Detection of Aliphatically Bridged Multi-Core Polycyclic Aromatic Hydrocarbons in Sooting Flames with Atmospheric-Sampling High-Resolution Tandem Mass Spectrometry.

This paper provides experimental evidence for the chemical structures of aliphatically substituted and bridged polycyclic aromatic hydrocarbon (PAH) species in gas-physe combustion environments. The identification of these single- and multicore aromatic species, which have been hypothesized to be important in PAH growth and soot nucleation, was made possible through a combination of sampling gaseous constituents from an atmospheric pressure inverse coflow diffusion flame of ethylene and high-resolution tandem mass spectrometry (MS-MS). In these experiments, the flame-sampled components were ionized using a continuous VUV lamp at 10.0 eV and the ions were subsequently fragmented through collisions with Ar atoms in a collision-induced dissociation (CID) process. The resulting fragment ions, which were separated using a reflectron time-of-flight mass spectrometer, were used to extract structural information about the sampled aromatic compounds. The high-resolution mass spectra revealed the presence of alkylated single-core aromatic compounds and the fragment ions that were observed correspond to the loss of saturated and unsaturated units containing up to a total of 6 carbon atoms. Furthermore, the aromatic structures that form the foundational building blocks of the larger PAHs were identified to be smaller single-ring and pericondensed aromatic species with repetitive structural features. For demonstrative purposes, details are provided for the CID of molecular ions at masses 202 and 434. Insights into the role of the aliphatically substituted and bridged aromatics in the reaction network of PAH growth chemistry were obtained from spatially resolved measurements of the flame. The experimental results are consistent with a growth mechanism in which alkylated aromatics are oxidized to form pericondensed ring structures or react and recombine with other aromatics to form larger, potentially three-dimensional, aliphatically bridged multicore aromatic hydrocarbons

Sensitivity of a real-time PCR method for the detection of transgenes in a mixture of transgenic and non-transgenic seeds of papaya (\u3cem\u3eCarica papaya\u3c/em\u3e L.)

Background Genetically engineered (GE) ringspot virus-resistant papaya cultivars ‘Rainbow’ and ‘SunUp’ have been grown in Hawai’i for over 10 years. In Hawai’i, the introduction of GE papayas into regions where non-GE cultivars are grown and where feral non-GE papayas exist have been accompanied with concerns associated with transgene flow. Of particular concern is the possibility of transgenic seeds being found in non-GE papaya fruits via cross-pollination. Development of high-throughput methods to reliably detect the adventitious presence of such transgenic material would benefit both the scientific and regulatory communities. Results We assessed the accuracy of using conventional qualitative polymerase chain reaction (PCR) as well as real-time PCR-based assays to quantify the presence of transgenic DNA from bulk samples of non-GE papaya seeds. In this study, an optimized method of extracting high quality DNA from dry seeds of papaya was standardized. A reliable, sensitive real-time PCR method for detecting and quantifying viral coat protein (cp) transgenes in bulk seed samples utilizing the endogenous papain gene is presented. Quantification range was from 0.01 to 100 ng/μl of GE-papaya DNA template with a detection limit as low as 0.01% (10 pg). To test this system, we simulated transgene flow using known quantities of GE and non-GE DNA and determined that 0.038% (38 pg) GE papaya DNA could be detected using real-time PCR. We also validated this system by extracting DNA from known ratios of GE seeds to non-GE seeds of papaya followed by real-time PCR detection and observed a reliable detection limit of 0.4%. Conclusions This method for the quick and sensitive detection of transgenes in bulked papaya seed lots using conventional as well as real-time PCR-based methods will benefit numerous stakeholders. In particular, this method could be utilized to screen selected fruits from maternal non-GE papaya trees in Hawai’i for the presence of transgenic seed at typical regulatory threshold levels. Incorporation of subtle differences in primers and probes for variations in cp worldwide should allow this method to be utilized elsewhere when and if deregulation of transgenic papaya occurs

Stem cell tourism and spinal cord injury in South Africa

Background. The publicity around stem cell therapy has given many persons who have sustained a devastating injury such as spinal cord injury (SCI) the hope of achieving partial or full recovery from their injuries. Several phase I and II clinical trials are being conducted owing to positive results obtained in animal models. While safety during the trials has been demonstrated, clinical efficacy in the outcome of ethically approved trials is still lacking. Many persons affected by SCI are, however, desperate for a cure and are lured into undergoing stem cell therapy by marketing campaigns and information readily available on the internet. These people travel far and wide to undergo stem cell therapy, which has led to the term ‘stem cell tourism’. Objectives. To compare the data from participants’ self-report questionnaires before and after their stem cell therapy to determine if there were differences in their functional and neurological status, and to record details of the procedures. Method. Persons who sustained a SCI and who received apparent stem cell therapy in South Africa (SA) or elsewhere were recruited to participate in the present study. Volunteers who gave written informed consent were asked to complete a biographical questionnaire and validated self-report questionnaire (Spinal Cord Independence Measure version III (SCIM III)) before and after their stem cell therapy to determine if there were differences in their functional and neurological status. The results of the self-report questionnaires were compared with the published expected functional outcome of people with lesions at a similar level of SCI to the participants. The secondary aims of the study were to document details of the procedures and their locations, the sources of ‘stem cells’ and the cost. Results. There was no indication that the participants’ functional outcomes, as measured by the self-reported SCIM III, were better than the expected level of functional ability in patients with similar injury levels. Likewise, the neurological motor recovery scored on the International Standards for the Neurological Classification of Spinal Cord Injury (ISNCSCI) motor scores showed no improvement post stem cell therapy. Conclusion. This study highlights the need to curb the practice of offering unethical and non-evidence-based stem cell therapy for SCI. Ethical research and treatment is encouraged as well as an effective legal framework and education of health professionals, patients and their family members and caregivers, which will avoid unrealistic expectations, bogus therapies and the potential adverse effects of non-evidence-based ‘stem cell therapies’ offered by clinics via the internet

Analysis of Transaction Management Performance

There is currently much interest in incorporating transactions into both operating systems and general purpose programming languages. This paper provides a detailed examination of the design and performance of the“¢ transaction manager of the Camelot system. Camelot is a transaction facility that provides a rich model of transactions intended to support a wide variety of general-purpose applications. The transaction manager's principal function is to execute the protocols that ensure atomicity. The conclusions of this study are: a simple optimization to two-phase commit reduces logging activity of distributed transactions; non-blocking commit is practical for some applications; multithreaded design improves throughput provided that log batching is used; multi-casting reduces the variance of distributed commit protocols in a LAN environment; and the performance of transaction mechanisms such as Camelot depend heavily upon kernel performance

PTSD symptoms and cortisol stress reactivity in adolescence: Findings from a high adversity cohort in South Africa

BACKGROUND: Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is implicated in the pathophysiology of post-traumatic stress disorder (PTSD). However, there has been little study of HPA stress reactivity in association with PTSD symptoms (PTSS) in children; and there is limited research on PTSD in low and middle-income countries, where trauma exposure is more common and co-occurring stressors more likely. METHOD: We assessed the relationship between PTSS and cortisol stress reactivity in children aged 13 years (N = 291) from an impoverished South African community. HPA axis stress reactivity was indexed by salivary cortisol during the Trier Social Stress Test (TSST). RESULTS: In regression analyses both trauma exposure and PTSS showed small inverse associations with total cortisol output (area under the curve with respect to ground) during the TSST, but PTSS effects did not withstand correction for covariates. In addition, hierarchical linear modelling (HLM) found that PTSS were associated with alterations in the shape of the profile of cortisol reactivity that were moderated by sex. In girls, PTSS were associated with reduced linear slope but larger quadratic slopes, whereas the opposite pattern was found in boys. Thus, elevated PTSS were associated with overall blunted profiles of cortisol stress reactivity in girls, but a larger quadratic slope in boys reflects a steeper cortisol increase and decline in boys. There was no relationship between trauma exposure (with or without PTSS) and cortisol reactivity profiles in HLM analyses. CONCLUSION: In children from a high adversity, low and middle income country context, sex specific associations were found between PTSS and cortisol responses to psychosocial stress. Further research should probe HPA axis functioning more comprehensively in such populations to understand the biological associations of PTSS

A Business Plan for The Fitzgerald Institute

This piece seeks to develop a business strategy for the University of Akron\u27s Fitzgerald Institute for Entrepreneurship. The recommendations given were developed utilizing research on entrepreneurial education and the desires of students at the university

Depression, anxiety, and psychological distress among caregivers of young children in rural Lesotho: Associations with food insecurity, household death and parenting stress

Good mental health is a critical resource for mothers and caregivers of young children, given the central role of mental health in enabling responsive caregiving. However, fulfilling caregiving responsibilities under challenging circumstances such as extreme poverty, food insecurity, and gender inequality intensifies vulnerability to poor mental health. Previous research focuses on mental health of mothers, while in many LMICs children are cared for by other caregivers, such as grandparents. We examined the prevalence of mental health problems among primary caregivers of young children in rural Lesotho, and investigated factors associated with these mental health problems. We analysed baseline data from a cluster randomised controlled trial, where all caregivers with children between 1 and 5 years old across 34 villages were invited to participate. The analysis included mental health data from 781 caregivers of 998 children. We assessed caregiver mental health using three self-report screening instruments. Univariate and multivariate regression modelling tested associations between caregiver, child and household variables and (1) depression symptoms (PHQ-9), (2) anxiety symptoms (GAD-7), (3) psychological distress (SRQ-20), (4) suicidal ideation and (5) help-seeking for mental health. This study reported a high prevalence of symptoms of psychological distress (46.2%), depression (25.7%), anxiety (17.1%) and suicidal ideation (27.5%) among caregivers. Greater prevalence was associated with food insecurity, parenting stress or recent death in the family/household. Older caregivers reported higher rates of psychological distress and depression, while younger caregivers reported higher rates of anxiety. Suicidal ideation was associated with greater food insecurity and parenting stress, and lower caregiver education. Our findings support the need to address intersecting public health issues to improve conditions for caregivers in these settings. Targeting modifiable risk factors such as food insecurity among individuals within a society who carry disproportionate burdens of caregiving should be prioritised, especially in contexts of scarcity, where mental health is not prioritised

Characterization of Spray A flame structure for parametric variations in ECN constant-volume vessels using chemiluminescence and laser-induced fluorescence

The transient and quasi-steady flame structure of reacting fuel sprays produced by single-hole injectors has been studied using chemiluminescence imaging and Planar Laser-Induced Fluorescence (PLIF) in various constant-volume facilities at different research institutes participating in the Engine Combustion Network (ECN). The evolution of the high-temperature flame has been followed based on chemiluminescence imaging of the excited-state hydroxyl radical (OH*), and PLIF of ground-state OH. Regions associated with low-temperature chemical reactions are visualized using formaldehyde (CH2O) PLIF with 355-nm excitation. We compare the results obtained by different research institutes under nominally identical experimental conditions and fuel injectors. In spite of design differences among the various experimental facilities, the results are consistent. This lends confidence to studies of transient behavior and parameter variations performed by individual research groups. We present results of the transient flame structures at Spray A reference conditions, and include parametric variations around this baseline, involving ambient temperature, oxygen concentration and injection pressure. Key results are the observed influence of an entrainment wave on the transient flame behavior, model-substantiated explanations for the high-intensity OH* lobes at the lift-off length and differences with OH PLIF, and a general analogy of the flame structures with a spray cone along which the flame tends to locate for the applied parametric variations

Food Should not be Forgotten: Impacts of Combined Cash Transfer Receipt and Food Security on Child Education and Cognition in South Africa and Malawi.

Social protection can take many forms. Both cash transfers and food security may have important contributions to child cognitive development. This study examines the potential impact of combinations of cash transfers and food security status on child cognitive development and educational outcomes. Cross-sectional data for 796 HIV-affected children in the Child Community Care study were utilised for this analysis. Children and caregivers completed interview schedules comprised of standardised items on socio-demographics, household data, cash grant receipt and food security status, school achievement, and cognition. A series of logistic and linear regression models and marginal effects analyses were undertaken to explore the impacts of differing levels of social protection (none; either cash grant receipt or food secure status or, both in combination) on child educational and cognitive outcomes. Although all children lived in poverty-stricken households, 20% (157/796) of children did not live in a household in receipt of a cash grant and did not report food security; 32.4% (258/796) reported either component of social protection and, 47.9% (381/796) received both measures of social protection in combination. Compared to no social protection, being in receipt of either component of social protection was found to be significantly associated with being in the correct class for age, higher scores of non-verbal cognition, and higher working memory scores. Receiving both social protection measures in combination was found to be significantly associated with reduced educational risk scores, improved odds of being in the correct class for age, regular school attendance, missing less than a week of school in the previous two weeks, higher scores on measures of nonverbal cognition, higher working memory scores, and learning new things more easily. Educational and cognitive outcomes for children can be bolstered by social protection measures (cash grant receipt or food security). Benefits are enhanced when social protection is received in combination. Such findings support the notion of synergistic social protection responses for children living in environments impacted by high levels of HIV burden and deprivation