Applications of Partial Supersymmetry

I examine quantum mechanical Hamiltonians with partial supersymmetry, and explore two main applications. First, I analyze a theory with a logarithmic spectrum, and show how to use partial supersymmetry to reveal the underlying structure of this theory. This method reveals an intriguing equivalence between two formulations of this theory, one of which is one-dimensional, and the other of which is infinite-dimensional. Second, I demonstrate the use of partial supersymmetry as a tool to obtain the asymptotic energy levels in non-relativistic quantum mechanics in an exceptionally easy way. In the end, I discuss possible extensions of this work, including the possible connections between partial supersymmetry and renormalization group arguments.Comment: 11 pages, harvmac, no figures; typo corrected in identifying info on title pag

A BPS Interpretation of Shape Invariance

We show that shape invariance appears when a quantum mechanical model is invariant under a centrally extended superalgebra endowed with an additional symmetry generator, which we dub the shift operator. The familiar mathematical and physical results of shape invariance then arise from the BPS structure associated with this shift operator. The shift operator also ensures that there is a one-to-one correspondence between the energy levels of such a model and the energies of the BPS-saturating states. These findings thus provide a more comprehensive algebraic setting for understanding shape invariance.Comment: 15 pages, 2 figures, LaTe

Stable periodic waves in coupled Kuramoto-Sivashinsky - Korteweg-de Vries equations

Periodic waves are investigated in a system composed of a Kuramoto-Sivashinsky - Korteweg-de Vries (KS-KdV) equation, which is linearly coupled to an extra linear dissipative equation. The model describes, e.g., a two-layer liquid film flowing down an inclined plane. It has been recently shown that the system supports stable solitary pulses. We demonstrate that a perturbation analysis, based on the balance equation for the field momentum, predicts the existence of stable cnoidal waves (CnWs) in the same system. It is found that the mean value U of the wave field u in the main subsystem, but not the mean value of the extra field, affects the stability of the periodic waves. Three different areas can be distinguished inside the stability region in the parameter plane (L,U), where L is the wave's period. In these areas, stable are, respectively, CnWs with positive velocity, constant solutions, and CnWs with negative velocity. Multistability, i.e., the coexistence of several attractors, including the waves with several maxima per period, appears at large value of L. The analytical predictions are completely confirmed by direct simulations. Stable waves are also found numerically in the limit of vanishing dispersion, when the KS-KdV equation goes over into the KS one.Comment: a latex text file and 16 eps files with figures. Journal of the Physical Society of Japan, in pres

Osteoblastoma of the thyroid cartilage treated with voice preserving laryngeal framework resection

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/99105/1/lary23972.pd

Johnson-Kendall-Roberts theory applied to living cells

Johnson-Kendall-Roberts (JKR) theory is an accurate model for strong adhesion energies of soft slightly deformable material. Little is known about the validity of this theory on complex systems such as living cells. We have addressed this problem using a depletion controlled cell adhesion and measured the force necessary to separate the cells with a micropipette technique. We show that the cytoskeleton can provide the cells with a 3D structure that is sufficiently elastic and has a sufficiently low deformability for JKR theory to be valid. When the cytoskeleton is disrupted, JKR theory is no longer applicable

Is Virtual Cognitive Stimulation Therapy the Future for People with Dementia? An Audit of UK NHS Memory Clinics During the COVID-19 Pandemic

Access to psychosocial interventions for people with dementia, such as Cognitive Stimulation Therapy (CST), has been restricted during the COVID-19 pandemic. Some services have shifted to provision via videoconferencing, but the prevalence of this is unknown. This audit aimed to understand provision of virtual CST (vCST) within National Health Service (NHS) memory clinics throughout the UK and Channel Islands and investigate plans for ongoing CST provision. A cross-sectional survey was circulated to NHS memory clinics, which included closed and open-ended questions to generate quantitative and qualitative data. Thirty-three memory clinics responded to the survey. During the pandemic, 55% of respondents offered vCST, whereas 45% offered no CST. Of those offering vCST, 80% plan to continue with a hybrid model of separate face-to-face and vCST groups, whilst 20% intend to deliver face-to-face CST only. Reported positive aspects of vCST were participant and staff enjoyment, perceived improved digital confidence in participants, and improved accessibility for those who cannot attend face-to-face groups. Negative aspects related to digital poverty, limited digital literacy, support needed from carers, the impact of sensory impairment on engagement, and staff time commitment. Virtual CST has been a feasible alternative to face-to-face services during the pandemic but should not completely replace in-person groups. A hybrid approach would increase accessibility for all. Future research should explore efficacy of vCST and seek to understand patterns of exclusion from such digital interventions

Properties of Ridges in Elastic Membranes

When a thin elastic sheet is confined to a region much smaller than its size the morphology of the resulting crumpled membrane is a network of straight ridges or folds that meet at sharp vertices. A virial theorem predicts the ratio of the total bending and stretching energies of a ridge. Small strains and curvatures persist far away from the ridge. We discuss several kinds of perturbations that distinguish a ridge in a crumpled sheet from an isolated ridge studied earlier (A. E. Lobkovsky, Phys. Rev. E. 53 3750 (1996)). Linear response as well as buckling properties are investigated. We find that quite generally, the energy of a ridge can change by no more than a finite fraction before it buckles.Comment: 13 pages, RevTeX, acknowledgement adde

Decreasing initial telomere length in humans intergenerationally understates age-associated telomere shortening

Telomere length shortens with aging, and short telomeres have been linked to a wide variety of pathologies. Previous studies suggested a discrepancy in age-associated telomere shortening rate estimated by cross-sectional studies versus the rate measured in longitudinal studies, indicating a potential bias in cross-sectional estimates. Intergenerational changes in initial telomere length, such as that predicted by the previously described effect of a father's age at birth of his offspring (FAB), could explain the discrepancy in shortening rate measurements. We evaluated whether changes occur in initial telomere length over multiple generations in three large datasets and identified paternal birth year (PBY) as a variable that reconciles the difference between longitudinal and cross-sectional measurements. We also clarify the association between FAB and offspring telomere length, demonstrating that this effect is substantially larger than reported in the past. These results indicate the presence of a downward secular trend in telomere length at birth over generational time with potential public health implications

Racial and ethnic disparities in pelvic floor disorder awareness

Objectives: Pelvic floor disorders (PFD) affect the quality of life for many women and can be a significant cause of distress. With the United States’ aging population, PFD are becoming increasingly prevalent. Previous population based studies identified both differences in prevalence and baseline knowledge of PFD by race and ethnicity. These prior studies assessing PFD knowledge were limited to single geographical areas or institutions. We aim to conduct a multicenter study across the United States to better understand the baseline knowledge and perceptions of PFD and its variance across different races and ethnicities. Our goal is to provide data that will help deliver culturally competent information to patients. Materials and Methods: This was a multicenter cross-sectional study involving six sites. Upon initial presentation to a urogynecology clinic, patients were evaluated with the Prolapse and Incontinence Knowledge Questionnaire along with additional questions aimed to assess differences in PFD descriptive language, barriers to care, and attitude towards PFD. Surveys were distributed at participating institutions from October 2019 to February 2021. Statistical analyses were performed with Fisher\u27s exact test and Chi-square test, using p \u3c0.05 for statistical significance. Results: A total of 287 women completed the survey, with 27 excluded due to omission of race and or ethnicity responses. Respondents identified their ethnicity as Hispanic (21.8%) and race as White (70.5%), African American (AA) (19.2%), and Other Women of Color (OWOC) (10.3%). Overall, the mean percent correct for the urinary incontinence (UI) and pelvic organ prolapse (POP) sub-scores were 61.2 ± 28.2 and 60.5 ± 28.2, respectively. AA and OWOC had lower scores compared to White respondents in both UI (AA 60.7 ± 30.1; OWOC 46.8 ± 31.2; W 63.5 ± 26.5; p = 0.018) and POP (AA 55.5 ±30.1; OWOC 48.9 ± 31.0; W 64 ± 26.2; p = 0.011). Hispanic women scored lower in both UI (43.9 ± 29.8 vs 66.5 ± 25.3, p \u3c0.001) and POP (46.2 ± 28.4 vs 66.5 ± 25.3, p\u3c0.001) when compared to non-Hispanic respondents. AA and OWOC had decreased knowledge of POP language compared to White respondents (32.3 ± 30.8 % correct vs 35.4 ± 33.6 % correct vs 50.4 ± 32.9 % correct, p \u3c0.001). This was similar for Hispanic compared to non-Hispanic respondents (33.3 ± 31.2 % correct vs 40.1 ± 32.5 % correct, p\u3c0.001). Responses to UI and POP misconception questions were not different by race or ethnicity. Conclusion: This is the first multicenter, cross-sectional survey of a diverse patient population assessing knowledge and perception of PFD. We observed differences between baseline knowledge and language proficiency of PFD amongst AA, White, and OWOC, as well as between Hispanic and non-Hispanic women. This suggests the presence of racial disparities in women pursuing urogynecologic care and highlights the importance of delivering culturally sensitive information to educate women of diverse backgrounds

Investigating the timecourse of accessing conversational implicatures during incremental sentence interpretation

Many contextual inferences in utterance interpretation are explained as following from the nature of conversation and the assumption that participants are rational. Recent psycholinguistic research has focussed on certain of these ‘Gricean’ inferences and have revealed that comprehenders can access them in online interpretation. However there have been mixed results as to the time-course of access. Some results show that Gricean inferences can be accessed very rapidly, as rapidly as any other contextually specified information (Sedivy, 2003; Grodner, Klein, Carbery, & Tanenhaus, 2010); while other studies looking at the same kind of inference suggest that access to Gricean inferences are delayed relative to other aspects of semantic interpretation (Huang & Snedeker, 2009; in press). While previous timecourse research has focussed on Gricean inferences that support the online assignment of reference to definite expressions, the study reported here examines the timecourse of access to scalar implicatures, which enrich the meaning of an utterance beyond the semantic interpretation. Even if access to Gricean inference in support of reference assignment may be rapid, it is still unknown whether genuinely enriching scalar implicatures are delayed. Our results indicate that scalar implicatures are accessed as rapidly as other contextual inferences. The implications of our results are discussed in reference to the architecture of language comprehension