, eight subjects were submitted both to a cold foot test (CFT, 5 degrees C water immersion, 5 min) and to a whole-body standard cold air test (SCAT, 1 degree C, 2 h, nude at rest) before and after a local cold acclimation (LCA) of the lower limbs effected by repeated cold water immersions. The LCA induced a local cold adaptation confirmed by higher skin temperatures of the lower limbs during CFT and a hypothermic insulative general cold adaptation (decreased rectal temperature and mean skin temperature P < 0.05) without a change either in metabolic heat production or in lower limb skin temperatures during SCAT after LCA. It was concluded that local cold adaptation was related to the habituation process confirmed by decreased plasma concentrations of noradrenaline (NA) during LCA (P < 0.05). However, the hypothermic insulative general cold adaptation was unrelated either to local cold adaptation or to the habituation process, because an increased NA during SCAT after LCA (P < 0.05) was observed but was rather related to a "T3 polar syndrome" occurring during LCA.

Leber congenital amaurosis associated with Chiari I malformation: Two cases and a review of the literature

PubMed Central

Petraglia, Anthony L.; Chengazi, Harris U.; Chung, Mina M.; Silberstein, Howard J.

2012-01-01

Objective: Leber congenital amaurosis (LCA) is a rare, clinically and genetically heterogeneous disorder characterized by severe loss of vision in the first year of life, affecting approximately 3000 people in the United States. Some LCA patients manifest developmental abnormalities of the central nervous system (CNS) and neuroradiological studies have revealed a variety of cerebral anomalies in association with LCA; however, Chiari I malformations (CMI) have never been described. Case Description: We report two sisters who were referred to the pediatric neurosurgery clinic for evaluation of CMI. The elder sister presented with convergence nystagmus from 3 months of age and magnetic resonance imaging (MRI) demonstrated evidence of significant CMI. Her younger sister began developing nystagmus at 4 months of age. Both had symptomatic progression and underwent suboccipital decompression. Both were subsequently diagnosed with LCA. Case specifics and imaging findings are presented. Conclusions: CMI have been found in association with several genetic syndromes, but not with LCA. These patients represent the first reported cases of CMI with LCA and suggest an additional potential CNS anomaly. The unique occurrence in siblings and the association with another inherited disorder are suggestive of a genetic basis for CMI. PMID:22347674

Challenge clusters facing LCA in environmental decision-making-what we can learn from biofuels.

PubMed

McManus, Marcelle C; Taylor, Caroline M; Mohr, Alison; Whittaker, Carly; Scown, Corinne D; Borrion, Aiduan Li; Glithero, Neryssa J; Yin, Yao

Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy's sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expert submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.

Challenge clusters facing LCA in environmental decision-making—what we can learn from biofuels

DOE PAGES

McManus, Marcelle C.; Taylor, Caroline M.; Mohr, Alison; ...

2015-08-07

Purpose: Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. Methods: The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expertmore » submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. Results and discussion: The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. Conclusions: The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.« less

Choices Regarding Thrombolysis Are Modified by the Way to Transfer the Messages.

PubMed

Gong, Jingjing; Zhang, Yan; Gao, Hongyan; Wei, Wei; Lv, Jing; Liu, Hongyun; Huang, Yonghua

2017-01-01

Although thrombolysis is the most effective medical treatment for acute ischemic stroke, many stroke patients eligible for thrombolysis miss this treatment as a result of delay or refusal by the patients and/or their proxies. To explore the influences of prognostic information for different intervals from stroke onset to the start of thrombolytic treatment (OTT) and other factors on the preferences of patients/proxies regarding thrombolytic therapy, a cross-sectional, discrete-choice experiment was performed between August 2013 and September 2014. A total of 613 Chinese inpatients or their immediate family members were consecutively recruited at the Department of Neurology. After random assignment to a negative-framing group or a positive-framing group, the subjects completed a series of surveys, including nine items about thrombolysis. Latent class analysis (LCA) was used to examine participants' preference paradigms for thrombolysis and to categorize the participants into different subgroups. Subsequently, regression analyses were conducted to explore predictors of categorization of the participants into each subgroup and to construct a thrombolytic decision-making model. LCA revealed an optimal 3-subgroup model including a consent to thrombolysis subgroup and objection to thrombolysis subgroups 1 and 2. Multiple regression analysis demonstrated that compared with assignment to the consent to thrombolysis subgroup, assignment to objection to thrombolysis subgroup 1 or 2 could be predicted by different factors. χ 2 tests indicated effects of framing and other factors on participants' choices regarding thrombolysis. Choices regarding thrombolysis were modified by not only prognostic information for different OTT intervals but also message framing, presentation format, and sociodemographic characteristics. To facilitate consent to thrombolysis, physicians should convey prognostic information to patients/proxies on the basis of patient OTT interval and should order the presentation of therapies according to the classification of patients/proxies. Individualized decision-making (IDM) might be an optimal strategy to increase the selection of thrombolysis, which providing important reference points for IDM in other clinical domains.

Choices Regarding Thrombolysis Are Modified by the Way to Transfer the Messages

PubMed Central

Gong, Jingjing; Zhang, Yan; Gao, Hongyan; Wei, Wei; Lv, Jing; Liu, Hongyun; Huang, Yonghua

2017-01-01

Although thrombolysis is the most effective medical treatment for acute ischemic stroke, many stroke patients eligible for thrombolysis miss this treatment as a result of delay or refusal by the patients and/or their proxies. To explore the influences of prognostic information for different intervals from stroke onset to the start of thrombolytic treatment (OTT) and other factors on the preferences of patients/proxies regarding thrombolytic therapy, a cross-sectional, discrete-choice experiment was performed between August 2013 and September 2014. A total of 613 Chinese inpatients or their immediate family members were consecutively recruited at the Department of Neurology. After random assignment to a negative-framing group or a positive-framing group, the subjects completed a series of surveys, including nine items about thrombolysis. Latent class analysis (LCA) was used to examine participants’ preference paradigms for thrombolysis and to categorize the participants into different subgroups. Subsequently, regression analyses were conducted to explore predictors of categorization of the participants into each subgroup and to construct a thrombolytic decision-making model. LCA revealed an optimal 3-subgroup model including a consent to thrombolysis subgroup and objection to thrombolysis subgroups 1 and 2. Multiple regression analysis demonstrated that compared with assignment to the consent to thrombolysis subgroup, assignment to objection to thrombolysis subgroup 1 or 2 could be predicted by different factors. χ2 tests indicated effects of framing and other factors on participants’ choices regarding thrombolysis. Choices regarding thrombolysis were modified by not only prognostic information for different OTT intervals but also message framing, presentation format, and sociodemographic characteristics. To facilitate consent to thrombolysis, physicians should convey prognostic information to patients/proxies on the basis of patient OTT interval and should order the presentation of therapies according to the classification of patients/proxies. Individualized decision-making (IDM) might be an optimal strategy to increase the selection of thrombolysis, which providing important reference points for IDM in other clinical domains. PMID:29167657

An Environmental Impact Analysis of Semi-Mechanical Extraction Process of Sago Starch: Life Cycle Assessment (LCA) Perspective

NASA Astrophysics Data System (ADS)

Yusuf, M. A.; Romli, M.; Suprihatin; Wiloso, E. I.

2018-05-01

Industrial activities use material, energy and water resources and generate greenhouse gas (GHG). Currently, various regulations require industry to measure and quantify the emissions generated from its process activity. LCA is a method that can be used to analyze and report the environmental impact of an activity that uses resources and generates waste by an industrial activity. In this work, LCA is used to determine the environmental impact of a semi-mechanical extraction process of sago industry. The data was collected through the sago industry in Cimahpar, Bogor. The extraction of sago starch consists of stem cutting, rasping, mixing, filtration, starch sedimentation, washing, and drying. The scope of LCA study covers the harvesting of sago stem, transportation to extraction site, and the starch extraction process. With the assumption that the average transportation distance of sago stem to extraction site is 200 km, the GHG emission is estimated to be 325 kg CO2 eq / ton of sundried sago starch. This figure is lower than that reported for maize starch (1120 kg CO2 eq), potato starch (2232 kg CO2 eq) and cassava starch (4310 kg CO2 eq). This is most likely due to the uncounted impact from the use of electrical energy on the extraction process, which is currently being conducted. A follow-up study is also underway to formulate several process improvement scenarios to derive the design of sago starch processing that generates the minimum emissions.

Towards a Computational Comparative Neuroprimatology: Framing the language-ready brain.

PubMed

Arbib, Michael A

2016-03-01

We make the case for developing a Computational Comparative Neuroprimatology to inform the analysis of the function and evolution of the human brain. First, we update the mirror system hypothesis on the evolution of the language-ready brain by (i) modeling action and action recognition and opportunistic scheduling of macaque brains to hypothesize the nature of the last common ancestor of macaque and human (LCA-m); and then we (ii) introduce dynamic brain modeling to show how apes could acquire gesture through ontogenetic ritualization, hypothesizing the nature of evolution from LCA-m to the last common ancestor of chimpanzee and human (LCA-c). We then (iii) hypothesize the role of imitation, pantomime, protosign and protospeech in biological and cultural evolution from LCA-c to Homo sapiens with a language-ready brain. Second, we suggest how cultural evolution in Homo sapiens led from protolanguages to full languages with grammar and compositional semantics. Third, we assess the similarities and differences between the dorsal and ventral streams in audition and vision as the basis for presenting and comparing two models of language processing in the human brain: A model of (i) the auditory dorsal and ventral streams in sentence comprehension; and (ii) the visual dorsal and ventral streams in defining "what language is about" in both production and perception of utterances related to visual scenes provide the basis for (iii) a first step towards a synthesis and a look at challenges for further research. Copyright © 2015 Elsevier B.V. All rights reserved.

Two-scale evaluation of remediation technologies for a contaminated site by applying economic input-output life cycle assessment: risk-cost, risk-energy consumption and risk-CO2 emission.

PubMed

Inoue, Yasushi; Katayama, Arata

2011-09-15

A two-scale evaluation concept of remediation technologies for a contaminated site was expanded by introducing life cycle costing (LCC) and economic input-output life cycle assessment (EIO-LCA). The expanded evaluation index, the rescue number for soil (RN(SOIL)) with LCC and EIO-LCA, comprises two scales, such as risk-cost, risk-energy consumption or risk-CO(2) emission of a remediation. The effectiveness of RN(SOIL) with LCC and EIO-LCA was examined in a typical contamination and remediation scenario in which dieldrin contaminated an agricultural field. Remediation was simulated using four technologies: disposal, high temperature thermal desorption, biopile and landfarming. Energy consumption and CO(2) emission were determined from a life cycle inventory analysis using monetary-based intensity based on an input-output table. The values of RN(SOIL) based on risk-cost, risk-energy consumption and risk-CO(2) emission were calculated, and then rankings of the candidates were compiled according to RN(SOIL) values. A comparison between three rankings showed the different ranking orders. The existence of differences in ranking order indicates that the scales would not have reciprocal compatibility for two-scale evaluation and that each scale should be used independently. The RN(SOIL) with LCA will be helpful in selecting a technology, provided an appropriate scale is determined. Copyright © 2011 Elsevier B.V. All rights reserved.

Towards a Computational Comparative Neuroprimatology: Framing the language-ready brain

NASA Astrophysics Data System (ADS)

Arbib, Michael A.

2016-03-01

We make the case for developing a Computational Comparative Neuroprimatology to inform the analysis of the function and evolution of the human brain. First, we update the mirror system hypothesis on the evolution of the language-ready brain by (i) modeling action and action recognition and opportunistic scheduling of macaque brains to hypothesize the nature of the last common ancestor of macaque and human (LCA-m); and then we (ii) introduce dynamic brain modeling to show how apes could acquire gesture through ontogenetic ritualization, hypothesizing the nature of evolution from LCA-m to the last common ancestor of chimpanzee and human (LCA-c). We then (iii) hypothesize the role of imitation, pantomime, protosign and protospeech in biological and cultural evolution from LCA-c to Homo sapiens with a language-ready brain. Second, we suggest how cultural evolution in Homo sapiens led from protolanguages to full languages with grammar and compositional semantics. Third, we assess the similarities and differences between the dorsal and ventral streams in audition and vision as the basis for presenting and comparing two models of language processing in the human brain: A model of (i) the auditory dorsal and ventral streams in sentence comprehension; and (ii) the visual dorsal and ventral streams in defining ;what language is about; in both production and perception of utterances related to visual scenes provide the basis for (iii) a first step towards a synthesis and a look at challenges for further research.

Developing Anticipatory Life Cycle Assessment Tools to Support Responsible Innovation

NASA Astrophysics Data System (ADS)

Wender, Benjamin

Several prominent research strategy organizations recommend applying life cycle assessment (LCA) early in the development of emerging technologies. For example, the US Environmental Protection Agency, the National Research Council, the Department of Energy, and the National Nanotechnology Initiative identify the potential for LCA to inform research and development (R&D) of photovoltaics and products containing engineered nanomaterials (ENMs). In this capacity, application of LCA to emerging technologies may contribute to the growing movement for responsible research and innovation (RRI). However, existing LCA practices are largely retrospective and ill-suited to support the objectives of RRI. For example, barriers related to data availability, rapid technology change, and isolation of environmental from technical research inhibit application of LCA to developing technologies. This dissertation focuses on development of anticipatory LCA tools that incorporate elements of technology forecasting, provide robust explorations of uncertainty, and engage diverse innovation actors in overcoming retrospective approaches to environmental assessment and improvement of emerging technologies. Chapter one contextualizes current LCA practices within the growing literature articulating RRI and identifies the optimal place in the stage gate innovation model to apply LCA. Chapter one concludes with a call to develop anticipatory LCA---building on the theory of anticipatory governance---as a series of methodological improvements that seek to align LCA practices with the objectives of RRI. Chapter two provides a framework for anticipatory LCA, identifies where research from multiple disciplines informs LCA practice, and builds off the recommendations presented in the preceding chapter. Chapter two focuses on crystalline and thin film photovoltaics (PV) to illustrate the novel framework, in part because PV is an environmentally motivated technology undergoing extensive R&D efforts and rapid increases in scale of deployment. The chapter concludes with a series of research recommendations that seek to direct PV research agenda towards pathways with the greatest potential for environmental improvement. Similar to PV, engineered nanomaterials (ENMs) are an emerging technology with numerous potential applications, are the subject of active R&D efforts, and are characterized by high uncertainty regarding potential environmental implications. Chapter three introduces a Monte Carlo impact assessment tool based on the toxicity impact assessment model USEtox and demonstrates stochastic characterization factor (CF) development to prioritize risk research with the greatest potential to improve certainty in CFs. The case study explores a hypothetical decision in which personal care product developers are interested in replacing the conventional antioxidant niacinamide with the novel ENM C 60, but face high data uncertainty, are unsure regarding potential ecotoxicity impacts associated with this substitution, and do not know what future risk-relevant experiments to invest in that most efficiently improve certainty in the comparison. Results suggest experiments that elucidate C60 partitioning to suspended solids should be prioritized over parameters with little influence on results. This dissertation demonstrates a novel anticipatory approach to exploration of uncertainty in environmental models that can create new, actionable knowledge with potential to guide future research and development decisions.

Tuberculosis infection among young nursing trainees in South India.

PubMed

Christopher, Devasahayam J; Daley, Peter; Armstrong, Lois; James, Prince; Gupta, Richa; Premkumar, Beulah; Michael, Joy Sarojini; Radha, Vedha; Zwerling, Alice; Schiller, Ian; Dendukuri, Nandini; Pai, Madhukar

2010-04-29

Among healthcare workers in developing countries, nurses spend a large amount of time in direct contact with tuberculosis (TB) patients, and are at high risk for acquisition of TB infection and disease. To better understand the epidemiology of nosocomial TB among nurses, we recruited a cohort of young nursing trainees at Christian Medical College, a large, tertiary medical school hospital in Southern India. Among 535 nursing students enrolled in 2007, 468 gave consent to participate, and 436 underwent two-step tuberculin skin testing (TST). A majority (95%) were females, and almost 80% were under 22 years of age. Detailed TB exposure information was obtained using interviews and clinical log books. Prevalence of latent TB infection (LTBI) was estimated using Bayesian latent class analyses (LCA). Logistic regression analyses were done to determine the association between LTBI prevalence and TB exposure and risk factors. 219 of 436 students (50.2%, 95% CI: 45.4-55.0) were TST positive using the 10 mm or greater cut-off. Based on the LCA, the prevalence of LTBI was 47.8% (95% credible interval 17.8% to 65.6%). In the multivariate analysis, TST positivity was strongly associated with time spent in health care, after adjusting for age at entry into healthcare. Our study showed a high prevalence of LTBI even in young nursing trainees. With the recent TB infection control (TBIC) policy guidance from the World Health Organization as the reference, Indian healthcare providers and the Indian Revised National TB Control Programme will need to implement TBIC interventions, and enhance capacity for TBIC at the country level. Young trainees and nurses, in particular, will need to be targeted for TBIC interventions.

School-readiness profiles of children with language impairment: linkages to home and classroom experiences.

PubMed

Pentimonti, Jill M; Justice, Laura M; Kaderavek, Joan N

2014-01-01

This study represents an effort to advance our understanding of the nature of school readiness among children with language impairment (LI), a population of children acknowledged to be at risk of poor academic achievement. The academic, social-emotional, and behavioural competencies with which children arrive at kindergarten affect the nature of their future educational experiences, and their overall academic achievement. To examine whether there are reliable profiles that characterize children with LI just prior to kindergarten entrance, and the extent to which profile membership is associated with characteristics of children's homes and preschool experiences. Questions addressed were twofold: (1) To what extent are there reliable profiles of children with LI with respect to their school readiness? (2) To what extent is children's profile membership associated with characteristics of their homes and preschool classrooms? Participants were 136 children with LI from early childhood special education classrooms. We utilized latent class analysis (LCA) to classify individuals into profiles based on individual responses on school readiness measures. We then used multilevel hierarchical generalized linear models to examine the relations between profile membership and children's home/classroom experiences. LCA analyses revealed that a four-profile solution was the most appropriate fit for the data and that classroom experiences were predictive of these profiles, such that children in classrooms with more instructional/emotional support were more likely to be placed in profiles characterized by higher school readiness skills. These results suggest that the school readiness profiles of young children with LI are associated with the quality of children's classroom experiences, and that high-quality classroom experiences can be influential for ensuring that young children with LI arrive in kindergarten ready to learn. © 2014 Royal College of Speech and Language Therapists.

Recommend, but also Discuss: Different Patterns of Physician-Perceived Barriers to Discussing HPV Vaccination and Their Association with Vaccine Administration in 11-12 Year-Old Girls.

PubMed

Kulczycki, Andrzej; Qu, Haiyan; Shewchuk, Richard

2016-12-01

Objectives We examined variation in primary care physicians' (PCPs') perceptions of barriers to physician-initiated discussion of HPV vaccination, and how this is associated with the rates at which they discuss, initiate and continue to administer vaccination with 11-12 year-old girls. Methods We surveyed 301 PCPs using systematic random sampling. PCP variation in perceived barriers to discussing HPV vaccination was modeled using latent class analysis (LCA). The distinct PCP groups identified were compared with each other using three iterative logistic regression models to predict the likelihood of initiating vaccine discussion and the reported percentages of 11-12 year-old patients who initiated HPV vaccination and received follow-up shots. Results LCA revealed three groups of PCPs who perceived major, moderately significant and relatively minor barriers (17.9, 41.9 and 40.2 % of respondents, respectively). Pediatricians, PCPs who were female, had minority racial/ethnic status and who perceived only minor barriers had significantly higher odds of initiating discussion. PCPs were more likely to initiate HPV vaccination if they had initiated discussion and perceived minor or moderate communication barriers. Increased likelihood to administer follow-up HPV vaccine was associated with having initiated discussion, perceiving only minor barriers and working outside Deep South states, but not with having initiated vaccination. Conclusions for Practice PCPs who discuss HPV vaccination with girls aged 11-12 and their mothers are more likely to start and sustain vaccine administration. However, different PCPs perceive barriers to discussion in different ways. Interventions tailored to different groups of PCPs should assist them in overcoming barriers to discussing their recommendations when necessary.

Patterns and associates of cognitive function, psychosocial wellbeing and health in the Lothian Birth Cohort 1936

PubMed Central

2014-01-01

Background Cognitive function, psychosocial wellbeing and health are important domains of function. Consistencies and inconsistencies in patterns of wellbeing across these domains may be informative about wellbeing in old age and the ways it is manifested amongst individuals. In this study we investigated whether there were groups of individuals with different profiles of scores across these domains. We also aimed to identify characteristics of any evident groups by comparing them on variables that were not used in identifying the groups. Methods The sample was the Lothian Birth Cohort 1936, which included 1091 participants born in 1936. They are a community-dwelling, narrow-age-range sample of 70-year-olds. Most had taken part in the Scottish Mental Survey 1947 at an average age of 11, making available a measure of childhood intelligence. We used latent class analysis (LCA) to explore possible profiles using 9 variables indicating cognitive functioning, psychosocial wellbeing and health status. Demographic, personality, and lifestyle variables – none of which were used in the LCA – were used to characterize the resulting profile groups. Results We accepted a 3-group solution, which we labeled High Wellbeing (65.3%), Low Cognition (20.3%), and Low Bio-Psychosocial (14.5%). Notably, the High Wellbeing group had significantly higher childhood IQ, lower Neuroticism scores, and a lower percentage of current smokers than the other 2 groups. Conclusion The majority of individuals were functioning generally well; however, there was evidence of the presence of groups with different profiles, which may be explained in part in terms of cognitive ability differences. Results suggested that higher life-long intelligence, personality traits associated with less mental distress, and basic health practices such as avoiding smoking are important associates of wellbeing in old age. PMID:24754844

The association between social support and cognitive function in Mexican adults aged 50 and older.

PubMed

Zamora-Macorra, Mireya; de Castro, Elga Filipa Amorin; Ávila-Funes, José Alberto; Manrique-Espinoza, Betty Soledad; López-Ridaura, Ruy; Sosa-Ortiz, Ana Luisa; Shields, Pamela L; Del Campo, Daniel Samano Martin

Social support networks are crucial for the health of older adults; however, personal characteristics and time of life may diminish the protective effect of social support. to determine if the presence of social support networks were associated with cognitive impairment among Mexican adults aged 50 or older and if this relationship was different based on age. This study analyzed data from the National Representation Survey performed in Mexico, Study on Global Ageing (SAGE) wave 1. Cognitive function was evaluated by a standardized test, social support was evaluated through latent class analysis (LCA). The LCA was run to obtain three subgroups of different Social Support Levels (SSL): low, medium, and high. Logistic regression models, stratified by age, were performed to analyze the association between SSL and cognitive function. For respondents ages 71-80 y/o, there was an inverse relationship with cognitive impairment for those with medium (OR 0.23, p=0.020) and high (OR 0.07, p=0.000) SSL in comparison with low SSL. While social support helped to improve cognitive function in older adults aged 71-80, this same association was not observed in adults of other ages. Those younger than 70 y/o may not need such a strong support network as a result of being more self-sufficient. After 80, social networks were not enough to help diminish the negative impact of cognitive impairment. Social support could improve the cognitive function of adults ages 71 and 80; suggesting there could be a window of opportunity to improve cognitive functioning for this group. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Water-Energy Nexus: the case of biogas production from energy crops evaluated by Water Footprint and LCA methods

NASA Astrophysics Data System (ADS)

Pacetti, Tommaso; Caporali, Enrica; Federici, Giorgio

2015-04-01

This study analyzes the production of biogas from aerobic digestion of energy crops. The production of biogas is an important case study because its spread, similar to other sources of bioenergy, creates questions about the environmental effects, the competition in the food market as well as the progressive change of land use. In particular is hereby analyzed the nexus between bioenergy production and water, which plays a key role because water resources are often the limiting factor in energy production from energy crops. The environmental performances of biogas production were analyzed through Water Footprint (WF) and Life cycle assessment (LCA): the integration of LCA and WF represents an attempt of taking advantage of their complementary strengths in environmental assessment, trying to give a comprehensive analysis of bioenergy production sustainability. Eighteen scenarios were considered, trying to figure out the performances of different combinations of locations (north, center, south Italy), crops (maize, sorghum, wheat) and treatments (anaerobic digestion with water dilution or manure co-digestion). WF assessment shows that cultivation phase is the most impacting on water resource use along the entire system life cycle. In particular, water requirements for crop growth shows that sorghum is the more water saver crop (in terms of consumptive water use to produce the amount of crop needed to produce 1 GJ of biogas energy content). Moreover WF investigates the kind of water use and shows that wheat, despite being the most intensive water user, exploits more green water than the other crops.WF was evaluated with respect to water stress indicators for the Italian territory, underlining the higher criticalities associated with water use in southern Italy and identifying consumptive blue water use, in this area, as the main hotspot. Therefore biogas production from energy crops in southern Italy is unsustainable from a water management perspective. At a basin scale, WF results obtained for central Italy were compared with local water availability (Merse river basin), pinpointing the time dependence of the sustainability. This analysis highlights that wheat, even if more water intensive than other crops, has a WF that not burdens the driest period as maize and sorghum does, underlying importance of assessing the temporal distribution of water use. Further, WF was combined with LCA. First WF results were used as input for LCA inventory, and then some indicators of the selected impact assessment method were analyzed to obtain additional information mainly on water resource quality. The overall results show that biogas production from energy crops has in general negative impacts (i.e. beneficial environmental performances), due to the savings associated with avoided conventional energy production, for all the indicators except water depletion, fresh water ecotoxicity and marine ecotoxicity. WF and LCA results show the benefit of coupling the two methods. Since WF focuses on the water use and the LCA focus on an extended range of environmental loads, creating synergies between these two approaches can help having a comprehensive assessment and a better insight in the Nexus.

Coping with Stress in Deprived Urban Neighborhoods: What Is the Role of Green Space According to Life Stage?

PubMed

Roe, Jenny J; Aspinall, Peter A; Ward Thompson, Catharine

2017-01-01

This study follows previous research showing how green space quantity and contact with nature (via access to gardens/allotments) helps mitigate stress in people living in deprived urban environments (Ward Thompson et al., 2016). However, little is known about how these environments aid stress mitigation nor how stress levels vary in a population experiencing higher than average stress. This study used Latent Class Analysis (LCA) to, first, identify latent health clusters in the same population ( n = 406) and, second, to relate health cluster membership to variables of interest, including four hypothetical stress coping scenarios. Results showed a three-cluster model best fit the data, with membership to health clusters differentiated by age, perceived stress, general health, and subjective well-being. The clusters were labeled by the primary health outcome (i.e., perceived stress) and age group (1) Low-stress Youth characterized by ages 16-24; (2) Low-stress Seniors characterized by ages 65+ and (3) High-stress Mid-Age characterized by ages 25-44. Next, LCA identified that health membership was significantly related to four hypothetical stress coping scenarios set in people's current residential context: " staying at home " and three scenarios set outwith the home, " seeking peace and quiet," "going for a walk " or " seeking company. " Stress coping in Low stress Youth is characterized by " seeking company " and " going for a walk "; stress coping in Low-stress Seniors and High stress Mid-Age is characterized by " staying at home. " Finally, LCA identified significant relationships between health cluster membership and a range of demographic, other individual and environmental variables including access to, use of and perceptions of local green space. Our study found that the opportunities in the immediate neighborhood for stress reduction vary by age. Stress coping in youth is likely supported by being social and keeping physically active outdoors, including local green space visits. By contrast, local green space appears not to support stress regulation in young-middle aged and older adults, who choose to stay at home. We conclude that it is important to understand the complexities of stress management and the opportunities offered by local green space for stress mitigation by age and other demographic variables, such as gender.

Coping with Stress in Deprived Urban Neighborhoods: What Is the Role of Green Space According to Life Stage?

PubMed Central

Roe, Jenny J.; Aspinall, Peter A.; Ward Thompson, Catharine

2017-01-01

This study follows previous research showing how green space quantity and contact with nature (via access to gardens/allotments) helps mitigate stress in people living in deprived urban environments (Ward Thompson et al., 2016). However, little is known about how these environments aid stress mitigation nor how stress levels vary in a population experiencing higher than average stress. This study used Latent Class Analysis (LCA) to, first, identify latent health clusters in the same population (n = 406) and, second, to relate health cluster membership to variables of interest, including four hypothetical stress coping scenarios. Results showed a three-cluster model best fit the data, with membership to health clusters differentiated by age, perceived stress, general health, and subjective well-being. The clusters were labeled by the primary health outcome (i.e., perceived stress) and age group (1) Low-stress Youth characterized by ages 16–24; (2) Low-stress Seniors characterized by ages 65+ and (3) High-stress Mid-Age characterized by ages 25–44. Next, LCA identified that health membership was significantly related to four hypothetical stress coping scenarios set in people's current residential context: “staying at home” and three scenarios set outwith the home, “seeking peace and quiet,” “going for a walk” or “seeking company.” Stress coping in Low stress Youth is characterized by “seeking company” and “going for a walk”; stress coping in Low-stress Seniors and High stress Mid-Age is characterized by “staying at home.” Finally, LCA identified significant relationships between health cluster membership and a range of demographic, other individual and environmental variables including access to, use of and perceptions of local green space. Our study found that the opportunities in the immediate neighborhood for stress reduction vary by age. Stress coping in youth is likely supported by being social and keeping physically active outdoors, including local green space visits. By contrast, local green space appears not to support stress regulation in young-middle aged and older adults, who choose to stay at home. We conclude that it is important to understand the complexities of stress management and the opportunities offered by local green space for stress mitigation by age and other demographic variables, such as gender. PMID:29093689

Culturing of the first 37:4 predominant lacustrine haptophyte: Geochemical, biochemical, and genetic implications

NASA Astrophysics Data System (ADS)

Toney, Jaime L.; Theroux, Susanna; Andersen, Robert A.; Coleman, Annette; Amaral-Zettler, Linda; Huang, Yongsong

2012-02-01

Long chain alkenones (LCAs) are potential biomarkers for quantitative paleotemperature reconstructions from lacustrine environments. However, progress in this area has been hindered, because the conditions necessary for the growth of haptophytes responsible for alkenone distributions in lake sediments: the predominance of C 37:4 LCA are not known. Here we report the first enrichment culturing of a novel haptophyte phylotype (Hap-A) from Lake George, ND that produces predominantly C 37:4-LCA. Hap-A was enriched from its resting phase collected from deep sediments rather than from water column samples. In contrast, enrichments from near surface water yielded a different haptophyte phylotype (Hap-B), closely related to Chrysotila lamellosa and Pseudoisochrysis paradoxa, which does not display C 37:4-LCA predominance (similar enrichments have been reported previously). The LCA profile in sediments resembles that of enrichments containing Hap-A, suggesting that Hap-A is the dominant alkenone producer of the sedimentary LCAs. In enrichments, increased lighting appeared to be crucial for triggering alkenone production. Both U37K and U38K indices show a promising, positive relationship with temperature for Hap-A in enrichments, but the offset from the environmental calibration suggests that other factors (e.g., the growth stage or nutrients) may influence the absolute U37K value. Based on 18S rRNA gene analyses, several lakes from the Northern Great Plains, as well as Pyramid Lake, NV and Tso Ur, Tibetan Plateau, China contain the same two haptophyte phylotypes. Analysis of surface sediment from the Great Plains lakes show the Hap-A-type LCA distribution, whereas Pyramid and Tso Ur show the Hap-B type distribution. Waters of the Great Plain lakes are dominated by sulfate ions, whereas those Pyramid and Tso Ur are dominated by carbonate ions, suggesting that the sulfate to carbonate ratio may be a determining factor for the dominance of the Hap-A and Hap-B phylotypes in natural settings.

Water System Adaptation To Hydrological Changes: Module 14, Life Cycle Analysis (LCA) and Prioritization Tools in Water System Adaptation

EPA Science Inventory

This course will introduce students to the fundamental principles of water system adaptation to hydrological changes, with emphasis on data analysis and interpretation, technical planning, and computational modeling. Starting with real-world scenarios and adaptation needs, the co...

Patterns of youth tobacco and polytobacco usage: The shift to alternative tobacco products.

PubMed

Harrell, Paul T; Naqvi, Syeda Mahrukh H; Plunk, Andrew D; Ji, Ming; Martins, Silvia S

2017-11-01

Despite significant declines in youth cigarette smoking, overall tobacco usage remains over 20% as non-cigarette tobacco product usage is increasingly common and polytobacco use (using 1+ tobacco product) remains steady. The present study was designed to identify patterns of youth tobacco use and examine associations with sociodemographic characteristics and tobacco dependence. The current analysis uses Latent Class Analysis (LCA) to examine the 6,958 tobacco users (n = 2,738 female) in the National Youth Tobacco Survey (2012 and 2013). We used as indicators past month use of tobacco products (cigarettes, cigars, smokeless tobacco, e-cigarettes, hookah, snus, pipes, bidis, and kreteks) and regressed resulting classes on sociodemographic characteristics and tobacco dependence. Nine classes emerged: cigarette smokers (33.4% of sample, also included small probabilities for use of cigars and e-cigarettes), cigar smokers (16.8%, nearly exclusive), smokeless tobacco users (12.3%, also included small probabilities for cigarettes, cigars, snus), hookah smokers (11.8%), tobacco smokers/chewers (10.7%, variety of primarily traditional tobacco products), tobacco/hookah smokers (7.2%), tobacco/snus/e-cig users (3.3%), e-cigarette users (2.9%,), and polytobacco users (1.7%, high probabilities for all products). Compared to cigarette smokers, tobacco/hookah smokers and hookah smokers were more likely to report Hispanic ethnicity. Polytobacco users were more likely to report dependence (AOR:2.77, 95% CI:[1.49-5.18]), whereas e-cigarette users were less likely (AOR:0.49, 95% CI:[0.24-0.97]). Findings are consistent with other research demonstrating shifts in adolescent tobacco product usage towards non-cigarette tobacco products. Continuous monitoring of these patterns is needed to help predict if this shift will ultimately result in improved public health.

Life Cycle Assessment and Cost Analysis of Water and ...

EPA Pesticide Factsheets

changes in drinking and wastewater infrastructure need to incorporate a holistic view of the water service sustainability tradeoffs and potential benefits when considering shifts towards new treatment technology, decentralized systems, energy recovery and reuse of treated wastewater. The main goal of this study is to determine the influence of scale on the energy and cost performance of different transitional membrane bioreactors (MBR) in decentralized wastewater treatment (WWT) systems by performing a life cycle assessment (LCA) and cost analysis. LCA is a tool used to quantify sustainability-related metrics from a systems perspective. The study calculates the environmental and cost profiles of both aerobic MBRs (AeMBR) and anaerobic MBRs (AnMBR), which not only recover energy from waste, but also produce recycled water that can displace potable water for uses such as irrigation and toilet flushing. MBRs represent an intriguing technology to provide decentralized WWT services while maximizing resource recovery. A number of scenarios for these WWT technologies are investigated for different scale systems serving various population density and land area combinations to explore the ideal application potentials. MBR systems are examined from 0.05 million gallons per day (MGD) to 10 MGD and serve land use types from high density urban (100,000 people per square mile) to semi-rural single family (2,000 people per square mile). The LCA and cost model was built with ex

Policy implications of allocation methods in the life cycle analysis of integrated corn and corn stover ethanol production

DOE PAGES

Canter, Christina E.; Dunn, Jennifer B.; Han, Jeongwoo; ...

2015-08-18

Here, a biorefinery may produce multiple fuels from more than one feedstock. The ability of these fuels to qualify as one of the four types of biofuels under the US Renewable Fuel Standard and to achieve a low carbon intensity score under California’s Low Carbon Fuel Standard can be strongly influenced by the approach taken to their life cycle analysis (LCA). For example, in facilities that may co-produce corn grain and corn stover ethanol, the ethanol production processes can share the combined heat and power (CHP) that is produced from the lignin and liquid residues from stover ethanol production. Wemore » examine different LCA approaches to corn grain and stover ethanol production considering different approaches to CHP treatment. In the baseline scenario, CHP meets the energy demands of stover ethanol production first, with additional heat and electricity generated sent to grain ethanol production. The resulting greenhouse gas (GHG) emissions for grain and stover ethanol are 57 and 25 g-CO 2eq/MJ, respectively, corresponding to a 40 and 74% reduction compared to the GHG emissions of gasoline. We illustrate that emissions depend on allocation of burdens of CHP production and corn farming, along with the facility capacities. Co-product handling techniques can strongly influence LCA results and should therefore be transparently documented.« less

Policy implications of allocation methods in the life cycle analysis of integrated corn and corn stover ethanol production

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

Canter, Christina E.; Dunn, Jennifer B.; Han, Jeongwoo

Here, a biorefinery may produce multiple fuels from more than one feedstock. The ability of these fuels to qualify as one of the four types of biofuels under the US Renewable Fuel Standard and to achieve a low carbon intensity score under California’s Low Carbon Fuel Standard can be strongly influenced by the approach taken to their life cycle analysis (LCA). For example, in facilities that may co-produce corn grain and corn stover ethanol, the ethanol production processes can share the combined heat and power (CHP) that is produced from the lignin and liquid residues from stover ethanol production. Wemore » examine different LCA approaches to corn grain and stover ethanol production considering different approaches to CHP treatment. In the baseline scenario, CHP meets the energy demands of stover ethanol production first, with additional heat and electricity generated sent to grain ethanol production. The resulting greenhouse gas (GHG) emissions for grain and stover ethanol are 57 and 25 g-CO 2eq/MJ, respectively, corresponding to a 40 and 74% reduction compared to the GHG emissions of gasoline. We illustrate that emissions depend on allocation of burdens of CHP production and corn farming, along with the facility capacities. Co-product handling techniques can strongly influence LCA results and should therefore be transparently documented.« less

Optimal sparse approximation with integrate and fire neurons.

PubMed

Shapero, Samuel; Zhu, Mengchen; Hasler, Jennifer; Rozell, Christopher

2014-08-01

Sparse approximation is a hypothesized coding strategy where a population of sensory neurons (e.g. V1) encodes a stimulus using as few active neurons as possible. We present the Spiking LCA (locally competitive algorithm), a rate encoded Spiking Neural Network (SNN) of integrate and fire neurons that calculate sparse approximations. The Spiking LCA is designed to be equivalent to the nonspiking LCA, an analog dynamical system that converges on a ℓ(1)-norm sparse approximations exponentially. We show that the firing rate of the Spiking LCA converges on the same solution as the analog LCA, with an error inversely proportional to the sampling time. We simulate in NEURON a network of 128 neuron pairs that encode 8 × 8 pixel image patches, demonstrating that the network converges to nearly optimal encodings within 20 ms of biological time. We also show that when using more biophysically realistic parameters in the neurons, the gain function encourages additional ℓ(0)-norm sparsity in the encoding, relative both to ideal neurons and digital solvers.

Neuromuscular control of fundamental frequency and glottal posture at phonation onset

PubMed Central

Chhetri, Dinesh K.; Neubauer, Juergen; Berry, David A.

2012-01-01

The laryngeal neuromuscular mechanisms for modulating glottal posture and fundamental frequency are of interest in understanding normal laryngeal physiology and treating vocal pathology. The intrinsic laryngeal muscles in an in vivo canine model were electrically activated in a graded fashion to investigate their effects on onset frequency, phonation onset pressure, vocal fold strain, and glottal distance at the vocal processes. Muscle activation plots for these laryngeal parameters were evaluated for the interaction of following pairs of muscle activation conditions: (1) cricothyroid (CT) versus all laryngeal adductors (TA/LCA/IA), (2) CT versus LCA/IA, (3) CT versus thyroarytenoid (TA) and, (4) TA versus LCA/IA (LCA: lateral cricoarytenoid muscle, IA: interarytenoid). Increases in onset frequency and strain were primarily affected by CT activation. Onset pressure correlated with activation of all adductors in activation condition 1, but primarily with CT activation in conditions 2 and 3. TA and CT were antagonistic for strain. LCA/IA activation primarily closed the cartilaginous glottis while TA activation closed the mid-membranous glottis. PMID:22352513

Potential for Integrating Diffusion of Innovation Principles into Life Cycle Assessment of Emerging Technologies.

PubMed

Sharp, Benjamin E; Miller, Shelie A

2016-03-15

Life cycle assessment (LCA) measures cradle-to-grave environmental impacts of a product. To assess impacts of an emerging technology, LCA should be coupled with additional methods that estimate how that technology might be deployed. The extent and manner that an emerging technology diffuses throughout a region shapes the magnitude and type of environmental impacts. Diffusion of innovation is an established field of research that analyzes the adoption of new innovations, and its principles can be used to construct scenario models that enhance LCA of emerging technologies. Integrating diffusion modeling techniques with an LCA of emerging technology can provide estimates for the extent of market penetration, the displacement of existing systems, and the rate of adoption. Two general perspectives of application are macro-level diffusion models that use a function of time to represent adoption, and microlevel diffusion models that simulate adoption through interactions of individuals. Incorporating diffusion of innovation concepts complement existing methods within LCA to inform proactive environmental management of emerging technologies.

Towards life cycle sustainability assessent of cities. A review of background knowledge.

PubMed

Albertí, Jaume; Balaguera, Alejandra; Brodhag, Christian; Fullana-I-Palmer, Pere

2017-12-31

This article analyses whether existing LCA and sustainability methods can be used in the assessment of a city or an urban region. The approach is performed through the review of current existing LCA-based and sustainability standards and guidelines. A focus is put into those LCA-based standards specially designed for the built environment. Moreover, a review of non-LCA based standards, indices and guides for the assessment of the sustainability of countries, cities or urban regions is done. The purpose is to check if these assessment tools can provide good results in the absence of LCA-based assessments for cities and urban regions. This review demonstrates the lack of consensus in the definition of both, the city and its boundaries, which hinders the development of useful sustainability standards. Furthermore, it is concluded that current sustainability assessment tools miss, at least, one of these aspects: (i) holistic point of view, (ii) focus on various environmental impacts, (iii) a Life Cycle (LC) perspective, and (iv) the possibility to compare the results among different cities or urban regions. From the LCA perspective, the deficiencies found also include the need for a definition of the function, functional unit (FU), and reference flow (RF) of neighbourhoods, cities, and urban regions. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and Evaluation of Vitamin D Receptor-Mediated Activities of Cholesterol and Vitamin D Metabolites

PubMed Central

Teske, Kelly A.; Bogart, Jonathan W.; Sanchez, Luis M.; Yu, Olivia B.; Preston, Joshua V.; Cook, James M.; Silvaggi, Nicholas R.; Bikle, Daniel D.; Arnold, Leggy A.

2016-01-01

A systematic study with phase 1 and phase 2 metabolites of cholesterol and vitamin D was conducted to determine whether their biological activity is mediated by the vitamin D receptor (VDR). The investigation necessitated the development of novel synthetic routes for lithocholic acid (LCA) glucuronides (Gluc). Biochemical and cell-based assays were used to demonstrate that hydroxylated LCA analogs were not able to bind VDR. This excludes VDR from mediating their biological and pharmacological activities. Among the synthesized LCA conjugates a novel VDR agonist was identified. LCA Gluc II increased the expression of CYP24A1 in DU145 cancer cells especially in the presence of the endogenous VDR ligand 1,25(OH)2D3. Furthermore, the methyl ester of LCA was identified as novel VDR antagonist. For the first time, we showed that calcitroic acid, the assumed inactive final metabolite of vitamin D, was able to activate VDR-mediated transcription to a higher magnitude than bile acid LCA. Due to a higher metabolic stability in comparison to vitamin D, a very low toxicity, and high concentration in bile and intestine, calcitroic acid is likely to be an important mediator of the protective vitamin D properties against colon cancer. PMID:26774929

Life cycle assessment integrated with thermodynamic analysis of bio-fuel options for solid oxide fuel cells.

PubMed

Lin, Jiefeng; Babbitt, Callie W; Trabold, Thomas A

2013-01-01

A methodology that integrates life cycle assessment (LCA) with thermodynamic analysis is developed and applied to evaluate the environmental impacts of producing biofuels from waste biomass, including biodiesel from waste cooking oil, ethanol from corn stover, and compressed natural gas from municipal solid wastes. Solid oxide fuel cell-based auxiliary power units using bio-fuel as the hydrogen precursor enable generation of auxiliary electricity for idling heavy-duty trucks. Thermodynamic analysis is applied to evaluate the fuel conversion efficiency and determine the amount of fuel feedstock needed to generate a unit of electrical power. These inputs feed into an LCA that compares energy consumption and greenhouse gas emissions of different fuel pathways. Results show that compressed natural gas from municipal solid wastes is an optimal bio-fuel option for SOFC-APU applications in New York State. However, this methodology can be regionalized within the U.S. or internationally to account for different fuel feedstock options. Copyright © 2012 Elsevier Ltd. All rights reserved.

Phylogeography and biogeography of the lower Central American Neotropics: diversification between two continents and between two seas.

PubMed

Bagley, Justin C; Johnson, Jerald B

2014-11-01

Lower Central America (LCA) provides a geologically complex and dynamic, richly biodiverse model for studying the recent assembly and diversification of a Neotropical biota. Here, we review the growing literature of LCA phylogeography studies and their contribution to understanding the origins, assembly, and diversification of the LCA biota against the backdrop of regional geologic and climatic history, and previous biogeographical inquiry. Studies to date reveal that phylogeographical signal within taxa of differing distributions reflects a diversity of patterns and processes rivalling the complexities of LCA landscapes themselves. Even so, phylogeography is providing novel insights into regional diversification (e.g. cryptic lineage divergences), and general evolutionary patterns are emerging. Congruent multi-taxon phylogeographic breaks are found across the Nicaraguan depression, Chorotega volcanic front, western and central Panama, and the Darién isthmus, indicating that a potentially shared history of responses to regional-scale (e.g. geological) processes has shaped the genetic diversity of LCA communities. By contrast, other species show unique demographic histories in response to overriding historical events, including no phylogeographic structure at all. These low-structure or incongruent patterns provide some evidence for a role of local, ecological factors (e.g. long-distance dispersal and gene flow in plants and bats) in shaping LCA communities. Temporally, comparative phylogeographical structuring reflects Pliocene-Pleistocene dispersal and vicariance events consistent with the timeline of emergence of the LCA isthmus and its major physiographic features, e.g. cordilleras. We emphasise the need to improve biogeographic inferences in LCA through in-depth comparative phylogeography projects capitalising on the latest statistical phylogeographical methods. While meeting the challenges of reconstructing the biogeographical history of this complex region, phylogeographers should also take up the critical service to society of applying their work to the conservation of its fascinating biodiversity. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

To BECCS or Not To BECCS: A Question of Method

NASA Astrophysics Data System (ADS)

DeCicco, J. M.

2017-12-01

Bioenergy with carbon capture and storage (BECCS) is seen as an important option in many climate stabilization scenarios. Limited demonstrations are underway, including a system that captures and sequesters the fermentation CO2 from ethanol production. However, its net CO2 emissions are uncertain for reasons related to both system characteristics and methodological issues. As for bioenergy in general, evaluations draw on both ecological and engineering methods. It is informative to apply different methods using available data for demonstration systems in comparison to related bioenergy systems. To do so, this paper examines a case study BECCS system and addresses questions regarding the utilization of terrestrial carbon, biomass sustainability and the implications for scalability. The analysis examines four systems, all utilizing the same land area, using two methods. The cases are: A) a crop system without either biofuel production or CCS; B) a biofuel production system without CCS; C) biofuel system with CCS, i.e., the BECCS case, and D) a crop system without biofuel production or CCS but with crop residue removal and conversion to a stable char. In cases A and D, the delivered fuel is fossil-based; in cases B and C the fuel is biomass-based. The first method is LCA, involving steady-flow modeling of systems over a defined lifecycle, following current practice as seen in the attributional LCA component of California's Low-Carbon Fuel Standard (LCFS). The second method involves spatially and temporally explicit analysis, reflecting the dynamics of carbon exchanges with the atmosphere. Although parameters are calibrated to the California LCFS LCA model, simplified spreadsheet modeling is used to maximize transparency while highlighting assumptions that most influence the results. The analysis reveals distinctly different pictures of net CO2 emissions for the cases examined, with the dynamic method painting a less optimistic picture of the BECCS system than the LCA method. Differences in results are traced to differing representations of terrestrial carbon exchanges and associated modeling assumptions. We conclude with suggestions for future work on project- and program-scale carbon accounting methods and the need for caution in advancing BECCS before such methods are better validated.

Life Cycle Energy Analysis of Reclaimed Water Reuse Projects in Beijing.

PubMed

Fan, Yupeng; Guo, Erhui; Zhai, Yuanzheng; Chang, Andrew C; Qiao, Qi; Kang, Peng

2018-01-01

  To illustrate the benefits of water reuse project, the process-based life cycle analysis (LCA) could be combined with input-output LCA to evaluate the water reuse project. Energy is the only evaluation parameter used in this study. Life cycle assessment of all energy inputs (LCEA) is completed mainly by the life cycle inventory (LCI), taking into account the full life cycle including the construction, the operation, and the demolition phase of the project. Assessment of benefit from water reuse during the life cycle should focus on wastewater discharge reduction and water-saving benefits. The results of LCEA of Beijing water reuse project built in 2014 in a comprehensive way shows that the benefits obtained from the reclaimed water reuse far exceed the life cycle energy consumption. In this paper, the authors apply the LCEA model to estimate the benefits of reclaimed water reuse projects quantitatively.

LIFE CYCLE INVENTORY ANALYSIS IN THE PRODUCTION OF METALS USED IN PHOTOVOLTAICS.

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

FTHENAKIS,V.M.; KIM, H.C.; WANG, W.

2007-03-30

Material flows and emissions in all the stages of production of zinc, copper, aluminum, cadmium, indium, germanium, gallium, selenium, tellurium, and molybdenum were investigated. These metals are used selectively in the manufacture of solar cells, and emission and energy factors in their production are used in the Life Cycle Analysis (LCA) of photovoltaics. Significant changes have occurred in the production and associated emissions for these metals over the last 10 years, which are not described in the LCA databases. Furthermore, emission and energy factors for several of the by-products of the base metal production were lacking. This report aims inmore » updating the life-cycle inventories associated with the production of the base metals (Zn, Cu, Al, Mo) and in defining the emission and energy allocations for the minor metals (Cd, In, Ge, Se, Te and Ga) used in photovoltaics.« less

Meta-analysis and Harmonization of Life Cycle Assessment Studies for Algae Biofuels.

PubMed

Tu, Qingshi; Eckelman, Matthew; Zimmerman, Julie

2017-09-05

Algae biodiesel (BioD) and renewable diesel (RD) have been recognized as potential solutions to mitigating fossil-fuel consumption and the associated environmental issues. Life cycle assessment (LCA) has been used by many researchers to evaluate the potential environmental impacts of these algae-derived fuels, yielding a wide range of results and, in some cases, even differing on indicating whether these fuels are preferred to petroleum-derived fuels or not. This meta-analysis reviews the methodological preferences and results for energy consumption, greenhouse gas emissions, and water consumption for 54 LCA studies that considered algae BioD and RD. The significant variation in reported results can be primarily attributed to the difference in scope, assumptions, and data sources. To minimize the variation in life cycle inventory calculations, a harmonized inventory data set including both nominal and uncertainty data is calculated for each stage of the algae-derived fuel life cycle.

Probabilistic performance-based design for high performance control systems

NASA Astrophysics Data System (ADS)

Micheli, Laura; Cao, Liang; Gong, Yongqiang; Cancelli, Alessandro; Laflamme, Simon; Alipour, Alice

2017-04-01

High performance control systems (HPCS) are advanced damping systems capable of high damping performance over a wide frequency bandwidth, ideal for mitigation of multi-hazards. They include active, semi-active, and hybrid damping systems. However, HPCS are more expensive than typical passive mitigation systems, rely on power and hardware (e.g., sensors, actuators) to operate, and require maintenance. In this paper, a life cycle cost analysis (LCA) approach is proposed to estimate the economic benefit these systems over the entire life of the structure. The novelty resides in the life cycle cost analysis in the performance based design (PBD) tailored to multi-level wind hazards. This yields a probabilistic performance-based design approach for HPCS. Numerical simulations are conducted on a building located in Boston, MA. LCA are conducted for passive control systems and HPCS, and the concept of controller robustness is demonstrated. Results highlight the promise of the proposed performance-based design procedure.

Assessing and mapping spatial associations among oral cancer mortality rates, concentrations of heavy metals in soil, and land use types based on multiple scale data.

PubMed

Lin, Wei-Chih; Lin, Yu-Pin; Wang, Yung-Chieh; Chang, Tsun-Kuo; Chiang, Li-Chi

2014-02-21

In this study, a deconvolution procedure was used to create a variogram of oral cancer (OC) rates. Based on the variogram, area-to-point (ATP) Poisson kriging and p-field simulation were used to downscale and simulate, respectively, the OC rate data for Taiwan from the district scale to a 1 km × 1 km grid scale. Local cluster analysis (LCA) of OC mortality rates was then performed to identify OC mortality rate hot spots based on the downscaled and the p-field-simulated OC mortality maps. The relationship between OC mortality and land use was studied by overlapping the maps of the downscaled OC mortality, the LCA results, and the land uses. One thousand simulations were performed to quantify local and spatial uncertainties in the LCA to identify OC mortality hot spots. The scatter plots and Spearman's rank correlation yielded the relationship between OC mortality and concentrations of the seven metals in the 1 km cell grid. The correlation analysis results for the 1 km scale revealed a weak correlation between OC mortality rate and concentrations of the seven studied heavy metals in soil. Accordingly, the heavy metal concentrations in soil are not major determinants of OC mortality rates at the 1 km scale at which soils were sampled. The LCA statistical results for local indicator of spatial association (LISA) revealed that the sites with high probability of high-high (high value surrounded by high values) OC mortality at the 1 km grid scale were clustered in southern, eastern, and mid-western Taiwan. The number of such sites was also significantly higher on agricultural land and in urban regions than on land with other uses. The proposed approach can be used to downscale and evaluate uncertainty in mortality data from a coarse scale to a fine scale at which useful additional information can be obtained for assessing and managing land use and risk.

Life-cycle Analysis of Bioproducts and Their Conventional Counterparts in GREET

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

Dunn, Jennifer B.; Adom, Felix; Sather, Norm

To further expand upon the literature in this field and to develop a platform for bioproduct LCA, we developed LCA results for ten bioproducts produced either from algal glycerol or from corn stover-derived sugars. We used Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREETTM) model as the platform for this study. The data and calculations reported herein are available to GREET users in a bioproducts module included in the fall 2015 GREET release. This report documents our approach to this analysis and the results. In Chapter 2, we review the process we underwent to selectmore » the bioproducts for analysis based on market and technology readiness criteria. In Chapter 3, we review key parameters for production of the two feedstocks we considered: corn stover and algae. Given the lack of publicly available information about the production of bioproducts, which is caused in large part by the emerging nature of the industry, we developed Aspen Plus® simulations of the processes that could be used to produce each bioproduct. From these simulations, we extracted the energy and material flows of these processes, which were important inputs to the GREET bioproducts module. Chapter 4 provides the details of these Aspen Plus simulations. It is important to compare the LCA results for bioproducts to those for their petroleum counterparts. We therefore also developed material and energy flow data for conventional products based mostly on the literature. These data are described in Chapter 5 and are also included in the GREET bioproducts module. In Chapter 6, we present results from this analysis and examine areas for refinement and future research.« less

Socio-economic analysis: a tool for assessing the potential of nanotechnologies

NASA Astrophysics Data System (ADS)

Brignon, Jean-Marc

2011-07-01

Cost-Benefit Analysis (CBA) has a long history, especially in the USA, of being used for the assessment of new regulation, new infrastructure and more recently for new technologies. Under the denomination of Socio-Economic Analysis (SEA), this concept is used in EU safety and environmental regulation, especially for the placing of chemicals on the market (REACh regulation) and the operation of industrial installations (Industrial Emissions Directive). As far as REACh and other EU legislation apply specifically to nanomaterials in the future, SEA might become an important assessment tool for nanotechnologies. The most important asset of SEA regarding nanomaterials, is the comparison with alternatives in socio-economic scenarios, which is key for the understanding of how a nanomaterial "socially" performs in comparison with its alternatives. "Industrial economics" methods should be introduced in SEAs to make industry and the regulator share common concepts and visions about economic competitiveness implications of regulating nanotechnologies, SEA and Life Cycle Analysis (LCA) can complement each other : Socio-Economic LCA are increasingly seen as a complete assessment tool for nanotechnologies, but the perspective between Social LCA and SEA are different and the respective merits and limitations of both approaches should be kept in mind. SEA is a "pragmatic regulatory impact analysis", that uses a cost/benefit framework analysis but remains open to other disciplines than economy, and open to the participation of stakeholders for the construction of scenarios of the deployment of technologies and the identification of alternatives. SEA is "pragmatic" in the sense that it is driven by the purpose to assess "what happens" with the introduction of nanotechnology, and uses methodologies such as Life Cycle Analysis only as far as they really contribute to that goal. We think that, being pragmatic, SEA is also adaptative, which is a key quality to handle the novelty of economic and social effects expected from nanotechnology.

Longitudinal chromatic aberration of the human eye in the visible and near infrared from wavefront sensing, double-pass and psychophysics

PubMed Central

Vinas, Maria; Dorronsoro, Carlos; Cortes, Daniel; Pascual, Daniel; Marcos, Susana

2015-01-01

Longitudinal Chromatic Aberration (LCA) influences the optical quality of the eye. However, the reported LCA varies across studies, likely associated to differences in the measurement techniques. We present LCA measured in subjects using wavefront sensing, double-pass retinal images, and psychophysical methods with a custom-developed polychromatic Adaptive Optics system in a wide spectral range (450-950 nm), with control of subjects’ natural aberrations. LCA measured psychophysically was significantly higher than that from reflectometric techniques (1.51 D vs 1.00 D in the 488-700 nm range). Ours results indicate that the presence of natural aberrations is not the cause for the discrepancies across techniques. PMID:25798317

The vertebral formula of the last common ancestor of African apes and humans.

PubMed

McCollum, Melanie A; Rosenman, Burt A; Suwa, Gen; Meindl, Richard S; Lovejoy, C Owen

2010-03-15

The modal number of lumbar vertebrae in modern humans is five. It varies between three and four in extant African apes (mean=3.5). Because both chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) possess the same distributions of thoracic, lumbar, and sacral vertebrae, it has been assumed from parsimony that the last common ancestor (LCA) of African apes and humans possessed a similarly short lower back. This "short-backed LCA" scenario has recently been viewed favorably in an analysis of the intra- and interspecific variation in axial formulas observed among African apes and humans (Pilbeam, 2004. J Exp Zool 302B:241-267). However, the number of bonobo (Pan paniscus) specimens in that study was small (N=17). Here we reconsider vertebral type and number in the LCA in light of an expanded P. paniscus sample as well as evidence provided by the human fossil record. The precaudal (pre-coccygeal) axial column of bonobos differs from those of chimpanzees and gorillas in displaying one additional vertebra as well as significantly different combinations of sacral, lumbar, and thoracic vertebrae. These findings, along with the six-segmented lumbar column of early Australopithecus and early Homo, suggest that the LCA possessed a long axial column and long lumbar spine and that reduction in the lumbar column occurred independently in humans and in each ape clade, and continued after separation of the two species of Pan as well. Such an explanation is strongly congruent with additional details of lumbar column reduction and lower back stabilization in African apes.

Life-Cycle Analysis and Inquiry-Based Learning in Chemistry Teaching

ERIC Educational Resources Information Center

Juntunen, Marianne; Aksela, Maija

2013-01-01

The purpose of this design research is to improve the quality of environmental literacy and sustainability education in chemistry teaching through combining a socio-scientific issue, life-cycle analysis (LCA), with inquiry-based learning (IBL). This first phase of the cyclic design research involved 20 inservice trained chemistry teachers from…

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

McManus, Marcelle C.; Taylor, Caroline M.; Mohr, Alison

Purpose: Bioenergy is increasingly used to help meet greenhouse gas (GHG) and renewable energy targets. However, bioenergy’s sustainability has been questioned, resulting in increasing use of life cycle assessment (LCA). Bioenergy systems are global and complex, and market forces can result in significant changes, relevant to LCA and policy. The goal of this paper is to illustrate the complexities associated with LCA, with particular focus on bioenergy and associated policy development, so that its use can more effectively inform policymakers. Methods: The review is based on the results from a series of workshops focused on bioenergy life cycle assessment. Expertmore » submissions were compiled and categorized within the first two workshops. Over 100 issues emerged. Accounting for redundancies and close similarities in the list, this reduced to around 60 challenges, many of which are deeply interrelated. Some of these issues were then explored further at a policy-facing workshop in London, UK. The authors applied a rigorous approach to categorize the challenges identified to be at the intersection of biofuels/bioenergy LCA and policy. Results and discussion: The credibility of LCA is core to its use in policy. Even LCAs that comply with ISO standards and policy and regulatory instruments leave a great deal of scope for interpretation and flexibility. Within the bioenergy sector, this has led to frustration and at times a lack of obvious direction. This paper identifies the main challenge clusters: overarching issues, application and practice and value and ethical judgments. Many of these are reflective of the transition from application of LCA to assess individual products or systems to the wider approach that is becoming more common. Uncertainty in impact assessment strongly influences planning and compliance due to challenges in assigning accountability, and communicating the inherent complexity and uncertainty within bioenergy is becoming of greater importance. Conclusions: The emergence of LCA in bioenergy governance is particularly significant because other sectors are likely to transition to similar governance models. LCA is being stretched to accommodate complex and broad policy-relevant questions, seeking to incorporate externalities that have major implications for long-term sustainability. As policy increasingly relies on LCA, the strains placed on the methodology are becoming both clearer and impedimentary. The implications for energy policy, and in particular bioenergy, are large.« less

Variations in embodied energy and carbon emission intensities of construction materials

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

Wan Omar, Wan-Mohd-Sabki; School of Environmental Engineering, Universiti Malaysia Perlis, 02600 Arau, Perlis; Doh, Jeung-Hwan, E-mail: j.doh@griffith.edu.au

2014-11-15

Identification of parameter variation allows us to conduct more detailed life cycle assessment (LCA) of energy and carbon emission material over their lifecycle. Previous research studies have demonstrated that hybrid LCA (HLCA) can generally overcome the problems of incompleteness and accuracy of embodied energy (EE) and carbon (EC) emission assessment. Unfortunately, the current interpretation and quantification procedure has not been extensively and empirically studied in a qualitative manner, especially in hybridising between the process LCA and I-O LCA. To determine this weakness, this study empirically demonstrates the changes in EE and EC intensities caused by variations to key parameters inmore » material production. Using Australia and Malaysia as a case study, the results are compared with previous hybrid models to identify key parameters and issues. The parameters considered in this study are technological changes, energy tariffs, primary energy factors, disaggregation constant, emission factors, and material price fluctuation. It was found that changes in technological efficiency, energy tariffs and material prices caused significant variations in the model. Finally, the comparison of hybrid models revealed that non-energy intensive materials greatly influence the variations due to high indirect energy and carbon emission in upstream boundary of material production, and as such, any decision related to these materials should be considered carefully. - Highlights: • We investigate the EE and EC intensity variation in Australia and Malaysia. • The influences of parameter variations on hybrid LCA model were evaluated. • Key significant contribution to the EE and EC intensity variation were identified. • High indirect EE and EC content caused significant variation in hybrid LCA models. • Non-energy intensive material caused variation between hybrid LCA models.« less

Comparative Myology and Evolution of Marsupials and Other Vertebrates, With Notes on Complexity, Bauplan, and "Scala Naturae".

PubMed

Diogo, Rui; Bello-Hellegouarch, Gaelle; Kohlsdorf, Tiana; Esteve-Altava, Borja; Molnar, Julia L

2016-09-01

Opossums are frequent subjects of developmental studies because marsupials share developmental features not seen in placentals and because Didelphimorpha is the sister-group of other extant Marsupialia. But is the adult marsupial muscular system markedly different from that of placentals or is it, like the skeletal system, very similar? We provide, for the first time, a brief description of all head and limb muscles of Didelphis virginiana based on our dissections and using a unifying nomenclature by integrating the data gathered in our long-term project on the development, homologies, and evolution of the muscles of all major vertebrate taxa. Our data indicate that there were many more muscle synapomorphic changes from the last common ancestor (LCA) of amniotes to the mammalian LCA (63) and from this LCA to the LCA of extant therians (48) than from this latter LCA to the LCA of extant placentals (10 or 11). Importantly, Didelphis is anatomically more plesiomorphic (only 14 changes from LCA of extant therians) than are rats (37 changes) and humans (63 changes), but its musculature is more complex (193 muscles) than that of humans (only 180 muscles). Of the 194 muscles of Didelphis, 172 (89%) are present in rats, meaning that their adult muscle anatomy is indeed very similar. This similarity supports the existence of a common, easy recognizable therian Bauplan, but one that is caused by developmental constraints and by evolutionary change driven by the needs of the embryos/neonates, rather than by a "goal" toward a specific adult plan/"archetype," as the name Bauplan suggests. Anat Rec, 299:1224-1255, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Towards a meaningful assessment of marine ecological impacts in life cycle assessment (LCA).

PubMed

Woods, John S; Veltman, Karin; Huijbregts, Mark A J; Verones, Francesca; Hertwich, Edgar G

2016-01-01

Human demands on marine resources and space are currently unprecedented and concerns are rising over observed declines in marine biodiversity. A quantitative understanding of the impact of industrial activities on the marine environment is thus essential. Life cycle assessment (LCA) is a widely applied method for quantifying the environmental impact of products and processes. LCA was originally developed to assess the impacts of land-based industries on mainly terrestrial and freshwater ecosystems. As such, impact indicators for major drivers of marine biodiversity loss are currently lacking. We review quantitative approaches for cause-effect assessment of seven major drivers of marine biodiversity loss: climate change, ocean acidification, eutrophication-induced hypoxia, seabed damage, overexploitation of biotic resources, invasive species and marine plastic debris. Our review shows that impact indicators can be developed for all identified drivers, albeit at different levels of coverage of cause-effect pathways and variable levels of uncertainty and spatial coverage. Modeling approaches to predict the spatial distribution and intensity of human-driven interventions in the marine environment are relatively well-established and can be employed to develop spatially-explicit LCA fate factors. Modeling approaches to quantify the effects of these interventions on marine biodiversity are less well-developed. We highlight specific research challenges to facilitate a coherent incorporation of marine biodiversity loss in LCA, thereby making LCA a more comprehensive and robust environmental impact assessment tool. Research challenges of particular importance include i) incorporation of the non-linear behavior of global circulation models (GCMs) within an LCA framework and ii) improving spatial differentiation, especially the representation of coastal regions in GCMs and ocean-carbon cycle models. Copyright © 2016 Elsevier Ltd. All rights reserved.

Kv7 channels critically determine coronary artery reactivity: left-right differences and down-regulation by hyperglycaemia.

PubMed

Morales-Cano, Daniel; Moreno, Laura; Barreira, Bianca; Pandolfi, Rachele; Chamorro, Virginia; Jimenez, Rosario; Villamor, Eduardo; Duarte, Juan; Perez-Vizcaino, Francisco; Cogolludo, Angel

2015-04-01

Voltage-gated potassium channels encoded by KCNQ genes (Kv7 channels) are emerging as important regulators of vascular tone. In this study, we analysed the contribution of Kv7 channels to the vasodilation induced by hypoxia and the cyclic AMP pathway in the coronary circulation. We also assessed their regional distribution and possible impairment by diabetes. We examined the effects of Kv7 channel modulators on K+ currents and vascular reactivity in rat left and right coronary arteries (LCAs and RCAs, respectively). Currents from LCA were more sensitive to Kv7 channel inhibitors (XE991, linopirdine) and activators (flupirtine, retigabine) than those from RCA. Accordingly, LCAs were more sensitive than RCAs to the relaxation induced by Kv7 channel enhancers. Likewise, relaxation induced by the adenylyl cyclase activator forskolin and hypoxia, which were mediated through Kv7 channel activation, were greater in LCA than in RCA. KCNQ1 and KCNQ5 expression was markedly higher in LCA than in RCA. After incubation with high glucose (HG, 30 mmol/L), myocytes from LCA, but not from RCA, were more depolarized and showed reduced Kv7 currents. In HG-incubated LCA, the effects of Kv7 channel modulators and forskolin were diminished, and the expression of KCNQ1 and KCNQ5 was reduced. Finally, vascular responses induced by Kv7 channel modulators were impaired in LCA, but not in RCA, from type 1 diabetic rats. Our results reveal that the high expression and function of Kv7 channels in the LCA and their down-regulation by diabetes critically determine the sensitivity to key regulators of coronary tone. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Evidence of a chimpanzee-sized ancestor of humans but a gibbon-sized ancestor of apes.

PubMed

Grabowski, Mark; Jungers, William L

2017-10-12

Body mass directly affects how an animal relates to its environment and has a wide range of biological implications. However, little is known about the mass of the last common ancestor (LCA) of humans and chimpanzees, hominids (great apes and humans), or hominoids (all apes and humans), which is needed to evaluate numerous paleobiological hypotheses at and prior to the root of our lineage. Here we use phylogenetic comparative methods and data from primates including humans, fossil hominins, and a wide sample of fossil primates including Miocene apes from Africa, Europe, and Asia to test alternative hypotheses of body mass evolution. Our results suggest, contrary to previous suggestions, that the LCA of all hominoids lived in an environment that favored a gibbon-like size, but a series of selective regime shifts, possibly due to resource availability, led to a decrease and then increase in body mass in early hominins from a chimpanzee-sized LCA.The pattern of body size evolution in hominids can provide insight into historical human ecology. Here, Grabowski and Jungers use comparative phylogenetic analysis to reconstruct the likely size of the ancestor of humans and chimpanzees and the evolutionary history of selection on body size in primates.

Conducting an agricultural life cycle assessment: challenges and perspectives.

PubMed

Caffrey, Kevin R; Veal, Matthew W

2013-12-10

Agriculture is a diverse field that produces a wide array of products vital to society. As global populations continue to grow the competition for natural resources will increase pressure on agricultural production of food, fiber, energy, and various high value by-products. With elevated concerns related to environmental impacts associated with the needs of a growing population, a life cycle assessment (LCA) framework can be used to determine areas of greatest impact and compare reduction strategies for agricultural production systems. The LCA methodology was originally developed for industrial operations but has been expanded to a wider range of fields including agriculture. There are various factors that increase the complexity of determining impacts associated with agricultural production including multiple products from a single system, regional and crop specific management techniques, temporal variations (seasonally and annually), spatial variations (multilocation production of end products), and the large quantity of nonpoint emission sources. The lack of consistent methodology of some impacts that are of major concern to agriculture (e.g., land use and water usage) increases the complexity of this analysis. This paper strives to review some of these issues and give perspective to the LCA practitioner in the field of agriculture.

Conducting an Agricultural Life Cycle Assessment: Challenges and Perspectives

PubMed Central

Caffrey, Kevin R.; Veal, Matthew W.

2013-01-01

Agriculture is a diverse field that produces a wide array of products vital to society. As global populations continue to grow the competition for natural resources will increase pressure on agricultural production of food, fiber, energy, and various high value by-products. With elevated concerns related to environmental impacts associated with the needs of a growing population, a life cycle assessment (LCA) framework can be used to determine areas of greatest impact and compare reduction strategies for agricultural production systems. The LCA methodology was originally developed for industrial operations but has been expanded to a wider range of fields including agriculture. There are various factors that increase the complexity of determining impacts associated with agricultural production including multiple products from a single system, regional and crop specific management techniques, temporal variations (seasonally and annually), spatial variations (multilocation production of end products), and the large quantity of nonpoint emission sources. The lack of consistent methodology of some impacts that are of major concern to agriculture (e.g., land use and water usage) increases the complexity of this analysis. This paper strives to review some of these issues and give perspective to the LCA practitioner in the field of agriculture. PMID:24391463

Influence of the impact assessment method on the conclusions of a LCA study. Application to the case of a part made with virgin and recycled HDPE.

PubMed

Simões, Carla L; Xará, Susana M; Bernardo, C A

2011-10-01

Recent legislation has stressed the need to decide the best end-of-life (EoL) option for post-consumer products considering their full life-cycle and the corresponding overall environmental impacts. The life cycle assessment (LCA) technique has become a common tool to evaluate those impacts. The present study aimed to contribute to the better understanding of the application of this technique, by evaluating the influence of the selection of the life cycle impact assessment (LCIA) method in its results and conclusions. A specific case study was chosen, using previous information related to an anti-glare lamellae (AGL) for highway use, made with virgin and recycled high-density polyethylene (HDPE). Five distinct LCIA methods were used: Eco-indicator 99, CML 2 (2000), EPS 2000, Eco-indicator 95 and EDIP 97. Consistent results between these methods were obtained for the Climate change, Ozone layer depletion, Acidification and Eutrophication environmental indicators. Conversely, the Summer smog indicator showed large discrepancies between impact assessment methods. The work sheds light on the advantages inherent in using various LCIA methods when doing the LCA study of a specific product, thus evidencing complementary analysis perspectives.

Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments

NASA Astrophysics Data System (ADS)

Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

2017-01-01

Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). In this study we calculated the GWPbio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWPbio factors ranged from 0.13-0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWPbio. Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWPbio and energy conversion efficiency. By considering the GWPbio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWPbio.

Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments

PubMed Central

Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

2017-01-01

Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO2 (GWPbio). In this study we calculated the GWPbio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWPbio factors ranged from 0.13–0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWPbio. Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWPbio and energy conversion efficiency. By considering the GWPbio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWPbio. PMID:28045111

Analysis of the Global Warming Potential of Biogenic CO2 Emission in Life Cycle Assessments.

PubMed

Liu, Weiguo; Zhang, Zhonghui; Xie, Xinfeng; Yu, Zhen; von Gadow, Klaus; Xu, Junming; Zhao, Shanshan; Yang, Yuchun

2017-01-03

Biomass is generally believed to be carbon neutral. However, recent studies have challenged the carbon neutrality hypothesis by introducing metric indicators to assess the global warming potential of biogenic CO 2 (GWP bio ). In this study we calculated the GWP bio factors using a forest growth model and radiative forcing effects with a time horizon of 100 years and applied the factors to five life cycle assessment (LCA) case studies of bioproducts. The forest carbon change was also accounted for in the LCA studies. GWP bio factors ranged from 0.13-0.32, indicating that biomass could be an attractive energy resource when compared with fossil fuels. As expected, short rotation and fast-growing biomass plantations produced low GWP bio . Long-lived wood products also allowed more regrowth of biomass to be accounted as absorption of the CO 2 emission from biomass combustion. The LCA case studies showed that the total life cycle GHG emissions were closely related to GWP bio and energy conversion efficiency. By considering the GWP bio factors and the forest carbon change, the production of ethanol and bio-power appeared to have higher GHG emissions than petroleum-derived diesel at the highest GWP bio .

Life Cycle Assessment for Proton Conducting Ceramics Synthesized by the Sol-Gel Process.

PubMed

Lee, Soo-Sun; Hong, Tae-Whan

2014-09-16

In this report, the environmental aspects of producing proton conducting ceramics are investigated by means of the environmental Life Cycle Assessment (LCA) method. The proton conducting ceramics BaZr 0.8 Y 0.2 O 3-δ (BZY), BaCe 0.9 Y 0.1 O 2.95 (BCY10), and Sr(Ce 0.9 Zr 0.1 ) 0.95 Yb 0.05 O 3-δ (SCZY) were prepared by the sol-gel process. Their material requirements and environmental emissions were inventoried, and their energy requirements were determined, based on actual production data. This latter point makes the present LCA especially worthy of attention as a preliminary indication of future environmental impact. The analysis was performed according to the recommendations of ISO norms 14040 and obtained using the Gabi 6 software. The performance of the analyzed samples was also compared with each other. The LCA results for these proton conducting ceramics production processes indicated that the marine aquatic ecotoxicity potential (MAETP) made up the largest part, followed by fresh-water aquatic ecotoxicity potential (FAETP) and Human Toxicity Potential (HTP). The largest contribution was from energy consumption during annealing and calcinations steps.

Quantifying the Army Supply Chain Water Bootprint

DTIC Science & Technology

2011-12-01

Guns, through 30mm Other FSCs 4-3 Several factors affect the accuracy of this result :  A major drawback of the Eco- LCA model is that each economic...inflated values produced by the Eco- LCA model. In spite of these issues, the resulting Army water bootprint estimate, although coarse, does provide a...for bulk fuel purchases, the Eco- LCA approach results in a water footprint eight times larger than a footprint that uses literature- based water

Air and Space Power Journal. Volume 25, Number 2, Summer 2011

DTIC Science & Technology

2011-01-01

their entire life cycles. The EIO- LCA results give Air Force leaders a basis for evaluating alternative ways of implementing the ser- vice’s energy...strategy. Background Before presenting and discussing the EIO- LCA results , the article addresses envi- ronmental concerns associated with burning fuel...to the EIO- LCA model results , the GWP for the CBTL fuel was 14 percent less than that for the JP-8 fuel, not considering car- bon capture. In other

Effects of Astragalus membranaceus with supplemental calcium on bone mineral density and bone metabolism in calcium-deficient ovariectomized rats.

PubMed

Kang, Se-Chan; Kim, Hee Jung; Kim, Mi-Hyun

2013-01-01

It has been reported that Astragalus membranaceus, an Asian traditional herb, has an estrogenic effect in vitro. To examine the possible role of A. membranaceus extract with supplemental calcium (Ca) on bone status in calcium-deficient (LCa) ovariectomized (OVX) rats, a total of 48 female rats were divided into six groups: (1) normal control, (2) sham operation with LCa (sham-LCa), (3) OVX with LCa (OVX-LCa), (4) A. membranaceus supplementation with OVX-LCa (OVX-MLCa), (5) Ca supplementation with OVX (OVX-Ca), and (6) A. membranaceus and Ca supplementation with OVX (OVX-MCa). A. membranaceus ethanol extract (500 mg/kg BW) and/or Ca (800 mg/kg BW) were administered orally for 8 weeks along with a Ca-deficient diet. Results revealed that Ca supplementation with or without A. membranaceus extract significantly improved bone mineral density, biomechanical strength, and ash weight of the femur and tibia in OVX rats. High Ca with A. membranaceus combination supplementation significantly increased the ash weight of the femur and tibia and decreased urinary Ca excretion compared with supplementation of Ca alone. Uterine weight was not changed by A. membranaceus administration in OVX rats. These results suggest that A. membranaceus extract combined with supplemental Ca may be more protective against the Ca loss of bone than A. membranaceus or supplementation of Ca alone in calcium-insufficient postmenopausal women.

Accommodation to wavefront vergence and chromatic aberration.

PubMed

Wang, Yinan; Kruger, Philip B; Li, James S; Lin, Peter L; Stark, Lawrence R

2011-05-01

Longitudinal chromatic aberration (LCA) provides a cue to accommodation with small pupils. However, large pupils increase monochromatic aberrations, which may obscure chromatic blur. In this study, we examined the effect of pupil size and LCA on accommodation. Accommodation was recorded by infrared optometer while observers (nine normal trichromats) viewed a sinusoidally moving Maltese cross target in a Badal stimulus system. There were two illumination conditions: white (3000 K; 20 cd/m) and monochromatic (550 nm with 10 nm bandwidth; 20 cd/m) and two artificial pupil conditions (3 and 5.7 mm). Separately, static measurements of wavefront aberration were made with the eye accommodating to targets between 0 and 4 D (COAS, Wavefront Sciences). Large individual differences in accommodation to wavefront vergence and to LCA are a hallmark of accommodation. LCA continues to provide a signal at large pupil sizes despite higher levels of monochromatic aberrations. Monochromatic aberrations may defend against chromatic blur at high spatial frequencies, but accommodation responds best to optical vergence and to LCA at 3 c/deg where blur from higher order aberrations is less.

Accommodation to Wavefront Vergence and Chromatic Aberration

PubMed Central

Wang, Yinan; Kruger, Philip B.; Li, James S.; Lin, Peter L.; Stark, Lawrence R.

2011-01-01

Purpose Longitudinal chromatic aberration (LCA) provides a cue to accommodation with small pupils. However, large pupils increase monochromatic aberrations, which may obscure chromatic blur. In the present study, we examined the effect of pupil size and LCA on accommodation. Methods Accommodation was recorded by infrared optometer while observers (nine normal trichromats) viewed a sinusoidally moving Maltese cross target in a Badal stimulus system. There were two illumination conditions: white (3000 K; 20 cd/m2) and monochromatic (550 nm with 10 nm bandwidth; 20 cd/m2) and two artificial pupil conditions (3 mm and 5.7 mm). Separately, static measurements of wavefront aberration were made with the eye accommodating to targets between 0 and 4 D (COAS, Wavefront Sciences). Results Large individual differences in accommodation to wavefront vergence and to LCA are a hallmark of accommodation. LCA continues to provide a signal at large pupil sizes despite higher levels of monochromatic aberrations. Conclusions Monochromatic aberrations may defend against chromatic blur at high spatial frequencies, but accommodation responds best to optical vergence and to LCA at 3 c/deg where blur from higher order aberrations is less. PMID:21317666

An active coronagraph using a liquid crystal array for exoplanet imaging: principle and testing

NASA Astrophysics Data System (ADS)

Zhang, Xi; Ren, De-Qing; Zhu, Yong-Tian; Dou, Jiang-Pei

2012-05-01

High-contrast imaging coronagraphs, used for the detection of exoplanets, have always adopted passive coronagraph optical components. It is therefore impossible to actively optimize the coronagraphs to achieve their best performance. To solve this problem, we propose a novel high-contrast imaging coronagraph which combines a liquid crystal array (LCA) for active pupil apodization and a deformable mirror (DM) for phase correction. The LCA we use is an amplitude-only spatial light modulator. The LCA is well calibrated and compensates for its amplitude non-uniformity and nonlinear intensity responsivity. We measured the imaging contrasts of the coronagraph system with the LCA only and without the DM deployed. Imaging contrasts of 10-4 and 10-5 can be reached at an inner working angular distance of 2.5 and 5λ/D, respectively. A simulation shows that the phase errors on the coronagraph pupil limit the contrast performance. The contrast could be further improved if a DM is deployed to correct the phase errors induced by the LCA and coronagraph optics.

The facial skeleton of the chimpanzee-human last common ancestor

PubMed Central

Cobb, Samuel N

2008-01-01

This review uses the current morphological evidence to evaluate the facial morphology of the hypothetical last common ancestor (LCA) of the chimpanzee/bonobo (panin) and human (hominin) lineages. Some of the problems involved in reconstructing ancestral morphologies so close to the formation of a lineage are discussed. These include the prevalence of homoplasy and poor phylogenetic resolution due to a lack of defining derived features. Consequently the list of hypothetical features expected in the face of the LCA is very limited beyond its hypothesized similarity to extant Pan. It is not possible to determine with any confidence whether the facial morphology of any of the current candidate LCA taxa (Ardipithecus kadabba, Ardipithecus ramidus, Orrorin tugenensis and Sahelanthropus tchadensis) is representative of the LCA, or a stem hominin, or a stem panin or, in some cases, a hominid predating the emergence of the hominin lineage. The major evolutionary trends in the hominin lineage subsequent to the LCA are discussed in relation to the dental arcade and dentition, subnasal morphology and the size, position and prognathism of the facial skeleton. PMID:18380866

Unusual Survival of Anomalous Left Coronary Artery From the Pulmonary Artery With Severe Rheumatic Mitral Stenosis in Septuagenarian Women: Foes Becoming Friends?

PubMed

Sinha, Santosh Kumar; Khanra, Dibbendhu; Jha, Mukesh Jitendra; Singh, Karandeep; Razi, Mahamdulla; Goel, Amit; Mishra, Vikas; Asif, Mohammad; Sachan, Mohit; Afdaali, Nasar; Kumar, Ashutosh; Thakur, Ramesh; Krishna, Vinay; Pandey, Umeshwar; Varma, Chandra Mohan

2016-10-01

ALCAPA syndrome (anomalous origin of the left coronary artery from the pulmonary artery) is a rare disease but lethal with clinical expression from myocardial infarction, congestive heart failure to death during early infancy and unusual survival to adulthood. We report a 73-year-old woman with ALCAPA who presented with exertional dyspnea (NYHA functional class II) over past 2 years. Physical examination revealed soft S, long mid diastolic rumbling murmur and apical pan-systolic murmur. Electrocardiography displayed biatrial enlargement and poor R progression and normal sinus rhythm. Echocardiography established calcified severe mitral stenosis (MS), presence of continuous flow entering the pulmonary trunk, turbulent continuous flow in inter-ventricular septum with left to right shunt in contrast echocardiography and normal systolic function. Coronary angiogram showed absence of left coronary artery (LCA) originating from aorta, dilated and tortuous right coronary artery (RCA) and abundant Rentrop grade 3 intercoronary collateral communicating with LCA originating from pulmonary trunk which was also confirmed on coronary CT angiogram thus establishing diagnosis of ALCAPA. It is exceedingly rare to be associated with severe MS. However, such a long survival in our patient can be explained by the severe pulmonary arterial hypertension which may be contributing to lesser coronary steal.

Application of stochastic approach based on Monte Carlo (MC) simulation for life cycle inventory (LCI) of the rare earth elements (REEs) in beneficiation rare earth waste from the gold processing: case study

NASA Astrophysics Data System (ADS)

Bieda, Bogusław; Grzesik, Katarzyna

2017-11-01

The study proposes an stochastic approach based on Monte Carlo (MC) simulation for life cycle assessment (LCA) method limited to life cycle inventory (LCI) study for rare earth elements (REEs) recovery from the secondary materials processes production applied to the New Krankberg Mine in Sweden. The MC method is recognizes as an important tool in science and can be considered the most effective quantification approach for uncertainties. The use of stochastic approach helps to characterize the uncertainties better than deterministic method. Uncertainty of data can be expressed through a definition of probability distribution of that data (e.g. through standard deviation or variance). The data used in this study are obtained from: (i) site-specific measured or calculated data, (ii) values based on literature, (iii) the ecoinvent process "rare earth concentrate, 70% REO, from bastnäsite, at beneficiation". Environmental emissions (e.g, particulates, uranium-238, thorium-232), energy and REE (La, Ce, Nd, Pr, Sm, Dy, Eu, Tb, Y, Sc, Yb, Lu, Tm, Y, Gd) have been inventoried. The study is based on a reference case for the year 2016. The combination of MC analysis with sensitivity analysis is the best solution for quantified the uncertainty in the LCI/LCA. The reliability of LCA results may be uncertain, to a certain degree, but this uncertainty can be noticed with the help of MC method.

Friends or foes? Monetized Life Cycle Assessment and Cost-Benefit Analysis of the site remediation of a former gas plant.

PubMed

Huysegoms, Lies; Rousseau, Sandra; Cappuyns, Valérie

2018-04-01

Site contamination is a global concern because of the potential risks for human health and ecosystem quality. Every contaminated site has its own specific characteristics and the increased availability and efficiency of remediation techniques makes the choice of remediation alternative increasingly complicated. In this paper an attributional Life Cycle Assessment (LCA) of the secondary environmental impacts of a site remediation is performed and its results are monetized using two different monetization techniques, namely Stepwise 2006 and Ecovalue 08. Secondly, we perform a social Cost-Benefit Analysis (CBA) on the same case study using the same data sources. The case study used in this paper entails the soil and groundwater remediation of a tar, poly-aromatic hydrocarbons (PAH) and cyanide contamination of a school ground by a former gas plant. The remediation alternative chosen in this case study is excavation with off-site thermal treatment of the contaminated soil. The outcome of the social CBA, stating that the remediation project is socially beneficial in the long term, is critically compared to the outcome of the different LCA monetization methods. This comparison indicates that monetized LCA is a good complement to social CBA when it comes to the assessment of secondary environmental impacts. Combining the two methods provides decision makers with a more extensive and detailed assessment of the soil remediation project. Copyright © 2017 Elsevier B.V. All rights reserved.

An Economic Analysis of Investment in the United States Shipbuilding Industry

DTIC Science & Technology

2010-06-01

using U.S. Bureau of Economic Analysis (BEA) input/output data and the “Leontief inversion process” modeled at Carnegie Mellon University. This... modeled at Carnegie Mellon University. This sector was compared with five alternative investments. Second, the benefits of the shipyard-related...EIO-LCA Model ..................................39 2. Shipyard Direct Labor Trends .........................................................43 viii 3

Computational Tools for Probing Interactions in Multiple Linear Regression, Multilevel Modeling, and Latent Curve Analysis

ERIC Educational Resources Information Center

Preacher, Kristopher J.; Curran, Patrick J.; Bauer, Daniel J.

2006-01-01

Simple slopes, regions of significance, and confidence bands are commonly used to evaluate interactions in multiple linear regression (MLR) models, and the use of these techniques has recently been extended to multilevel or hierarchical linear modeling (HLM) and latent curve analysis (LCA). However, conducting these tests and plotting the…

Pronounced occurrence of long-chain alkenones and dinosterol in a 25,000-year lipid molecular fossil record from Lake Titicaca, South America

NASA Astrophysics Data System (ADS)

Theissen, Kevin M.; Zinniker, David A.; Moldowan, J. Michael; Dunbar, Robert B.; Rowe, Harold D.

2005-02-01

Our analysis of lipid molecular fossils from a Lake Titicaca (16° S, 69° W) sediment core reveals distinct changes in the ecology of the lake over an ˜25,000-yr period spanning latest Pleistocene to late Holocene time. Previous investigations have shown that over this time period Lake Titicaca was subject to large changes in lake level in response to regional climatic variability. Our results indicate that lake algal populations were greatly affected by the changing physical and chemical conditions in Lake Titicaca. Hydrocarbons are characterized by a combination of odd-numbered, mid- to long-chain (C 21-C 31) normal alkanes and alkenes. During periods when lake level was higher (latest Pleistocene, early Holocene, and late Holocene), the C 21n-alkane, and the C 25 and C 27 alkenes dominate hydrocarbon distributions and indicate contribution from an algal source, potentially the freshwater alga Botryococcus braunii. The C 30 4 α-methyl sterol (dinosterol) increases sharply during the mid-Holocene, suggesting a greatly increased dinoflagellate presence at that time. Long-chain alkenones (LCAs) become significant during the early Holocene and are highly abundant in mid-Holocene samples. There are relatively few published records of LCA detection in lake sediments but their occurrence is geographically widespread (Antarctica, Asia, Europe, North America). Lake Titicaca represents the first South American lake and the first low-latitude lake in which LCAs have been reported. LCA abundance and distribution may be related to the temperature-dependent response of an unidentified algal precursor. Although the LCA unsaturation indices cannot be used to determine absolute Lake Titicaca temperatures, we suspect that the published LCA U37K unsaturation calibrations can be applied to infer relative temperatures for early to mid-Holocene time when LCA concentrations are high. Using these criteria, the U37K unsaturation indices suggest relatively warmer temperatures in the mid-Holocene. In contrast to previous speculation, lipid analysis provides little evidence of a greatly increased presence of aquatic plants during the mid-Holocene. Instead, it appears that a few algal species were dominant in the lake. Based on the dramatic rise in abundances of LCAs and dinosterol during the early to mid-Holocene, we suspect that the algal producers of these compounds rose in response to a combination of physical and chemical changes in the lake. These include temperature, salinity, and alkalinity changes that occurred as lake level dropped sharply during a multi-millennial drought affecting the Central Andean Altiplano.

Autosomal-dominant Leber Congenital Amaurosis Caused by a Heterozygous CRX Mutation in a Father and Son.

PubMed

Arcot Sadagopan, Karthikeyan; Battista, Robert; Keep, Rosanne B; Capasso, Jenina E; Levin, Alex V

2015-06-01

Leber congenital amaurosis (LCA) is most often an autosomal recessive disorder. We report a father and son with autosomal dominant LCA due to a mutation in the CRX gene. DNA screening using an allele specific assay of 90 of the most common LCA-causing variations in the coding sequences of AIPL1, CEP290, CRB1, CRX, GUCY2D, RDH12 and RPE65 was performed on the father. Automated DNA sequencing of his son examining exon 3 of the CRX gene was subsequently performed. Both father and son have a heterozygous single base pair deletion of an adenine at codon 153 in the coding sequence of the CRX gene resulting in a frameshift mutation. Mutations involving the CRX gene may demonstrate an autosomal dominant inheritance pattern for LCA.

Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants.

PubMed

Farji-Brener, Alejandro G; Elizalde, Luciana; Fernández-Marín, Hermógenes; Amador-Vargas, Sabrina

2016-05-25

Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. © 2016 The Author(s).

Social life and sanitary risks: evolutionary and current ecological conditions determine waste management in leaf-cutting ants

PubMed Central

Farji-Brener, Alejandro G.; Elizalde, Luciana; Amador-Vargas, Sabrina

2016-01-01

Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. PMID:27226469

Variations in NPHP5 in Patients With Nonsyndromic Leber Congenital Amaurosis and Senior-Loken Syndrome

PubMed Central

Stone, Edwin M.; Cideciyan, Artur V.; Aleman, Tomas S.; Scheetz, Todd E.; Sumaroka, Alexander; Ehlinger, Mary A.; Schwartz, Sharon B.; Fishman, Gerald A.; Traboulsi, Elias I.; Lam, Byron L.; Fulton, Anne B.; Mullins, Robert F.; Sheffield, Val C.; Jacobson, Samuel G.

2014-01-01

Objective To investigate whether mutations in NPHP5 can cause Leber congenital amaurosis (LCA) without early-onset renal disease. Methods DNA samples from 276 individuals with non-syndromic LCA were screened for variations in the NPHP5 gene. Each had been previously screened for mutations in 8 known LCA genes without identifying a disease-causing genotype. Results Nine of the 276 LCA probands (3.2%) harbored 2 plausible disease-causing mutations (7 different alleles) in NPHP5. Four of these have been previously reported in patients with Senior-Loken syndrome (F141del, R461X, H506del, and R489X) and 3 are novel (A111del, E346X, and R455X). All 9 patients had severe visual loss from early childhood but none had overt renal disease in the first decade of life. Two patients were diagnosed with nephronophthisis in the second decade. Retinal imaging studies showed retained photoreceptor nuclei and retinal pigment epithelium integrity mainly in the cone-rich central retina, a phenotype with strong similarities to that of NPHP6 disease. Conclusions Mutations in NPHP5 can cause LCA without early-onset renal disease. Abnormalities observed in the photoreceptor outer segments (a cilial structure) may explain the severe visual loss in NPHP5-associated LCA. Clinical Relevance The persistence of central photoreceptor nuclei despite severe visual loss in NPHP5 disease is encouraging for future therapeutic interventions. PMID:21220633

Broadening GHG accounting with LCA: application to a waste management business unit.

PubMed

Fallaha, Sophie; Martineau, Geneviève; Bécaert, Valérie; Margni, Manuele; Deschênes, Louise; Samson, Réjean; Aoustin, Emmanuelle

2009-11-01

In an effort to obtain the most accurate climate change impact assessment, greenhouse gas (GHG) accounting is evolving to include life-cycle thinking. This study (1) identifies similarities and key differences between GHG accounting and life-cycle assessment (LCA), (2) compares them on a consistent basis through a case study on a waste management business unit. First, GHG accounting is performed. According to the GHG Protocol, annual emissions are categorized into three scopes: direct GHG emissions (scope 1), indirect emissions related to electricity, heat and steam production (scope 2) and other indirect emissions (scope 3). The LCA is then structured into a comparable framework: each LCA process is disaggregated into these three scopes, the annual operating activities are assessed, and the environmental impacts are determined using the IMPACT2002+ method. By comparing these two approaches it is concluded that both LCA and GHG accounting provide similar climate change impact results as the same major GHG contributors are determined for scope 1 emissions. The emissions from scope 2 appear negligible whereas emissions from scope 3 cannot be neglected since they contribute to around 10% of the climate change impact of the waste management business unit. This statement is strengthened by the fact that scope 3 generates 75% of the resource use damage and 30% of the ecosystem quality damage categories. The study also shows that LCA can help in setting up the framework for a annual GHG accounting by determining the major climate change contributors.

Evaluation of new alternatives in wastewater treatment plants based on dynamic modelling and life cycle assessment (DM-LCA).

PubMed

Bisinella de Faria, A B; Spérandio, M; Ahmadi, A; Tiruta-Barna, L

2015-11-01

With a view to quantifying the energy and environmental advantages of Urine Source-Separation (USS) combined with different treatment processes, five wastewater treatment plant (WWTP) scenarios were compared to a reference scenario using Dynamic Modelling (DM) and Life Cycle Assessment (LCA), and an integrated DM-LCA framework was thus developed. Dynamic simulations were carried out in BioWin(®) in order to obtain a realistic evaluation of the dynamic behaviour and performance of plants under perturbation. LCA calculations were performed within Umberto(®) using the Ecoinvent database. A Python™ interface was used to integrate and convert simulation data and to introduce them into Umberto(®) to achieve a complete LCA evaluation comprising foreground and background processes. Comparisons between steady-state and dynamic simulations revealed the importance of considering dynamic aspects such as nutrient and flow peaks. The results of the evaluation highlighted the potential of the USS scenario for nutrient recovery whereas the Enhanced Primary Clarification (EPC) scenario gave increased biogas production and also notably decreased aeration consumption, leading to a positive energy balance. Both USS and EPC scenarios also showed increased stability of plant operation, with smaller daily averages of total nitrogen and phosphorus. In this context, USS and EPC results demonstrated that the coupled USS + EPC scenario and its combinations with agricultural spreading of N-rich effluent and nitritation/anaerobic deammonification could present an energy-positive balance with respectively 27% and 33% lower energy requirements and an increase in biogas production of 23%, compared to the reference scenario. The coupled scenarios also presented lesser environmental impacts (reduction of 31% and 39% in total endpoint impacts) along with effluent quality well within the specified limits. The marked environmental performance (reduction of global warming) when nitrogen is used in agriculture shows the importance of future research on sustainable solutions for nitrogen recovery. The contribution analysis of midpoint impacts also showed hotspots that it will be important to optimize further, such as plant infrastructure and direct N2O emissions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of the effect of accounting method, IPCC v. LCA, on grass-based and confinement dairy systems' greenhouse gas emissions.

PubMed

O'Brien, D; Shalloo, L; Patton, J; Buckley, F; Grainger, C; Wallace, M

2012-09-01

Life cycle assessment (LCA) and the Intergovernmental Panel on Climate Change (IPCC) guideline methodology, which are the principal greenhouse gas (GHG) quantification methods, were evaluated in this study using a dairy farm GHG model. The model was applied to estimate GHG emissions from two contrasting dairy systems: a seasonal calving pasture-based dairy farm and a total confinement dairy system. Data used to quantify emissions from these systems originated from a research study carried out over a 1-year period in Ireland. The genetic merit of cows modelled was similar for both systems. Total mixed ration was fed in the Confinement system, whereas grazed grass was mainly fed in the grass-based system. GHG emissions from these systems were quantified per unit of product and area. The results of both methods showed that the dairy system that emitted the lowest GHG emissions per unit area did not necessarily emit the lowest GHG emissions possible for a given level of product. Consequently, a recommendation from this study is that GHG emissions be evaluated per unit of product given the growing affluent human population and increasing demand for dairy products. The IPCC and LCA methods ranked dairy systems' GHG emissions differently. For instance, the IPCC method quantified that the Confinement system reduced GHG emissions per unit of product by 8% compared with the grass-based system, but the LCA approach calculated that the Confinement system increased emissions by 16% when off-farm emissions associated with primary dairy production were included. Thus, GHG emissions should be quantified using approaches that quantify the total GHG emissions associated with the production system, so as to determine whether the dairy system was causing emissions displacement. The IPCC and LCA methods were also used in this study to simulate, through a dairy farm GHG model, what effect management changes within both production systems have on GHG emissions. The findings suggest that single changes have a small mitigating effect on GHG emissions (<5%), except for strategies used to control emissions from manure storage in the Confinement system (14% to 24%). However, when several management strategies were combined, GHG emissions per unit of product could be reduced significantly (15% to 30%). The LCA method was identified as the preferred approach to assess the effect of management changes on GHG emissions, but the analysis indicated that further standardisation of the approach is needed given the sensitivity of the approach to allocation decisions regarding milk and meat.

Life‐cycle and cost of goods assessment of fed‐batch and perfusion‐based manufacturing processes for mAbs

PubMed Central

Bunnak, Phumthep; Allmendinger, Richard; Ramasamy, Sri V.; Lettieri, Paola

2016-01-01

Life‐cycle assessment (LCA) is an environmental assessment tool that quantifies the environmental impact associated with a product or a process (e.g., water consumption, energy requirements, and solid waste generation). While LCA is a standard approach in many commercial industries, its application has not been exploited widely in the bioprocessing sector. To contribute toward the design of more cost‐efficient, robust and environmentally‐friendly manufacturing process for monoclonal antibodies (mAbs), a framework consisting of an LCA and economic analysis combined with a sensitivity analysis of manufacturing process parameters and a production scale‐up study is presented. The efficiency of the framework is demonstrated using a comparative study of the two most commonly used upstream configurations for mAb manufacture, namely fed‐batch (FB) and perfusion‐based processes. Results obtained by the framework are presented using a range of visualization tools, and indicate that a standard perfusion process (with a pooling duration of 4 days) has similar cost of goods than a FB process but a larger environmental footprint because it consumed 35% more water, demanded 17% more energy, and emitted 17% more CO2 than the FB process. Water consumption was the most important impact category, especially when scaling‐up the processes, as energy was required to produce process water and water‐for‐injection, while CO2 was emitted from energy generation. The sensitivity analysis revealed that the perfusion process can be made more environmentally‐friendly than the FB process if the pooling duration is extended to 8 days. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1324–1335, 2016 PMID:27390260

Life-cycle and cost of goods assessment of fed-batch and perfusion-based manufacturing processes for mAbs.

PubMed

Bunnak, Phumthep; Allmendinger, Richard; Ramasamy, Sri V; Lettieri, Paola; Titchener-Hooker, Nigel J

2016-09-01

Life-cycle assessment (LCA) is an environmental assessment tool that quantifies the environmental impact associated with a product or a process (e.g., water consumption, energy requirements, and solid waste generation). While LCA is a standard approach in many commercial industries, its application has not been exploited widely in the bioprocessing sector. To contribute toward the design of more cost-efficient, robust and environmentally-friendly manufacturing process for monoclonal antibodies (mAbs), a framework consisting of an LCA and economic analysis combined with a sensitivity analysis of manufacturing process parameters and a production scale-up study is presented. The efficiency of the framework is demonstrated using a comparative study of the two most commonly used upstream configurations for mAb manufacture, namely fed-batch (FB) and perfusion-based processes. Results obtained by the framework are presented using a range of visualization tools, and indicate that a standard perfusion process (with a pooling duration of 4 days) has similar cost of goods than a FB process but a larger environmental footprint because it consumed 35% more water, demanded 17% more energy, and emitted 17% more CO 2 than the FB process. Water consumption was the most important impact category, especially when scaling-up the processes, as energy was required to produce process water and water-for-injection, while CO 2 was emitted from energy generation. The sensitivity analysis revealed that the perfusion process can be made more environmentally-friendly than the FB process if the pooling duration is extended to 8 days. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1324-1335, 2016. © 2016 The Authors Biotechnology Progress published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers.

Life cycle based risk assessment of recycled materials in roadway construction.

PubMed

Carpenter, A C; Gardner, K H; Fopiano, J; Benson, C H; Edil, T B

2007-01-01

This paper uses a life-cycle assessment (LCA) framework to characterize comparative environmental impacts from the use of virgin aggregate and recycled materials in roadway construction. To evaluate site-specific human toxicity potential (HTP) in a more robust manner, metals release data from a demonstration site were combined with an unsaturated contaminant transport model to predict long-term impacts to groundwater. The LCA determined that there were reduced energy and water consumption, air emissions, Pb, Hg and hazardous waste generation and non-cancer HTP when bottom ash was used in lieu of virgin crushed rock. Conversely, using bottom ash instead of virgin crushed rock increased the cancer HTP risk due to potential leachate generation by the bottom ash. At this scale of analysis, the trade-offs are clearly between the cancer HTP (higher for bottom ash) and all of the other impacts listed above (lower for bottom ash). The site-specific analysis predicted that the contaminants (Cd, Cr, Se and Ag for this study) transported from the bottom ash to the groundwater resulted in very low unsaturated zone contaminant concentrations over a 200 year period due to retardation in the vadose zone. The level of contaminants predicted to reach the groundwater after 200 years was significantly less than groundwater maximum contaminant levels (MCL) set by the US Environmental Protection Agency for drinking water. Results of the site-specific contaminant release estimates vary depending on numerous site and material specific factors. However, the combination of the LCA and the site specific analysis can provide an appropriate context for decision making. Trade-offs are inherent in making decisions about recycled versus virgin material use, and regulatory frameworks should recognize and explicitly acknowledge these trade-offs in decision processes.

Comparative Human Health Impact Assessment of Engineered Nanomaterials in the Framework of Life Cycle Assessment.

PubMed

Fransman, Wouter; Buist, Harrie; Kuijpers, Eelco; Walser, Tobias; Meyer, David; Zondervan-van den Beuken, Esther; Westerhout, Joost; Klein Entink, Rinke H; Brouwer, Derk H

2017-07-01

For safe innovation, knowledge on potential human health impacts is essential. Ideally, these impacts are considered within a larger life-cycle-based context to support sustainable development of new applications and products. A methodological framework that accounts for human health impacts caused by inhalation of engineered nanomaterials (ENMs) in an indoor air environment has been previously developed. The objectives of this study are as follows: (i) evaluate the feasibility of applying the CF framework for NP exposure in the workplace based on currently available data; and (ii) supplement any resulting knowledge gaps with methods and data from the life cycle approach and human risk assessment (LICARA) project to develop a modified case-specific version of the framework that will enable near-term inclusion of NP human health impacts in life cycle assessment (LCA) using a case study involving nanoscale titanium dioxide (nanoTiO 2 ). The intent is to enhance typical LCA with elements of regulatory risk assessment, including its more detailed measure of uncertainty. The proof-of-principle demonstration of the framework highlighted the lack of available data for both the workplace emissions and human health effects of ENMs that is needed to calculate generalizable characterization factors using common human health impact assessment practices in LCA. The alternative approach of using intake fractions derived from workplace air concentration measurements and effect factors based on best-available toxicity data supported the current case-by-case approach for assessing the human health life cycle impacts of ENMs. Ultimately, the proposed framework and calculations demonstrate the potential utility of integrating elements of risk assessment with LCA for ENMs once the data are available. © 2016 Society for Risk Analysis.

Distributions of emissions intensity for individual beef cattle reared on pasture-based production systems.

PubMed

McAuliffe, G A; Takahashi, T; Orr, R J; Harris, P; Lee, M R F

2018-01-10

Life Cycle Assessment (LCA) of livestock production systems is often based on inventory data for farms typical of a study region. As information on individual animals is often unavailable, livestock data may already be aggregated at the time of inventory analysis, both across individual animals and across seasons. Even though various computational tools exist to consider the effect of genetic and seasonal variabilities in livestock-originated emissions intensity, the degree to which these methods can address the bias suffered by representative animal approaches is not well-understood. Using detailed on-farm data collected on the North Wyke Farm Platform (NWFP) in Devon, UK, this paper proposes a novel approach of life cycle impact assessment that complements the existing LCA methodology. Field data, such as forage quality and animal performance, were measured at high spatial and temporal resolutions and directly transferred into LCA processes. This approach has enabled derivation of emissions intensity for each individual animal and, by extension, its intra-farm distribution, providing a step towards reducing uncertainty related to agricultural production inherent in LCA studies for food. Depending on pasture management strategies, the total emissions intensity estimated by the proposed method was higher than the equivalent value recalculated using a representative animal approach by 0.9-1.7 kg CO 2 -eq/kg liveweight gain, or up to 10% of system-wide emissions. This finding suggests that emissions intensity values derived by the latter technique may be underestimated due to insufficient consideration given to poorly performing animals, whose emissions becomes exponentially greater as average daily gain decreases. Strategies to mitigate life-cycle environmental impacts of pasture-based beef productions systems are also discussed.

Identification of mutations in the AIPL1, CRB1, GUCY2D, RPE65, and RPGRIP1 genes in patients with juvenile retinitis pigmentosa.

PubMed

Booij, J C; Florijn, R J; ten Brink, J B; Loves, W; Meire, F; van Schooneveld, M J; de Jong, P T V M; Bergen, A A B

2005-11-01

To identify mutations in the AIPL1, CRB1, GUCY2D, RPE65, and RPGRIP1 genes in patients with juvenile retinitis pigmentosa. Mutation analysis was carried out in a group of 35 unrelated patients with juvenile autosomal recessive retinitis pigmentosa (ARRP), Leber's congenital amaurosis (LCA), or juvenile isolated retinitis pigmentosa (IRP), by denaturing high performance liquid chromatography followed by direct sequencing. All three groups of patients showed typical combinations of eye signs associated with retinitis pigmentosa: pale optic discs, narrow arterioles, pigmentary changes, and nystagmus. Mutations were found in 34% of in CRB1 (11%), GUCY2D (11%), RPE65 (6%), and RPGRIP1 (6%). Nine mutations are reported, including a new combination of two mutations in CRB1, and new mutations in GUCY2D and RPGRIP1. The new GUCY2D mutation (c.3283delC, p.Pro1069ArgfsX37) is the first pathological sequence change reported in the intracellular C-terminal domain of GUCY2D, and did not lead to the commonly associated LCA, but to a juvenile retinitis pigmentosa phenotype. The polymorphic nature of three previously described (pathological) sequence changes in AIPL1, CRB1, and RPGRIP1 was established. Seven new polymorphic changes, useful for further association studies, were found. New and previously described sequence changes were detected in retinitis pigmentosa in CRB1, GUCY2D, and RPGRIP1; and in LCA patients in CRB1, GUCY2D, and RPE65. These data, combined with previous reports, suggest that LCA and juvenile ARRP are closely related and belong to a continuous spectrum of juvenile retinitis pigmentosa.

Comparison of production-phase environmental impact metrics derived at the farm- and national-scale for United States agricultural commodities

NASA Astrophysics Data System (ADS)

Costello, Christine; Xue, Xiaobo; Howarth, Robert W.

2015-11-01

Agricultural production is critical for human survival and simultaneously contributes to ecosystem degradation. There is a need for transparent, rapid methods for evaluating the environmental impacts of agricultural production at the system-level in order to develop sustainable food supplies. We have developed a method for estimating the greenhouse gas (GHG), land use and reactive nitrogen inputs associated with the agricultural production phase of major crop and livestock commodities produced in the United States (US). Materials flow analysis (MFA) and life cycle assessment (LCA) techniques were applied to national inventory datasets. The net anthropogenic nitrogen inputs (NANI) toolbox served as the primary accounting tool for LCA and MFA. NANI was updated to create links between nitrogen fertilizer and nitrogen fixation associated with feed crops and animal food commodities. Results for the functional units kilogram (kg) of product and kg of protein for 2002 data fall within ranges of published LCA results from farm-scale studies across most metrics. Exceptions include eutrophication potential for milk and GHGs for chicken and eggs, these exceptions arise due to differing methods and boundary assumptions; suggestions for increasing agreement are identified. Land use for livestock commodities are generally higher than reported by other LCA studies due to the inclusion of all land identified as pasture or grazing land in the US in this study and given that most of the estimates from other LCAs were completed in Europe where land is less abundant. The method provides a view of the entire US agricultural system and could be applied to any year using publically available data. Additionally, utilizing a top-down approach reduces data collection and processing time making it possible to develop environmental inventory metrics rapidly for system-level decision-making.

A thematic review of life cycle assessment (LCA) applied to pig production

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

McAuliffe, Graham A., E-mail: g.a.mcauliffe@umail.ucc.ie; School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork; Chapman, Deborah V.

Commercial livestock production is known to have significant impacts on the environment. Pig production is a complex system which involves the production of animal feed, transportation, animal rearing and waste management. One tool for assessing the environmental performance of such complex systems is life cycle assessment (LCA). LCA has been applied to pig production considerably to date. This paper provides a chronological review of state-of-the-art pig production LCAs under three themes: feed production; entire-system livestock rearing; and waste management. The study considers how LCA applications have addressed technological improvements in animal husbandry, and highlights methodological limitations, particularly related to cross-studymore » comparisons. Recent research demonstrates crude protein reduction in feed and anaerobic treatment of pig excreta resulting in bioenergy production are the key targets for environmental performance improvements related to pig production. - Highlights: • An extensive review of LCA applied to pig production is provided chronologically over the past decade. • Individual studies have been categorised into feed, whole-system pig production and waste management themes. • We consider how LCAs have addressed state-of-the-art pig husbandry. • We offer a discussion on key findings, limitations and future research.« less

A Review of Environmental Life Cycle Assessments of Liquid Transportation Biofuels in the Pan American Region

NASA Astrophysics Data System (ADS)

Shonnard, David R.; Klemetsrud, Bethany; Sacramento-Rivero, Julio; Navarro-Pineda, Freddy; Hilbert, Jorge; Handler, Robert; Suppen, Nydia; Donovan, Richard P.

2015-12-01

Life-cycle assessment (LCA) has been applied to many biofuel and bioenergy systems to determine potential environmental impacts, but the conclusions have varied. Different methodologies and processes for conducting LCA of biofuels make the results difficult to compare, in-turn making it difficult to make the best possible and informed decision. Of particular importance are the wide variability in country-specific conditions, modeling assumptions, data quality, chosen impact categories and indicators, scale of production, system boundaries, and co-product allocation. This study has a double purpose: conducting a critical evaluation comparing environmental LCA of biofuels from several conversion pathways and in several countries in the Pan American region using both qualitative and quantitative analyses, and making recommendations for harmonization with respect to biofuel LCA study features, such as study assumptions, inventory data, impact indicators, and reporting practices. The environmental management implications are discussed within the context of different national and international regulatory environments using a case study. The results from this study highlight LCA methodology choices that cause high variability in results and limit comparability among different studies, even among the same biofuel pathway, and recommendations are provided for improvement.

Assessment of Effectiveness and Limitations of Habitat Suitability Models for Wetland Restoration

USGS Publications Warehouse

Draugelis-Dale, Rassa O.

2008-01-01

Habitat suitability index (HSI) models developed for wildlife in the Louisiana Coastal Area Comprehensive Ecosystem Restoration Plan (LCA study) have been assessed for parameter and overall model quality. The success of the suitability models from the South Florida Water Management District for The Everglades restoration project and from the Spatially Explicit Species Index Models (SESI) of the Across Trophic Level System Simulation (ATLSS) Program of Florida warranted investigation with possible application of modeling theory to the current LCA study. General HSI models developed by the U.S. Fish and Wildlife Service were also investigated. This report presents examinations of theoretical formulae and comparisons of the models, performed by using diverse hypothetical settings of hydrological/biological ecosystems to highlight weaknesses as well as strengths among the models, limited to the American alligator and selected wading bird species (great blue heron, great egret, and white ibis). Recommendations were made for the LCA study based on these assessments. An enhanced HSI model for the LCA study is proposed for the American alligator, and a new HSI model for wading birds is introduced for the LCA study. Performance comparisons of the proposed models with the other suitability models are made by using the aforementioned hypothetical settings.

A Review of Environmental Life Cycle Assessments of Liquid Transportation Biofuels in the Pan American Region.

PubMed

Shonnard, David R; Klemetsrud, Bethany; Sacramento-Rivero, Julio; Navarro-Pineda, Freddy; Hilbert, Jorge; Handler, Robert; Suppen, Nydia; Donovan, Richard P

2015-12-01

Life-cycle assessment (LCA) has been applied to many biofuel and bioenergy systems to determine potential environmental impacts, but the conclusions have varied. Different methodologies and processes for conducting LCA of biofuels make the results difficult to compare, in-turn making it difficult to make the best possible and informed decision. Of particular importance are the wide variability in country-specific conditions, modeling assumptions, data quality, chosen impact categories and indicators, scale of production, system boundaries, and co-product allocation. This study has a double purpose: conducting a critical evaluation comparing environmental LCA of biofuels from several conversion pathways and in several countries in the Pan American region using both qualitative and quantitative analyses, and making recommendations for harmonization with respect to biofuel LCA study features, such as study assumptions, inventory data, impact indicators, and reporting practices. The environmental management implications are discussed within the context of different national and international regulatory environments using a case study. The results from this study highlight LCA methodology choices that cause high variability in results and limit comparability among different studies, even among the same biofuel pathway, and recommendations are provided for improvement.

Life Cycle Environmental Impacts Resulting from the Manufacture of the Heliostat Field for a Reference Power Tower Design in the United States: Preprint

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

Heath, G.; Burkhardt, J.; Turchi, C.

2012-10-01

Life cycle assessment (LCA) is recognized as a useful analytical approach for quantifying environmental impacts of renewable energy technologies, including concentrating solar power (CSP). An LCA accounts for impacts from all stages in the development, operation, and decommissioning of a CSP plant, including such upstream stages as the extraction of raw materials used in system components, manufacturing of those components, and construction of the plant. The National Renewable Energy Laboratory is conducting a series of LCA studies for various CSP technologies. This paper contributes to a thorough LCA of a 100 MWnet molten salt power tower CSP plant by estimatingmore » the environmental impacts resulting from the manufacture of heliostats. Three life cycle metrics are evaluated: greenhouse gas emissions, water consumption, and cumulative energy demand. The heliostat under consideration (the 148 m2 Advanced Thermal Systems heliostat) emits 5,300 kg CO2eq, consumes 274 m3 of water, and requires 159,000 MJeq during its manufacture. Future work will incorporate the results from this study into the LCA model used to estimate the life cycle impacts of the entire 100 MWnet power tower CSP plant.« less

Estimating national forest carbon stocks and dynamics: combining models and remotely sensed information

NASA Astrophysics Data System (ADS)

Smallman, Thomas Luke; Exbrayat, Jean-François; Bloom, Anthony; Williams, Mathew

2017-04-01

Forests are a critical component of the global carbon cycle, storing significant amounts of carbon, split between living biomass and dead organic matter. The carbon budget of forests is the most uncertain component of the global carbon cycle - it is currently impossible to quantify accurately the carbon source/sink strength of forest biomes due to their heterogeneity and complex dynamics. It has been a major challenge to generate robust carbon budgets across landscapes due to data scarcity. Models have been used for estimating carbon budgets, but outputs have lacked an assessment of uncertainty, making a robust assessment of their reliability and accuracy challenging. Here a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC) data assimilation framework has been used to combine remotely sensed leaf area index (MODIS), biomass (where available) and deforestation estimates, in addition to forest planting information from the UK's national forest inventory, an estimate of soil carbon from the Harmonized World Database (HWSD) and plant trait information with a process model (DALEC) to produce a constrained analysis with a robust estimate of uncertainty of the UK forestry carbon budget between 2000 and 2010. Our analysis estimates the mean annual UK forest carbon sink at -3.9 MgC ha-1 yr-1 with a 95 % confidence interval between -4.0 and -3.1 MgC ha-1yr-1. The UK national forest inventory (NFI) estimates the mean UK forest carbon sink to be between -1.4 and -5.5 MgC ha-1 yr-1. The analysis estimate for total forest biomass stock in 2010 is estimated at 229 (177/232) TgC, while the NFI an estimated total forest biomass carbon stock of 216 TgC. Leaf carbon area (LCA) is a key plant trait which we are able to estimate using our analysis. Comparison of median estimates for (LCA) retrieved from the analysis and a UK land cover map show higher and lower values for LCA are estimated areas dominated by needle leaf and broad leaf forests forest respectively, consistent with ecological expectations. Moreover, LCA is positively and negatively correlated with leaf-life span and allocation of photosynthate to foliage respectively, supported by field observations. This emergence of key plant traits and correlations between traits increases our confidence in the robustness of this analysis. Furthermore, this framework also allows us to search for additional emergent properties from the analysis such as spatial variation of retrieved drought tolerance. Finally our analysis is able to identify components of the carbon cycle with the largest uncertainty e.g. allocation of photosynthate to wood and wood residence times, providing targets for future observations (e.g. ESA's BIOMASS mission). Our Bayesian analysis system is ideally suited for assimilation of multiple biomass estimates and their associated uncertainties to reduce both the overall analysis uncertainty and bias in estimates biomass stocks.

Verification of the lack of correlation between age and longitudinal chromatic aberrations of the human eye from the visible to the infrared

PubMed Central

Nakajima, Masashi; Hiraoka, Takahiro; Hirohara, Yoko; Oshika, Tetsuro; Mihashi, Toshifumi

2015-01-01

Several researchers studied the longitudinal chromatic aberration (LCA) of the human eye and observed that it does not change due to age. We measured the LCA of 45 subjects’ normal right eyes at three distinct wavelengths (561, 690, and 840 nm) using a Hartmann–Shack wavefront aberrometer (HSWA) while consecutively switching between three light sources for wavefront sensing. We confirmed that the LCA of the human eye does not change due to age between 22 and 57 years. PMID:26203391

Current Research in Land Use Impact Assessment

EPA Science Inventory

There is a continuing debate on how to best evaluate land use impacts within the LCA framework. While this problem is spatially and temporally complex, recent advances in tool development are providing options to allow a GIS-based analysis of various ecosystem services given the...

Autonomous learning in gesture recognition by using lobe component analysis

NASA Astrophysics Data System (ADS)

Lu, Jian; Weng, Juyang

2007-02-01

Gesture recognition is a new human-machine interface method implemented by pattern recognition(PR).In order to assure robot safety when gesture is used in robot control, it is required to implement the interface reliably and accurately. Similar with other PR applications, 1) feature selection (or model establishment) and 2) training from samples, affect the performance of gesture recognition largely. For 1), a simple model with 6 feature points at shoulders, elbows, and hands, is established. The gestures to be recognized are restricted to still arm gestures, and the movement of arms is not considered. These restrictions are to reduce the misrecognition, but are not so unreasonable. For 2), a new biological network method, called lobe component analysis(LCA), is used in unsupervised learning. Lobe components, corresponding to high-concentrations in probability of the neuronal input, are orientation selective cells follow Hebbian rule and lateral inhibition. Due to the advantage of LCA method for balanced learning between global and local features, large amount of samples can be used in learning efficiently.

Eco-innovative design approach: Integrating quality and environmental aspects in prioritizing and solving engineering problems

NASA Astrophysics Data System (ADS)

Chakroun, Mahmoud; Gogu, Grigore; Pacaud, Thomas; Thirion, François

2014-09-01

This study proposes an eco-innovative design process taking into consideration quality and environmental aspects in prioritizing and solving technical engineering problems. This approach provides a synergy between the Life Cycle Assessment (LCA), the nonquality matrix, the Theory of Inventive Problem Solving (TRIZ), morphological analysis and the Analytical Hierarchy Process (AHP). In the sequence of these tools, LCA assesses the environmental impacts generated by the system. Then, for a better consideration of environmental aspects, a new tool is developed, the non-quality matrix, which defines the problem to be solved first from an environmental point of view. The TRIZ method allows the generation of new concepts and contradiction resolution. Then, the morphological analysis offers the possibility of extending the search space of solutions in a design problem in a systematic way. Finally, the AHP identifies the promising solution(s) by providing a clear logic for the choice made. Their usefulness has been demonstrated through their application to a case study involving a centrifugal spreader with spinning discs.

Lentiviral Expression of Retinal Guanylate Cyclase-1 (RetGC1) Restores Vision in an Avian Model of Childhood Blindness

PubMed Central

Haire, Shannon E; Aleman, Tomas S; Cideciyan, Artur V; Sokal, Izabel; Palczewski, Krzysztof; Jacobson, Samuel G; Semple-Rowland, Susan L

2006-01-01

Background Leber congenital amaurosis (LCA) is a genetically heterogeneous group of retinal diseases that cause congenital blindness in infants and children. Mutations in the GUCY2D gene that encodes retinal guanylate cyclase–1 (retGC1) were the first to be linked to this disease group (LCA type 1 [LCA1]) and account for 10%–20% of LCA cases. These mutations disrupt synthesis of cGMP in photoreceptor cells, a key second messenger required for function of these cells. The GUCY1*B chicken, which carries a null mutation in the retGC1 gene, is blind at hatching and serves as an animal model for the study of LCA1 pathology and potential treatments in humans. Methods and Findings A lentivirus-based gene transfer vector carrying the GUCY2D gene was developed and injected into early-stage GUCY1*B embryos to determine if photoreceptor function and sight could be restored to these animals. Like human LCA1, the avian disease shows early-onset blindness, but there is a window of opportunity for intervention. In both diseases there is a period of photoreceptor cell dysfunction that precedes retinal degeneration. Of seven treated animals, six exhibited sight as evidenced by robust optokinetic and volitional visual behaviors. Electroretinographic responses, absent in untreated animals, were partially restored in treated animals. Morphological analyses indicated there was slowing of the retinal degeneration. Conclusions Blindness associated with loss of function of retGC1 in the GUCY1*B avian model of LCA1 can be reversed using viral vector-mediated gene transfer. Furthermore, this reversal can be achieved by restoring function to a relatively low percentage of retinal photoreceptors. These results represent a first step toward development of gene therapies for one of the more common forms of childhood blindness. PMID:16700630

Evaluation de l'incertitude d'un modele d'analyse de cycle de vie temporel de la production et de la consommation de l'electricite dans un contexte de gestion des centres de donnees

NASA Astrophysics Data System (ADS)

Vallee Schmitter, Constant

As part of a research program focused on finding ways to decrease the environnemental impacts of data center, the CIRAIG developed two models in order to be able to select the province with the cleanest electricity. Even if both models use the life cycle analysis methodology (LCA) they differ on their approach. The first model is based on attributional LCA and the second one on consequential LCA. However the last step of an LCA, as recommended by the ISO, is to evaluate the uncertainty of the results. This step was left aside in the previous studies to be the main subject of this research. The goal of this research is to improve the trust in the those models by doing uncertainty analysis on the results they produced. This analysis was split into four parts: 1) compute the distributions of the grid mix used by the two studies; 2) compute the consequences of those distributions on the decisions; 3) quantify the differences between the data sources and evaluate their consequences on the decisions; 4) identify and quantify the power plants not included in the data sources and evaluate their contribution on the grid-mixes. To fulfil those goals, scripts were written to compute Monte-Carlo simulations of the environnemental impacts of the multiple grid-mix used in the models for the tree provinces. Data about the electric production have been collected to identify previously not accounted for power plants. Comparisons of the data sources used in the original studies were carry out to evaluate the significance of the disparities. Finally a model of the electric grid of Ontario was implemented in a power system simulation software. This was to show the importance of some of the physical constraints inside the network. The result of this study show that the uncertainty included in the results have little to no consequences on the decision process for the studied provinces. This two new models, implemented to take into account the temporal aspect of electric consumption of electricity on the environmental impacts, are a real improvement to the previous static models.

Participatory approach, acceptability and transparency of waste management LCAs: case studies of Torino and Cuneo.

PubMed

Blengini, Gian Andrea; Fantoni, Moris; Busto, Mirko; Genon, Giuseppe; Zanetti, Maria Chiara

2012-09-01

The paper summarises the main results obtained from two extensive applications of Life Cycle Assessment (LCA) to the integrated municipal solid waste management systems of Torino and Cuneo Districts in northern Italy. Scenarios with substantial differences in terms of amount of waste, percentage of separate collection and options for the disposal of residual waste are used to discuss the credibility and acceptability of the LCA results, which are adversely affected by the large influence of methodological assumptions and the local socio-economic constraints. The use of site-specific data on full scale waste treatment facilities and the adoption of a participatory approach for the definition of the most sensible LCA assumptions are used to assist local public administrators and stakeholders showing them that LCA can be operational to waste management at local scale. Copyright © 2012 Elsevier Ltd. All rights reserved.

Environmental impact assessment as a complement of life cycle assessment. Case study: Upgrading of biogas.

PubMed

Morero, Betzabet; Rodriguez, María B; Campanella, Enrique A

2015-08-01

This work presents a comparison between an environmental impact assessment (EIA) and a life cycle assessment (LCA) using a case study: upgrading of biogas. The upgrading of biogas is studied using three solvents: water, physical solvent and amine. The EIA follows the requirements of the legislation of Santa Fe Province (Argentina), and the LCA follows ISO 14040. The LCA results showed that water produces a minor impact in most of the considered categories whereas the high impact in the process with amines is the result of its high energy consumptions. The positive results obtained in the EIA (mainly associated with the cultural and socioeconomic components) make the project feasible and all the negative impacts can be mitigated by preventive and remedial measures. From the strengths and weaknesses of each tool, it is inferred that the EIA is a procedure that can complement the LCA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimating national forest carbon stocks and dynamics: combining models and remotely sensed information

NASA Astrophysics Data System (ADS)

Smallman, Luke; Williams, Mathew

2016-04-01

Forests are a critical component of the global carbon cycle, storing significant amounts of carbon, split between living biomass and dead organic matter. The carbon budget of forests is the most uncertain component of the global carbon cycle - it is currently impossible to quantify accurately the carbon source/sink strength of forest biomes due to their heterogeneity and complex dynamics. It has been a major challenge to generate robust carbon budgets across landscapes due to data scarcity. Models have been used but outputs have lacked an assessment of uncertainty, making a robust assessment of their reliability and accuracy challenging. Here a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC) data assimilation framework has been used to combine remotely sensed leaf area index (MODIS), biomass (where available) and deforestation estimates, in addition to forest planting and clear-felling information from the UK's national forest inventory, an estimate of soil carbon from the Harmonized World Database (HWSD) and plant trait information with a process model (DALEC) to produce a constrained analysis with a robust estimate of uncertainty of the UK forestry carbon budget between 2000 and 2010. Our analysis estimates the mean annual UK forest carbon sink at -3.9 MgC ha-1yr-1 with a 95 % confidence interval between -4.0 and -3.1 MgC ha-1 yr-1. The UK national forest inventory (NFI) estimates the mean UK forest carbon sink to be between -1.4 and -5.5 MgC ha-1 yr-1. The analysis estimate for total forest biomass stock in 2010 is estimated at 229 (177/232) TgC, while the NFI an estimated total forest biomass carbon stock of 216 TgC. Leaf carbon area (LCA) is a key plant trait which we are able to estimate using our analysis. Comparison of median estimates for LCA retrieved from the analysis and a UK land cover map show higher and lower values for LCA are estimated areas dominated by needle leaf and broad leaf forests forest respectively, consistent with ecological expectations. Moreover, the retrieved LCA is positively correlated with leaf-life span and negatively correlated with allocation of photosynthate to foliage, supported by field observations. This emergence of key plant traits and correlations between traits increases our confidence in the robustness of this analysis. Furthermore, this framework also allows us to search for additional emergent properties from the analysis such as spatial variation of retrieved drought tolerance. Finally our analysis is able to identify components of the carbon cycle with the largest uncertainty providing targets for future observations (e.g. remotely sensed biomass). Our Bayesian analysis system is ideally suited for assimilation of multiple biomass estimates and their associated uncertainties to reduce both uncertainty in the state of the system but also process parameters (e.g. wood residence time).

Cost optimisation and minimisation of the environmental impact through life cycle analysis of the waste water treatment plant of Bree (Belgium).

PubMed

De Gussem, K; Wambecq, T; Roels, J; Fenu, A; De Gueldre, G; Van De Steene, B

2011-01-01

An ASM2da model of the full-scale waste water plant of Bree (Belgium) has been made. It showed very good correlation with reference operational data. This basic model has been extended to include an accurate calculation of environmental footprint and operational costs (energy consumption, dosing of chemicals and sludge treatment). Two optimisation strategies were compared: lowest cost meeting the effluent consent versus lowest environmental footprint. Six optimisation scenarios have been studied, namely (i) implementation of an online control system based on ammonium and nitrate sensors, (ii) implementation of a control on MLSS concentration, (iii) evaluation of internal recirculation flow, (iv) oxygen set point, (v) installation of mixing in the aeration tank, and (vi) evaluation of nitrate setpoint for post denitrification. Both an environmental impact or Life Cycle Assessment (LCA) based approach for optimisation are able to significantly lower the cost and environmental footprint. However, the LCA approach has some advantages over cost minimisation of an existing full-scale plant. LCA tends to chose control settings that are more logic: it results in a safer operation of the plant with less risks regarding the consents. It results in a better effluent at a slightly increased cost.

Eco-Efficient Process Improvement at the Early Development Stage: Identifying Environmental and Economic Process Hotspots for Synergetic Improvement Potential.

PubMed

Piccinno, Fabiano; Hischier, Roland; Seeger, Stefan; Som, Claudia

2018-05-15

We present here a new eco-efficiency process-improvement method to highlight combined environmental and costs hotspots of the production process of new material at a very early development stage. Production-specific and scaled-up results for life cycle assessment (LCA) and production costs are combined in a new analysis to identify synergetic improvement potentials and trade-offs, setting goals for the eco-design of new processes. The identified hotspots and bottlenecks will help users to focus on the relevant steps for improvements from an eco-efficiency perspective and potentially reduce their associated environmental impacts and production costs. Our method is illustrated with a case study of nanocellulose. The results indicate that the production route should start with carrot pomace, use heat and solvent recovery, and deactivate the enzymes with bleach instead of heat. To further improve the process, the results show that focus should be laid on the carrier polymer, sodium alginate, and the production of the GripX coating. Overall, the method shows that the underlying LCA scale-up framework is valuable for purposes beyond conventional LCA studies and is applicable at a very early stage to provide researchers with a better understanding of their production process.

Impacts from urban water systems on receiving waters - How to account for severe wet-weather events in LCA?

PubMed

Risch, Eva; Gasperi, Johnny; Gromaire, Marie-Christine; Chebbo, Ghassan; Azimi, Sam; Rocher, Vincent; Roux, Philippe; Rosenbaum, Ralph K; Sinfort, Carole

2018-01-01

Sewage systems are a vital part of the urban infrastructure in most cities. They provide drainage, which protects public health, prevents the flooding of property and protects the water environment around urban areas. On some occasions sewers will overflow into the water environment during heavy rain potentially causing unacceptable impacts from releases of untreated sewage into the environment. In typical Life Cycle Assessment (LCA) studies of urban wastewater systems (UWS), average dry-weather conditions are modelled while wet-weather flows from UWS, presenting a high temporal variability, are not currently accounted for. In this context, the loads from several storm events could be important contributors to the impact categories freshwater eutrophication and ecotoxicity. In this study we investigated the contributions of these wet-weather-induced discharges relative to average dry-weather conditions in the life cycle inventory for UWS. In collaboration with the Paris public sanitation service (SIAAP) and Observatory of Urban Pollutants (OPUR) program researchers, this work aimed at identifying and comparing contributing flows from the UWS in the Paris area by a selection of routine wastewater parameters and priority pollutants. This collected data is organized according to archetypal weather days during a reference year. Then, for each archetypal weather day and its associated flows to the receiving river waters (Seine), the parameters of pollutant loads (statistical distribution of concentrations and volumes) were determined. The resulting inventory flows (i.e. the potential loads from the UWS) were used as LCA input data to assess the associated impacts. This allowed investigating the relative importance of episodic wet-weather versus "continuous" dry-weather loads with a probabilistic approach to account for pollutant variability within the urban flows. The analysis at the scale of one year showed that storm events are significant contributors to the impacts of freshwater eutrophication and ecotoxicity compared to those arising from treated effluents. At the rain event scale the wet-weather contributions to these impacts are even more significant, accounting for example for up to 62% of the total impact on freshwater ecotoxicity. This also allowed investigating and discussing the ecotoxicity contribution of each class of pollutants among the broad range of inventoried substances. Finally, with such significant contributions of pollutant loads and associated impacts from wet-weather events, further research is required to better include temporally-differentiated emissions when evaluating eutrophication and ecotoxicity. This will provide a better understanding of how the performance of an UWS system affects the receiving environment for given local weather conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

An approach to holistically assess (dairy) farm eco-efficiency by combining Life Cycle Analysis with Data Envelopment Analysis models and methodologies.

PubMed

Soteriades, A D; Faverdin, P; Moreau, S; Charroin, T; Blanchard, M; Stott, A W

2016-11-01

Eco-efficiency is a useful guide to dairy farm sustainability analysis aimed at increasing output (physical or value added) and minimizing environmental impacts (EIs). Widely used partial eco-efficiency ratios (EIs per some functional unit, e.g. kg milk) can be problematic because (i) substitution possibilities between EIs are ignored, (ii) multiple ratios can complicate decision making and (iii) EIs are not usually associated with just the functional unit in the ratio's denominator. The objective of this study was to demonstrate a 'global' eco-efficiency modelling framework dealing with issues (i) to (iii) by combining Life Cycle Analysis (LCA) data and the multiple-input, multiple-output production efficiency method Data Envelopment Analysis (DEA). With DEA each dairy farm's outputs and LCA-derived EIs are aggregated into a single, relative, bounded, dimensionless eco-efficiency score, thus overcoming issues (i) to (iii). A novelty of this study is that a model providing a number of additional desirable properties was employed, known as the Range Adjusted Measure (RAM) of inefficiency. These properties altogether make RAM advantageous over other DEA models and are as follows. First, RAM is able to simultaneously minimize EIs and maximize outputs. Second, it indicates which EIs and/or outputs contribute the most to a farm's eco-inefficiency. Third it can be used to rank farms in terms of eco-efficiency scores. Thus, non-parametric rank tests can be employed to test for significant differences in terms of eco-efficiency score ranks between different farm groups. An additional DEA methodology was employed to 'correct' the farms' eco-efficiency scores for inefficiencies attributed to managerial factors. By removing managerial inefficiencies it was possible to detect differences in eco-efficiency between farms solely attributed to uncontrollable factors such as region. Such analysis is lacking in previous dairy studies combining LCA with DEA. RAM and the 'corrective' methodology were demonstrated with LCA data from French specialized dairy farms grouped by region (West France, Continental France) and feeding strategy (regardless of region). Mean eco-efficiency score ranks were significantly higher for farms with 30% maize in the total forage area before correcting for managerial inefficiencies. Mean eco-efficiency score ranks were higher for West than Continental farms, but significantly higher only after correcting for managerial inefficiencies. These results helped identify the eco-efficiency potential of each region and feeding strategy and could therefore aid advisors and policy makers at farm or region/sector level. The proposed framework helped better measure and understand (dairy) farm eco-efficiency, both within and between different farm groups.

Two-step sensitivity testing of parametrized and regionalized life cycle assessments: methodology and case study.

PubMed

Mutel, Christopher L; de Baan, Laura; Hellweg, Stefanie

2013-06-04

Comprehensive sensitivity analysis is a significant tool to interpret and improve life cycle assessment (LCA) models, but is rarely performed. Sensitivity analysis will increase in importance as inventory databases become regionalized, increasing the number of system parameters, and parametrized, adding complexity through variables and nonlinear formulas. We propose and implement a new two-step approach to sensitivity analysis. First, we identify parameters with high global sensitivities for further examination and analysis with a screening step, the method of elementary effects. Second, the more computationally intensive contribution to variance test is used to quantify the relative importance of these parameters. The two-step sensitivity test is illustrated on a regionalized, nonlinear case study of the biodiversity impacts from land use of cocoa production, including a worldwide cocoa products trade model. Our simplified trade model can be used for transformable commodities where one is assessing market shares that vary over time. In the case study, the highly uncertain characterization factors for the Ivory Coast and Ghana contributed more than 50% of variance for almost all countries and years examined. The two-step sensitivity test allows for the interpretation, understanding, and improvement of large, complex, and nonlinear LCA systems.

Assessing eco-efficiency: A metafrontier directional distance function approach using life cycle analysis

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

Beltrán-Esteve, Mercedes, E-mail: mercedes.beltran@uv.es; Reig-Martínez, Ernest; Estruch-Guitart, Vicent

Sustainability analysis requires a joint assessment of environmental, social and economic aspects of production processes. Here we propose the use of Life Cycle Analysis (LCA), a metafrontier (MF) directional distance function (DDF) approach, and Data Envelopment Analysis (DEA), to assess technological and managerial differences in eco-efficiency between production systems. We use LCA to compute six environmental and health impacts associated with the production processes of nearly 200 Spanish citrus farms belonging to organic and conventional farming systems. DEA is then employed to obtain joint economic-environmental farm's scores that we refer to as eco-efficiency. DDF allows us to determine farms' globalmore » eco-efficiency scores, as well as eco-efficiency scores with respect to specific environmental impacts. Furthermore, the use of an MF helps us to disentangle technological and managerial eco-inefficiencies by comparing the eco-efficiency of both farming systems with regards to a common benchmark. Our core results suggest that the shift from conventional to organic farming technology would allow a potential reduction in environmental impacts of 80% without resulting in any decline in economic performance. In contrast, as regards farmers' managerial capacities, both systems display quite similar mean scores.« less

Clustering of adolescent health concerns: a latent class analysis of school students in New Zealand.

PubMed

Noel, Hannah; Denny, Simon; Farrant, Bridget; Rossen, Fiona; Teevale, Tasileta; Clark, Terryann; Fleming, Terry; Bullen, Pat; Sheridan, Janie; Fortune, Sarah

2013-11-01

The aims of this study are to identify clinically meaningful groups of adolescents based on their engagement in high levels of risk behaviours or severe emotional health concerns and to describe the demographic characteristics of these groups in two populations of school students in New Zealand. A nationally representative sample of secondary school students was surveyed in 2007; alternative education (AE) students in Auckland and Northland were surveyed in 2009. A total of 9107 secondary school students and 335 AE students completed a youth health questionnaire using Internet tablets. Latent class analysis (LCA) was used to identify groups of students on the basis of distinct profiles of their risk behaviours and mental health concerns. The majority (80%) of students in secondary schools are 'healthy' and report few health concerns, 16% are considered 'risky' or 'distressed', and 4% report 'multiple' risk behaviour profiles or emotional health concerns. In AE, only 21% of students were considered 'healthy' with most featuring in the 'risky' or 'multiple' groups. Females were more likely to be 'distressed', whereas males were more likely to feature in the 'risky' or 'multiple' groups. Clinically-concerning health risk behaviours and emotional health concerns 'cluster' in up to 20% of students in secondary schools and up to 79% of students in AE. Gender, ethnic and socio-economic disparities are also observed. This highlights the importance of comprehensive psychosocial assessment and appropriate service provision, particularly for at-risk groups. © 2013 The Authors. Journal of Paediatrics and Child Health © 2013 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Set organic pollution as an impact category to achieve more comprehensive evaluation of life cycle assessment in wastewater-related issues.

PubMed

Zhao, Xinyue; Yang, Jixian; Ma, Fang

2018-02-01

For wastewater-related issues (WRI), life cycle assessment (LCA) is often used to evaluate environmental impacts and derive optimization strategies. To promote the application of LCA for WRI, it is critical to incorporate local impact of water pollutants. Organic pollution, a main type of water pollution, has not been given much consideration in current LCA systems. This paper investigates the necessity of setting a regionalized impact category to reflect the local impact of organic pollution. A case study is conducted concerning an upgraded wastewater treatment plant (WWTP) in China, which is assumed to meet different sewage control strategies. Chemical oxygen demand (COD) is selected to represent the organic pollution and treated as an individual impact category. CML 2002 is used to quantify the environmental impacts of different strategies. Results show that abnormal LCA results are generated with the traditional eutrophication impact category, and after the introduction of COD, more reasonable LCA results are obtained, making the entire comparison of different control strategies more meaningful and compelling. Moreover, BEES, Ecovalue 08, and Chinese factors are adopted here as different weighting methods. Different weighting results exhibited various trade-offs for the increasingly strict control strategies; the results of BEES and Ecovalue08 underlined the potential environmental burden, but the results of Chinese factors only emphasized the local environmental improvement. It is concluded that setting regionalized impact category for organic pollution can make LCA results more reasonable in wastewater treatment, especially in evaluating Chinese cases because of the serious water pollution caused by large quantities of COD emission.

Holistic Analysis of the Urban Water Systems in Greater Cincinnati Region

EPA Science Inventory

Urban water and wastewater systems with two utilities in Greater Cincinnati region were evaluated as a case study to elucidates a bigger picture of a typical centralized urban water system. Two different integrated assessment metrics were used to analyze the same system. LCA an...

LCA and Cost Analysis of Membrane Bioreactor Systems: Influence of Scale, Population Density, Climate, and Methane Recovery

EPA Science Inventory

Future changes in drinking and waste water infrastructure need to incorporate a holistic view of the water service sustainability tradeoffs and potential benefits when considering shifts towards new treatment technology, decentralized systems, energy recovery and reuse of treated...

Worldwide Life Cycle Analysis (LCA) of Greenhouse Gas (GHG) Emissions from Petroleum Jet Fuel

DOT National Transportation Integrated Search

2017-11-09

The main objective of this project was to calculate greenhouse gas emissions estimates for petroleum jet fuels for the recent past and for future scenarios in the coming decades. Results were reported globally and broken out by world regions, and the...

FRAMEWORK FOR ENVIRONMENTAL DECISION-MAKING, FRED: A TOOL FOR ENVIRONMENTALLY-PREFERABLE PURCHASING

EPA Science Inventory

In support of the Environmentally Preferable Purchasing Program of the US EPA, the Systems Analysis Branch has developed a decision-making tool based on life cycle assessment. This tool, the Framework for Responsible Environmental Decision-making or FRED streamlines LCA by choosi...

CRITICAL ANALYSIS OF THE MATHEMATICAL RELATIONSHIPS AND COMPREHENSIVENESS OF LIFE CYCLE IMPACT ASSESSMENT APPROACHES

EPA Science Inventory

The impact assessment phase of Life Cycle Assessment (LCA) has received much criticism due to lack of consistency. ISO 14042 requires selection of impact categories that “reflect a comprehensive set of environmental issues” related to the system being studied, especi...