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PublicationA parametric 3D-printed body-powered hand prosthesis based on the four-bar linkage mechanism(Institute of Electrical and Electronics Engineers Inc., 2018)
;Bustamante M. ;Vega-Centeno R. ;Sánchez M.Mio R.The widespread of 3D-printing technology has resulted in the appearance of many open-source prosthetic hand models, especially for partial hand amputations. However, most of these designs are not editable and while some are parametric to some degree, customization for every user is limited to scaling the size of a base design. As consequence, most prostheses fail to closely match the user specific anthropometry and have poor aesthetics, which could result in abandonment of the device. Furthermore, achieving a high degree of customization could be a time-consuming task and requires previous knowledge of CAD design. This work presents a prosthetic hand easy to customize by changing parametric dimensions of the finger phalanges and palm on an Excel sheet. Additionally, the design tackles common issues from previous 3D-printed body-powered prosthetic hands by incorporating new features such as the use of linkages instead of cables as finger flexors and a new cable-adjusting system which requires no additional tools and makes the tensioning of finger tendons easier and quicker. © 2018 IEEE.Scopus© Citations 8 -
PublicationAnalysis of the Massbauer quadrupole spectra of some amorphous fluoridesQuadrupole distribution fits have been made of high-statistics Mössbauer spectra of some amorphous fluorides. The most important role of the value given to linewidth is considered. To analyze the resulting P(), the ratio q=22 is calculated and compared to the values of Czjzek's model. The data are analyzed for amorphous KFeF4 samples and for various glasses whose homogeneity was also ascertained. © 1983 The American Physical Society.
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PublicationAntineutrino Charged-Current Reactions on Hydrocarbon with Low Momentum Transfer(Grupo Amapolas, 2018-06-01)
;Ray, Dueñas ;ARAMBURU LOPEZ DE ROMAÑA, CARLOS EDUARDO FELIX ;CORDOVA SALAS, CARLOS RICARDOPontificia Universidad Católica del PerúWe report on multinucleon effects in low momentum transfer (<0.8 GeV/c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei. © 2018 authors. Published by the American Physical Society.Scopus© Citations 24 -
PublicationArmonizando tensiones: La necesidad de transparencia en el arbitraje sin destruir la confidencialidad( 2020-01-01)En el presente artículo, el autor analiza el paradigma clásico de la confidencialidad en el arbitraje comercial y las posturas de los principales centros arbitrales del mundo. Posteriormente, profundiza sobre la necesidad de transparencia en el arbitraje. Finalmente, plantea una serie de medidas que se deberían poner en práctica para desarrollar la transparencia sin dejar de lado la confidencialidad.
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PublicationAssessment of supervised classifiers for the task of detecting messages with suicidal ideation( 2020-08-01)
;Acuña Caicedo R.W. ;Gómez Soriano J.M.Melgar Sasieta H.A.According to the World Health Organization (WHO) close to 800,000 people worldwide die by suicide each year, and many more attempts to do it. In consequence, the WHO recognizes suicide as a global public health priority, which affects not only rich countries but poor and middle-income countries as well. This study makes a systematic analysis of 28 supervised classifiers using different features of the corpus Life to detect messages with suicidal ideation and depression to know if these can be used in an automatic prevention online system. The Life Corpus, used in this research, is a bilingual text corpus (English and Spanish) oriented to the detection of suicide ideation. This corpus was constructed retrieving texts from several social networks and its quality was measured using mutual annotation agreement. The different experiments determined that the classifier with the best performance was KStar, with the corpus features POS-SYNSETS-NUM, achieving the best results with the ROC Area metrics of 0,81036 and F-measure of 0,7148. The present research fulfilled the objective of discovering which supervised classifiers and which features are the most suitable for the automatic classification of messages with suicidal ideation using the Life Corpus. Also, given the imbalance of the results, a new precision measure was developed called the Two-dimensional Accuracy and Recovery Index (GDP), which can provide better results, in unbalanced systems, than the usual measures to assess the quality of the results (measure F, Area ROC), and thus increase the number of messages at risk of suicidal ideation, detected at the cost of receiving more messages that are not related to suicide or vice versa. -
PublicationAutomatic classification of pediatric pneumonia based on lung ultrasound pattern recognition(Public Library of Science, 2018)
;Barrientos F. ;Barrientos R. ;Román-Gonzalez A. ;Pajuelo M.J. ;Anticona C. ;Mayta H. ;Alva A. ;Solis-Vasquez L. ;Figueroa D.A. ;Chavez M.A. ;Lavarello R. ;CASTAÑEDA APHAN, BENJAMIN ;Paz-Soldán V.A. ;Checkley W. ;Gilman R.H.Oberhelman R.Pneumonia is one of the major causes of child mortality, yet with a timely diagnosis, it is usually curable with antibiotic therapy. In many developing regions, diagnosing pneumonia remains a challenge, due to shortages of medical resources. Lung ultrasound has proved to be a useful tool to detect lung consolidation as evidence of pneumonia. However, diagnosis of pneumonia by ultrasound has limitations: it is operator-dependent, and it needs to be carried out and interpreted by trained personnel. Pattern recognition and image analysis is a potential tool to enable automatic diagnosis of pneumonia consolidation without requiring an expert analyst. This paper presents a method for automatic classification of pneumonia using ultrasound imaging of the lungs and pattern recognition. The approach presented here is based on the analysis of brightness distribution patterns present in rectangular segments (here called “characteristic vectors“) from the ultrasound digital images. In a first step we identified and eliminated the skin and subcutaneous tissue (fat and muscle) in lung ultrasound frames, and the “characteristic vectors”were analyzed using standard neural networks using artificial intelligence methods. We analyzed 60 lung ultrasound frames corresponding to 21 children under age 5 years (15 children with confirmed pneumonia by clinical examination and X-rays, and 6 children with no pulmonary disease) from a hospital based population in Lima, Peru. Lung ultrasound images were obtained using an Ultrasonix ultrasound device. A total of 1450 positive (pneumonia) and 1605 negative (normal lung) vectors were analyzed with standard neural networks, and used to create an algorithm to differentiate lung infiltrates from healthy lung. A neural network was trained using the algorithm and it was able to correctly identify pneumonia infiltrates, with 90.9% sensitivity and 100% specificity. This approach may be used to develop operator-independent computer algorithms for pneumonia diagnosis using ultrasound in young children. © 2018 Correa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Scopus© Citations 61 -
PublicationBlackbody-radiation-induced resonances between Rydberg-Stark states of Na(American Physical Society, 35431)
;DE ZELA MARTINEZ, FRANCISCO ANTONIOMASSONI KAMIMOTO, EDUARDO RUBENWe report on measurements of the population of Rydberg states of Na in a constant electric field that result when 300-K blackbody radiation induces transitions from initial states with m=0,1 to neighboring states. Our measurements included comprehensive ranges of initial states ([Formula Presented]=24–29), repopulation times ([Formula Presented]=0–50 μs), and fields ([Formula Presented]=175–712 V/cm). We find that the population is redistributed nonuniformly among states neighboring the initial state, reflective of sharp resonances between the states. By comparing calculations of transition probabilities in Na to the data for [Formula Presented]=200 V/cm we were able to identify the populated states. Comparisons with calculations in H reveal that these resonances are hydrogenic. © 1997 The American Physical Society. -
PublicationControl inteligente de sistemas e iluminación en edificios(Universidad Nacional de Piura, 2017-09-18)
;Huamán Rojas, Jezzy James ;Ipanaqué Alama, William ;GIACOMOTTI TUEZTA JOSE GUILLERMO ;Ausenco PerúAusenco PerúLa tesis desarrolla un controlador adaptativo para el control inteligente de la iluminación en cualquier ambiente, esto considera edificios, casas, oficinas, entre otros. Se presentan dos opciones de controlador y, para considerarlo un sistema inteligente, este se adapta al usuario haciendo uso de la tecnología de aprendizaje automático y regulable. Redes neuronales artificiales y árboles de decisión se emplean para adecuar la iluminación sin dejar de cumplir las normas que se establecen por función de los ambientes, en tanto se considera que la iluminación pueda verse afectada por muchos factores, incluyendo el color de las paredes y techos. Los controladores por tanto, no pueden ser del tipo estándar, es por ello que se ha desarrollado un controlador PID adaptativo, obteniéndose un sistema embebido como sistema de regulación y como controlador del nivel mínimo de iluminación un control PID adaptativo sin identificación. -
PublicationCorrection to: Predicting Mechanical Ventilation Using the EGRIS in Guillain–Barré Syndrome in a Latin American Country (Neurocritical Care, (2021), 10.1007/s12028-021-01218-z)( 2021-10-01)
;Malaga M. ;Rodriguez-Calienes A. ;Marquez-Nakamatsu A. ;Recuay K. ;Merzthal L. ;Bustamante-Paytan D. ;Sifuentes J.M. ;Castillo-Kohatsu G.Alva-Diaz C.The original article has been updated to correct affiliations of corresponding author Carlos Alva-DiazScopus© Citations 1 -
PublicationCOVID-19, Non-Communicable Diseases, and Behavioral Factors in the Peruvian Population ≥ 15 Years: An Ecological Study during the First and Second Year of the COVID-19 Pandemic( 2022-09-01)
;Canorio J. ;Sánchez F.Ramírez-Soto M.C.A range of health-related and behavioral risk factors are associated with COVID-19 incidence and mortality. In the present study, we assess the association between incidence, mortality, and case fatality rate due to COVID-19 and the prevalence of hypertension, obesity, overweight, tobacco and alcohol use in the Peruvian population aged ≥15 years during the first and second year of the COVID-19 pandemic. In this ecological study, we used the prevalence rates of hypertension, overweight, obesity, tobacco, and alcohol use obtained from the Encuesta Demográfica y de Salud Familiar (ENDES) 2020 and 2021. We estimated the crude incidence and mortality rates (per 100,000 habitants) and case fatality rate (%) of COVID-19 in 25 Peruvian regions using data from the Peruvian Ministry of Health that were accurate as of 31 December 2021. Spearman correlation and lineal regression analysis was applied to assess the correlations between the study variables as well as multivariable regression analysis adjusted by confounding factors affecting the incidence and mortality rate and case fatality rate of COVID-19. In 2020, adjusted by confounding factors, the prevalence rate of obesity (β = 0.582; p = 0.037) was found to be associated with the COVID-19 mortality rate (per 100,000 habitants). There was also an association between obesity and the COVID-19 case fatality rate (β = 0.993; p = 0.014). In 2021, the prevalence of obesity was also found to be associated with the COVID-19 mortality rate (β = 0.713; p = 0.028); however, adjusted by confounding factors, including COVID-19 vaccination coverage rates, no association was found between the obesity prevalence and the COVID-19 mortality rate (β = 0.031; p = 0.895). In summary, Peruvian regions with higher obesity prevalence rates had higher COVID-19 mortality and case fatality rates during the first year of the COVID-19 pandemic. However, adjusted by the COVID-19 vaccination coverage, no association between the obesity prevalence rate and the COVID-19 mortality rate was found during the second year of the COVID-19 pandemic. -
PublicationDetecting Gender and Racial Discrimination in Hiring Through Monitoring Intermediation Services: The Case of Selected Occupations in Metropolitan Lima, Peru( 2012-02-01)
;Ñopo H. ;Saavedra J.Torero M.Inspired by audit studies methodology, we monitored a job intermediation service in Peru to detect gender and racial discrimination in hiring. We capture individual racial information using the approach of Ñopo, Saavedra, and Torero (2007), enabling a richer exploration of racial differences. Overall, the study finds discriminatory treatment in hiring only when comparing groups with extremely different observable racial characteristics. We detect discriminatory treatment for female Indigenous applicants in secretarial positions. In terms of aimed wages, females tend to ask for wages 7% below those of males with comparable skills (although this has no negative impact on wages at hiring). © 2011 Elsevier Ltd. -
PublicationDiagnostics barriers and innovations in rural areas: Insights from junior medical doctors on the frontlines of rural care in Peru( 2015-10-05)
;Huaynate C.F.A. ;Travezaño M.J.P. ;Malpartida H.M. ;Oberhelman R. ;Murphy L.L.Paz-Soldan V.A.Background: Worldwide, rural communities face barriers when accessing health services. In response, numerous initiatives have focused on fostering technological innovations, new management approaches and health policies. Research suggests that the most successful innovations are those involving stakeholders at all levels. However, there is little evidence exploring the opinions of local health providers that could contribute with further innovation development and research. The aims of this study were to explore the perspectives of medical doctors (MDS) working in rural areas of Peru, regarding the barriers impacting the diagnostic process, and ideas for diagnostic innovations that could assist them. Methods: Data gathered through three focus group discussions (FGG) and 18 individual semi-structured interviews (SSI) with MDS who had completed their medical service in rural areas of Peru in the last two years were analyzed using thematic analysis. Results: Three types of barriers emerged. The first barrier was the limited access to point of care (POC) diagnostic tools. Tests were needed for: i) the differential diagnosis of malaria vs. pneumonia, ii) dengue vs. leptospirosis, iii) tuberculosis, iv) vaginal infections and cervical cancer, v) neurocysticercosis, and vi) heavy metal toxicity. Ultrasound was needed for the diagnosis of obstetric and intra-Abdominal conditions. There were also health system-related barriers such as limited funding for diagnostic services, shortage of specialists, limited laboratory services and access to telecommunications, and lack of institutional support. Finally, the third type of barriers included patient related-barriers to follow through with diagnostic referrals. Ideas for innovations proposed included POC equipment and tests, and telemedicine. Conclusions: MDS at primary health facilities in rural Peru face diagnostic challenges that are difficult to overcome due to a limited access to diagnostic tools. Referrals to specialized facilities are constrained by deficiencies in the organization of health services and by barriers that impede the patients' travel to distant health facilities. Technological innovations suggested by the participants such as POC diagnostic tools and mobile-health (m-health) applications could help address part of the problem. However, other types of innovation to address social, adaptation and policy issues should not be dismissed.Scopus© Citations 39 -
PublicationDirect Measurement of Nuclear Dependence of Charged Current Quasielasticlike Neutrino Interactions Using MINERvA(Fondo Editorial de la PUCP, 2017-08-25)
;QUISPE MELGAR, HAROLD RUSBELTH ;Manrique Muñante, Rubén Eduardo ;QUISPE MELGAR, HAROLD RUSBELTHPontificia Universidad Católica del PerúCharged-current νμ interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q2, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q2 and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different models of both initial state nucleons and final state interactions used in the neutrino oscillation experiments. © 2017 American Physical Society. © 2017 American Physical Society.Scopus© Citations 33 -
PublicationDynamics of ethnic and racial self-identification in contemporary Peru( 2019-07-27)Benavides M.This study has sought to analyse how the social and cultural dynamics of the population are expressed in the recent processes of ethnic self-identification in Peru. Data from 2012 to 2016 Peru National Household survey was used to investigate specifically: (a) on the contribution of the questions about ethnic and racial self-identification included in the National Household Survey to the visibility of indigenous and Afro-Peruvian populations; (b) on the individual and local characteristics related with certain self-identification categories; and (c) if the self-identification patterns have remained stable or have varied during the survey period. Results show that the number of persons who identifies as indigenous varies according to the question used. Likewise, it was found that characteristics such as age, migratory experience, education, and income level influence on the self-identification. Finally, modest but significant changes over time were registered, which could be shedding light on some processes of social transformations.
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PublicationEthno-racial identification in urban Peru( 2012-07-01)Oropesa R.This study examines ethno-racial identification among urban Peruvians, with special attention to those who are at risk of 'de-Indianizing'. Specifically, we use a nationally representative survey to describe how city residents classify themselves and how self-classifications are associated with primordial and circumstantial characteristics. Consistent with official statistics, a large majority identifies as mestizo. However, the share that self-identifies as indigenous is much smaller than expected from official language-based criteria or from appearance alone. Moreover, identification is rooted in primordial characteristics associated with descent and the family-of-origin's linguistic environment, particularly for those with indigenous ancestries. Identification is also linked to socio-economic circumstances and perceived discrimination. © 2012 Copyright Taylor and Francis Group, LLC.
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PublicationEvaluation of the best new cross-ply laminated plate theories through the Axiomatic/Asymptotic Approach(Shahid Chamran University of Ahvaz, 2018-01-01)
;Candiotti S.Mantari J.L.This paper presents Best Theory Diagrams (BTDs) constructed from various non-polynomial theories for the static analysis of thick and thin symmetric and asymmetric cross-ply laminated plates. The BTD is a curve that provides the minimum number of unknown variables necessary for a fixed error or vice versa. The plate theories that belong to the BTD have been obtained by means of the Axiomatic/Asymptotic Method (AAM). The different plate theories reported are implemented by using the Carrera Unified Formulation (CUF). Navier-type solutions have been obtained for the case of simply- supported plates loaded by a bisinuisoidal transverse pressure with different lengthto- thickness ratios. The BTDs built from non-polynomials functions are compared with BTDs using Maclaurin expansion. The results suggest that the plate models obtained from the BTD using non-polynomial terms can improve the accuracy obtained from Maclaurin expansions for a given number of unknown variables of the displacement field.Scopus© Citations 4 -
PublicationExpansion of the agrarian and demographic frontier in the Peruvian selva.(Frontier expansion in Amazonia, 30682)MASSONI KAMIMOTO, EDUARDO RUBENOutlines the history, population processes, and expansion of the demographic frontier, by giving demographic and socioeconomic data. Discusses colonization of the selva alta, migration, and expansion of the peasant economy.-C.J.Barrow(CDS)
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PublicationExtraction of the Third( 2020-11-14)
;Ray, Dueñas RDGrupo de investigación en BiomedicinaResumen de prueba -
PublicationFabrication of Sub-10-nm Plasmonic Gaps for Ultra-Sensitive Raman Spectroscopy( 2016-12-29)
;Cetin A.E. ;Yilmaz C. ;Yilmaz G. ;Altug H.The past two decades have witnessed the explosion of activities in the field of surface enhanced Raman spectroscopy (SERS). SERS platforms employ nano-structures that excite plasmonic modes with large local electromagnetic fields localized within small gap spaces between each constituting feature. Although the research-oriented SERS platforms yield significant signal enhancements to identify even single molecules, practical SERS-based sensors have not been fully introduced yet. The main reason behind this absence is the need for a cost-effective and reliable manufacturing method for controllable fabrication of plasmonic nano-gaps over large areas. In this article, we introduced a novel manufacturing process that enables fast and scalable fabrication of highly uniform sub-10-nm gaps that could yield large SERS signals. In this process, a conventional electroplating technique is used to produce unique nano-mushroom antenna arrays on a conducting substrate, resulting in controllable gap spaces between mushroom heads. By understanding the nature of mushroom shape antenna formation, we demonstrated the control of inter-metallic gaps down to 5 nm. We showed that the manufactured nano-structures yield Raman enhancements more than 108. Providing such large SERS signals that are uniform over large areas, our cost-effective fabrication technique could be very critical to realize practical SERS devices.Scopus© Citations 14