The Separability Problem in Molecular Quantum Systems: Information-Theoretic Framework for Atoms in Molecules.

Even though molecules are fundamentally quantum entities, the concept of a molecule retains certain classical attributes concerning its constituents. This includes the empirical separability of a molecule into its three-dimensional, rigid structure in Euclidean space, a framework often obtained through experimental methods like X-Ray crystallography. In this work, we delve into the mathematical implications of partitioning a molecule into its constituent parts using the widely recognized Atoms-In-Molecules (AIM) schemes, aiming to establish their validity within the framework of Information Theory concepts. We have uncovered information-theoretical justifications for employing some of the most prevalent AIM schemes in the field of Chemistry, including Hirshfeld (stockholder partitioning), Bader's (topological dissection), and the quantum approach (Hilbert's space definition). In the first approach we have applied the generalized principle of minimum relative entropy derived from the Sharma-Mittal two-parameter functional, avoiding the need for an arbitrary selection of reference promolecular atoms. Within the ambit of topological-information partitioning, we have demonstrated that the Fisher information of Bader's atoms conform to a comprehensive theory based on the Principle of Extreme Physical Information avoiding the need of employing the Schwinger's principle, which has been proven to be problematic. For the quantum approach we have presented information-theoretic justifications for conducting Löwdin symmetric transformations on the density matrix to form atomic Hilbert spaces generating orthonormal atomic orbitals with maximum occupancy for a given wavefunction.

La historia olvidada del alzhéimer: recordando a Oskar Fischer

Introducción: La Enfermedad de Alzheimer (EA), es una patología neurodegenerativa progresiva que afecta la memoria y otras funciones cognitivas. Hasta ahora no existen tratamientos curativos ni modificadores de la enfermedad, por lo que el manejo está centrado en la prevención y en el tratamiento de factores que puedan contribuir a su evolución; las herramientas farmacológicas son escasas y tienen efectos modestos en la ralentización de la enfermedad. Se propone realizar una breve biografía de Oskar Fischer, describir el conflicto con Alois Alzheimer que se identifica en documentos científicos y mencionar los principales elementos de la teoría de Oskar Fischer. Método: Se realizó una revisión narrativa en las bases de datos Scielo, PubMed y Lilacs, con los términos "Oskar Fischer" y se encontró quince artículos publicados entre 1906 a 2023, los cuales fueron resumidos por los autores GS y NR. El artículo fue posteriormente revisado por los demás autores. Resultados: Se organizaron en secciones, partiendo con una breve biografía del autor, su interacción con Alois Alzheimer y un resumen de su teoría; lo descrito por Oskar Fischer en términos de las estructuras de placas y ovillos se considera como una de las principales teorías fisiopatológicas de la EA. Conclusiones: Oskar Fisher hizo un aporte invaluable y planteó conceptos clásicos con respecto a la EA, que, si bien no le valieron para ser reconocido en la posteridad, han permitido que en las investigaciones posteriores sea de gran importancia repensar estos conceptos e incluir otras posibilidades e hipótesis, para continuar en la profundización del conocimiento de la enfermedad.

Introduction: Alzheimer's disease (AD) is a progressive neurodegenerative pathology that affects memory and other cognitive functions. Until now, there are no curative or disease-modifying treatments, so management is focused on prevention and treatment of factors that may contribute to its evolution; pharmacological tools are scarce and have modest effects in slowing the disease. It is proposed to make a brief biography of Oskar Fischer, describe the conflict with Alois Alzheimer that is identified in scientific documents and mention the main elements of Oskar Fischer's theory. Method: A narrative review was carried out in the Scielo, PubMed and Lilacs databases, with the terms "Oskar Fischer" and fifteen articles published between 1906 and 2023 were found, which were summarized by the authors GS and NR. The article was subsequently reviewed by the other authors. Results: They were organized in sections, starting with a brief biography of the author, his interaction with Alois Alzheimer and a summary of his theory; what was described by Oskar Fischer in terms of the structures of plaques and tangles is considered one of the main pathophysiological theories of AD. Conclusions: Oskar Fisher made an invaluable contribution and raised classic concepts regarding AD, which, although they did not earn him recognition in posterity, have allowed subsequent research to be of great importance to rethink these concepts and include other possibilities and hypotheses, to continue deepening the knowledge of the disease.

Comparison of Prognostic Performance between Fisher and Modified Fisher Scales for Patients with Aneurysmal Subarachnoid Hemorrhage / Comparação do desempenho prognóstico entre as escalas Fisher e Fisher modificada para pacientes com hemorragia subaracnóidea aneurismática

Objective The present study aims to assess and compare the prognostic value of these two scales for predicting mortality. Method We reviewed 172 patients with aneurysmal subarachnoid hemorrhage, who were followed-up for 6 months. The Fisher and modified Fisher scales were evaluated for the prediction of mortality using logistic regressions. Results The Fisher scale was associated with mortality (odds ratio [OR]: 2; 95% confidence interval [CI]: 1.09­4.05) in the multivariate analysis. The modified Fisher scale was not associated with mortality in the multivariate analysis (OR: 1.39; 95% CI: 0.9­2.29), nor in the univariate analysis (OR: 1.24; 95%CI: 0.87­1.86). There was no significant association between Fisher score and unfavorable functional outcomes (mRS > 2) in the univariate analysis (OR: 1.33; 95%CI: 0.92­1.92), nor in the multivariate analysis (OR: 1.37; 95%CI: 0.92­2.05). There was no significant association between modified Fisher scores and unfavorable functional outcomes in the univariate analysis (OR: 1.16; 95%CI: 0.88­1.52). There was also no significant association in the multivariate analysis (OR: 1.18; 95%CI: 0.88­1.57). Conclusion Only the Fisher scale was associated with mortality. Neither of the two scales was associated with unfavorable functional outcomes (mRS > 2).

Objetivo O presente estudo tem como objetivo avaliar e comparar o valor prognós tico dessas duas escalas para predizer mortalidade. Método Revisamos 172 pacientes com hemorragia subaracnóidea aneurismática, acompanhados por 6 meses. As escalas de Fisher e modificada de Fisher foram avaliadas para a previsão de mortalidade usando regressões logísticas. Resultados A escala de Fisher foi associada à mortalidade (odds ratio [OR]: 2; intervalo de confiança [IC] 95%: 1.09­4.05) na análise multivariada. A escala Fisher modificada não foi associada à mortalidade na análise multivariada (OR: 1.39; IC95%: 0.9­2.29), nem na análise univariada (OR: 1.24; IC95%: 0.87­1.86). Não houve associação significativa entre o escore de Fisher e resultados funcionais desfavoráveis (mRS > 2) na análise univariada (OR: 1.33; IC95%: 0.92­1.92), nem na análise multivariada (OR: 1.37; IC95%: 0.92­2.05). Não houve associação significativa entre os escores modificados de Fisher e resultados funcionais desfavoráveis na análise univariada (OR: 1.16; IC95%: 0.88­1.52). Também não houve associação significativa na análise multivariada (OR: 1.18; IC95%: 0.88­1.57). Conclusão Apenas a escala de Fisher foi associada à mortalidade. Nenhuma das duas escalas foi associada a resultados funcionais desfavoráveis (mRS > 2).

Fisher and Shannon Functionals for Hyperbolic Diffusion.

The complexity measure for the distribution in space-time of a finite-velocity diffusion process is calculated. Numerical results are presented for the calculation of Fisher's information, Shannon's entropy, and the Cramér-Rao inequality, all of which are associated with a positively normalized solution to the telegrapher's equation. In the framework of hyperbolic diffusion, the non-local Fisher's information with the x-parameter is related to the local Fisher's information with the t-parameter. A perturbation theory is presented to calculate Shannon's entropy of the telegrapher's equation at long times, as well as a toy model to describe the system as an attenuated wave in the ballistic regime (short times).

Long-term female bias in sex ratios across life stages of Harpy Eagle, a large raptor exhibiting reverse sexual size dimorphism.

The primary (PSR), secondary (SSR) and adult (ASR) sex ratios of sexually reproducing organisms influence their life histories. Species exhibiting reversed sexual size dimorphism (RSD) may imply a higher cost of female production or lower female survival, thus generating biases in PSR, SSR and/or ASR towards males. The Harpy Eagle is the world's largest eagle exhibiting RSD. This species is found in the Neotropical region and is currently threatened with extinction. We used molecular markers to determine the sex of 309 Harpy Eagles spanning different life stages-eaglets, subadults and adults-from 1904 to 2021 within the Amazon Rainforest and Atlantic Forest. Sex ratios for all life stages revealed a female-biased deviation across all periods and regions. Our results suggest that the population bias towards females is an evolutionary ecological pattern of this species, and SSR and ASR likely emerged from the PSR. This natural bias towards females may be compensated by an earlier sexual maturation age of males, implying a longer reproductive lifespan and a higher proportion of sexually active males. A better understanding of the Harpy Eagle's life history can contribute to understanding sex-role evolution and enable more appropriate conservation strategies for the species.

Quantifying Soil Complexity Using Fisher Shannon Method on 3D X-ray Computed Tomography Scans.

The conversion of native forest into agricultural land, which is common in many parts of the world, poses important questions regarding soil degradation, demanding further efforts to better understand the effect of land use change on soil functions. With the advent of 3D computed tomography techniques and computing power, new methods are becoming available to address this question. In this direction, in the current work we implement a modification of the Fisher-Shannon method, borrowed from information theory, to quantify the complexity of twelve 3D CT soil samples from a sugarcane plantation and twelve samples from a nearby native Atlantic forest in northeastern Brazil. The distinction found between the samples from the sugar plantation and the Atlantic forest site is quite pronounced. The results at the level of 91.7% accuracy were obtained considering the complexity in the Fisher-Shannon plane. Atlantic forest samples are found to be generally more complex than those from the sugar plantation.

Quantum Information Entropy for Another Class of New Proposed Hyperbolic Potentials.

In this work, we investigate the Shannon entropy of four recently proposed hyperbolic potentials through studying position and momentum entropies. Our analysis reveals that the wave functions of the single-well potentials U0,3 exhibit greater localization compared to the double-well potentials U1,2. This difference in localization arises from the depths of the single- and double-well potentials. Specifically, we observe that the position entropy density shows higher localization for the single-well potentials, while their momentum probability density becomes more delocalized. Conversely, the double-well potentials demonstrate the opposite behavior, with position entropy density being less localized and momentum probability density showing increased localization. Notably, our study also involves examining the Bialynicki-Birula and Mycielski (BBM) inequality, where we find that the Shannon entropies still satisfy this inequality for varying depths u¯. An intriguing observation is that the sum of position and momentum entropies increases with the variable u¯ for potentials U1,2,3, while for U0, the sum decreases with u¯. Additionally, the sum of the cases U0 and U3 almost remains constant within the relative value 0.01 as u¯ increases. Our study provides valuable insights into the Shannon entropy behavior for these hyperbolic potentials, shedding light on their localization characteristics and their relation to the potential depths. Finally, we extend our analysis to the Fisher entropy F¯x and find that it increases with the depth u¯ of the potential wells but F¯p decreases with the depth.

Quantum Information Entropy for a Hyperbolic Double Well Potential in the Fractional Schrödinger Equation.

In this study, we investigate the position and momentum Shannon entropy, denoted as Sx and Sp, respectively, in the context of the fractional Schrödinger equation (FSE) for a hyperbolic double well potential (HDWP). We explore various values of the fractional derivative represented by k in our analysis. Our findings reveal intriguing behavior concerning the localization properties of the position entropy density, ρs(x), and the momentum entropy density, ρs(p), for low-lying states. Specifically, as the fractional derivative k decreases, ρs(x) becomes more localized, whereas ρs(p) becomes more delocalized. Moreover, we observe that as the derivative k decreases, the position entropy Sx decreases, while the momentum entropy Sp increases. In particular, the sum of these entropies consistently increases with decreasing fractional derivative k. It is noteworthy that, despite the increase in position Shannon entropy Sx and the decrease in momentum Shannon entropy Sp with an increase in the depth u of the HDWP, the Beckner-Bialynicki-Birula-Mycielski (BBM) inequality relation remains satisfied. Furthermore, we examine the Fisher entropy and its dependence on the depth u of the HDWP and the fractional derivative k. Our results indicate that the Fisher entropy increases as the depth u of the HDWP is increased and the fractional derivative k is decreased.

A model based on a multivariate classification for assessing impacts on water quality in a DOCE river watershed after the Fundão tailings dam failure.

The main purpose of this study was to build multivariate classification models using water quality monitoring data for the hydrographic basin of the Gualaxo do Norte River, Minas Gerais state, Brazil, which was impacted in 2015 by the rupture of a containment structure for iron ore tailings. A total of 27 points were evaluated, covering areas affected and unaffected by the disaster, with monitoring of chemical, physical, and microbiological variables during the period from July 2016 to June 2017. Multivariate classification techniques were applied to the data, with the aim of developing models to determine when the impacted locations would present characteristics equivalent to those existing prior to the rupture. Classification models constructed using PLS-DA and LDA were able to predict three classes: unaffected main river, affected main river, and tributaries. The first technique was able to clearly differentiate the three classes for the data evaluated, achieving averages corresponding to 90% accuracy. The second method was consistent with the first, identifying the chloride content, conductivity, turbidity, and alkalinity as discriminatory variables, among those monitored, with the relationships among the parameters being coherent with the environmental conditions of the region. The model, with a correct classification rate of 91.67%, enabled identification of the behavior of new samples, using only these easily measured variables. In summary, application of the multivariate statistical tools allowed the development of models capable of providing information about the recovery process of an ecosystem impacted by the greatest environmental disaster to have occurred in Brazil.

-I fish, therefore I monitor: Participatory monitoring to assess inland small-scale fisheries.

Analysis of small-scale inland fisheries (SSIFs) is often highly dispersed and tends not reflect the true magnitude of their contribution to society. This is partly due to the insufficient attention given to this sector by the relevant authorities, in addition to its highly diverse characteristics, with complex patterns of operation in a wide range of systems, often in remote areas. Here, by integrating fishers as participatory fishery monitors, we provide fishery-dependent estimates of yields, the biological attributes of the fish species, and the spatiotemporal dynamics of the fisheries of lakes on the floodplain of the São Francisco basin in northeastern Brazil. As the fishers were willing participates in the monitoring, the results revealed well-structured artisanal fishing activities, with the lake system providing high-profile fish harvests from both monthly and annual perspectives. The spatial distribution of fishing effort reflected the adaptation of the fishers to the flood cycle of the river, in order to maintain high fishery productivity throughout the year. The results also indicate that participatory monitoring can help to overcome knowledge gaps and provide a database that is readily applicable to management needs at both local and regional scales. As Brazil is one few world's nations that no longer have national fishing monitoring program, participatory monitoring represents a low-cost solution for the credible and useful data on small-scale fisheries. It would thus appear to be extremely worthwhile to invest in the empowerment of communities in order to overcome the historic vulnerability of productive sector and the food security of the populations that depend on these fisheries.

Guillain-Barré syndrome associated with COVID-19: A systematic review.

With the outbreak of coronavirus disease 2019 (COVID-19), the whole world was impacted by a pandemic. With the passage of time and knowledge about the dynamics and viral propagation of this disease, the short-, medium- and long-term repercussions are still being discovered. During this period, it has been learned that various manifestations of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can affect the nervous system. In recent months, a variety of studies and case reports have proposed an association between COVID-19 and Guillain-Barré syndrome (GBS). The present work aims to systematically review the publications available to date to verify the relationship between these two pathologies and the characteristics of post-COVID GBS. There were 156 studies included in this work, resulting in a total of 436 patients. The findings show a mean age of the patients of 61,38 years and a male majority. The GBS symptoms began on average 19 days after the onset of COVID-19 infection. Regarding GBS, the main manifestations found included generalized weakness, reflex reduction, facial paresis/paralysis and hypoesthesia. As expected, the most common result in cerebrospinal fluid (CSF) analysis was albuminocytological dissociation. A pattern of blood analysis findings common to all patients was not observed due to non-standardization of case reports. Regarding electrodiagnostic studies, acute inflammatory demyelinating polyneuropathy (AIDP) appeared as the most common subtype of GBS in this study. There have been reports, to a lesser extent, of acute motor axonal neuropathy (AMAN), acute sensorimotor axonal neuropathy (AMSAN), the pharyngeal-cervical-brachial variant (PCB), and Miller-Fisher syndrome (MFS). The GBS treatment used was mainly intravenous immunoglobulin (IVIG) and plasma exchange (PLEX). Therefore, the present study reports a high prevalence of hospitalization and intensive care units ICU admissions, conjecturing a relationship between the development of GBS and the severity of COVID-19. Despite the severity, most patients showed improvement in GBS symptoms after treatment, and their residual symptoms did not include motor involvement. Therefore, the development of GBS seems to be related to COVID-19 infection, as reported by the present systematic review.

Evaluation of pediatric patients presenting with acute-onset unilateral transient acquired blepharoptosis / Avaliação de pacientes pediátricos apresentando blefaroptose transitória unilateral de início agudo

ABSTRACT Purpose: To evaluate the clinical features of pediatric patients with acute-onset, unilateral transient acquired blepharoptosis. Methods: In this retrospective study, the clinical records of patients between April 2015 and June 2020 were reviewed for evaluation of demographic features, accompanying neurological and ophthalmologic manifestations, symptom duration, etiological cause, and imaging findings. Patients with congenital and acquired blepharoptosis with chronic etiologies were excluded. Results: Sixteen pediatric patients (10 boys and 6 girls) with acquired acute-onset unilateral transient blepharoptosis were included in this study. The patients' mean age was 6.93 ± 3.16 years. The most commonly identified etiological cause was trauma in 7 patients (43.75%) and infection (para-infection) in 5 patients (31.25%). In addition, Miller Fisher syndrome, Horner syndrome secondary to neuroblastoma, acquired Brown's syndrome, and pseudotumor cerebri were identified as etiological causes in one patient each. Additional ocular findings accompanied blepharoptosis in 7 patients (58.33%). Blepharoptosis spontaneously resolved, without treatment, in all the patients, except those with Miller Fisher syndrome, neuroblastoma, and pseudotumor cerebri. None of the patients required surgical treatment and had ocular morbidities such as amblyopia. Conclusion: This study demonstrated that acute-onset unilateral transient blepharoptosis, which is rare in childhood, may regress without the need for surgical treatment in the pediatric population. However, serious pathologies that require treatment may present with blepharoptosis.

RESUMO Objetivo: Avaliar as características clínicas de pacientes pediátricos com blefaroptose adquirida unilateral, transitória e de início agudo. Métodos: Neste estudo retrospectivo, foram revisados prontuários clínicos entre abril de 2015 e junho de 2020. Os pacientes foram avaliados em termos de características demográficas, manifestações neurológicas e oftalmológicas associadas, duração dos sintomas, etiologia e achados de imagem. Foram excluídos pacientes com blefaroptose congênita e com blefaroptose adquirida de etiologia crônica. Resultados: Foram incluídos neste estudo 16 pacientes pediátricos (10 masculinos e 6 femininos) com blefaroptose adquirida transitória unilateral de início agudo. A média de idade dos pacientes foi de 6,93 ± 3,16 anos. As causas etiológicas mais comumente identificadas foram trauma em 7 pacientes (43,75%) e infecção (casos parainfecciosos) em 5 pacientes (31,25%). Além disso, a síndrome de Miller-Fisher, a síndrome de Horner secundária a neuroblastoma, a síndrome de Brown adquirida e pseudotumor cerebral foram determinados como causas etiológicas em um paciente cada uma. Achados oculares adicionais estavam associados à blefaroptose em 7 pacientes (58,33%). Foi observada a resolução espontânea da blefaroptose, sem tratamento, em todos os pacientes, exceto nos pacientes com síndrome de Miller-Fisher, neuroblastoma e pseudotumor cerebral. Nenhum paciente precisou de tratamento cirúrgico. Morbidades oculares, como ambliopia, não foram encontradas em nenhum paciente. Conclusão: Este estudo demonstrou que a blefaroptose transitória unilateral de início agudo, rara na infância, pode regredir sem a necessidade de tratamento cirúrgico na população pediátrica. No entanto, também não deve ser esquecido que patologias graves que requerem tratamento podem se apresentar com blefaroptose.

Quantum Information Entropy of Hyperbolic Potentials in Fractional Schrödinger Equation.

In this work we have studied the Shannon information entropy for two hyperbolic single-well potentials in the fractional Schrödinger equation (the fractional derivative number (0

Miller-Fisher syndrome after first dose of Oxford/AstraZeneca coronavirus disease 2019 vaccine: a case report.

INTRODUCTION: Miller-Fisher Syndrome (MFS) is a variant of Guillain-Barré syndrome (GBS), an acute immune-mediated neuropathy, which manifests as a rapidly evolving areflex motor paralysis. This syndrome presents as a classic triad: ophthalmoplegia, areflexia, and ataxia. MFS is usually benign and self-limited. CASE REPORT: A Caucasian patient was admitted to our hospital with the flu, loss of bilateral strength in the lower limbs and upper limbs and sudden-onset ataxia 7 days after receiving a first dose of the Oxford/AstraZeneca COVID-19 vaccine. On neurological examination, the patient had Glasgow Coma Scale score of 15, with absence of meningeal signs; negative Babinski sign; grade 2 strength in the lower limbs and grade 4 strength in the upper limbs; axial and appendicular cerebellar ataxia; and peripheral facial diparesis predominantly on the right, without conjugate gaze deviation. Cerebrospinal fluid (CSF) was collected on admission, and analysis revealed albuminocytological dissociation with CSF protein of 148.9 mg/dL; leukocytes, 1; chlorine, 122; glucose, 65 mg/mL; red cells, 2; and non-reactive venereal disease research laboratory test result. The COVID-19 IgG/IgM rapid immunological test was negative. Electroneuromyography revealed a recent moderate-grade and primarily sensory and motor demyelinating polyneuropathy with associated proximal motor block. DISCUSSION AND CONCLUSION: Miller-Fisher Syndrome may be related to events other than infections prior to neuropathy, as in the case reported here. The patient presented strong correlations with findings for MFS reported in the literature, such as the clinical condition, the results of electroneuromyography, and results of the CSF analysis typical for MFS. When treatment was provided as proposed in the literature, the disease evolved with improvement. Ultimately, the diagnosis of incomplete MFS was made, including acute ataxic neuropathy (without ophthalmoplegia).

Guillain-Barré Syndrome and Miller Fisher Syndrome in Association With an Arboviral Outbreak: A Brazilian Case Series.

Introduction: Guillain-Barré syndrome (GBS) in association with arboviruses, such as Zika, chikungunya, and dengue, has been previously documented; however, Miller-Fisher Syndrome (MFS) and other GBS subtypes are rarely reported. Methods: We identified a series of GBS and MFS cases that were followed during the Zika virus outbreak in Salvador, Brazil (2015-2016). Blood and CSF samples were collected for virus diagnosis. In addition, serological studies to verify previous arboviral infection and electromyography (EMG) were performed. Results: Of the 14 patients enrolled, 10 were diagnosed with GBS, including three GBS subtypes (two cases of bifacial weakness with paresthesia and one case of paraparetic GBS), and four as MFS. IgM antibodies against one or more of three arboviruses were present in 11 (78.6%) patients: anti-zika IgM positivity in eight (57%), anti-Chikungunya IgM in three (21%), and anti-Dengue in one (7%) individual. A single case was positive for both anti-Dengue IgM and anti-Chikungunya IgM, suggesting co-infection. EMG revealed an AIDP pattern in all nine patients analyzed. Conclusion: The current case series contributes to our knowledge on the clinical presentation of arbovirus-associated GBS and its subtypes, including MFS, and serves as an alert to clinicians and other healthcare professionals in regions affected by arbovirus outbreaks. We highlight the importance of recognizing arboviruses in diagnosing GBS and its subtypes.

Síndrome de Miller-Fisher durante el embarazo

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Miller-Fisher syndrome is a rare, acute, autoimmune, demyelinating disorder which is considered a variant of Guillain-Barré syndrome. The pathologic mechanism is unclear, but acute demyelinating polyneuropathies may be triggered by bacterial or viral infections, major surgical interventions, or vaccination. Pregnancy may be a trigger of the immune response causing the onset of the syndrome. Miller-Fisher syndrome is characterized by acute onset, with predominant involvement of the facial and cranial nerves resulting in ophthalmoparesis, ataxia, and areflexia/hyporeflexia. Diagnosis is based on clinical suspicion together with the determination of specific ganglioside antibodies and other laboratory and imaging tests. Treatment consists of intravenous immunoglobulin and plasmapheresis, together with supportive measures. There are few reports of the syndrome occurring in pregnant women. A case of Miller-Fisher syndrome during pregnancy is presented.

INTRODUCTION Miller-Fisher syndrome (MFS) is a rare disorder that is characterized by acute onset of ophthalmoparesis, ataxia and hyporeflexia / areflexia(1). It was recognized 60 years ago as a variant of Guillain-Barré syndrome (GBS). The annual incidence is 0.09 per 100,000 persons and affects more males than females with a 2:1 ratio(2). GBS usually follows Campylobacter jenuni, cytomegalovirus, Epstein-Barr and influenza virus infections or secondary to major surgery, pregnancy, or vaccination(3,4). MFS accounts for 5%-10% of GBS cases and may have a major autoimmune component due to the presence of anti-ganglioside antibodies. During the acute phase of the disease, these antibodies have a diagnostic sensitivity and specificity of 92% and 97%, respectively(5). MFS during pregnancy is rare and there are only reports of 5 cases in pregnant women. A case of Miller-Fisher syndrome during pregnancy is presented. CLINICAL CASE The patient was 16 years old, primigravida of 20 weeks, who was referred for presenting nausea and incoercible vomiting of five days of evolution, accompanied by double vision, generalized weakness, ataxia,

Disfagia e Disfonia em um caso de Síndrome de Miller Fisher: Avaliação fonoaudiológica / Dysphagia and Dysphonia in a case of Miller Fisher Syndrome: Speech therapy evaluation

RESUMO Relato de caso de um paciente do sexo masculino internado no pronto socorro de um hospital com síndrome de Miller Fisher (SMF). A SMF é caracterizada pela presença de uma tríade de sinais: oftalmoparesia, arreflexia e ataxia, podendo apresentar outros sinais menos frequentes como alterações de fala e de deglutição. A partir da avaliação fonoaudiológica foi possível identificar disfagia orofaríngea de grau grave, hipernasalidade vocal e outras alterações fonoarticulatorias. O paciente apresentou boa evolução a partir de uma terapêutica multiprofissional integrada, incluído atendimento fonoaudiológico.

SUMMARY The case report of a male patient admitted to the emergency hospital with the diagnosis of Miller Fisher syndrome (MF), is presented. MFS is characterized by the presence of a triad of signs: ophthalmoparesis, areflexia and ataxia, and may present other less frequent signs such as speech and swallowing disorders. On the basis of findings during the speech therapy evaluation it was possible to identify severe oropharyngeal dysphagia, vocal hypernasality and other speech disorders. The patient presented a good evolution following an integrated multi-professional treatment program, including speech-language therapy.

An Atypical Case of Miller Fisher Syndrome with Multiple Autoimmunity.

Miller Fisher syndrome (MFS) is a rare variant of Guillain-Barré syndrome that is characterised by ataxia, ophthalmoplegia, and areflexia. Its relation with other autoimmune diseases is scarcely found in the literature, and in those few cases, treatment has been especially difficult. We report a case of a 28-year-old woman who presented with ophthalmoplegia and ptosis, later developing facial palsy and hyporeflexia. She had positive GD1a, GT1a, GQ1b antibodies confirming MFS. She also had positive antinuclear and lupus anticoagulant antibodies confirming antiphospholipid syndrome. She had a mild clinical course. MFS can present with multiple autoimmunity; it is unclear if there is cross-reactivity due to myelin damage.

[Clinical cases of Guillain-Barré and Miller-Fisher syndromes linked to COVID-19]. / Casos clínicos de los síndromes de Guillain-Barré y Miller-Fisher relacionados con la COVID-19.

coronavirus disease 2019 (COVID-19), caused by the new coronavirus SARS-CoV-2, has been associated with the development of neurological diseases such as Guillain-Barré syndrome (GBS) and its variants. In the present work, two cases of demyelinating syndromes associated with COVID-19 are reported. Clinical cases: 53-year-old male with GBS and and 29-year-old female with Miller-Fisher syndrome (MFS) variant, respectively. Both patients presented the classic neurological signs and symptoms of demyelinating polyneuropathy that characterizes the syndromes. From the paraclinical biochemical tests, the increase of proteins in cerebrospinal fluid was distinctive. The positivity of the RT-qPCR for SARS-CoV-2 suggested the association of GBS and MFS with COVID-19. Both patients were treated with intravenous immunoglobulin showing improvement. Electromyography performed weeks ahead still showed chronic demyelinating involvement. Conclusion: The cases of GBS and MFS, along with other similar cases reported around the world, provide further evidence for SARS-CoV-2 as a new possible etiology of these rare neurological diseases.

Introducción: la enfermedad por coronavirus del 2019 (COVID-19), causada por el nuevo coronavirus SARS-CoV-2, se ha asociado con el desarrollo de enfermedades neurológicas como el síndrome de Guillain-Barré (SGB) y sus variantes. En el presente trabajo se reportan dos casos de síndromes desmielizantes asociados con la COVID-19. Casos clínicos: hombre de 53 años con SGB y mujer de 29 años con la variante del síndrome de Miller-Fisher (SMF), respectivamente. Ambos presentaron los signos y síntomas neurológicos clásicos de polineuropatía desmielinizante que caracterizan a estos síndromes. De las pruebas bioquímicas paraclínicas, el aumento de proteínas en líquido cefalorraquídeo fue distintiva. La positividad de la RT-qPCR para el SARS-CoV-2 indicó la asociación de los SGB y SMF con la COVID-19. Ambos pacientes se trataron con inmunoglobulina intravenosa y mostraron mejoría. La electromiografía realizada en semanas posteriores aún mostraba afectación desmielinizante crónica. Conclusión: los casos de los SGB y SMF, junto con otros casos similares reportados en todo el mundo, proporcionan más evidencia para el SARS-CoV-2 como nueva posible etiología de estas raras enfermedades neurológicas.

Information-Theoretic Aspects of Location Parameter Estimation under Skew-Normal Settings.

In several applications, the assumption of normality is often violated in data with some level of skewness, so skewness affects the mean's estimation. The class of skew-normal distributions is considered, given their flexibility for modeling data with asymmetry parameter. In this paper, we considered two location parameter (µ) estimation methods in the skew-normal setting, where the coefficient of variation and the skewness parameter are known. Specifically, the least square estimator (LSE) and the best unbiased estimator (BUE) for µ are considered. The properties for BUE (which dominates LSE) using classic theorems of information theory are explored, which provides a way to measure the uncertainty of location parameter estimations. Specifically, inequalities based on convexity property enable obtaining lower and upper bounds for differential entropy and Fisher information. Some simulations illustrate the behavior of differential entropy and Fisher information bounds.