STI-2062-1

This project investigated solar variability, power conversion and electric power grid response aspects of high penetration solar PV. These are the primary determining factors for acceptable penetration levels. Therefore, the study not only focused on the power system interactions, but also on the design of advanced power conditioners to explore more efficient design options and to look into advanced control impacts to the higher penetration PV deployment systems. Through extensive laboratory and field testing, the team gathered the essential information to better understand grid characteristics, PV systems configuration and power conditioning systems

Collaboration gets the most out of software

By centralizing many of the tasks associated with the upkeep of scientific software, SBGrid allows researchers to spend more of their time on research

Kestrel Aeronautics: KA-Ranger

As combat environments continue to evolve, there is a growing need for dedicated aircraft to provide close air support to ground forces. In response to the 2021 AIAA Undergraduate Team Aircraft Design Competition RFP, Kestrel Aeronautics developed the KA-Ranger, an affordable, light attack aircraft to operate from austere fields and replace current helicopters in close air support missions. The design must accomplish an attack mission with full weapons payload, cruise for 200 nmi at an altitude ≥10,000 ft, and loiter 4 hours. It must also complete a long-range ferry mission of at least 900 nmi range at 60% payload, cruising at an altitude ≥18,000 ft. Both missions require reserves for an additional 3,000 ft climb and 45 minute loiter. A survey of current attack aircraft yielded the initial design including a turboprop engine, low mounted rectangular wings, conventional tail, and retractable tricycle landing gear. The aircraft weighs approximately 12,000 lbf with two crew members, an integrated gun, and 3,000 lbf of externally mounted armament. Current design activities include material selection, detailed structural design, weapon and fuel placement with stability analysis, drag assessment, and power analysis to confirm the KA Ranger’s flight performance

Toward an Extended Definition of Major Depressive Disorder Symptomatology: Digital Assessment and Cross-validation Study.

BACKGROUND: Diagnosing major depressive disorder (MDD) is challenging, with diagnostic manuals failing to capture the wide range of clinical symptoms that are endorsed by individuals with this condition. OBJECTIVE: This study aims to provide evidence for an extended definition of MDD symptomatology. METHODS: Symptom data were collected via a digital assessment developed for a delta study. Random forest classification with nested cross-validation was used to distinguish between individuals with MDD and those with subthreshold symptomatology of the disorder using disorder-specific symptoms and transdiagnostic symptoms. The diagnostic performance of the Patient Health Questionnaire-9 was also examined. RESULTS: A depression-specific model demonstrated good predictive performance when distinguishing between individuals with MDD (n=64) and those with subthreshold depression (n=140) (area under the receiver operating characteristic curve=0.89; sensitivity=82.4%; specificity=81.3%; accuracy=81.6%). The inclusion of transdiagnostic symptoms of psychopathology, including symptoms of depression, generalized anxiety disorder, insomnia, emotional instability, and panic disorder, significantly improved the model performance (area under the receiver operating characteristic curve=0.95; sensitivity=86.5%; specificity=90.8%; accuracy=89.5%). The Patient Health Questionnaire-9 was excellent at identifying MDD but overdiagnosed the condition (sensitivity=92.2%; specificity=54.3%; accuracy=66.2%). CONCLUSIONS: Our findings are in line with the notion that current diagnostic practices may present an overly narrow conception of mental health. Furthermore, our study provides proof-of-concept support for the clinical utility of a digital assessment to inform clinical decision-making in the evaluation of MDD

The Delta Study - Prevalence and characteristics of mood disorders in 924 individuals with low mood: Results of the of the World Health Organization Composite International Diagnostic Interview (CIDI).

OBJECTIVES: The Delta Study was undertaken to improve the diagnosis of mood disorders in individuals presenting with low mood. The current study aimed to estimate the prevalence and explore the characteristics of mood disorders in participants of the Delta Study, and discuss their implications for clinical practice. METHODS: Individuals with low mood (Patients Health Questionnaire-9 score ≥5) and either no previous mood disorder diagnosis (baseline low mood group, n = 429), a recent (≤5 years) clinical diagnosis of MDD (baseline MDD group, n = 441) or a previous clinical diagnosis of BD (established BD group, n = 54), were recruited online. Self-reported demographic and clinical data were collected through an extensive online mental health questionnaire and mood disorder diagnoses were determined with the World Health Organization Composite International Diagnostic Interview (CIDI). RESULTS: The prevalence of BD and MDD in the baseline low mood group was 24% and 36%, respectively. The prevalence of BD among individuals with a recent diagnosis of MDD was 31%. Participants with BD in both baseline low mood and baseline MDD groups were characterized by a younger age at onset of the first low mood episode, more severe depressive symptoms and lower wellbeing, relative to the MDD or low mood groups. Approximately half the individuals with BD diagnosed as MDD (49%) had experienced (hypo)manic symptoms prior to being diagnosed with MDD. CONCLUSIONS: The current results confirm high under- and misdiagnosis rates of mood disorders in individuals presenting with low mood, potentially leading to worsening of symptoms and decreased well-being, and indicate the need for improved mental health triage in primary care

Circulating Levels of Tissue Factor Microparticle Procoagulant Activity Are Reduced With Antiretroviral Therapy and Are Associated With Persistent Inflammation and Coagulation Activation Among HIV-Positive Patients

Activation of coagulation pathways may contribute to risk for non-AIDS related conditions among HIV positive patients. We measured tissue factor-dependent procoagulant activity on circulating microparticles (MP-TF) in the plasma of 163 HIV positive participants, both untreated and treated, with viral suppression. MP-TF activity was 39% lower among treated versus untreated participants (p<0.001), which persisted in adjusted models (−36%; p=0.03). Among treated participants, MP-TF activity correlated modestly with D-dimer (r=0.24; p=0.01), vWF (r=0.36; p<0.001), and IL-6 (r=0.20; p=0.04) levels. Future research should focus on mechanisms driving residual functional TF activity and whether these alterations have clinical consequences for non-AIDS defining complications

Research Report No. 29, Site Index Equations for Loblolly and Slash Pine Plantations in East Texas, Update: 1994

In 1986, equations to estimate site index in loblolly and slash pine plantations in East Texas were published (Lenhart et al. 1986). Subsequently, updated site index prediction equations were published in 1993 (Vaughn et al. 1993). Both sets of equations were developed using data collected from East Texas Pine Plantation Research Project (ETPPRP) permanent plots distributed throughout East Texas. The site index prediction equations were designed to estimate tree height 25 years from planting, ie., index age = 25 years. Data for the 1986 and 1993 site index prediction equations were from measurements of the ETPPRP permanent plots during 19182-1984 (a 3-year period) and 1982-1992 (an 11-year period), respectively. In this 1994 update, new versions of site index prediction equations are presented for loblolly and slash pine plantations in East Texas based on information from repeated measurements of the ETPPRP permanent plots during 1982-1 993. During this 12-year period, the ETPPRP plots have been measured four times. As a result, the new loblolly pine site Index equation is based on the analysis of 653 ageheight pairs, and the new slash pine site index prediction equation is derived from 296 age-height pairs. The equations in this 1994 update should quantify the productivity of East Texas loblolly and slash pine plantations in a more accurate and reliable manner than the two previous sets of equations

Genetic Mapping of Multiple Metabolic Traits Identifies Novel Genes for Adiposity, Lipids and Insulin Secretory Capacity in Outbred Rats

Despite the successes of human genome-wide association studies, the causal genes underlying most metabolic traits remain unclear. We used outbred heterogeneous stock (HS) rats, coupled with expression data and mediation analysis, to identify quantitative trait loci (QTLs) and candidate gene mediators for adiposity, glucose tolerance, serum lipids, and other metabolic traits. Physiological traits were measured in 1519 male HS rats, with liver and adipose transcriptomes measured in over 410 rats. Genotypes were imputed from low coverage whole genome sequence. Linear mixed models were used to detect physiological and expression QTLs (pQTLs and eQTLs, respectively), employing both SNP- and haplotype-based models for pQTL mapping. Genes with cis-eQTLs that overlapped pQTLs were assessed as causal candidates through mediation analysis. We identified 14 SNP-based pQTLs and 19 haplotype-based pQTLs, of which 10 were in common. Using mediation, we identified the following genes as candidate mediators of pQTLs: Grk5 for a fat pad weight pQTL on Chr1, Krtcap3 for fat pad weight and serum lipids pQTLs on Chr6, Ilrun for a fat pad weight pQTL on Chr20 and Rfx6 for a whole pancreatic insulin content pQTL on Chr20. Furthermore, we verified Grk5 and Ktrcap3 using gene knock-down/out models, thereby shedding light on novel regulators of obesity