A comparative study of steganography using watermarking and modifications pixels versus least significant bit

This article presents a steganography proposal based on embedding data expressed in base 10 by directly replacing the pixel values from images red, green blue (RGB) with a novel compression technique based on watermarks. The method considers a manipulation of the object to be embedded through a data compression triple process via LZ77 and base 64, watermark from low-quality images, embedded via discrete wavelet transformation-singular value decomposition (DWT-SVD), message embedded by watermark is recovered with data loss calculated, the watermark image and lost data is compressed again using LZ77 and base 64 to generate the final message. The final message is embedded in portable network graphic (PNG) images taken from the Microsoft common objects in context (COCO), ImageNet and uncompressed color image database (UCID) datasets, through a filtering process pixel of the images, where the selected pixels expressed in base 10, and the final message data is embedded by replacing units’ position of each pixel. In experimentation results an average of 40 dB in peak signal noise to ratio (PSNR) and 0.98 in the similarity structural index metric (SSIM) evaluation were obtained, and evasion steganalysis rates of up to 93% for stego-images, the data embedded average is 3.2 bpp

El tiempo satírico

It is said traditionally that the present is the temporal axis common to the satiric genre. To justify this assertion, one can usually draw on arguments like the characteristical satiric tendency to use the narrative first person. In this paper, having exposed the different theoretical perspectives about this theme, it can be concluded that the satiric present is an intemporal literary creation oposed to the also intemporal literary past, represented by the concept of mores maiorum.It is said traditionally that the present is the temporal axis common to the satiric genre. To justify this assertion, one can usually draw on arguments like the characteristical satiric tendency to use the narrative first person. In this paper, having exposed the different theoretical perspectives about this theme, it can be concluded that the satiric present is an intemporal literary creation oposed to the also intemporal literary past, represented by the concept of mores maiorum

Autoconcepto en educación física para mejorar la salud escolar pospandemia

Self-concept is one of the key aspects of personality development. It is relevant because it affects how a person sees him/herself and how he/she relates to others. During adolescence, self-perception tends to be highly variable due to the inherent changes of this stage, being a critical period in which to foster a healthy and confident personality. Add to this the critical circumstances experienced during the pandemic and it becomes a bombshell. Physical education classes, can promote the self-concept and improve school health. The aim of the study was to analyse self-concept in Spanish adolescents of physical education by sex, school location, age, educational level and body mass index (BMI) after the pandemic. A crosssectional study of 961 students’ physical education classes in public schools in Extremadura (Spain) was obtained and administered the Self-Concept Questionnaire version 5 (AF-5). The results showed that there is an association between AF-5 and sex, where adolescent girls have lower self-concept; there is a slight inverse relationship between AF-5 with age and BMI and there is no significant association between AF-5 and school location. In conclusion, knowing the relevant factors of self-concept after covid allows the educational community to implement tools for the optimal development of self-concept in Physical Education students, thus performance of adolescents.El autoconcepto es uno de los aspectos clave del desarrollo de la personalidad. Es relevante porque afecta cómo una persona se ve a sí misma y cómo se relaciona con los demás. Durante la adolescencia la autopercepción suele ser muy variable debido a los cambios inherentes a esta etapa, siendo un periodo crítico para fomentar una personalidad sana y segura. Si a esto le sumamos las circunstancias críticas vividas durante la pandemia, se convierte en un bombazo. Las clases de educación física, pueden favorecer el autoconcepto y mejorar la salud escolar. El objetivo del estudio fue analizar el autoconcepto en adolescentes españoles de educación física según sexo, localización escolar, edad, nivel educativo e índice de masa corporal (IMC) tras la pandemia. Se realizó un estudio transversal de 961 alumnos de clases de educación física de colegios públicos de Extremadura (España), a los que se les aplicó el Cuestionario de Autoconcepto versión 5 (AF-5). Los resultados mostraron que existe asociación entre AF-5 y el sexo, donde las adolescentes tienen un menor autoconcepto; existe una ligera relación inversa entre AF-5 con la edad y el IMC y no existe una asociación significativa entre AF-5 y la ubicación de la escuela. En conclusión, conocer los factores relevantes del autoconcepto post covid permite a la comunidad educativa implementar herramientas para el óptimo desarrollo del autoconcepto en los estudiantes de Educación Física y con ello del desempeño de los adolescentes

A Forward Application of Age Associated Gray and White Matter Networks

To capture patterns of normal age-associated atrophy, we previously used a multivariate statistical approach applied to voxel based morphometry that identified age-associated gray and white matter covariance networks (Brickman et al. [2007]: Neurobiol Aging 28:284-295). The current study sought to examine the stability of these patterns by forward applying the identified networks to an independent sample of neurologically healthy younger and older adults. Forty-two younger and 35 older adults were imaged with standard high-resolution structural magnetic resonance imaging. Individual images were spatially normalized and segmented into gray and white matter. Covariance patterns that were previously identified with scaled subprofile model analyses were prospectively applied to the current sample to identify to what degree the age-associated patterns were manifested. Older individuals were also assessed with a modified version of the Mini Mental State Examination (mMMSE). Gray matter covariance pattern expression discriminated between younger and older participants with high optimal sensitivity (100%) and specificity (90.5%). While the two groups differed in the degree of white matter pattern expression (t (75) = 5.26, P < 0.001), classification based on white matter expression was relatively low (sensitivity = 80% and specificity = 61.9%). Among older adults, chronological age was significantly associated with increased gray matter pattern expression (r (32) = 0.591, P < 0.001) but not with performance on the mMMSE (r (31) = -0.314, P = 0.085). However, gray matter pattern expression was significantly associated with performance on the mMMSE (r (31) = -0.405, P = 0.024). The findings suggest that the previously derived age-associated covariance pattern for gray matter is reliable and may provide information that is more functionally meaningful than chronological age

A cryptic RNA-binding domain mediates Syncrip recognition and exosomal partitioning of miRNA targets

Exosomal miRNA transfer is a mechanism for cell-cell communication that is important in the immune response, in the functioning of the nervous system and in cancer. Syncrip/hnRNPQ is a highly conserved RNA-binding protein that mediates the exosomal partition of a set of miRNAs. Here, we report that Syncrip's amino-terminal domain, which was previously thought to mediate protein-protein interactions, is a cryptic, conserved and sequence-specific RNA-binding domain, designated NURR (N-terminal unit for RNA recognition). The NURR domain mediates the specific recognition of a short hEXO sequence defining Syncrip exosomal miRNA targets, and is coupled by a non-canonical structural element to Syncrip's RRM domains to achieve high-affinity miRNA binding. As a consequence, Syncrip-mediated selection of the target miRNAs implies both recognition of the hEXO sequence by the NURR domain and binding of the RRM domains 5′ to this sequence. This structural arrangement enables Syncrip-mediated selection of miRNAs with different seed sequences. © 2018 The Author(s)

Prevalence of Depression and Depressive Symptoms Among Resident Physicians: A Systematic Review and Meta-analysis.

IMPORTANCE: Physicians in training are at high risk for depression. However, the estimated prevalence of this disorder varies substantially between studies. OBJECTIVE: To provide a summary estimate of depression or depressive symptom prevalence among resident physicians. DATA SOURCES AND STUDY SELECTION: Systematic search of EMBASE, ERIC, MEDLINE, and PsycINFO for studies with information on the prevalence of depression or depressive symptoms among resident physicians published between January 1963 and September 2015. Studies were eligible for inclusion if they were published in the peer-reviewed literature and used a validated method to assess for depression or depressive symptoms. DATA EXTRACTION AND SYNTHESIS: Information on study characteristics and depression or depressive symptom prevalence was extracted independently by 2 trained investigators. Estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were estimated using meta-regression. MAIN OUTCOMES AND MEASURES: Point or period prevalence of depression or depressive symptoms as assessed by structured interview or validated questionnaire. RESULTS: Data were extracted from 31 cross-sectional studies (9447 individuals) and 23 longitudinal studies (8113 individuals). Three studies used clinical interviews and 51 used self-report instruments. The overall pooled prevalence of depression or depressive symptoms was 28.8% (4969/17,560 individuals, 95% CI, 25.3%-32.5%), with high between-study heterogeneity (Q = 1247, τ2 = 0.39, I2 = 95.8%, P < .001). Prevalence estimates ranged from 20.9% for the 9-item Patient Health Questionnaire with a cutoff of 10 or more (741/3577 individuals, 95% CI, 17.5%-24.7%, Q = 14.4, τ2 = 0.04, I2 = 79.2%) to 43.2% for the 2-item PRIME-MD (1349/2891 individuals, 95% CI, 37.6%-49.0%, Q = 45.6, τ2 = 0.09, I2 = 84.6%). There was an increased prevalence with increasing calendar year (slope = 0.5% increase per year, adjusted for assessment modality; 95% CI, 0.03%-0.9%, P = .04). In a secondary analysis of 7 longitudinal studies, the median absolute increase in depressive symptoms with the onset of residency training was 15.8% (range, 0.3%-26.3%; relative risk, 4.5). No statistically significant differences were observed between cross-sectional vs longitudinal studies, studies of only interns vs only upper-level residents, or studies of nonsurgical vs both nonsurgical and surgical residents. CONCLUSIONS AND RELEVANCE: In this systematic review, the summary estimate of the prevalence of depression or depressive symptoms among resident physicians was 28.8%, ranging from 20.9% to 43.2% depending on the instrument used, and increased with calendar year. Further research is needed to identify effective strategies for preventing and treating depression among physicians in training

Teachers´ work in adults secondary educations classrooms: a challenge of pedagogical practices

La educación de personas adultas es una estructura necesaria para responder algunos de los grandes desafíos que urge enfrentar en estos tiempos de crisis. Sin embargo, los centros de educación de personas adultas son los grandes desconocidos del sistema educativo. Por ello esta investigación pretende describir y comprender la labor docente que se realiza en sus aulas de educación secundaria. Dada la naturaleza cualitativa de nuestra investigación, se opta por un estudio colectivo de casos de corte etnográfico en una estancia en el campo por dos años. Las evidencias empíricas se recogieron a través de la observación participante y la realización de entrevistas semiestructuradas que se realizaron en dos CEPA de dos municipios de la Comunidad de Madrid. Los resultados describen el peculiar funcionamiento de un aula de secundaria de personas adultas y la especificidad de las tareas docentes que allí se desarrollan. A la luz de estos resultados, subrayamos la conveniencia de plantear en la formación docente conocimientos que aborden la singularidad de esta modalidad educativa en un mundo en el que todavía existen 770 millones de personas analfabetas, altas tasas de abandono escolar temprano en las sociedades occidentales, un envejecimiento progresivo de la población, nuevos retos formativos asociados a la digitalización de la vida y una emergencia sanitaria y climática que exige nuevas formas de ser y estar en el mundoAdult education is a necessary structuretor espond to some of the great challenges that we urgently need to face in the setimes of crisis. However,adult education centre sare the great unknown softhe educations sytem.Forthisreason,this research a imstodescrib e andunderstand the tea ching work carried out in their secondar y education classrooms.Given the qualitative nature of ourresearch ,weoptedfora collective ethnographic casestudy during at wo-yearstayinthefield.Empirical evidence was collected through participant observationand semi-structured interviews in two adult education centre soft wo citiesin the Community of Madrid.The results describe the peculiar functionin go fan adul tsecondary schoo lclassroom and the specificit y oftheteaching tasks carrie dout there.In the ligh to fthese results,we underline the convenience of introducing in teacher trainin g knowledge that addresses theuniquenes soft his educational modality in a world where there are still millionillite rate people,high rate sofearly schoo ldropoutin Western societies,aprogressive agein go fthe population ,new training challenges associated with the digitalisation of life and a health and climate emergency that demands new way sofbeingand being in the worl

Photoproduction of meson and baryon resonances in a chiral unitary approach

By means of a coupled channel non-perturbative unitary approach, it is possible to extend the strong constrains of Chiral Perturbation Theory to higher energies. In particular, it is possible to reproduce the lowest lying resonances in meson-meson scattering up to 1.2 GeV using the parameters of the O(p^2) and O(p^4) Chiral Lagrangian. The meson baryon sector can also be tackled along similar lines. We report on an update of these results showing some examples of photon induced reactions where the techniques have been recently applied.Comment: Contribution to the Erice Summer School of Nuclear Physics, 21th course: Electromagnetic Probes and the Structure of Hadrons and Nuclei September 17th - 25th, 1999, Erice/Sicily/Ital