A quadric representation of pseudo-Riemannian product immersions

In this paper we introduce a quadric representation φ of the product of two pseudo-Riemannian isometric immersions. We characterize the product of submanifolds whose quadric representation satisfies △Hφ=λHφ、for a real constant λ, where Hφ is the mean curvature vector field of .φ As for hypersurfaces, we prove that the only ones satisfying that equation are minimal products as well as products of a minimal hypersurface and another one which has constant mean and constant scalar curvatures with an appropriate relation between them. In particular, the family of these surfaces consists of H2(-1) and S1(2/3)×1(-2) in S13(1) and S12(1), H11(-2/3)×1(2). S11(2)×1(-2/3) and a B-scroll over a null Frenet curve with torsion ±√2 in H13(-1)

Translation of Pronominal Anaphora between English and Spanish: Discrepancies and Evaluation

This paper evaluates the different tasks carried out in the translation of pronominal anaphora in a machine translation (MT) system. The MT interlingua approach named AGIR (Anaphora Generation with an Interlingua Representation) improves upon other proposals presented to date because it is able to translate intersentential anaphors, detect co-reference chains, and translate Spanish zero pronouns into English---issues hardly considered by other systems. The paper presents the resolution and evaluation of these anaphora problems in AGIR with the use of different kinds of knowledge (lexical, morphological, syntactic, and semantic). The translation of English and Spanish anaphoric third-person personal pronouns (including Spanish zero pronouns) into the target language has been evaluated on unrestricted corpora. We have obtained a precision of 80.4% and 84.8% in the translation of Spanish and English pronouns, respectively. Although we have only studied the Spanish and English languages, our approach can be easily extended to other languages such as Portuguese, Italian, or Japanese

Colorectal cancer population screening programs worldwide in 2016: An update

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The incidence and mortality show wide geographical variations. Screening is recommended to reduce both incidence and mortality. However, there are significant differences among studies in implementation strategies and detection. This review aimed to present the results and strategies of different screening programs worldwide. We reviewed the literature on national and international screening programs published in PubMed, on web pages, and in clinical guidelines. CRC Screening programs are currently underway in most European countries, Canada, specific regions in North and South America, Asia, and Oceania. The most extensive screening strategies were based on fecal occult blood testing, and more recently, the fecal immunochemical test (FIT). Participation in screening has varied greatly among different programs. The Netherlands showed the highest participation rate (68.2%) and some areas of Canada showed the lowest (16%). Participation rates were highest among women and in programs that used the FIT test. Men exhibited the greatest number of positive results. The FIT test has been the most widely used screening program worldwide. The advent of this test has increased participation rates and the detection of positive results

Stress detection using wearable physiological and sociometric sensors

Stress remains a significant social problem for individuals in modern societies. This paper presents a machine learning approach for the automatic detection of stress of people in a social situation by combining two sensor systems that capture physiological and social responses. We compare the performance using different classifiers including support vector machine, AdaBoost, and k-nearest neighbour. Our experimental results show that by combining the measurements from both sensor systems, we could accurately discriminate between stressful and neutral situations during a controlled Trier social stress test (TSST). Moreover, this paper assesses the discriminative ability of each sensor modality individually and considers their suitability for real time stress detection. Finally, we present an study of the most discriminative features for stress detection

Usability assessment of a greenhouse context-aware alert system for small-scale farmers

In the dynamic landscape of modern agriculture, integrating technology holds immense potential to enhance efficiency and productivity for small-scale farmers. This study presents a user-centric evaluation of an intelligent context-aware alert system, tailored for small-scale greenhouse farming. We employed standardized questionnaires, including the NASA Task Load Index and the User Experience Questionnaire, to assess the system's perceived utility, mental workload, and overall user experience. Our findings reveal the high perceived utility of the system among farmers. Farmers participating in the assessment indicated a strong intention to utilize the system for crop monitoring. Moreover, the system demonstrated a moderate mental workload, suggesting ease of use and potential acceptance by users. Our evaluation highlighted an excellent user experience, with scores ranging from very good to extremely good across all dimensions. Furthermore, user preferences for alert mechanisms underscored the importance of adaptable notifications, with voice and text alerts favored for comprehensive information dissemination. Light and voice alerts were preferred during manual tasks. This study highlights the significance of user-centered design in agricultural technology, offering insights to enhance the usability and the adoption of alert systems in small-scale farming environments. The positive reception of the system's utility and the moderate mental workload suggest that such technology can be readily adopted by farmers, thereby improving monitoring and management practices in greenhouse farming. The preference for adaptable alert mechanisms further emphasizes the need for flexible and context-sensitive solutions in agricultural technology.This work was partially supported by the Research Center in Information and Communication Technologies (CITIC) and the School of Computer Science and Informatics (ECCI) at the University of Costa Rica, Research Project No. 834-B9-189. This study forms part of the AGROALNEXT program and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and Generalitat Valenciana (Spain)

Assessment of the retinal nerve fiber layer in individuals with obstructive sleep apnea

Background: The effect of obstructive sleep apnea (OSA) syndrome in the peripapillary retinal nerve fiber layer (RNFL) thicknesses remains unclear. The purpose of this study was to assess RNFL measurements acquired using scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in patients with OSA. Methods: The sample of this cross-sectional study included 40 OSA patients and 45 age-matched controls, consecutively and prospectively selected. All participants underwent at least one reliable standard automated perimetry (SAP) test, while RNFL measurements were obtained using the SLP and OCT. The OSA group was divided into 3 sub-groups based on the apnea/hypopnea index (AHI): mild, moderate, or severe OSA. SAP, SLP, and OCT outcomes were compared between the control and OSA groups. The relationship between AHI and RNFL parameters was also evaluated. Results: Age was not different between both groups. Mean deviation of SAP was -0.47 ± 0.9 dB and -1.43 ± 2.3 dB in the control and OSA groups, respectively (p = 0.01). RNFL thickness measured with OCT was similar between groups. OSA patients showed increased nerve fiber indicator (NFI; 20.9 ± 7.9 versus 16.42 ± 7.82; p = 0.01) and decreased superior average (59.74 ± 10.35 versus 63.73 ± 6.58; p = 0.03) obtained with SLP compared with healthy individuals. In the total sample, NFI and AHI were moderately correlated (r = 0.358; p = 0.001). In severe OSA subjects (n = 22), NFI and AHI had a Spearman correlation coefficient of 0.44 (p = 0.04). Conclusion: RNFL thickness measured with OCT did not differ significantly between groups. Severe OSA was related to a reduction of the RNFL thickness assessed by SLP