Remotely sensing ecological genomics

Solar radiation is the prime energy source on Earth. It reaches any object in the form of electromagnetic radiation that may be absorbed, transmitted or reflected. The magnitude of these optical processes depends on the optical properties of each object, which in the case of plants relate to their biochemical and structural traits. These plant phenotypic traits result from gene expression underpinned by an individual’s genotype constrained by phylogeny, the environment the individual is exposed to, and the interaction between genotype and the environment. Remote observations of plant phenotypes across space and time may thus hold information about the composition and structure of genetic variation, if a link between spectral and genetic information can be established. This dissertation encompasses studies linking information derived from imaging spectrometer acquisitions under natural conditions with in situ collected information about genetic variation within a tree species, the European beech Fagus sylvatica. It presents the correlation between spectral and genetic information by sequentially expanding temporal, spatial and genetic aspects, and simultaneously accounting for environmental contexts that impact gene expression. By evaluating spectral-genetic similarities across decadal airborne imaging spectrometer acquisitions and accounting for spectral phenotypes and whole-genome sequences of tree individuals from across the species range, the studies provide a proof that observed reflectance spectra hold information about genetic variation within the species. Further, by accounting on uncertainties of spectral measurements and deriving genetic structure of the most abundant tree species in Europe, the dissertation advances the current remote sensing approaches and the knowledge on intraspecific genetic variation. The studies focus particularly on the genetic relatedness between the trees of the test species, whereas the acquired data may allow to establish direct associations between genes and spectral features. The methods used may be expanded to other tree species or applied to spectral data acquired by upcoming spaceborne imaging spectrometers, which overcome current spatiotemporal limitations of data collection, and demonstrate further paths towards the association of genetic variation with variation in spectral phenotypes. The thesis presents the potential of spectral derivation of intraspecific genetic variation within tree species and discusses associated limitations induced by spectral, temporal, spatial and genetic scopes of analysis. This sets a stage towards establishing a means of remote observations of spectral signatures to contribute to monitoring biological variation at the fundamental genetic level, which correlates with ecosystem performance and is an insurance mechanism for populations to adapt to global change

Prediction of Suicidal Behavior Risk among Adolescents Seen in Psychiatric Settings.

Identifying adolescents at elevated risk for suicidal behavior, with the goal of preventing suicidal deaths and the morbidity associated with suicide attempts, is a national priority. However, there are important gaps in the literature concerning which adolescents are most vulnerable to suicidal behavior and how to best identify them. The overarching goal of this dissertation is to improve suicide risk prediction among high-risk adolescents who are most vulnerable to suicidal behavior and repeated suicidal crises and for whom accurate identification of risk is especially critical: psychiatrically hospitalized suicidal adolescents and youth seeking psychiatric emergency services. This dissertation project incorporated three studies examining: (1) the predictive validity and utility of an assessment approach incorporating youths' own assessment of their suicide risk in combination with a clinician-administrated instrument for youth evaluated in a psychiatric emergency department; (2) the impact of post-hospitalization course of suicidal ideation on subsequent suicidal crises, including suicide attempts and psychiatric rehospitalizations, and to identify the baseline predictors of a higher risk course after hospitalization; and (3) a promising theory of suicidal behavior, the Interpersonal-Psychological Theory of Suicidal Behavior, which hypothesizes a proximal pathway to suicidal behavior based on three constructs (low belonging, high perceived burdensomeness, acquired capability for suicide), to determine how well it predicts post-hospitalization suicide attempts within a sample of adolescents who were psychiatrically hospitalized for suicide risk. The results of these studies point to key indicators of risk associated with future suicide attempts and suicide-related crises: low confidence in ability to keep oneself from attempting suicide, persisting suicidal ideation, sense of being a burden on others (for adolescent males and when accompanied by acquired capability for suicide), and sense of thwarted belongingness (particularly for adolescent females and when combined with low acquired capability). The results also point to notable heterogeneity among these youths, synergistic effects of risk factors, and time-varying effects of predictors on suicidal behavior and suicide-risk related crises.PhDPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/113658/1/ewac_1.pd

Rumination, Brooding, and Reflection: Prospective Associations with Suicide Ideation and Suicide Attempts

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151274/1/sltb12507_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151274/2/sltb12507.pd

Identifying Adolescents at Highly Elevated Risk for Suicidal Behavior in the Emergency Department

Objective: The feasibility and concurrent validity of adolescent suicide risk screening in medical emergency departments (EDs) has been documented. The objectives of this short-term prospective study of adolescents who screened positive for suicide risk in the ED were: 1) to examine adolescents' rate of suicidal behavior during the 2 months following their ED visits and compare it with reported rates for psychiatric samples; and 2) to identify possible predictors of acute risk for suicidal behavior in this at-risk sample. Method: Participants were 81 adolescents, ages 14?19 years, seeking services for psychiatric and nonpsychiatric chief complaints, who screened positive for suicide risk because of recent suicidal ideation, a suicide attempt, and/or depression plus alcohol or substance misuse. A comprehensive assessment of suicidal behavior, using the Columbia-Suicide Severity Rating Scale, was conducted at baseline and 2 month follow-up. Results: Six adolescents (7.4%) reported a suicide attempt and 15 (18.5%) engaged in some type of suicidal behavior (actual, aborted, or interrupted suicide attempt; preparatory behavior) during the 2 months following their ED visit. These rates suggest that this screen identified a high-risk sample. Furthermore, adolescents who screened positive for suicidal ideation and/or attempt plus depression and alcohol/substance misuse were most likely to engage in future suicidal behavior (38.9%). Conclusions: In this study, use of a higher screen threshold (multiple suicide risk factors) showed promise for identifying highly elevated acute risk for suicidal behavior.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140322/1/cap.2014.0049.pd

Positive and Negative Expectations of Hopelessness as Longitudinal Predictors of Depression, Suicidal Ideation, and Suicidal Behavior in High‐Risk Adolescents

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136513/1/sltb12273.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136513/2/sltb12273_am.pd

Flow cytometric analysis of CD55 and CD59 expression on blood cells in paroxysmal nocturnal haemoglobinuria

PNH is a rare clonal disorder of hematopoietic stem cells, therefore all blood cells lineages are involved. The main feature is an increased sensitivity of erythrocytes to complement-mediated cell lysis due to deficiency of membrane-bound GPI (glycosylphosphatidylinositol)-anchored proteins which normally function as inhibitors of reactive hemolysis. In the present study, we performed flow cytometric analysis using monoclonal antibodies against CD55 and CD59 for the detection of PNH-type clone in the blood of 50 patients (28 females and 22 males, age range 7-67 yrs). In one patient only we found a large population (95%) of granulocytes with decreased expression of both CD55 and CD59 molecules (type I PNH) and in two others with partial loss of CD55 expression (type II PNH). The expression was determined chiefly on granulocytes which in the control group showed reliable and high expression of CD55 and CD59

Self‐Efficacy to Avoid Suicidal Action: Factor Structure and Convergent Validity among Adults in Substance Use Disorder Treatment

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109886/1/sltb12101.pd

Genetic constraints on temporal variation of airborne reflectance spectra and their uncertainties over a temperate forest

Remote sensing enhances large-scale biodiversity monitoring by overcoming temporal and spatial limitations of ground-based measurements and allows assessment of multiple plant traits simultaneously. The total set of traits and their variation over time is specific for each individual and can reveal information about the genetic composition of forest communities. Measuring trait variation among individuals of one species continuously across space and time is a key component in monitoring genetic diversity but difficult to achieve with ground-based methods. Remote sensing approaches using imaging spectroscopy can provide high spectral, spatial, and temporal coverage to advance the monitoring of genetic diversity, if sufficient relation between spectral and genetic information can be established. We assessed reflectance spectra from individual Fagus sylvatica L. (European beech) trees acquired across eleven years from 69 flights of the Airborne Prism Experiment (APEX) above the same temperate forest in Switzerland. We derived reflectance spectra of 68 canopy trees and correlated differences in these spectra with genetic differences derived from microsatellite markers among the 68 individuals. We calculated these correlations for different points in time, wavelength regions and relative differences between wavelength regions. High correlations indicate high spectral-genetic similarities. We then tested the influence of environmental variables obtained at temporal scales from days to years on spectral-genetic similarities. We performed an uncertainty propagation of radiance measurements to provide a quality indicator for these correlations. We observed that genetically similar individuals had more similar reflectance spectra, but this varied between wavelength regions and across environmental variables. The short-wave infrared regions of the spectrum, influenced by water absorption, seemed to provide information on the population genetic structure at high temperatures, whereas the visible part of the spectrum, and the near-infrared region affected by scattering properties of tree canopies, showed more consistent patterns with genetic structure across longer time scales. Correlations of genetic similarity with reflectance spectra similarity were easier to detect when investigating relative differences between spectral bands (maximum correlation: 0.40) than reflectance data (maximum correlation: 0.33). Incorporating uncertainties of spectral measurements yielded improvements of spectral-genetic similarities of 36% and 20% for analyses based on single spectral bands, and relative differences between spectral bands, respectively. This study highlights the potential of dense multi-temporal airborne imaging spectroscopy data to detect the genetic structure of forest communities. We suggest that the observed temporal trajectories of reflectance spectra indicate physiological and possibly genetic constraints on plant responses to environmental change