The Self and Memory: How Theories of Self Are Crucial in Aiding End-of-Life Decision Making for Dementia Patients

This paper analyzes the source of what we consider to be the self and how such conclusions should inform whether Advance Euthanasia Directives (AEDs) are valid means of exacting end-of-life decisions for patients with dementia. The paper begins with a survey aimed at investigating various popular theories of self and ultimately arrives at John Locke’s memory-based theory of personal identity as the most promising of such arguments. I then address two important critiques of the theory, the branching problem, and the various issues that arise in cases concerning significant memory loss. Ultimately, I analyze the use of Alternative Euthanasia Directives concerning patients suffering from dementia. AEDs have been emerging as a means of ensuring that individuals may die on their own terms considering neurodegenerative diseases such as dementia often result in a loss of mental faculties. AEDs are essentially contracts which state that a given dementia patient should not receive life-saving treatment in the event of illness. However, as we will see, AEDs run the risk of discounting the testimony of patients that are in the throes of dementia who may want such life-saving treatment. Within the argument revolving around AEDs, I analyze topics such as autonomy, personhood, and decision-making, all of which are informed by Locke’s theory. In addition to Locke, I draw from contemporary scholars who have written extensively on this subject. Ultimately, I determine that AEDs have too much potential to harm dementia patients and that in many cases they are not effective in maximizing the well-being of dementia patients. I believe that this conclusion is a step forward in developing an understanding of the self and its ties to dementia. Millions of people are diagnosed with dementia every year which makes answers to these questions more pertinent than ever

Magellan/MMIRS near-infrared multi-object spectroscopy of nebular emission from star forming galaxies at 2<z<3

To investigate the ingredients, which allow star-forming galaxies to present Lyalpha line in emission, we studied the kinematics and gas phase metallicity (Z) of the interstellar medium. We used multi-object NIR spectroscopy with Magellan/MMIRS to study nebular emission from z=2-3 star-forming galaxies discovered in 3 MUSYC fields. We detected emission lines from four active galactic nuclei and 13 high-z star-forming galaxies, including Halpha lines down to a flux of 4.E-17 erg/sec/cm^2. This yielded 7 new redshifts. The most common emission line detected is [OIII]5007, which is sensitive to Z. We were able to measure Z for 2 galaxies and to set upper(lower) limits for another 2(2). The Z values are consistent with 0.3<Z/Zsun<1.2. Comparing the Lyalpha central wavelength with the systemic redshift, we find Delta_v(Lyalpha-[OIII])=70-270 km/sec. High-redshift star-forming galaxies, Lyalpha emitting (LAE) galaxies, and Halpha emitters appear to be located in the low mass, high star-formation rate (SFR) region of the SFR versus stellar mass diagram, confirming that they are experiencing burst episodes of star formation, which are building up their stellar mass. Their Zs are consistent with the relation found for z<2.2 galaxies in the Z versus stellar mass plane. The measured Delta_v(Lyalpha-[OIII]) values imply that outflows of material, driven by star formation, could be present in the z=2-3 LAEs of our sample. Comparing with the literature, we note that galaxies with lower Z than ours are also characterized by similar Delta_v(Lyalpha-[OIII]) velocity offsets. Strong [OIII] is detected in many Lyalpha emitters. Therefore, we propose the Lyalpha/[OIII] flux ratio as a tool for the study of high-z galaxies; while influenced by Z, ionization, and Lyalpha radiative transfer in the ISM, it may be possible to calibrate this ratio to primarily trace one of these effects.Comment: 22 pages, 13 figures, 6 table

Detection of electronic nematicity using scanning tunneling microscopy

Electronic nematic phases have been proposed to occur in various correlated electron systems and were recently claimed to have been detected in scanning tunneling microscopy (STM) conductance maps of the pseudogap states of the cuprate high-temperature superconductor Bi2Sr2CaCu2O8+x (Bi-2212). We investigate the influence of anisotropic STM tip structures on such measurements and establish, with a model calculation, the presence of a tunneling interference effect within an STM junction that induces energy-dependent symmetry-breaking features in the conductance maps. We experimentally confirm this phenomenon on different correlated electron systems, including measurements in the pseudogap state of Bi-2212, showing that the apparent nematic behavior of the imaged crystal lattice is likely not due to nematic order but is related to how a realistic STM tip probes the band structure of a material. We further establish that this interference effect can be used as a sensitive probe of changes in the momentum structure of the sample's quasiparticles as a function of energy.Comment: Accepted for publication (PRB - Rapid Communications). Main text (5 pages, 4 figures) + Supplemental Material (4 pages, 4 figures

A Common Love of Science: The One-Hundredth Meeting of the American Society of Ichthyologists and Herpetologists

One of the most important functions of an academic society such as the American Society of Ichthyologists and Herpetologists (ASIH) is to host conferences for colleagues to directly share and debate ideas and data. Academic society meetings have a long history that grew from social meetings of the privileged in the 16th and 17th centuries during which scientific topics were discussed. Scientific meetings of any nature can provide a stimulating environment to discuss and argue points (Unglow, 2002), as alluded to by Joseph Priestley (1733–1804) in the epigraph, which was written with fond memory of the Lunar Society meetings while he was in political exile (Priestley, 1793). In 1812, a gathering of local scientists formally established The Academy of Natural Sciences of Philadelphia (ANSP), a society “to occupy their leisure, in each other\u27s company, on subjects of natural science” for “the advancement and diffusion of useful, liberal human knowledge.” The founders agreed that the ANSP would be “perpetually exclusive of political, religious and national partialities, antipathies, preventions and prejudices” to avoid potential conflicts with “the interests of science” (Stroud, 1997: 227). With the rise and specialization of academic societies, a concomitant specialization of scientific gatherings followed. Narrowly focused meetings have an important role in advancing the field specific to their topic, but regular (i.e., annual) discipline-wide conferences are important for both the tangible (e.g., presentation of fact) and intangible (e.g., inspiration of new avenues of study) effects they have on the attendees. Conferences also allow attendees the opportunity to conduct Society business through board and committee meetings. In 2021, the ASIH held its 100th in-person meeting, the third and final centennial to be celebrated by this Society (2013 was the 100th year of the Society\u27s journal, Copeia, now Ichthyology & Herpetology, Smith and Mitchell, 2013; 2016 was the 100th year of the ASIH\u27s founding, Hilton and Crump, 2016). This paper celebrates this milestone of the ASIH, and reflects upon the history of the ASIH conferences

A Synaptic Basis for Auditory-Vocal Integration in the Songbird

Songbirds learn to sing by memorizing a tutor song that they then vocally mimic using auditory feedback. This developmental sequence suggests that brain areas that encode auditory memories communicate with brain areas for learned vocal control. In the songbird, the secondary auditory telencephalic region caudal mesopallium (CM) contains neurons that encode aspects of auditory experience. We investigated whether CM is an important source of auditory input to two sensorimotor structures implicated in singing, the telencephalic song nucleus interface (NIf) and HVC. We used reversible inactivation methods to show that activity in CM is necessary for much of the auditory-evoked activity that can be detected in NIf and HVC of anesthetized adult male zebra finches. Furthermore, extracellular and intracellular recordings along with spike-triggered averaging methods indicate that auditory selectivity for the bird’s own song is enhanced between CM and NIf. We used lentiviral-mediated tracing methods to confirm that CM neurons directly innervate NIf. To our surprise, these tracing studies also revealed a direct projection from CM to HVC. We combined irreversible lesions of NIf with reversible inactivation of CM to establish that CM supplies a direct source of auditory drive to HVC. Finally, using chronic recording methods, we found that CM neurons are active in response to song playback and during singing, indicating their potential importance to song perception and processing of auditory feedback. These results establish the functional synaptic linkage between sites of auditory and vocal learning and may identify an important substrate for learned vocal communication

Visualizing Heavy Fermion Confinement and Pauli-Limited Superconductivity in Layered CeCoIn5

Layered material structures play a key role in enhancing electron-electron interactions to create correlated metallic phases that can transform into unconventional superconducting states. The quasi-two-dimensional electronic properties of such compounds are often inferred indirectly through examination of their bulk properties. Here we use scanning tunneling microscopy and spectroscopy to directly probe in cross section the quasi-two-dimensional correlated electronic states of the heavy fermion superconductor CeCoIn5. Our measurements reveal the strong confined nature of heavy quasi-particles, anisotropy of tunneling characteristics, and layer-by-layer modulated behavior of the precursor pseudogap gap phase in this compound. Examining the interlayer coupled superconducting state at low temperatures, we find that the orientation of line defects relative to the d-wave order parameter determines whether in-gap states form due to scattering. Spectroscopic imaging of the anisotropic magnetic vortex cores directly characterizes the short interlayer superconducting coherence length and shows an electronic phase separation near the upper critical in-plane magnetic field, consistent with a Pauli-limited first-order phase transition into a pseudogap phase