HANNIBAL WOODS: AN EASTERN DECIDUOUS FOREST REMNANT IN HOWARD COUNTY, NEBRASKA

Hannibal Woods is a small, oak-ash (Quercus macrocarpa/ Fraxinus pensylvanica) forest relict located on the south and west sides of Dannebrog, Nebraska. The site was first studied in 1996 as part of a botanical survey of the Loup River Valley. Since the initial work, plant collections have been made several times each growing season through 2005, and an annotated list of plant species has been compiled. This study reports a total of 271 plant species representing 62 families including 86 species that are new records for Howard County. The mature bur oaks at this site average 84.0 cm in diameter. Species that are uncommon in central Nebraska include Agastache nepetoides, Arabis hirsuta var. pycnocarpa, Botrychium virginicum, Bromus ciliatus, Bromus latiglumis, Carex grisea, Carex leavenworthii, Carex molesta, Elymus villosus, and Ulmus rubra. Hannibal Woods is botanically significant in that it supports the growth of plant species which are more representative of sites further east, such as the lower Platte and Missouri River Valleys

A Floristic Survey of Selected Sites in the Loup River Valley, Nance County, Nebraska

The Loup River Valley of Nebraska contains natural, undisturbed wet meadows with significant plant diversity. Even though these sites are infrequent and are often intermixed with heavily grazed pastures or cultivated fields, they support numerous plant and animal species that do not occur elsewhere. We surveyed three study sites (an ungrazed wet meadow; a grazed wet meadow; and a riparian area) that totaled approximately 68.8 ha during the 2010 and 2011 growing seasons. We compiled an annotated vascular plants checklist for the study area that included 244 plant species of which about 49% (119) were new county records. The mean coefficient of conservatism (Cm) values for the ungrazed meadow, the grazed meadow, and the riparian site were 3.54, 3.07, and 3.35 respectively. The floristic quality indices (FQI) were 37.96 for the hay meadow, 28.14 for the grazed meadow, and 31.07 for the riparian site. Jaccard’s Index of Similarity (31.4%) indicated that the grazed and ungrazed meadows had a high degree of community similarity with each containing ~ 80% native species. Our study substantiates the significance of Nance County to the species richness and flora of Nebraska and the Great Plains. Future research and reconnaissance should include the identification and study of additional natural meadows in the lower Loup River Valley

South Loup River Valley Floristics: A Survey of Selected Sites in Buffalo County, Nebraska

Originating in the Nebraska Sand Hills, the South Loup River flows 30 km north of Kearney, Nebraska and traverses the northern edge of Buffalo County as it flows eastward to its confluence with the Middle Loup River in southwestern Howard County. Several diverse plant communities are associated with the South Loup Valley, including wet-meadows, wetland/oxbows, sand prairie, and riparian forest. Over a period of 6 years (2006-2012), we surveyed representative wet meadow, wetland, and sand prairie communities. We compiled an annotated vascular plant checklist that included 324 vascular plant species of which 11 were new county records. Three species of scouring rushes (Equisetophyta) were also listed. Approximately 84.1% (276 species) were native and 15.9% (52) were exotics. The mean coefficient of conservatism (Cm) values for the wet meadow, sand prairie, and wetland sites were 3.51, 3.61, and 4.25 respectively. The floristic quality indices (FQI) were 52.42 for the wet meadow, 32.49 for the sand prairie, and 34.26 for the wetland/oxbow. Several noteworthy sedge species collected in this study were bristly sedge (Carex comosa), shoreline sedge (C. hyalinolepis), ripgut sedge (C. lacustris), and smoothcane sedge (C. laeviconica). Forbs at the west edge of their range included Sullivant’s milkweed (Asclepias sullivantii) and three-seeded mercury (Acalypha rhomboidea). A major objective of our study was to substantiate the significance of the South Loup River Valley to the species richness and flora of Nebraska and the Great Plains

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe

Analysis of shared heritability in common disorders of the brain

ience, this issue p. eaap8757 Structured Abstract INTRODUCTION Brain disorders may exhibit shared symptoms and substantial epidemiological comorbidity, inciting debate about their etiologic overlap. However, detailed study of phenotypes with different ages of onset, severity, and presentation poses a considerable challenge. Recently developed heritability methods allow us to accurately measure correlation of genome-wide common variant risk between two phenotypes from pools of different individuals and assess how connected they, or at least their genetic risks, are on the genomic level. We used genome-wide association data for 265,218 patients and 784,643 control participants, as well as 17 phenotypes from a total of 1,191,588 individuals, to quantify the degree of overlap for genetic risk factors of 25 common brain disorders. RATIONALE Over the past century, the classification of brain disorders has evolved to reflect the medical and scientific communities' assessments of the presumed root causes of clinical phenomena such as behavioral change, loss of motor function, or alterations of consciousness. Directly observable phenomena (such as the presence of emboli, protein tangles, or unusual electrical activity patterns) generally define and separate neurological disorders from psychiatric disorders. Understanding the genetic underpinnings and categorical distinctions for brain disorders and related phenotypes may inform the search for their biological mechanisms. RESULTS Common variant risk for psychiatric disorders was shown to correlate significantly, especially among attention deficit hyperactivity disorder (ADHD), bipolar disorder, major depressive disorder (MDD), and schizophrenia. By contrast, neurological disorders appear more distinct from one another and from the psychiatric disorders, except for migraine, which was significantly correlated to ADHD, MDD, and Tourette syndrome. We demonstrate that, in the general population, the personality trait neuroticism is significantly correlated with almost every psychiatric disorder and migraine. We also identify significant genetic sharing between disorders and early life cognitive measures (e.g., years of education and college attainment) in the general population, demonstrating positive correlation with several psychiatric disorders (e.g., anorexia nervosa and bipolar disorder) and negative correlation with several neurological phenotypes (e.g., Alzheimer's disease and ischemic stroke), even though the latter are considered to result from specific processes that occur later in life. Extensive simulations were also performed to inform how statistical power, diagnostic misclassification, and phenotypic heterogeneity influence genetic correlations. CONCLUSION The high degree of genetic correlation among many of the psychiatric disorders adds further evidence that their current clinical boundaries do not reflect distinct underlying pathogenic processes, at least on the genetic level. This suggests a deeply interconnected nature for psychiatric disorders, in contrast to neurological disorders, and underscores the need to refine psychiatric diagnostics. Genetically informed analyses may provide important "scaffolding" to support such restructuring of psychiatric nosology, which likely requires incorporating many levels of information. By contrast, we find limited evidence for widespread common genetic risk sharing among neurological disorders or across neurological and psychiatric disorders. We show that both psychiatric and neurological disorders have robust correlations with cognitive and personality measures. Further study is needed to evaluate whether overlapping genetic contributions to psychiatric pathology may influence treatment choices. Ultimately, such developments may pave the way toward reduced heterogeneity and improved diagnosis and treatment of psychiatric disorders

A genetic investigation of sex bias in the prevalence of attention-deficit/hyperactivity disorder

Background Attention-deficit/hyperactivity disorder (ADHD) shows substantial heritability and is 2-7 times more common in males than females. We examined two putative genetic mechanisms underlying this sex bias: sex-specific heterogeneity and higher burden of risk in female cases. Methods We analyzed genome-wide autosomal common variants from the Psychiatric Genomics Consortium and iPSYCH Project (20,183 cases, 35,191 controls) and Swedish populationregister data (N=77,905 cases, N=1,874,637 population controls). Results Genetic correlation analyses using two methods suggested near complete sharing of common variant effects across sexes, with rg estimates close to 1. Analyses of population data, however, indicated that females with ADHD may be at especially high risk of certain comorbid developmental conditions (i.e. autism spectrum disorder and congenital malformations), potentially indicating some clinical and etiological heterogeneity. Polygenic risk score (PRS) analysis did not support a higher burden of ADHD common risk variants in female cases (OR=1.02 [0.98-1.06], p=0.28). In contrast, epidemiological sibling analyses revealed that the siblings of females with ADHD are at higher familial risk of ADHD than siblings of affected males (OR=1.14, [95% CI: 1.11-1.18], p=1.5E-15). Conclusions Overall, this study supports a greater familial burden of risk in females with ADHD and some clinical and etiological heterogeneity, based on epidemiological analyses. However, molecular genetic analyses suggest that autosomal common variants largely do not explain the sex bias in ADHD prevalence

A Floristic Study and Species Checklist for the Republican River Valley in Nebraska, with Emphasis on Plants of Concern for Conservation

A botanical survey of the Republican River Valley in Nebraska was initiated during the 1995 growing season and continued through 1998. A major objective of this study was to discover and tabulate rare plants (as designated by the Nebraska Natural Heritage Program), but a general floristic study was also completed. Natural areas, selected because of species composition or location, were identified and described. The study area is characterized by a high degree of human disturbance. Most county floras, with the exception of Webster, are poorly represented. Seven species of conservation concern are reported, which is 1.4% of the total collected flora of 499 species. Dominant vegetation types are riparian forest, tallgrass prairie, mixed-grass prairie, sandsage prairie, and wetlands. Most of the floodplain has been cultivated or grazed and is also subject to fluctuating ground water levels, resulting in a general decline in the diversity of native plant species. The loss of wet meadows throughout the valley has contributed to this lack of diversity

Floristic Analysis of the \u3ci\u3eC. Bertrand and Marian Othmer Schultz Prairie\u3c/i\u3e, A Mixed-Grass Prairie in South-Central Nebraska

The C. Bertrand and Marian Othmer Schultz Prairie is a 259 ha/640 ac/1 mi2 tract of mixed-grass prairie in a region of loess hills in south-central Nebraska. It is on the Kansas border in Webster County, 6.5 km south and 8.1 km east of Red Cloud. A floristic study of the prairie was made during the 1993 and 1994 growing seasons. The 1993 study was accompanied by an ecological survey which determined (1) plant species importance and (2) plant-community relationships using point-step and quadrat methods. Major plant community types are Andropogon scoparius- A. gerardii- Bouteloua gracilis on shallow limy range sites, A. scoparius- Poa pratensis- Bouteloua curtipendula on silty sites, and A. gerardii- A. scoparius- Buchloe dactyloides on lowland overflow sites. The prairie is traversed from south to north by Lost Creek which supports wetland and riparian vegetation. A total of 239 plant species representing 58 families are listed in this report

Woody Plants of the Lower Platte Valley: An Annotated Checklist

A botanical survey of woody plants was made within the Lower Platte Valley in Dodge, Saunders, Douglas, Sarpy, and Cass counties, Nebraska. The following checklist of 50 woody plants is based on the quantitative analysis of 21 sites within the above counties. Species description, habitat type, and frequency of occurrence is given for each species

Extent of Woody Vegetation on the Prairie in Eastern Nebraska, 1855-1857

Early surveyors\u27 notes from five counties bordering the Platte River in eastern Nebraska were utilized to measure the extent of original woody vegetation in this region. These data were compared to field studies from the same area made from 1979-1983, were used to determine areas of prairie-forest transition, and were used to tabulate the extent of woody vegetation in the lower Platte River Valley at the time of European settlement (1855-1857). Using a modified importance value based on relative density and relative dominance of witness trees, the highest ranking pre-settlement tree species were cottonwood [Populus eltoides Marsh. spp. monilifera (Ait.) Eckenw.], bur oak (Quercus macrocarpa Michx.), elms (Ulmus spp.), willows (Salix spp.), and black oak (Quercus velutina Lam.). The original survey indicated the presence of single trees and tree clusters within the original prairie vegetation of eastern Nebraska. Trees are presently more widespread, and their composition differs from the original woody vegetation. Presently, cottonwood, bur oak, American linden (Tilia americana L.), and rough-leaved dogwood (Cornus drummondii Meyer) are more common than they were 130 years ago