Biology Commons^™

Comprehensive Phylogenetic Reconstruction Of Amoebozoa Based On Concatenated Analyses Of Ssu-Rdna And Actin Genes, Daniel J.G. Lahr, Jessica Grant, Truc Nguyen, Jian Hua Lin, Laura A. Katz

Biological Sciences: Faculty Publications

Evolutionary relationships within Amoebozoa have been the subject of controversy for two reasons: 1) paucity of morphological characters in traditional surveys and 2) haphazard taxonomic sampling in modern molecular reconstructions. These along with other factors have prevented the erection of a definitive system that resolves confidently both higher and lower-level relationships. Additionally, the recent recognition that many protosteloid amoebae are in fact scattered throughout the Amoebozoa suggests that phylogenetic reconstructions have been excluding an extensive and integral group of organisms. Here we provide a comprehensive phylogenetic reconstruction based on 139 taxa using molecular information from both SSU-rDNA and actin genes. …

Tubulin Tyrosine Ligase-Like Genes Ttll3 And Ttll6 Maintain Zebrafish Cilia Structure And Motility, Narendra Pathak, Christina A. Austin, Iain A. Drummond

Neuroscience: Faculty Publications

Tubulin post-translational modifications generate microtubule heterogeneity and modulate microtubule function, and are catalyzed by tubulin tyrosine ligase-like (TTLL) proteins. Using antibodies specific to monoglycylated, polyglycylated, and glutamylated tubulin in whole mount immunostaining of zebrafish embryos, we observed distinct, tissue-specific patterns of tubulin modifications. Tubulin modification patterns in cilia correlated with the expression of ttll3 and ttll6 in ciliated cells. Expression screening of all zebrafish tubulin tyrosine ligase-like genes revealed additional tissue-specific expression of ttll1 in brain neurons, ttll4 in muscle, and ttll7 in otic placodes. Knockdown of ttll3 eliminated cilia tubulin glycylation but had surprisingly mild effects on cilia structure …

Evolution Of The Actin Gene Family In Testate Lobose Amoebae (Arcellinida) Is Characterized By Two Distinct Clades Of Paralogs And Recent Independent Expansions, Daniel J.G. Lahr, Truc B. Nguyen, Erika Barbero, Laura A. Katz

Biological Sciences: Faculty Publications

The evolution of actin gene families is characterized by independent expansions and contractions across the eukaryotic tree of life. Here, we assess diversity of actin gene sequences within three lineages of the genus Arcella, a free-living testate (shelled) amoeba in the Arcellinida. We established four clonal lines of two morphospecies, Arcella hemisphaerica and A. vulgaris, and assessed their phylogenetic relationship within the "Amoebozoa" using small subunit ribosomal DNA (SSU-rDNA) genealogy. We determined that the two lines of A. hemisphaerica are identical in SSU-rDNA, while the two A. vulgaris are independent genetic lineages. Furthermore, we characterized multiple actin gene copies from …

Skeletal Muscle Gender Dimorphism From Proteomics, Kalina Dimova, Lauren Ann Metskas, Mohini Kulp, Stylianos P. Scordilis

Biological Sciences: Faculty Publications

Gross contraction in skeletal muscle is primarily determined by a relatively small number of contractile proteins, however this tissue is also remarkably adaptable to environmental factors such as hypertrophy by resistance exercise and atrophy by disuse. It thereby exhibits remodeling and adaptations to stressors (heat, ischemia, heavy metals, etc.). Damage can occur to muscle by a muscle exerting force while lengthening, the so-called eccentric contraction. The contractile proteins can be damaged in such exertions and need to be repaired, degraded and/or resynthesized; these functions are not part of the contractile proteins, but of other much less abundant proteins in the …

On The Nature Of Species: Insights From Paramecium And Other Ciliates, Meaghan S. Hall, Laura A. Katz

Biological Sciences: Faculty Publications

The multiple species concepts currently in use by the scientific community (e. g. Morphological, Biological, Phylogenetic) are united in that they all aim to capture the process of divergence between populations. For example, the Biological Species Concept defines a species as a natural group of organisms that is reproductively isolated from other such groups. Here we synthesize nearly a century of research on the ciliate genus Paramecium that highlights the shortcomings of our prevailing notions on the nature of species. In this lineage, there is discordance between morphology, mating behavior, and genetics, features assumed to be correlated, at least after …

Expanding Character Sampling For Ciliate Phylogenetic Inference Using Mitochondrial Ssu-Rdna As A Molecular Marker, Micah Dunthorn, Wilhelm Foissner, Laura A. Katz

Biological Sciences: Faculty Publications

Molecular systematics of ciliates, particularly at deep nodes, has largely focused on increasing taxon sampling using the nuclear small subunit rDNA (nSSU-rDNA) locus. These previous analyses have generally been congruent with morphologically-based classifications, although there is extensive non-monophyly at many levels. However, caution is needed in interpreting these results as nSSU-rDNA is just a single molecular marker. Here the mitochondrial small subunit rDNA (mtSSU-rDNA) is evaluated for deep ciliate nodes using the Colpodea as an example. Overall, well-supported nodes in the mtSSU-rDNA and concatenated topologies are well supported in the nSSU-rDNA topology; e.g., the non-monophyly of the Cyrtolophosidida. The two …

Genome Dynamics Are Influenced By Food Source In Allogromia Laticollaris Strain Csh (Foraminifera), Laura Wegener Parfrey, Laura A. Katz

Biological Sciences: Faculty Publications

Across the eukaryotic tree of life, genomes vary within populations and within individuals during their life cycle. Understanding intraspecific genome variation in diverse eukaryotes is key to elucidating the factors that underlie this variation. Here, we characterize genome dynamics during the life cycle of Allogromia laticollaris strain CSH, a member of the Foraminifera, using fluorescence microscopy and reveal extensive variation in nuclear size and DNA content. Both nuclear size and DNA content are tightly correlated across a 700-fold range in cell volume. In contrast to models in yeast where nuclear size is determined solely by cell size, the relationship in …

Neural Activity Patterns In Response To Interspecific And Intraspecific Variation In Mating Calls In The Túngara Frog, Mukta Chakraborty, Lisa A. Mangiamele, Sabrina S. Burmeister

Biological Sciences: Faculty Publications

Background: During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus) can produce single note calls (whines) and multi-note calls (whine-chucks). While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice. Methodology/Principal Findings: To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of …

Broadly Sampled Multigene Analyses Yield A Well-Resolved Eukaryotic Tree Of Life, Laura Wegener Parfrey, Jessica Grant, Yonas I. Tekle, Erica Lasek-Nesselquist, Hilary G. Morrison, Mitchell L. Sogin, David J. Patterson, Laura A. Katz

Biological Sciences: Faculty Publications

An accurate reconstruction of the eukaryotic tree of life is essential to identify the innovations underlying the diversity of microbial and macroscopic (e.g., plants and animals) eukaryotes. Previous work has divided eukaryotic diversity into a small number of high-level "supergroups," many of which receive strong support in phylogenomic analyses. However, the abundance of data in phylogenomic analyses can lead to highly supported but incorrect relationships due to systematic phylogenetic error. Furthermore, the paucity of major eukaryotic lineages (19 or fewer) included in these genomic studies may exaggerate systematic error and reduce power to evaluate hypotheses. Here, we use a taxon-rich …

Essential Genes For Astroglial Development And Axon Pathfinding During Zebrafish Embryogenesis, Michael J.F. Barresi, Sean Burton, Kristina Dipietrantonio, Adam Amsterdam, Nancy Hopkins, Rolf O. Karlstrom

Biological Sciences: Faculty Publications

The formation of the central nervous system depends on the coordinated development of neural and glial cell types that arise from a common precursor. Using an existing group of zebrafish mutants generated by viral insertion, we performed a "shelf-screen" to identify genes necessary for astroglial development and axon scaffold formation. We screened 274 of 315 viral insertion lines using antibodies that label axons (anti-Acetylated Tubulin) and astroglia (anti-Gfap) and identified 25 mutants with defects in gliogenesis, glial patterning, neurogenesis, and axon guidance. We also identified a novel class of mutants affecting radial glial cell numbers. Defects in astroglial patterning were …

Gender Dimorphism In The Exercise-Naïve Murine Skeletal Muscle Proteome, Lauren Ann Metskas, Mohini Kulp, Stylianos P. Scordilis

Biological Sciences: Faculty Publications

Skeletal muscle is a plastic tissue with known gender dimorphism, especially at the metabolic level. A proteomic comparison of male and female murine biceps brachii was undertaken, resolving an average of 600 protein spots of MW 15–150 kDa and pI 5–8. Twenty-six unique full-length proteins spanning 11 KOG groups demonstrated statistically significant (p<0.05) abundance differences between genders; the majority of these proteins have metabolic functions. Identified glycolytic enzymes demonstrated decreased abundance in females, while abundance differences in identified oxidative phosphorylation enzymes were specific to the proteins rather than to the functional group as a whole. Certain cytoskeletal and stress proteins showed specific expression differences, and all three phosphorylation states of creatine kinase showed significant decreased abundance in females. Expression differences were significant but many were subtle (≤ 2-fold), and known hormonally-regulated proteins were not identified. We conclude that while gender dimorphism is present in non-exercised murine skeletal muscle, the proteome comparison of male and female biceps brachii in exercise-naive mice indicates subtle differences rather than a large or obviously hormonal dimorphism.

Alternative Processing Of Scrambled Genes Generates Protein Diversity In The Ciliate Chilodonella Uncinata, Laura A. Katz, Alexandra M. Kovner

Biological Sciences: Faculty Publications

In ciliates, chromosomal rearrangements occur during the development of the somatic macronuclear genome from the germline micronuclear genome. These rearrangements are extensive in three ciliate classes-Armophorea, Spirotrichea, and Phyllopharyngea-generating a macronucleus with up to 20,000,000 gene-sized chromosomes. Earlier, we have shown that these three classes also share elevated rates of protein evolution relative to other ciliates. To assess the evolution of germline-limited sequences in the class Phyllopharyngea, we used a combination of traditional and walking PCR to analyze micronuclear copies of multiple genes from two lines of the morphospecies Chilodonella uncinata for which we had previously characterized macronuclear sequences. Analyses …

Diversity Of Oligotrichia And Choreotrichia Ciliates In Coastal Marine Sediments And In Overlying Plankton, Mary Doherty, Maiko Tamura, Jan A.C. Vriezen, George B. Mcmanus, Laura A. Katz

Biological Sciences: Faculty Publications

Elucidating the relationship between ciliate communities in the benthos and the plankton is critical to understanding ciliate diversity in marine systems. Although data for many lineages are sparse, at least some members of the dominant marine ciliate clades Oligotrichia and Choreotrichia can be found in both plankton and benthos, in the latter either as cysts or active forms. In this study, we developed a molecular approach to address the relationship between the diversity of ciliates in the plankton and those of the underlying benthos in the same locations. Samples from plankton and sediments were compared across three sites along the …

A Community-Based Study Of Factors Associated With Continuing Transmission Of Lymphatic Filariasis In Leogane, Haiti, Alexis Boyd, Kimberly Y. Won, Shannon K. Mcclintock, Catherine V. Donovan, Sandra J. Laney, Steven A. Williams, Nils Pilotte, Thomas G. Streit, Madsen V.E. Beau De Rochars, Patrick J. Lammie

Biological Sciences: Faculty Publications

Seven rounds of mass drug administration (MDA) have been administered in Leogane, Haiti, an area hyperendemic for lymphatic filariasis (LF). Sentinel site surveys showed that the prevalence of microfilaremia was reduced to ,1% from levels as high as 15.5%, suggesting that transmission had been reduced. A separate 30-cluster survey of 2- to 4-year-old children was conducted to determine if MDA interrupted transmission. Antigen and antifilarial antibody prevalence were 14.3% and 19.7%, respectively. Follow-up surveys were done in 6 villages, including those selected for the cluster survey, to assess risk factors related to continued LF transmission and to pinpoint hotspots of …

Detection Of Wuchereria Bancrofti L3 Larvae In Mosquitoes: A Reverse Transcriptase Pcr Assay Evaluating Infection And Infectivity, Sandra J. Laney, Reda M.R. Ramzy, Hanan H. Helmy, Hoda A. Farid, Ameen A. Ashour, Gary J. Weil, Steven A. Williams

Biological Sciences: Faculty Publications

Lymphatic filariasis is a disabling and disfiguring disease caused by a parasite that is transmitted by a mosquito. The life cycle of the parasite requires two hosts: the mosquito vector and the human host. Part of the developmental life cycle of the parasite occurs in the mosquito and the other part in the human host. The parasite develops through four stages in the mosquito, only the last of which is infectious to humans. The third larval stage (L3) is the infective stage that initiates human infections when infective mosquitoes bite humans. There is currently a global program attempting to eliminate …

Dynamic Genomes Of Eukaryotes And The Maintenance Of Genomic Integrity, Laura Wegener Parfrey, Laura A. Katz

Biological Sciences: Faculty Publications

Many biologists assume that eukaryotic genomes are transmitted stably between generations with only minor variations. Yet, this presumed constancy is at odds with data indicating that eukaryotic genomes are dynamic, varying extensively in content among many different lineages. Thus, rather than being constant, genomes vary considerably within individuals during their lifetimes.

Gender Dimorphism In The Exercise-Naïve Murine Skeletal Muscle Proteome, Lauren Ann Metskas, Mohini Kulp, Stylianos P. Scordilis

Biological Sciences: Faculty Publications

Skeletal muscle is a plastic tissue with known gender dimorphism, especially at the metabolic level. A proteomic comparison of male and female murine biceps brachii was undertaken, resolving an average of 600 protein spots of MW 15-150 kDa and pI 5-8. Twenty-six unique full-length proteins spanning 11 KOG groups demonstrated statistically significant (p< 0.05) abundance differences between genders; the majority of these proteins have metabolic functions. Identified glycolytic enzymes demonstrated decreased abundance in females, while abundance differences in identified oxidative phosphorylation enzymes were specific to the proteins rather than to the functional group as a whole. Certain cytoskeletal and stress proteins showed specific expression differences, and all three phosphorylation states of creatine kinase showed significant decreased abundance in females. Expression differences were significant but many were subtle (≤ 2-fold), and known hormonally-regulated proteins were not identified. We conclude that while gender dimorphism is present in non-exercised murine skeletal muscle, the proteome comparison of male and female biceps brachii in exercise-naive mice indicates subtle differences rather than a large or obviously hormonal dimorphism.

Immunisation With A Multivalent, Subunit Vaccine Reduces Patent Infection In A Natural Bovine Model Of Onchocerciasis During Intense Field Exposure, Benjamin L. Makepeace, Siv Aina Jensen, Sandra J. Laney, Charles K. Nfon, Leo M. Njongmeta, Vincent N. Tanya, Steven A. Williams, Albert E. Bianco, Alexander J. Trees

Biological Sciences: Faculty Publications

Human onchocerciasis, caused by the filarial nematode Onchocerca volvulus, is controlled almost exclusively by the drug ivermectin, which prevents pathology by targeting the microfilariae. However, this reliance on a single control tool has led to interest in vaccination as a potentially complementary strategy. Here, we describe the results of a trial in West Africa to evaluate a multivalent, subunit vaccine for onchocerciasis in the naturally evolved host-parasite relationship of Onchocerca ochengi in cattle. Na ̈ıve calves, reared in fly-proof accommodation, were immunised with eight recombinant antigens of O. ochengi, administered separately with either Freund’s adjuvant or alum. The selected antigens …

Heritable Factors Play A Major Role In Determining Host Responses To Wuchereria Bancrofti Infection In An Isolated South Pacific Island Population, Karen T. Cuenco, Eric A. Ottesen, Steven A. Williams, Thomas B. Nutman, Cathy Steel

Biological Sciences: Faculty Publications

Background. It is increasingly recognized that host genetic factors may play an important role in determining the outcome of filarial infections. To test this hypothesis in bancroftian lymphatic filariasis, pedigree data were collected twice during an 18-year period from an isolated Polynesian population living on a Pacific island where lymphatic filariasis is endemic. Methods. Using variance-component analysis, we examined the contribution of shared genetic and environmental effects on host clinical and immune responses to filarial infection, along with potential confounding determinants. Results. Sex was found to have a negligible influence on heritability estimates, but shared-household effects accounted for up to …

Reducing The Impact Of Pcr-Mediated Recombination In Molecular Evolution And Environmental Studies Using A New-Generation High-Fidelity Dna Polymerase, Daniel J.G. Lahr, Laura A. Katz

Biological Sciences: Faculty Publications

PCR-mediated recombination can greatly impact estimates of diversity, both in environmental studies and in analyses of gene family evolution. Here we measure chimera (PCR-mediated recombinant) formation by analyzing a mixture of eight partial actin sequences isolated from the amoeba Arcella hemisphaerica amplified under a variety of conditions that mimic standard laboratory situations. We further compare a new-generation proofreading processivity-enhanced polymerase to both a standard proofreading enzyme and previously published results. Proofreading polymerases are preferred over other polymerases in instances where evolutionary inferences must be made. Our analyses reveal that reducing the initial template concentration is as critical as reducing the …

Molecular Data Are Transforming Hypotheses On The Origin And Diversification Of Eukaryotes, Yonas I. Tekle, Laura Wegener Parfrey, Laura A. Katz

Biological Sciences: Faculty Publications

The explosion of molecular data has transformed hypotheses on both the origin of eukaryotes and the structure of the eukaryotic tree of life. Early ideas about the evolution of eukaryotes arose through analyses of morphology by light microscopy and, later, electron microscopy. Though such studies have proven powerful at resolving more recent events, theories on origins and diversification of eukaryotic life have been substantially revised in light of analyses of molecular data including gene and, increasingly, whole-genome sequences. By combining these approaches, progress has been made in elucidating the origin and diversification of eukaryotes. Yet many aspects of the evolution …

Genome-Wide Identification Of H-Ns-Controlled, Temperature-Regulated Genes In Escherichiacoli K-12, Christine A. White-Ziegler, Talya R. Davis

Biological Sciences: Faculty Publications

DNA microarrays demonstrate that H-NS controls 69% of the temperature regulated genes in Escherichia coli K-12. H-NS is shown to be a common regulator of multiple iron and other nutrient acquisition systems preferentially expressed at 37°C and of general stress response, biofilm formation, and cold shock genes highly expressed at 23°C.

Tissue Targeted Embryonic Chimeras: Zebrafish Gastrula Cell Transplantation, Elizabeth R. Deschene, Michael J. Barresi

Biological Sciences: Faculty Publications

Certain fundamental questions in the field of developmental biology can only be answered when cells are placed in novel environments or when small groups of cells in a larger context are altered. Watching how one cell interacts with and behaves in a unique environment is essential to characterizing cell functions. Determining how the localized misexpression of a specific protein influences surrounding cells provides insightful information on the roles that protein plays in a variety of developmental processes. Our lab uses the zebrafish model system to uniquely combine genetic approaches with classical transplantation techniques to generate genotypic or phenotypic chimeras. We …

The Impact Of Repeated Rounds Of Mass Drug Administration With Diethylcarbamazine Plus Albendazole On Bancroftian Filariasis In Papua New Guinea, Gary J. Weil, Will Kastens, Melinda Susapu, Sandra J. Laney, Steven A. Williams, Christopher L. King, James W. Kazura, Moses J. Bockarie

Biological Sciences: Faculty Publications

Background: This study employed various monitoring methods to assess the impact of repeated rounds of mass drug administration (MDA) on bancroftian filariasis in Papua New Guinea, which has the largest filariasis problem in the Pacific region.

Methodology/Principal Findings: Residents of rural villages near Madang were studied prior to and one year after each of three rounds of MDA with diethylcarbamazine plus albendazole administered per World Health Organization (WHO) guidelines. The mean MDA compliance rate was 72.9%. Three rounds of MDA decreased microfilaremia rates (Mf, 1 ml night blood by filter) from 18.6% pre-MDA to 1.3% after the third MDA (a …

Living Where The Flow Is Right: How Flow Affects Feeding In Bryozoans, Marney C. Pratt

Biological Sciences: Faculty Publications

Bryozoans are suspension feeding colonial animals that remain attached to the substratum or other surfaces. How well a bryozoan can feed in a particular flow regime could help determine the distribution and abundance of that bryozoan. I tested how velocity of flow affects feeding rate in four species of bryozoans in the laboratory and how these species perform in different flow regimes in the field. I found that one species, Membranipora membranacea, had a higher ingestion rate than did the other three species at all velocities of flow tested. Membranipora also had a higher rate of ingestion at intermediate velocities, …

Determinants Of Success In National Programs To Eliminate Lymphatic Filariasis: A Perspective Identifying Essential Elements And Research Needs, Dominique Kyelem, Gautam Biswas, Moses J. Bockarie, Mark Bradley, Maged El-Setouhy, Peter U. Fischer, Ralph H. Henderson, James W. Kazura, Patrick J. Lammie, Sammy M. Njenga, Eric A. Ottesen, Kapa Ramaiah, Frank O. Richardson, Gary J. Weil, Steven A. Williams

Biological Sciences: Faculty Publications

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in 2000. To understand why some national programs have been more successful than others, a panel of individuals with expertise in LF elimination efforts met to assess available data from programs in 8 countries. The goal was to identify: 1) the factors determining success for national LF elimination programs (defined as the rapid, sustained reduction in microfilaremia/ antigenemia after repeated mass drug administration [MDA]); 2) the priorities for operational research to enhance LF elimination efforts.

Of more than 40 factors identified, the most prominent were 1) initial level of LF …

Patterns Of Body And Tail Length And Body Mass In Sciuridae, Virginia Hayssen

Biological Sciences: Faculty Publications

For squirrels, physical size varies with ancestry, locomotion, and sex. Body length has little variation associated with subfamilies or tribes but varies significantly among genera within tribes. Thus, patterns in body size among genera represent more recent evolutionary pressures. Flying squirrels weigh less than similarly sized tree or ground squirrels but ecological profile and ancestry are confounded for flying squirrels. Tail length has clear relationships with ecological profile in squirrels. Tail length is shorter in ground squirrels, longer in tree squirrels, and longest in flying squirrels. In addition, in arboreal squirrels, females have longer tails, relative to body length, than …

A Reverse Transcriptase-Pcr Assay For Detecting Filarial Infective Larvae In Mosquitoes, Sandra J. Laney, Caitlin J. Buttaro, Sabato Visconti, Nils Pilotte, Reda M.R. Ramzy, Gary J. Weil, Steven A. Williams

Biological Sciences: Faculty Publications

Background: Existing molecular assays for filarial parasite DNA in mosquitoes cannot distinguish between infected mosquitoes that contain any stage of the parasite and infective mosquitoes that harbor third stage larvae (L3) capable of establishing new infections in humans. We now report development of a molecular L3-detection assay for Brugia malayi in vectors based on RT-PCR detection of an L3-activated gene transcript.

Methodology/Principal Findings: Candidate genes identified by bioinformatics analysis of EST datasets across the B. malayilife cycle were initially screened by PCR using cDNA libraries as templates. Stage-specificity was confirmed using RNA isolated from infected mosquitoes. Mosquitoes were collected daily …

Reproduction Within Marmotine Ground Squirrels (Sciuridae, Xerinae, Marmotini): Patterns Among Genera, Virginia Hayssen

Biological Sciences: Faculty Publications

The sciurid tribe Marmotini has a distinctive, highly specialized reproductive profile characterized by annually produced litters of many offspring, each of small mass and fast growth rate. However, not all genera of marmotines follow the reproductive profile of the tribe. In fact, included in the tribe are squirrels with the highest and lowest energetic investment into reproduction of the entire family. Because of its large litter size, Ammospermophilus has the largest energetic investment into reproduction of nearly all squirrels. Also, Ammospermophilus is not limited to 1 litter per year. At the opposite extreme, Marmota has the smallest energetic investment into …

Reproductive Effort In Squirrels: Ecological, Phylogenetic, Allometric, And Latitudinal Patterns, Virginia Hayssen

Biological Sciences: Faculty Publications

The distinctive features of reproduction in squirrels are the lack of allometric influences on the duration of reproductive investment; the strong allometric influences on offspring mass; and a trade-off between number and size of young, suggesting an important developmental component to reproduction. Lengths of gestation and lactation do not vary with body size but neonatal and weaning mass do. Apparently, the major constraint on reproduction in squirrels is not resources per se (food, calories, minerals, or water) but rather the length of time such resources are available. Squirrels adjust growth rate to fit the timing of resource abundance. Within the …