Multidimensional Approach to Comparative Avian Visual Systems

Since the birth of visual ecology, comparative studies on how birds see their world have been limited to a small number of species and tended to focus on a single visual trait. This approach has constrained our ability to understand the diversity and evolution of the avian visual system. The goal of this dissertation was to characterize multiple visual dimensions on bird groups that are highly speciouse (e.g., Passeriformes), and test some hypotheses and predictions, using modern comparative tools, on the relationship between different visual traits and their association with visual information sampling behaviors. First, I developed a novel method for characterizing quantitatively the retinal topography (e.g., variation in cell density across the retina) of different bird species in a standardized manner. Second, using this method, I established that retinal configuration has converged particularly in terrestrial vertebrates into three types of retinal specializations: fovea, area, and visual streak, with the highest, intermediate, and lowest peak and peripheral ganglion cell densities, respectively. The implication is that foveate species may have more enhanced visual centers in the brain than non-foveate vertebrates. Third, forest passerines that form multi-species flocks and belong to an insectivore niche differ in their visual system configuration, which appeared associated to behavioral specializations to enhance foraging opportunities: species that searched for food at steep angles had relatively wide binocular fields with a high degree of eye movement right above their short bills, whereas species that searched for food at shallower angles had narrower binocular fields with a high degree of eye movement below their bills. Eye movement allows these species to move their fovea around to visually search for food in the complex forest environment. Fourth, I studied the visual system configuration of nine species of closely related emberizid sparrows, which appear to maximize binocular vision, even seeing their bill tips, to enhance food detection and handling. Additionally, species with more visual coverage had higher visual acuity, which may compensate for their larger blind spots above their foveae, enhancing predator detection. Overall, the visual configuration of these passive prey foragers is substantially different from previously studied avian groups (e.g., sit-and-wait and tactile foragers). Finally, I studied the visual system configuration and visual exploratory behavior of 29 North American bird species across 14 Families. I found that species with a wider blind spot in the visual field (pecten) tended to move their heads at a higher rate probably to compensate for the lack of visual information. Additionally, species with a more pronounced difference in cell density between the fovea and the retinal periphery tended to have a higher degree of eye movement likely to enhance their ability to move their fovea around to gather high quality information. Overall, the avian visual system seems to have specializations to enhance both foraging and anti-predator behaviors that differ greatly between species probably to adjust to specific environmental conditions

Delivering Psychological Services to Military Members

Since 2001, less than half of one percent of the American public have volunteered to serve in the United States Armed Forces. With high-tempo repeated deployments and unconventional warfare, the Post 9/11 military has been exposed to unique trauma and stressors during an unprecedented two-decade long conflict. In voluntarily taking on this role, members are immersed in the total institution of military culture and required to make countless personal sacrifices, often experiencing trauma or other stressors that most in a civilian population will never face. Prevalence rates of mental health problems in active duty as well as veteran populations suggest that approximately 15-30% have acquired mental health conditions (including PTSD, TBI, depression). Substance use and suicidality are often comorbid and may complicate the clinical profile considerably. Current treatment approaches include those well validated and common in general clinical populations (i.e., CBT, PE, CPT) although many have been modified for use with veterans. Nonetheless, despite billions of dollars in public support, many military members continue to not receive the mental health services they need. Challenges include system and access barriers, a lack of military cultural competency in providers, as well as societal and institutional stigma leading to veteran reluctance to seek mental health treatment. Best practice recommendations are offered to clinicians who seek to better serve clients who are military members (both active duty and veterans)

An Innovative Approach to the Mental Health Needs of Humanitarian Mine Action Personnel

In the fields of humanitarian demining and explosive ordnance disposal (EOD), physical traumas related to blast and fragmentation injuries receive a great deal of research attention. In contrast, focus on the psychological health and wellness of humanitarian mine action personnel (HMAP) is lacking. Although research on the incidence of mental health disorders among HMAP is extremely limited, compared with the general population, this group likely suffers more from psychiatric conditions such as posttraumatic stress disorder (PTSD), depression, and anxiety. HMAP work in a high state of hypervigilance because at any given moment in a demining operation, there is risk of death and/or severe maiming. In addition to the inherent risk associated with searching for and working with live unexploded ordnance, deminers are exposed to the constant stress of conflict, which can include shouldering the psychological burden of responsibility for the physical well-being of innocent civilians exposed to explosive devices and witnessing the death and injury of others. Because of the multiple and unique stressors associated with this inherently dangerous work, HMAP likely experience trauma-related mental health conditions at a rate equal to, if not greater than, other high-risk professionals such as military personnel and first-responders (e.g., firefighters, law enforcement, emergency medical technicians). Although estimates vary, rates of PTSD for the latter groups range from 10 percent to over 30 percent depending on the study cited.1,2,3 Therefore, it is critical to identify effective strategies for mitigating the effects of psychological trauma in this high-risk group

Whole genome sequencing for mutation discovery in a single case of lysosomal storage disease (MPS type 1) in the dog.

Mucopolysaccharidosis (MPS) is a metabolic storage disorder caused by the deficiency of any lysosomal enzyme required for the breakdown of glycosaminoglycans. A 15-month-old Boston Terrier presented with clinical signs consistent with lysosomal storage disease including corneal opacities, multifocal central nervous system disease and progressively worsening clinical course. Diagnosis was confirmed at necropsy based on histopathologic evaluation of multiple organs demonstrating accumulation of mucopolysaccharides. Whole genome sequencing was used to uncover a frame-shift insertion affecting the alpha-L-iduronidase (IDUA) gene (c.19_20insCGGCCCCC), a mutation confirmed in another Boston Terrier presented 2 years later with a similar clinical picture. Both dogs were homozygous for the IDUA mutation and shared coat colors not recognized as normal for the breed by the American Kennel Club. In contrast, the mutation was not detected in 120 unrelated Boston Terriers as well as 202 dogs from other breeds. Recent inbreeding to select for recessive and unusual coat colors may have concentrated this relatively rare allele in the breed. The identification of the variant enables ante-mortem diagnosis of similar cases and selective breeding to avoid the spread of this disease in the breed. Boston Terriers carrying this variant represent a promising model for MPS I with neurological abnormalities in humans

Aeroelastic Tailoring of the NASA Common Research Model via Novel Material and Structural Configurations

This work explores the use of tow steered composite laminates, functionally graded metals (FGM), thickness distributions, and curvilinear rib/spar/stringer topologies for aeroelastic tailoring. Parameterized models of the Common Research Model (CRM) wing box have been developed for passive aeroelastic tailoring trade studies. Metrics of interest include the wing weight, the onset of dynamic flutter, and the static aeroelastic stresses. Compared to a baseline structure, the lowest aggregate static wing stresses could be obtained with tow steered skins (47% improvement), and many of these designs could reduce weight as well (up to 14%). For these structures, the trade-off between flutter speed and weight is generally strong, although one case showed both a 100% flutter improvement and a 3.5% weight reduction. Material grading showed no benefit in the skins, but moderate flutter speed improvements (with no weight or stress increase) could be obtained by grading the spars (4.8%) or ribs (3.2%), where the best flutter results were obtained by grading both thickness and material. For the topology work, large weight reductions were obtained by removing an inner spar, and performance was maintained by shifting stringers forward and/or using curvilinear ribs: 5.6% weight reduction, a 13.9% improvement in flutter speed, but a 3.0% increase in stress levels. Flutter resistance was also maintained using straightrotated ribs although the design had a 4.2% lower flutter speed than the curved ribs of similar weight and stress levels were higher. These results will guide the development of a future design optimization scheme established to exploit and combine the individual attributes of these technologies

Forces at Individual Pseudopod-Filament Adhesive Contacts

On-chip cellular force sensors are fabricated from cantilever poly(3,4-ethylene dioxythiophene) filaments that visibly deflect under forces exerted at individual pseudopod-filament adhesive contacts. The shape of the deflected filaments and their ∼3 nN/μm spring constants are predicted by cantilever rod theory. Pulling forces exerted by Dictyostelium discoideumcells at these contacts are observed to reach ∼20 nN without breaking the contact

Doppler ultrasonography of the pectinis oculi artery in harpy eagles (Harpia harpyja)

Twenty harpy eagles (Harpia harpyja) without systemic or ocular diseases were examined to measure blood velocity parameters of the pectinis oculi artery using Doppler ultrasonography. Pectinate artery resistive index (RI) and pulsatility index (PI) were investigated using ocular Doppler ultrasonography. The mean RI and PI values across all eyes were 0.44±0.10 and 0.62±0.20 respectively. Low RI and PI values found in the harpy eagle´s pectinis oculi artery compared with the American pekin ducks one and other tissue suggest indeed a high metabolic activity in pecten oculi and corroborates the hypothesis of a nutritional function and/or intraocular pressure regulation.Keywords: Avian posterior segment, Pulsatility index, Raptors, Resistive index

Genome-wide screening of mouse knockouts reveals novel genes required for normal integumentary and oculocutaneous structure and function.

Oculocutaneous syndromes are often due to mutations in single genes. In some cases, mouse models for these diseases exist in spontaneously occurring mutations, or in mice resulting from forward mutatagenesis screens. Here we present novel genes that may be causative for oculocutaneous disease in humans, discovered as part of a genome-wide screen of knockout-mice in a targeted single-gene deletion project. The International Mouse Phenotyping Consortium (IMPC) database (data release 10.0) was interrogated for all mouse strains with integument abnormalities, which were then cross-referenced individually to identify knockouts with concomitant ocular abnormalities attributed to the same targeted gene deletion. The search yielded 307 knockout strains from unique genes with integument abnormalities, 226 of which have not been previously associated with oculocutaneous conditions. Of the 307 knockout strains with integument abnormalities, 52 were determined to have ocular changes attributed to the targeted deletion, 35 of which represent novel oculocutaneous genes. Some examples of various integument abnormalities are shown, as well as two examples of knockout strains with oculocutaneous phenotypes. Each of the novel genes provided here are potentially relevant to the pathophysiology of human integumentary, or oculocutaneous conditions, such as albinism, phakomatoses, or other multi-system syndromes. The novel genes reported here may implicate molecular pathways relevant to these human diseases and may contribute to the discovery of novel therapeutic targets