“How Do You Know Who You Are?”: Marjorie Prime on Envisioning Humanity Through the Faculty of AI-Powered Memory as Reconstructive Tissue

In reference to the theme of the issue devoted to literary extremities, Jordan Harrison’s play Marjorie Prime raises thought-provoking questions about the potential benefits and drawbacks of advanced AI technology by exploring the nature of memory, identity, and mortality, as well as the ethical implications of creating artificial intelligence that can mimic human behavior and emotions. This article argues that the play positions its AI character—a computerized hologram of Marjorie’s late husband Walter—at the intersection of two divergent perspectives on memory reactivation enhanced by AI-powered technology. While, on the one hand, the humanoid is seen as a potent tool which helps to reduce the cognitive impairment caused by dementia, on the other hand, there is a concern that technological interventions may trigger episodic memory change, testifying to the plastic, and thus reconstructive, character of this foundational human faculty. The article seeks to negotiate the interplay of benefits and dangers of technology-assisted memory reactivation by exploring two divergent ideas represented by Marjorie’s daughter Tess and her son-in-law Jon regarding what would comfort their mother, and, ultimately, their differing ways of comforting each other and themselves individually as the carers of an elderly person. In analyzing how creative and destructive forces exhibited by AI-powered digital tools cross-inhabit the declining memory inflicted by dementia, the article unpacks both the vast potential and the limits of technology while attempting to answer uncomfortable questions about the essence of human existence posed by aging and dementia

Superparamagnetic properties of hemozoin

We report that hemozoin nanocrystals demonstrate superparamagnetic properties, with direct measurements of the synthetic hemozoin magnetization. The results show that the magnetic permeability constant varies from mu = 4585 (at -20 degrees C) to 3843 (+20 degrees C), with the values corresponding to a superparamagnetic system. Similar results were obtained from the analysis of the diffusion separation of natural hemozoin nanocrystals in the magnetic field gradient, with mu = 6783 exceeding the value obtained in direct measurements by the factor of 1.8. This difference is interpreted in terms of structural differences between the synthetic and natural hemozoin. The ab initio analysis of the hemozoin elementary cell showed that the Fe3+ ion is in the high-spin state (S = 5/2), while the exchange interaction between Fe3+ electron-spin states was much stronger than k(B)T at room temperature. Thus, the spin dynamics of the neighboring Fe3+ ions are strongly correlated, lending support to the superparamagnetism

Modulation of the oxidative stress in malaria infection by clotrimazole

Antimycotic clotrimazole (CTZ) has demonstrated remarkable activity against Plasmodium falciparum in vitro and in vivo. Hemoglobin degradation by Plasmodium parasites makes amino acids available for protein synthesis, inducing oxidative stress in infected cells and producing free heme. These events represent biochemical targets for potential antimalarials. In this study, we have tested the ability of CTZ to modify the oxidative status in Plasmodium berghei-infected erythrocytes. After hemolysis, activities of superoxide dismutase (SOD), catalase (CAT), glutathione cycle and NADPH+H+-producing dehydrogenases were investigated using UV-visible spectrophotometry. Thiobarbituric acid reactive substances (TBARS) were evaluated as a marker of lipid damage. Results showed that CTZ significantly decreased the overall activity of 6-phosphagluconate dehydrogenase (6PGD) compared to infected and non-treated cells; consequently, the glutathione cycle was inhibited, leaving the parasite vulnerable to the oxidative stress originating from hemoglobin degradation. As a compensatory response, CTZ prevented some loss of SOD and CAT activities in infected cells. The infection triggered lipid peroxidation in erythrocytes, which was decreased by CTZ. These results suggest the presence of a redox unbalance in cells treated with CTZ, discussing a possible effect of this compound disturbing the oxidative status in a Plasmodium berghei-infection.O antifúngico clotrimazol (CTZ) tem demonstrado notável atividade contra Plasmodium falciparum. A degradação da hemoglobina por Plasmodium para a obtenção dos aminoácidos necessários à síntese protéica induz estresse oxidativo em eritrócitos devido à liberação de hemos oxidantes. Estes eventos representam alvos bioquímicos para a produção de antimaláricos potenciais. Neste estudo, testamos a capacidade do CTZ para modificar o estado oxidativo em eritrócitos infectados com Plasmodium berghei. Depois da hemólise, as atividades da superóxido dismutase (SOD), catalase (CAT), desidrogenases produtoras de NADPH+H+ e do ciclo de glutationa (GSH) foram investigados. A produção das espécies reativas ao ácido tiobarbitúrico (TBARS) foi avaliada como marcador de dano lipídico. Os resultados mostraram que o CTZ diminuiu a atividade da 6-fosfogliconato desidrogenase (6PGD), em comparação com eritrócitos infectados e não tratados. Consequentemente, o ciclo da GSH foi inibido, tornando os parasitas vulneráveis ao estresse oxidativo resultante da degradação da hemoglobina. Como resposta compensatória, CTZ impediu a perda de atividade da SOD e CAT nas células infectadas. A infecção induz peroxidação lipídica nos eritrócitos, sendo esta diminuída pelo CTZ. Estes resultados sugerem a existência de desequilíbrio redox nas células tratadas com CTZ, interferindo, assim, com o estado oxidativo verificado durante a infecção malárica

HDP—A Novel Heme Detoxification Protein from the Malaria Parasite

When malaria parasites infect host red blood cells (RBC) and proteolyze hemoglobin, a unique, albeit poorly understood parasite-specific mechanism, detoxifies released heme into hemozoin (Hz). Here, we report the identification and characterization of a novel Plasmodium Heme Detoxification Protein (HDP) that is extremely potent in converting heme into Hz. HDP is functionally conserved across Plasmodium genus and its gene locus could not be disrupted. Once expressed, the parasite utilizes a circuitous “Outbound–Inbound” trafficking route by initially secreting HDP into the cytosol of infected RBC. A subsequent endocytosis of host cytosol (and hemoglobin) delivers HDP to the food vacuole (FV), the site of Hz formation. As Hz formation is critical for survival, involvement of HDP in this process suggests that it could be a malaria drug target

Argumentacja w edukacji: postulaty badań edukacyjnych w polskiej szkole argumentacji

Uwzględniając dotychczasową działalność Polskiej Szkoły Argumentacji, w szczególności jej działalność edukacyjną wyeksponowaną podczas XV konferencji ArgDiaP, sformułowaliśmy postulaty dotyczące dalszej działalności edukacyjnej Szkoły. Ich realizacja w ciągu najbliższych lat mogłaby stanowić grunt dla długoterminowych celów edukacyjnych, takich jak (1) opracowanie spójnego programu nauczania sztuki argumentowania i krytycznego myślenia w szkołach podstawowych i średnich oraz (2) zaprojektowanie ogólnopolskich standardów i ram nauczania przedmiotów powiązanych z argumentacją i krytycznym myśleniem na poziomie studiów uniwersyteckich