Towards a Functional Explanation of the Connectivity LGN - V1

The principles behind the connectivity between LGN and V1 are not well understood. Models have to explain two basic experimental trends: (i) the combination of thalamic responses is local and it gives rise to a variety of oriented Gabor-like receptive felds in V1 [1], and (ii) these filters are spatially organized in orientation maps [2]. Competing explanations of orientation maps use purely geometrical arguments such as optimal wiring or packing from LGN [3-5], but they make no explicit reference to visual function. On the other hand, explanations based on func- tional arguments such as maximum information transference (infomax) [6,7] usually neglect a potential contribution from LGN local circuitry. In this work we explore the abil- ity of the conventional functional arguments (infomax and variants), to derive both trends simultaneously assuming a plausible sampling model linking the retina to the LGN [8], as opposed to previous attempts operating from the retina. Consistently with other aspects of human vi- sion [14-16], additional constraints should be added to plain infomax to understand the second trend of the LGN-V1 con- nectivity. Possibilities include energy budget [11], wiring constraints [8], or error minimization in noisy systems, ei- ther linear [16] or nonlinear [14, 15]. In particular, consideration of high noise (neglected here) would favor the redundancy in the prediction (which would be required to match the relations between spatially neighbor neurons in the same orientation domain)

Novel RNA viruses from the Atlantic Ocean: Ecogenomics, biogeography, and total virioplankton mass contribution from surface to the deep ocean

Marine viruses play a major role in the energy and nutrient cycle and affect the evolution of their hosts. Despite their importance, there is still little knowledge about RNA viruses. Here, we have explored the Atlantic Ocean, from surface to deep (4.296 m), and used viromics and quantitative methods to unveil the genomics, biogeography, and the mass contribution of RNA viruses to the total viroplankton. A total of 2481 putative RNA viral contigs (>500 bp) and 107 larger bona fide RNA viral genomes (>2.5 kb) were identified; 88 of them representing novel viruses belonging mostly to two clades: Yangshan assemblage (sister clade to the class Alsuviricetes) and Nodaviridae. These viruses were highly endemic and locally abundant, with little or no presence in other oceans since only ≈15% of them were found in at least one of the Tara sampling metatranscriptomes. Quantitative data indicated that the abundance of RNA viruses in the surface and deep chlorophyll maximum zone was within ≈106 VLP/mL representing a potential contribution of 5.2%–24.4% to the total viroplankton community (DNA and RNA viruses), with DNA viruses being the predominant members (≈107 VLP/mL). However, for the deep sample, the observed trend was the opposite, although as further discussed, several biases should be considered. Together these results contribute to our understanding of the diversity, abundance, and distribution of RNA viruses in the oceans and provide a basis for further investigation into their ecological roles and biogeography.This work was supported by the Generalitat Valenciana ACIF2020 grant and by the research grants funded by Spanish Ministry of Science and Innovation (refs. RTI2018-094248-B-I00 and PID2021-125175OB-I00), and by the Gordon and Moore Foundation (ref. 5334)

Circadian rhythms of proliferation events in two mouse carcinomas

We studied the index of DNA synthesis (DNAs) of two cellular carcinomas: the hepatocellular ES12a and the mammary TN60 of mice, throughout one circadian cycle. In the results, we observed that both tumors have circadian rhythms (CRs), but the peaks of DNAs vary. Besides, the mean of DNAs along 24 h shows significative differences, the TN60 has higher values than the ES12a. These observed CR in the DNAs index in both carcinomas mean that, at least in partly, the proliferation of cancer cells can be regulated by endocrine factor as it normally occurs in ordinary cells. The big problem we can find for the chronopharmacology is that it is impossible to know in advance the rate of proliferation of each tumor.Fil: Garcia, Marcela. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: Andrini, Laura Beatríz. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: Martinez, Marina. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; ArgentinaFil: Inda, Ana. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Palma, Maria Belen. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Miriuka, Santiago Gabriel. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Errecalde, Ana Lia. Universidad Nacional de la Plata. Facultad de Ciencias Médicas; Argentin

Suffering and personal growth in coping with illness

En este número de Anales del Sistema Sanitario de Navarra se publican tres estudios diferentes que reflejan las distintas caras del sufrimiento ante la enfermedad. Uno de ellos trata sobre el sufrimiento del paciente que tiene dificultades para adaptarse al trasplante cardiaco, otro versa sobre el sufrimiento de la familia (en este caso, de los padres de niños oncológicos), y un tercer artículo aborda el sufrimiento del profesional, médico de Atención Primaria3. Sufre el enfermo, sufre su familia y puede sufrir el profesional que les atiende. Sin embargo, una lectura detenida de los trabajos nos permite ser optimistas porque se ve cómo la enfermedad puede ser también ocasión de crecimiento personal para los diferentes agentes implicados

Derivatives and Inverse of a Linear-Nonlinear Multi-Layer Spatial Vision Model

Analyzing the mathematical properties of perceptually meaningful linear-nonlinear transforms is interesting because this computation is at the core of many vision models. Here we make such analysis in detail using a specific model [Malo & Simoncelli, SPIE Human Vision Electr. Imag. 2015] which is illustrative because it consists of a cascade of standard linear-nonlinear modules. The interest of the analytic results and the numerical methods involved transcend the particular model because of the ubiquity of the linear-nonlinear structure. Here we extend [Malo&Simoncelli 15] by considering 4 layers: (1) linear spectral integration and nonlinear brightness response, (2) definition of local contrast by using linear filters and divisive normalization, (3) linear CSF filter and nonlinear local con- trast masking, and (4) linear wavelet-like decomposition and nonlinear divisive normalization to account for orientation and scale-dependent masking. The extra layers were measured using Maximum Differentiation [Malo et al. VSS 2016]. First, we describe the general architecture using a unified notation in which every module is composed by isomorphic linear and nonlinear transforms. The chain-rule is interesting to simplify the analysis of systems with this modular architecture, and invertibility is related to the non-singularity of the Jacobian matrices. Second, we consider the details of the four layers in our particular model, and how they improve the original version of the model. Third, we explicitly list the derivatives of every module, which are relevant for the definition of perceptual distances, perceptual gradient descent, and characterization of the deformation of space. Fourth, we address the inverse, and we find different analytical and numerical problems in each specific module. Solutions are proposed for all of them. Finally, we describe through examples how to use the toolbox to apply and check the above theory. In summary, the formulation and toolbox are ready to explore the geometric and perceptual issues addressed in the introductory section (giving all the technical information that was missing in [Malo&Simoncelli 15])

Bronchiectasis-COPD Overlap Syndrome: Role of Peripheral Eosinophil Count and Inhaled Corticosteroid Treatment

Both chronic obstructive pulmonary disease and bronchiectasis are highly prevalent diseases. In both cases, inhaled corticosteroids (ICs) are associated with a decrease in exacerbations in patients with a high peripheral blood eosinophil count (BEC), but it is still not known what occurs in bronchiectasis-COPD overlap syndrome (BCOS). The present study aimed to assess the effect of ICs on various outcomes in patients with BCOS, according to BEC values. We undertook a post-hoc analysis of a cohort of 201 GOLD II-IV COPD patients with a long-term follow-up (median 74 [IQR: 40-106] months). All participants underwent computerized tomography and 115 (57.2%) had confirmed BCOS. A standardized clinical protocol was followed and two sputum samples were collected at each medical visit (every 3-6 months), whenever possible. During follow-up, there were 68 deaths (59.1%), and the mean rate of exacerbations and hospitalizations per year was 1.42 (1.2) and 0.57 (0.83), respectively. A total of 44.3% of the patients presented at least one pneumonic episode per year. The mean value of eosinophils was 402 (112) eosinophils/mu L, with 27 (23.5%), 63 (54.8%), and 25 patients (21.7%) presenting, respectively, less than 100, 101-300, and more than 300 eosinophils/mu L. A total of 84 patients (73.1%) took ICs. The higher the BEC, the higher the annual rate of exacerbations and hospitalizations. Patients with less than 100 eosinophils/mu L presented more infectious events (incident exacerbations, pneumonic episodes, and chronic bronchial infection via pathogenic bacteria). Only those patients with eosinophilia (>300 eosinophils/mu L) treated with ICs decreased the number (1.77 (1.2) vs. 1.08 (0.6), p < 0.001) and the severity (0.67 (0.8) vs. 0.35 (0.5), p = 0.011) of exacerbations, without any changes in the other infectious outcomes or mortality. In conclusion, ICs treatment in patients with BCOS with increased BEC decreased the number and severity of incident exacerbations without any negative influence on other infectious outcomes (incidence of pneumonia or chronic bronchial infection)

Association among salivary alpha-amylase activity and working memory functioning in healthy children

Salivary Alpha-Amylase (sAA) shows a statistically significant association with levels of peripheral noradrenaline under acute psychosocial stress conditions in young and healthy participants. In this study, our aim was directed to examine the relation among sAA and cognitive performance in various executive tasks in an experimental sample composed by 69 healthy children although we only could obtain the complete set of data for 44 boys and girls for this battery. The cogni- tive tasks employed were: Digits, Letters & Numbers, Arithmetic and Visual Span subtests of WISC-V (this full set of subtests is employed to the assessment of verbal and visual working memory). Saliva samples were obtained at baseline (10 minutes before the start of neuropsychological assessment), one minute before the start, after the end of the verbal tasks, and one minute after the end of the visual span task. Our statistical analyses showed a significant association among sAA levels and some of the parameters employed to describe the perfor- mance of each participant in the subscales of Digits and Letters & Numbers after controlling the effect of BMI. Scores in Letters & Numbers and visual span were associated with levels of salivary flow rate. These results are coherent with the findings of a previous pilot study conducted in our laboratory and are interpreted in relation with those results which have suggested a main role of the Locus Coeruleus-Noradrenaline System (LC-NA System) in the regulation of the level of arousal and executive behaviors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

High-Throughput 16S rRNA Sequencing to Assess Potentially Active Bacteria and Foodborne Pathogens: A Case Example in Ready-to-Eat Food

Technologies to detect the entire bacterial diversity spectra and foodborne pathogens in food represent a fundamental advantage in the control of foodborne illness. Here, we applied high-throughput 16S rRNA sequencing of amplicons obtained by PCR and RT-PCR from extracted DNA and RNA targeting the entire bacterial community and the active bacterial fraction present in some of the most consumed and distributed ready-to-eat (RTE) salad brands in Europe. Customer demands for RTE food are increasing worldwide along with the number of associated foodborne illness and outbreaks. The total aerobic bacterial count in the analyzed samples was in the range of 2–4 × 106 CFU/g (SD ± 1.54 × 106). Culture validated methods did not detect Salmonella spp., Escherichia coli, and other fecal coliforms. 16S rRNA gene Illumina next-generation sequencing (NGS) data were congruent with these culture-based results and confirmed that these and other well-known foodborne bacterial pathogens, such as Listeria, were not detected. However, the fine-resolution of the NGS method unveiled the presence of the opportunistic pathogens Aeromonas hydrophyla and Rahnella aquatilis (relative frequency of 1.33–7.33%) that were metabolically active in addition to non-pathogenic, active members of Yersinia spp. (relative frequency of 0.0015–0.003%). The common ail and foxA marker genes of Yersinia enterocolitica were not detected by qPCR. Finally, our NGS data identified to non-pathogenic Pseudomonas spp. as the most abundant and metabolically active bacteria in the analyzed RTE salads (53–75% of bacterial abundance). Our data demonstrate the power of sequencing, in parallel, both 16S rRNA and rDNA to identify and discriminate those potentially and metabolically active bacteria and pathogens to provide a more complete view that facilitates the control of foodborne diseases, although further work should be conducted to determine the sensitivity of this method for targeting bacteria.This work was supported by the Spanish Ministry of Economy and Competitiveness (ref. RTI2018-094248-B-I00) and the Gordon and Betty Moore Foundation (grant 5334)