Topological nature of non-Hermitian degenerate bands in structural parameter space

In photonics, band degeneracies at high-symmetry points in wavevector space have been shown to exhibit rich physical phenomena. However, obtaining degenerate bands away from such points is highly nontrivial. In this work, we achieve complex band degeneracy in a photonic crystal structure over a region of momentum space. We show that this band degeneracy corresponds to polarization-independent transmission, which can be harnessed for nonlocal metasurface design. Moreover, we find that the band degeneracy manifests as a topological singularity in the structural parameter space of the system. Our work highlights the importance of topological concepts in the design of polarization-independent photonic structures.Comment: 11 pages, 4 figure

The Effectiveness of JeffWLP for Weight Loss and General Nutritional Knowledge in Obese Patients

PURPOSE: The increasing prevalence of obesity urgently requires effective management strategies. This study evaluates the effectiveness of Jefferson Weight Loss Program (JeffWLP), a trained medical student-delivered health education program in a predominantly African-American patient cohort. METHODS: A randomized controlled trial was performed enrolling 30 patients with an average socioeconomic status of 5.8 (10 maximum). The intervention group (n=18) completed JeffWLP, a low-cost, 12-week health coaching program combining education sessions with graded step exercises. The control group (n=12) received usual care. Mean baseline age, BMI, and General Nutritional Knowledge Questionnaire (GNKQ) scores were: 46±13 years, 38±5, and 14.7±1.9 (maximum score=17) respectively. RESULTS: Patients completing JeffWLP achieved greater weight loss, with mean weight loss of 6.1±7.8 pounds (p=0.01) compared to 4.4±7.5 pounds weight gain in controls (p=0.14). This corresponded to 2.7±3.3% weight reduction (p=0.01) and 2.0±3.5% weight gain (p=0.15). Mean endpoint GNKQ scores decreased overall slightly to 14.5±1.9, but improvement correlated with total, group, and 1:1 class attendance (R=0.81, 0.75, 0.77, p=0.0004, 0.002, 0.001 respectively). CONCLUSIONS: The significant weight reduction of 2.7±3.3% achieved in just 12 weeks of JeffWLP suggests meaningful progress towards improving cardiovascular health. Correlation of GNKQ scores to attendance suggests that patients acquired knowledge facilitating these positive outcomes. Our results support the establishment of student-delivered patient education programs to help combat the obesity epidemic.https://jdc.jefferson.edu/aoa_research_symposium_posters/1010/thumbnail.jp

Effects of continuous positive airway pressure (CPAP) sleep apnea treatment on mild cognitive impairment (MCI) and cardiovascular risk

There is a documented association between sleep apnea and earlier onset of cognitive impairment later in life. We hypothesize that nightly treatment with CPAP therapy will improve MCI status as estimated by a panel of neuropsychiatry tests in patients \u3e55 with OSA and concomitant memory complaints. With a prospective cohort design, patients compliant with CPAP therapy are being compared to noncompliant patients and a non-OSA control group. My role in this multi-site project was to screen potential patients from Jefferson’s sleep clinic for eligibility for study enrollment. This study is still ongoing. OSA’s high prevalence makes it a worthwhile endeavor to find successful treatment for the prevention of progression of MCI to Alzheimer’s disease in OSA patients. I am also playing a key role in a related project examining the effect of CPAP compliance on cardiovascular risk and cardiovascular risk factors in OSA patients. My role is to compile each patient’s monthly CPAP compliance data in order to compare cardiovascular risk factors to measures of effective CPAP use. I am personally focusing on heart rate as a measure of sympathetic nervous system activation. We are in the pilot phase of data collection for this project. For the first sample of 10 patients, greater CPAP compliance was associated with a lower heart rate (insert data). Those that used CPAP greater than x hours a night had the lowest heart rate (insert data). These findings display the pivotal role CPAP therapy can have on improving cardiovascular risk factors in those with OSA

Bone and Cartilage Degeneration in Mice Following Long-Duration Spaceflight: The Role of Bone Marrow Stem Cells

The detrimental effects of mechanical unloading in microgravity, including the musculo-skeletal system, are well documented. However, the effects of mechanical unloading on joint health and the interaction between bone and cartilage specifically, are less well known. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. Furthermore, we have identified the cell cycle arrest molecule, CDKN1ap21, as specifically up-regulated during spaceflight exposure and localized to osteoprecursors on the bone surface and chondroprogenitors in articular cartilage that are both required for normal tissue regeneration. The 30-day BionM1 and 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight resulting in significant tissue alterations and we specifically studied the hip joint (pelvis and proximal femur) to elucidate these effects. To test this hypothesis we analyzed bone and bone marrow stem cells using techniques including high-resolution Microcomputed Tomography (MicroCT), in-vivo differentiation and migration assays, and whole transcriptome expression profiling. We found that exposure to spaceflight for 30 days results in a significant decrease in bone volume fraction (-31), trabecular thickness (-14) and trabecular number (-20). Similar decrements in bone volume fraction (-27), trabecular number (-13) and trabecular thickness (-17) were found in female mice exposed to 37 days spaceflight. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. Microarray analysis also revealed that the top pathways altered during spaceflight include activation of matrix metalloproteinases, oxidative stress signaling and inflammation in both whole bone tissue and isolated bone marrow stem cells. In conclusion, the observed inhibition of stem cell-based tissue regeneration persists during long-duration spaceflight. Furthermore, spaceflight mice exhibit disruption of the epiphyseal boundary and endochondral ossification of the femoral head, and an inhibition of stem cell based tissue regeneration, which, taken together, may indicate onset of an accelerated aging phenotype with signs of osteoarthritic disease

The Role of CDKN1a/p21 in Cellular Senescence of Bone Marrow Stem Cells Under Spaceflight Stressors

Spaceflight environments and their associated conditions, such as microgravity and space radiation, cause many biological functions formerly considered to be standard to behave in nonstandard ways. Exposure to microgravity has shown to induce deleterious effects in stem cell-based tissue regeneration, leading to immune system and healing response impairments as well as muscle and bone density loss. Such risks must be mitigated in order for long-term human space exploration to proceed. Thus, our work seeks to explore mechanisms of stem cell-based tissue regeneration that experience changes in spaceflight environments. Cellular senescence is a process of inducing cell cycle arrest that can be initiated by various stimuli. This function is influenced by two major pathways, controlled by p53 and pRB tumor suppressor proteins. p53 activity targets the cyclin-dependent kinase inhibitor gene p21Cdkn1a in osteogenic cell cycle arrest. Under conditions of mechanical unloading, stem cell-based tissue regeneration has shown to be decreased in both proliferation and differentiation, as many cells are arrested in progenitor states. p21 has shown upregulation in expression under conditions of microgravity, suggesting its role in regenerative bone formation arrest in space. p21 levels are found to be elevated independent of p53, suggesting a decrease in proliferation and regeneration without apoptosis, but rather through cell cycle arrest alone. Thus, we hypothesize that p21 is a mediator of cellular senescence in bone marrow stem cells. Culturing of bone marrow stem cells from wild type and p21 knockout mice under osteoblastogenic conditions will be completed to explore the role of p21Cdkn1a in stem cell proliferation and maturation. We believe that decreases in somatic stem cell differentiation may occur after spaceflight due to signal pathway alterations that result in downstream inhibition of genes involved in differentiation, preventing tissue from repairing and regenerating normally

Reducing cognitive arousal and sleep effort alleviates insomnia and depression in pregnant women with DSM-5 insomnia disorder treated with a mindfulness sleep program

OBJECTIVES: Combining mindfulness with behavioral sleep strategies has been found to alleviate symptoms of insomnia and depression during pregnancy, but mechanisms for this treatment approach remain unclear. The present study examined nocturnal cognitive arousal and sleep effort as potential treatment mechanisms for alleviating insomnia and depression via a mindfulness sleep program for pregnant women. METHODS: Secondary analysis from a proof-of-concept trial of 12 pregnant women with DSM-5 insomnia disorder who were treated with Perinatal Understanding of Mindful Awareness for Sleep (PUMAS), which places behavioral sleep strategies within a mindfulness framework. Data were collected across eight weekly assessments: pretreatment, six sessions, and posttreatment. Measures included the insomnia severity index (ISI), Edinburgh postnatal depression scale (EPDS), pre-sleep arousal scale\u27s cognitive factor (PSASC), and the Glasgow sleep effort scale (GSES). We used linear mixed modeling to test cognitive arousal and sleep effort as concurrent and prospective predictors of insomnia and depression. RESULTS: Most patients reported high cognitive arousal before PUMAS (75.0%), which decreased to 8.3% after treatment. All insomnia remitters reported low cognitive arousal after treatment, whereas half of nonremitters continued reporting high cognitive arousal. Both nocturnal cognitive arousal and sleep effort were associated with same-week changes in insomnia throughout treatment, and sleep effort yielded a prospective effect on insomnia. Lower levels of nocturnal cognitive arousal and sleep effort prospectively predicted reductions in depression. CONCLUSIONS: The present study offers preliminary evidence that reducing sleep effort and nocturnal cognitive arousal may serve as key mechanisms for alleviating insomnia and depression via mindfulness-based insomnia therapy. ClinicalTrials.gov ID: NCT04443959

Continuous positive airway pressure therapy effects on lipid and hepatic function test values

Introduction : Continuous positive airway pressure (CPAP) therapy is an established therapy for patients diagnosed with obstructive sleep apnea (OSA). The following study aims to measure the impact of CPAP therapy on lipid and liver profiles of patients diagnosed with OSA. We hypothesize that CPAP therapy will improve patient serum lipid and liver measures in this patient population compared to patient baseline prior to CPAP therapy. Furthermore, we also will examine differences in hepatic ultrasound results for OSA patients on CPAP therapy. Methods: The target patient population has moderate-severe OSA, defined as an Apnea-Hypopnea Index greater than 15. The intervention is defined as a minimum of four hours of CPAP therapy use nightly on average. For lipid panel outcomes, we recorded high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), total cholesterol (TC), and triglycerides (TG). For liver panel outcomes, we measured aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values. All values were compared to each patients’ averaged baseline values six months prior to initiation of CPAP therapy. Furthermore, we also examined hepatic ultrasound results prior to and after beginning CPAP therapy. Results: Data collection is currently ongoing. We expect preliminary data of ten chart reviews of eligible subjects show lower HDL, LDL, TC, TG, AST, and ALT on lipid and liver function tests after consistent CPAP use compared to baseline. Unfortunately, due to this initial small pilot sample size, no significant findings with regard to hepatic ultrasound results have been observed. Discussion: Our results demonstrate that consistent CPAP therapy use helps to lower liver function and lipid tests. This provides support that CPAP therapy, in conjunction with treating OSA, may help to improve outcome values for patients with hypertriglyceridemia and poor liver function. We will continue to collect data on a much larger sample of patients to adequately test our study hypothesis regarding the effects of CPAP therapy effects on hepatic outcomes, such as liver failure, which would provide further support of the beneficial effects of CPAP therapy on vulnerable populations