Experimental Investigation of Spacecraft Rendezvous and Docking by Development of a 3 Degree of Freedom Satellite Simulator Testbed

This thesis developed a 3 degree of freedom air bearing satellite simulator testbed. The major components of this testbed are a 2-meter by 4-meter granite table, a pair of satellite simulators, and a passive infrared marker array. The goal of this implementation was to achieve soft docking between 2 satellite simulators while relying only on hardware and systems onboard the satellite simulator. The satellite simulators make use of compressed air stored onboard in tanks to supply the air bearing and gas thrusters. The air bearing system provides a thin cushion of air for the satellite simulator to float on, removing surface contact and friction between the satellite simulator and the granite table. This produces a 3 degree of freedom system which is effectively free of the effects of gravity. The infrared marker array is used to provide reference points similar to stars to enable an onboard positioning system using a single observer. The experimental results obtained here demonstrate the successful implementation of this testbed

Association of Variants in the SPTLC1 Gene With Juvenile Amyotrophic Lateral Sclerosis

Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation.Objective: To identify the genetic variants associated with juvenile ALS.Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism.Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members.Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway.Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.</p

Experimental Investigation of Spacecraft Rendezvous and Docking by Development of a 3 Degree of Freedom Satellite Simulator Testbed

This thesis developed a 3 degree of freedom air bearing satellite simulator testbed. The major components of this testbed are a 2-meter by 4-meter granite table, a pair of satellite simulators, and a passive infrared marker array. The goal of this implementation was to achieve soft docking between 2 satellite simulators while relying only on hardware and systems onboard the satellite simulator. The satellite simulators make use of compressed air stored onboard in tanks to supply the air bearing and gas thrusters. The air bearing system provides a thin cushion of air for the satellite simulator to float on, removing surface contact and friction between the satellite simulator and the granite table. This produces a 3 degree of freedom system which is effectively free of the effects of gravity. The infrared marker array is used to provide reference points similar to stars to enable an onboard positioning system using a single observer. The experimental results obtained here demonstrate the successful implementation of this testbed

Multicenter assessment of neoadjuvant chemotherapy for muscle-invasive bladder cancer.

BACKGROUND: The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting. OBJECTIVE: We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort. DESIGN, SETTING, AND PARTICIPANTS: Data were collected retrospectively at 19 centers on patients with clinical cT2-4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013. INTERVENTION: NAC and RC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and ≤pT1N0 stages. RESULTS AND LIMITATIONS: Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n=602; 64.4%), followed by MVAC (n=183; 19.6%) and other regimens (n=144; 15.4%). The rates of pT0N0 and ≤pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p=0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61-1.34]; p=0.6). CONCLUSIONS: Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined. PATIENT SUMMARY: There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer

The prognostic value of the neutrophil-to-lymphocyte ratio in patients with muscle-invasive bladder cancer treated with neoadjuvant chemotherapy and radical cystectomy

The neutrophil-to-lymphocyte ratio (NLR) is an attractive marker because it is derived from routine bloodwork. NLR has shown promise as a prognostic factor in muscle invasive bladder cancer (MIBC) but its value in patients receiving neoadjuvant chemotherapy (NAC) before radical cystectomy (RC) is not yet established. Since NLR is related to an oncogenic environment and poor antitumor host response, we hypothesized that a high NLR would be associated with a poor response to NAC and would remain a poor prognostic indicator in patients receiving NAC

Multicenter assessment of neoadjuvant chemotherapy for muscle-invasive bladder cancer

BACKGROUND: The efficacy of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (BCa) was established primarily with methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), with complete response rates (pT0) as high as 38%. However, because of the comparable efficacy with better tolerability of gemcitabine and cisplatin (GC) in patients with metastatic disease, GC has become the most commonly used regimen in the neoadjuvant setting. OBJECTIVE: We aimed to assess real-world pathologic response rates to NAC with different regimens in a large, multicenter cohort. DESIGN, SETTING, AND PARTICIPANTS: Data were collected retrospectively at 19 centers on patients with clinical cT2-4aN0M0 urothelial carcinoma of the bladder who received at least three cycles of NAC, followed by radical cystectomy (RC), between 2000 and 2013. INTERVENTION: NAC and RC. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was pathologic stage at cystectomy. Univariable and multivariable analyses were used to determine factors predictive of pT0N0 and </=pT1N0 stages. RESULTS AND LIMITATIONS: Data were collected on 935 patients who met inclusion criteria. GC was used in the majority of the patients (n=602; 64.4%), followed by MVAC (n=183; 19.6%) and other regimens (n=144; 15.4%). The rates of pT0N0 and </=pT1N0 pathologic response were 22.7% and 40.8%, respectively. The rate of pT0N0 disease for patients receiving GC was 23.9%, compared with 24.5% for MVAC (p=0.2). There was no difference between MVAC and GC in pT0N0 on multivariable analysis (odds ratio: 0.89 [95% confidence interval, 0.61-1.34]; p=0.6). CONCLUSIONS: Response rates to NAC were lower than those reported in prospective randomized trials, and we did not discern a difference between MVAC and GC. Without any evidence from randomized prospective trials, the best NAC regimen for invasive BCa remains to be determined. PATIENT SUMMARY: There was no apparent difference in the response rates to the two most common presurgical chemotherapy regimens for patients with bladder cancer

Excessive burden of lysosomal storage disorder gene variants in Parkinson's disease

Mutations in the glucocerebrosidase gene (GBA), which cause Gaucher disease, are also potent risk factors for Parkinson's disease. We examined whether a genetic burden of variants in other lysosomal storage disorder genes is more broadly associated with Parkinson's disease susceptibility. The sequence kernel association test was used to interrogate variant burden among 54 lysosomal storage disorder genes, leveraging whole exome sequencing data from 1156 Parkinson's disease cases and 1679 control subjects. We discovered a significant burden of rare, likely damaging lysosomal storage disorder gene variants in association with Parkinson's disease risk. The association signal was robust to the exclusion of GBA, and consistent results were obtained in two independent replication cohorts, including 436 cases and 169 controls with whole exome sequencing and an additional 6713 cases and 5964 controls with exome-wide genotyping. In secondary analyses designed to highlight the specific genes driving the aggregate signal, we confirmed associations at the GBA and SMPD1 loci and newly implicate CTSD, SLC17A5, and ASAH1 as candidate Parkinson's disease susceptibility genes. In our discovery cohort, the majority of Parkinson's disease cases (56%) have at least one putative damaging variant in a lysosomal storage disorder gene, and 21% carry multiple alleles. Our results highlight several promising new susceptibility loci and reinforce the importance of lysosomal mechanisms in Parkinson's disease pathogenesis. We suggest that multiple genetic hits may act in combination to degrade lysosomal function, enhancing Parkinson's disease susceptibility