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Prion diseases, particularly sporadic cases, pose a challenge due to their complex nature and heterogeneity. The underlying mechanism of the spontaneous conversion from PrPC to PrPSc, the hallmark of prion diseases, remains elusive. To shed light on this process and the involvement of cofactors, we have developed an in vitro system that faithfully mimics spontaneous prion misfolding using minimal components. By employing this PMSA methodology and introducing an isoleucine residue at position 108 in mouse PrP, we successfully generated recombinant murine prion strains with distinct biochemical and biological properties. Our study aimed to explore the influence of a polyanionic cofactor in modulating strain selection and infectivity in de novo-generated synthetic prions. These results not only validate PMSA as a robust method for generating diverse bona fide recombinant prions but also emphasize the significance of cofactors in shaping specific prion conformers capable of crossing species barriers. Interestingly, once these conformers are established, our findings suggest that cofactors are not necessary for their infectivity. This research provides valuable insights into the propagation and maintenance of the pathobiological features of cross-species transmissible recombinant murine prion and highlights the intricate interplay between cofactors and prion strain characteristics.

Abstract Prion diseases are a group of rapidly progressing neurodegenerative disorders caused by the misfolding of the endogenous prion protein (PrPC) into a pathogenic form (PrPSc). This process, despite being the central event underlying these disorders, remains largely unknown at a molecular level, precluding the prediction of new potential outbreaks or interspecies transmission incidents. In this work, we present a method to generate bona fide recombinant prions de novo, allowing a comprehensive analysis of protein misfolding across a wide range of prion proteins from mammalian species. We study more than 380 different prion proteins from mammals and classify them according to their spontaneous misfolding propensity and their conformational variability. This study aims to address fundamental questions in the prion research field such as defining infectivity determinants, interspecies transmission barriers or the structural influence of specific amino acids and provide invaluable information for future diagnosis and therapy applications.

ABSTRACTAmong the transmissible spongiform encephalopathies (TSEs), chronic wasting disease (CWD) in cervids is now a rising concern in wildlife within Europe, after the detection of the first case in Norway in 2016, in a wild reindeer and until June 2022 a total of 34 cases were described in Norway, Sweden and Finland. The definite diagnosis is post-mortem, performed in target areas of the brain and lymph nodes. Samples are first screened using a rapid test and, if positive, confirmed by immunohistochemistry and Western immunoblotting. The study of the genetics of the prion protein gene, PRNP, has been proved to be a valuable tool for determining the relative susceptibility to TSEs. In the present study, the exon 3 of PRNP gene of 143 samples from red deer (Cervus elaphus) and fallow deer (Dama dama) of Portugal was analysed. Three single nucleotide polymorphisms (SNPs) were found in red deer – codon A136A, codon T98A, codon Q226E – and no sequence variation was detected in fallow deer. The low genetic diversity found in our samples is compatible with previous studies in Europe. The comparison with results from North America suggests that the free-ranging deer from our study may present susceptibility to CWD, although lack of experimental data and the necessity of continuous survey are necessary to evaluate these populations.

Abstract Among transmissible spongiform encephalopathies or prion diseases affecting humans, sporadic forms such as sporadic Creutzfeldt–Jakob disease are the vast majority. Unlike genetic or acquired forms of the disease, these idiopathic forms occur seemingly due to a random event of spontaneous misfolding of the cellular PrP (PrPC) into the pathogenic isoform (PrPSc). Currently, the molecular mechanisms that trigger and drive this event, which occurs in approximately one individual per million each year, remain completely unknown. Modelling this phenomenon in experimental settings is highly challenging due to its sporadic and rare occurrence. Previous attempts to model spontaneous prion misfolding in vitro have not been fully successful, as the spontaneous formation of prions is infrequent and stochastic, hindering the systematic study of the phenomenon. In this study, we present the first method that consistently induces spontaneous misfolding of recombinant PrP into bona fide prions within hours, providing unprecedented possibilities to investigate the mechanisms underlying sporadic prionopathies. By fine-tuning the Protein Misfolding Shaking Amplification method, which was initially developed to propagate recombinant prions, we have created a methodology that consistently produces spontaneously misfolded recombinant prions in 100% of the cases. Furthermore, this method gives rise to distinct strains and reveals the critical influence of charged surfaces in this process.

This article analyzes the effects of intangible capital on the productivity of Portuguese firms in the last decade. Intangible assets can increase the productivity of labor and productive factors. Although no consensus has been reached on standard principles and uniform methods for measuring intangible assets, the attempts of various investigators, such as those proposed in this research, pave the way for the development of a framework. To achieve this objective, a Cobb-Douglas production function was estimated at the firm level, where intangible capital is assumed as a productive factor. To perform a sectoral analysis, the model was estimated by activity sector. We also estimated the evolution of the contribution of intangible capital in two distinct periods 2010-14 (recession) and 2015-19 (recovery). The results obtained were to some extent expected, confirming the evidence of the positive effect of intangible assets on productivity. The intangible effect is greater in the sectors of Manufacturing and Construction, and inside the Manufacturing sector, the Textile industry is where the effect is larger. For the Trade and Business Services sector the effect is negative or null. Although intangible capital has a strong influence at the aggregate level, it has gradually lost its relevance. This result is understandable, given the low and decreasing levels of intangible investment and the continuous decrease in intangible capital during the decade.

Abstract Face recognition has become one of the most important modalities of biometrics in recent years. It widely utilises deep learning computer vision tools and adopts large collections of unconstrained face images of celebrities for training. Such choice of the data is related to its public availability when existing document compliant face image collections are hardly accessible due to security and privacy issues. Such inconsistency between the training data and deploy scenario may lead to a leak in performance in biometric systems, which are developed specifically for dealing with ID document compliant images. To mitigate this problem, we propose to regularise the training of the deep face recognition network with a specific sample mining strategy, which penalises the samples by their estimated quality. In addition to several considered quality metrics in recent work, we also expand our deep learning strategy to other sophisticated quality estimation methods and perform experiments to better understand the nature of quality sampling. Namely, we seek for the penalising manner (sampling character) that better satisfies the purpose of adapting deep learning face recognition for images of ID and travel documents. Extensive experiments demonstrate the efficiency of the approach for ID document compliant face images.

This study analyzes the relationship between innovation and financial constraints. To this end, a database extracted from the Community Innovation Survey (CIS) and the System of Business Accounts (SCIE) was used. The sample consisted of 24,679 active companies operating in Portugal in the manufacturing and service industry between 2008 and 2016. A Recursive Bivariate Probit Model (RPBM) was used for making estimates. When analyzing the relationship between innovation and financial constraints, the results reveal a negative relationship between the two, confirming that firms that are financially constrained are more limited in their investments in R&D, and innovation is less accessible to them. The severity of the effects of financial constraints is heterogeneous across economic activities, strongly affecting innovative industries, while service industries appear to be the least affected. It was also observed that larger companies are better able to innovate. There was a positive relationship between innovation and the variables sales and exports, indicating that innovation will positively affect the financial results of companies.

Introduction: Verbal and non-verbal communication skills are core competencies in medical practice and should be acquired and monitored in medical schools. However, their assessment poses a challenge. The aim of this study is to develop and assess the psychometric properties, validity and reliability of a communication assessment scale. Material and Methods: We developed a communication assessment scale, composed by five dimensions (Structure, Way of Questioning, Behavior and Posture, Clarity of information and Emotional dimension). Two focus groups and a development group, composed by faculty members and standardized patients experienced in assessment, were responsible for creating the scale. Results: The communication assessment scale was tested on 332 students from the 3rd and 6th year of medical school, with a total of 2754 assessments, performed by faculty members and standardized patients. A descriptive analysis, an exploratory factor analysis, a confirmatory factor analysis and a Cronbach’s alpha analysis to establish internal reliability were conducted. Discussion: The Minho Communication Assessment Scale can be effectively used by both faculty members and standardized patients, providing correct students assessment and relevant feedback to the students. The final Minho Communication Assessment Scale has a total of 19 items, being simple and intuitive to use. The exploratory factor analysis and confirmatory factor analysis results were satisfactory. Cronbach’s alpha value revealed high internal consistency of Minho Communication Assessment Scale. Conclusion: The final Minho Communication Assessment Scale proved to be simple to use and to have very good psychometric properties. Our results show that the Minho Communication Assessment Scale is a valid scale to assess communication skills which can be accurately replicated on objective structured clinical examinations focusing on communication.

Wasting disease in small ruminants is frequently detected at slaughterhouses. The wasting disorder is manifested by the deterioration of the nutritional and physiological state of the animal indicated by thinness, emaciation, and cachexia. Evidence of emaciation and cachexia, alone, are pathological conditions leading to carcass condemnation during an inspection. Several diseases are associated with a wasting condition, including scrapie, pseudotuberculosis, tuberculosis, paratuberculosis, Maedi Visna, and tumor diseases. On the other hand, parasitic diseases, nutrition disorders, exposure or ingestion of toxins, metabolic conditions, inadequate nutrition due to poor teeth, or poor alimentary diet are conditions contributing to poor body condition. Classical and atypical scrapie is naturally occurring transmissible spongiform encephalopathies in small ruminants. The etiological agent for each one is prions. However, each of these scrapie types is epidemiologically, pathologically, and biochemically different. Though atypical scrapie occurs at low incidence, it is consistently prevalent in the small ruminant population. Hence, it is advisable to include differential diagnosis of this disease, from other possibilities, as a cause of wasting conditions detected during meat inspection at the abattoir. This manuscript is a review of the measures in force at the abattoir for scrapie control, focusing on the differential diagnosis of gross lesions related to wasting conditions detected in small ruminants during meat inspection.

The identification of a person is a natural way to gain access to information or places. A face image is an essential element of visual validation. In this paper, we present the Card3DFace application, which captures a single-shot image of a person’s face. After reconstructing the 3D model of the head, the application generates several images from different perspectives, which, when printed on a card with a layer of lenticular lenses, produce a 3D visualization effect of the face. The image acquisition is achieved with a regular consumer 3D camera, either using plenoptic, stereo or time-of-flight technologies. This procedure aims to assist and improve the human visual recognition of ID cards and travel documents through an affordable and fast process while simultaneously increasing their security level. The whole system pipeline is analyzed and detailed in this paper. The results of the experiments performed with polycarbonate ID cards show that this end-to-end system is able to produce cards with realistic 3D visualization effects for humans.

Various modern security systems follow a tendency to simplify the usage of the existing biometric recognition solutions and embed them into ubiquitous portable devices. In this work, we continue the investigation and development of our method for securing identification documents. The original facial biometric template, which is extracted from the trusted frontal face image, is stored on the identification document in a secured personalized machine-readable code. Such document is protected from face photo manipulation and may be validated with an offline mobile application. We apply automatic methods of compressing the developed face descriptors to make the biometric validation system more suitable for mobile applications. As an additional contribution, we introduce several print-capture datasets that may be used for training and evaluating similar systems for mobile identification and travel documents validation.

Human beings have developed fantastic abilities to integrate information from various sensory sources exploring their inherent complementarity. Perceptual capabilities are therefore heightened, enabling, for instance, the well-known "cocktail party" and McGurk effects, i.e., speech disambiguation from a panoply of sound signals. This fusion ability is also key in refining the perception of sound source location, as in distinguishing whose voice is being heard in a group conversation. Furthermore, neuroscience has successfully identified the superior colliculus region in the brain as the one responsible for this modality fusion, with a handful of biological models having been proposed to approach its underlying neurophysiological process. Deriving inspiration from one of these models, this paper presents a methodology for effectively fusing correlated auditory and visual information for active speaker detection. Such an ability can have a wide range of applications, from teleconferencing systems to social robotics. The detection approach initially routes auditory and visual information through two specialized neural network structures. The resulting embeddings are fused via a novel layer based on the superior colliculus, whose topological structure emulates spatial neuron cross-mapping of unimodal perceptual fields. The validation process employed two publicly available datasets, with achieved results confirming and greatly surpassing initial expectations.

Transmissible Spongiform Encephalopathies (TSEs) or prion diseases are a fatal group of infectious, inherited and spontaneous neurodegenerative diseases affecting human and animals. They are caused by the conversion of cellular prion protein (PrPC) into a misfolded pathological isoform (PrPSc or prion- proteinaceous infectious particle) that self-propagates by conformational conversion of PrPC. Yet by an unknown mechanism, PrPC can fold into different PrPSc conformers that may result in different prion strains that display specific disease phenotype (incubation time, clinical signs and lesion profile). Although the pathways for neurodegeneration as well as the involvement of brain inflammation in these diseases are not well understood, the spongiform changes, neuronal loss, gliosis and accumulation of PrPSc are the characteristic neuropathological lesions. Scrapie affecting small ruminants was the first identified TSE and has been considered the archetype of prion diseases, though atypical and new animal prion diseases continue to emerge highlighting the importance to investigate the lesion profile in naturally affected animals. In this report, we review the neuropathology and the neuroinflammation of animal prion diseases in natural hosts from scrapie, going through the zoonotic bovine spongiform encephalopathy (BSE), the chronic wasting disease (CWD) to the newly identified camel prion disease (CPD).

Hip arthroscopy is useful in the treatment of several intra-articular pathologies, however, its use in high-energy hip and pelvis injuries raises concerns about fluid extravasion and stability of the pelvic ring. We present our arthroscopic surgical technique (initial access to the peripheral compartment) to remove intra-articular loose bodies and treat associated lesions, as well as our concerns with the technique, in case of a traumatic hip dislocation associated with a contralateral pelvic ring injury.

The genus Onchocerca encompasses parasitic nematodes including Onchocerca volvulus, causative agent of river blindness in humans, and the zoonotic Onchocerca lupi infecting dogs and cats. In dogs, O. lupi adult worms cause ocular lesions of various degrees while humans may bear the brunt of zoonotic onchocercosis with patients requiring neurosurgical intervention because of central nervous system localization of nematodes. Though the zoonotic potential of O. lupi has been well recognized from human cases in Europe, the United States and the Middle East, a proper therapy for curing this parasitic infection in dogs is lacking. To evaluate the efficacy of oxfendazole, 11 out of the 21 client-owned dogs (21/123; 17.1%) positive for skin-dwelling O. lupi microfilariae (mfs), were enrolled in the efficacy study and were treated with oxfendazole (50 mg/kg) per OS once a day for 5 (G2) or 10 (G3) consecutive days or were left untreated (G1). The efficacy of oxfendazole in the reduction of O. lupi mfs was evaluated by microfilarial count and by assessing the percentage of mfs reduction and mean microfilaricidal efficacy, whereas the efficacy in the reduction of ocular lesions was evaluated by ultrasound imaging. All dogs where subjected to follow-ups at 30 (D30), 90 (D90) and 180 (D180) days post-treatment. The percentage of reduction of mfs was 78% for G2 and 12.5% for G3 at D180. The mean microfilaricidal efficacy of oxfendazole in the treatment of canine onchocercosis by O. lupi at D30, D90 and D180 was 41%, 81% and 90%, in G2 and 40%, 65% and 70%, in G3, respectively. Retrobulbar lesions did not reduce from D0 to D180 in control group (dogs in G1), whereas all treated dogs (in G2 and G3) had slightly decreased ocular lesions. Percentage of reduction of ocular lesions by ultrasound examination was 50% and 47.5% in G2 and G3 at D180, respectively. Despite the decrease in ocular lesions in all treated dogs (G2 and G3), oxfendazole was ineffective in reducing ocular lesions and skin-dwelling O. lupi mfs in treated dogs (G2 and G3) in a six-month follow-up period. Here we discuss the need for more reliable diagnostic techniques and efficient treatment protocols to better plan future intervention strategies.

The existence of putatively painful situations to the fetus demands a careful evaluation of the issue of fetal pain. Several indirect approaches are used to evaluate the existence of fetal pain. Neurobiological studies showed that from the 30th week on, the anatomical and physiological system for pain transmission is already developed, with the connections from the periphery to the cortex being successively established. Stress responses to a painful stimulation are complex but they can be detected from the 16th week on. There is activation of the hypothalamus-pituitary-adrenal axis, autonomic nervous system and hemodynamic changes in response to nociceptive stimulation. In prematures exposed to pain there are significant increases of adrenaline, noradrenaline and cortisol, hemodynamic changes, motor reflexes and facial reactions. The changes induced by strong nociceptive stimulation of newborns have important postnatal consequences since they affect future reactions to noxious stimuli. Central sensitization and immaturity of the pain inhibitory system are the main neurobiological explanations for the increased pain. Detailed studies of the neurobiological mechanisms of the transmission of painful stimuli along with follow-up studies of the consequences of exposure to pain during the development of the fetus are necessary to fully understand fetal pain.

Obesity is increasing all over the world, its morbidity justifying a serious effort to improve the situation. Diet and physical exercise constitute major measures to fight obesity. We aimed to investigate the effect of acute exercise intensity over plasma insulin, growth hormone and somatostatin responses. Plasma levels of insulin, growth hormone, somatostatin and glucose were measured at baseline, after 15 minutes of moderate intensity exercise and after 15 minutes of high intensity exercise in a group of young healthy volunteers. Insulin, growth hormone and somatostatin were measured by immunoradioassay and glucose by a glucose oxidase method. After moderate intensity exercise plasma insulin levels tended to decrease, growth hormone tended to increase and somatostatin did not change. A similar period of high intensity exercise led to a similar decrease of plasma insulin, a much higher increase of growth hormone plasma level and no change of somatostatin. Glycemia suffered no significant change throughout the experiment. We conclude that hormonal changes induced by physical exercise depend on the intensity of exercise. When comparing moderate with high intensity exercise, a similar response of plasma insulin and a lower growth hormone/somatostatin ratio may support a healthier cardiovascular effect for moderate intensity exercise.