Longer Trails Research Articles

Trans Canada trail: A shared-use network of pathways from coast to coast to coast

When Canada celebrated its 125th anniversary in 1992, an initiative was launched to have a Trans Canada Trail (TCT) by 2017—Canada's 150th anniversary, to pass through thousands of municipalities and communities from the Atlantic to the Pacific and, further, the Arctic coast. With a total length of over 27,000 km at present, the Trans Canada Trail has become the world's longest trail, which allows millions of users to be actively engaged in a variety of outdoor activities. The TCT brings Canadian citizens closer to nature while engendering a host of recreation and learning opportunities as well as health benefits. This study describes the evolution and milestones of the TCT initiative. A conceptual framework that embodies a Nature Continuum typology is proposed for exploring the relationships among the trail activities, trail types and the environment. The results lend support to certain elements of the Nature Continuum typology. A number of gaps of the TCT are identified, and necessary measures for addressing the gaps are discussed. Uniting Canadians physically and symbolically, the TCT is, nevertheless, a work in progress. An array of hurdles need to be surmounted down the road for the Trans Canada Trail to fulfill its mantle of aiding Canadians in their journey of active living. The Trans Canada Trail enables Canadians to stay active and close to nature. The study shows that the ‘Nature Continuum’ typology is a promising tool for managers to examine relationships between human activities and the environment along the Urban-Wilderness Spectrum. Managers of national trails should establish a national code of ethics including strategies to deal with trail users, to respect all signage and property, to avoid environmental damage, to inform trail users, to leave wildlife and plants alone and to stay on the trail. A national code of ethics will contribute to the desired behavioral change over time.

Performance and Training Load Profiles in Recreational Male Trail Runners: Analyzing Their Interactions during Competitions.

Endurance sports like trail running constitute an extensive individual modality causing numerous physiological changes to occur in the athlete. In this sense, an adequate monitoring of training load appears to be essential to improve competition performance. The aim of this study was two-fold: (i) to analyze trail runners’ weekly load variations in the four weeks leading up to a trail running competition, and (ii) to determine the relationship between the runners’ pacing in competitions and their physical fitness and workload parameters. Twenty-five amateur male trail runners (age: 36.23 ± 8.30 years old; minimum International Trail Running Association performance index: 600) were monitored daily for the duration of a season (52 weeks). External load (distance covered, pace) and internal load (rate of perceived exertion) were measured daily. Additionally, weekly workload measures of acute:chronic workload ratio (ACWR), training monotony, and training strain were calculated. The runners were also assessed for maximal aerobic speed (MAS) every four months. No significant differences in workload measures (p > 0.05) were observed in the four weeks leading up to each short trail competition; however, leading up to the long trail, ultra-trail medium, and ultra-trail long/extra-long competitions, the differences in the runners’ workload measures were significant (p < 0.05). In the short trail, pace was found to be moderately correlated with the ACWR of total distance (r = −0.334) and with training monotony of rate of perceived exertion (RPE) (r = −0.303). In the ultra-trail, a large correlation was observed between pace and elevation accumulated (r = 0.677). We concluded that significant workload differences from one week to the next only occurred in preparation for longer-distance competitions, with sudden acute load decreases and very low ACWR values reported mainly in weeks 1 and 2 of the taper. Meaningful relationships were found between performance (pace) and MAS for longer trails and between pace and MAS for ultra-trail competitions.

New techniques for trail bounds and application to differential trails in Keccak

We present new techniques to efficiently scan the space of high-probability differential trails in bit-oriented ciphers. Differential trails consist in sequences of state patterns that we represent as ordered lists of basic components in order to arrange them in a tree. The task of generating trails with probability above some threshold starts with the traversal of the tree. Our choice of basic components allows us to efficiently prune the tree based on the fact that we can tightly bound the probability of all descendants for any node. Then we extend the state patterns resulting from the tree traversal into longer trails using similar bounding techniques. We apply these techniques to the 4 largest Keccak-f permutations, for which we are able to scan the space of trails with weight per round of 15. This space is orders of magnitude larger than previously best result published on Keccak-f[1600] that reached 12, which in turn is orders of magnitude larger than any published results achieved with standard tools, that reached at most 9. As a result we provide new and improved bounds for the minimum weight of differential trails on 3, 4, 5 and 6 rounds. We also report on new trails that are, to the best of our knowledge, the ones with the highest known probability.

New techniques for trail bounds and application to differential trails in Keccak

We present new techniques to efficiently scan the space of high-probability differential trails in bit-oriented ciphers. Differential trails consist in sequences of state patterns that we represent as ordered lists of basic components in order to arrange them in a tree. The task of generating trails with probability above some threshold starts with the traversal of the tree. Our choice of basic components allows us to efficiently prune the tree based on the fact that we can tightly bound the probability of all descendants for any node. Then we extend the state patterns resulting from the tree traversal into longer trails using similar bounding techniques. We apply these techniques to the 4 largest Keccak- f permutations, for which we are able to scan the space of trails with weight per round of 15. This space is orders of magnitude larger than previously best result published on Keccak- f [1600] that reached 12, which in turn is orders of magnitude larger than any published results achieved with standard tools, that reached at most 9. As a result we provide new and improved bounds for the minimum weight of differential trails on 3, 4, 5 and 6 rounds. We also report on new trails that are, to the best of our knowledge, the ones with the highest known probability.

Fast Food Delivery: Is There a Way for Foraging Success in Leaf-Cutting Ants?

Walking long distances through a trail system is an intrinsic feature of the leaf-cutting ants. Workers travel hundred of meters to forage by using well-defined physical routes which are cleared of vegetation or obstacles. Despite the costs of construction and maintenance, cleared trails should promote more benefits than non-physical ones, especially related to the leaf supply for the colony. Here, the leaf delivery rate in constructed and non-constructed trails was compared by counting the foraging flow and travel time of workers. Also the length and width of trails were measured. It was found that leaf delivery rate was 67.47% higher for foragers who were walking along physical trails. The forager walking speed on physical trails had an increment of 86.10% . These significant increments might be related to the truly narrow corridor present inside physical trails that are leaf litter-free, and thereby chemically stronger and smoother than non-physical ones. The speed improvement could induce the construction of longer trails which guide the workers more efficiently to the foraging patch. Thus, physical trails have an important role in foraging efficiency as they allow workers go quickly and further to forage, since they limit a path and congregate more individuals, raising the leaf delivery rate. This study provides additional information about foraging trails of leaf-cutting ants.

Anthropometric measures and cognition in middle-aged HIV-infected and uninfected women. The Women’s Interagency HIV Study

This study aimed to explore the relationship of body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR) with cognition in women with (HIV+) and without HIV (HIV-) infection. One thousand six hundred ninety participants (1,196 HIV+, 494 HIV-) in the Women's Interagency HIV Study (WIHS) with data available on anthropometric measures comprise the analytical sample. Cross-sectional analyses using linear regression models estimated the relationship between anthropometric variables and Trails A, Trails B, Stroop interference time, Stroop word recall, Stroop color naming and reading, and Symbol Digit Modalities Test (SDMT) with consideration for age, HIV infection status, Wide Range Achievement Test score, CD4 count, insulin resistance, drug use, and race/ethnicity. Among HIV+ women, BMI < 18.5 kg/m(2) was associated with poorer cognitive performance evidenced by longer Trails A and Trails B and shorter SDMT completion times. An obese BMI (30 kg/m(2) or higher) was related to better performance on Trails B and worse performance on the Stroop interference test. Among HIV- women, an obese BMI was related to worse performance on the Stroop color naming test. Few and inconsistent associations were observed between WC, WHR, and cognition. Among women at mid-life with chronic (at least 10 years) HIV infection, common anthropometric measures, primarily BMI, were differentially related to cognitive test performance by cognitive domain. Higher levels of BMI were associated with better cognitive function. In this era of antiretroviral therapies, restoration of health evidenced as higher BMI due to effective antiretroviral therapies, may improve cognitive function in middle-aged HIV-infected women.

The relationship between cognitive performance, perceptions of driving comfort and abilities, and self-reported driving restrictions among healthy older drivers

The objective of the present study was to examine the relationship between cognitive performance, driver perceptions and self-reported driving restrictions. A cross-sectional analysis was conducted on baseline data from Candrive II, a five-year prospective cohort study of 928 older drivers aged 70–94 years from seven cities. Cognitive performance was assessed using the Montreal Cognitive Assessment (MoCA) as well as the Trail Making Test, parts A and B. Driver perceptions were assessed using the Day and Night Driving Comfort Scales and the Perceived Driving Abilities scale, while driving practices were captured by the Situational Driving Frequency and Avoidance scales, as well as the Driving Habits and Intentions Questionnaire. The baseline data indicates this cohort is largely a cognitively intact group. Univariate regression analysis showed that longer Trails A and B completion times were significantly, but only modestly associated with reduced driving frequency and perceived driving abilities and comfort, as well as a significant tendency to avoid more difficult driving situations (all p<.05). Most of these associations persisted after adjusting for age and sex, as well as indicators of health, vision, mood and physical functioning. Exceptions were Trails A and B completion times and situational driving frequency, as well as time to complete Trails B and current driving restrictions. After adjusting for the confounding factors, the total MoCA score was not associated with any of the driving measure scores while the number of errors on Trails A was significantly associated only with situational driving frequency and number of errors on Trails B was significantly associated only with situational driving avoidance. Prospective follow-up will permit examination of whether baseline cognition or changes in cognition are associated with changes in driver perceptions, actual driving restrictions and on-road driving outcomes (e.g., crashes, violations) over time.

Atividade forrageadora de &lt;em&gt;Acromyrmex laticeps nigrosetosus&lt;/em&gt; Forel (Hymenoptera: Formicidae) em povoamento de eucalipto

Observou-se, de novembro de 1994 a fevereiro de 1995, a atividade forrageadora de duas colônias de Acromyrmex laticeps nigrosetosus Forel em área reflorestada com eucalipto, Eucalyptus camaldulensis (Myrtaceae), em Paraopeba, Minas Gerais, Brasil. Essas colônias foram monitoradas por dois ciclos consecutivos de 24 horas por mês, tendo sido observado que a atividade dessas colônias foi predominantemente noturna, com correlação negativa, entre o fluxo de operárias nas trilhas e a temperatura do ar, e positiva, com a umidade relativa do ar. A área média explorada, durante o forrageamento, foi de 9,24 m². Foram observadas trilhas mais longas quando não havia trilhas secundárias. O comprimento médio de forrageamento foi de 4,08 m, variando de 2,10 a 8,83 m

Performance on Original and a Chinese Version of Trail Making Test Part B: A Normative Bilingual Sample

This study examined an equivalent of Trail Making Test Part B for native Chinese speakers. Digit Symbol Coding and Trail Making Test Parts A and B were administered to American and Chinese students from an American university. The Chinese group also took a modified Trails B test where numbers in Chinese characters replaced English letters. Independent-samples t tests showed no difference between American and Chinese groups on the Digit Symbol Coding and Trails A, but a difference on Trails B (p < .05). The Chinese group's modified Trails B performance showed no difference from the American group's original Trails B performance. These findings suggest equivalence of Digit Symbol Coding and Trails A for American and Chinese groups, but a longer Trails B completion time for the Chinese group. This finding indicates a language bias of Trails B for Chinese-English bilinguals. Thus, the Chinese version of Trails B is preferable for native Chinese speakers.

The Longest Trail

The Longest Trail