Petroleomic Analysis of Bio-oils from the Fast Pyrolysis of Biomass: Laser Desorption Ionization−Linear Ion Trap−Orbitrap Mass Spectrometry Approach

Fast pyrolysis of biomass produces bio-oils that can be upgraded into biofuels. Despite similar physical properties to petroleum, the chemical properties of bio-oils are quite different and their chemical compositions, particularly those of non-volatile compounds, are not well-known. Here, we report the first time attempt at analyzing bio-oils using high-resolution mass spectrometry (MS), which employed laser desorption ionization−linear ion trap−Orbitrap MS. Besides a few limitations, we could determine chemical compositions for over 100 molecular compounds in a bio-oil sample produced from the pyrolysis of a loblolly pine tree. These compounds consist of 3−6 oxygens and 9−17 double-bond equivalents (DBEs). Among those, O4 compounds with a DBE of 9−13 were most abundant. Unlike petroleum oils, the lack of nearby molecules within a ±2 Da mass window for major components enabled clear isolation of precursor ions for subsequent MS/MS structural investigations. Petroleomic analysis and a comparison to low-mass components in hydrolytic lignin suggest that they are dimers and trimers of depolymerized lignin

Diverse microbial communities hosted by the model carnivorous pitcher plant Sarracenia purpurea: analysis of both bacterial and eukaryotic composition across distinct host plant populations

Background. The pitcher plant Sarracenia purpurea supplements nutrient acquisition through carnivory, capturing insect prey which are digested by a food web community of eukaryotes and bacteria. While the food web invertebrates are well studied, and some recent studies have characterized bacteria, detailed genetic analysis of eukaryotic diversity is lacking. This study aimed to compare eukaryotic and bacterial composition and diversity of pitcher communities within and between populations of host plants in nearby but distinct wetland habitats, and to characterize microbial functions across populations and in comparison with another freshwater community. Methods. Pitcher fluid was sampled from the two wetlands, Cedarburg and Sapa Bogs, community DNA was extracted, and 16S and 18S rRNA amplicons were sequenced and data processed for community-level comparisons. Results and Conclusions. Bacterial diversity in the small pitcher volume rivaled that of larger aquatic communities. Between pitcher plant populations, several bacterial families (Kiloniellaceae, Acetobacteraceae, Xanthobacteraceae, Sanguibacteraceae, Oligoflexaceae, Nitrosomonadaceae, Chromatiaceae, Saprospiraceae) were significantly higher in one population. However, although predicted pitcher bacterial functions were distinct from other freshwater communities, especially for some amino acid metabolism, functions were similar across all the pitchers in the two populations. This suggests some functional redundancy among bacterial taxa, and that functions converge to achieve similar food web processes. The sequencing identified a previously under- appreciated high diversity of ciliates, Acari mites, fungi and flagellates in pitcher com- munities; the most abundant sequences from eukaryotic taxa were Oligohymenophorea ciliates, millipedes and Ichthyosporea flagellates. Two thirds of taxa were identified as food web inhabitants and less than one third as prey organisms. Although eukaryotic composition was not significantly different between populations, there were different species of core taxonomic groups present in different pitchers--these differences may be driven by wetland habitats providing different populations to colonize new pitchers. Eukaryotic composition was more variable than bacterial composition, and there was a poor relationship between bacterial and eukaryotic composition within individual pitchers, suggesting that colonization by eukaryotes may be more stochastic than for How to bacteria, and bacterial recruitment to pitchers may involve factors other than prey capture and colonization by eukaryotic food web inhabitants

High-Resolution Mass Spectrometric Characterization of Molecules on Biochar from Pyrolysis and Gasification of Switchgrass

Organic molecules entrapped in biochar during pyrolysis and gasification of switchgrass have been studied using high-resolution mass spectrometry. Two solvent systems, toluene and a mixture of water/methanol, were used to extract hydrophobic aromatic compounds and hydrophilic polar compounds, respectively. Laser desorption ionization and atmospheric pressure photoionization were used for toluene extracts, while electrospray ionization was used for water/methanol extracts, followed by orbitrap mass spectrometric data acquisition. Molecular compounds previously known in bio-oils were observed for fast pyrolysis biochar, with phenolic and carbohydrate-derived compounds originating from the pyrolysis of lignin and holocellulose, respectively. In contrast, polycyclic aromatic hydrocarbons (PAHs) with various ring sizes were observed for gasification biochar and also for slow pyrolysis biochar in low abundance

Gas Chromatography-High Resolution Tandem Mass Spectrometry Using a GC-APPI-LIT Orbitrap for Complex Volatile Compounds Analysis

A new approach of volatile compounds analysis is proposed using a linear ion trap Orbitrap mass spectrometer coupled with gas chromatography through an atmospheric pressure photoionization interface. In the proposed GC-HRMS/MS approach, direct chemical composition analysis is made for the precursor ions in high resolution MS spectra and the structural identifications were made through the database search of high quality MS/MS spectra. Successful analysis of a complex perfume sample was demonstrated and compared with GC-EI-Q and GC-EI-TOF. The current approach is complementary to conventional GC-EI-MS analysis and can identify low abundance co-eluting compounds. Toluene co-sprayed as a dopant through API probe significantly enhanced ionization of certain compounds and reduced oxidation during the ionization

Bio-oil Analysis Using Negative Electrospray Ionization: Comparative Study of High-Resolution Mass Spectrometers and Phenolic versus Sugaric Components

We have previously demonstrated that a petroleomic analysis could be performed for bio-oils and revealed the complex nature of bio-oils for the nonvolatile phenolic compounds (Smith, E.;Lee, Y. J. Energy Fuels 2010, 24, 5190−5198). As a subsequent study, we have adapted electrospray ionization in negative-ion mode to characterize a wide variety of bio-oil compounds. A comparative study of three common high-resolution mass spectrometers was performed to validate the methodology and to investigate the differences in mass discrimination and resolution. The mass spectrum is dominated by low mass compounds with m/z of 100–250, with some compounds being analyzable by gas chromatography–mass spectrometry (GC–MS). We could characterize over 800 chemical compositions, with only about 40 of them being previously known in GC–MS. This unveiled a much more complex nature of bio-oils than typically shown by GC–MS. The pyrolysis products of cellulose and hemicellulose, particularly polyhydroxy cyclic hydrocarbons (or what we call “sugaric” compounds), such as levoglucosan, could be effectively characterized with this approach. Phenolic compounds from lignin pyrolysis could be clearly distinguished in a contour map of double bond equivalent (DBE) versus the number of carbons from these sugaric compounds

An Examination of Factors that Support Sustainable Cultural and Curricular Change in STEM Teaching and Learning

Using a mixed-methods design, this body of work from the SUMMIT-P consortium explores possible effective conditions for the sustainable reform of STEM teaching and learning at the collegiate level. A model of catalysts for successful and sustainable change is proposed, based on five years of data collection and observations. These catalysts include institutional support, intrinsic and extrinsic motivation of faculty involved, measures of student success, institution size, prior faculty experience, faculty buy-in, and institutional culture. The discussion ends with a delve into the potential broader impacts of this work. For example, this model may help institutions better understand how to implement curricular change more effectively

Evaluating a Large-Scale Multi-Institution Project: Challenges Faced and Lessons Learned

SUMMIT-P consists of nine participating institutions working toward common goals but from unique perspectives. Evaluating such a large-scale project with diverse stakeholders has presented challenges. For one, evaluation on this scale necessitates a team effort rather than a single evaluator. Communication is key among the evaluators as well as among the project players at large. Participation and reliable, timely feedback from participants are perhaps the most important issues while also posing some of our greatest challenges. We present strategies we developed to counteract these challenges. In particular, we discuss the development of an assessment tracking system used to not only monitor responses but to also promote an increase in on-time responses. We conclude with a discussion of some lessons learned about evaluating large-scale, multi-site projects to share with other evaluators and PIs alike

Engaging school leaders, empowering voices, & exposing strengths : lived experiences of the discipline gap and school-to-prison pipeline.

This capstone project includes three distinct studies that explore issues of race, discipline and education. Existing literature underscores the over disciplining of students of Color. Research indicates programs like Positive Behavior Interventions and Supports (PBIS) are successful in decreasing disproportionate discipline for minority students in urban schools. No studies have addressed urban school leaders make sense of PBIS within the racialized context of their schools. The purpose of the first study is to explore ways principals make sense of PBIS policy in the racial context of their schools. This study also explores the role of racialized discourses in principal Sensemaking of the racialized context. A collective multiple case study was conducted applying Critical Race Theory (CRT) and Sensemaking Theory (ST) as a way to understand principals’ cognition and action regarding disproportionate discipline in their schools. Data was collected through interviews, district data analysis, and document analysis. Results were interpreted using CRT and ST tenets. Findings indicated that two types of Sensemaking of policy and racialized discourses were exhibited by participants. Five priority areas were identified as implications for research, policy, and practice. The following two studies address race, discipline, and education in regards to the experiences of black girls. The plight of black boys (e.g. high suspensions and drop-outs) has galvanized philanthropic efforts where private and public funding resources have prioritized black males without consideration for the black girls. The second study will add to the limited research on the experiences and perceptions of urban middle school black girls in the school-to-prison pipeline literature. The purpose of this study is to explore perceptions of urban, public school discipline by middle school black girls who are suspended from school. Greater insight into black girls’ perspectives of discipline experiences could prepare better designed learning environments and educational experiences that will help decrease the disproportionate discipline gap. Inquiry into adolescent black girl’s perceptions of discipline centers a student voice in why and how students are pushed from, or jump out of, urban public schools. The final study fills a gap in the literature examining disproportionate discipline in regards to Black girls focusing on the strengths of this population to challenge negative conceptions. The purpose of this study is to discover the strengths of Black girls who have been persistently disciplined in high school. This study was framed as an embedded case study applying the Appreciative Inquiry (AI) process in interviews and observations to gain insights into what inspires persistently disciplined Black girls to continue in education. The results incorporate the first two stages of AI: discover and dream. The researcher discovers core strengths of three Black girls within the conceptual framework of Strengths in Communities of Color: trust, love, spirituality, and resistance. After analyzing the data, this framework was revised to include independence as an additional strength. These strengths were considered in dreaming what is possible in research, policy, and practice

Examining the influence of extrinsic factors on herbivore assemblage composition in a southern African savanna

Globally, herbivore populations have become threatened by the effects of a growing human population. This has resulted in over-hunting, habitat encroachment, fragmentation and degradation and competition leading to the replacement of wild herbivore populations with livestock. African herbivores, in particular, have experienced a severe decline in abundance and distribution, and vast conservation management efforts are underway to preserve herbivore populations and promote their growth. However, conservation management efforts sometimes have unintended consequences on the abundance and distribution of herbivores as a result of the complex interactions they have with their ecosystem. The aim of this study was to: 1) examine the drivers of herbivore distribution at the Satara section of Kruger National Park (hereafter ‘KNP’) at a landscape scale, to determine assemblage composition under the constraints of different environmental attributes; and 2) examine feeding selection by grazing herbivores of different morpho-physiological characteristics at a patch scale of differing environmental attributes. To achieve this, thirty-six experimental plots were established at three distances from water at Satara, and manipulated by mowing, mowing and fertilising or fertilising only over the course of a year, to account for seasonal effects. Each plot was fitted with a camera trap which ran for five weeks in each sampling season, and the data collected focussed on eleven herbivore species of differing body size, digestive strategy and feeding preference. These species were selected due to their abundance at Satara, and their representation of a variety of morpho-physiological characteristics. To achieve both aims, generalised linear models were used to determine the probability of occurrence of a functional type (for aim 1- Chapter 3), and individual species (for aim 2- Chapter 4). To construct the generalised linear models for Chapter 3, hypotheses about species’ relative distribution and abundance were developed through a literature review of forage and water availability constraints on feeding preference and body size of herbivore biomass at a landscape scale. I expected strong seasonal relationships between vegetation biomass and quality, and biomass of water-dependent herbivores with increasing distance to water. My analyses of herbivore distribution across the region confirmed broad-scale descriptions of interactions between forage requirements and water availability, across a set of species which differ in functional traits, at a landscape scale. In Chapter 4, trends in probability of occurrence by seven grazing herbivore species were determined using camera trap data at a patch scale. My results showed that season was a major determinant of species distribution, especially those which are not obligate grazers or feed exclusively in the 0.5 km to 2 km zone from water. I found that most selective feeding occurred in the late wet season when water would be more evenly distributed across the landscape and forage resources close to water would have had the chance to recover from depletion as a result of dry season use. The collective efforts of this study show that distance from water was a critical determinant of herbivore distribution across the landscape, and that forage utilisation by small mixed-feeders and large grazers in particular, altered significantly across seasons. This has important implications for the provision of artificial water, given that foraging pressure is increased closer to water. Landscape heterogeneity needs to be maintained through efficient water provision, to allow areas of forage reserve to maintained in the dry season, where species are constrained by water availability and forage quality and quantity