Ocular surface temperature in age-related macular degeneration

Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD) eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The ocular surface temperature (OST) of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA) test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272). OST in AMD patients was significantly lower than in controls (P>0.05). Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD

Physics-inspired Ising Computing with Ring Oscillator Activated p-bits

The nearing end of Moore's Law has been driving the development of domain-specific hardware tailored to solve a special set of problems. Along these lines, probabilistic computing with inherently stochastic building blocks (p-bits) have shown significant promise, particularly in the context of hard optimization and statistical sampling problems. p-bits have been proposed and demonstrated in different hardware substrates ranging from small-scale stochastic magnetic tunnel junctions (sMTJs) in asynchronous architectures to large-scale CMOS in synchronous architectures. Here, we design and implement a truly asynchronous and medium-scale p-computer (with $\approx$ 800 p-bits) that closely emulates the asynchronous dynamics of sMTJs in Field Programmable Gate Arrays (FPGAs). Using hard instances of the planted Ising glass problem on the Chimera lattice, we evaluate the performance of the asynchronous architecture against an ideal, synchronous design that performs parallelized (chromatic) exact Gibbs sampling. We find that despite the lack of any careful synchronization, the asynchronous design achieves parallelism with comparable algorithmic scaling in the ideal, carefully tuned and parallelized synchronous design. Our results highlight the promise of massively scaled p-computers with millions of free-running p-bits made out of nanoscale building blocks such as stochastic magnetic tunnel junctions.Comment: To appear in the 22nd IEEE International Conference on Nanotechnology (IEEE-NANO 2022

A magneto-mechanical accelerometer based on magnetic tunnel junctions

Accelerometers have widespread applications and are an essential component in many areas such as automotive, consumer electronics and industrial applications. Most commercial accelerometers are based on micro-electromechanical system (MEMS) that are limited in downscaling and power consumption. Spintronics-based accelerometers have been proposed as alternatives, however, current proposals suffer from design limitations that result in reliability issues and high cost. Here we propose spintronic accelerometers with magnetic tunnel junctions (MTJs) as building block, which map accelerations into a measurable voltage across the MTJ terminals. The device exploits elastic and dipolar coupling as a sensing mechanism and the spintronic diode effect for the direct read out of the acceleration. The proposed technology represents a potentially competitive and scalable solution to current capacitive MEMS-based approaches that could lead to a step forward in many of the commercial applications.Comment: main document with 4 figures + supplemental informatio

Evaluating spintronics-compatible implementations of Ising machines

The commercial and industrial demand for the solution of hard combinatorial optimization problems push forward the development of efficient solvers. One of them is the Ising machine which can solve combinatorial problems mapped to Ising Hamiltonians. In particular, spintronic hardware implementations of Ising machines can be very efficient in terms of area and performance, and are relatively low-cost considering the potential to create hybrid CMOS-spintronic technology. Here, we perform a comparison of coherent and probabilistic paradigms of Ising machines on several hard Max-Cut instances, analyzing their scalability and performance at software level. We show that probabilistic Ising machines outperform coherent Ising machines in terms of the number of iterations required to achieve the problem s solution. Nevertheless, high frequency spintronic oscillators with sub-nanosecond synchronization times could be very promising as ultrafast Ising machines. In addition, considering that a coherent Ising machine acts better for Max-Cut problems because of the absence of the linear term in the Ising Hamiltonian, we introduce a procedure to encode Max-3SAT to Max-Cut. We foresee potential synergic interplays between the two paradigms.Comment: 26 pages, 6 Figures, submitted for publication in Phys. Rev. Applied (it will be presented at intermag 2023 in Japan

The Genetic Landscape of Serbian Populations through Mitochondrial DNA Sequencing and Non-Recombining Region of the Y Chromosome Microsatellites

The Balkan Peninsula is known to represent a complex cultural mosaic and it is a strategic area because it represents a gateway into Europe from the Near East. This research seeks to evaluate the variability of both uniparental markers (mtDNA and non-recombining region of the Y chromosome) to dissect the genetic makeup of Serbians. The whole sample pertains to 257 Serbians (87 from the central region and 170 from the southern area) who have been analyzed for both uniparental genetic markers. The results showed that the extant inhabitants of the Balkan Peninsula have a homogeneous genetic background, despite their linguistic and cultural differences. The obtained data were compared with those of neighboring populations to detect possible relationships among groups. On the whole, the genetic variability of the Balkan populations seems to be due to an admixture process of European and Asian lineages in different proportions whose contributions constitute the current maternal and paternal genetic landscape

Morpho-Functional Evaluation of Full-Thickness Macular Holes by the Integration of Optical Coherence Tomography Angiography and Microperimetry

(1) Objective: To use optical coherence tomography angiography (OCTA) and microperimetry (MP) to evaluate the correlation between retinal structure and function in patients with idiopathic, full-thickness macular holes (FTMHs) (2) Methods: This prospective, observational study included 11 eyes of 10 patients with FTMHs evaluated before surgery using OCTA and MP. MP sensitivity maps were superimposed and registered on slabs corresponding to superficial capillary plexus (SCP) and deep capillary plexus (DCP) on OCTA, and on the outer plexiform layer (OPL) and the Henle fiber layer (HFL) complex in en face OCT. On these maps, mean retinal sensitivity was calculated at 2 degrees and 4 degrees, all centered on the FTMH. Cystic cavity extension was assessed on the slab corresponding to the OPL + HFL complex in en face OCT and DCP in OCTA using the Image J software (Version 1.49v; National Institutes of Health, Bethesda, MD, USA); (3) Results: Absolute scotomas were observed corresponding to the FTMH. Additionally, rings of relative scotoma in the perilesional area were detected and correlated to the cystic spaces on en face OCT and OCTA. There was a significant correlation between reduced retinal sensitivity at 2 degrees and 4 degrees diameters around the FTMH and the extension of cystic areas (p < 0.01). There was a significant correlation between the extension of cystic cavities and BCVA (p < 0.01). (4) Conclusions: Morpho-functional analysis of FTMH using OCTA and MP, and the correlation between vascular abnormalities and impaired retinal sensitivity, may provide new, useful information. This integrated evaluation of FTMH may be useful to determine the function-structure correlation before and after vitreoretinal surgery, in order to gain a better understanding of the functional consequences induced by the morphological alterations, assessing outcomes in a more objective way, and potentially adding new surgical prognostic factors

Expression of KNUCKLES in the Stem Cell Domain Is Required for Its Function in the Control of Floral Meristem Activity in Arabidopsis

In the model plant Arabidopsis thaliana, the zinc-finger transcription factor KNUCKLES (KNU) plays an important role in the termination of floral meristem activity, a process that is crucial for preventing the overgrowth of flowers. The KNU gene is activated in floral meristems by the floral organ identity factor AGAMOUS (AG), and it has been shown that both AG and KNU act in floral meristem control by directly repressing the stem cell regulator WUSCHEL (WUS), which leads to a loss of stem cell activity. When we re-examined the expression pattern of KNU in floral meristems, we found that KNU is expressed throughout the center of floral meristems, which includes, but is considerably broader than the WUS expression domain. We therefore hypothesized that KNU may have additional functions in the control of floral meristem activity. To test this, we employed a gene perturbation approach and knocked down KNU activity at different times and in different domains of the floral meristem. In these experiments we found that early expression in the stem cell domain, which is characterized by the expression of the key meristem regulatory gene CLAVATA3 (CLV3), is crucial for the establishment of KNU expression. The results of additional genetic and molecular analyses suggest that KNU represses floral meristem activity to a large extent by acting on CLV3. Thus, KNU might need to suppress the expression of several meristem regulators to terminate floral meristem activity efficiently

Producción y circulación de sentidos sobre el cambio cultural en la escuela : reconfiguraciones en torno a la cultura escrita, Argentina, 2003 - 2013

Orientada por la pregunta hacia dónde va la cultura escrita en la escuela, la presente tesis se propone el estudio del proceso de producción y circulación de sentidos sobre el cambio cultural y la escuela a propósito de las transformaciones culturales contemporáneas. Para ello, releva y analiza las prácticas discursivas producidas en el contexto argentino de la última década en torno a la cultura escolar, entendida como una construcción en la que se entremezclan las significaciones de la cultura político-normativa, la cultura de la intermediación pedagógica, y la cultura empírico-práctica de los docentes. Desde la perspectiva social, la tesis aporta a los esfuerzos por comprender los cambios en la educación, al ofrecer conocimientos que especifican el debate actual sobre el necesario cambio de la escuela a propósito de las resignificaciones de la cultura escrita. Desde el punto de vista de la investigación educativa, la tesis articula perspectivas que no siempre han entrado en diálogo en el estudio sobre la escuela y los docentes. Así, pretende discutir la tradición analítica que estudia la dinámica de la escuela y sus docentes asociada a recepciones conservadoras, resistentes o reactivas al cambio propuesto desde fuera de sus márgenes sino que, por el contrario, se propone incluirla en un proceso dinámico, abierto y deliberativo a través del cual se construyen, dialogan y confrontan las representaciones colectivas de diferentes grupos. Asimismo, propone contribuir al desarrollo de los estudios sobre la cultura escolar a partir de un abordaje que integra perspectivas de los estudios de la historia cultural de la educación con los de la historia de la lectura, ofreciendo un acceso alternativo al campo de lo escolar. Guided by the question what path is written culture taking in schools, this thesis intends to study the process of production and circulation of senses related to cultural change and school taking into account contemporary cultural transformations. To that aim, it gathers and analyses the discursive practices produced during the last decade of Argentinean school culture, which is understood as a construction that combines the significances of the normative-political culture, of the pedagogical intervention culture and of the teacher’s empirical-practical culture. From the social perspective, this thesis contributes to the efforts to understand the changes education has undergone, as it offers knowledge that specifies the current debate on the school’s necessary change according to the redefinitions of the written culture. From the educational investigation point of view, this thesis articulates perspectives that have not always been part of the studies on schools and teachers. Therefore, it aims at arguing the analytical tradition that studies the school and the teachers’ dynamic associated with conservative receptions, which are resistant or reactive when it comes to changes posed from outside their limits; and, on the contrary, it aims at including it in a dynamic, open and discursive process through which collective representations of different groups are built, discussed and compared. Additionally, it intends to contribute to the development of the studies into school culture from an approach that combines perspectives on the studies into the cultural history of education with studies into the history of reading, offering a variant access to the school field

Cambios recientes de la enseñanza de la producción escrita en la escuela primaria argentina

En este trabajo analizamos la enseñanza escolar de la escritura en el contexto argentino teniendo en cuenta los cambios y las continuidades que se produjeron a partir de 1990 y que se consolidaron en la primera década de este siglo respecto de décadas anteriores. El concepto de cultura escolar, específicamente a partir de su dimensión material puesta en juego en los cuadernos de clase, nos permite dar cuenta de los modos a través de los cuales fueron renovándose las propuestas de enseñanza de la escritura en las escuelas teniendo en cuenta los cambios curriculares y pedagógicos recientes en diálogo con las tradiciones y formas de enseñanza instaladas en las prácticas escolares. In this paper we analize the teaching of writing at school in Argentina. The context of the school is influenced by changes and continuities, which began in 1990 and were consolidated in the first decade of this century, as compared to previous decades. The concept of school culture, specifically through the material shown in copybooks, allows us to account for renewed teaching strategies of writing in schools, as demonstrated by the latest curricular and pedagogical changes, in accordance with traditions and ways of teaching ingrained in school practices