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In this paper a class of regular surfaces, generated by rotation and twist of a rigid line segment, is considered. Firstly a complete description of those surfaces by means of local charts is obtained and then its orientability is characterized in terms of the number of half-twists, taking into account their direction (clockwise or counterclockwise) since changes in the sense of twist are allowed. Indeed a procedure to construct nonorientable surfaces is provided. Illustrative examples and computer-generated plots using the free software "Maxima" are included.

Vocabulary tests, once a cornerstone of language modeling evaluation, have been largely overlooked in the current landscape of Large Language Models (LLMs) like Llama 2, Mistral, and GPT. While most LLM evaluation benchmarks focus on specific tasks or domain-specific knowledge, they often neglect the fundamental linguistic aspects of language understanding. In this paper, we advocate for the revival of vocabulary tests as a valuable tool for assessing LLM performance. We evaluate seven LLMs using two vocabulary test formats across two languages and uncover surprising gaps in their lexical knowledge. These findings shed light on the intricacies of LLM word representations, their learning mechanisms, and performance variations across models and languages. Moreover, the ability to automatically generate and perform vocabulary tests offers new opportunities to expand the approach and provide a more complete picture of LLMs' language skills. [ABSTRACT FROM AUTHOR]

In May and June 2024, a die‐off of Mexican mantled howler monkeys (Alouatta palliata mexicana) occurred in southern Mexico. This commentary documents the event, attributing it to extreme heatwaves, drought, wildfires, and habitat impoverishment. Despite their reported resilience to habitat disturbances, mantled howler monkey mortality rate in some areas reached 31%. Key evidence points to heatstroke as the primary cause of death, exacerbated by limited hydration and reduced dietary diversity in disturbed habitats. Immediate responses included community‐led rescues (e.g., hydrating the monkeys), coordination of rescue activities by nongovernmental organizations (NGOs) (e.g., managing donations), involvement of scientists (e.g., monitoring of primate populations), and assistance from government officials (e.g., providing legal support for animal management). This event underscores the urgency of developing action plans to prevent and attend future crises. Among other actions, we highlight (i) establishing primate care infrastructure with medical and rehabilitation centers; (ii) developing protocols and training programs to ensure rapid crisis response; (iii) fostering collaboration among government, NGOs, and academic institutions for effective crisis management; and (iv) developing targeted research on climate change impacts, predictive models, and long‐term health monitoring. We emphasize the critical need for coordinated conservation efforts to protect wild primates and maintain natural ecosystem resilience in the face of escalating climate challenges. Summary: In May and June 2024, over 300 howler monkeys died in southern Mexico.Key evidence points to heatstroke as the primary cause of death, exacerbated by limited hydration and reduced dietary diversity in disturbed habitats.This event highlights the critical need for coordinated conservation efforts to protect wild primates in the face of escalating climate challenges. [ABSTRACT FROM AUTHOR]

Background: The main goal of a health system is to maintain or improve people's health. The COVID-19 pandemic showed the fragility of health systems worldwide. In Mexico, the pandemic affected the performance of the health system, along with the presence of contextual conditions such as its segmentation and high prevalence of chronic diseases. Aims: To analyze from an approach to the functions of the health system, the service delivery, human resources, financing, and stewardship/governance in the local health services of five states of Mexico, from the perspective of the staff working in health centers. Methods: This is an exploratory qualitative study conducted from November 2020 to August 2021, involving 124 health professionals from 39 health facilities (18 rural and 21 urban). The technique used was the semi-structured interview. Interview guides were developed according to core topics. Subsequently, the thematic analysis method was used. Results: The lack of financial resources delayed prevention efforts and made it difficult for health centers to adapt to the crisis. Inequity was found in the distributive efficiency of staff between rural and urban areas and levels of care. In addition, there was evidence of capacity for coordination, capacity sharing, and joint participation between health institutions, civil authorities, and the population to face the emergency. Conclusions: We identified relevant public health actions that showed the capacity of local health services to organize a response to the pandemic at the level of the actors responsible for these services. [ABSTRACT FROM AUTHOR]

The concept of resilience was applied to the public health field to investigate the way health systems are impacted by health crises, what conditions allow them to mitigate the blow and how they reorganize once the crisis is over. In 2020, the COVID-19 pandemic caused by the SARS-CoV-2 virus represented a global challenge demanding immediate response to an unprecedented health crisis. Various voices drew attention to the intensity of the crisis in countries with greater inequalities, where the pandemic converged with other social emergencies. We documented the experiences of health personnel who faced the pandemic at the primary care level while simultaneously maintaining the functioning of other areas of medical care. Our results derived from a qualitative study comprising 103 participants from five states of Mexico. We aimed to show through inferential analysis their perspective on what we call 'the resilience of local health systems'. We observed three stages of experience during the crisis: (a) Preparation (official guidelines received to organize care, training and planning of epidemiological surveillance); (b) Adaptation (performance of community-based prevention activities, infrastructure modifications, telehealth); and (c) Learning (participatory governance with city councils, business sector and organized population). The study suggests that the local health systems analysed benefited from the initiatives of health personnel that in some cases positively exceeded their duties. In terms of the resilience analysis, they were able to handle the impact of the crisis and cope with it. Their transformative capacity came from the strategies implemented to adapt health services by managing institutional resources. Their experience represents a lesson on the strengthening of the essential functions of health systems and shows a way to address successfully the increasingly complex health challenges of the present and future times. [ABSTRACT FROM AUTHOR]

Android malware has emerged as a consequence of the increasing popularity of smartphones and tablets. While most previous work focuses on inherent characteristics of Android apps to detect malware, this study analyses indirect features and metadata to identify patterns in malware applications. Our experiments show the following: (1) the permissions used by an application offer only moderate performance results; (2) other features publicly available at Android markets are more relevant in detecting malware, such as the application developer and certificate issuer; and (3) compact and efficient classifiers can be constructed for the early detection of malware applications prior to code inspection or sandboxing. [ABSTRACT FROM AUTHOR]

A resilience analysis of protection cycles ( p-cycle) configurations for Double Rings with Dual Attachment (DRDAs) architectures is presented in this work. DRDAs are composed of two rings with corresponding nodes connected by two separated links. There are several possible configurations of p-cycles, which may be used in DRDAs for improving link or node protection upon link failure. The values of the parameters Mean Time To Failure and Mean Time To Disconnection are analysed in the paper to show the best choice of p-cycles in DRDAs architectures. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT This work provides a novel measurement-based analysis of the tweet arrival traffic process at Twitter. The analysis considers more than one million total tweets collected at 48 different times of the day (o'clock and half-past every hour). We observe a 3.5-tweet/ms average rate with a valley of 2.5 tweets/ms at 10 AM (GMT+1) and a peak at 3 PM (GMT+1) of about 5 tweets/ms. We further model the traffic pattern as a Gaussian process, and we validate such an assumption with multiple normality tests. Finally, we overview a number of applications where such a model may show its utility, namely infrastructure dimensioning and upgrading, the detection of outlier events, energy efficiency and so on. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Rheumatoid Arthritis (RA) is a chronic inflammatory disease, symmetrical and polyarticular, and incapacitating. In Rheumatology department, in Institute Salvadoreno del Seguro Social (ISSS), is one of the main causes of appointment and is responsible for many disabilities and premature death. The aim of the study was to describe the main demographic, clinical characteristics and a sample taken from laboratory of patients with RA who are treated in this medical center. The type of the study was observational, descriptive, and cross sectional. Six hundred and eighty six patients diagnosed with RA were included. An 89.2 were women with an average age of 50.2 (21-84 years old). The level of education was similar in both sexes; it showed that 3.4% was illiterate. A 45.3% of referred patients for the first time to doctor appointment had less than three years of evolution of the disease, and 21.3% had more than ten years of evolution; which was closely related to greater degree of disability, (9.7% was in Stage III or IV). A 62.2% had positive rheumatoid factor. In conclusion, we found that rheumatoid arthritis is a disease affecting the 89.2% of women with a mean age of 50.2. Around half of patients (45.3%) are promptly referred to Rheumatology, which reflects a lower degree of disability. [ABSTRACT FROM AUTHOR]

The proposed Energy-Efficient Ethernet (EEE) standard reduces energy consumption by defining two operation modes for transmitters and receivers: active and low power. Burst transmission can provide additional energy savings when EEE is used. Collecting data frames into large-sized data bursts for back-to-back transmission maximizes the time an EEE device spends in low power, thus making its consumption nearly proportional to its traffic load. An initial evaluation shows that the additional savings in the scenarios considered range from 5 to 70 percent for conventional users and approximately 50 percent for large data centers. [ABSTRACT FROM AUTHOR]

Often, Internet measurement-based studies have followed a three-step procedure: collection of network measurements; measurementbased model inference; and generalization of the results obtained to other scenarios. Indeed, it has been a general belief that certain internetwork traffic statistics, such as the most used IP addresses and port numbers, show a similar behavior in networks with similar features, and the conclusions derived from the measurements of a given network could be extrapolated to a similar scenario. This study makes no starting assumption concerning this issue and undertakes a "spatial" analysis of network measurements. The measurement set comprises a six-month trace collected by RedIRIS (the Spanish National Research and Education Network) at different monitored points acrossthe country. Our experiment shows that, although the frequency statistics of IP addresses and port numbers follow a Zipf distribution (as expected), the distributions' characteristic parameter values vary significantly in a spatial dimension (i.e., across individual university networks), even when the profile of the networks' user bases are similar. In practical terms, this means network designers, analysts, and operators should not assume that statistics for Internet site and applications usage for one network may accurately characterize other networks, even when those networks have similar user bases and environments. Furthermore, we show that experiment durations of approximately 30 days are necessary for the traffic processes to display stationarity. Hence, in order to obtain accurate statistics on traffic characteristics of large internetworks using state-of-the-art measurement techniques, long and spatially diverse experiments may be necessary. [ABSTRACT FROM AUTHOR]

The particular statistical properties found in network measurements, namely self-similarity and long-range dependence, cannot be ignored in modeling network and Internet traffic. Thus, despite their mathematical tractability, traditional Markov models are not appropriate for this purpose, since their memoryless nature contradicts the burstiness of transmitted packets. However, it is desirable to find a similarly tractable model which is, at the same time, rigorous at capturing the features of network traffic. This work presents discrete-time heavy-tailed chains, a tractable approach to characterize network traffic as a superposition of discrete-time "on/off" sources. This is a particular case of the generic "on/off" heavy-tailed model, thus shows the same statistical features as the former, particularly self-similarity and long-range dependence, when the number of aggregated sources approaches infinity. The model is then applicable to characterize a number of discrete-time communication systems, for instance, ATM and optical packet switching, to further derive meaningful performance metrics such as average burst duration and the number of active sources in a random instant. [ABSTRACT FROM AUTHOR]

Automobile security became an essential theme over the last years, and some automakers invested much money for collision avoidance systems, but personalization of their driving systems based on the user's behavior was not explored in detail. Furthermore, efficiency gains could be had with tailored systems. In Mexico, 80% of automobile accidents are caused by human beings; the remaining 20% are related to other issues such as mechanical problems. Thus, 80% represents a significant opportunity to improve safety and explore driving efficiency gains. Moreover, when driving aggressively, it could be connected with mental health as a post-traumatic stress disorder. This paper proposes a Tailored Collision Mitigation Braking System, which evaluates the driver's personality driving treats through signal detection theory to create a cognitive map that understands the driving personality of the driver. In this way, aggressive driving can be detected; the system is then trained to recognize the personality trait of the driver and select the appropriate stimuli to achieve the optimal driving output. As a result, when aggressive driving is detected continuously, an automatic alert could be sent to the health specialists regarding particular risky behavior linked with mental problems or drug consumption. Thus, the driving profile test could also be used as a detector for health problems. [ABSTRACT FROM AUTHOR]

We propose an approximation algorithm for scheduling jobs with release and delivery times on a single machine with the objective to minimize the makespan. The algorithm is based on an implicit enumeration of the set of complete solutions in a search tree. By analyzing specific structural properties of the solutions created in each branch of the solution tree, a certain approximation factor of each solution from that branch is calculated. Our algorithm guarantees approximation factor 1 + 1 / κ for a generated solution if there are κ jobs with a specified property in that solution (typically, the longer the length of the path from the root to the node representing that solution in the solution tree, the larger the κ value). We have carried out an extensive computational study to verify the practical performance of our algorithm and the effectiveness of the approximation factor provided by us. While our problem instances are generated randomly, we have discarded a considerable number of the instances, ones which were already solved optimally by the earlier known dominance rules. For the vast majority of the tested problem instances, within a short running time of our algorithm parameter κ becomes sufficiently large so that the approximation factor which the algorithm guarantees becomes better than that provided by the earlier known approximation algorithms. [ABSTRACT FROM AUTHOR]